出口加强杆结构与布置方式对风机性能影响的试验研究

为保证风机出口蜗板面的平整,往往在风机出口采用加强杆进行固定。改变出口加强杆的高度与位置对风机性能会产生一定的影响。本文通过试验的方法对加强杆的高度与风机实际出口高度之间的最佳比值范围区间展开分析,给出了改善性能的合理匹配区间。     

炉压控制在铸件热处理中的应用

通过对炉压控制技术的分析,介绍了炉压控制在热处理炉的应用,详细论述了炉压控制在实际应用中所面临的问题及其解决方法。     

医用内窥镜系统体内驱动方式的研究

提出了一种新型的医用内窥镜系统的体内驱动方式和相应的驱动机构。此方式利用螺旋旋转时产生的牵引力推动医用内窥镜系统在人体内腔中运行，同时利用螺旋旋转时产生的动压效应建立起动压润滑粘液膜，使医用内窥镜系统在体内运行时不与内腔壁发生直接接触。避免对人体有机组织产生损伤。详细分析计算了用此方法驱动的医用内窥镜系统在不同半径、不同粘度粘液和不同弹性模量的内腔中的轴向运行速度和形成的粘液膜厚度，结果表明，用此方法驱动的医用内窥镜系统在人体内腔中运行时可以形成足够厚的粘液膜把医用内窥镜系统与内腔壁隔开，实现以较快速度的悬浮运行。上述分析结果已被实验研究所证实。     

The Inclusion of the Geometrical Shape of the Cutter into the Optimisation of the Milling Process

The paper deals with the optimisation model of cutting variables by which the manufacturing costs should be reduced to the lowest possible value. The optimisation strategy takes place in two steps by taking into account all input variables (technological limitations). First, the tool geometric variables are changed using selected cutting variables; in this way, the smallest cutting force variables are determined. Geometric variables for the case of the smallest cutting force are used for the second optimisation step in which the cutting variables are changed. Optimisation of the cutting variables is tested practically under workshop conditions. In this way, important information about the validity of the optimised values is obtained. If there are significant differences between the theoretical and practical values, then the theoretical values must be corrected (correction of cutting variables). As the study of the cutting processes requires much experimental and theoretical work and applies to a very large body of data, we have organised an information centre for cutting conditions. When forming the information centre for cutting conditions, it was impossible to avoid the requirement that the technological database must be actively included in the computer-supported integrated manufacture.     

花键轴齿形成形中齿根开裂的研究

应用有限元分析软件,对花键轴的齿形成形过程进行模拟.通过研究应力分布,证实齿根开裂现象的发生,找到齿根开裂的原因.通过分析断裂因子的分布和变化,预测可能发生开裂的位置.结合六齿矩形花键轴实际成形情况进行模拟计算,获得了入模半锥角的较佳取值范围.     

对JT-6-19推焦车推焦杆震动的探讨

JT-6-19推焦车在推焦杆推焦进退过程中,出现不同程度的震动.分析推焦杆推焦中的各种因素及受力情况,找出主要因素,减小水平度公差,减小震动.     

An algorithm for the estimation of the quality of the spot welds

Spot welds are widely used in industry, especially in automotive, so welds must be reliable. One of the approaches to estimate the quality of spot welds is to use ultrasonic testing. Spot welding is used in the automotive repair industry as well. However, a spot weld testing device, dedicated for the automotive repair industry, is not available. The objective of this work was to develop an algorithm for estimation of the quality of spot welds, to be used in a simple device in the automotive repair industry. The algorithm developed identifies the peaks in the acquired signal and separates the main peaks (ultrasonic signal reflected from the backwall of the weld) from intermediate peaks (which identify the defects in the weld or undersized weld). Then, according to the peak distribution and peak amplitude variations in the signal, the quality of the weld is determined and an automatic pass or fail indication given. The algorithm was verified using a finite element model of a good weld, an undersized weld and a weld with a pore.     

Application of the electroluminescence phenomenon to the examination of the area of real contact

An experiment that uses the electroluminescence phenomenon to determine the area of real contact (ARC) between metal and phosphor is described. An electroluminescent cell was constructed in which one of the electrodes is a metal sample of a given roughness. The influence of the roughness of the sample on the intensity of luminosity of the electroluminescent cell was examined. It is found that the changes in the intensity of luminosity are related to the changes in the ARC.     

冷却塔风筒内流速场分布的研究

在分析冷却塔构成的基础上，建立了描述冷却冷却塔风筒内流场分布的数学模型，进而利用MATLAB语言求出了偏微分方程组的数值解，绘出了风筒内的流场。经研究发现，在风筒的中心处，存在一个空气倒吸的区域。最后，提出了消除空气倒吸现象的措施。     

轴流风机叶片断裂的原因分析及系统对风机性能影响的探讨

对某厂房轴流风机叶片断裂的原因进行了分析,探讨了系统对该风机的性能影响,从而制定了切实可行的措施,使该风机安全运行。     

新乡南站远程自动供水系统可靠性设计

针对51单片机应用系统中普遍存在的干扰现象,结合应用实践,对干扰的来源和解决方法进行了归纳和总结。     

吸附式干燥器前置过滤器重要性分析

从吸附式干燥器的设计原理,剖析压缩空气净化系统中用前置过滤器减少进入吸附式干燥器的水分和油分的重要性。     

从民营企业的现状谈民营企业的发展

我国的民营企业发展到今天这个地步,已是经过市场大浪的淘洗,存者能够经历风吹浪打,败者已随潮流而退,民营科技型企业则是一支生力军,成为推动科技进步和促进社会主义市场经济发展的一支重要力量。分析了民营企业的现状、企业家的现状、企业管理、企业文化等,为新介入衡器行业的民营企业的发展提供了一个参考的模式,以促进其整体素质的提升。     

Study of the influence of the friction clutch operability on the performance of the switch motor

In this paper, the results of studying the efficiency of an SP-6 M switch motor have been presented. The friction clutch plays an important role during the transmission of torque from a motor to an actuator. To study a motor switch, a test rig was developed in order to determine the necessary force to move switchblades depending on the pressing force of the friction clutch. The tribological properties of the friction disk materials have been investigated using a specially designed test machine.     

基于UG-NX4平台KBE技术在汽车覆盖件模具设计中应用

总结了传统汽车覆盖件模具设计的不足之处,提出将KBE技术应用于汽车覆盖件设计可以克服这些不足,并对基于UG-NX4这一技术的实现给出实例,旨在推动这一技术的应用,提高我国覆盖件模具设计的水平。     

Unravelling the structure of the lamellipodium

Summary Pushing at the cell front is the business of lamellipodia and understanding how lamellipodia function requires knowledge of their structural organization. Analysis of extracted, critical-point-dried cells by electron microscopy has led to a current dogma that the lamellipodium pushes as a branched array of actin filaments, with a branching angle of 70 degrees , defined by the Arp2/3 complex. Comparison of different preparative methods indicates that the critical-point-drying-replica technique introduces distortions into actin networks, such that crossing filaments may appear branched. After negative staining and from preliminary studies by cryo-electron tomography, no clear evidence could be found for actin filament branching in lamellipodia. From recent observations of a sub-class of actin speckles in lamellipodia that exhibit a dynamic behaviour similar to speckles in the lamella region behind, it has been proposed that the lamellipodium surfs on top of the lamella. Negative stain electron microscopy and cryo-electron microscopy of fixed cells, which reveal the entire complement of filaments in lamellipodia show, however, that there is no separate, second array of filaments beneath the lamellipodium network. From present data, we conclude that the lamellipodium is a distinct protrusive entity composed of a network of primarily unbranched actin filaments. Cryo-electron tomography of snap-frozen intact cells will be required to finally clarify the three-dimensional arrangement of actin filaments in lamellipodia in vivo.     

利用图书馆资源搭建高校素质教育平台

知识经济时代的到来,凸显了教育过程中培养全面发展的高素质人才的重要性,加强大学生素质教育,成为高校人才培养的重要目标.高校图书馆作为信息积累和交流的平台,在素质教育过程中发挥着重要作用.论述了高校图书馆在素质教育中的作用,并提出了利用图书馆丰富资源,搭建高校素质教育平台的几点建议.     

上充泵零流量管线安全阀波纹管破裂原因分析及处理

分析了上充泵零流量管线安全阀波纹管多次破裂的原因。论述了系统中两个安全阀出口并联且相距较近是引起安全阀颤震并导致波纹管破裂的主要原因。提出了从设计上采取控制振动源——及时发现下泄流量过滤器压差超标和处理过滤器堵塞的有效处理措施。解决了安全阀波纹管的破裂问题。     

Contribution to the elucidation of the structure of the bacterial flagellum nano-motor through AFM imaging of the M-Ring

The flagellar nano-motor of bacteria is one of the most interesting and amazing natural nano-machine. Despite its discovery 30 years ago, some details of its structure and mechanisms are not yet elucidated. Several studies have revealed some important aspects of its structure and numerous data are available today; however, the inner mechanisms of the nano-motor have not been yet resolved, partially due to the lack of information about the 3D assembly, shape and interactions of the different parts in experimental environment as close as possible as the native cellular conditions. We have developed an approach using atomic force microscopy imaging in liquid media, which allows us to study part of the motor in native liquid environment. In this work, we are interested in the FliG proteins, identified as the key functional proteins of this nano-machine. We report 3D images of their assembly on surfaces, which could be representative of the so-called M-ring part of the nano-motor. These images have been acquired on both mica surfaces and on supported bilayer membranes mimetics of E. coli native membrane. The systematic analysis of the shape and the size of different recorded assemblies made us believe that the FliG organization we observed could lead to a new model for the structure and mechanism of the flagellar nano-motor.     

图像采集卡对光学仪器性能数字化检测的影响研究

从介绍图像采集卡在光学仪器性能检测过程中的作用出发 ,详细分析了图像采集卡影响检测结果可信度的若干因素 ,并给出了一个图像采集卡的应用实例