A Thermecmastor-Z hot deformation simulator, optical microscopy, XRD and TEM were employed to characterize the flow stress behavior and microstructure of twin roll cast ZK60 magnesium alloy during initial stage of hot compression at elevated temperature of 300 °C and 400 °C and a given strain rate of 10⁻² s⁻¹. The results suggest that flow stress drop during initial stage of hot compression at 300°C, generally led by dynamic recrystallization, is attributed to twinning, correspondingly to dynamic recrystallization as deformation temperature is raised to 400 °C.

To investigate the feasibility of implanting the biocomposite of calcium phosphate cement (CPC)/polylactic acid-polyglycolic acid (PLGA) into animals for bone defects repairing, the biocomposite of CPC/PLGA was prepared and its setting time, compressive strength, elastic modulus, pH values, phase composition of the samples, degradability and biocompatibility in vitro were tested. The above-mentioned composite implanted with bone marrow stromal cells was used to repair defects of the radius in rabbits. Osteogenesis was histomorphologically observed by using an electron-microscope. The results show that compared with the CPC, the physical and chemical properties of CPC/PLGA composite have some differences in which CPC/PLGA composite has better biological properties. The CPC/PLGA composite combined with seed cells is superior to the control in terms of the amount of new bones formed after CPC/PLGA composite is implanted into the rabbits, as well as the speed of repairing bone defects. The results suggest that the constructed CPC/PLGA composite basically meets the requirements of tissue engineering scaffold materials and that the CPC/PLGA composite implanted with bone marrow stromal cells may be a new artificial bone material for repairing bone defects because it can promote the growth of bone tissues.

Magnetic starch particles (MSPs) were synthesized in water-in-oil microemulsion at room temperature. MSPs were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FTIR), zeta potential system, thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The average diameter of the MSPs was 220 nm, dispersed with well-proportioned size and magnetic resonance, the saturation magnetization was 3.64 A·m²/kg. MSP was coated with poly-L-lysine (PLL), and then the surface of PLL-MSP was combined with fluorescein isothiocynate (FITC). Results show that fluorescent/magnetic starch particles (FMSPs) are of stable photo-bleaching capability compared with free FITC, with low bio-toxicity and certain function of magnetic separation. It is expected that FMSPs are bifunctional nano-materials including fluorescence labelling and magnetic separation.

The Zn(II) phthalocyanine sensitized TiO₂ (ZnPc-TiO₂) nanoparticles were prepared by hydrothermal method via impregnation with ZnPc. The as-prepared photocatalysts were characterized by X-ray diffractometry (XRD) and diffuse reflectance spectroscopy (DRS), and the surface photovoltage spectroscopy (SPS) and photocatalytic degradation of rhodamine B (RhB) were studied under illuminating. The experimental results indicate that TiO₂ sensitized by ZnPc extends its absorption band into the visible region effectively, and the sensitized TiO₂ has higher activity than TiO₂ (Degussa P-25) under the simulated solar light and the visible light. Based on the DRS and SPS results, the mechanism about the photogenerated carrier transfer between TiO₂ and ZnPc is proposed. At a lower ZnPc content (⩽0.20 μmol/g), ZnPc monomer acts as the electron donor, which provides the photoinduced electrons to the conduction band of TiO₂. These photoinduced electrons can transfer to molecular oxygen (O₂), leading to the formation of active species, such as superoxide/hydroxide radicals and singlet oxygen, which is beneficial to the photocatalytic reaction. While at a higher ZnPc content (>0.20 μmol/g), the formation of ZnPc dimer results in the decrease of photocatalytic activities of ZnPc-TiO₂ photocatalyst.

Microarc oxidation (MAO) coatings were prepared on 2024 aluminum alloy in a Na₂SiO₃-KOH electrolyte with KMnO₄ addition varying from 0 to 4 g/L. The microstructure and phases of the coatings were characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD), respectively. The corrosion resistance of MAO coatings was evaluated by electrochemical potentiodynamic polarization in 5% (mass fraction) NaCl solution. The results show that when KMnO₄ is added into base electrolyte, the growth speed of oxide coatings is increased obviously. The main phase of oxide coatings is Al₂O₃, and the contents of MnO₂ and Mn₂AlO₄ phases are increased at the top of oxide coatings with increasing the concentration of KMnO₄. The solute elements participate in forming the oxide coatings. When a proper concentration of KMnO₄ (2.5 g/L) is added into the base solution, the micropores of the MAO coatings are small and compact, and the corrosion resistance of oxide coatings is increased largely.

The radiative properties of three different materials surfaces with one-dimensional microscale random roughness were obtained with the finite difference time domain method (FDTD) and near-to-far-field transformation. The surface height conforms to the Gaussian probability density function distribution. Various computational modeling issues that affect the accuracy of the predicted properties were discussed. The results show that, for perfect electric conductor (PEC) surfaces, as the surface roughness increases, the magnitude of the spike reduces and eventually the spike disappears, and also as the ratio of root mean square roughness to the surface correlation distance increases, the retroreflection becomes evident. The predicted values of FDTD solutions are in good agreement with the ray tracing and integral equation solutions. The overall trend of bidirectional reflection distribution function (BRDF) of PEC surfaces and silicon surfaces is the same, but the silicon’s is much less than the former’s. The BRDF difference from two polarization modes for the gold surfaces is little for smaller wavelength, but it is much larger for the longer wavelength and the FDTD simulation results agree well with the measured data. In terms of PEC surfaces, as the incident angle increases, the reflectivity becomes more specular.

Deformation behavior of slab at the straightening stage during continuous casting was simulated by the explicit dynamic finite element method, and the stress distribution along the width direction of the slab and its change regularity at slab center during continuous casting were obtained. The influence of distribution and change of stress on the propagation of longitudinal cracks on slab surface was discussed. The results show that the tensional stress appears on slab surface at the inner arc side and the compressive stress appears on slab surface at the outer arc side at stages 6–8 in straightening zone during continuous casting. Longitudinal cracks generally appear on slab top surface and do not appear on slab bottom surface, which are also observed in industry.

A series of Mn-doped TiO₂ nanowires (NWs) were prepared by hydrothermal method at the mole fraction of Mn changing from 0 to 12.0%. X-ray powder diffraction (XRD) analysis shows that all the samples have pure anatase structure. SEM and TEM studies show that the diameter and the length of the Mn-doped TiO₂ NWs are larger than those of the undoped TiO₂ NWs. Energy dispersive X-ray spectroscopy (EDX) reveals that the samples are composed of Ti, Mn and O. According to magnetization measurements, all samples show ferromagnetic behavior, but only the undoped TiO₂ NWs are completely ferromagnetic with a saturated magnetization about 1.0 mA·m²/kg. Mn-doped TiO₂ samples exhibit antiferromagnetic and ferromagnetic (AF-FM) behaviors simultaneously. Photoluminescence (PL) spectra demonstrate the existence of MnO₂ sublattice. These observations indicate that an AF-WF crossover is induced by the coexistence of TiO₂ sublattice and MnO₂ sublattice.

Selection of materials, as an area of design research, has been under considerable interest over the years. Materials selection is one of the most important activities in the product development process. Inappropriate decision of materials can cause the product to be reproduced or remanufactured. To avoid this circumstance, one of the useful tools that can be employed in determining the most appropriate material is analytical hierarchy process (AHP). To illustrate the application of AHP, six different types of composite materials were considered. The most appropriate one for suitability of use in manufacturing automotive bumper beam was determined by considering eight main selection factors and 12 sub-factors. The AHP analysis reveals that the glass fibre epoxy is the most appropriate material because it has the highest value (25.7%, mass fraction) compared with other materials. The final material is obtained by performing six different scenarios of the sensitivity analysis. It is proved that glass fibre epoxy is the most optimum decision.

Bi₂O₃-ZnO-B₂O₃ system glass is a kind of lead-free low melting sealing glasses. The structure of Bi₂O₃-ZnO-B₂O₃ system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with the increase of B₂O₃ content, the transition temperature T_g and softening temperature T_f of Bi₂O₃-ZnO-B₂O₃ system low-melting sealing glasses increase, which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass. With increasing the heat treatment temperature, a large number of liquid phases appear in samples and the sinter efficiency of the samples increases. The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi—O bond from [BO₃] pyramidal and [BiO₆] octahedral units and B—O from [BO₃] and [BO₄] units. With the decrease of B₂O₃ content, the crystallization tendency of the glass increases. In glass samples B₁ and B₂, crystallization starts at 460 °C and 540 °C, respectively. Both of them precipitate Bi₂₄B₂O₃₉ phases.

Invading track of chloride ions and chloride ion distribution rule in cement-based materials were investigated by partially soaking in 3.5% (mass fraction) NaCl solution and fully immerging in 3.5% and 5.0% (mass fraction) NaCl solution, respectively, and relevant invading mechanisms were discussed. Results indicate that under full immerging condition, the invading track of chloride ions in cement mortar is similar to beeline that is vertical to chloride ion invading direction, and chloride ion content decreases rapidly with the increase of chloride ion invading depth. Under partial soaking condition, the invading track of chloride ion in cement mortar is similar to the shape of concave parabola, and chloride ion content decreases slowly along the lengthway direction of cement mortar samples in the distance of 20–80 mm from the bottom. Lots of chloride ions accumulate in cement mortar surface layer under the effect of capillary rise and evaporation and then invade cement mortar by diffusion effect. Under partial soaking condition, cement mortar is distinguished by four areas, i.e., immerging area, wet area, crystallization area and dry area.

Two soluble copolymers of fluorenone and dioctoxylbenzene (PFN) or anthracene (PFNAn) were synthesized through Heck polymerization, and were characterized by gel permeation chromatography (GPC), FT-IR, ¹H-NMR, elemental analysis and thermogravimetric analysis. The polymers possess good solubility in common organic solvents and high thermal stability with the onset decomposition temperature at higher than 410 °C. The photophysical properties of the polymers were investigated in both solutions and spin-coated films. Cyclic voltammetry results revealed that the copolymers possess higher electron affinity and reversible reduction/re-oxidation processes. Their electroluminescent properties were further investigated. PFN and PFNAn show stable and saturated red light emission with high thermal stability and high electron injection ability. This type of conjugated polymers may be promising for the applications as electron acceptors in polymer photovoltaic cells and electron transporting materials.

The adsorption of Ca(II) ions from aqueous solution by chitosan α-ketoglutaric acid (KCTS) and hydroxamated chitosan α-ketoglutaric acid (HKCTS) was studied in a batch adsorption system. The Langmuir and Freundlich adsorption models were applied to describing the equilibrium isotherms, and isotherm constants were determined. The kinetics of the adsorption with respect to the initial Ca(II) ions concentration, temperature and pH was investigated. The pseudo-first-order and second-order kinetic models were used to describe the kinetic data and the rate constants were evaluated. The results show that the experimental data fit well to the Langmuir isotherms with a high correlation coefficient (R²). The pseudo-second-order rate expression provides the best fitting kinetic model. The pseudo second-order kinetic model is indicated with the activation energy of 26.22 kJ/mol and 6.16 kJ/mol for KCTS and HKCTS, respectively. It is suggested that the overall rate of adsorption of Ca(II) ions is likely to be controlled by the chemical process.

The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments, zeta potential measurements and infrared spectrum analysis. Flotation test results indicate that DLZ is the selective collector of chalcopyrite. Especially, the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems, while the recovery of pyrite is less than 10%. When using CaO as pH regulator, at pH=7–11, the floatability of pyrite is depressed and the recovery is less than 5%. Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ, confirming that collector DLZ shows selectivity to chalcopyrite and pyrite. And FTIR results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface.

The mercury sulfidation experiments were conducted in the pH range from 1 to 13. The results show that Hg(II) reacted with equimolar S(II) has the lowest remained Hg(II) concentration (9.7 μg/L) at pH 1.0 and the highest remained concentration (940.8 μg/L) at pH 13.0. Meanwhile, the changes of pH values were monitored exactly, which reveal that solution pH values change when mixing the same pH value solutions of HgCl₂ and Na₂S. In order to explain the phenomena and determine the reaction paths of Hg(II) reacting with S(II) in the solution, the concerned thermodynamics was studied. Species of S(II)-H₂O system and Hg(II)-H₂O system at different pH values were calculated, and then the species distribution diagrams of S(II)-H₂O system, Hg(II)-H₂O system and Hg(II)-Cl⁻-OH⁻-H₂O system were drawn. Combining the experimental data and thermodynamic calculation, the mechanism of Hg(II) reacting with S(II) was deduced. The results indicate that different species of S(II) and Hg(II) have the diverse reaction paths to form HgS precipitate at different pH values and the standard Gibbs free energies change (Δ_rG_m^Θ) of those equations are also calculated, which can provide a guidance for mercury-containing wastewater treatment with Na₂S.

Deep level donor’s ionization behavior of passive film formed on the surface of stainless steel was investigated by Mott-Schottky plots. It is indicated that transformation process of deep level donors’ ionization behavior of passive film on surface of stainless steel can be divided into 4 stages with rising immersion time. At the initial immersion stage (10 min), Fe(II) located in the octahedral sites of the unit cell is not ionized and the deep level does not appear in Mott-Schottky plots. At the second stage (9–38 h), Fe(II) located in the octahedral sites starts to be ionized, which results in deep level donors’ generation and density of deep level donors almost is constant with augmenting immersion time but the thickness of space charge layer is more and more thicker with rising immersion time. At the third stage (48 h–12 d), density of deep level donors rises with increasing immersion time and the thickness of passive films space charge layer decreases. At last stage (above 23 d), both the space charge layer’s thickness and density of deep level donors are no longer changed with increasing immersion time. In the overall immersion stage, the shallow level donors’ density is invariable all the time. The mechanism of deep level donor’s ionization can be the generation of metal vacancies, which results in crystal lattice’s aberration and the aberration energy urges the ionization of Fe(II) in octahedral sites.

A novel heterogeneous catalytic ozonation process in water treatment was studied, with a copper-loaded activated carbon (Cu/AC) that was prepared by an incipient wetness impregnation method at low temperature and tested as a catalyst in the ozonation of phenol and oxalic acid. Cu/AC was characterized using XRD, BET and SEM techniques. Compared with ozonation alone, the presence of Cu/AC in the ozonation processes significantly improves the degradation of phenol or oxalic acid. With the introduction of the hydroxyl radical scavenger, i.e., turt-butanol alcohol (t-BuOH), the degradation efficiency of both phenol and oxalic acid in the Cu/AC catalyzed ozonation process decreases by 22% at 30 min. This indicates that Cu/AC accelerates ozone decomposition into certain concentration of hydroxyl radicals. The amount of Cu(II) produced during the reaction of Cu/AC-catalyzed ozonation of phenol or oxalic acid is very small, which shows that the two processes are both heterogeneous catalytic ozonation reactions.

Support vector regression (SVR) method is a novel type of learning machine algorithms, which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors. This study presents four SVR models by selecting linear, radial basis, spline, and polynomial functions as kernels, respectively for the prediction of urban dust fall levels. The inputs of the models are identified as industrial coal consumption, population density, traffic flow coefficient, and shopping density coefficient. The training and testing results show that the SVR model with radial basis kernel performs better than the other three both in the training and testing processes. In addition, a number of scenario analyses reveal that the most suitable parameters (insensitive loss function ɛ, the parameter to reduce the influence of error C, and discrete level or average distribution of parameters σ) are 0.001, 0.5, and 2 000, respectively.

A new kind of volume control hydraulic press that combines the advantages of both hydraulic and SRM (switched reluctance motor) driving technology is developed. Considering that the serious dead zone and time-variant nonlinearity exist in the volume control electro-hydraulic servo system, the ILC (iterative learning control) method is applied to tracking the displacement curve of the hydraulic press slider. In order to improve the convergence speed and precision of ILC, a fuzzy ILC algorithm that utilizes the fuzzy strategy to adaptively adjust the iterative learning gains is put forward. The simulation and experimental researches are carried out to investigate the convergence speed and precision of the fuzzy ILC for hydraulic press slider position tracking. The results show that the fuzzy ILC can raise the iterative learning speed enormously, and realize the tracking control of slider displacement curve with rapid response speed and high control precision. In experiment, the maximum tracking error 0.02 V is achieved through 12 iterations only.

The dynamic modeling and solution of the 3-RRS spatial parallel manipulators with flexible links were investigated. Firstly, a new model of spatial flexible beam element was proposed, and the dynamic equations of elements and branches of the parallel manipulator were derived. Secondly, according to the kinematic coupling relationship between the moving platform and flexible links, the kinematic constraints of the flexible parallel manipulator were proposed. Thirdly, using the kinematic constraint equations and dynamic model of the moving platform, the overall system dynamic equations of the parallel manipulator were obtained by assembling the dynamic equations of branches. Furthermore, a few commonly used effective solutions of second-order differential equation system with variable coefficients were discussed. Newmark numerical method was used to solve the dynamic equations of the flexible parallel manipulator. Finally, the dynamic responses of the moving platform and driving torques of the 3-RRS parallel mechanism with flexible links were analyzed through numerical simulation. The results provide important information for analysis of dynamic performance, dynamics optimization design, dynamic simulation and control of the 3-RRS flexible parallel manipulator.

A new semi-active suspension control strategy through mixed H₂/H_∞ robust technique was developed due to its flexibility and robustness to model uncertainties. A full car model with seven degrees of freedom was established to demonstrate the effectiveness of the new control approach. Magneto-rheological (MR) dampers were designed, manufactured and characterized as available semi-active actuators in the developed semi-active suspension system. The four independent mixed H₂/H_∞ controllers were devised in order to perform a distributed semi-active control system in the vehicle by which the response velocity and reliability can be improved significantly. The performance of the proposed new approach was investigated in time and frequency domains. A good balance between vehicle’s comfort and road holding was achieved. An effective and practical control strategy for semi-active suspension system was thus obtained. This new approach exhibits some advantages in implementation, performance flexibility and robustness compared to existing methods.

A prediction based energy-efficient target tracking protocol in wireless sensor networks (PET) was proposed for tracking a mobile target in terms of sensing and communication energy consumption. In order to maximize the lifetime of a wireless sensor network (WSN), the volume of messages and the time for neighbor discovery operations were minimized. The target was followed in a special region known as a face obtained by planarization technique in face-aware routing. An election process was conducted to choose a minimal number of appropriate sensors that are the nearest to the target and a wakeup strategy was proposed to wakeup the appropriate sensors in advance to track the target. In addition, a tracking algorithm to track a target step by step was introduced. Performance analysis and simulation results show that the proposed protocol efficiently tracks a target in WSNs and outperforms some existing protocols of target tracking with energy saving under certain ideal situations.

A simplex particle swarm optimization (simplex-PSO) derived from the Nelder-Mead simplex method was proposed to optimize the high dimensionality functions. In simplex-PSO, the velocity term was abandoned and its reference objectives were the best particle and the centroid of all particles except the best particle. The convergence theorems of linear time-varying discrete system proved that simplex-PSO is of consistent asymptotic convergence. In order to reduce the probability of trapping into a local optimal value, an extremum mutation was introduced into simplex-PSO and simplex-PSO-t (simplex-PSO with turbulence) was devised. Several experiments were carried out to verify the validity of simplex-PSO and simplex-PSO-t, and the experimental results confirmed the conclusions: (1) simplex-PSO-t can optimize high-dimension functions with 200-dimensionality; (2) compared PSO with chaos PSO (CPSO), the best optimum index increases by a factor of 1×10²–1×10⁴.

Based on the methods of acquaintance cache and group-based intelligent forwarding of service recommendations, a novel group-based active service (GAS) protocol for migrating workflows was proposed. This protocol did not require service requesters to discover services or resources. The semantic acquaintance knowledge representation was exploited to describe service groups and this semantic information was used to recommend service to respective clients. The experimental results show that the new protocol proposed offers better performance than other protocols in terms of first-response-time, success-scope and ratio of success-packet-number to total-packet-number. When the number of service request packet is 20, the first-response-time of GAS protocol is only 5.1 s, which is significantly lower than that of other protocols. The success-scope of GAS protocol is 49.1%, showing that GAS protocol can effectively improve the reliability of mobile transactions. And the ratio of success-packet-number to total-packet-number of GAS protocol is up to 0.080, which is obviously higher than that of other protocols.

In order to obtain accurate prediction model and compensate for the influence of model mismatch on the control performance of the system and avoid solving nonlinear programming problem, an adaptive fuzzy predictive functional control (AFPFC) scheme for multivariable nonlinear systems was proposed. Firstly, multivariable nonlinear systems were described based on Takagi-Sugeno (T-S) fuzzy models; assuming that the antecedent parameters of T-S models were kept, the consequent parameters were identified on-line by using the weighted recursive least square (WRLS) method. Secondly, the identified T-S models were linearized to be time-varying state space model at each sampling instant. Finally, by using linear predictive control technique the analysis solution of the optimal control law of AFPFC was established. The application results for pH neutralization process show that the absolute error between the identified T-S model output and the process output is smaller than 0.015; the tracking ability of the proposed AFPFC is superior to that of non-AFPFC (NAFPFC) for pH process without disturbances, the overshoot of the effluent pH value of AFPFC with disturbances is decreased by 50% compared with that of NAFPFC; when the process parameters of AFPFC vary with time the integrated absolute error (IAE) performance index still retains to be less than 200 compared with that of NAFPFC.

A two-dimensional (2D) finite element analysis was carried out to assess the time-dependent behavior of single vertical pile embedded in elasto-plastic soil. The finite element analyses were carried out using the linear elastic model for the structure of the pile, while the Mohr-Coulomb model was used for representing the soil behavior surrounding the pile. The study includes cohesionless and cohesive soil to assess the lateral response of pile in the two types of soil. The whole geotechnical model is suitable for problem of piles to determine the design quantities such as lateral deformation, lateral soil stress and its variation with time. The model is verified based on the results of published cases and there is good comparison between the results of published case and the present simulation model. It is found that, the pile in cohesionless soil has more resistance in the rapid loading and less one in the long term loading. On the other hand, the pile in cohesive soil shows opposite behavior.

Large-scale field shear tests on ten specimens of the red-sandstone embankment at a highway in Hunan, China, were performed to examine mechanical characteristics and parameters of red-sandstone. The curves of thrust-displacement, failure mode, and shear strength parameters for red-sandstone with different water contents, different compactions, and different grain size distributions were obtained from the tests. A practical procedure of in-situ test for red-sandstone embankment was proposed to normalize the test equipment and test steps. Based on three-dimensional thrust-sliding limit equilibrium method, the formulas for calculating strength parameters of red-sandstone considering three-dimensional sliding surface were inferred. The results show that red-sandstone has typical complete curves of stress-strain, strain softening, which are caused by the special structure of red-sandstone; water content and compaction are important factors for strength and failure mode of red-sandstone; The average value of cohesion and internal friction angle of the specimens calculated by three-dimensional technique are 21.56 kPa and 29.29°, respectively, and those by traditional two-dimensional method are 25.52 kPa and 33.76°, respectively.

The effect of electrochemical chloride extraction (ECE) on bond strength between steel bar and freeze-thaw concrete contaminated by chloride was experimentally investigated for beam specimens with dimensions of 100 mm×100 mm×400 mm. During the experiment, 3% NaCl (vs mass of cement, mass fraction) was mixed into concrete to simulate chloride contamination, and the specimens experienced 0, 25, 50, 75 freeze-thaw cycles before ECE. In the process of ECE, different current densities and durations were adopted. It is indicated that the bond strength between reinforcement and concrete decreases with the increase of freeze-thaw cycles; the more the current and the electric quantity of ECE are, the more the loss of bond strength is; and the largest loss is up to 58.7%. So, it is important to choose proper parameters of ECE for the reinforced concrete structures contaminated by chloride and subjected to freeze-thaw cycles.

For the purpose of describing the deformation characteristics of rocks, the effect of volume changes on mechanical properties of rocks should be taken into account with relation to the development of constitutive model. Firstly, rocks are divided into three parts, i.e., voids, a damaged part and an undamaged part in the course of loading. The void ratio was applied to describing the changes of voids or pores during the deformation process. Then, using statistical damage theory, a constitutive model was developed for rocks to describe their strain softening and hardening on the basis of investigating the relationship between the net stress and apparent stress, in which the influence of volume changes on rock behavior was correctly taken into account, such as the initial phase of compaction and the latter stage of dilation. Thirdly, a method of determining model parameters was also presented. Finally, this model was used to compare the theoretical results with those observed from experiments under conventional triaxial loading conditions.

A new “conceptual” design named “double pull” specimen was proposed in order to measure the bond-slip (σ−τ) relationship of fiber reinforced polymer (FRP)-to-concrete interface more accurately. A finite element analysis (FEA) was performed for preliminarily evaluating the suitability of the proposed conceptual double pull specimen. Through the FEA, it was indicated that the FRP-to-concrete interface of the proposed conceptual specimen might subject to a much higher load level than that of the most commonly used simple shear specimen, showing a great potential for measuring σ−τ relationship more accurately. In the light of the conceptual specimen, a kind of “practical” double pull specimen was developed and proved to be more suitable for measuring σ−τ relationship through an exploratory experimental study with 20 specimens. Consequently, an experimental program with 10 double pull specimens was performed for measuring the ultimate slip σ_u which was difficult to capture by using the existing specimens. It is shown that the range of σ_u is 0.31–0.52 mm based on the test results. The suggestion for improving the measure method is also put forward.

According to the chaotic and non-linear characters of power load data, the time series matrix is established with the theory of phase-space reconstruction, and then Lyapunov exponents with chaotic time series are computed to determine the time delay and the embedding dimension. Due to different features of the data, data mining algorithm is conducted to classify the data into different groups. Redundant information is eliminated by the advantage of data mining technology, and the historical loads that have highly similar features with the forecasting day are searched by the system. As a result, the training data can be decreased and the computing speed can also be improved when constructing support vector machine (SVM) model. Then, SVM algorithm is used to predict power load with parameters that get in pretreatment. In order to prove the effectiveness of the new model, the calculation with data mining SVM algorithm is compared with that of single SVM and back propagation network. It can be seen that the new DSVM algorithm effectively improves the forecast accuracy by 0.75%, 1.10% and 1.73% compared with SVM for two random dimensions of 11-dimension, 14-dimension and BP network, respectively. This indicates that the DSVM gains perfect improvement effect in the short-term power load forecasting.

The effects of surface energy on phase change of water vapor at initial stage of frost growth were studied to find an effective method of restraining frost growth. The mechanism of restraining frost growth by low energy surface (bigger contact angle) was analyzed based on crystal growth theory. Then, the phase change of water vapor and the process of frost growth on the copper and wax energy surfaces were observed using microscope. The results indicate that it is difficult for wax surface (low energy surface), on which there are still water droplets at 100 s, to form critical embryo, so frost growth can be restrained in a way. Water formation, droplet growth, ice formation and dendritic ice growth processes happen on both surfaces, ordinally. But the ice beads, with larger average diameter and sparse distribution on the wax surface, form later (at about 300 s) than that on the copper surface, and the dendritic ice also appears later. All of these support that ice crystal formation and dendritic crystal growth at initial stage of frost growth can be retarded on the low energy surface.

In order to evaluate and integrate travel time reliability and capacity reliability of a road network subjected to ice and snowfall conditions, the conceptions of travel time reliability and capacity reliability were defined under special conditions. The link travel time model (ice and snowfall based-bureau public road, ISB-BPR) and the path choice decision model (elastic demand user equilibrium, EDUE) were proposed. The integrated reliability was defined and the model was set up. Monte Carlo simulation was used to calculate the model and a numerical example was provided to demonstrate the application of the model and efficiency of the solution algorithm. The results show that the intensity of ice and snowfall, the traffic demand and supply, and the requirements for level of service (LOS) have great influence on the reliability of a road network. For example, the reliability drops from 65% to 5% when the traffic demand increases by 30%. The comprehensive performance index may be used for network planning, design and maintenance.