In this paper, 2201 and 2212 phases as the corresponding precursor of forming 2212 and 2223 phases are discussed, and the constructive process of unit cell of 2201 phase is ascertained by XRD and chemical kinetics method. Subsequently, the process of 2212 and 2223 phases is described by analyzing the order of CuO₂ and CaO planes entering in terms of kinetics equation as well as apparent activation energy. In addition, the orientation for preparing 2223 single phase is explored.

The microstructures and elemental distribution of dense TiAl based alloy products produced by reactive-hot-pressing 1 : 1 Ti-Al blend powder were observed and analysed with scanning electron microscope (SEM). The four solid-state phases TiAl₃, TiAl, Ti₃Al andα-Ti were first formed in the original Ti particles through the reaction of Ti and Al according to the elemental distribution and their respective composition ranges. Then, the synthetic reactions continued among the four formed solid-state phases. With the diffusion and homogenization of elements, the formed TiAl₃ andα-Ti phases would disappear after further reacting. Finally, the microstructure consists of the two phases, TiAl and Ti₃Al.

Based on the one-dimension wave equation and multi-scale operator, the method of imaging of wave velocity is presented. Our method in this paper can suppress the noise in the real world data, and analyse the effects of the hand-limited data in frequence. Then, the nonlinear high-frequency integral equation is given.

Based on physicochemical study of the reaction between scheelite and NaOH, a new decomposition process for scheelite and scheelite-wolframite concentrate, i. e., mechenically activating caustic decomposition has been developed, and it has been successfully used on a commercial scale in 11 tungsten plants in our country. Industrial practice has shown that a tungsten recovery higher than 98% for sheelite concentrate and 99% for scheelite-wolframite mixed concentrate is obtained, under the conditions of NaOH/WO₃ mole ratio of 3.6–4.8, 160–170 °C, and it is suitable to treat almost any sort of tungsten ore concentrates, including low grade complex concentrate, and it is more effective than the traditional soda ash digestion process.

The research of recovering WO₃ from ammonia leaching slag in the extractive process of tungsten has been performed. The results show that the mechanically activated decomposition with Na₂CO₃ for ammonia leaching slag is feasible. After the treatment of ammonia leaching slag containing WO₃ 10%, the content of insoluble WO₃ in residue is 1%–2% and the tungsten recovery is 81%–90% when the total amount of Na₂CO₃ and NaOH is 4 times of their theoretical value and the slag is kept for 2 hours at 190 C. The obtained Na₂WO₄ solution can satisfy the requirements of subsequent production process after purification.

The technology of coal-based direct reduction of high-iron-content red mud is studied. The factors affecting this kind of direct reduction mainly are: coal sort, carbon amount, time, temperature and etc. has been investigated. It has been shown that an ideal coal sort must have the following qualities: high reactivity, large ratio of (F_c +V_m)/A and (SiO₂ +T_Fe)/(Al₂O₃ + Others) and the ability of forming a moderate porosity.

This paper presents a conception of Preventive-Predictive Maintenance, describes a living instance which combines the technology of equipment condition supervising and failure diagnosing with the system of computer aided equipment management, and then establishes a system of equipment preventive-predictive maintenance which has the important practical significance to modern equipment management.

The stress intensity factorK in the tip of crack which is in the corner of the frame component has been calculated indirectly by means of numeric calculation ofJ Integral. Some laws and relationships among the stress intensity factorK, the applied loads and the crack length for this kind of components have been discovered for the first time. The calculating formula forK has been deduced, the criticalK has been calculated with the formula, that is 5 811.56–6 122.58 MPa · mm^1/2. The conclusions reached in this paper are of great referential and practical value for simplifying the calculation of stress intensity factorK for this type of components.

The cupreous porphyries occurring in Shanyang District, Shanxi Province, were geotectonically developed in Qinling orogenic belt during Yenshan epoch. Their K/Na=0.84–2.74,δ = 2.48–3.70, DI = 70.19–80.69,δEu≈1,δ³⁴S is approximately consistent with that of the meterorite, lead isotope leadμ=9.03–9.42. All of the petrochemistry characteristics show that those porphyries are anatectic syntectic (I-type) granites formed in the intracontinental subduction belt, and the granites are favourable for forming the porphyry copper deposit.

In view of DC speed control system, this paper presents a predictive control algorithm to replace traditional PID control. System predictive model requires little information of the controlled object, and because it adopts rolling optimum method, system possesses excellent dynamic and static performance. According to the practice results, it owns outstanding speed regulating and tracking property. Full digital system hardware improves system reliablity and it is easy to be adjusted. To reduce CPU’s complex calculation, we have studied and developed a digital hardware trigger. The trigger’s identical waveform and steady trigger pulse greatly facilitates system design work and improves system’s overall quality of antidisturbance. This device surely owns a prosperous prospect.

The paper describes a new method of the stepping motor minimun time optimal control with closed-loop control. A mathematical model and optimal control strategy for the optimal control of stepping motor are proposed. Realizing technology for accelerating starting duration and the highest speed running duration as well as decelerating and stopping duration is discussed. Hardware and software of the system are given by adopting single-chip processor. Applications in digital machines have shown that the optimal control described in the paper has good control performance.

This paper deals with the mechanics problem of dynamic walking of anthropomorphic biped robots. Through analysing the mechanics system of this kind of robots in detail, the motion constraint equations are established, three mechanics laws describing the relationships among the external forces are obtained, and the approaches to measuring and computing these forces using the pressure sensors are proposed. The results not only reveal the mechanics characteristics of dynamic walking of anthropomorphic biped robots but also are of an important significance in realizing the on-line computation and real-time control of their dunamic walking.

The charge distribution of ions in sillimanite crystal, diatomic energy, and the heat of absorption of sillimanite on collectors such as sodium oleate, sodium dodecyl sulfonate, and tetradecyl amine are evaluated in the light of quantum chemistry CNDO/2 method. According to the calculating results, the bonding mechanism between mineral and collectors is analyzed. It is demonstrated that sodium oleate is adsorbed on sillmanite surface chemically; however, in the case of sodium dodecyl sulfonate, it is of physic-adsorption. At the same time a good prediction was made on the collective power of collectors as in the following order:sodium oleate>tetradecyl amine>sodium dodecyl sulfonate. This order has been confirmed by the testing results of flotation.

As a part of comprehensive utilization of concentrate linnaeite, this paper mainly discussed the theoretical bases and technical process conditions of separation of cobalt and nickel by two-section extraction with N₂₃₅ and extraction of copper with Lix984 after changing sulfate system containing cobalt into chloride one, and solved the difficulty of removing Mg²⁺. Pure CoCl₂ solution for preparation of cobalt soaps was produced in this way, and chemical products of copper and nickel such as CuCl₂ · 2H₂O,NiCl₂ · 6H₂O were by-produced. It has many advantages, such as fewer reagents, high recovery yield of metals. It is an economical way for comprehensively recovering valuable metals of concentrate linnaeite.

A logic fault tree of mine spontaneous combustion of sulphide ores was built by the fault tree analysis (FTA) based on a lot of mechanism investigation of sulphide ore spontaneous combustion in more than ten mines and review of a great amount of relevant literature. The fault tree is composed of 17 key contributory factors. After making a qualitative analysis of the fault tree, the minimum relevant factors for assessment of inherent self-heating potential and the optimal pathes for controlling fire were put forward. A mathematical model based on the heat transfer and diffusion theory is recommended to pre-estimate quantitatively the fire risk in field.

LetR be ans-unital ring, and we prove a commutativity theorem ofR satisfying the following conditions: (1) For eachx, y εR, there exist bounded positive integersk=k(x,y), s=s(x,y), t=t(x,y) (where, at least one ofk, s, t is not equal to 1) such that (xy)k=x^sy^t, (xy)k+1=x^s+1y^t+1; (2)N, the set of all nilpotent elements ofR, isp-torsion free, wherep is the L. C. M. (least common multiple) of allk, s, t.