Spin-dependent Seebeck effect and huge growth of thermoelectric parameters at band edges in H- and F-doped graphene,free-standing and deposited on 4H-SiC(0001) C-face

Graphene halfly doped with H or F possesses local magnetization at the undoped C sites. Thus the Seebeck coefficient is different for each spin channel and its sign also changes depending on the spin polarization. Deposition of doped graphene on the C-face 4H-SiC(0001) with two buffer layers substantially varies the electronic and thermoelectric properties. These properties are efficiently calculated from the semiclassical Boltzmann equations, using the maximally-localized Wannier-functions interpolation of the band structures obtained with the density-functional theory. Our results indicate large growth of the thermopower and the ZT efficiency at the band edges. We show in the model discussion that this phenomenon is more general and applies also to other systems than graphene. It gives prospect for developing new spintronic devices working in the band-edge regime.     

Microbubble Phenomenon in the Grease Lubricating Film Induced by Micro-Oscillation

A microbubble phenomenon induced by micro-oscillation in the grease lubricating film confined within a nanogap between a highly polished steel ball and a smooth glass disc has been observed with an interferometer. Experimental results show that when the micro-oscillation frequency is a constant value, the microbubble number increases with the micro-oscillation amplitude. When the micro-oscillation amplitude is a constant value, the microbubble number increases with the micro-oscillation frequency when the latter is lower than the critical value and decreases with the micro-oscillation frequency when it is higher than the critical value. Theoretical models and analyses have been used to discuss the bubble formation and describe the characteristics of bubble movement.     

Electrochemical stability of lithium bis(oxatlato) borate containing solid polymer electrolyte for lithium ion batteries

The electrochemical stability of lithium bis(oxatlato) borate (LiBOB) containing solid polymer electrolyte has been evaluated both by inert electrode and real cathodes. Enhanced intrinsic anodic stability and decreased interface impedance, are obtained by addition of nano-sized MgO to PEO₂₀-LiBOB. It is also found that the LiBOB-containing SPEs exhibit prominent kinetic stability between 3.0 and 4.5 V. For cells using SPEs as the separators, good cycling performance is obtained for real 4 V class cathodes material LiNi_1/3Co_1/3Mn_1/3O₂ and LiCoO₂. The Li|PEO₂₀-LiBOB|LiNi_1/3Co_1/3Mn_1/3O₂ cell takes an initial capacity of 156.8 mAh g⁻¹, with retention of 142.5 mAh g⁻¹ after 20 cycles at 0.2C-rate. The cell also works well up to 1C-rate. The addition of nano-sized MgO into PEO₂₀-LiBOB readily reduces the irreversible capacity per cycle, both for LiNi_1/3Co_1/3Mn_1/3O₂ and LiCoO₂ cathodes. In addition, the critical role of LiBOB in obtaining kinetic stability and passivating ability towards cathodes are specially discussed.     

印度TATA步进梁式加热炉步进机械的设计与开发

介绍了印度TATA钢铁公司新建步进梁式加热炉步进机械的性能参数、设备结构及组成、相关设计及计算,设备运行平稳,实用可靠.     

PTA中颗粒污染物的测定

讨论了判断PTA是否受到颗粒污染物的污染及污染程度的方法。用氢氧化铵溶液溶解样品,测定样品的滤膜(0.2μm)和空滤膜的L值,可以判断PTA是否污染及污染程度。     

Economic evaluation of coalbed methane production in China

Roaring natural gas demand, energy security and environment protection concerns coupled with stringent emission reduction requirement have made China's abundant coalbed methane (CBM) resource an increasingly valuable energy source. However, not all of China's CBM resource is economic to develop under current technological condition and economic situation. In order to locate the CBM resource with economic viability to develop in China, economic evaluation of CBM production is conducted by applying net present value (NPV) method. The results indicate that more than half of CBM resource in China is economic to develop. It shows that CBM price, production rate and operating costs are the three major factors with most impact on the economic viability of the CBM development in target areas in China. The result also demonstrates that the economic limit production is roughly 1200 cubic meters per day. These economic evaluation results provide important information for both CBM companies and China government.     

接续盒异端接续冗余光纤的收容方法

介绍了使用接续盒对光缆异端进出接续时冗余光纤的收容方法，该收容方法克服了传统冗余光纤收容及拆纤维护不方便的缺点，为冗余光纤收容方法的规范化提供了技术基础。     

模拟深井条件下的PDC钻头破岩试验研究

利用深井破岩试验装置模拟不同井深（0～5km）压力条件下对泥岩进行了PDC钻头破岩试验，试验结果表明：随着井深（围压）的增加，岩石强度增加，破碎岩石的切削力增加，同时，PDC钻头齿形和结构对破岩效率影响较大，因此必须按深井条件和岩石特点进行PDC钻头齿形和结构设计，以达到提高机械钻速的目的。     

绳索救助中滑轮运用的力学分析

滑轮是绳索救助中一种典型、常用的辅助器材,其主要作用有改变作用力方向、省力、改变绳索运行轨迹和运输被困者等,正确合理地运用滑轮是绳索救助行动高效运行的关键环节之一。滑轮的本质是一种特殊的杠杆,对这一本质的正确理解,有助于救援人员更加科学合理地运用滑轮。     

北京小汤山地下水除氟示范工程的设计与运行

北京小汤山地下水除氟示范工程设计规模为1 000 m3/d,采用改性活性氧化铝作为除氟吸附剂,并采用三级串联式吸附工艺。运行结果表明,进水氟浓度约3 mg/L,出水水质达到国标要求,除氟运行费用为0.595元/m3。