Zirconia-mullite composite ceramics were fabricated by in-situ controlled crystallization of Si-Al-Zr-O amorphous bulk. The effects of TiO₂ addition on the fabrication of zirconia-mullite composites were investigated. The ultra-fine zirconia-mullite composite ceramics were prepared from the amorphous bulk treated at 980 °C for nucleation and 1 140 °C for crystallization. The phase transformation of the ceramics was examined using differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). The microstructural features of the samples were evaluated with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and transmission electron microscopy (TEM). The mechanical properties were also determined using Vickers indentation. The results show that the TiO₂ additives with mass fraction of 1%–7% reduce the formation temperature of t-ZrO₂ and mullite. When the mass fraction of TiO₂ additives is less than 5%, the phases do not change, and most of TiO₂ dissolves in ZrO₂. When the mass fraction of TiO₂ additives is over 5%, the excessive TiO₂ forms a new phase, ZrTiO₄. Meanwhile, the results also show that TiO₂ additives have a great impact on the microstructure and mechanical properties of zirconia-mullite composites. As the TiO₂ content increases from 1% to 7% (mass fraction), the grain size and the Vickers hardness of zirconia-mullite composites increase. The composite with 3% (mass fraction) TiO₂ additives attains relatively higher fracture toughness.

Tribological characteristics and self-repairing effect of hydroxy-magnesium silicate (HMS) dispersed in lubricant oil on steel-to-steel friction pairs with various surface roughness were analyzed. The friction-reduction, anti-wear and self-repairing performance of various surface roughness friction pairs were examined by friction testing machine. An operation comparison was made between SJ10W-40 lubricant with and without HMS. The surface morphology and elementary composition of the grinding cracks were analyzed by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results show that the lubrication state changes from boundary lubrication into mixed lubrication after operation in lubricant with HMS. The friction-reduction, anti-wear and self-repairing performance of the friction pairs with various surface roughness are distinctly different. There is a repairing film whose material is different from substrate material on the grinding cracks. In addition, Si, Mg, O, Al and other elements are deposited on the repairing film which contains nanocrystals of these elements. And HMS self-repairing material possesses superior performance of friction-reduction, anti-wear and self-repairing effects.

Ni-Cr/h-BN self-lubricating composities were prepared by powder metallurgy (P/M) method. The effects of hexagonal boron nitride (h-BN) content on the mechanical and tribological properties of the Ni-Cr/h-BN composites were investigated. The corresponding frictional models were established to analyze the formation of the lubricant h-BN films on the surfaces of the Ni-Cr/h-BN composites. The results show that, when the content of h-BN increases from 5% to 15% (mass fraction), the bending strength of the Ni-Cr/h-BN composite decreases from 96.670 MPa to 17.319 MPa, and the hardness (HB) decreases from 33 to 14. The friction coefficient of the Ni-Cr/h-BN composite decreases firstly from 0.385 to 0.216, and then increases to 0.284, while the wear rate decreases firstly from 4.14×10⁻⁹ kg/(N·m) to 1.35×10⁻⁹ kg/(N·m), then increases to 2.36×10⁻⁹ kg/(N·m). The best comprehensive mechanical and tribological properties can be obtained between 10% and 12% h-BN addition.

To provide theoretical basis and practical guidance for preparing composite rods of external diameter no larger than 12 mm by directly continuous casting, low melting point materials of lead and tin were selected to prepare composite rods of external diameter 12 mm and inner diameter 8 mm with air pressing core filled continuous casting process. The orthogonal tests consisting of three factors and three levels were designed to investigate the parameters of melting lead temperature, continuous casting speed and air pressure that affect the performance of the composite rods. The results show that melting lead temperature is the most important factor that influences the solid/liquid interface location; continuous casting speed is the most important factor that influences the surface quality and lead and tin inter-diffusion amount; air pressure can improve the surface quality obviously and make the rods easily drawn out, but the surface quality cannot get obvious improvement when the air pressure is above 0.03 MPa. The composite rods have excellent surface quality, obvious intermediate layer, even thick clad, and metallurgical bonding interface under the condition of melting lead temperature of 375 °C, continuous casting speed of 10 mm/min, and air pressure of 0.03 MPa.

The influence of thermomechanical aging on microstructure and mechanical properties of 2519A aluminum alloy was investigated by means of microhardness test, tensile test, optical microscopy (OM) and transmission electron microscopy (TEM). The results show that 50% cold rolling deformation prior to aging is beneficial since it promotes a more homogeneous distribution of the precipitation phase and reduces the number of precipitation phase on the grain boundaries, and thus shrinks the total volume of precipitation-free zones at grain and sub-grain boundaries. As a result, the tensile properties of 2519A aluminum alloy have been significantly improved.

Oxidation behaviors of blank and CeO₂ coated T91 steel were investigated at 600 °C in water vapor for up to 150 h. Gold marker was used to define the mass transport direction. The oxide scales were studied with X-ray diffractometry (XRD), scanning electron microscopy (SEM) and electron probe microanalyzer (EPMA). The oxidation resistance of the steel is improved by CeO₂ coating, though the improvement is not remarkable. Ce-rich oxide band is located at the interface of the inner equiaxed layer and the outer columnar layer after oxidation, which is not consistent with the original surface. The results show that outward iron transport is blocked by the Ce-rich band. A new oxide nucleating and growing site (reaction front) is induced at the inner surface of the Ce rich band.

The effects of B₂O₃ addition on both the sintering behavior and microwave dielectric properties of CaO-B₂O₃-SiO₂ (CBS) glass ceramics were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results show that the increasing amount of B₂O₃ causes the increase of the contents of [BO₃], [BO₄] and [SiO₄], which deduces the increase of CaB₂O₄ and α-SiO₂ and the decrease of CaSiO₃ correspondingly. No new phase is observed throughout the entire experiments. A bulk density of 2.54 g/cm³, a thermal expansion coefficient value of 11.95×10⁻⁶°C⁻¹ (20–500°C), a dielectric constant ɛ_r value of 6.42 and a dielectric loss tanδ value of 0.000 9 (measured at 9.7 GHz) are obtained for CBS glass ceramics containing 35% B₂O₃ (mass fraction) sintered at 850 °C for 15 min.

Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin. It was found that both the amount of tannin and the small triangular silver nanoplate seeds added to the growth solution are the key factors to modulation absorption band of triangular silver nanoplates. The optical in-plane dipole surface plasmon resonance (SPR) bands of these Ag nanoplates can be tuned from 608 nm to 980 nm via tannin deoxidization method. The formation mechanism of triangular silver nanoplates was proposed. The tannin deoxidization method realizes a convenient modulation of the absorption band of Ag nanostructures within the visible near-infrared (IR) region both in aqueous solvent and on substrates under mild conditions.

Monodispersed manganese ferrite (MnFe₂O₄) nanocrystals could be successfully synthesized in large quantities via a facile synthetic technique based on the pyrolysis of organometallic compound precursor, in which octadecene was used as solvent, and oleic acid and oleylamine were used as capping ligands. MnFe₂O₄ nanocrystals were obtained with size in a tunable range of 4–15 nm and their morphologies could be tuned from spherical to triangle-shaped by varying the surfactants. The phase structure, morphology, and size of the products were characterized in detail by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Magnetic properties of MnFe₂O₄ nanocrystals with different morphologies were measured using a superconducting quantum interference device (SQUID). Both monodisperse MnFe₂O₄ nanocrystals with spherical and triangle-shapes are superparamagnetic at room temperature while ferromagnetic at 2 K. The pyrolysis method may provide an effective route to synthesize other spinel ferrites or metal oxides nanocrystals.

Well-crystallized hexagonal hematite (α-Fe₂O₃) platelets were synthesized by hydrothermal process, using a highly concentrated ferric hydroxide as precursor. The precursor was prepared by adding ammonia to the ferric sulfate solution which was obtained by leaching pyrite cinders with sulfuric acid. Structure and morphology of the synthesized products were investigated by X-ray diffraction, scanning electron microscope, transmission electron microscope and selected area electron diffraction. The results reveal that the reaction temperature has significant effects on the structure, size and shape of the synthesized hematite particles. Typical hexagonal hematite platelets, about 0.4–0.6 μm in diameter and 0.1 μm in thickness, were prepared at 230 °C for 0.5 h. Al³⁺, contained in the sulfuric acid leaching solution as an impurity, plays an extremely important role in the formation of hexagonal hematite. In addition, a possible mechanism about the formation of hexagonal hematite platelets was proposed.

The fluidization behavior of SiO₂, ZnO and TiO₂ non-magnetic nanoparticles was investigated in a magnetically fluidized bed (MFB) by adding coarse magnets. The effects of both the amount of coarse magnets and the magnetic field intensity on the fluidization quality of these nanoparticles were investigated. The results show that the coarse magnets added to the bed lead to a reduction in the size of the aggregates formed naturally by the primary nanoparticles. As the macroscopic performances of improved fluidization quality, the bed expansion ratio increases whilst the minimum fluidization velocity decreases with increasing the magnetic field intensity, but for TiO₂ nanoparticles there exists a suitable magnetic field intensity of 0.059 6 T. The optimal amounts of coarse magnets for SiO₂, ZnO and TiO₂ non-magnetic nanoparticles are 40%, 50% and 60% (mass fraction), respectively. The bed expansion results analyzed by the Richardson-Zaki scaling law show that the exponents depend on both the amount of coarse magnets and the magnetic field intensity.

Electrochimcal behaviors of rusticyanin (Rus.) isolated from Acidithiobacillus ferrooxidans were investigated through Rus.-ZnS-QDs/L-Cys/Au electrode. The cyclic voltammetric results indicate that rusticyanin immobilized on the surface of Rus.-ZnS-QDs/L-Cys/Au electrode can undergo a direct quasi-reversible electrochemical reaction. The immobilized rusticyanin is not denatured and still retains its activity in the temperature range of 19–43 °C. The reduction ability of the protein increases and its oxidation ability becomes weak with the increase of pH from 6.0 to 7.8. Fe²⁺ ions in the solution can promote the electron transfer kinetics of the immobilized rusticyanin and make its peak potentials (φ_p) markedly move negatively.

To further test whether polynitriprismanes are capable of being potential high energy density materials (HEDMs), extensive theoretical calculations were carried out to investigate on a series of polynitrotriprismanes (PNNPs): C₆H_6−n(NO₂)_n (n=1−6). Heats of formation (HOFs), strain energies (SE), and disproportionation energy (DE) were obtained using B3LYP/6-311+G(2df, 2p)//B3LYP/6-31G* method by designing different isodesmic reactions, respectively. Detonation properties of PNNPs were obtained by the well-known KAMLET-JACOBS equations, using the predicted densities (ρ) obtained by Monte Carlo method and HOFs. It is found that they increase as the number of nitro groups n varies from 1 to 6, and PNNPs with n≥4 have excellent detonation properties. The relative stability and the pyrolysis mechanism of PNNPs were evaluated by the calculated bond dissociation energy (BDE). The comparison of BDE suggests that rupturing the C-C bond is the trigger for thermolysis of PNNPs. The computed BDE for cleavage of C-C bond (88.5 kJ/mol) further demonstrates that only the hexa-nitrotriprismane can be considered to be the target of HEDMs.

The waste fluorgypsum was modified and applied as a cement retarder. The main chemical composition and mineral structure of the waste fluorgypsum were analyzed. Scanning electron microscopy (SEM) and eight-channel micro-calorimeter (TAM Air) were employed to analyze the changes in morphology and study the application performance of the modified fluorgypsum, respectively. Experimental results indicate that the flexural strength and compressive strength of the modified fluorgypsum are roughly equal to those of the natural gypsum. The morphology of the crystal of the fluorgypsum changes from block particle into trimetric short column. The fluorgypsum crystals stagger mutually and improve the strength of the hardened body. The modified fluorgypsum as cement retarder could delay the hydration, reduce the heat of the hydration and make the setting time, volume stability, and the SO3 content of the cement meet the national standards. The modified fluorgypsum is a good substitute for the natural gypsum.

Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution digestion and determination of seven kinds of heavy metals including Hg, Se, Sn, Pb, Cd, Ni and Cr was performed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The ICP-AES method was established with good precision and accuracy, relative standard deviation (n=6) was between 2.9% and 5.9%, and the recovery was in the range of 95.0%–104.2%. Concentration of six heavy metals increases in some extent in blood and urine after period of smoking and the increasing of heavy metals in blood and urine all shows time dependence. Significantly higher heavy metal levels are observed in the blood and urine of the cigarette inhaling rabbits in the exposed group. The concentration of six kinds of heavy metals in the blood of the rabbit increases after 16 weeks exposing to cigarette smoking. Three times of Hg, ten times of Se and trace amount of Pb, Cd, Ni and Cr are detected in the blood after 16 weeks of smoking. For urine samples, about three times of Hg, two times of Se, five times of Pb and trace amount of Cd are detected after 16 weeks of inhalation of cigarette. Comparatively, higher concentration of heavy metals are detected after inhaling of Nise cigarette.

Based on the pipe transportation of paste-like backfilling system of a certain deep coal mine, its dynamics process was simulated and analyzed. A two-dimensional dynamic model of extraordinary deep and lone pipe was built by GAMBIT, on the basis of which the simulation was done by implicit solver of FLUENT 2ddp. The results show that hydraulic loss of pipe transportation is less than the pressure produced by gravity, which means the backfilling material can flow by itself. When the inlet velocity is 3.2 m/s, the maximum velocity of 4.10 m/s is at the elbow and the maximum velocity in the horizontal pipe is 3.91 m/s, which can both meet the stability requirement. The results of the simulation are proved to be reliable by the residual monitor plotting of related parameter, so it can be concluded that the system of pipe transportation is safe.

The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticated in production. The experimental result shows that with different samples and leaching systems, the adaptability and Cl⁻ tolerance of bacteria are different, and that appropriate chloride ion concentration is conductive to bacterial oxidation, while higher chloride ion concentration will inhibit the bacterial activity and affect the pre-oxidation performance. Under the present production conditions, TCJ can adapt to the changes of water quality in the source of water and its critical chloride ion tolerance value is 2.7 g/L.

A strain HB-03 to produce alkaline extracellular lipase was isolated from oil-rich soil samples and identified as Aspergillus awamori. The growth conditions and nutritional factors for lipase production by strain HB-03 were optimized, and the maximum lipase production of (45.9±2.3) U/mL was obtained at 30 °C and pH 7.0 after 36 h using olive oil (1%) and sucrose (0.5%) as carbon sources and combination of peptone (2%), yeast extract (0.5%) and ammonium sulfate (0.1%) as nitrogen sources. The lipase was purified to homogeneity with 10.6-fold, 18.84% yield and a specific activity of 1 862.2 U/mg using ammonium sulfate precipitation followed by SephadexG-75 gel filtration chromatography. The purified lipase with molecular mass of 68 ku was estimated by SDS-PAGE. The optimum pH and temperature for the purified lipase were found to be 8.5 and 40 °C, respectively. The lipase kept more than 80% of activity in pH 7.0–10.0 and temperatures up to 45 °C. The metal ions of Mn²⁺, Ba²⁺ significantly enhanced the lipase activity, whereas Cu²⁺, Fe³⁺ and Mg²⁺ strongly reduced the lipase activity. The K_m and V_max values of the purified enzyme for p-nitrophenyl palmitate were 0.13 mmol/L and 60.6 mmol/(L·min), respectively. The results show that this novel lipase has potential industrial applications.

Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute transport within the leaching system. The governing equations are solved numerically using the COMSOL Multiphysics software for the coupled reactive flow and solute transport at micro-scale, meso-scale and macro-scale levels. At or near the surface of ore particle, the acid concentration is relatively higher than that in the central area, while the concentration gradient decreases after 72 d of leaching. The flow simulation between ore particles by combining X-ray CT technology shows that the highest velocity in narrow pore reaches 0.375 m/s. The air velocity within the dump shows that the velocity near the top and side surface is relatively high, which leads to the high oxygen concentration in that area. The coupled heat transfer and liquid flow process shows that the solution can act as an effective remover from the heap, dropping the highest temperature from 60 to 38 °C. The reagent transfer coupled with solution flow is also analyzed. The results obtained allow us to obtain a better understanding of the fundamental physical phenomenon of the bioleaching process.

In the non-linear microwave drying process, the incremental improved back-propagation (BP) neural network and response surface methodology (RSM) were used to build a predictive model of the combined effects of independent variables (the microwave power, the acting time and the rotational frequency) for microwave drying of selenium-rich slag. The optimum operating conditions obtained from the quadratic form of the RSM are: the microwave power of 14.97 kW, the acting time of 89.58 min, the rotational frequency of 10.94 Hz, and the temperature of 136.407 °C. The relative dehydration rate of 97.1895% is obtained. Under the optimum operating conditions, the incremental improved BP neural network prediction model can predict the drying process results and different effects on the results of the independent variables. The verification experiments demonstrate the prediction accuracy of the network, and the mean squared error is 0.16. The optimized results indicate that RSM can optimize the experimental conditions within much more broad range by considering the combination of factors and the neural network model can predict the results effectively and provide the theoretical guidance for the follow-up production process.

Garlic peel, as the raw material, was modified by loading with zirconium(IV), exhibiting quite good uptaking behaviour for fluoride anion. The adsorption experiments were carried out in batch shaking vessels, and the process was strongly dependent on the pH value. The adsorption fits Langmuir model well, and the maximum adsorption capacities at equilibrium pH 2 and 6 are evaluated to be 1.10 and 0.89 mol(fluoride)/kg of Zr-loaded garlic peel gel, respectively. The evaluation of effects of coexisting anions such as nitrate, sulfate and phosphate shows that nitrate and sulfate have no negative effect on the adsorption of fluoride, while phosphate has a little effect. Adsorption kinetics of fluoride is well described by pseudo-second-order rate equation, and the corresponding adsorption rate constant is calculated to be 3.25×10⁻³ g/(mg·min).

The sideward permafrost along the Qinghai-Tibet Highway (QTH) contains massive ground-ice and is at a relatively high temperature. Under the influence of the steady increase of human activities, the permafrost environment has been changed greatly for a long time. At present, the permafrost becomes warm and rapidly degenerates, including the decline of the permafrost table, rising of the ground temperature, shortening of the length of frozen section, and extension of range of melting region. Some thaw hazards (e.g. thaw slumping and thermokarst pond) have widely occurred along both sides of the roadbed. In addition, due to the incomplete construction management, the vegetation adjacent to the highway is seriously damaged or eradicated, resulting in the land desertification and ecosystem out of balance. The dust, waste and garbage brought by drivers, passengers, maintenance workers, and transportations may also pollute the permafrost environment.

Using soil data of the Second National Field Survey, the soil fertility of wetland ecosystem of Dongting Lake was evaluated by using the technology of GIS and method of fuzzy evaluation. Integrated with the wetland actuality of Dongting Lake and particularity of paddy, seven factors (including soil organic matter, total nitrogen, total phosphorus, total potassium, available phosphorus, available potassium, and pH value), closely related with soil fertility, were chosen to establish the index system of synthetical evaluation. Based on the effect degree of each selected index on soil fertility, a judgment matrix was built, and the weight coefficient was determined by the method of correlation coefficient. Finally, under the support of the spatial analysis module of GIS (Geographic Information System), the spatial distribution properties of soil fertility in wetland ecosystem of Dongting Lake were studied. The results show that the soil fertility of Dongting Lake wetland ecosystem is not very good, and the area of type III and type IV achieves 69.8%. As a result, many countermeasures should be taken to improve the soil fertility. As for the spatial properties, the soil fertility level of central and west Dongting Lake is much higher than that of north and south part. The soil fertility of paddy field surpasses that of red soil, and the contents of soil organic matter and total nitrogen in paddy field are large.

The problem of simultaneous scheduling of machines and vehicles in flexible manufacturing system (FMS) was addressed. A spreadsheet based genetic algorithm (GA) approach was presented to solve the problem. A domain independent general purpose GA was used, which was an add-in to the spreadsheet software. An adaptation of the propritary GA software was demonstrated to the problem of minimizing the total completion time or makespan for simultaneous scheduling of machines and vehicles in flexible manufacturing systems. Computational results are presented for a benchmark with 82 test problems, which have been constructed by other researchers. The achieved results are comparable to the previous approaches. The proposed approach can be also applied to other problems or objective functions without changing the GA routine or the spreadsheet model.

The hydraulic roll-bending device was studied, which was widely used in modern cold rolling mills to regulate the strip flatness. The loaded roll gap crown mathematic model and the strip crown mathematic model of the reversing cold rolling process were established, and the deformation model of roll stack system of the 6-high 1 250 mm high crown (HC) reversing cold rolling mill was built by slit beam method. The simulation results show that, the quadratic component of strip crown decreases nearly linearly with the increase of the work roll bending force, when the shifting value of intermediate roll is determined by the rolling process. From the first pass to the fifth pass of reversing rolling process, the crown controllability of bending force is gradually weakened. Base on analyzing the relationship among the main factors associated with roll-bending force in reversing multi-pass rolling, such as strip width and rolling force, a preset mathematic model of bending force is developed by genetic algorithm. The simulation data demonstrate that the relative deviation of flatness criterions in each rolling pass is improved significantly and the mean relative deviation of all five passes is decreased from 25.1% to 1.7%. The model can keep good shape in multi-pass reversing cold rolling process with the high prediction accuracy and can be used to guide the production process.

In order to support the functional design and simulation and the final fabrication processes for functional surfaces, it is necessary to obtain a multi-scale modelling approach representing both macro geometry and micro details of the surface in one unified model. Based on the fractal geometry theory, a synthesized model is proposed by mathematically combining Weierstrass-Mandelbrot fractal function in micro space and freeform CAGD model in macro space. Key issues of the synthesis, such as algorithms for fractal interpolation of freeform profiles, and visualization optimization for fractal details, are addressed. A prototype of the integration solution is developed based on the platform of AutoCAD’s Object ARX, and a few multi-scale modelling examples are used as case studies. With the consistent mathematic model, multi-scale surface geometries can be represented precisely. Moreover, the visualization result of the functional surfaces shows that the visualization optimization strategies developed are efficient.

To address the issue of premature convergence and slow convergence rate in three-dimensional (3D) route planning of unmanned aerial vehicle (UAV) low-altitude penetration, a novel route planning method was proposed. First and foremost, a coevolutionary multi-agent genetic algorithm (CE-MAGA) was formed by introducing coevolutionary mechanism to multi-agent genetic algorithm (MAGA), an efficient global optimization algorithm. A dynamic route representation form was also adopted to improve the flight route accuracy. Moreover, an efficient constraint handling method was used to simplify the treatment of multi-constraint and reduce the time-cost of planning computation. Simulation and corresponding analysis show that the planning results of CE-MAGA have better performance on terrain following, terrain avoidance, threat avoidance (TF/TA²) and lower route costs than other existing algorithms. In addition, feasible flight routes can be acquired within 2 s, and the convergence rate of the whole evolutionary process is very fast.

The closed loop control model was built up for compensating the springback and enhancing the work piece precision. A coupled closed loop algorithm and a finite element method were developed to simulate and correct the springback of incremental sheet forming. A three-dimensional finite element model was established for simulation of springback in incremental sheet forming process. The closed loop algorithm of trajectory profile for the incremental sheet forming based on the wavelet transform combined with fast Fourier transform was constructed. The profile of processing tool path of shallow dishing with spherical surface was designed on the basis of the profile correction algorithm. The result shows that the algorithm can predict an ideal profile of processing track, and the springback error of incremental sheet forming is eliminated effectively. It has good convergence efficiency, and can improve the workpiece dimensional accuracy greatly.

To research the loading characteristic of rocks with different structures cut by helical cutting mechanism (HCM), three different structures of rock (hard-soft-hard rock, soft-hard rock and soft-hard-soft rock) were built. And each type model was further divided into three types when the experiments were carried out. To reduce the errors of cutting load caused by manually configured rock in each test, the cutting load of soft rock was taken as a benchmark, and the differences of the cutting load of the different structures of rocks and the soft rock were used to reflect the cutting load change rules of the HCM. The results indicate that, the cutting load of only the HCM top cutting hard rock is larger than that of only the HCM bottom cutting hard rock for dextral HCM, and the cutting load fluctuation is larger, too. However, when the top and the bottom of the HCM cutting hard rock simultaneously, its cutting load is the largest, but the cutting load fluctuation is the least. And the HCM cutting load increment is increased linearly with the increase of rock compressive strength. The HCM cutting load increment is increased exponentially with the increase of hard rock cutting thickness.

In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications, a battery model with a moderate complexity was established. The battery open circuit voltage (OCV) as a function of state of charge (SOC) was depicted by the Nernst equation. An equivalent circuit network was adopted to describe the polarization effect of the lithium-ion battery. A linear identifiable formulation of the battery model was derived by discretizing the frequent-domain description of the battery model. The recursive least square algorithm with forgetting was applied to implement the on-line parameter calibration. The validation results show that the on-line calibrated model can accurately predict the dynamic voltage behavior of the lithium-ion battery. The maximum and mean relative errors are 1.666% and 0.01%, respectively, in a hybrid pulse test, while 1.933% and 0.062%, respectively, in a transient power test. The on-line parameter calibration method thereby can ensure that the model possesses an acceptable robustness to varied battery loading profiles.

A novel distributed cognitive radio multichannel medium access protocol without common control channel was proposed. The protocol divided a transmission interval into two parts for exchanging control information and data, respectively. In addition to evaluating system saturation throughput of the proposed protocol, a three-dimensional multi channel Markov chain model to describe the sate of the cognitive users (CUs) in dynamic spectrum access was presented. The proposed analysis was applied to the packet transmission schemes employed by the basic, RTS/CTS access mechanism adopted in the normal IEEE 802.11. Analyzing the advantage of the two methods, a hybrid access mechanism was proposed to improve the system throughput. The simulation results show that the experiment results are close to the value computed by the model (less than 5%), and the proposed protocol significantly improves the performance of the system throughput by borrowing the licensed spectrum. By analyzing the dependence of throughput on system parameters, hybrid mechanism dynamically selecting access mechanism can maintain high throughput.

In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethernet, system architecture, time characteristic parameters of control-loop etc, a performance analysis model for real-time Ethernet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development.

The synchronous tracking control problem of a hydraulic parallel manipulator with six degrees of freedom (DOF) is complicated since the inclusion of hydraulic elements increases the order of the system. To solve this problem, cascade control method with an inner/outer-loop control structure is used, which masks the hydraulic dynamics with the inner-loop so that the designed controller takes into account of both the mechanical dynamics and the hydraulic dynamics of the manipulator. Furthermore, a cross-coupling control approach is introduced to the synchronous tracking control of the manipulator. The position synchronization error is developed by considering motion synchronization between each actuator joint and its adjacent ones based on the synchronous goal. Then, with the feedback of both position error and synchronization error, the tracking is proven to guarantee that both the position errors and synchronization errors asymptotically converge to zero. Moreover, the effectiveness of the proposed approach is verified by the experimental results performed with a 6-DOF hydraulic parallel manipulator.

A novel immune algorithm suitable for dynamic environments (AIDE) was proposed based on a biological immune response principle. The dynamic process of artificial immune response with operators such as immune cloning, multi-scale variation and gradient-based diversity was modeled. Because the immune cloning operator was derived from a stimulation and suppression effect between antibodies and antigens, a sigmoid model that can clearly describe clonal proliferation was proposed. In addition, with the introduction of multiple populations and multi-scale variation, the algorithm can well maintain the population diversity during the dynamic searching process. Unlike traditional artificial immune algorithms, which require randomly generated cells added to the current population to explore its fitness landscape, AIDE uses a gradient-based diversity operator to speed up the optimization in the dynamic environments. Several reported algorithms were compared with AIDE by using Moving Peaks Benchmarks. Preliminary experiments show that AIDE can maintain high population diversity during the search process, simultaneously can speed up the optimization. Thus, AIDE is useful for the optimization of dynamic environments.

CMOS active mixer based on voltage control load technique which can operate at 1.0 V supply voltage was proposed, and its operation principle, noise and linearity analysis were also presented. Contrary to the conventional Gilbert-type mixer which is based on RF current-commutating, the load impedance in this proposed mixer is controlled by the LO signal, and it has only two stacked transistors at each branch which is suitable for low voltage applications. The mixer was designed and fabricated in 0.18 μm CMOS process for 2.4 GHz ISM band applications. With an input of 2.44 GHz RF signal and 2.442 GHz LO signal, the measurement specifications of the proposed mixer are: the conversion gain (G_C) is 5.3 dB, the input-referred third-order intercept point (P_IIP3) is 4.6 dBm, the input-referred 1 dB compression point (P_1dB) is −7.4 dBm, and the single-sideband noise figure (N_FSSB) is 21.7 dB.

novel technique for the optimal tuning of power system stabilizer (PSS) was proposed, by integrating the modified particle swarm optimization (MPSO) with the chaos (MPSOC). Firstly, a modification in the particle swarm optimization (PSO) was made by introducing passive congregation (PC). It helps each swarm member in receiving a multitude of information from other members and thus decreases the possibility of a failed attempt at detection or a meaningless search. Secondly, the MPSO and chaos were hybridized (MPSOC) to improve the global searching capability and prevent the premature convergence due to local minima. The robustness of the proposed PSS tuning technique was verified on a multi-machine power system under different operating conditions. The performance of the proposed MPSOC was compared to the MPSO, PSO and GA through eigenvalue analysis, nonlinear time-domain simulation and statistical tests. Eigenvalue analysis shows acceptable damping of the low-frequency modes and time domain simulations also show that the oscillations of synchronous machines can be rapidly damped for power systems with the proposed PSSs. The results show that the presented algorithm has a faster convergence rate with higher degree of accuracy than the GA, PSO and MPSO.

A multi-domain nonlinear dynamic model of a proportional solenoid valve was presented. The electro-magnetic, mechanical and fluid subsystems of the valve were investigated, including their interactions. Governing equations of the valve were derived in the form of nonlinear state equations. By comparing the simulated and measured data, the simulation model is validated with a deviation less than 15%, which can be used for the structural design and control algorithm optimization of proportional solenoid valves.

Perceptual auditory filter banks such as Bark-scale filter bank are widely used as front-end processing in speech recognition systems. However, the problem of the design of optimized filter banks that provide higher accuracy in recognition tasks is still open. Owing to spectral analysis in feature extraction, an adaptive bands filter bank (ABFB) is presented. The design adopts flexible bandwidths and center frequencies for the frequency responses of the filters and utilizes genetic algorithm (GA) to optimize the design parameters. The optimization process is realized by combining the front-end filter bank with the back-end recognition network in the performance evaluation loop. The deployment of ABFB together with zero-crossing peak amplitude (ZCPA) feature as a front process for radial basis function (RBF) system shows significant improvement in robustness compared with the Bark-scale filter bank. In ABFB, several sub-bands are still more concentrated toward lower frequency but their exact locations are determined by the performance rather than the perceptual criteria. For the ease of optimization, only symmetrical bands are considered here, which still provide satisfactory results.

The similarity computations for fuzzy membership function pairs were carried out. Fuzzy number related knowledge was introduced, and conventional similarity was compared with distance based similarity measure. The usefulness of the proposed similarity measure was verified. The results show that the proposed similarity measure could be applied to ordinary fuzzy membership functions, though it was not easy to design. Through conventional results on the calculation of similarity for fuzzy membership pair, fuzzy membership-crisp pair and crisp-crisp pair were carried out. The proposed distance based similarity measure represented rational performance with the heuristic point of view. Furthermore, troublesome in fuzzy number based similarity measure for abnormal universe of discourse case was discussed. Finally, the similarity measure computation for various membership function pairs was discussed with other conventional results.

Based on the measurement model of inverse synthetic aperture radar (ISAR) within a small aspect sector, an imaging method was presented with the application of sparse signal processing. This method can form higher resolution inverse synthetic aperture radar images from compensating incomplete measured data, and improves the clarity of the images and makes the feature structure much more clear, which is helpful for target recognition. The simulation results indicate that this method can provide clear ISAR images with high contrast under complex motion case.

A model of correcting the nonlinear error of photoelectric displacement sensor was established based on the least square support vector machine. The parameters of the correcting nonlinear model, such as penalty factor and kernel parameter, were optimized by chaos genetic algorithm. And the nonlinear correction of photoelectric displacement sensor based on least square support vector machine was applied. The application results reveal that error of photoelectric displacement sensor is less than 1.5%, which is rather satisfactory for nonlinear correction of photoelectric displacement sensor.

The particle image velocimetry (PIV) method was used to investigate the full-field displacements and strains of the limestone specimen under external loads from the video images captured during the laboratory tests. The original colorful video images and experimental data were obtained from the uniaxial compression test of a limestone. To eliminate perspective errors and lens distortion, the camera was placed normal to the rock specimen exposure. After converted into a readable format of frame images, these videos were transformed into the responding grayscale images, and the frame images were then extracted. The full-field displacement field was obtained by using the PIV technique, and interpolated in the sub-pixel locations. The displacement was measured in the plane of the image and inferred from two consecutive images. The local displacement vectors were calculated for small sub-windows of the images by means of cross-correlation. The video images were interrogated in a multi-pass way, starting off with 64×64 images, ending with 16×16 images after 6 iterations, and using 75% overlap of the sub-windows. In order to remove spurious vectors, the displacements were filtered using four filters: signal-to-noise ratio filter, peak height filter, global filter and local filter. The cubic interpolation was utilized if the displacements without a number were encountered. The full-field strain was then obtained using the local least square method from the discrete displacements. The strain change with time at different locations was also investigated. It is found that the normal strains are dependant on the locations and the crack distributions. Between 1.0 and 5.0 s prior to the specimen failure, normal strains increase rapidly at many locations, while a stable status appears at some locations. When the specimen is in a failure status, a large rotation occurs and it increases in the inverse direction. The strain concentration bands do not completely develop into the large cracks, and meso-cracks are not visible in some bands. The techniques presented here may improve the traditional measurement of the strain field, and may provide a lot of valuable information in investigating the deformation/failure mechanism of rock materials.

A numerical procedure for reliability analysis of earth slope based on advanced first-order second-moment method is presented, while soil properties and pore water pressure may be considered as random variables. The factor of safety and performance function is formulated utilizing a new approach of the Morgenstern and Price method. To evaluate the minimum reliability index defined by Hasofer and Lind and corresponding critical probabilistic slip surface, a hybrid algorithm combining chaotic particle swarm optimization and harmony search algorithm called CPSOHS is presented. The comparison of the results of the presented method, standard particle swarm optimization, and selected other methods employed in previous studies demonstrates the superior successful functioning of the new method by evaluating lower values of reliability index and factor of safety. Moreover, the presented procedure is applied for sensitivity analysis and the obtained results show the influence of soil strength parameters and probability distribution types of random variables on the reliability index of slopes.

The field tests were carried out to examine the reinforcement effect of a geogrid on various conditions of embankment height, the number of passages of vibratory roller, the number of reinforced layer of geogrid, and soil properties. The test results of the dynamic earth pressure indicate that the soil reinforced by geogrid is very effective to increase the stiffness of soil, especially in soft soil. The dynamic earth pressure ratio, which is defined as the ratio of dynamic earth pressure to self weight of soils, exponentially decreases as the embankment height increases. The dynamic earth pressure ratio increases up to 80% for soft soils reinforced by both one layer of geogrid in place of no reinforced soils and two layers in place of a single layer of geogrid.

Rare earth element (REE) concentrations were measured by ICP-MS for groundwater collected from deep seated Taiyuan Fm limestone aquifer (from −400 to −530 m) in Renlou Coal Mine, northern Anhui Province, China. It can be concluded that the groundwater is warm (34.0–37.2 °C) Cl-Ca, Na type water with circum-neutral pH (7.35–8.28) and high total dissolved solids (TDS, 1 746–2 849 mg/L). The groundwater exhibits heavy REEs enrichment relative to light REEs compared with Post Archean Average Shale (PAAS), as well as their aquifer rocks (limestone). The enrichment of REEs is considered to be controlled by terrigeneous materials (e.g. zircon) in aquifer rocks, whereas the fractionation of REEs is controlled by marine derived materials (e.g. calcite), to a less extent, terrigeneous materials and inorganic complexation. The Ce anomalies normalized to PAAS and aquifer rocks are weak, which probably reflects the signature of the aquifer rock rather than redox conditions or pH. The similarities of REE patterns between groundwater and aquifer rocks imply that aquifer rocks play important roles in controlling the REE characteristics of groundwater, and then provide a probability for discrimination of groundwater sources by using REEs.

Existing analytical methods of buried steel pipelines subjected to active strike-slip faults depended on a number of simplifications. To study the failure mechanism more accurately, a refined strain analytical methodology was proposed, taking the nonlinear characteristics of soil-pipeline interaction and pipe steel into account. Based on the elastic-beam and beam-on-elastic-foundation theories, the position of pipe potential destruction and the strain and deformation distributions along the pipeline were derived. Compared with existing analytical methods and three-dimensional nonlinear finite element analysis, the maximum axial total strains of pipe from the analytical methodology presented are in good agreement with the finite element results at small and intermediate fault movements and become gradually more conservative at large fault displacements. The position of pipe potential failure and the deformation distribution along the pipeline are fairly consistent with the finite element results.

A true triaxial apparatus which is composed of three units was presented. The apparatus allows for investigations on deformation and seepage behaviors of a single rock fracture subjected to lateral stress and normal stress. The first unit has three jacks which can apply loads independently in three orthogonal directions. The second unit is used to supply water inflow, control seepage pressure and measure flow velocity in real time. The third unit is for measuring the normal deformation of rock fractures. Some tests for investigating the normal deformation and seepage behaviors of rock fractures subjected to normal and lateral loads on hard granite specimens with an artificial persistent fracture, were introduced. The results show that both the normal deformation and the hydraulic conductivity are influenced not only by the normal stress but also by the lateral stress. It is also shown that the aperture and the hydraulic conductivity decrease with the increasing normal stress but increase with the increasing lateral stress and both the aperture and the hydraulic conductivity obey exponential relationships with the normal stress and the lateral stress.

The influence of different features of natural soft clays, namely anisotropy, destructuration and viscosity, on modelling the time-dependent behaviour of Murro embankment was investigated. The newly developed elasto-viscoplastic models were enhanced for determining viscosity parameters in a straightforward way and adopted for the finite element analysis. The same set of common parameters determined from conventional triaxial and oedometer tests was employed for all models, with additional parameters required for representing different soil features. The finite element predictions by using models coupled with BIOT’s consolidation theory were compared with each other and with field data for settlement, horizontal displacement and excess pore pressures. In addition, the stress paths under the embankment loading were also compared with each other to improve the understanding of the effect of different soil features. All simulations demonstrate that all three features significantly influence the predictions. As a consequence, accounting for soil features needs to be carefully considered when they are applied to a construction site.

The impact properties of normal concrete (NC) and reinforced concrete (RC) specimens, steel fibre reinforced concrete (SFRC) specimens and RC+SFRC specimens with different steel fibre dosages were investigated with the drop-weight impact test recommended by ACI Committee 544. The results indicate that the number of blows to final failure is greatly increased by addition of steel fibres. Moreover, the combination of steel fibres and steel rebars demonstrates a significant positive composite effect on the impact resistance, which results in the improvement in impact toughness of concrete specimens. In the view of variation of impact test results, the two-parameter Weibull distribution was adopted to analyze the experimental data. It is proved that the probabilistic distributions of the blows to first crack and to final failure of six types of samples approximately follow two-parameter Weibull distribution.

With consideration of the differences between concrete and steel, three solutions using genetic evolutionary structural optimization algorithm were presented to automatically develop optimal strut-and-tie model for deep beams. In the finite element analysis of the first method, the concrete and steel rebar are modeled by a plane element and a bar element, respectively. In the second method, the concrete and steel are assigned to two different plane elements, whereas in the third method only one kind of plane element is used with no consideration of the differences of the two materials. A simply supported beam under two point loads was presented as an example to verify the validity of the three proposed methods. The results indicate that all the three methods can generate optimal strut-and-tie models and the third algorithm has powerful capability in searching more optimal results with less computational effort. The effectiveness of the proposed algorithm III has also been demonstrated by other two examples.