The thermal barrier coatings with NiCrAlY alloy bonding layer, NiCrAlY-Y₂O₃ stabilized ZrO₂ transition layer and Y₂O₃ stabilized ZrO₂ ceramic layer are prepared on nickel alloy substrates using the plasma spray technique. The relationship among the composition, structure and property of the coatings are investigated by means of optical microscope, scanning electronic microscope and the experiments of thermal shock resistance cycling and high temperature oxidation resistance. The results show that the structure design of introducing a transition layer between Ni alloy substrate and ZrO₂ ceramic coating guarantees the high quality and properties of the coatings; ZrO₂ coatings doped with a little SiO₂ possesses better thermal shock resistance and more excellent hot corrosion resistance as compared with ZrO₂ coating materials without SiO₂; the improvement in performance of ZrO₂ coating doped with SiO₂ is due to forming more dense coating structure by self- closing effects of the flaws and pores in the ZrO₂ coatings.

The 2024/3003 aluminum gradient alloys are prepared by semi-continuous casting. The influences of throttle bore diameter of embedded nozzle and temperature of internal melt on composition distribution, macrostructure, hardness are analyzed, and the stability of gradient distribution of composition, macrostructure and hardness along the axial direction of the ingot is also studied. The results show that diffe-rent composition profiles can be achieved by adjusting the processing parameters; the volume fraction of inner alloy in the ingot can be increased by enlarging the throttle bore diameter and elevating the temperature of inner melt; quasi-steady solidification can be realized within 20 s during cast processing, and consistent quality ingot is obtained by controlling the casting speed and liquid height of inner melt.

Mechanical properties and tribological behavior of a novel cast heat-resisting copper based alloy are investigated. The corresponding properties of a commercial aluminum bronze C95500 (ASTM B30) are compared with the alloy. The results show that the alloy possesses better mechanical properties and tribological behaviors than that of C95500 at elevated temperature. The tensile strength, elongation and hardness at 500°C are 470MPa, 2.5% and HB220, respectively. The wear rate of the developed alloy at ambient and elevated temperature is about one-sixth and one-fortieth of that of C95500, respectively. The alloy is very suitable for ma-nufacturing heat-resisting and wear-resisting parts. Major strengthening mechanisms for the alloy are solution strengthening and the second phase strengthening.

The uniform experiment design is an effective way of optimizing technology scheme for refining the grain size during multistage deformation. In this paper, it is adopted to evaluate the effect of each technology parameter on final grain size of AISI H13 hot-work tool steel during multistage deformation. It has been verified that the technology scheme for refining the final grain size can be determined rapidly and efficiently with the aid of the uniform design. The results show that the deformation parameters and the intermission time after deformation of the first stage affect the final grain size remarkably. For AISI H13 hot-work tool steel, the final grain size can be refined notably when deformation parameters for the first stage are set as follows: a deformation temperature range of 1 025–1 085 °C; a true strain of above 0.26 and the interpass time between the first and the second stage of deformation less than 10 s.

A new method of extracting chlorogenic acid from flos lonicerae, and treating the materials with enzyme before being extracted by ethanol is developed, and the optimum conditions are also investigated in detail. Three important factors, enzyme dosage, treatment time and treatment temperature are adapted to optimize the extraction process. The experimental results show that the extract yield of flos lonicerae and chlorogenic acid can be obviously increased by the cellulase treatment, 61.5 mg chlorogenic acid is obtained from 1.00 g flos lonicerae at most. The optimal temperature of enzymatic treatment is 40–50 °C. Compared with the use of single cellulase, the combined treatment of cellulase and pectinase increase the extract yield obviously but fail to improve that of chlorogenic acid.

An improved ethylene blue method for determination of sulfide is developed. It has been adapted to a direct determination of sulfide by both common spectrophotometric method and total differential spectrophotometric method. In common spectrophotometric method, the calibration curve is A=1.69ρ+0.006 and the correlation coefficient is 0.9994. The apparent molar absorptivity is 5.42 × 10⁴ L·mol⁻¹·cm⁻¹ and calibration curve is liner when ρ is in the range of 0–0.9 mg·L⁻¹. In total differential spectrophotometric method, the calibration curve is A=9.25ρ + 0.004 and the correlation coefficient is 0.9996. The apparent molar absorptivity is 2.96 × 10⁵ L·mol⁻¹ L·mol⁻¹·cm⁻¹ and calibration curve is liner when ρ is in the range of 0–0.10 mg·L⁻¹. The sensitivity of this method is increased significantly compared with the former ethylene blue method. The speed of reaction is also faster than the former one. The limit of detection is found to be 1.0 ng·mL⁻¹ by both common spectrophotometric method and total differential spectrophotometric method. Ten replicate analyses of a sample solution containing 100 ng·mL⁻¹ sulfide give a relative standard deviation of 1.8%. The effects of various cations and anions on the determination of sulfide are studied and procedures for removal of interference is described. The method is used for the determination of sulfide in environment samples with satisfactory results.

In order to resolve how to mine under the condition of high stress with rockburst, this paper analyzes the law of rockburst, and considers that most of the rockbursts occur in the high stress area of stope. A method of rockburst forecast and its steps are given, and three different stages of rockburst are identified. Furthermore, this paper considers that blasting energy can effectively control rockburst by changing the characteristics of rock mass, which decreases the probability of rockburst happening. According to characteristics of rockburst, two feasible mining techniques under rockburst conditions are put forward, that is stoping-and-filling method, and sublevel caving method of mining without any sills in hanging wall.

This paper deals with the method of using quasi observation. In the paper a simple algorithm is developed for the adjustment computation with quasi observation at first. And then the ability of quasi observation to improve ambiguity search technique is studied in detail. The robustness of the method is also discussed. A method to determine the weight of quasi observation is proposed. The results show that a prior height can be taken as a quasi observation and used together with GPS observations. It can strengthen residual tests, especially in situation where there are fewer satellites in the sky. It also can change structure of incorrect solutions, which will theoretically make less incorrect solutions left in search space. At last the field tests are carried out to show that the proposed method is effective. The success rate of ambiguity resolution in the four field tests is improved significantly.

P_k|fix|C_max problem is a new scheduling problem based on the multiprocessor parallel job, and it is proved to be NP-hard problem when k⩾ 3. This paper focuses on the case of k=3. Some new observations and new techniques for P₃|fix|C_max problem are offered. The concept of semi-normal schedulings is introduced, and a very simple linear time algorithm Semi-normal Algorithm for constructing semi-normal schedulings is developed. With the method of the classical Graham List Scheduling, a thorough analysis of the optimal scheduling on a special instance is provided, which shows that the algorithm is an approximation algorithm of ratio of 9/8 for any instance of P₃|fix|C_max problem, and improves the previous best ratio of 7/6 by M.X. Goemans.

Previously, researchers raised the accuracy for a robot’s hand to track a specified path in Cartesian space mainly through increasing the number of knots on the path and the segments of the path. But, this method resulted in the heavier on-line computational burden for the robot controller. In this paper, aiming at this drawback, the authors propose a new kind of real-time accurate hand path tracking and joint trajectory planning method for robots. Through selecting some extra knots on the specified hand path by a certain rule, which enables the number of knots on each segment to increase from two to four, and through introducing a sinusoidal function and a cosinoidal function to the joint displacement equation of each segment, this method can raise the path tracking accuracy of robot’s hand greatly but does not increase the computational burden of robot controller markedly.

A new problem solving framework for group decision support system using layer model approach is proposed. This kind of framework includes four basic layers, namely, application layer, task layer, logical layer and physical layer. Based on indicating the respective meanings of those layers a task skeleton of group decision support system and a logical structure of group decision support system generator are put forward and discussed in detail. The framework provides theoretical guidance for developing group decision support system to lower systematic development complexity and support reuse of software.

Trial mountain climbing algorithm to solve the inverse kinematics problem of redundant manipulator is introduced, and a method of describing a numeral with a special numeration system is given to define the changed step of the trial mountain climbing algorithm. The results show that a likelihood solution can be found quickly in the infinite groups of likelihood solutions within the limited search times, and need not calculate the anti-trigonometric function and the inverse matrix. In addition, this algorithm has many good qualities such as concise algorithm, tiny computation, fast convergence velocity, good stability and extensive adaptability.

Let X and Y be real Banach spaces. The stability of Hyers-Ulam-Rassias approximate isometries on restricted domains S (unbounded or bounded) for into mapping f: S → Y satisfying | ‖ f(x) − f(y) ‖ − ‖ x − y ‖ | ⩽ εφ (x, y) for all x, y ε S is studied in case that the target space Y is uniformly convex Banach space of the modulus of convexity of power type q ⩾ 2 or Y is the L^q (Ω, Σ, μ) (1<q<+∞) space or Y is a Hilbert space. Furthermore, the stability of approximate isometries for the case that φ (x, y)=‖ x ‖ ^p + ‖ y^p or φ(x, y)=‖ x − y ‖ ^p for p≠1 is investigated.