Facile Formation of a Solid Electrolyte Interface as a Smart Blocking Layer for High‐Stability Sulfur Cathode

The practical application of lithium–sulfur batteries (LSBs) is hindered by their poor cycle life, which stems mainly from the “redox shuttle reactions” of dissolved polysulfides. To develop a high‐performance cathode for LSBs, encapsulation of polysulfides with a blocking layer is potentially straightforward. Herein, a novel strategy is reported encapsulate sulfur and the electrolyte together in porous carbon spheres by using a solid electrolyte interface (SEI) that can selectively sieve Li⁺ ions while efficiently avoiding polysulfide accumulation and suppressing undesired polysulfide migration. This strategy is simple, straightforward, and effective. The carbon/sulfur cathode only needs to be cycled a few times within a voltage window of 0.3–1.0 V to form such a smart SEI, allowing the resulting cathode to exhibit superior stability extending 600 cycles. This strategy can be combined with other existing advanced sulfur cathode designs to improve the overall performance of LSBs.     

改良型透水铺装对弱透水土质地区SS的去除效果试验

为研究适用于弱透水土质的改良型透水铺装对典型雨水径流污染物悬浮固体(SS)的去除效果,以嘉兴地区的淤泥质黏土为土基层制作试验装置,以人工模拟降雨的方法模拟并检测不同降雨重现期条件下改良型透水铺装装置削减径流污染物SS的效果,并以常规透水铺装和普通路面作为对比。结果表明:较小的降雨重现期更有利于透水铺装对SS的去除;弱透水土质条件下改良型透水铺装在对SS的去除过程中,不但去除率高于常规透水铺装,去除速率也得到了提高;在降雨重现期1 a条件下,改良型透水铺装平均每分钟比常规透水铺装多去除29.82%的SS。     

改良型透水铺装对弱透水土质地区的水质控制试验

为改善透水铺装在弱透水土质地区的应用,通过增加渗透导管的方式改良了常规透水铺装的土基层。通过人工降雨试验对改良型透水铺装及其不同结构层对弱透水土质地区典型雨水径流中COD、TN、TP和Cu~(2+)等污染物的去除效果进行了分析,并与相同条件下的常规透水铺装进行了对比。结果表明,改良型透水铺装对4种污染物的去除效果有明显增强,在60 min降雨历时条件下,降雨重现期为2 a时改良型透水铺装对4种污染物的去除能力分别提升了11.87%、27.61%、9.17%和29.02%,且降雨重现期越短越有利于透水铺装对COD、TN、TP和Cu~(2+)的去除。     

Oxidation behavior of fine-grained SiC-B4C/C composites up to 1400 °C

Fine-grained B₄C-SiC/C composites were fabricated using a ball-milling dispersion process. The oxidation behaviors of both fine-grained B₄C-SiC/C composites and coarse-grained B₄C-SiC/C composites at temperatures of up to 1400 °C were analyzed by the differential thermal analysis technique, and the surface morphology of the composites after isothermal oxidation at 800, 1200 and 1400 °C was examined by scanning electron microscopy (SEM). The results indicated that fine-grained B₄C-SiC/C composites had excellent oxidation resistance with self-healing properties at 1400 °C. A general model and mechanism for self-protection against oxidation of carbon materials were proposed.     

等离子体质谱法（ICP／MS）测量天然锇同位素丰度

本文报道ICP／MS测量天然锇同位素的测量方法。作中研究了样品浓度、积分时间、测量次数等对锇同位素丰度测量精度和准确度的影响，测得的同位素丰度与天然丰度一致。测量了锇的记忆效应。     

空间四杆机构步行机设计与仿真

将一种空间闭链RSTR机构应用到步行机设计中,通过对该机构进行运动分析,借助Pro/E仿真,得出步行机的足端运动轨迹曲线,并与现有的一种平面曲柄摇块步行机器人运动轨迹曲线进行了比较。结果表明,RSTR步行机在行走过程中,重心较平稳,速度也较均匀。由于RSTR步行机采用的是单自由度闭链机构,因此,它比多自由度空间开链机构的步行机控制简单。     

A 220 GHz dynamic frequency divider in 0.5 μm InP DHBT technology

A high performance 3 inch 0.5 μ m InP DHBT technology with three interconnecting layers has been developed. The epitaxial layer structure and geometry parameters of the device were carefully studied to get the required performances. The 0.5×5 μm² InP DHBTs demonstrated f_t=350 GHz, f_max=532 GHz and BV_CEO=4.8 V, which were modeled using Agilent-HBT large signal model. As a benchmark circuit, a dynamic frequency divider operating from 110 to 220 GHz has been designed, fabricated and measured with this technology. The ultra-high-speed 0.5 μm InP DHBT technology offers a combination of ultra-high-speed and high breakdown voltage, which makes it an ideal candidate for next generation 100 GHz+mixed signal integrated circuits.     

钢框架预应力节点的介绍与分析

介绍了一种新的钢框架节点——预应力钢结构节点，该节点在顶底角钢连接的节点中增设了钢拉杆。钢拉杆与梁平行，并通过张拉钢拉杆使梁柱间产生预压力。试验研究表明：在往复荷载下，该节点的耗能由顶底角钢的非弹性变形提供，而钢拉杆和梁柱均保持弹性。该节点的主要优点是（1）拥有自定心（self—centering）的能力从而大大减小了在地震后的残余变形；（2）初始刚度较大与全焊接节点相似：（3）地震下破坏集中在节点的角钢处，地震后可以较方便地通过更换节点处的角钢来修复节点。     

复合材料瓦面推力轴承设计与制造

为适应蓄能机组工况,选择合适的复合材料作为轴承瓦面材料。针对对复合材料瓦面推力轴承进行流体动力润滑计算,设计复合材料瓦面推力轴承,制造成复合材料瓦面推力轴承。研究成果表明可以应用于蓄能机组上。     

Application of spherical tuned liquid damper in vibration control of wind turbine due to earthquake excitations

A spherical tuned liquid damper (TLD) is proposed as a cost‐effective method to reduce the earthquake‐induced vibration of wind turbines. A 1/20‐scale test model was designed to investigate its performance of controlling the structural vibration. A series of free and forced vibration experiments with different water depths in hemispherical containers were performed on the shaking table. Three measured ground acceleration‐time histories, including El Centro NS, El Centro EW and Tianjin EW, were selected to verify the effectiveness of spherical TLD in suppressing the earthquake‐induced vibration. The experimental results showed that the spherical TLD could effectively improve the damping capacity of the test model. The standard deviation of the dynamic response could be effectively reduced when the excitation frequency was approximately equal to its fundamental frequency. The liquid sloshing motion in containers was characterized by a highly nonlinear and complex nature. The effectiveness of spherical TLDs does not increase linearly as the mass of water in containers and is influenced greatly by the frequency components of earthquake excitations. For El Centro EW excitation, the standard deviations of the dynamic responses could be reduced more than 40% when the liquid mass was about 2% of the generalized mass. Copyright © 2015 John Wiley & Sons, Ltd.