Advanced Materials Research Vols. 535-537

Abstract: The support of soft rock roadway is the worldwide problem in Coal resources exploitation, and this problem affect production safety and efficiency of coal mining serious. The surrounding rock of Ronghua coal mine is complex soft rock with expansibility, complex geological structure and deep high stress, large deformation of rocks, floor heave serious , supporting difficulties, frequent overhaul, waste a lot of manpower and material resources, and serious threats to the mine's safety production. After many years of practicing, a new idea of supporting the soft rock in different time periods, which is” avoiding first, then resistance”, was propounded. Based on the lithology of surrounding rock and geologic structure, the roadway’s length of service, application, and service condition were considered, several pointed support schemes of roadway in -650m level: Super-strong supporting, High-strong supporting, Flexibility combined supporting and Retractable U-shaped supporting were confirmed. A whole soft rock supporting technology system has been formed which effectively solved the difficult problems of soft rock supporting. These achievements can provide useful experience for similar engineering problems.

Abstract: According to the three kinds of MRT3-BA steel technological processes, which include BOF→LF→CC, BOF→RH→CC and BOF→LF→RH→CC, some systematic analysis are introduced to research on the contents of T[O] and [N], and the type, composition and quantity of micro-inclusions in the three processes. The level of cleanliness in billet will also be systematic analysed in comparative. The results of the study show that the contents of T[O] respectively are 20.8×10-6, 14.3×10-6 and 13×10-6 in billet of Process 1, Process 2, Process 3. Through the comparison with production data of other manufacturers, control of T[O] has reached a high level in MRT3-BA deep punching steel. The numbers of micro-inclusions respectively are 6.8/mm2, 5.66/mm2 and 5.36/mm2 in billet; the control level in MRT3-BA steel has reached domestic advanced level. Taken steel cleanliness and production cost into account, the better technological process of MRT3-BA stamping steel is BOF→RH→CC.

Abstract: The power spectrum method of frequency domain is presented in this paper for analyzing the four states of aluminum reduction cell (that is the normal condition, the liquid aluminum fluctuation, the abnormally low polar distance or drop of an anode and the anodic long bud), the characteristics of frequency domain under circumstances of function and malfunction and pointing out that groove resistance simulation analysis provide reliable basis for fault detection of aluminum reduction cell.

Abstract: Based on detailed analysis of the influencing factors on energy security, this paper build the China's energy security evaluation index system considering energy transport from the four aspects of energy supply, energy consumption, energy, transport, energy and social environment, then classified the level of energy security according to the evaluation system. At last, this paper made an empirical analysis on the 2001-2010 energy security through the Analytic Hierarchy Process.

Abstract: Single ion conducting polymer electrolytes synthesized through a copolymer poly(lithium 2-acrylamido-2-methylpropanesulfonic acid-co-vinyl triethoxysilane) and a crosslinker poly(etheylene glycol) dimethacrylate (PEGDMA) were prepared. Scanning electron microscope (SEM) was used to observe the morphology of the surface and cross-section of the polymer electrolyte membrane. AC impedance and linear sweep voltammetry were used to investigate the electrochemical properties of the polymer electrolytes. It was found that the obtained membrane had a typical amorphous structure and possessed a smooth surface. The bulk resistance of the polymer electrolyte increased with the increase in the plasticizer uptake. The electrochemical stability increased with the increase in the content of VTES.

Abstract: Superconducting magnetic energy storage system using superconducting coils to store energy in the form of electromagnetic energy, Superconducting magnetic energy storage not only can reactive power compensation but also can active thought the power of mediation. It can achieve the power of the four-quadrant operation. This article outlines the advantages of the superconducting energy storage technology and development status, superconducting energy storage and how various components used. Finally describes how the four-quadrant active and power exchange. I think 21st century technology superconducting will develop far-reaching impact semiconductors as the 20th century semiconductors. So it has a great significance.

Abstract: An electrolyte, N,N′-1-ethyl-4-butyl, triethylene diamine hexafluorophosphate dissolved in glutaronitrile, was developed and investigated in a symmetrical supercapacitor using activated carbon as electrodes (active carbon/active carbon). The electrochemical erformance of the supercapacitor was examined using ac impedance and constant current charging/discharging tests. According to the results, its singleanode specific capacitance could reach 324.7 Fg−1. The supercapacitor also has better capacitance characteristics.

Abstract: The RE-Mg-Ni-based A2B7-type La0.75−xPrxMg0.25Ni3.2Co0.2Al0.1 (x = 0, 0.1, 0.2, 0.3, 0.4) electrode alloys were synthesized by melt spinning technology. The impacts of the melt spinning and the substitution of Pr for La on the microstructures and electrochemical characteristics of the alloys were investigated in detail. The results reveal that the as-cast and spun alloys have a multiphase structure, containing two main phases (La, Mg)2Ni7 and LaNi5 as well as a residual phase LaNi2. The melt spinning results in a notable grain refinement of the alloys without altering the phase structure of the alloys. The discharge capacity of the (x=0.1) alloy first mounts up and then falls with rising the spinning rate. And the as-spun (10 m/s) alloy yields the maximum discharge capacity with the variation of Pr content. Furthermore, the measurements of the electrochemical hydrogen storage kinetics reveal that the high rate discharge ability (HRD), the hydrogen diffusion coefficient (D) and the limiting current density (IL) of the alloys first increases then decreases with rising the spinning rate and the amount of Pr substitution.

Abstract: This paper studied the impact of silicon oxide layer on photovoltaic characteristic of iron-doped amorphous carbon film/silicon heterojunction (a-C:Fe/Si). The results show that a native SiO2 layer on the silicon surface can provide a significant improvement of the a-C:Fe/Si devices’ photovoltaic performances, especially for the short circuit current and fill factor. This improvement partly may be attributed to the electron recombination process is suppressed and the interface is modified by the SiO2 film based on the open circuit voltage decay measurement.

Abstract: After reviewing the development of CdTe solar cells, the merits of superstrate and substrate configuration have been discussed. Then, the material process techniques are investigated according to their application, following with discuss at the challenges.