Wear resistance of plasma coatings for a constant work of friction

We analyze the wear resistance of plasma coatings for a constant work of friction. The dependences of the wear resistance of the coatings are obtained for a broad range of loading conditions. It is shown that the minimum sensitivity to loading conditions is exhibited by the molybdenum coatings. It is also established that the wear resistance of the coatings decreases as the amplitude of displacements increases and the cyclic frequency of the tests decreases due to the intensification of fatigue processes on the surfaces. The comparative characteristics of coatings are presented. __________ Translated from Problemy Prochnosti, No. 5, pp. 94–100, September–October, 2007.     

20世纪后半叶法国大学内部管理结构问题研究

20世纪后半叶是法国大学内部管理结构由雏形到成形的时期。在此过程中形成了一套完整的大学内部管理结构体系，不过，这一结构体系也存在一些问题。作为法国最大的综合性大学，巴黎大学内部管理结构上的问题透视出法国大学内部管理结构中的不足。本论文尝试着以巴黎大学为个案，分析20世纪后半叶法国大学在内部管理结构中的问题，尤其是高校内部两大团体之间的权力消长关系，以期对我国大学内部管理结构建设有所启示。     

Experimental methods for measuring the oil-film thickness between the piston-rings and cylinder-wall of internal combustion engines

Computer models of the lubrication of piston-rings in internal combustion engines normally present an estimate of the minimum oil-film thickness between ring and cylinder wall as a function of crank angle. As a consequence, experimental measurements of film thickness play a critical role in the verification of theoretical models of piston-ring lubrication. A review is presented of the wide range of techniques that have been used to measure this important variable. The strengths and weaknesses of particular techniques are identified and a number of ways in which the techniques could be developed further are proposed     

Effect of variable friction coefficient on sheet metal drawing

A variable friction model that relates the parameters of sheet metal drawing to the local lubrication conditions taking place during the deformation, has been integrated to a finite element program. Variable friction coefficients for the contacting surfaces are determined from the friction model, which uses the related parameters obtained at each time step of the finite element program as inputs. A number of numerical runs have been performed and the strains are compared with the experimental results for circular blanks. A good agreement is obtained between the numerical and experimental results for the variable friction model used.     

转制科研单位建立和完善内部会计控制的探讨

针对目前大多数科研单位在内部会计控制中存在的问题,根据财政部颁布的《内部会计控制规范一基本规范》,探讨了科研单位在转制过程中应如何建立和完善内部会计控制制度,以达到防范经营风险,保护资产安全、完整,确保经营管理目标和政策有效实施.     

钢管减阻型内涂层生产工艺及设备

介绍了钢管减阻型内涂层技术的生产工艺和主要设备，给出了内涂层生产线典型的工艺布置，并对主要设备的组成及工作原理进行了介绍。     

Determination of friction coefficient encountered in large deformation processes

A new technique, namely, the open-die backward extrusion test technique, was developed as an alternative method to the ring compression test in order to quantitatively evaluate the coefficient of friction, μ, at the die/workpiece interface. This technique relates the percentage deformation in height of the specimen to the percentage increase in extruded height of the specimen. In this study, the open-die backward extrusion tests (ODBET) were simulated for different aspect ratios, (H/D), and different die geometries, (d/D), by utilizing an elastic-plastic finite element code (ANSYS) in order to obtain the friction calibration curves (FCCs). The results indicated that the extruded height is related to the friction conditions at the die/workpiece interface. Therefore, ODBET can be used to generate FCCs to determine the coefficient of friction at the die/workpiece interface in large deformation processes.     

THE SIMULATION OF THE SAR IMAGE OF INTERNAL SOLITARY WAVES IN ALBORAN SEA

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＯｃｅａｎｉｎｔｅｒｎａｌｗａｖｅｉｓａｋｉｎｄｏｆｇｒａｖｉｔｙｗａｖｅｇｅｎｅｒａｔｅｄｉｎｔｈｅｓｔｒａｔｉｆｉｅｄｏｃｅａｎ .Ｉｔｐｒｏｄｕｃｅｂｙｔｈｅｉｎｔｅｒａｃｔｉｏｎｏｆｔｉｄｅｃｕｒｒｅｎｔａｎｄｔｏｐｏｇｒａｐｈｙ ,ｓｅａｑｕａｋｅａｎｄｍｏｖｉｎｇｓｈｉｐｗｈｅｎｔｈｅｓｔｒｏｎｇ ,ｓｈａｌｌｏｗｐｙｃｎｏｃｌｉｎｅｉｓ ｐｒｅｓｅｎｔ.Ｔｈｅｉｎｔｅｒｎａｌｗａｖｅｓｉｎｔｈｅｃｏｎｔｉｎｅｎｔａｌｓｈｅｌｆａｒｅａｌｍｏｓｔｔｉｄｅｐｒｏｄ…     

湛江发电厂一号机振动的原因分析及处理

对湛江发电厂1号机4号轴瓦振动大的问题进行分析,认为其主要原因为:低压缸变形大导致动静碰摩,轴承座及盘车箱下部脱空引起刚度降低,轴承座的固有频率与工频相近等。对此,采取了相应的处理措施,实施后4号轴瓦振动得到有效解决。     

小型全内腔脉冲Ar~＋激光管的研制

介绍一种小型全内腔脉冲Ａｒ＋激光管的设计和结构。并对不同阴极，放电管直径，激励电压及Ａｒ气压等对输出功率及激光管寿命的影响作了一系列的实验，试制出结构简单，使用方便，价格便宜的有一定实用价值的小型全内脏脉冲Ａｒ＋激光管。