ZrO₂-mullite nano-ceramics were fabricated by in-situ controlled crystallizing from SiO₂-Al₂O₃-ZrO₂ amorphous bulk. The thermal transformation sequences of the SiO₂-Al₂O₃-ZrO₂ amorphous bulk were investigated by X-ray diffraction, infrared spectrum, scanning electron microscope and differential scanning calorimetric. And the mechanical properties of the nano-ceramics were studied. The results show that the bulks are still in amorphous state at 900 °C and the t-ZrO₂ forms at about 950 °C with a faint spinel-like phase which changes into mullite on further heating. ZrO₂ and mullite become major phases at 1 100 °C and an amount of m-ZrO₂ occur at the same time. The sample heated at 950 °C for 2 h and then at 1 100 °C for 1 h shows very dense and homogenous microstructure with ball-like grains in size of 20–50 nm. With the increase of crystallization temperature up to 1 350 °C, the grains grow quickly and some grow into lath-shaped grains with major diameter of 5 μm. After two-step treatment the highest micro-hardness, flexural strength and fracture toughness of the samples are 13.72 GPa, 520 MPa and 5.13 MPa·m^1/2, respectively.

The ratio of Fe-Al compound at the bonding interface of solid steel plate to Al-7graphite slurry was used to characterize the interfacial structure of steel-Al-7graphite semi-solid bonding plate quantitatively. The relationship between the ratio of Fe-Al compound at interface and bonding parameters (such as preheat temperature of steel plate, solid fraction of Al-7graphite slurry and rolling speed) was established by artificial neural networks perfectly. The results show that when the bonding parameters are 516 °C for preheat temperature of steel plate, 32.5% for solid fraction of Al-7graphite slurry and 12 mm/s for rolling speed, the reasonable ratio of Fe-Al compound corresponding to the largest interfacial shear strength of bonding plate is obtained to be 70.1%. This reasonable ratio of Fe-Al compound is a quantitative criterion of interfacial embrittlement, namely, when the ratio of Fe-Al compound at interface is larger than 70.1%, interfacial embrittlement will occur.

The ablation properties of C/C composites with four different needled preforms prepared by isothermal chemical vapor infiltration (ICVI), which are super-thin mat lay-up, 0°/90° weftless fabric lay-up, 0°/45° weftless fabric lay-up and 0°/45° twill fabric lay-up, were quantitatively evaluated by performing the ablation tests with an engine torch. And their ablation discrepancies were analyzed according to the surface characteristic, porosity and thermal diffusivity. The results show that the 0°/45° weftless composite has a flat eroded surface with no obvious macroscopic pits. Its thickness and mass erosion rates are decreased by about 46.8% and 34.8%, 25.0% and 27.5%, and 17.5% and 19.4% compared with those of the mat, the 0°/90° weftless and the 0°/45° twill composites, respectively. The ablation properties are mainly controlled by the thermo-chemical effect (oxidation), and a little by the thermo-mechanical effect (mechanical denudation). The needling fiber bundles play an important role in accelerating the ablation process and resulting in the heterogeneous ablation.

Single hit compression tests were performed at 1 223–1 473 K and strain rate of 0.1–10 s⁻¹ to study hot deformation behavior and flow stress model of F40MnV steel. The dependence of the peak stress, initial stress, saturation stress, steady state stress and peak stain on Zener-Hollomon parameter were obtained. The mathematical models of dynamic recrystallization fraction and grain size were also obtained. Based on the tested data, the flow stress model of F40MnV steel was established in dynamic recovery region and dynamic recrystallization region, respectively. The results show that the activation energy for dynamic recrystallization is 278.6 kJ/mol by regression analysis. The flow stress model of F40MnV steel is proved to approximate the tested data and suitable for numerical simulation of hot forging.

In order to investigate the regularity of metal magnetic signals of ferromagnetic materials under the effect of applied load, the static tensile test of Q235 steel and 18CrNiWA steel plate specimens were conducted and metal magnetic memory signals of specimens were measured during the test process. The influencing factors of metal magnetic memory signals and the relationship between axial applied load and signals were analyzed. The fracture and microstructure of the specimens were observed. The results show that the magnetic signals corresponding to the measured points change linearly approximately with increasing axial load. The microstructure of Q235 steel is ferrite and perlite, whereas that of 18CrNiWA steel is bainite and low-carbon martensite. The fracture of these two kinds of specimens is ductile rupture; carbon content of specimen materials and dislocation glide give much contribution to the characteristics of magnetic curves.

The effect of mineral particle size, pulp potential and category of oxidant on pyrite leaching was studied. The results show that a smaller mineral particle size leads to a higher leaching rate of pyrite, and the optimum result with pyrite leaching rate of 2.92% is obtained when mineral particle size is less than 0.037 mm. The pulp potential reflects the leaching process. The increase of pulp potential can improve pyrite leaching. The leaching rate and velocity of pyrite can be enhanced rapidly by adding strong oxidant. The kind and the method of adding oxidant have important effect on the pyrite leaching. Appropriate concentration of Fe³⁺ can enhance pyrite leaching but the precipitation generated by high concentration of ferric ion covers the surface of pyrites and prevents the leaching process. The leaching rate increases with the constant addition of H₂O₂.

The heating and melting mechanisms of the pellets immersed in liquid slag were investigated, and the effect of the pellet heating and the melting conditions were studied. The results show that the dust component in the pellet is melted from the surface and no metallic elements are melted before the dust component, the time for the pellet completely melted is reduced as the iron powder content increases since the metallic iron has high thermal conductivity. These are four stages of heating and melting of pellet in liquid slag, they are the growth and melt of solid slag shell, penetration of liquid slag, dissolving of dust component and melting of reduced metals. The lifetime of the solid slag shell is in the range of 7–16 s and increasing the pre-heating temperature of the pellet and the slag temperature can shorten the slag shell lifetime. The time for the dust component in the pellet to be melted completely is in the range of 20–45 s and increasing the pre-heating temperature, especially in the range of 600–800 °C, can obviously reduce the melting time. A higher slag temperature can also improve the pellet melting and the melting time is reduced by 10–15 s when the slag temperature is increased from 1 450 to 1 550 °C. The pellet with higher content of iron powder is beneficial to the melting by improving the heat conductivity.

The cathodic deposition properties and mechanism of Zn in alkaline zincate solution were studied by electrochemical techniques. The results show that Zn²⁺ exists in the alkaline solution in the form of Zn(OH)₄²⁻. The apparent activation energy of the electrode reaction is 38.93 kJ/mol, which indicates that the discharge of Zn(OH)₄²⁻ on cathode is controlled by electrochemical polarization, and accompanied by a preceding chemical reaction. The diffusion coefficient of Zn(OH)₄²⁻ is 2.452 × 10⁻⁶ cm²/s. Zn(OH)₂ is the species directly discharged on the cathode surface. Based on the above results the mechanism of zinc electroplating in alkaline zincate solution was put forward. The discharged species is Zn(OH)₂ formed from the preceding chemical reaction, which becomes Zn(OH)_ad when gaining one electron, and then gaining the second electron to become Zn. The first electron gaining step is rate determining one.

Based on the commercial CFD software CFX-4.3, two-phase flow of electrolyte in 156 kA drained aluminum reduction cells with a new structure was numerically simulated by multi-fluid model and k-ɛ turbulence model. The results show that the electrolyte flow in the drained cells is more even than in the conventional cells. Corresponding to center point feeding, the electrolyte flow in the drained cells is more advantageous to the release of anode gas, the dissolution and diffusion of alumina, and the gradient reduction of the electrolyte density and temperature. The average velocity of the electrolyte is 8.3 cm/s, and the maximum velocity is 59.5 cm/s. The average and maximum velocities of the gas are 23.2 cm/s and 61.1 cm/s, respectively. The cathode drained slope and anode cathode distance have certain effects on the electrolyte flow.

A polymer electrolyte based on poly(vinylidene) fluoride-hexafluoropropylene was prepared by evaporating the solvent of dimethyl formamide, and non-woven fabric was used to reinforce the mechanical strength of polymer electrolyte and maintain a good interfacial property between the polymer electrolyte and electrodes. Polymer lithium batteries were assembled by using LiCoO₂ as cathode material and lithium foil as anode material. Scanning electron microscopy, alternating current impedance, linear sweep voltammetry and charge-discharge tests were used to study the properties of polymer membrane and polymer Li-ion batteries. The results show that the technics of preparing polymer electrolyte by directly evaporating solvent is simple. The polymer membrane has rich micro-porous structure on both sides and exhibits 280% uptake of electrolyte solution. The electrochemical stability window of this polymer electrolyte is about 5.5 V, and its ionic conductivity at room temperature reaches 0.151 S/m. The polymer lithium battery displays an initial discharge capacity of 138 mA·h/g and discharge plateau of about 3.9 V at 0.2 current rate. After 30 cycles, its loss of discharge capacity is only 2%. When the battery discharges at 0.5 current rate, the voltage plateau is still 3.7 V. The discharge capacities of 0.5 and 1.0 current rates are 96% and 93% of that of 0.1 current rate, respectively.

PAN-based graphite felt (PGF) treated in 98% sulphuric acid for 5 h and then kept at 450 °C for 2 h was evaluated for their electrochemical performance as electrodes of vanadium redox battery (VRB). Structure and characteristic of treated PAN-based graphite felt (TPGF) were determined by means of Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Brunauer-Emmett-Teller surface area analysis and VRB test system. The results show that the acid and heat synergistic effect increase the number of —COOH functional groups on the PGF surface, and the PGF is eroded by sulphuric acid oxidation, resulting in the surface area increases from 0.31 m²/g to 0.45 m²/g. The V(II)/V(III) redox reaction is electrochemically reversible on the TPGF electrode, while the V(IV)/V(V) couple is a quasi reversible process. The diffusion coefficients of the oxidation for V(IV)/V(V) obtained from the scope of peak current I_p vs scan rate v^1/2 is 4.4×10⁻⁵ cm²/s. The improvement of electrochemical activity for the electrode is mainly ascribed to the increase of the number of —COOH groups on the TPGF, which behaves as active sites catalyzing the vanadium species reactions and accelerating electron transfer reaction and oxygen transfer.

The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results show that 38 volatile chemical components of RPR are determined, accounting for 95.21% of total contents of volatile chemical components of RPR. The main volatile chemical components of RPR are (Z, Z)-9,12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxybenzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1] heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.

A series of europium(III) complexes of 2-thienyltrifluoroacetonate (HTTA), terephthalic acid (TPA) and phenanthroline (Phen) were synthesized. The new complexes Eu(TPA)(TTA)Phen and Eu₂(TPA)(TTA)₄Phen₂ were characterized by elemental analysis, IR spectrum, scanning electron microscope and thermal stability analysis. The results show that the thermal stability of the Eu(III) complexes increases in the following order: the mononuclear complex Eu(TTA)₃Phen, the binuclear complex Eu₂(TPA)(TTA)₄Phen₂, the chain polynuclear complex Eu(TPA)(TTA)Phen. And the formation of the binuclear/polynuclear structure of the new complexes appears to be responsible for the enhancement of their thermal and optical stability. In addition, The fluorescence excitation spectra of these new complexes show more broad excitation bands than that of the complex Eu(TTA)₃Phen corresponding to their formation. The enhancement of Eu³⁺ fluorescence in the new complexes can be observed by the addition of Gd³⁺. The bright red luminescent plastics can be obtained when the complex EuGd(TPA)(TTA)₄Phen₂ is added above 0.5% (mass fraction).

The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO₃, NClO₄ and HF. The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material (NIST SRM 1633a). The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode (maximum mass resolution R=9 000). The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.

A new nanocomposite material for construction of glucose biosensor was prepared. The biosensor was formed by entrapping glucose oxidase(Gox) into chitosan/nanoporous ZrO₂/multiwalled carbon nanotubes nanocomposite film. In this biosensing thin film, the multiwalled carbon nanotubes can effectively catalyze hydrogen peroxide and nanoporous ZrO₂ can enhance the stability of the immobilized enzyme. The resulting biosensor provides a very effective matrix for the immobilization of glucose oxidase and exhibits a wide linear response range from 8 μmol/L to 3 mmol/L with a correlation coefficient of 0.994 for the detection of glucose. And the response time and detection limit of the biosensor are determined to be 6 s and 3.5 μmol/L, respectively. Another attractive characteristic is that the biosensor is inexpensive, stable and reliable.

N, N’-bis (salicylidene) ethylenediiminocobalt (Cosalen) was encapsulated into microporous NaY zeolite via the technique of “ship-in-bottle”. The encapsulated complex (Cosalen-NaY) was characterized by Fourier-transform infrared spectrum, ultraviolet-visible spectrum, Brunauer-Emmett-Teller surface areas, X-ray diffraction, thermogravimetry-differential thermal analysis and scanning electron microscope. The reaction of cyclohexane oxidation using oxygen was chosen to investigate the catalytic performance of Cosalen-NaY, and the effects of oxygen pressure, temperature and reaction time were also studied. The results show that Cosalen complex is encapsulated into the supercage of the zeolite and the structure of NaY zeolite remains integrity and the thermal stability of Cosalen is greatly enhanced after encapsulation. Cosalen-NaY shows the better activity in the oxidation of cyclohexane without reductant and solvent. The conversion of cyclohexane is up to 13.4% at 150 °C for 3 h under oxygen pressure of 0.85 MPa, with the higher total selectivity to cyclohexanol, cyclohexanone, cyclohexyl hydroperoxide (CHHP) and acid (79.2%) than the neat complex (55.5%). NaY zeolite carrier maybe contributes to the results. There is no obvious induction period to initiate the reaction; furthermore, the amount of CHHP among the products is small, which indicates that the Cosalen-NaY has the strong ability to accelerate the decomposition of CHHP. Recycling tests show that the hybrid material can be used repeatedly with a negligible loss of active sites.

A neural network model and fuzzy neural network controller was designed to control the inner impedance of a proton exchange membrane fuel cell (PEMFC) stack. A radial basis function (RBF) neural network model was trained by the input-output data of impedance. A fuzzy neural network controller was designed to control the impedance response. The RBF neural network model was used to test the fuzzy neural network controller. The results show that the RBF model output can imitate actual output well, the maximal error is not beyond 20 mΩ, the training time is about 1 s by using 20 neurons, and the mean squared errors is 141.9 mΩ². The impedance of the PEMFC stack is controlled within the optimum range when the load changes, and the adjustive time is about 3 min.

A novel extension diagnosis method was proposed for enhancing the diagnosis ability of the conventional dissolved gas analysis. Based on the extension theory a matter-element model was established for qualitatively and quantitatively describing the fault diagnosis problem of power transformers. The degree of relation based on the dependent functions was employed to determine the nature and the grade of the faults in a transformer system. And the proposed method was verified with the experimental data. The results show that accuracy rate of the diagnosis method exceeds 90% and two kinds of faults can be detected at the same time.

Four optimal approaches of high-order finite-impulse response(FIR) digital filters were developed for designing four types filters using neural network algorithms. The solutions were presented as parallel algorithms to approximate the desired frequency response specification. Therefore, these methods avoid matrix inversion, and make a fast calculation of the filter’s coefficients possible. The convergence theorems of these proposed algorithms were presented and proved to illustrate them stable, and the implementation of these methods was described together with some design guidelines. The simulation results show that the ripples of the designed FIR filters are significantly little in the pass-band and stop-band, and the proposed algorithms are of fast convergence.

Based on Fermat’s principle, two-point ray tracing method was studied in three-dimensional structure. By means of first order Taylor’s incomplete series expansion (i.e. no expansion to the length of the ray), a symmetry block tridiagonal matrix equation set was deduced. Further, the positive definiteness of coefficient matrix was discussed, and the positive definiteness was accurately proved in a mathematical way. It assured that the algorithm was well-posed. Associated with iterative method, the solution to ray tracing can be got through step-by-step linearized iteration of the nonlinear problem. An algorithm of the whole path iterative ray tracing method in three-dimensional velocity structure was obtained. This method shows a clear and simple as well as explicit computation formula, which makes ray tracing computation easily applicable in practice. The correction vector is obtained through finding the solution to the positive definite block tridiagonal equation set, which ensures the method is robust convergence. This study offers a new kind of feasible and efficient ray tracing method for three dimensional seismic migration and tomography. Meanwhile, it also provides the prerequisite guarantee to design a fast algorithm.

Based on the metallogenetic geology conditions, the H, O, C and S isotopic compositions were measured by MAT-251 mass spectrometer, and Pb isotope and Rb-Sr dating were carried with MAT-261 multi-acceptor mass spectrometer. The results show that the δ¹⁸O values of gold-bearing vein quartz from different levels are 1.19%–1.42%. The calculated δ¹⁸O values of ore fluids are 0.55%–0.78%, and δD values are from −8.64% to −6.66%. The calculated values of

by the δ³⁴S_py values in quartz veins display sulfur isotope compositions from −0.053% to +0.413%. Carbon isotope compositions of carbonates are from −0.612% to 0.140%. The mole ratios of ²⁰⁶Pb to ²⁰⁴Pb, ²⁰⁷Pb to ²⁰⁴Pb and ²⁰⁸Pb to ²⁰⁴Pb in auriferous quartz vein are 16.987–17.545, 15.342–15.623, and 38.254–38.744, respectively. The age of the Zhuanghe gold deposit determined by Rb-Sr isochron of the fluid inclusions in quartzes is (143.0±5.8) Ma. These isotopic data suggest that the metallogenetic fluids are generated from magmatic hydrotherm and the origin of ore-forming matters is related to the deep-derived magmatic activities. Meanwhile, the metallogenetic epoch of the Zhuanghe gold deposit is in Yanshanian period.

The response and energy dissipation of rock under stochastic stress waves were analyzed based on dynamic fracture criterion of brittle materials integrating with Fourier transform methods of spectral analysis. When the stochastic stress waves transmit through rocks, the frequency and energy ratio of harmonic components were calculated by analytical and discrete analysis methods. The stress waves in shale, malmstone and liparite were taken as examples to illustrate the proposed analysis methods. The results show the harder the rock, the less absorption of energy, the more the useless elastic waves transmitting through rock, and the narrower the cutoff frequency to fracture rock. When the whole stress energy doubles either by doubling the duration time or by increasing the amplitude of stress wave, ratio of the energy of elastic waves transmitting through rock to the whole stress energy (i.e. energy dissipation ratio) is decreased to 10%–15%. When doubling the duration time, the cutoff frequency to fracture rock remains constant. However, with the increase of the amplitude of stress wave, the cutoff frequency increases accordingly.

The proposed prediction model for estimating the maximum rebound ratio was applied to a field explosion test, Mandai test in Singapore. The estimated possible maximum peak particle velocities(PPVs) were compared with the field records. Three of the four available field-recorded PPVs lie exactly below the estimated possible maximum values as expected, while the fourth available field-recorded PPV lies close to and a bit higher than the estimated maximum possible PPV. The comparison results show that the predicted PPVs from the proposed prediction model for the maximum rebound ratio match the field-recorded PPVs better than those from two empirical formulae. The very good agreement between the estimated and field-recorded values validates the proposed prediction model for estimating PPV in a rock mass with a set of joints due to application of a two dimensional compressional wave at the boundary of a tunnel or a borehole.

Finite element modeling methods of steel-concrete composite structure with overlap slab were investigated. A two-step finite element method was presented. It was applied to analyze an extra long span composite bridge. The conversion of structure system and the mechanical behavior of the bridge were analyzed with two different construction methods. The stresses of steel beams, precast slabs and in-situ-place concrete under the total load were compared. The results show that steel-concrete composite structure with overlap slab has many advantages, the construction method that the top in-situ concrete and the concrete in construction joints are cast respectively is rather reasonable than the one that the top in-situ concrete and the concrete in construction joints are cast at the same time, and the two-step finite element method is affective to such large-scale structures.

To determine the ultimate bearing capacity of foundations on sloping ground surface in practice, energy dissipation method was used to formulate the bearing capacity as programming problem, and full-scale model experiments were investigated to analyze the performance of the soil slopes loaded by a strip footing in laboratory. The soil failure is governed by a linear Mohr-Coulomb yield criterion, and soil deformation follows an associated flow rule. Based on the energy dissipation method of plastic mechanics, a multi-wedge translational failure mechanism was employed to obtain the three bearing capacity factors related to cohesion, equivalent surcharge load and the unit gravity for various slope inclination angles. Numerical results were compared with those of the published solutions using finite element method and those of model experiments. The bearing capacity factors were presented in the form of design charts for practical use in engineering. The results show that limit analysis solutions approximate to those of model tests, and that the energy dissipation method is effective to estimate bearing capacity of soil slope.

Based on the analysis method for tailings dam in upstream raising method presently used in metallurgy and nonferrous metals tailings depository in the world, an effective stress analysis method of seismic response for high tailings dam was developed according to the results of engineering geological exploration, static and dynamic test and stability analysis on Baizhishan tailing dam 113.5 m high. The law of generation, diffusion and dissipation of seismic pore water pressure during and after earthquake was investigated, and the results of tailings dam’s acceleration, seismic dynamic stress and pore water pressure were obtained. The results show that the seismic stability and liquefaction resistance of high tailings dam are strengthened remarkably, and the scope and depth of liquefaction area at the top of dam are reduced greatly. The interior stress is compressive stress, the stress level of every element is less than 1.0 and the safety coefficient of every element is greater than 1.0. The safety coefficient against liquefaction of every element of tailing dam is greater than 1.5 according to the effective stress analysis of seismic response by finite element method. The calculated results prove that liquefaction is the main reason of seismic failure of high tailing dams, and the effect of seismic inertia forces on high tailing dams’ stability during earthquake is secondary reason.

To study the stiffness distribution of girder and the method to identify modal parameters of cable-stayed bridge, a simplified dynamical finite element method model named three beams model was established for the girder with double ribs. Based on the simplified model four stiffness formulae were deduced according to Hamilton principle. These formulae reflect well the contribution of the flexural, shearing, free torsion and restricted torsion deformation, respectively. An identification method about modal parameters was put forward by combining method of peak value and power spectral density according to modal test under ambient excitation. The dynamic finite element method analysis and modal test were carried out in a long-span concrete cable-stayed bridge. The results show that the errors of frequencies between theoretical analysis and test results are less than 10% mostly, and the most important modal parameters for cable-stayed bridge are determined to be the longitudinal floating mode, the first vertical flexural mode and the first torsional mode, which demonstrate that the method of stiffness distribution for three beams model is accurate and method to identify modal parameters is effective under ambient excitation modal test.

To evaluate the credit risk of customers in power market precisely, the new chaotic searching and fuzzy neural network (FNN) hybrid algorithm were proposed. By combining with the chaotic searching, the learning ability of the FNN was markedly enhanced. Customers’ actual credit flaw data of power supply enterprises were collected to carry on the real evaluation, which can be treated as example for the model. The result shows that the proposed method surpasses the traditional statistical models in regard to the precision of forecasting and has a practical value. Compared with the results of ordinary FNN and ANN, the precision of the proposed algorithm can be enhanced by 2.2% and 4.5%, respectively.

In China, economic centers are far from energy storage bases, so it is significant to select a proper energy transferring mode to improve the efficiency of energy usage. To solve this problem, an optimal allocation model based on energy transfer mode was proposed after objective function for optimizing energy using efficiency was established, and then, a new Tabu search and particle swarm hybrid optimizing algorithm was proposed to find solutions. While actual data of energy demand and distribution in China were selected for analysis, the economic critical value in comparison between the long-distance coal transfer and electric power transmission was gained. Based on the above discussion, some proposals were put forward for optimal allocation of energy transfer modes in China. By comparing other three traditional methods that are based on regional price differences, freight rates and annual cost with the proposed method, the result indicates that the economic efficiency of the energy transfer can be enhanced by 3.14%, 5.78% and 6.01%, respectively.