In order to study the structure transition during calcination, nano-titania powders prepared by hydrolyzing precipitation approach and calcined at 300, 400, 500, 600 and 700 °C were characterized by XRD, TEM and electron diffraction (ED), respectively. The results show that titania powders calcined below 500 °C are almost composed of anatase, rutile appears below 500 °C and its ratio increases gradually with increase of calcin temperature; nano-titania particles are smaller than 40 nm mostly and the dispersion is related to calcining temperature; the interplanar distances of nano-anatase single crystalline change gradually when calcing temperature increases to 500 °C; so do that of nano-rutile single crystalline when calcining temperature charges from 600 to 700 °C. The conclusions can be drawn that the temperature of transformation from anatase to rutile is below 500 °C and the process carries on gradually. Both inter-planar distances and the structure of nano-titania transform gradually with increasing calcing temperature.

The crystallization kinetics of amorphous Nd_3.6Pr_5.4Fe₈₃Co₃B₅ and the preparation of α-Fe/Nd₂Fe₁₄ B nanocomposite magnets by controlled melt-solidification of Nd_3.6Pr_5.4Fe₈₃Co₃B₅ was investigated by employing DTA, XRD, and TEM. The results show that a metastable intermediate phase Nd₈Fe₂₇B₂₄ prior to α-Fe and Nd₂Fe₁₄B phases is crystallized as the amorphous Nd_3.6Pr_5.4Fe₈₃Co₃B₅ is heated to 1 223 K. The crystallization activation energy of α-Fe and Nd₈Fe₂₇B₂₄ phases is larger at the beginning stage of crystallization, and then it decreases with crystallized fraction x for the former and has little change when x is below 70% for the latter, which essentially results in an α-Fe/Nd₂Fe₁₄B microstructure with a relatively coarse grain size about 20–60 nm and a non-uniform distribution of grain size in the annealed alloy. The α-Fe/Nd₂Fe₁₄B nanocomposite magnets with a small average grain size about 14 nm and a quite uniform grain size distribution were prepared by controlled melt-solidification of Nd_3.6Pr_5.4Fe₈₃Co₃B₅ at a wheel speed of 20 m · s⁻¹ during melt-spinning. The magnets show a high maximum energy product of (BH)max=194 kJ · m⁻³, which is nearly twice of that of the nanocomposite magnets made by annealing the amorphous Nd_3.6Pr_5.4Fe₈₃Co₃B₅ precursor alloy.

Thermodynamic properties and electrochemical behaviors of gold and its associated elements, such as silver, copper, nickel and iron, in various complex agent solutions were studied. Within CS(NH₂)₂, S₂O₃²⁻ and SCN⁻ systems, alkaline thiourea is the optimal nontoxic lixiviating agent substituting cyanide from the viewpoint of thermodynamics. The electrochemical study indicates that the anodic dissolution current densities of gold are 2.616, 1.805, 1.267, 1.088, 0.556, and 0.145 mA · cm⁻² respectively in the solutions of cyanide, alkaline thiourea containing Na₂SiO₃, SCN⁻, acidic thiourea, alkaline thiourea and thiosulfate at the potential of 0.500 V. Comparing various lixiviating agents, the alkaline thiourea solution containing Na₂SiO₃ is of prominent selectivity in leaching gold, in the potential range from 0.500 to 0.600 V, which is most efficient for leaching gold selectively instead of cyanide. The effect on leaching gold is similar to that in the cyanide system.

Na₂SiO₃ and Na₂SeO₃ were chosen as stable reagents of alkaline thiourea solution substituting Na₂SO₃, according to the structure-property relationship between the stability of alkaline thiourea and the structure of thiourea and sulfite ion, and the effect of the stable reagents on stability of alkaline thiourea was investigated. The results show that contrary to Na₂SeO₃, Na₂SO₃ and Na₂SiO₃ affect the stability of alkaline thiourea solution remarkably. The stable effect of Na₂SiO₃ on alkaline thiourea is obviously better than that of Na₂SO₃. The stable reagents Na₂SO₃ and Na₂SiO₃ decrease the decomposition rate of alkaline thiourea solution greatly, and the decomposition rate of alkaline thiourea reduces from 72.5% to 33.8% with addition of 0.3 mol · L⁻¹ Na₂SiO₃. Dissolution currents of gold in the alkaline thiourea solution containing Na₂SO₃ and Na₂SiO₃ are 2.0 mA · cm⁻² and 3.5 mA · cm⁻² at the potential of 0.42 V, respectively, and Na₂SO₃ is consumed excessively due to the oxidation reaction of Na₂SO₃ occurring in the studied potential range. Na₂SiO₃ is an efficient stable reagent of alkaline thiourea solution, and gold dissolution is accelerated much more obviously by Na₂SiO₃ than by Na₂SO₃.

Scheelite and scheelite-wolframite mixed concentrates with different grades were decomposed by caustic soda digestion, and the effects of caustic soda (NaOH) dosage, the ratio of water to ore and the stirring rate on tungsten recovery were studied. The results show that under the conditions that the ratio of water to ore is 0.8, stirring rate is 500 r · min⁻¹ and the heating time is 2.0 h at 160 °C, the recovery of tungsten reaches 98% for scheelite (w(WO₃) is 65.04%) and wolframite containing high proportion of calcium (w(WO₃) is 65.58%, w(Ca) is 7.53%), when caustic soda dosage is 2.2 and 2.0 times of theoretical value, respectively; the recovery of tungsten can be more than 98%, 98% and 96% respectively for low-grade scheelite-wolframite mixed concentrate with 55.78%, 45.32% and 25.21% WO₃, when caustic soda dosage is 2.6, 3.2 and 5.5 times of theoretical value, respectively.

Thermo-gravimetric analyzer (TGA) was used to determine the thermal behavior of stainless steelmaking dust and FTIR was used to detect the components of off-gas. The TGA results indicate that three mass loss/gain stages exist in the thermal process. The mass loss of the dust in the first stage results from the evaporation of moisture and the reaction between dissociated carbon and metal oxides in the dust. The evaporation of moisture within the dust happens at 90–350 °C and the formation of carbon dioxide happens at 250–470 °C. The mass gain of the dust in the second stage results from the oxidation of metals in the dust by the oxygen at 470–950 °C. The third stage is a slow mass loss process, and some metals in the dust are evaporated into the atmosphere in this stage. The evaporation of metals is carried out mainly at 900–1200 °C and the dust is sintered at high temperature over 1200 °C.

In recovering Ge and Ag from the calcine and fume dusts mixture of Huidong Lead-zinc Mine, the flow sheet of hot acid leaching-halotrichite method mainly consists of neutral leaching, low-acid leaching, high acid leaching and jarosite precipitation. In the ten circulation periods, the technology flow sheet was carried out smoothly. The loss of Ge in halotrichite residue is less than 5.0%, when iron is precipitated by using ferric potassium alum instead of common Na or ammonium alum and the conditions are controlled at temperature about 95 °C for more than 3 h, pH values below 1. 5. Ge and Ag are concentrated in the high acid leached residue, and their contents are 0.032% and 0.162%, respectively, and the total recovery and direct recovery of zinc are 98.94% and 96.15%, respectively.

A novel technology for lead removal with nonliving Rhizopus oligosporus immobilized in calcium alginate was studied. The results show that the main influencing factors include pH value and interfering cations. pH value has different effects on biosorption of various heavy metals and lead adsorption can be proceeded by controlling pH value in a range of 2–5; interfering cations especially Cu(II) can make the adsorption amount of Pb(II) decrease by immobilized Rhizopus oligosporus. Desorption efficiency of different eluants and kinetics were investigated. Citrate acid with concentration of 0.3 mol · L⁻¹ is the best for the elution of Pb(II) and desorption rate is over 98% when the reaction equilibrium reaches 3 h. Immobilized biomass keeps high lead biosorption capacity after five cycles of regeneration.

Based on the theoretical analyses, the adhesion process of fine gold particles to oil-carbon agglomerates in a dynamic system was quantitatively investigated in terms of the relationship between the attachment probability and the surface energy. The proposed way to establish this relationship is to firstly theoretically derive the formula to evaluate the surface energy change of the system by analyzing the adhesion process of a gold particle on an oil-carbon agglomerate in a mathematic and thermodynamic way. The obtained formula of the maximum energy change of unit surface area is, Δw′_max=1/2σ_hw(cos ϑ−1), which involves two measurable elements: interfacial tension and contact angle. In a well-quantified system, based on the related model it is also possible to calculate the complicated concept, namely, the attachment probability by transferring other measurable indices. In this way, after some adhesion experiments and measurements of relevant parameters, the empirical relationship between the attachment probability and the surface energy change was established in an exponential function, P_a=Aexp(−ΔG_surf/k).

Using cetyl trimethylammonium bromide (CTAB) as collector, the flotation de-silicating from diasporicbauxite was investigated. And the Zeta potentials and contact-angles of silicate minerals and diaspore were also studied. The results show that in the presence of 2×10⁻⁴ mol·L⁻¹CTAB, the surface charges of pyrophyllite, kaolinite and illite become more positive, and the contact angles of these three silicates also increase evidently in the pH range of 2–8, but the Zeta potentials and contact angles of diaspore change little. So, the floatability of the four minerals is in the following order: pyrophyllite>kaolinite∼illite>diaspore. The open-circuit flotation results also show that a bauxite concentrate with m(Al₂O₃)/m(SiO₂) over 9.3 and Al₂O₃ recovery over 76% can be obtained from diasporic-bauxite ore. The result of XRD of the bauxite concentrate shows that pyrophyllite is easier to be removed from diasporic-bauxite than illite and kaolinite due to its better floatability.

The flotation behavior of quartz using N-(2-aminoethyl)-octadecanamide (AEOA) as a collector was investigated. Zeta potential and infrared spectra were conducted to investigate the mechanism of the interaction of the quartz surface with the collector molecules. The results show that electrostatic force and hydrogen bond play an important role in governing the mechanism of flotation in acidic and alkaline media. The recoveries of quartz are 99.0%–99.8% in the pH range of 3–11. The recovery of quartz is less dependent on AEOA concentration, mainly due to the formation of micellae in aqueous solution, and the adsorption density of AEOA on the quartz surface nearly remains constant.

The shock wave compression behavior of the open cell aluminum foam with relative density of 0.396 was studied through planar impact experiments. Using polyvinylidene fluoride (PVDF) piezoelectric gauge technique, the stress histories and propagation velocities of shock wave in the aluminum foam were measured and analyzed. The results show that the amplitude of shock wave attenuates rapidly with increasing the propagation distance in the aluminum foam, and an exponential equation of the normalized peak stress vs propagation distance of shock wave is established, the attenuation factor in the equation is 0.286. Furthermore, the Hugoniot relation, v₅=516.85 + 1.27v_p, for the aluminum foam is determined by empirical fit to the experimental Hugoniot data.

A symmetrically alternative rotating flow pattern was designed for flocculation process in order to produce large and dense flocs. The special effects of a symmetrically alternative rotating flow on the diameter and density of flocs were investigated. The results show that under the new fluid conditions, the primary particles on the outer part of the formed flocs may be cut down and the flocs contract at the end of the original rotating direction; then fluid changes its rotating direction, an opposite shearing is imposed to the flocs and makes some primary particles slide along the floc surface, leading to a denser floc; meanwhile, the broken and unflocculated particles on the trajectory may have opportunities to penetrate into or cohere to the flocs. Compared with the conventional rotating flow, the new-designed flow pattern can not only keep the floc size (even enlarge the floc diameter if a suitable flow is chosen) but also increase the floc density effectively.

Light conversion agents Eu_1−xL_x(TTA)₃Phen (L denotes La³⁺, Gd³⁺, Y³⁺) complexes were prepared, and the influence of doping ions on fluoresence properties was investigated by elementary analysis, FTIR and fluorescent spectra. The results show that FTIR spectra of Eu_1−xL_x(TTA)₃Phen complex system are identical with that of EuTTA₃Phen, which indicates that the complexes Eu_1−xL_x(TTA)₃Phen are similar in structure to Eu (TTA)₃Phen. For the above doping elements, co-fluorescence enhancement has the following order: Gd³⁺ > Y³⁺>La³⁺, and the optimum mole fractions of doping elements are 0.4, 0.2 and 0.5 respectively for Gd³⁺, Y³⁺, La³⁺. Among all the complexes, Eu_0.6Gd_0.4(TTA)₃Phen complex has the strongest fluorescent intensity. Applying Eu_0.6Gd_0.4(TTA)₃Phen complex to plastic and printing inks, bright red fluorescence plastic and printing inks are obtained when the content of europium reaches 0.1% (mass fraction).

The unsaturated quaternary ammonium salt diethyladiallylammonium chloride(DEDAAC) was synthesized in a two-step synthetic method. The influences of the adding method of raw materials and temperature on the yields of diethylallylamine (DEAA), and drying and temperature on the synthesis of DEDAAC were investigated. The content of in-process product DEAA was determined by non-aqueous titration. The structure of product DEDAAC was identified with IR, ¹H NMR and elemental analysis. The results show that adding allyl chloride and sodium hydroxide alternately can increase the yield of DEAA and decrease by-products. In further synthesizing of DEDAAC from DEAA, the step of drying DEAA is very necessary. When DEAA is dried by solid sodium hydroxide, good columnar crystals with a high purity(mp 199.5–201.0 °C) are obtained; when DEAA is undried or the content of water in DEAA is above 2%, only platelets with bad quality are obtained even without crystals. The suitable synthesis conditions for DEAA and DEDAAC are 35 °C, 6 h and 40 °C, 36 h, respectively, and their yeilds are 69.7% and 67.3%, respectively.

Shaxi porphyry Cu-Au deposit was one of the important discoveries of the exploration in the middle-lower reaches of Yangtze River in China in 1970’s. Gold occurrence in the Shaxi porphyry copper-gold deposit (central Anhui province, eastern China) was investigated by means of microscope analyses, EPMA and PIXE. Combined with geological and mineralogical methods, the characteristies of occurrence of gold in the large scale sulfide mineralization in this region were fully investigated. The results show that gold distributes in both chalcopyrite and pyrite as submicroscopic inclusions (less than 1 µm). Au is positively correlated with As, Fe, S, Cu, Zn and Ti. The condition of gold transformation in thermal fluid system controlling deposition of Au in the region is probably the oxidation potential of the red sedimentary rocks of shale and fine grain sandstone which may be crucial as a geochemical barrier to the reducing fluid. This study lays foundation for the further research and exploration of the porphyry copper-gold deposit both theoretically and practically in the lower reaches of Yangtze region.

A new searching algorithm named the annealing-genetic algorithm (AGA) was proposed by skillfully merging GA with SAA. It draws on merits of both GA and SAA, and offsets their shortcomings. The difference from GA is that AGA takes objective function as adaptability function directly, so it cuts down some unnecessary time expense because of float-point calculation of function conversion. The difference from SAA is that AGA need not execute a very long Markov chain iteration at each point of temperature, so it speeds up the convergence of solution and makes no assumption on the search space, so it is simple and easy to be implemented. It can be applied to a wide class of problems. The optimizing principle and the implementing steps of AGA were expounded. The example of the parameter optimization of a typical complex electromechanical system named temper mill shows that AGA is effective and superior to the conventional GA and SAA. The control system of temper mill optimized by AGA has the optimal performance in the adjustable ranges of its parameters.

In order to know the ventilating capacity of imperial smelt furnace (ISF), and increase the output of plumbum, an intelligent modeling method based on gray theory and artificial neural networks (ANN) is proposed, in which the weight values in the integrated model can be adjusted automatically. An intelligent predictive model of the ventilating capacity of the ISF is established and analyzed by the method. The simulation results and industrial applications demonstrate that the predictive model is close to the real plant, the relative predictive error is 0.72%, which is 50% less than the single model, leading to a notable increase of the output of plumbum.

Based on the definition of component ontology, an effective component classification mechanism and a facet named component relationship are proposed. Then an application domain oriented, hierarchical component organization model is established. At last a hierarchical component semantic network (HCSN) described by ontology interchange language (OIL) is presented and then its function is described. Using HCSN and cooperating with other components retrieving algorithms based on component description, other components information and their assembly or composite modes related to the key component can be found. Based on HCSN, component directory library is catalogued and a prototype system is constructed. The prototype system proves that component library organization based on this model gives guarantee to the reliability of component assembly during program mining.

The conventional complete association rule set was replaced by the least association rule set in data warehouse association rule mining process. The least association rule set should comply with two requirements: 1) it should be the minimal and the simplest association rule set; 2) its predictive power should in no way be weaker than that of the complete association rule set so that the precision of the association rule set analysis can be guaranteed. By adopting the least association rule set, the pruning of weak rules can be effectively carried out so as to greatly reduce the number of frequent itemset, and therefore improve the mining efficiency. Finally, based on the classical Apriori algorithm, the upward closure property of weak rules is utilized to develop a corresponding efficient algorithm.