烷基磺酸蒽醌电解质的合成及其在液流电池中的应用

分别以1,2-二羟基蒽醌、2,6-二羟基蒽醌和1,4-二羟基蒽为原料与丙烷磺内酯反应,合成了3种烷基磺酸基蒽醌[1-羟基-2-氧丙烷磺酸基蒽醌(1,2-AQPSH2)、2,6-二氧丙烷磺酸基蒽醌(2,6-AQDPSH2)和1-羟基-2-氧丙烷磺酸基蒽醌(1,4-AQPSH2)].研究了3种烷基磺酸基蒽醌在1 mol/L...     

基于摆度规律与CAD相结合的导瓦间隙分配算法研究及应用

导瓦间隙分配是水轮发电机组安装检修过程中一项十分重要的工作,合适的瓦间隙是机组健康运行的重要保障.针对瓦间隙计算存在的操作难度大、计算速度慢、精准度低等问题,建立了立式水轮发电机组盘车摆度模型,分析了其摆度特性,推导了实际最大净全摆度计算公式.通过分析瓦间隙计算公式的几何意义,提出了一种结合AutoCAD快速标注的瓦间...     

六自由度工业机器人手腕分析与优化综合

本文分析了用于六自由度工业机器人的球型手腕, 这种手腕具有结构紧凑, 姿态范围大, 定位精度高等特点.在运动学分析的基础上, 研究了手腕定位精度与各关节参数精度误差之间的关系, 给出了完整的误差数学模型, 借助于此模型通过优化设计, 得到了各关节参数精度的合理分配, 为机器人机械结构及控制系统的精度设计提供了依据.文章阐述了使机器人实现快速响应, 提高定位精度的优化设计方法.     

Atomically Thin Defect‐Rich Fe–Mn–O Hybrid Nanosheets as High Efficient Electrocatalyst for Water Oxidation

Engineering non‐noble metal–based electrocatalysts with superior water oxidation performance is highly desirable for the production of renewable chemical fuels. Here, an atomically thin low‐crystallinity Fe–Mn–O hybrid nanosheet grown on carbon cloth (Fe–Mn–O NS/CC) is successfully synthetized as an efficient oxygen evolution reaction (OER) catalyst. The synthesis strategy involves a facile reflux reaction and subsequent low‐temperature calcination process, and the morphology and composition of hybrid nanosheets can be tailored conveniently. The defect‐rich Fe–Mn–O ultrathin nanosheet with uniform element distribution enables exposure of more catalytic active sites; moreover, the atomic‐scale synergistic action of Mn and Fe oxide contributes to an enhanced intrinsic catalytic activity. Therefore, the optimized Fe–Mn–O hybrid nanosheets, with lateral sizes of about 100–600 nm and ≈1.4 nm in thickness, enable a low onset potential of 1.46 V, low overpotential of 273 mV for current density of 10 mA cm^?2, a small Tafel slope of 63.9 mV dec^?1, and superior durability, which are superior to that of individual MnO₂ and FeOOH electrode, and even outperforming most reported MnO₂‐based electrocatalysts.     

氧化锅生产锑白过程中去除油状氧化渣研究及应用

介绍了恒邦股份公司采用火法锑氧化锅氧化吹炼生产锑白产品,氧化锅生产过程中,因氧化锅熔液表面容易产生一种黑油状氧化渣,俗称“黑油”,覆盖在熔液表面,因没有较为实用的方法用于黑油的除去,不仅增加了员工劳动强度,而且因去除不及时,严重影响了氧化锅吹炼表面积,影响了氧化锅生产效率及锑白产品质量;针对此问题,通过实验研究,最终提出采用试剂硼砂能及时有效的对氧化锅表面黑油渣进行粘附去除,该方法存在操作简单、粘附黑油渣能力强、效率高、没有二次污染等有点,具有较高的应用推广价值。     

Cytotoxicity of murine B lymphocytes induced by human VH4-34 (VH4.21) gene-encoded monoclonal antibodies

We previously found that a ventricular isovolumic pressure-time curve could be well fitted by the difference between two S-shaped logistic curves for the pressure rising and falling components, and called it "hybrid logistic" function: P(t)=A/[1+exp[-(4B/A)(t-C)]]-D/[1+exp[-(4E/D)(t-F)]]+G. We reported that the parameters of this hybrid logistic function are useful to characterize left ventricular contraction and relaxation comprehensively. In this study, we investigated how well this hybrid logistic function could fit the isometric twitch force-time curves of cross-circulated right ventricular papillary muscles of 7 dogs. This function precisely fitted the isometric force curves with correlation coefficients above 0.9996, much better than another fitting function (F(t)=C(t/A)(B)exp[1-(t/A)(B)]) proposed by Nwasokwa. The present results indicate that our hybrid logistic function can also reasonably express the canine right ventricular papillary muscle isometric twitch force-time curve. We suggest the possibility that the parameters of this hybrid logistic function are also useful to comprehensively characterize right ventricular papillary muscle twitch contraction and relaxation.     

Network-aware Virtual Machine Migration Based on Gene Aggregation Genetic Algorithm

Mobile Networks and Applications - As a key technology of cloud computing, virtualization technology enables multiple virtual machines (VMs) to run on a host to meet the operational needs and...     

Positive Effect of Ge Vacancies on Facilitating Band Convergence and Suppressing Bipolar Transport in GeTe‐Based Alloys for High Thermoelectric Performance

Because the intrinsic Ge vacancies in GeTe usually lead to high hole concentration beyond the optimal range, many previous studies tend to consider Ge vacancies as negative effects on increasing the figure of merit ZT of GeTe‐based alloys, and consequently have proposed various approaches to suppress Ge vacancies. However, in this work, it is demonstrated that the Ge vacancies can have great positive effects on enhancing the ZT of GeTe‐based alloys when the hole concentration falls into the optimal range. First, hole concentration of GeTe is reduced close to the optimal range by co‐alloying of Pb and Bi, and then the Ge vacancies are increased by adding excess Te into the Ge_0.8Pb_0.1Bi_0.1Te_1+x. The Ge vacancies can cause lattice shrinkage and promote rhombohedral‐to‐cubic phase transition. As revealed by first‐principle calculations, theoretical simulations, and experimental tests, Ge vacancies can facilitate the band convergence, suppress the bipolar transport at higher temperature range, and reduce the lattice thermal conductivity. Combining these effects, a peak ZT of 1.92 at 637 K and an average ZT of 1.34 within 300–773 K in Ge_0.8Pb_0.1Bi_0.1Te_1.06 can be obtained, demonstrating the great significance of utilizing vacancy‐type defects for enhancing ZT.     

All‐Natural,Degradable, Rolled‐Up Straws Based on Cellulose Micro‐ and Nano‐Hybrid Fibers

Among all the plastic pollution, straws have brought particularly intricate problems since they are single use, consumed in a large volume, cannot be recycled in most places, and can never be fully degraded. To solve this problem, replacements for plastic straws are being developed following with the global trend of plastic straw bans. Nevertheless, none of the available degradable alternatives are satisfactory due to drawbacks including poor natural degradability, high cost, low mechanical performance, and poor water stability. Here, all‐natural degradable straws are designed by hybridizing cellulose nanofibers and microfibers in a binder‐free manner. Straws are fabricated by rolling up the wet hybrid film and sealed by the internal hydrogen bonding formed among the cellulose fibers after drying. The cellulose hybrid straws show exceptional behaviors including 1) excellent mechanical performance (high tensile strength of ≈70 MPa and high ductility with a fracture strain of 12.7%), 2) sufficient hydrostability (10× wet mechanical strength compared to commercial paper straw), 3) low cost, and 4) high natural degradability. Given the low‐cost raw materials, the binder‐free hybrid design based on cellulose structure can potentially be a suitable solution to solve the environmental challenges brought by the enormous usage of plastics straws.