波浪结构超疏水表面对液滴聚并弹跳的影响

液滴自发聚并在自然和工业中广泛存在,如何高效去除聚并液滴是强化滴状冷凝换热、防结冰等的重要环节。采用数值模拟方法研究了不同半径比液滴在超疏水平壁面和超疏水波浪形壁面上的聚并起跳行为。研究发现,在平壁面上聚并的液滴水平速度与竖直速度差1～2个数量级,液滴的水平方向位移小,聚并后难以有效去除;在波浪形壁面上,由于液桥撞击在斜面上,产生较大的水平分力,聚并后其水平速度保持与竖直速度在同一数量级,水平位移显著增大;并且波浪结构对液滴弹跳过程影响显著,随波浪高宽比的增大液滴水平位移增大且弹跳高度减小,有效促进了液滴的水平运动,且当高宽比为0.21时,促进作用接近峰值。研究结果为聚并液滴的有效去除提供了新参考。     

某110kV线路开关跳跃原因分析

文中针对一次开关跳跃事故,具体分析了导致开关跳跃事故发生的原因,对二次回路提出了具体的改进方案,并对二次回路完善和规范现场工作行为提出了可行性的建议,提高了运行可靠性。     

Imaging applications of synchrotron X-ray phase-contrast microtomography in biological morphology and biomaterials science. I. General aspects of the technique and its advantages in the analysis of millimetre-sized arthropod structure

Synchrotron‐generated X‐rays provide scientists with a multitude of investigative techniques well suited for the analysis of the composition and structure of all types of materials and specimens. Here, we describe the properties of synchrotron‐generated X‐rays and the advantages that they provide for qualitative morphological research of millimetre‐sized biological organisms and biomaterials. Case studies of the anatomy of insect heads, of whole microarthropods and of the three‐dimensional reconstruction of the cuticular tendons of jumping beetles, all performed at the beamline ID19 of the European Synchrotron Radiation Facility (ESRF), are presented to illustrate the techniques of phase‐contrast tomography available for anatomical and structural investigations. Various sample preparation techniques are described and compared and experimental settings that we have found to be particularly successful are given. On comparing the strengths and weaknesses of the technique with traditional histological thin sectioning, we conclude that synchrotron radiation microtomography has a great potential in biological microanatomy.     

用KBE方法绘制车轮跳动包络面的实用软件

本文围绕KBE技术在车身设计中的应用，用C语言编制程序对车轮跳动及转动进行模拟，并采集、筛选存储数据，然后利用CATIA软件的IUA(Interactive User Access)功能，在C语言模块所形成数据基础上形成车轮跳动包络面，并对已有的零件进行校核。     

车辆发生跳跃现象的传动系自激振动研究

介绍国内外关于车辆跳跃现象的研究现状．并分析跳跃现象产生的机理。指出在滑转率大于临界滑转率时，地面附着系数具有随滑转率的增加而减少的特性，这是导致车辆动力传动系发生自激振动的原因．从而引起车辆发生跳跃现象，及有关抑制自激振动的措施。     

磷肥工业高氟废水的处理方法

介绍湿法磷酸高氟废水的处理方法.传统的废水处理工艺或因除氟效果差,或因成本高,不能满足高氟废水的处理要求.提出采用二级石灰乳过量-硫酸反滴法处理高氟废水的新工艺,控制第一级中和反应pH4-6,第二级中和反应pH9～11,通过硫酸调控pH至6～9,可达到氟离子质量浓度小于10mg/L的排放最高标准.此方法工艺简单,运行成本低.     

Similar admittance behavior of amorphous silicon carbide and nitride dielectrics within the MIS structure

PECVD grown a-SiNx:H and a-SiCx:H films were investigated as dielectric films in the form of metal/insulator/p-silicon (MIS) structures. AC admittance of MIS structures was measured as a function of dc gate bias voltages and frequencies (1-1000 kHz) of the superimposed ac bias voltage (10 mV). For each applied bias voltage (from accumulating to inverting bias regimes), temperature (T) dependence of both capacitance (C) and conductance (G/ω) were measured to investigate majority/minority carrier behavior under various frequencies ω (kHz-MHz) as parameters. C and G/ω-T-ω measurements reveal that observed pairs of capacitance steps and conductance peaks are related to traps lying on the same energy value, residing in the insulator and at the interface of insulator/semiconductor structure and differing only through capture cross-sections. On the other hand, surface band bending (ψ_s) of silicon and activation energy (E_A) deduced from the Arrhenius plot of the frequency vs. reciprocal temperature as a function of gate bias (V_G) seem linearly dependent, implying that E_A reflects the ψ_s variation.     

Premature deactivation of soleus during the propulsive phase of cat jumping

It has been shown that cat soleus (SOL) forces remain nearly constant despite increases in electromyography (EMG) activity for increasing speeds of locomotion, while medial gastrocnemius (MG) forces and EMG activity increase in parallel. Furthermore, during jumping, average cat SOL forces decrease, while average EMG activity increases dramatically compared with walking conditions. Finally, during rapid paw-shake movements, SOL forces and EMG activities are nearly zero. Based on these results, we hypothesized that the SOL is deactivated, despite ankle extensor requirements, if the contractile conditions limit SOL force potential severely. The purposes of this study were to (i) investigate SOL EMG activity and force as a function of its contractile conditions during jumping, (ii) test whether SOL EMG activity is associated with SOL contractile conditions, and (iii) determine the functional implications of SOL EMG activity during jumping. It was found that the SOL was prematurely deactivated in two distinct phases during the propulsive phase of jumping, in which shortening speeds approached or even exceeded the maximal speed of muscle shortening. We concluded that the SOL was prematurely deactivated to save energy because its mechanical work output approached zero, and speculated that the first phase of deactivation might be caused by a decrease in group Ia firing associated with active shortening and the second by a pre-programmed response inherent to the central pattern generator.     

基于遗传算法的加工中心工步排序优化方法

在加工中心加工复杂零件时，工步多，其顺序直接影响加工质量和生产效率。在分析工步排序原则和典型工艺路线的基础上，建立了一个加工中心工步排序优化模型；将遗传算法应用到工步排序优化中，对算法的应用机理进行了详细讨论，提出了一种启发式基因重组方法；并示例验证了工步排序优化方法。     

低温电流比较仪动态特性的研究

低温电流比较仪是现代电测量技术中最为准确的比例量具，在传递量子化霍尔电阻基准的量值时发挥了独特的作用。为了进一步提高CCC的比例准确度，一个有效的方法是采用匝数较多的绕组。但国际上各实验室均遇到了绕组匝数较高时电流会发生跳跃的困难，目前未见到对此问题进行分析及提出解决办法的文章。本文对CCC系统的动态特性进行了分析，找到了产生该现象的原因，并采取措施改进了系统的动态特性，避免了跳跃现象。与国际上的同类装置相比，CCC的绕组匝数被提高了8倍，信噪比及比例准确度也有了很大的提高。结合其他措施，完成了综合不确定度为10^-10量级的量子化霍尔电阻标准装置。