The effect of surface damaged layer and Te enrichment layer of Hg_1-xMn_xTe on the indentation size were studied experimentally. Based on the results, the indentation size effect (ISE) of Hg_1−xMn_xTe were discussed using different models, including Meyer’s law, the power-law, Hays-Kendall approach and the theory of strain gradient plasticity. The results show that surface damaged layer weakens ISE of the wafers, but the Te enrichment layer reinforces it. The minimum test load necessary to initiate plastic deformation for different Hg_1−xMn_xTe wafers increases from 3.11 to 4.41 g with the increase of x from 0.05 to 0.11. The extrapolated surface hardness values of Hg_1−xMn_xTe are 347.21, 374.75, 378.28 and 391.51 MPa and the corresponding shear strength values are 694.53, 749.50, 756.56 and 783.12 MPa for Hg_1−xMn_xTe with the x values of 0.05, 0.07, 0.09 and 0.11, respectively.

A formula was brought forward to correlate residual strain with hardness measured by nanoindentation method. Using the formula, residual strains in prestrained aluminum alloy samples were evaluated. In order to compare with the calculated strain, such values were also measured by strain gauge method. The results show that the differences of the residual strain obtained by nanoindentation and strain gauge method are not more than 8%, which shows that the formula is suitable for characterizing residual strain of aluminum alloy.

The simulated fine grained heat-affected zone (FGHAZ) specimens for P92 welded joints were prepared by heat treatment, then the creep tests were carried out at 650 ℃ under the applied stress of 90−120 MPa to investigate high-temperature creep behavior of FGHAZ. The results show that the creep property of FGHAZ is much inferior to that of the base metal, which exhibits the much higher steady creep rate and shorter time to creep fracture. The power law equation can describe the steady creep rate dependence on applied stress, indicating that the stress exponent n of FGHAZ is distinguished between two regions with n=15.1 at high stresses (more than 100 MPa) and n=8.64 at lower stresses. Based on Monkman-Grant equation, the relationship between the secondary creep rate and time to rupture is obtained to evaluate the creep life of FGHAZ with the applied stress above 100 MPa.

The thermal expansion behavior of mercury indium telluride (MIT) crystals, Hg_(3−3x)In_2xTe₃(x=0.5), based on X-ray diffraction experimental data is studied at 298−573 K. The variation of the lattice parameter of MIT crystals with temperature was determined and the thermal expansion coefficient was deduced to be 6.18×10⁻⁶ K⁻¹. The results of the thermal expansion are fitted to polynomial expressions. It is found that the lattice parameter decreases quickly with temperature increasing at 298−330 K and then increases continuously up to 573 K. The minimum lattice parameter corresponds to a maximum shrinkage of 0.06%.

Lattice constants, total energies and densities of state of technetium(Tc) and rhenium(Re) with different crystalline structures were calculated with the GGA+PBE function, ultra-soft pseudo-potential and plane wave method in first-principles. The results were compared with those of projector augmented wave(PAW) method in first-principles and experimental data. The lattice stability results prove that HCP phase is the most stable phase, which agrees well with those of PAW method in first-principles and CALPHAD method. Further analyses of densities of state also give the same result of lattice stability for HCP-, FCC-, BCC-Tc and Re. Analyses of atomic populations show that the lattice stability of technetium and rhenium is probably related to the electrons in p and d state.

Crystal growth of tungsten during hydrogen reduction of tungsten oxide (WO₃) to prepare coarse grain tungsten powder at high temperature (950 ℃) was studied. The phase composition and morphologies of products were investigated by means of XRD and SEM. The results show that the reduction sequence of hydrogen reduction of WO₃ is WO₃→WO_2.9→W₁₈O₄₉→WO₂→W. The step of WO₂→W is the critical step which determines the grain size of tungsten powder. The partial pressure (p_H2O/p_H2) of H₂O within powder layer shows strong effect on the nucleation and grain growth of tungsten. By increasing the p_H2O/p_H2 within powder layer, well-developed coarse grain tungsten powder with particle size above 15 μm is obtained. After carburizing, the powder can be used to produce ultra-coarse grain cemented carbide with grain size above 5 μm.

The strips U deep drawing experiments were carried out to study the effect of die cavity dimension with an extension machine manufactured by SANS company. The effects of parameters were analyzed in deep drawing process under different experimental conditions, such as punch load, reduction of thickness, angle of U part and surface quality. The experiment results show that the punch load increases with the decrease of female radius, and larger blank holder force enlarges the range of increasing. With the increasing of blank holder force, the angle of U part increases, and the reduction of foil thickness at the corner becomes larger. Obvious scratch and accumulation at the die cavity corner were observed by SEM. The investigation results indicate that micro U deep drawing of foil is affected by micro die cavity dimension.

Heat shocks caused by alloy melt and coat spraying are the main reason of die plastic deformation and early fracture. Based on theoretical analysis of heat shock phenomenon, two characteristic parameters of die damage caused by heat shock were proposed, which are heat shock plastic deformation index (HSPI) and heat shock crack index (HSCI). The effect of heat shock on die plastic deformation and fracture behaviors was described quantitatively by these two parameters. HSPI represents approaching of heat shock stress to die yield stress. Plastic deformation will happen on a die if this index reaches 1. HSCI represents approaching of heat shock stress to die tensile strength. Die fracture will happen if this index reaches 1. According to theoretical analysis of heat transfer, theoretical models of HSPI and HSCI were established. It is found that, the smaller the interfacial thermal resistance (ITR) is, the higher the pouring temperature and die temperature are before heat shock, and the greater the HSPI and HSCI are, which can be fitted as exponential curves, linear and cubic curves.

The effect of thermomechanical treatment on the magnetic properties of Mn_85.5Fe_9.0Cu_0.5 alloy was studied by use of a materials testing machine, a vibrating sample magnetometer, an X-ray diffractometer, a homogeneously and adjustably magnetic field and strain gauges. The results show that the orientation of fct phase and magnetic domains is affected by the thermomechanical treatment. When the compressive strain of thermomechanical treatment is −1.2%, the magnetic-field-induced strain reaches the highest value in the adapted situation.

Based on the method of controlling welding stress with trailing, the electromagnetic force in coil-sheet system was simulated with finite element software ANSYS. The effect of parameters of coil on the electromagnetic force density f_y was analyzed. The results show that the maximum electromagnetic force density f_{y, max} in sheet appears in the position near the inner radius of single-turn coil. The position is independent of section shape of coil. f_{y, max} for flat coil is larger than that for long coil and the coil with wedge shape section, while section areas of all coils are equal to each other. The effect of turn number of multiple-turn coil on f_y is dependent on the loop resistance in circuit. The kind of coil with more turns and larger inductance is commended while there is larger loop resistance in circuit. f_y increases in a certain magnitude while a magnetic core is located in coil. However, the magnitude of f_y is limited by saturating magnetic flux of the core.

To obtain the damage effect in the process of elasto-plasticity deformation of quasi-brittle materials, the isotropic damage loading-unloading function and damage variable were introduced to non-continuous bifurcation. The critical bifurcation orientation and its corresponding hardening modulus for quasi-brittle materials were derived considering the effect of stiffness degradation and volumetric dilatancy under the assumption of isotropic damage. The relationships of localized orientation angle and maximal hardening modulus dependent on degree of damage and initial Poisson’s ratio of rock were explored. Comparative analyses were conducted to study the bifurcation of uniaxial tension-compression samples under the conditions of plane stress and plane strain. It is shown that as the initial Poisson’s ratio or degree of damage increases, the localization orientation angle of the plane uniaxial compression sample tends to be initiated to decrease. However, the localization orientation angle of the plane uniaxial tension sample tends to be initiated to increase. The sum of orientation angle under tension and compression conditions is 90˚. There are plane stress and plane strain cases of the maximum hardening modulus that is independent of the uniaxial compression and tension.

Explicit finite difference code was used to calculate the stability factors of shallow tunnels without internal support in limit state. The proposed method was formulated within the nonassociative plasticity. For the shallow tunnels in soft clay, without considering the influences of pore water pressure and dilatancy, numerical results were compared with the previously published solutions. From the comparisons, it is found that the present solutions agree well with the previous solutions. The accuracy of the strength reduction technique was demonstrated through the comparisons. The influence of the pore water pressure was discussed. For the shallow tunnels in dilatant cohesive-frictional soils, the dilatant analysis was carried out.

In view of the non-local phenomena appearing in the rock and concrete-like materials, the non-local damage and fracture model of rock and concrete-like materials was established through non-local method of Gaussian weighting function. The result indicates that, the stress of one point in the material is correlated not only to its strain history, but also to the interaction of the points in its certain adjacent region of the material. Based on the established non-local model, the numerical simulation of notch containing three-point bending beam was carried out. The results show that the grid sensitivities have been avoided and the fracture direction of the material has not been influenced by the grid shape, and the model proposed can be used to better simulate the damage developing process of the rock and concrete-like materials.

Using industrial titanyl sulfate solution as feedstock, titania white pigment was prepared by self-generated seeded thermal hydrolysis method. The influence of some factors (such as F value, volume ratio of pre-adding water to TiOSO₄, heating rate and pH of pre-adding water) on the structure and pigment properties of the as-prepared slurry metatitanic acid and titania samples were studied. The samples were characterized by XRD, particle size distribution, SEM and pigment properties test. The results show that all samples show anatase phase, and the calcined samples prepared under suitable conditions are with narrow particle size distribution and good pigment properties. All these influencing factors have great impacts on the hydrolysis velocity, nucleation rate, crystal growth rate, particle size distribution, crystal structure and pigment properties. The suitable F value is 1.73−1.93, the volume ratio of pre-adding water and TiOSO₄ solution is 0.28׃1, the optimum heating rate is 0.94−1.33 ℃/min and pH of the pre-adding water should be at near-neutral range.

A new solution called component modification in-process was introduced to the difficult grinding of air quenching steel slag by a series of experiments. The results show that the fly ash added into the molten steel slag before air quenching can more effectively improve the slag’s grindability than milltailings, which is the other modification agent tested under the same conditions. The role of fly ash is strengthened as its proportion increases, although the degree of promotion is gradually reduced. As a result of the reaction between fly ash and steel slag at high temperature, some new mineral phases and vitreous bodies with fine grindability promote the slag grinding easily. This work is helpful to making a comprehensive utilization of steel slag and maximize its economic efficiency in China.

Batch and column experiments were conducted to determine whether zerovalent iron (ZVI) and sulfate reducing bacteria (SRB) can function synergistically and accelerate pollutant removal. Batch experiments suggest that combining ZVI with SRB can enhance the removal of U(Ⅵ) synergistically. The removal rate of U(Ⅵ) in the ZVI+SRB combining system is obviously higher than the total rate of ZVI system and SRB system with a difference of 13.4% at t=2 h and 29.9% at t=4 h. Column experiments indicate that the reactor filled with both ZVI and SRB biofilms is of better performance than the SRB bioreactor in wastewater basification, desulfurization and U(Ⅵ) fixation. The results imply that the ZVI+SRB permeable reactive barrier may be a promising method for treating subsurface uranium contamination.

The adsorption of biopesticide avermectins onto activated carbon from ethanol solution with different initial concentrations at 303.15 K was performed. The obtained equilibrium and kinetic data of the adsorption process were assayed to evaluate the adsorption potential of activated carbon for avermectins. The results show that the activated carbon is effective for the adsorption of avermectins. Moreover, the adsorption of avermectins onto activated carbon agrees with Langmuir isotherm model, while pseudo-second-order kinetics model is better fitable for such adsorption process. In addition, activated carbon can efficiently protect adsorbed avermectins from photodegradation.

The systematic science of alloys (SSA) is a framework of the total energy and total volume able to be separated. The volume sequences of characteristic atoms at the central sites of the basic clusters in the fcc-based Au-Cu system are separated out from the experimental volumes of L1₀-AuCu and L1₂-AuCu₃ compounds at room temperature only, by nine volume V-functions. From these volume sequences, the volumes, volumes of formation, ordering (excess) volumes and volume mismatch degrees of the L1₀-AuCu, L1₂-AuCu₃ and L1₂-Au₃Cu compounds, Au₃Cu-, AuCu- and AuCu₃-type ordered alloys with maximal ordering degree, and disordered Au_1−xCu_x alloys are calculated. Among these functions, only ordering volumes of the compounds and ordered alloys obtained by the 6th V-function are negative, i.e., the destruction of the superlattice is accompanied by an increase in volume, which is identical with the experimental results. Accompanying conclusions, the different descriptions of volumetric properties between traditional alloy theories and SSA framework are discussed.

The crystallization kinetics of the bulk amorphous Cu_58.1Zr_35.9Al₆ alloy was examined by differential scanning calorimetry under continuous heating and isothermal annealing. During continuous heating, the activation energy of crystallization was determined to be 383 kJ/mol by Kissinger method. However, on the isothermal annealing, the activation energy was determined to be 459.2 kJ/mol by the Arrhenius method, which was much larger than that obtained from the Kissinger method. The different temperatures at which crystallization occurs are responsible for the discrepancy in the activation energy. The average Avrami exponent of about 3.5 implies that the crystallization process of the bulk amorphous Cu_58.1Zr_35.9Al₆ alloy is diffusion-controlled with a nucleation rate decreasing with time.

A series of solid solutions Er₂W_3−xMo_xO₁₂ (0.5≤x≤2.5) were successfully synthesized by the solid state method. Their crystal structures and negative thermal expansion properties were studied by high temperature X-ray powder diffraction and the Rietveld method. All samples with rare earth tungstates and molybdates crystallize in the same orthorhombic structure with space group Pnca, and show the negative thermal expansion phenomena related to transverse vibration of bridging oxygen atoms in the structure. Thermal expansion coefficients (TECs) of Er₂W_3−xMo_xO₁₂ were determined as −16.2×10⁻⁶ K⁻¹ for x=0.5 and −16.5×10⁻⁶ K⁻¹ for x=2.5 while −20.2×10⁻⁶ K⁻¹ and −18.4×10⁻⁶ K⁻¹ for unsubstituted Er₂W₃O₁₂ and Er₂Mo₃O₁₂ in the identical temperature range of 200−800 ℃. High temperature XRD data and bond length analysis suggest that the difference between W−O and Mo−O is responsible for the change of TECs after the element substitution in the series of solid solutions.

In order to study the spectroscopic properties of vacancies and trap levels in Lu₃Al₅O₁₂׃Ce³⁺ (LuAG׃Ce³⁺) crystal, the <111>-oriented LuAG׃Ce³⁺ crystal grown in pure nitrogen atmosphere by Czochralski method was annealed in oxidizing atmosphere (air) and reducing atmosphere (H₂+N₂), respectively. The excitation and emission spectra of LuAG׃Ce³⁺ crystal after different thermal annealing treatments were measured in the temperature range of 8−450 K, and the thermally stimulated luminescence curves of LuAG׃Ce³⁺ crystal were characterized. It is found that the oxygen vacancies in LuAG׃Ce³⁺ crystal are effectively eliminated through the annealing treatment in air and four trap levels are observed in as-grown LuAG׃Ce³⁺ crystal with temperature position peaking at 110, 210, 325 and 475 ℃, respectively.

The spontaneous polarization in ferroelectric (FE) nanowires (NWs) can be considerably enhanced due to the nanosize confinement by the first-principles calculations. The spontaneous polarization in a fully-relaxed BaTiO₃ NW with 2.0 nm in diameter is 1.18 times higher than that of bulk counterpart. The ferroelectric properties of the wire are found to generally depend on its dimensions through effects of the surface tension and near-surface depolarizing effect. The surface tension seems to be crucial for the giant enhancement of spontaneous polarization.

Quantum chemical calculation was used to estimate the reduction potentials of 25 organic cations and the oxidation potentials of 11 anions. This information was used to select promising cations and anions for the preparation of ionic liquids as green electrolytes for electrodeposition of active metals. The reasonable linear correlations between the lowest unoccupied molecular orbital (LUMO) energies and the reduction potentials of cations, and the linear relationships between the oxidation potentials and the highest occupied molecular orbital (HOMO) energies of anions were obtained. The orders of electrochemical stability for cations and anions being obtained agree well with the experimental measurements. The suitable ionic liquids with sufficiently wide electrochemical windows for electrodeposition of active metals are suggested to be [Emim]NTf₂, [Bmim]NTf₂, [Bmim]BF₄, [Bmim]PF₆, [Bmim]CTf₃, [Emim]BF₄, [Emim]PF₆, [Emim]CTf₃._.

The energy transportation and accumulation effect for femtosecond (fs) laser ablation on metal targets were studied using both theoretical and experimental methods. Using finite difference method, numerical simulation of energy transportation characteristics on copper target ablated by femtosecond laser was performed. Energy accumulation effects on metals of silver and copper ablated by an amplified Ti: sapphire femtosecond laser system were then studied experimentally. The simulated results show that the electrons and lattices have different temperature evolvement characteristics in the ablation stage. The electron temperature increases sharply and reaches the maximum in several femtoseconds while it needs thousands of femtoseconds for lattice to reach the maximum temperature. The experimental results show that uniform laser-induced periodic surface structures (PSS) can be formed with the appropriate pulsed numbers and laser energy density. Electron-phonon coupling coefficient plays an important role in PSS formation in different metals. Surface ripples of Cu are more pronounced than those of Au under the same laser energy density.

With applied dislocation theory, the effects of shear and normal stresses on the slide and climb motions at the same section of a crystal were analyzed. And, based on the synergetic effect of both normal and shear strain specific energies, the concept of the total equivalent strain specific energy (TESSE) at an oblique section and a new strength theory named as limiting strain energy strength theory (LSEST) were proposed. As for isotropic materials, the plastic yielding or brittle fracture of under uniaxial stress state would occur when the maximum TESSE reached the strain specific energy, also the expressions on the equivalent stresses and a function of failure of the LSEST under different principal stress states were obtained. Relationship formulas among the tensile, compressive and shear yield strengths for plastic metals were derived. These theoretical predictions, according to the LSEST, were consistent very well with experiment results of tensile, compressive and torsion tests of three plastic metals and other experiment results from open literatures. This novel LSEST might also help for strength calculation of other ma, terials.