The solution of surface displacement of an elliptical crack under compressive-shear loading was obtained by using the complexfunction method. The closing mode was established by analyzing the geometrical condition of closing crack, and the corresponding critical stress wassolved. The result corrects the traditional viewpoint, in which there exist only open or close states for an elliptical crack, and points out that the local closingis also one of crack states. Based on them, the effect of the closed crack on stress intensity factor was discussed in detail, and its rational formulae are put forward.

In continuous casting rolling process, the deformed body is different from the hot rolling strip. The metal in casting rolling zone is first assumed to be viscous fluid and the mathematical model of casting rolling force is established, then the calculating formula for casting rolling torque is derived. In addition, considering the effects of deforming cone and appendant torque of rotary junction＇s sealing ring, the calculating model which accords with casting rolling condition is found out. Theoretical formula is proved by experiment. 

It is important to depress diaspore effectively in order to remove silicates from diasporic bauxite. A new water soluble polymer hydroxamic acid starch (HA-starch) was prepared. The effects of the product on the diaspore and kaolinite flotation were investigated and its reactive mechanism was studied by zeta potential measurement and FTIR. The results show that HA-starch can depress diaspore while make positive effect on kaolinite flotation at low pH value(pH below 6). The flotation recovery of diaspore was sharply decreased with the increase of concentration of HA-starch. The chemical adsorption of HA-starch on the surface of diaspore was revealed.

Quartz is the main gangue mineral of sillimanite. The results show that Al³⁺ and Fe³⁺ ion can activate the floatation of quartz and make the separation of quartz and sillimanite difficult when anion collector is used, and citric acid can inhibit the quartz activated by metallic ion and have slight influence on the sillimanite. X-ray photoelectronic energy spectrum analysis indicates that there are obvious electronic energy peaks on the surface of the quartz before citric acid is added into the ore pulp in presence of Al³⁺ and Fe³⁺, and after citric acid is added, the energy peak vanished. So citric acid can make Al³⁺ and Fe³⁺ on the surface of quartz solve and decrease the active points on the surface of quartz which can adsorb anion collector.

Pyrite cinder is a kind of solid waste of sulfuric acid industry. After mixing pyrite cinders with sulfuric acid, ferric sulfate was obtained by heating, maturing, dissolving and filtrating. Suitable amounts of FeSO₄·7H₂O and NaClO₃ were added into ferric sulfate solution and polyferric sulfate(PFS) solution was produced. Solid PFS was made by concentrating and drying PFS solution. Time-dependent complex colorimetric tests were done while ferron agent reacted with Fe³⁺ in the solution. The results show that the proportion of transitional low polymeric species and high polymeric species are increased after PFS solution is transferred into solid PFS. It was discovered by jar tests that solid PFS has very good coagulation effects relevant to the increase of transitional lower polymeric species.

The gas-liquid equilibrium and evaporation behaviors of HCl and H₂O in the distillation process of the BiCl₃-HCl-H₂O ternary system were investigated. With increasing content of BiCl₃, the quasi-azeotropic point moves toward the low acidity and high temperature. The evaporation law of HCl and H₂O in low-acidity BiCl₃ solution was summarized. The residue phases were studied as well. The results show that the residue phases vary with the distillation temperature, namely BiCl₃ and (BiCl₃·xHCl) at low temperature and BiCl₃ and BiOCl exist at higher temperature. The causes for the formation of different residue phases were discussed.

Influence of supersaturation on the structure of a series of freshly prepared supersaturated sodium aluminate solutions with medium concentration was investigated by solution X-ray diffraction. Experimental results show that the basic Al-containing species in all kinds of supersaturated solution is four-coordinated ions. Opposite to Al—O distance contracted in highly concentrated solution, a little expand of the Al—O distance from 1.75℃ to 1.85℃ occurs with increasing supersaturation, which is consistent with the occurrence of oligomeric aluminate species. Meanwhile, O—O distance in the first shell of H₂O—H₂O(OH) in supersaturated sodium aluminate solution is obviously longer than in hydroxide sodium solution and becomes longer and longer with increasing supersaturation. Na—O bond length is about 2.4℃ and changes little with supersaturation. The reason for Al—O bond expanding with supersaturation and its influence on the stability of solution was discussed. 

A novel type of thermal stabilizers—antimony tris(mercaptoethyl carboxylates) (Sb(SCH₂CH₂OOCR) ₃), was synthesized from carboxylic acid, antimony trioxide and 2-mercaptoethanol in two steps. The experimental results show that the molar ratio of carboxylic acid to antimony tris(2-hydroxyethyl mercaptide) is 1.2, when adding 0.6% tetra-n-butyl titanate as catalyst and xylene as isotropic solvent, heating and refluxing for about 2~4h. The thermal stability was measured by heat-aging oven test. The thermal stability time is about 8~40min(at 200℃) when adding 2% tetra-n-butyl titanate in polyvinyl chloride(PVC). Among these stabilizers, antimony tris(mercaptoethyl stearate) has best thermal stability. Its thermal stability is better than that of Ca-Zn complex and basic lead stabilizers, and equal to that of organotin. In addition, the stabilization mechanism of this kind of stabilizers for PVC was discussed briefly.

Two possible structures of Mo₈O₂₆^4-) were optimized using the Polak-Ribiere method of Molecular Mechanics Optimization and the termination condition is RMS (Root-mean-square) gradient of 0.42kJ/mol. Based on the calculations of the molecular dynamics, Lengevin dynamics and Monte Carlo dynamics simulation, the structure models of Mo₈O₂₆^4- with the lowest energy were acquired respectively according to the energy of the systems calculated using the ZIDO/1 and PM3 methods. The total energy, energies of some frontier molecular orbitals and atomic charges of Mo₈O₂₆^4－ were computed at the HF/3-21G and HF/STO-3G levels. The calculation results show that the contortion of the structure with eight MoO₆ is smaller than that of the structure with six MoO₆ and two MoO₄. The total energies of the two structures are nearly equal because the contortion of the structure with six MoO₆ and two MoO₄ would make the exclusion force decreased.

Electroreduction of Co(Ⅱ) to metallic Co in acetamide-urea-NaBr melt at 353K is irreversible in one step. Gd（Ⅲ) is not reduced to Gd alone, but can be inductively codeposited with Co(Ⅱ). The amorphous Gd-Co alloy films were obtained by potentiostatic electrolysis. With the cathode potential shifting to negative direction, the content of gadolinium in the alloy increases and can get to 65.89% (mass fraction). The additive of Na₂EDTA can make the diameter of the particles of crystalline alloy smaller and change the shape of particles. 

The effects of Cu (Ⅱ) or Zn (Ⅱ) on the photo-catalytic degradation of some organic chemicals in water, such as acetone, phenol, dyes, and tea saponin were studied. Dyes in wastewater from a textile factory can be effectively degraded by photo-catalysis with TiO₂ and ultraviolet light or sunshine, but the reaction rate could be slowed down if copper or zinc salt exists in the solution.