[en] Constitutional liquation means the local eutectic melting of second-phase particles in a matrix at temperatures above the eutectic temperature and below the solidus of the alloy, which may occur in the heat-affected zone (HAZ) during welding. In the present paper, the constitutional liquation in the Al-Cu system was computationally investigated using the DICTRA program coupled with critically assessed thermodynamic and kinetic databases. Computer simulated results are in quantitative agreement with existing experimental data. The computational procedures for obtaining the critical heating rate to avoid constitutional liquation are demonstrated. The critical heating rate was found to be inversely proportional to the square of the precipitate size. The present computational procedures can be readily extended to predict the susceptibility of multicomponent commercial alloys to constitutional liquation during welding with available thermodynamic and kinetic databases

[en] Ordering and self-organization are critical in determining the dynamics of reaction-diffusion systems. Here we show a unique pattern formation mechanism, dictated by the coupling of thermodynamic instability and kinetic anisotropy. Intrinsically different from the physical origin of Turing instability and patterning, the ordered patterns we obtained are caused by the interplay of the instability from uphill diffusion, the symmetry breaking from anisotropic diffusion, and the reactions. To understand the formation of the void/gas bubble superlattices in crystals under irradiation, we establish a general theoretical framework to predict the symmetry selection of superlattice structures associated with anisotropic diffusion. Through analytical study and phase field simulations, we found that the symmetry of a superlattice is determined by the coupling of diffusion anisotropy and the reaction rate, which indicates a new type of bifurcation phenomenon. Our discovery suggests a means for designing target experiments to tailor different microstructural patterns.

[en] This is the modified version of The Preliminary Design on the Hardware and Nets of HL-2A Tokamak. In this version, centralized control as well as the field bus communication on HL-2A Tokamak is used. The hardware components and the operational theory are introduced. The questions of practice program, extensibility, centralized control, cooperation with other subsystems and the continuous adaptation of present device are all discussed. The budget of the system is detailed. To keep the step with the overall engineering constructions of HL-2A, suggestions of the time program are presented for the system design, instrument purchases, installation, construction, user program development and the final operation processes for the machine control system of HL-2A Tokamak

[en] Making use of the MATLAB language to analyze the stability of the plasma current and radial position control system in the HL-2A, the PID controller is designed and the system response is simulated. (authors)

[en] The design principle and basic structure of the central control system for HL-2A Tokamak are introduced. Having been limited by manpower and money, the central control system should not be too expensive and too advanced. On the other hand, because of the complexity of the machine and the difficulty the author will encounter when operating the machine, the central control system should be advanced enough. If use the same technology for HL-1M to control HL-2A, the author would fail to fulfill authors' experiment goal. The central control system consists of software and hardware. The software mainly includes: (a) system monitor and control software; (b) discharge monitor and control software; (c) network and communication software. Hardware includes: (a) PLC for machine control, personnel protection and machine protection; and (b) VME computer, for the feedback control of the discharge

[en] HL-2A Discharge Control System consists of one or more VXI work stations so as to compose an all digital control system. The DCS are used to measure and control the poloidal coils, the main tasks of the poloidal coils are exploding, keeping and controlling the current of plasma. These coils explode plasma and keep it in the determined position

No abstract available

[en] Shaft is an important part of equipment, it connects rotary assembly and immobile assembly. Its reliability is important for equipment. When shaft circumrotates rapidly in equipment, its surface is easy abrasion. Abrasion is an important factor to conduce machine comedown function. So equipment demands shaft must enough reliability. Radial load is primary factor to conduce shaft occur bad abrasion. Because the configuration of shaft is especial, abrasion is slow, it is difficult to estimate the life of shaft. Accelerated life for radial load to shaft can estimate reliability of shaft in shortly time. Research disabled mechanism, insure disabled mechanism unable change. On this basis, constitute project for accelerated life to test. Anti power is the accelerated model. This test processes in tester of abrasion. There are four stree levels. Through nearly 2 years test, there were 3 shafts failure in the highest stress level, no failure in other 3 stress levels. Calculate the reliability, the result indicates the shaft satisfies the demand of collectivity. (authors)

[en] Using BWR (Benedict-Webb-Rubin) formula, authors have studied the relationships between the required inner pressure at 500 K, 400 K, 300 K, 77 K, 35 K, respectively, in the micro balloon's diameter of 100 μm, 200 μm, 400 μm, 520 μm, respectively, and the thickness of liquid layer in the target at 22 K. The authors found that the fuel pressure at low temperature is much more lower than that at room temperature. (authors)

[en] In order to analyze the far-field temperature gradient, a finite element analysis (FEA) of the heat transfer in hollow micro-sphere filled with ICF fuel was made, providing the border adiabatic, meshing the model intellectualizedly, and supposing the parameter as 3, the cell as triangle. When the work temperature of the target was 24 K, in order to maintain the balance of the gas bubble in the micro-sphere, the temperature gradient in the target was 14.02 K/cm. The digital simulation result showed that the external temperature gradient was 7.75 K/cm. The result fits well with the data achieved by experiment. This shows the mathematics model is credible, and can be applied in the manufacture of the cryogenic target. (authors)