A numerical approach for process optimization and microstructure evolution of lager-sized forging of aluminium alloy 7050 was proposed, which combined a commercial FEM code Deform 3D with empirical models. To obtain the parameters of empirical constitutive equation and dynamic recrystallization models for aluminium alloy 7050, the isothermal compression tests of 7050 samples were performed on Gleeble-1500 thermo-simulation machine in the temperature range of 250–450 °C and strain rate of 0.01–10 s⁻¹, and the metallograph analysis of the samples were carried out on a Leica DMIRM image analyzer. The simulation results show that the dynamic recrystallization in the central area of the billet occurs more easily than that on the edge. Repetitious upsetting and stretching processes make the billet deform adequately. Among several forging processes e.g. upsetting, stretching, rounding and flatting, the stretching process is the most effective way to increase the effective strain and refine the microstructure of the billet. As the forging steps increase, the effective strain rises significantly and the average grain size reduces sharply. Recrystallized volume fractions in most parts of the final forging piece reach 100% and the average grain size reduces to 10 μm from initial value of 90 μm.

Three observation methods were used to investigate the existing form and the behavior of rare earth during the sintering process of high activity mischmetal (RE, with lanthanum and cerium) doped WC-8%Co-0.048%RE(mass fraction) alloy with low carbon-containing level by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS), considering the fact that the addition amount of rare earth in the alloy is very minute. The directional migration process and mechanism of cerium were discussed. First, the sinter skin (surface) is observed. It is shown that there exists a dispersedly distributed cerium containing oxide on the sinter skin, and lanthanum in these cerium enrichment positions is very minute. Secondly, the polished section is observed, and lanthanum containing phase/micro-zone in the alloy is identified. Finally, based on the fact that the fracture of cemented carbide is resulted from the heterogeneous phase or other defects within the microstructure, the fracture surface is observed and cerium containing phase/micro-zone in the fracture source approximately 260 μm from the surface is identified. These combined observations reveal adequately the fact that lanthanum and cerium get separated and cerium predominantly migrates towards the surface during the sintering process.

[SiO₂/FePt]₅/Ag thin films were deposited by RF magnetron sputtering on the glass substrates and post annealing at 550 °C for 30 min in vacuum. Vibrating sample magnetometer and X-ray diffraction analyser were applied to study the magnetic properties and microstructures of the films. The results show that without Ag underlayer [SiO₂/FePt]₅ films deposited onto the glass are FCC disordered; with the addition of Ag underlayer [SiO₂/FePt]₅/Ag films are changed into L1₀ and (111) mixed texture. The variation of the SiO₂ nonmagnetic layer thickness in [SiO₂/FePt]₅/Ag films indicates that SiO₂-doping plays an important role in improving the order parameter and the perpendicular magnetic anisotropy, and reducing the grain size and intergrain interactions. By controlling SiO₂ thickness the highly perpendicular magnetic anisotropy can be obtained in the [SiO₂ (0.6 nm)/FePt (3 nm)]5/Ag (50 nm) films and highly (001)-oriented films can be obtained in the [SiO₂ (2 nm)/FePt (3 nm)]₅/Ag (50 nm) films.

A general, simple and economic synthetic method for synthesizing carbon nanofibers was presented. In the method, ethanol was employed as carbon source; metal salts such as nickel nitrate, ferric nitrate and ferric chloride were used as catalyst precursor respectively; copper plate was employed as the support material. A lot of products were obtained by catalytic combustion deposition of ethanol vapor. Then the as-prepared carbon nanofibers were characterized by field-emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, energy dispersion X-ray spectroscopy and selected-area electron diffractometry. By analyzing the results of characterization, the conclusions are as follows: 1) the large catalyst particles tend to form large-diameter CNFs, small catalyst particles are inclinable to form small-diameter CNFs; 2) the morphology of the catalyst can affect the final morphology of the CNFs. Moreover, the possible growth mechanisms were proposed and the degree of graphitization of samples was estimated by Raman spectroscopy characterization.

The resistance arrangements of the flexes connecting with the cathode bus bar in aluminum reduction cells were generalized as three modes. In each mode the universal method to select proper resistivity of the flexes was induced respectively to insure that the current in local group of flexes was equal. Furthermore, a 350 kA aluminum reduction cell based electric field model was developed by finite element method to evaluate the effect of the method. Suggestions on selection of three modes were also put forward. The results show that the methods of resistance optimization can reduce the current variation about 180 A compared with that in original case.

The CaO doped 10NiO-NiFe₂O₄ composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe₂O₄ composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe₂O₄ when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m^1/2, which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe₂O₄ composite ceramics.

With citric acid as a polymeric agent layered LiNi_0.8Co_0.2O₂ materials were synthesized by a spray pyrolysis method. The LiNi_0.8Co_0.2O₂ particles were characterized by means of XRD, SEM and TEM. The electrochemical performances of LiNi_0.8Co_0.2O₂ particles were studied in a voltage window of 3.00–4.35 V and at a current density of 30 mA/g. The results show that in the pilot-scale spray pyrolysis process, the morphology of particles is dependent upon the precursor concentration and flux of carrier gas. The initial discharge capacity of the LiNi_0.8Co_0.2O₂ particles at 720 °C for 12 h °C is 187.3 mA·h/g, and the capacity remains 96.8 % with excellent cycleability after 30 cycles. The LiNi_0.8Co_0.2O₂ samples synthesized under the optimized conditions by the spray pyrolysis method shows a good electrochemical performance.

Alumina coated LiNi_1/3Mn_1/3Co_1/3O₂ particles were obtained by a simple method of solid state reaction at room temperature. The reaction mechanism of solid state reaction at room temperature was investigated. The structure and morphology of the coating materials were investigated by XRD, SEM and TEM. The electrochemical performances of uncoated and Al₂O₃-coated LiNi_1/3Co_1/3Mn_1/3O₂ cathode materials were studied within a voltage window of 3.00–4.35 V at current density of 30 mA/g. SEM, TEM and EDS analytical results indicate that the surface of LiNi_1/3Mn_1/3Co_1/3O₂ particles is coated with very fine Al₂O₃ composite, which leads to the improved cycle ability though a slight decrease in the first discharge capacity is observed. It is proposed that surface treatment by solid state reaction at room temperature is a simple and effective method to improve the cycle performance of LiNi_1/3Co_1/3Mn_1/3O₂ particles.

Based on the Fourier transform, a new shape descriptor was proposed to represent the flame image. By employing the shape descriptor as the input, the flame image recognition was studied by the methods of the artificial neural network(ANN) and the support vector machine(SVM) respectively. And the recognition experiments were carried out by using flame image data sampled from an alumina rotary kiln to evaluate their effectiveness. The results show that the two recognition methods can achieve good results, which verify the effectiveness of the shape descriptor. The highest recognition rate is 88.83% for SVM and 87.38% for ANN, which means that the performance of the SVM is better than that of the ANN.

1′-cysteaminecarbonyl-1-glutathionecarbonyl-ferrocene (Fc-GSH) was synthesized from ferrocene dicarboxylic acid and reduced glutathione (GSH) with 4 steps. IR and ¹H-NMR were used to characterize the products. Then Fc-GSH was immobilized on the surface of gold electrode. Cyclic votammetry (CV) was adopted to investigate the electrochemical properties of this Fc-GSH modified electrode in the absence and presence of Cd²⁺ aqueous solutions. The peak oxidation potential (E_a) and reduction potential (E_c) of Fc-GSH modified electrode were observed at E_a = 0.74 V and E_c = 0.64 V (vs Ag/AgCl) before the accumulation of Cd²⁺. This redox process is a monoelectron chemical reaction. The anodic shift is about 80 mV in the presence of 20 nmol/L of Cd²⁺ aqueous solution. Moreover, this shift is in proportion to the concentration of Cd²⁺ when the concentration of Cd²⁺ is lower than 20 nmol/L. So the modified electrode can be used as probes to detect cadmium ions with the limit of 0.1 nmol/L by cyclic voltammetry.

Electrokinetic and contact angle measurements were used to discuss the interfacial interaction on bio-leaching of pyrite mineral. Surface energy parameters of pyrite mineral and thiobacillus ferrooxidans were obtained by calculating according to formula of Young’s equation and contact angle measurements. The results show that surface energy of thiobacillus ferrooxidans is much higher than that of pyrite mineral, and the reaction of pyrite mineral with thiobacillus ferrooxidans causes the reduction of the pyrite surface energy. The interfacial interaction energies between pyrite mineral and thiobacillus ferrooxidans were also obtained based on polar interfacial interaction theory and electrokinetic and contact angle measurements. The thermodynamics approach only considering Lifshitz-van der Waals and Lewis acid-base interaction fails to explain the adhesion behavior of the bacteria, but the extended Derjaguin-Landan-Verwey-Overbeek theory concerning Lifshitz-van der Waals and Lewis acid-base and the electrostatic can exactly predict interfacial interaction.

A novel zinc-rich pigment based on P(St-BA-MAA-SPAA) nano-latex was obtained, which is suitable for the use in hot alkali liquid medium. The nano-latex was synthesized by active emulsifier latex polymerization method with monomers of styrene (St), butylacrylate (BA), methylacrylic acid(MAA) in the presence of active emulsifier 3-sulfopropylacrylate(SPAA). The synthesis condition and properties of the latex were investigated. And the anti-corrosive property of the resultant zinc-rich coating was studied. The results show that the nano-latex is self-stabilized and has a narrow particle diameter distribution, the average diameter of the latex particles is 71 nm. Zinc powders can be evenly dispersed in the nano-latex, which indicates that the P(St-BA-MAA-SPAA) nano latex can be used as the binder of zinc-rich coating. The resultant zinc-rich coating is able to resist the invasion of hot alkali solution(the temperature is 95 °C and the pH value is 14) for 480 h and the exposure time in salt spray is 1 200 h. Moreover, the coating shows good thermal conductivity and static electricity properties, its thermal conductivity and electric resistivity are 21–37 W/(m·K) and 6.7×10⁵–3.5×10⁶ Ω·cm, respectively.

Microwave assisted-semi bionic extraction (MASBE) process for lignans from Fructus Forsythiae was studied. The influences of solvent pH value, microwave power, dosage of solvent and irradiation time were investigated. Optimum extracting parameters were determined by orthogonal experiments as follows: pH value of solvent at first extraction is 5.5–6.0, that at the second extraction is 7–8; microwave power is 700 W; mass ratio of Fructus Forsythiae to water is 1:12; irradiation time is 10 min, and extracting times is two. Under these optimal conditions, the yield of lignans reaches 0.364%. Compared with the conventional extraction methods, the MASBE process has the advantages of high extraction rate, high extraction selectivity.

The flammability characterization and thermal composition of polymers flame retarded by decabromodiphenylethane (DBDPE) and antimony trioxide (Sb₂O₃) were studied by cone calorimeter and thermogravimetry (TG). The results show that ABS/DBDPE/Sb₂O₃ has the similar flammability parameters and thermal composition curves to ABS/DBDPO/Sb₂O₃. It suggests that DBDPE/Sb₂O₃ has the similar flame retardant behavior to DBDPO/Sb₂O₃. The heat release rate (HRR) and the effect heat combustion (EHC) curves of polymers flame retarded by DBDPE/Sb₂O₃ all decrease, but the mass loss rate (MLR) curve slightly increase. It shows that the decrease of HRR is not due to the increase of char formation ratio but the generation of incombustible gases. The major flame retardant mechanism of DBDPE/Sb₂O₃ is gas phase flame retardant mechanism. Increasing content of Sb₂O₃ in DBDPE/Sb₂O₃ can improve the flame retardant property and thermal stability of acrylonitrile butadiene styrene. Sb₂O₃ has a good synergistic effect with DBDPE.

Based on a typical multi-arch tunnel in a freeway, the fast Lagrangian analysis of continua in 3 dimensions(FLAC^3D) was used to calculate the surrounding rock deformation of the tunnel under which the effect of underground water seepage flow was taken into account or not. The distribution of displacement field around the multi-arch tunnel, which is influenced by the seepage field, was gained. The result indicates that the settlement values of the vault derived from coupling analysis are bigger when considering the seepage flow effect than that not considering. Through the contrast of arch subsidence quantities calculated by two kinds of computation situations, and the comparison between the calculated and measured value of tunnel vault settlement, it is found that the calculated value(5.7–6.0 mm) derived from considering the seepage effect is more close to the measured value(5.8–6.8 mm). Therefore, it is quite necessary to consider the seepage flow effect of the underground water in aquiferous stratum for multi-arch tunnel design.

The interaction between pile and soft soil of the passive pile group subjected to soil movement was analyzed with three-dimensional finite element model by using ANSYS software. The soil was assumed to be elastic-plastic complying with the Drucker-Prager yield criterion in the analysis. The large displacement of soil was considered and contact elements were used to evaluate the interaction between pile and soil. The influences of soil depth of layer and number of piles on the lateral pressure of the pile were investigated, and the lateral pressure distributions on the (2×1) pile group and on the (2×2) pile group were compared. The results show that the adjacent surcharge may result in significant lateral movement of the soft soil and considerable pressure on the pile. The pressure acting on the row near the surcharge is higher than that on the other row, due to the “barrier” and arching effects in pile groups. The passive load and its distribution should be taken into account in the design of the passive piles.

Through integrating the state of the art scientific knowledge in different research fields, some potential mechanisms of large-scale movements of underground pore-fluids such as H₂O and CO₂ in the continental lithosphere were presented and discussed. The results show that the generation and propagation of porosity waves are important mechanisms to transport mass and heat fluxes from the continental lithospheric mantle into the lower continental crust; the generation and propagation of porosity waves, pore-fluid flow focusing through lower and middle crustal faults, advection of pore-fluids through the lower and middle crust, and whole-crust convection in some particular cases are important mechanisms to transport mass and heat fluxes from the lower into the upper continental crust; heat and mass transport through convective pore-fluid flow is the most effective mechanism of ore body formation and mineralization in hydrothermal systems; due to heat and mass exchange at the interface between the earth surface, hydrosphere and atmosphere, it is very important to consider the hydro-geological effect of the deep earth pore-fluids such as H₂O and CO₂ on the global warming and climate change in future investigations.

Based on the basic geological features of Yixingzhai gold deposit, the geological features, classification and relation to mineralization of breccia pipes were discussed by surveying the xenoliths and breccia’s mineral composition, structure and construction, typical mineralization alteration phenomenon on field and microscopic anatomy in breccia pipes. And the ore-controlling mechanism and the formation mechanism of the blasting breccia pipes were investigated. The main conclusion shows that Hewan and Nanmenshan breccia pipes nearby the NW-striking deep fault are shaped earlier, belonging to the acidic siliceous ingredient production of ultra-hypabyssal magmatic in the late magma stage; Tietangdong and Nanmenshan breccia pipes that are shaped latter are the ultra-hypabyssal auriferous fluid production composed mainly of the skarn in the hydrothermal stage after the magma period. Both root in the unified deep magmatic chamber, belonging to differentiation derivatives at different stages in the deep magmatic chamber.

Fracture evolution process (initiation, propagation and coalescence) of cracked rock was observed and the force—displacement curves of cracked rock were measured under uniaxial cyclic loading. The tested specimens made of sandstone-like modeling material contained three pre-existing intermittent cracks with different geometrical distributions. The experimental results indicate that the fatigue deformation limit corresponding to the maximal cyclic load is equal to that of post-peak locus of static complete force-displacement curve; the fatigue deformation process can be divided into three stages: initial deformation, constant deformation rate and accelerative deformation; the time of fracture initiation, propagation and coalescence corresponds to the change of irreversible deformation.

Based on Bishop’s model and by applying the first and second order mean deviations method, an approximative solution method for the first and second order partial derivatives of functional function was deduced according to numerical analysis theory. After complicated multi-independent variables implicit functional function was simplified to be a single independent variable implicit function and rule of calculating derivative for composite function was combined with principle of the mean deviations method, an approximative solution format of implicit functional function was established through Taylor expansion series and iterative solution approach of reliability degree index was given synchronously. An engineering example was analyzed by the method. The result shows its absolute error is only 0.78% as compared with accurate solution.

Based on the fact that the shear stress along anchorage segment is neither linearly nor uniformly distributed, the load transfer mechanism of the tension type anchor was studied and the mechanical characteristic of anchorage segment was analyzed. Shear stress-strain relationship of soil surrounding anchorage body was simplified into three-folding-lines model consisting of elastic phase, elasto-plastic phase and residual phase considering its softening characteristic. Meanwhile, shear displacement method that has been extensively used in the analysis of pile foundation was introduced. Based on elasto-plastic theory, the distributions of displacement, shear stress and axial force along the anchorage segment of tension type anchor were obtained, and the formula for calculating the elastic limit load was also developed accordingly. Finally, an example was given to discuss the variation of stress and displacement in the anchorage segment with the loads exerted on the anchor, and a program was worked out to calculate the anchor maximum bearing capacity. The influence of some parameters on the anchor bearing capacity was discussed, and effective anchorage length was obtained simultaneously. The results show that the shear stress first increases and then decreases and finally trends to the residual strength with increase of distance from bottom of the anchorage body, the displacement increases all the time with the increase of distance from bottom of the anchorage body, and the increase of velocity gradually becomes greater.

The breakage mechanism of the polycrystalline diamond compact(PDC) cutters was analyzed by the energy theory of bending waves. The cutting tests of granite block were conducted on a multifunctional testing device by using the cutter at three kinds of negative fore angles of 30°, 45° and 60°. The results show that, when the edge of the PDC layer is broken, the layer of tungsten cobalt is broken a little under the angle of 30°, while the layer of tungsten cobalt is broken continuously under the angle of 60°, their maximum depths are about 2 and 7 mm respectively in the two cases. The eccentric distance mainly depends on the negative fore angle of the cutter. When the cutter thrusts into the rock under an attack angle of 60°, the energy of bending waves reaches the maximum since the eccentric distance is the maximum. So the damage of cutter is the most serious. This test result is consistent with the conclusion of theoretical analysis well. The eccentric distance from the axial line of cutter to the point of action between the rock and cutter has great effect on the breakage of the cutter. Thus during the process of cutting, the eccentric distance should be reduced to improve the service life of PDC cutters.

Based on the principle of Mahalanobis distance discriminant analysis (DDA) theory, a stability classification model for mine-lane surrounding rock was established, including six indexes of discriminant factors that reflect the engineering quality of surrounding rock: lane depth below surface, span of lane, ratio of directly top layer thickness to coal thickness, uniaxial comprehensive strength of surrounding rock, development degree coefficient of surrounding rock joint and range of broken surrounding rock zone. A DDA model was obtained through training 15 practical measuring samples. The re-substitution method was introduced to verify the stability of DDA model and the ratio of mis-discrimination is zero. The DDA model was used to discriminate 3 new samples and the results are identical with actual rock kind. Compared with the artificial neural network method and support vector mechanic method, the results show that this model has high prediction accuracy and can be used in practical engineering.

The motor and trailer cars of a high-speed train were modeled as a multi-rigid body system with two suspensions. According to structural characteristic of a slab track, a new spatial vibration model of track segment element of the slab track was put forward. The spatial vibration equation set of the high-speed train and slab track system was then established on the basis of the principle of total potential energy with stationary value in elastic system dynamics and the rule of “set-in-right-position” for formulating system matrices. The equation set was solved by the Wilson-ϑ direct integration method. The contents mentioned above constitute the analysis theory of spatial vibration of high-speed train and slab track system. The theory was then verified by the high-speed running experiment carried out on the slab track in the Qinghuangdao-Shenyang passenger transport line. The results show that the calculated results agree well with the measured results, such as the calculated lateral and vertical rail displacements are 0.82 mm and 0.9 mm and the measured ones 0.75 mm and 0.93 mm, respectively; the calculated lateral and vertical wheel-rail forces are 8.9 kN and 102.3 kN and the measured ones 8.6 kN and 80.2 kN, respectively. The interpolation method, that is, the lateral finite strip and slab segment element, for slab deformation proposed is of simplification and applicability compared with the traditional plate element method. All of these demonstrate the reliability of the theory proposed.

The effects of factors such as the molar ratio of H₂O to CH₄ (n(H₂O)/n(CH₄)), methane conversion temperature and time on methane conversion rate were investigated to build kinetic model for reforming of coke-oven gas with steam. The results of experiments show that the optimal conditions for methane conversion are that the molar ratio of H₂O to CH₄ varies from 1.1 to 1.3 and the conversion temperature varies from 1 223 to 1 273 K. The methane conversion rate is more than 95% when the molar ratio of H₂O to CH₄ is 1.2, the conversion temperature is above 1 223 K and the conversion time is longer than 0.75 s. Kinetic model of methane conversion was proposed. All results demonstrate that the calculated values by the kinetic model accord with the experimental data well, and the error is less than 1.5%.

In order to construct the data mining frame for the generic project risk research, the basic definitions of the generic project risk element were given, and then a new model of the generic project risk element was presented with the definitions. From the model, data mining method was used to acquire the risk transmission matrix from the historical databases analysis. The quantitative calculation problem among the generic project risk elements was solved. This method deals with well the risk element transmission problems with limited states. And in order to get the limited states, fuzzy theory was used to discrete the historical data in historical databases. In an example, the controlling risk degree is chosen as P(R_s⩾2) ⩽0.1, it means that the probability of risk state which is not less than 2 in project is not more than 0.1, the risk element R₃ is chosen to control the project, respectively. The result shows that three risk element transmission matrix can be acquired in 4 risk elements, and the frequency histogram and cumulative frequency histogram of each risk element are also given.

To improve the deficiency of the control system of finish cooling temperature (FCT), a new model developed from a combination of a multilayer perception neural network as the self-learning system and traditional mathematical model were brought forward to predict the plate FCT. The relationship between the self-learning factor of heat transfer coefficient and its influencing parameters such as plate thickness, start cooling temperature, was investigated. Simulative calculation indicates that the deficiency of FCT control system is overcome completely, the accuracy of FCT is obviously improved and the difference between the calculated and target FCT is controlled between −15 °C and 15 °C.

In order to study the problem that particle swarm optimization (PSO) algorithm can easily trap into local mechanism when analyzing the high dimensional complex optimization problems, the optimization calculation using the information in the iterative process of more particles was analyzed and the optimal system of particle swarm algorithm was improved. The extended particle swarm optimization algorithm (EPSO) was proposed. The coarse-grained and fine-grained criteria that can control the selection were given to ensure the convergence of the algorithm. The two criteria considered the parameter selection mechanism under the situation of random probability. By adopting MATLAB7.1, the extended particle swarm optimization algorithm was demonstrated in the resource leveling of power project scheduling. EPSO was compared with genetic algorithm (GA) and common PSO, the result indicates that the variance of the objective function of resource leveling is decreased by 7.9%, 18.2%, respectively, certifying the effectiveness and stronger global convergence ability of the EPSO.