The manifold physical signals including micro resistance, infrared thermal signal and acoustic emission signal in the tensile test for double-material friction welding normative samples were monitored and collected dynamically by TH2512 micro resistance measuring apparatus, flir infrared thermal camera and acoustic emission equipment which possesses 18 bit PCI-2 data acquisition board. Applied acoustic emission and thermal infrared NDT (non-destructive testing) means were used to verify the feasibility of using resistance method and to monitor dynamic damage of the samples. The research of the dynamic monitoring system was carried out with multi-information fusion including resistance, infrared and acoustic emission. The results show that the resistance signal, infrared signal and acoustic emission signal collected synchronously in the injury process of samples have a good mapping. Electrical, thermal and acoustic signals can more accurately capture initiation and development of micro-defects in the sample. Using dynamic micro-resistance method to monitor damage is possible. The method of multi-information fusion monitoring damage possesses higher reliability, which makes the establishing of health condition diagnosing and early warning platform with multiple physical information monitoring possible.

Carrying on a series of compression and shear tests by a large number of specimens, reliabilities of T300/QY8911 laminated composite were studied when dispersibility models were described. The results show that the stress is linearly dependent on the strain and the damage modes of specimens are brittle fracture for both kinds of tests. Dispersibility models of compression and shear strength are expressed as R_c∼N(415.39, 6 586.36) and R_s∼ln(5.071 8, 0.155 3), respectively. When normal and lognormal distributions were used to describe the dispersibility models of compression and shear strength, and the compression or shear load follows the normal distribution, the almost same failure probability can be obtained from different reliability analysis methods.

In order to investigate the tensile bond anchorage properties of Australian 500N steel bars in concrete, 111 pullout tests were conducted. The precise bond slip values have been gained by using the laser displacement sensor with high resolution, including the complete bond-slip curves. How the main anchorage factors such as concrete strength, bar diameter (8, 10, 12, 16, 20, 24, 28, 32 and 36 mm) the concrete covered, embedded length and transverse reinforcement influencing the bond anchorage properties was studied under tensile condition. The process of the tensile force-slip failure for Australian 500N reinforcing steel can be divided into five stages: elastic stage, local slip stage, slip in ascent stage, slip in descent stage and remnant stage. The formula for calculating the tensile bond strength of Australian 500N reinforcing bar in concrete was proposed according to the test results, including the consistent model for tensile bond-slip relationship.

The stress corrosion crack (SCC) susceptibility of ultra-high strength steel AerMet 100 was investigated by slow strain rate technique (SSRT), tensile with polarization and surface analysis technique. The curves of t_f^Cl/t_f^W-strain rate are divided into three regions: stress-dominated region, SCC-dominated region, and corrosion-dominated region, so as the curves of ɛ_f^Cl/ɛ_f^W-strain rate and t_m/t_f-strain rate. The results of tensile tests with polarization show that the main SCC mechanism of AerMet 100 is anodic dissolution, which controls the corrosion process. The three regions have been discussed according to the relationship between the rate of slip-step formation and the rate of dissolution. Fracture appearances in different environments were analyzed by scanning electron microscopy (SEM). SCC fracture appears as a mixture of intergranular and dimples, while it is totally dimples in the inert environment. The ɛ_f becomes the parameter to predict t_f because the relationship between ɛ_f^Cl/ɛ_f^W and t_f^Cl/t_f^W is a straight line for AerMet 100.

The effects of alkali oxides (Na₂O and K₂O) addition on both the sintering behavior and dielectric properties of Ca-Al-B-Si-O glass/Al₂O₃ composites were investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results show that the increasing amount of alkali oxides in the glass causes the decrease of [SiO₄], which results in the decrease of the continuity of glass network, and leads to the decrease of the softening temperature T_f of the samples and the increasing trend of crystallization. And that deduces corresponding rise of densification, dielectric constant, dielectric loss of the low temperature co-fired ceramic (LTCC) materials and the decrease of its thermal conductivity. By contrast, the borosilicate glass/Al₂O₃ composites with 1.5% (mass fraction) alkali oxides sintered at 875 °C for 30 min exhibit better properties of a bulk density of 2.79 g/cm³, a porosity of 0.48%, a λ value of 2.28 W/(m·K), a ɛ_r value of 7.82 and a tan δ value of 9.1×10⁻⁴ (measured at 10 MHz).

The crystalline structure and surface morphology of TiO₂ semiconductor coating play an important role in the conversion efficiency of dye-sensitized solar cells. In order to obtain TiO₂ coating with controllable morphology and high porosity, nanoporous TiO₂ films were fabricated on conducting glass (FTO) substrates, Ti thin films (1.5–2 μm) were deposited on conducting glass (FTO) substrates via the DC sputtering method, and then electrochemically anodized in NH₄F/ethylene glycol solution. The crystalline structure and surface morphology of the samples were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The influences of anodizing potential, electrolyte composition, and pH value on the surface morphology of nanoporous TiO₂ films were extensively studied. The growth mechanism of nanoporous TiO₂ films was discussed by current density variations with anodizing time. The results demonstrate that nanoporous TiO₂ films with high porosity and three-dimensional (3D) networks are observed at 30 V, when the NH₄F concentration in ethylene glycol solution is 0.3% (mass fraction) and the electrolyte pH value is 5.0.

Activated carbon fiber/carbon nanotube (ACF/CNT) composites were fabricated by chemical vapor deposition (CVD) process. The effects of pyrolysis temperature on properties of ACF/CNT composites, including BET specific surface area, mass increment rate and adsorption efficiency for rhodamine B in solution, were investigated by scanning electron microscopy. The results show that the pyrolysis temperature is a key factor affecting the qualities of ACF/CNT composites. The mass increment rate and BET specific surface area sharply decrease with the increase of pyrolysis temperatures from 550 °C to 850 °C and the minimum diameter of CNTs appears at 750 °C. The maximum adsorption efficiency of ACF/CNT composites for rhodamine B is obtained at 650 °C. ACF/CNT composites are expected to be useful in adsorption field.

The lg c-pH diagram of the CaCl₂-Ca(OH)₂-H₂O system and its two subsystems at 298.15 K are constructed according to the theory of thermodynamic equilibrium. The interaction characteristics between the solubility of CaCl₂ and Ca(OH)₂ can be found out from the diagrams. CaCl₂·6H₂O (s), Ca(OH)₂(s) and solution coexist when the pH value of solution is about 10.8. CaCl₂ with the minimum solubility of 1 682.4 g/L is in equilibrium with solution when the pH value is lower than 9.4, and Ca(OH)₂ with the minimum solubility of 2.749 g/L is in equilibrium with solution at the pH value over 12.1, which provides a theoretical basis for the treatment and reuse of calcium chloride mother liquor for collocating lime cream which is the precipitant in the process of synthesizing magnesium hydroxide.

Molecular iodine was first utilized for direct oxidation of α-isophorone (α-IP) to ketoisophorone (KIP) with molecule oxygen at room temperature and the effects of amount of iodine, solvents and reaction time were investigated extensively. The optimized result shows that 70.2% conversion of α-isophorone and 82.6% selectivity of ketoisophorone are obtained with 15% iodine (molar fraction) in acetonitrile under photoirradiation for 5 h. Moreover, the possible mechanism is proposed.

In order to reasonably utilize the abundant resources of high-phosphorus iron ore and ilmenite in China, the technology of top-blown smelting reduction with oxygen enrichment was used to smelt the mixed ore of high-phosphorus iron and ilmenite. The effect, which is related to basicity, reduction temperature, carbon-oxygen ratio and time of ventilated oxygen to iron recovery, dephosphorization rate, content of iron, phosphorus, sulfur and titanium in pig iron, was investigated in the experiment. The results show that an ideal outcome can be gained in condition of 6:4 ration on Mengqiao concentrate and Huimin iron ore, temperature of 1 500 °C, basicity of 1.3, 1.0 on molar ration of carbon to oxygen, time of 10 min on blowing-oxygen. The outcome is that there is no foamy slag in generation, a good separation of slag and iron, iron recovery with 91.41%, content of phosphorus with 0.27% and tilanium content less than 0.001%. The atmosphere of strong oxidizing in the upper of reduction container and high potential of oxygen in the composition of slag in this technique bring phosphorus, titanium and silicon into slag, which ensures less content of impurity in pig iron.

Brine, which is used to produce high-purity magnesia, was purified by XSC-700 to remove boron. Boron adsorption capacity of XSC-700 was investigated by varying the initial boron concentration, temperature, resin/brine ratio and stirring speed, while keeping the diameter at constant. The results show that boron adsorption capacity increases with increasing boron concentration, temperature, and decreases with increasing resin/brine ratio. And the stirring speed could slightly affect the boron adsorption capacity. The adsorption kinetics obeys the pseudo-second-order model. Equilibrium data were both examined by Freundlich and Langmuir isotherm equations and it can be well represented by the Freundlich isotherm equation.

A new intelligent anti-swing control scheme, which combined fuzzy neural network (FNN) and sliding mode control (SMC) with particle swarm optimization (PSO), was presented for bridge crane. The outputs of three fuzzy neural networks were used to approach the uncertainties of the positioning subsystem, lifting-rope subsystem and anti-swing subsystem. Then, the parameters of the controller were optimized with PSO to enable the system to have good dynamic performances. During the process of high-speed load hoisting and dropping, this method can not only realize the accurate position of the trolley and eliminate the sway of the load in spite of existing uncertainties, and the maximum swing angle is only ±0.1 rad, but also completely eliminate the chattering of conventional sliding mode control and improve the robustness of system. The simulation results show the correctness and validity of this method.

A new single degree-of-freedom (1 DOF) resonance device was developed. It mainly comprises a linear motor, a vibrating screen, a supporting spring set, a supporting frame and a damper set. Forces acting on the vibrating screen were found. A differential equation for describing the forces was set up. Equations that were used to evaluate the exciting force and exciting frequency in resonance were derived from the solution to the differential equation. In addition, an equation for evaluating the deformed magnitude of the damping springs in the damper set was presented so that the suitable damping may be obtained. Finally, a Matlab/Simulink model of the new 1 DOF resonance device was also built. Displacement-time curves of the vibrating screen under four conditions were obtained in the use of the Matlab/Simulink simulation. The curves indicate that it can shorten the time for the vibrating screen to be into the stable resonance with increasing the damping, and it can lengthen the time with increasing the vibrated mass or amplitude, but every given angular frequency cannot acquire the desired amplitude value of resonance.

For the purpose of engineering development for a new 8-step speed automatic transmission, a simplified dynamic model for this gearbox was established and key parameters which affected the shift quality were analyzed. Aiming at four different shift types, the ideal characteristics of shift clutch and engine control were set up. By using torque estimation method, PI slip control algorithm and engine coordinated control principle, the control model and transmission controller were well developed for three shift phases which included rapid-fill phase, torque phase and inertia phase. The testing environment on the rig and prototype vehicle level was built and the testing results obtained in ultimate condition could verify the accuracy and feasibility of this shift control strategy. The peak jerk during shift process was controlled within ±2 g/s where the smooth gearshift was obtained. The development proposal and algorithm have a high value for engineering application.

High quality mesh plays an important role for finite element methods in science computation and numerical simulation. Whether the mesh quality is good or not, to some extent, it determines the calculation results of the accuracy and efficiency. Different from classic Lloyd iteration algorithm which is convergent slowly, a novel accelerated scheme was presented, which consists of two core parts: mesh points replacement and local edges Delaunay swapping. By using it, almost all the equilateral triangular meshes can be generated based on centroidal Voronoi tessellation (CVT). Numerical tests show that it is significantly effective with time consuming decreasing by 40%. Compared with other two types of regular mesh generation methods, CVT mesh demonstrates that higher geometric average quality increases over 0.99.

Chaos synchronization of systems with perturbations was investigated. A generic nonlinear control scheme to realize chaos synchronization of systems was proposed. This control scheme is flexible and practicable, and gives more freedom in designing controllers in order to achieve some desired performance. With the aid of Lyapunov stability theorem and partial stability theory, two cases were presented: 1) Chaos synchronization of the system without perturbation or with vanishing perturbations; 2) The boundness of the error state for the system with nonvanishing perturbations satisfying some conditions. Finally, several simulations for Lorenz system were provided to verify the effectiveness and feasibility of our method. Compared numerically with the existing results of linear feedback control scheme, the results are sharper than the existing ones.

The algorithm of dense spectrum correction has been raised and proved based on the correction of discrete spectrum by fast Fourier transform. The result of simulation shows that such algorithm has advantages of high accuracy and small amount of calculation. The algorithm has been successfully applied to the analysis of vibration signals from internal combustion engine. To calculate discrete spectrum, fast Fourier transform has been used to calculate the discrete spectrum by the signals acquired by the sensors on the oil pan, and the signal has been extracted from the mixed signals.

Based on the analysis of the feature of cognitive radio networks, a relevant interference model was built. Cognitive users should consider especially the problem of interference with licensed users and satisfy the signal-to-interference noise ratio (SINR) requirement at the same time. According to different power thresholds, an approach was given to solve the problem of coexistence between licensed user and cognitive user in cognitive system. Then, an uplink distributed power control algorithm based on traditional iterative model was proposed. Convergence analysis of the algorithm in case of feasible systems was provided. Simulations show that this method can provide substantial power savings as compared with the power balancing algorithm while reducing the achieved SINR only slightly, since 6% SINR loss can bring 23% power gain. Through further simulations, it can be concluded that the proposed solution has better effect as the noise power or system load increases.

Too high energy consumption is widely recognized to be a critical problem in large-scale parallel computing systems. The LogP-based energy-saving model and the frequency scaling method were proposed to reduce energy consumption analytically and systematically for other two representative barrier algorithms: tournament barrier and central counter barrier. Furthermore, energy optimization methods of these two barrier algorithms were implemented on parallel computing platform. The experimental results validate the effectiveness of the energy optimization methods. 67.12% and 70.95% energy savings are obtained respectively for tournament barrier and central counter barrier on platforms with 2048 processes with 1.55%-8.80% performance loss. Furthermore, LogP-based energy-saving analytical model for these two barrier algorithms is highly accurate as the predicted energy savings are within 9.67% of the results obtained by simulation.

Wireless mesh network (WMN) is a new multi-hop network for broadband accessing to internet. However, there exists a server unfairness problem based on different hop distances in WMN. To solve this problem, the unfairness issue was analyzed in test-bed experiment and NS2 simulation. A dynamic queue management scheme E-QMMN was proposed, which allocates the queue buffer according to the hop distance of every flow. The experimental results show that the proposed scheme can not only increase the hop distance fairness of the legacy scheme at most 50%, but also reduce the average round trip time at least 29% in congested WMN environments.

A blind digital image forensic method for detecting copy-paste forgery between JPEG images was proposed. Two copy-paste tampering scenarios were introduced at first: the tampered image was saved in an uncompressed format or in a JPEG compressed format. Then the proposed detection method was analyzed and simulated for all the cases of the two tampering scenarios. The tampered region is detected by computing the averaged sum of absolute difference (ASAD) images between the examined image and a resaved JPEG compressed image at different quality factors. The experimental results show the advantages of the proposed method: capability of detecting small and/or multiple tampered regions, simple computation, and hence fast speed in processing.

The difficulty of multiple targets tracking is how to quickly fulfill the target matching from one frame image to another and fix the position of the target. In order to accurately choose target feature information for reliable matching, simplify operations under the reliable precondition, and realize precise moving objects tracking, an approach based on Kalman prediction and feature matching was proposed. The position of the target in next frame image was predicted by Kalman, and then the moving objects of two adjacent frames were matched by the centroid and area methods. When occlusion occurs, the best matching result was found to realize tracking by matching matrix algorithm. The simulation results show that the proposed method can achieve multiple targets tracking accurately and in real-time under complicated motion movements.

A trajectory generator based on vehicle kinematics model was presented and an integrated navigation simulation system was designed. Considering that the tight relation between vehicle motion and topography, a new trajectory generator for vehicle was proposed for more actual simulation. Firstly, a vehicle kinematics model was built based on conversion of attitude vector in different coordinate systems. Then, the principle of common trajectory generators was analyzed. Besides, combining the vehicle kinematics model with the principle of dead reckoning, a new vehicle trajectory generator was presented, which can provide process parameters of carrier anytime and achieve simulation of typical actions of running vehicle. Moreover, IMU (inertial measurement unit) elements were simulated, including accelerometer and gyroscope. After setting up the simulation conditions, the integrated navigation simulation system was verified by final performance test. The result proves the validity and flexibility of this design.

A novel multiple watermarks cooperative authentication algorithm was presented for image contents authentication. This algorithm is able to extract multiple features from the image wavelet domain, which is based on that the t watermarks are generated. Moreover, a new watermark embedding method, using the space geometric model, was proposed, in order to effectively tackle with the mutual influences problem among t watermarks. Specifically, the incidental tampering location, the classification of intentional content tampering and the incidental modification can be achieved via mutual cooperation of the t watermarks. Both the theoretical analysis and simulations results validate the feasibility and efficacy of the proposed algorithm.

To reduce the fuel consumption and emissions and also enhance the molten aluminum quality, a mathematical model with user-developed melting model and burning capacity model, were established according to the features of melting process of regenerative aluminum melting furnaces. Based on validating results by heat balance test for an aluminum melting furnace, CFD (computational fluid dynamics) technique, in association with statistical experimental design were used to optimize the melting process of the aluminum melting furnace. Four important factors influencing the melting time, such as horizontal angle between burners, height-to-radius ratio, natural gas mass flow and air preheated temperature, were identified by PLACKETT-BURMAN design. A steepest descent method was undertaken to determine the optimal regions of these factors. Response surface methodology with BOX-BEHNKEN design was adopted to further investigate the mutual interactions between these variables on RSD (relative standard deviation) of aluminum temperature, RSD of furnace temperature and melting time. Multiple-response optimization by desirability function approach was used to determine the optimum melting process parameters. The results indicate that the interaction between the height-to-radius ratio and horizontal angle between burners affects the response variables significantly. The predicted results show that the minimum RSD of aluminum temperature (12.13%), RSD of furnace temperature (18.50%) and melting time (3.9 h) could be obtained under the optimum conditions of horizontal angle between burners as 64°, height-to-radius ratio as 0.3, natural gas mass flow as 599 m³/h, and air preheated temperature as 639 °C. These predicted values were further verified by validation experiments. The excellent correlation between the predicted and experimental values confirms the validity and practicability of this statistical optimum strategy.

Matrix effects can significantly hamper the accuracy and precision of the analysis results of perfluorinated acids (PFAs) in environmental solid samples. Several methods, such as standard addition, isotopically labeled internal standards, clean-up of SPE (solid phase extraction) eluents by dispersive graphitized carbon sorbent and substitution of eletrospray ionization (ESI) source by atmosphere pressure photoionization (APPI) source, were demonstrated for elimination of matrix effects in quantitative analysis of PFAs in solid samples. The results indicate that matrix effects can be effectively eliminated by standard addition, but instrumental analysis time will be multiplied. Isotopically labeled internal standards can effectively negate matrix effects of PFAs with the same perfluorocarbon chain length, but is not valid for the other analytes. Although APPI can eliminate matrix effects for all analytes, it is only suitable for analysis of high pollution levels samples. Clean-up of SPE eluents by dispersive graphitized carbon sorbent not only effectively negate the impact of matrix effect, but also avoid frequent clean of the ESI in order to maintain instrumental sensitivity. Therefore, the best method for elimination of matrix effects is the usage of dispersive graphitized carbon sorbent for clean-up of SPE elution.

Cation ion-exchange resin particles (CERP)/polyethersulfone (PES) hybrid catalytic membranes were prepared by immerse phase inversion for the esterification of different free fatty acids (FFAs) (such as, dodecanoic acid, tetradecanoic acid, hexadecanoic acid and octadecadienoic acid) with methanol. The membranes were characterized by SEM, ion-exchange capacity and swelling degree test. It is found that dodecanoic acid has the highest FFAs conversion among the four acids for its stronger acidic and reactivity. Different effects of membrane annealing temperature, reaction temperature, molar ratio of methanol to FFAs and catalytic membrane loading on the esterification were investigated by the esterification of dodecanoic acid with methanol. The dodecanoic acid conversion reaches 97.5% under the optimal condition when the esterification reaction lasted for 8 h.

Assisted by framework of multimedia total exposure model for hazard waste sites (CalTOX), potential influences of scenario-uncertainty on multimedia health risk assessment (MHRA) and decision-making were quantitatively analyzed in a primary extent under the Chinese scenario case by deliberately varying the two key scenario-elements, namely conceptual exposure pathways combination and aim receptor cohorts choice. Results show that the independent change of one exposure pathway or receptor cohort could lead variation of MHRA results in the range of 3.6×10⁻⁶-1.4×10⁻⁵ or 6.7×10⁻⁶–2.3×10⁻⁵. And randomly simultaneous change of those two elements could lead variation of MHRA results at the range of 7.7×10⁻⁸-2.3×10⁻⁵. On the basis of the corresponding sensitivity analysis, pathways which made a valid contribution to the final modeling risk value occupied only 16.7% of all considered pathways. Afterwards, comparative analysis between influence of parameter-uncertainty and influence of scenario-uncertainty was made. In consideration of interrelationship among all types of uncertainties and financial reasonability during MHRA procedures, the integrated method how to optimize the entire procedures of MHRA was presented innovatively based on sensitivity analysis, scenario-discussion and nest Monte Carlo simulation or fuzzy mathematics.

A feasible method to improve the reliability and processing efficiency of large vibrating screen via the application of an elastic screen surface with multiple attached substructures (ESSMAS) was proposed. In the ESSMAS, every screen rod, with ends embedded into elastomer, is coupled to the main screen structure in a relatively flexible manner. The theoretical analysis was conducted, which consists of establishing dynamic model promoted from the fuzzy structure theory as well as calculating for the equivalent stiffness of each attached structure. According to the numerical simulation using the NEWMARK-β integration method, this assembling pattern significantly leads to the screen surface/rod having larger vibration intensity than that of the corresponding position on screen structure, which specifically, with an averaged acceleration amplitude increasing ratio of 11.37% in theoretical analysis and 20.27% in experimental test. The experimental results, within a tolerant error, also confirm the established model and demonstrate the feasibility of ESSMAS.

In order to quantify the characteristics of the surface of jointed rock mass, new equipment, the three-dimensional laser surface topography instrument, was used to accurately measure surface morphology of joints. Scan pictures and parameters were obtained to describe the rock joint surface characteristics, for example, the height frequency of surface, and mean square roughness. Using the method of fractal dimension, the values of joint roughness coefficient (JRC) were calculated based on the above parameters. It could access to the joint surface rock sample morphology of the main parameters of characteristic. The maximum peak height is 2.692 mm in the test joint plane. The maximum profile height is 4.408 mm. JRC value is 6.38 by fractal dimension computing. It belongs to the smooth joint surface. The results show that it is a kind of the effective method to quantitatively evaluate the surface topography by the three-dimensional laser surface topography instrument and the fractal dimension method. According to the results, during the process of underground large-scale mining, safe measures to prevent slip failure of the joint plane by controlling surface tension and shear mechanical response were proposed.

Based on the stress distribution characteristics of rock burst multiple sites, the criterion of horizontal stress inducing layer dislocation rock burst was established. Accordingly, the influencing factors were analyzed. The analysis results indicate that the stress condition, edge of elastic zone depth, supporting strength, and the friction angle and cohesion among coal stratum, roof and floor are sensitive factors. By introducing double-couple model, the layer dislocation rock burst was explained and the energy radiation characteristics were analyzed. The SOS micro-seismic monitoring system was applied to observe the rock burst hazards about a mining face. The results show that P- and S-wave energy radiations produced by rock burst have directional characteristics. The energy radiation characteristics of the 22 rock bursts occurring on 79Z6 long-wall face are basically the same as theoretical results, that is, the ratio of S-wave energy of sensor 4 to 6 is about 1.5 and that of P-wave is smaller than 0.5. The consistency of the monitored characteristics of the energy radiation theoretically increases with the total energy increasing.

Determination of distribution and magnitude of active earth pressure is crucial in retaining wall designs. A number of analytical theories on active earth pressure were presented. Yet, there are limited studies on comparison between the theories. In this work, comparison between the theories with finite element analysis is done using the PLAXIS software. The comparative results show that in terms of distribution and magnitude of active earth pressure, RANKINE’s theory possesses the highest match to the PLAXIS analysis. Parametric studies were also done to study the responses of active earth pressure distribution to varying parameters. Increasing soil friction angle and wall friction causes decrease in active earth pressure. In contrast, active earth pressure increases with increasing soil unit weight and height of wall. RANKINE’s theory has the highest compatibility to finite element analysis among all theories, and utilization of this theory leads to proficient retaining wall design.

The equations governing wind-induced internal pressure responses for a two-compartment building with a dominant opening and background porosity were derived. The unsteady form of the Bernoulli equation, the law of mass conservation, and adiabatic equation were used for the derivation. The precision of the governing equations was verified by a wind tunnel test on a rigid model of a low-rise building. The results show that the governing equations can effectively analyze the wind-induced internal pressure responses. The internal pressure responses in both compartments are suppressed due to the additional damping provided by background porosity. The responses of internal pressure in both compartments, especially in the compartment without an external opening, decrease with increased lumped leakage area.

As a new type of structure which has never been built, submerged floating tunnel was studied mainly by numerical simulations. To further study the seismic response of a submerged floating tunnel, the first model experiment of submerged floating tunnel (SFT) under the earthquake was carried out on the unique underwater shaking table in China. The experimental results show that vertical excitation induces larger response than horizontal and different inclination degrees of the tether also cause different seismic responses. Subsequently, based on the fluid-structure interaction theory, the corresponding numerical model is established. And comparing the numerical results with the experimental results, it is shown that the numerical results are basically identical with those of shaking table test. Numerical model adopted is effective for dynamic response of SFT.

A new technique for the analysis of the three-dimensional collapse failure mechanism and the ground surface settlements for the large-diameter shield tunnels were presented. The technique is based on a velocity field model using more different truncated solid conical blocks to clarify the multiblock failure mechanism. Furthermore, the shape of blocks between the failure surface and the tunnel face was considered as an entire circle, and the supporting pressure was assumed as non-uniform distribution on the tunnel face and increased with the tunnel embedded depth. The ground surface settlements and failure mechanism above large-diameter shield tunnels were also investigated under different supporting pressures by the finite difference method.

The high-flowing sand-concrete (HFSC) containing natural sands as aggregate was carried out. The high fluidity and stability of HFSC can be achieved by tailoring the mix design parameters, such as fine to coarse sand ratio, dosage of additions, water to binder ratio and dosage of admixtures. Mini-cone slump test, v-funnel time test and viscosity model parameters were used to characterize the behaviour of HFSC in fresh state. The mechanical compressive strength in 28 d was also determined. A factorial design approach was used to establish models highlighting the effect of each mix-parameter on measured properties of HFSC. The derived models are valid for mixtures made with 0 to 0.3 of dune sand to total sand ratio, 82 to 418 kg/m³ of marble powder, 0.42 to 0.46 of water/binder ratio and 1.3% to 1.9% of superplasticizer high water-reducer. The results show that the derived models constitute very efficient means for understanding the influence of key mix-parameters on HFSC properties and are useful in selecting the optimum mix proportions, by simulating their impact on fluidity, stability and compressive strength.

Based on the consideration of longitudinal warp caused by shear lag effects on concrete slabs and bottom plates of steel beams, shear deformation of steel beams and interface slip between steel beams and concrete slabs, the governing differential equations and boundary conditions of the steel-concrete composite box beams under lateral loading were derived using energy-variational method. The closed-form solutions for stress, deflection and slip of box beams under lateral loading were obtained, and the comparison of the analytical results and the experimental results for steel-concrete composite box beams under concentrated loading or uniform loading verifies the closed-form solution. The investigation of the parameters of load effects on composite box beams shows that: 1) Slip stiffness has considerable impact on mid-span deflection and end slip when it is comparatively small; the mid-span deflection and end slip decrease significantly with the increase of slip stiffness, but when the slip stiffness reaches a certain value, its impact on mid-span deflection and end slip decreases to be negligible. 2) The shear deformation has certain influence on mid-span deflection, and the larger the load is, the greater the influence is. 3) The impact of shear deformation on end slip can be neglected. 4) The strain of bottom plate of steel beam decreases with the increase of slip stiffness, while the shear lag effect becomes more significant.

NT build 443, or profile fitting method, is often used to measure the diffusion coefficient of chloride in concrete. However, this method is quite laborious and needs special equipment. Colorimetric method is a quick and simple method to measure the penetration depth of chloride by spraying 0.1 mol/L silver nitrate solution. The objective of this work is to study the possibility of the use of colorimetric method in the calculation of non-steady-state diffusion coefficient. Twelve concrete mixtures with different supplementary cementitious materials and water-to-cement ratios of 0.35, 0.48 and 0.6 were used for study. According to NT build 443, the concrete specimens were immersed in 165 g/L NaCl (2.8 mol/L) solution for 42 d. Both water-soluble (convert to free chloride) chloride and acid-soluble chloride at different layers of specimens were measured. The results show that the mean value of free chloride concentration at the color change boundary c_d was 0.306 mol/L. The surface free chloride concentration c_s was obtained by profile fitting method, which was 40% lower than the chloride concentration of exposure solution after an immersion period of 42 d. Chloride diffusion coefficients obtained by the colorimetric method was not well correlated with those obtained by profile fitting method.

The improvement of question soils with cement shows great technical, economic and environmental advantages. And interest in introducing electrical resistivity measurement to assess the quality of cement treated soils has increased markedly recently due to its economical, non-destructive, and relatively non-invasive advantages. This work aims to quantify the effect of cement content (a_w), porosity (n_t), and curing time(T) on the electrical resistivity (ρ) and unconfined compression strength (UCS) of cement treated soil. A series of electrical resistivity tests and UCS tests of cement treated soil specimen after various curing periods were carried out. A modified Archie empirical law was proposed taking into account the effect of cement content and curing period on the electrical resistivity of cement treated soil. The results show that n_t/(a_w·T) and n_t/(a_w·T^1/2) ratio are appropriate parameters to assess electrical resistivity and UCS of cement treated soil, respectively. Finally, the relationship between UCS and electrical resistivity was also established.

To explore the stabilization effect of stabilizing agent GX07 on treating organic soil and the influence of organic matter on the strength development of stabilized soil, artificial organic soil with various organic matter content was obtained by adding different amounts of fulvic acid into non-organic clay, and then liquid-plastic limit tests were carried out on the artificial organic soil. Meanwhile, unconfined compressive strength (UCS) tests were performed on cement-only soil and composite stabilized soil, respectively. The test results indicate that the plastic limit of soil samples increases linearly, and the liquid limit increases exponentially as the organic matter content increases. The strength of stabilized soil is well correlated with the organic matter content, cement content, stabilizing agent content and curing time. When the organic matter content is 6%, as the cement content varies in the range of 10%–20%, the strength of cement-only soil increases from 88.5 to 280.8 kPa. Once 12.6% GX07 is added into the mix, the strength of stabilized soil is 4.93 times compared with that of cement-only soil. GX07 can obviously improve the strength of cemented-soil and has a good economic applicability. A strength model is proposed to predict strength development.

Many construction and post-construction problems have been reported in the literature when saline soils have been used without understanding of their abnormal behavior, especially their inferior bearing capacity in the natural condition. The strength of these soils further decreases on soaking. Saline soil deposits cover extensive areas in central Iran and are associated with geotechnical problems such as excessive differential settlement, susceptibility to strength loss and collapse upon wetting. Because of these characteristics, some of the roads constructed on saline soils in Taleghan area have exhibited deterioration in the form of raveling, cracking and landslides. The main objective of this work is to improve the load-bearing capacity of pavements constructed on Taleghan saline soils using lime and micro silica. Soil samples from Hashtgerd-Taleghan road were collected and tested for improving their properties using lime and micro silica at different dosages ranging from 0 to 6%. The load-bearing capacity of stabilized soil mixtures was evaluated using California Bearing Ratio (CBR) and unconfined compressive strength tests. The test results indicate that the lime improves the performance of soil significantly. The addition of 2% lime with 3% micro silica has satisfied the strength-deformation requirements. Therefore, improved soil can be used as a good subbase in flexible pavements.

Local inhomogeneity in totally asymmetric simple exclusion processes (TASEPs) with different hopping rates was studied. Many biological and chemical phenomena can be described by these non-equilibrium processes. A simple approximate theory and extensive Monte Carlo computer simulations were used to calculate the steady-state phase diagrams and bulk densities. It is found that the phase diagram for local inhomogeneity in TASEP with different hopping rates p is qualitatively similar to homogeneous models. Interestingly, there is a saturation point pair (α*, β*) for the system, which is decided by parameters p and q. There are three stationary phases in the system, when parameter p is fixed (i.e., p=0.8), with the increase of the parameter q, the region of LD/LD and HD/HD phase increases and the HD/LD is the only phase which the region shrinks. The analytical results are in good agreement with simulations.