PDM中的关键技术

PDM是有效利用和共享企业信息资源的最佳方案。目前PDM的实施是一个Case -by -Case工程。叙述了PDM系统从开发、实施到在企业中全面运行过程中 ,所涉及到的网络技术、成组技术、数据库技术、组件技术等相关技术的现状、作用和实现方法。提出了方便用户操作的“零输入”方案和加快PDM实施的“零编程”方案。认为PDM成功实施的关键在于系统与企业现状的匹配程度。并预测PDM必然向系统的柔性化和通用化方向发展。     

关于PDM在橡机行业中实施的应用

介绍了PDM系统在橡机行业中的实施，如CAD／PDM封装技术、物料管理、软件实施步骤等。分析了在橡机行业实施PDM的关键点。     

大型企业PDM系统的设计与分析

通过对A集团产品数据管理 (PDM )分系统的设计与分析 ,提出了大型企业集团中PDM的体系结构、集团总部PDM的系统方案和集团范围内PDM的系统规划。这些对于准备实施PDM的大型企业具有很好的借鉴作用     

PDM实施过程中的非技术因素研究

讨论了PDM实施在PDM系统中的重要性,分析了PDM在实施过程中的各种非技术因素,在此基础上建立了PDM分层实施模型,该模型能够清楚表达PDM实施中各种技术和非技术因素的联系,指导PDM在各个阶段的实施,协调实施方和被实施方人员之间的沟通,使实施过程能够在有限的外部资源约束下最大限度地朝着双方所期望的方向发展。     

PDM的选型及实施方案

结合实例介绍了PDM系统实施的必要性、PDM系统的选型、PDM系统的实施方案及实施中需要注意的问题。因为PDM在企业信息集成、提高企业的管理水平以及产品开发效率等方面具有重大意义，所以PDM在企业中的具体应用也越来越受到了人们的关注。     

PDM 快速实施辅助系统

结合PDM技术在我国实施应用的现状，划分了实施的层次水平；深入分析了企业实施PDM的共性与特性；提出了用户相关度的概念，并基于模块化设计原则与用户相关度概念，对PDM开发与实施进行了模块划分与不同相关度分类。在此基础上，提出了PDM快速实施辅助系统的体系结构，阐述了实现该体系结构的关健技术，包括PDM—CAx信息集成的通用模型与通用接口开发技术、PDM与企业全局数据库信息集成的通用接口的实现技术、PDM与企业全局数据库数据模型映射定义工具的实现技术与PDM用户定制系统的开发技术，并给出了各部分的功能结构。     

PDM系统在企业中的应用和实施技术

对产品数据管理（PDM）系统在企业中的应用和实施进行了研究，分析了PDM的功能模型和实施中的一些关键技术，并指出了企业在实施PDM系统时应注意的问题。     

大型企业PDM系统的设计与分析

通过对A集团产品数据管理（PDM）分系统的设计与分析，提出了大型企业集团中PDM的体系结构、集团总部PDM的系统方案和集团范围内PDM的系统规划。这些对于准备实施PDM的大型企业具有很好的借鉴作用。     

PDM系统与ERP系统的集成方法研究与应用

结合PDM系统、ERP系统集成的开发实施,提出了一种基于业务层及数据层集成PDM、ERP系统的集成方法。     

PDM技术及其在CIMS中的应用实施研究

本文介绍了PDM技术的内涵和PDM系统的体系结构,详细论述了PDM技术在CIMS中的应用,分析了PDM和CAD、CAPP、CAM、MRPⅡ的关系,并讨论了PDM应用实施中应该注意的问题。最后对PDM技术的发展趋势进行展望。     

A system for wear prediction in lubricated sliding contacts

A system of analysis is developed to predict the rate of wear in sliding contacts. The essence of the approach is the proposal that the rate of wear can be predicted only in probabilistic terms. Therefore, the estimation of the probability of wear, which can be regarded as synonymous with the probability of surface asperity contacts, precedes the calculation of the wear rate. Further, recognising the fact that wear takes place within the actual area of contact, it is argued that this area consists of plastic and elastic contacts between asperities which, in turn, have different shear strengths and contribute differently to the wear process. In the case of lubricated contact, a frictional film defect represents the influence of a lubricant on the wear process. Moreover, as in this type of contact the load is supported by both lubricating film and contacting asperities, a special procedure is provided to estimate the load supported by the asperities, because it is only that part of the load which contributes to the wear. The catastrophic form of wear in lubricated contacts, that is termed ‘scuffing’, is also considered, and the probability of scuffing, under a given set of operating conditions, is estimated. The predictive system has been tested and its predictions are compared with available experimental results.     

双列调心凹面滚子轴承接触载荷分析

在考虑滚子与套圈、滚子与保持架以及保持架与引导套圈作用力的条件下,建立双列调心凹面滚子轴承动力学模型.以某双列调心凹面滚子轴承为研究对象,与静力学分析模型滚子最大接触载荷计算结果对比,验证了模型的正确性.并分析了工况条件(轴向载荷、径向载荷、倾覆力矩、转速)和结构参数(滚子数量、滚子长度、径向游隙)对滚子最大接触载荷的...     

Histochemical and ultrahistochemical localization of heavy metals in calf organs

Cadmium, zinc, selenium, and copper were administered, singly or in combination, orally or subcutaneously. Experiment I included 32 calves of both sexes; six received Cd (two groups), Zn, Cd, and Zn, and Cd and Se (two groups) and one group was a control. In Experiment II (21 bulls), three were given Cd, Cd, and Cu, and Cd and Zn, respectively, and one group was a control. For light microscopy, in Experiment I the highest amounts of silver granules were present in the samples of liver, small intestine, and vesicular gland of all the exposed groups; in Experiment II the most affected organs were liver, kidney, and small intestine. For electron microscopy, in Experiment I, after administration of Cd and Zn, the highest amounts of granules were seen in the cytoplasm of hepatocytes and cells of the proximal and distal renal tubules and the lowest amounts were found in glandular cells of the pancreas. Administration of Cd and Se resulted in the presence of large numbers of granules in the nuclei and nucleoli of spermatogonies. In Experiment II, ingestion of Cd and Zn in feed led to the appearance of highest amounts of granules in the nucleoli, nuclei, and cytoplasm of cells in testes, kidneys, and pancreas. Following Cd intake, the highest accumulation of granules was observed in the nucleoli of hepatocytes and cells of the proximal and distal renal tubules. Combined Cd and Cu produced the highest number of granules in cells of the proximal and distal renal tubules and in the nucleoli and nuclei of germinal epithelium.     

Immunohistochemical distribution of enkephalin, substance P, and somatostatin in the brainstem of the leopard frog, Rana pipiens

The brainstems of frogs contain many of the neurochemicals that are found in mammals. However, the clustering of nuclei near the ventricles makes it difficult to distinguish individual cell groups. We addressed this problem by combining immunohistochemistry with tract tracing and an analysis of cell morphology to localize neuropeptides within the brainstem of Rana pipiens. We injected a retrograde tracer, Fluoro-Gold, into the spinal cord, and, in the same frog, processed adjacent sections for immunohistochemical location of antibodies to the neuropeptides enkephalin (ENK), substance P (SP), and somatostatin (SOM). SOM+ cells were more widespread than cells containing immunoreactivity (ir) to the other substances. Most reticular nuclei in frog brainstem contained ir to at least one of these chemicals. Cells with SOM ir were found in nucleus (n.) reticularis pontis oralis, n. reticularis magnocellularis, n. reticularis paragigantocellularis, n. reticularis dorsalis, the optic tectum, n. interpeduncularis, and n. solitarius. ENK-containing cell bodies were found in n. reticularis pontis oralis, n. reticularis dorsalis, the nucleus of the solitary tract, and the tectum. The midbrain contained most of the SP+ cells. Six nonreticular nuclei (griseum centrale rhombencephali, n. isthmi, n. profundus mesencephali, n. interpeduncularis, torus semicircularis laminaris, and the tectum) contained ir to one or more of the substances but did not project to the spinal cord. The descending tract of V, and the rubrospinal, reticulospinal, and solitary tracts contained all three peptides as did the n. profundus mesencephali, n. isthmi, and specific tectal layers. Because the distribution of neurochemicals within the frog brainstem is similar to that of amniotes, our results emphasize the large amount of conservation of structure, biochemistry, and possibly function that has occurred in the brainstem, and especially in the phylogenetically old reticular formation.     

Localization of sarcoglycan, neuronal nitric oxide synthase, beta-dystroglycan, and dystrophin molecules in normal skeletal myofiber: triple immunogold labeling electron microscopy.

In order to investigate the mode of existence of the sarcoglycan complex, neuronal nitric oxide synthase (nNOS), beta-dystroglycan, and dystrophin in the normal skeletal myofiber, we examined the ultrastructural localization and mutual spatial relationship of nNOS, beta-dystroglycan, dystrophin, and the individual components of the sarcoglycan complex by using triple immunogold labeling electron microscopy. Each molecule of alpha-, beta-, gamma- and delta-sarcoglycans is located intracellularly or extracellularly near the muscle plasma membrane mostly in accordance with the sarcoglycan antigenic sites against which the antibodies were generated. The association of different two and/or three sarcoglycan molecules out of alpha-, beta-, gamma- and delta-sarcoglycan molecules was frequently observed. Each molecule of nNOS, beta-dystroglycan, and dystrophin was ultrastructurally noted along the cell surface of normal skeletal myofibers. Moreover, the close relation of a sarcoglycan molecule with beta-dystroglycan and dystrophin, and the association of nNOS with dystrophin were also confirmed ultrastructurally. Thus, this study demonstrated that the constituting molecules of the sarcoglycan complex, nNOS, beta-dystroglycan, and dystrophin existed in the form of a cluster at the normal muscle plasma membrane. The association of nNOS with dystrophin and its associated glycoproteins may form a macromolecular signaling complex at the muscle plasma membrane.     

网格曲面上的样条曲线阵列

提出一种流形网格曲面上曲线阵列复制方法,达到曲线重用与再设计的目的。网格曲面上的曲线用测地B样条表示,使对曲线的操作可以转换为对曲线控制顶点的操作;引入离散指数映射理论将给定的源曲线控制顶点映射到切空间,获得它们的法坐标,按照曲线阵列前后控制顶点法坐标保持不变的原则,建立曲线阵列前后控制顶点的对应关系,实现曲线的有规律多重复制。法坐标很好地保持了控制顶点之间的测地距离和相对位置关系,因而也保证了曲线阵列重用过程中的形状保持性。将曲线阵列时的位置与形状分开处理,使曲线生成仅与其所在的局部区域有关而与曲面的整体大小无关,既便于保证曲线的形状保持性,也减少了计算量。试验结果表明,所介绍方法健壮、有效,能满足曲面上曲线的交互设计要求。     

Future directions of fundamental research in additive tribochemistry

This paper reviews briefly the present state of fundamental research, in tribochemistry of load-carrying additives, including oiliness agents, organolsulphur, organochlorine, organophosphorus, organic borates and organometallic compounds. The emphasis is on the weak areas of investigation. It is revealed that the least understood mechanisms, such as the effect of additives on fretting wear, additive-material compatibility, the efficacy of antifatigue additives and the action of water-based fluid additives in metalworking, are the concern of overlapping spheres of learning. A cooperative effort by chemists, metallurgists and mechanical engineers would help overcome the difficulties posed by problems in areas beyond individual expertises. Some research projects for the future are also suggested.     

信号的瀑布分析技术与实现

时间一频率分析即三维瀑布图分析能有效地表达在某一段连续的时间内信号频域的变化情况,比单纯时域或频域分析蕴含了更加丰富的信息,因而常常应用于非平稳随机信号的研究中。在此,首先讨论了瀑布分析在信号分析领域中的重要意义,详细论述了采用DSP进行信号实时处理,PC负责完成三维动态显示方案的技术实现。     

基于XML的空间数据异构共享与在线发布技术研究

本文从空间基础设施的建设过程中出现的问题出发,重点阐述了XML技术在空间信息领域中的三种应用形式-GML、SVG、Web Services的基本概念,并依次介绍了如何将空间数据转换为GML进行传输、存储,SVG显示表达空间数据,以及两者之间如何实现转换。最后介绍了一个具体实例的建设情况,证明了以上技术的可行性。     

Effects of polydatin on the proliferation,migration, and invasion of ovarian cancer

To investigate the effects of polydatin on the proliferation, migration, and invasion of ovarian cancer, the change of proliferative ability, migration ability, and invasive ability of human ovarian cancer cell OVCAR-3, A2780, and HO-8910 was detected by using polydatin and up-regulating PI3K. The anticancer activity and mechanism of polydatin in ovarian cancer were analyzed. Polydatin could effectively inhibit the proliferation, migration, and invasion of OVCAR-3, A2780, and HO-8910, and inhibit the expression of PI3K protein. After the expression level of PI3K protein was up-regulated, the inhibitory effect of polydatin on the proliferative ability, migration ability, and invasive ability of OVCAR-3, A2780, and HO-8910 significantly decreased, suggesting that PI3K was the target of polydatin. Therefore, we concluded that polydatin could inhibit the proliferation, migration, and invasion of ovarian cancer cells by inhibiting the expression of PI3K protein, which provides an experimental basis for polydatin in the treatment of ovarian cancer.