脉冲电流对6016-T4铝合金板材力学性能的影响

为研究在电流辅助成形时脉冲电流的电流密度、占空比和脉冲频率3个因素对6016-T4铝合金板材力学性能的影响规律,设计了3因素5水平的正交实验。实验表明,对6016-T4铝合金力学性能影响的主次因素是:电流密度>占空比>脉冲频率。在此基础上,选用主次2个因素,即电流密度和脉冲频率,使用控制变量法进行进一步的实验研究。实验结果表明,电流密度对6016-T4铝合金力学性能影响较大,改变电流密度的同时带来了明显的焦耳热效应,该效应对材料有明显的软化作用,降低了材料的流动应力,但是,同时也降低了铝合金板的伸长率,这是因为过大的电流密度加剧了试样的主应变演化,进而促进了试样的断裂。而脉冲频率的变化对6016-T4铝合金板材的力学性能影响很小,这也印证了正交实验的结论。     

FeOOH–CoS composite catalyst with high catalytic performances for oxygen evolution reaction at high current density

Water electrolysis is an efficient approach for high-purity hydrogen production. However, the anodic sluggish oxygen evolution reaction (OER) always needs high overpotential and thus brings about superfluous electricity cost of water electrolysis. Therefore, exploiting highly efficient OER electrocatalysts with small overpotential especially at high current density will undoubtedly boost the development of industrial water electrolysis. Herein, we used a simple hydrothermal method to prepare a novel FeOOH–CoS nanocomposite on nickel foam (NF). The as-prepared FeOOH–CoS/NF catalyst displays an excellent OER performance with extremely low overpotentials of 306 and 329 mV at 500 and 1000 mA cm⁻² in 1.0 M KOH, respectively. In addition, the FeOOH–CoS/NF catalyst can maintain excellent catalytic stability for more than 50 h, and the OER catalytic activity shows almost no attenuation no matter after 1000 repeated CV cycles or 50 h of stability test. The high catalytic activity and stability have exceeded most non-noble metal electrocatalysts reported in literature, which makes the FeOOH–CoS/NF composite catalyst have promising applications in the industrial water electrolysis.     

ZnO基薄膜晶体管的研究

ZnO是一种宽带隙的光电半导体材料,能应用于很多领域,如可用在压敏变阻器、声表面波器件、气敏元件、紫外光探测等。ZnO也可以作为有源层应用于薄膜晶体管(TFT)中。ZnO基薄膜晶体管具有以下突出优势:对于可见光部分平均具有80%以上的透射率,迁移率可以高达36cm2/V·s,开/关电流比大于106,可在较低温度(甚至室温)下制备。基于这些优点,ZnOTFT具有取代有源矩阵液晶显示器中常规a-SiTFT的趋势。同时对ZnOTFT的研究也推动了透明电子学的发展。本文阐述了ZnOTFT优越的电学性能,指出了其目前尚存在的不足,并对其发展前景进行了展望。     

DISPERSION COMPENSATION CFBG IN100km 10Gbit／s RECIRCULATING SYSTEMS

A 10Gbit/s recirculating system is configured with Chirped Fiber Bragg Grating (CFBG) for the dispersion compensation. For the first time, the transmission distance in the loop reaches 1000km with bit error rate of 10-9. The effect of the group delay ripple of the fiber grating is also investigated in the recirculating systems, and it is shown that the transmission distance is limited to 4 cycles (4×167.1km ) in the loop with the power penalty fluctuation below 1.0dB. Thus the group delay ripple should be reduced to allow for the wavelength drift of±5GHz. At the end of this letter, the principles are given for designing long haul recirculating systems with dispersion compensation CFBG.     

含氮金刚石结构中Jahn-Teller畸变效应的计算

研究了由J.Bourgoin和M.Lannoo提出的半导体内Jahn-Teller畸变效应的计算理论。应用Bourgoin和Lannoo的方法研究了含中心氮杂质金刚石结构的Jahn-Teller畸变问题,计算了34C+N簇团的T2模耦合沿%111&晶向的Jahn-Teller畸变效应,结果与实验相符。     

高输出阻抗多功能电流模式双二阶滤波器

提出了一种基于多输出端差动差分电流传送器的多功能电流模式滤波器电路结构。该电路用三个多输出端差动差分电流传送器，五个或四个接地电阻和两个接地电容，同时实现了反相和，或同相带通和低通或带通和高通滤波响应特性。分析并模拟了所提出的滤波器的传递特性，PSPICE仿真结果表明，所提出的电路方案正确有效。电路具有灵敏度低，输出阻抗高，滤波器固有频率ωo和品质因数Q相互独立可调，多功能的优点，适于实现全集成连续时间滤波器。     

Effect of Strain Rate on Discontinuous Flow and Mechanical Characteristics of High-Nitrogenous Steel

Experimental study on the effect of strain rate on discontinuous flow and mechanical characteristics of the high-nitrogenous steel Kh23AG19F has been performed. Within the range of strain rates from 4.62 · 10^-5 to 1.85 · 10 ^-4 s^-1, discontinuous flow, reflected by serration on the tensile diagram, is chiefly determined by intergranular deformation mechanisms. Under strain rates over 1.85 · 10^-2 s^-1, combined deformation modes prevail, which cause a change in the character of discontinuous flow and transform a serrated tensile diagram into a wavy graph, with the yield stress of steel increased significantly.     

胡状集北部沙一下段盐岩沉积与油气分布规律研究

运用层序地层学的方法,利用地震岩性反演手段,对东濮凹陷胡状集北部沙一下段盐岩透镜体形成古环境、盐湖层序结构模式以及盐岩透镜体所在区域油气分布规律进行了研究.结果认为：岩性透镜体是湖泊中心或斜坡带底部发育的盐类扇体,其盐间薄层白云岩、泥质白云岩和砂岩为有利的勘探目标;对研究区寻找隐蔽油气圈闭具有重要的指导意义.     

开关电源的平均电流自动均流技术

针对多个开关电源并联时易出现负载电流在各模块间分配不均的现象,介绍了常用的负载电流自动均流法——平均电流自动均流法及其工作特性。并针对其存在母线电压降低的缺陷,提出了一种改进的平均电流自动均流方法,经试验证明均流精度比较高。     

MPTA型原油脱金属剂的工业应用

在对高金属含量原油进行初步评价的基础上，利用SH—Ⅰ型电脱盐试验仪对自主开发的MPTA型原油脱金属剂进行了原油脱金属的实验室研究。结果表明，当MPTA型脱金属剂加入量为250μg／g时，钙的脱除率可达97．4％，并且对其它金属元素，如镍、铁、钠、锰、铝和钒也有明显的脱除效果。该剂在山东恒源石油化工股份有限公司重交沥青车间500kt／a的电脱盐装置上进行原油脱金属工业试验的结果表明，经过二级电脱盐处理后，钙的脱除率达到99．1％，钠的脱除率为94．6％，铁的脱除率为82．9％，并可在一定程度上降低原油中镍和铜的含量。使用MPTA型原油脱金属剂显著降低了一、二级电脱盐装置的电场电流，有利于炼油厂的节能降耗。