某大学电子商务专业WEB教学试验模拟平台及课程设计

本文描述某大学电子商务专业通过校企合作,引入专业软件辅助教学的过程,包括教学目的、系统架构、授课安排等。     

基于HCPN的发电企业项目管理工作流建模

如何对工程项目的成本、进度、质量情况进行控制和跟踪是发电企业的重要问题,应用工作流可通过对业务流程的整合及资源的合理分配解决这一问题。本文基于分层着色Petri网(HCPN),将工作流过程模型的逻辑结构和语义与HCPN中的网结构进行映射,进而利用CPN-TOOLS定义基于HCPN的项目管理工作流过程模型,并利用化简原则对工作流模型进行畅通性验证。     

基于LabVIEW的高温超导脉冲功率状态监控系统

脉冲功率数据采集系统是确保脉冲功率系统稳定安全运行的关键之一,超导脉冲功率系统由超导储能系统和外部放电电路组成。本文设计了基于LabVIEW的超导脉冲功率状态监控系统,该系统由多路传感器、信号调理电路和高精度数据采集系统构成,实现了对超导脉冲功率系统各个数据的精确采集,并利用虚拟仪器强大的数据处理能力,实现了对超导脉冲功率系统运行状态的准确判断,实验结果表明设计的状态监控系统能够有效地监控高温超导脉冲功率系统的运行状态。     

Detection of defects in a grout curtain by geophysical methods

Conclusion The proposed method of detecting local defects in a cutoff curtain has a large radius of investigation and allows testing a 30-m-long section of the curtain during one experiment.Each experiment takes about 4 h. The area of use is limited to an evaluation of the quality of grout curtains constructed below the groundwater level. The method is intended for use together with other existing methods for increasing the details of checking grout curtains.In addition to a qualitative solution of the quality control problem (detection of local defects in the grout curtain), the method makes it possible to obtain a quantitative evaluation of the achieved effect based on solving the problem of the relation between the measured parameter and effect of grouting obtained for a homogeneous (porous) medium.The use of the described geophysical method of checking the quality of grout curtains makes it possible to increase the reliability of their work and to promptly introduce necessary changes into the grouting technology.Translated from Gidrotekhnickeskoe Stroitel'stvo, No. 7, pp. 23–27, July, 1986.     

Strength characteristics of the materials obtained by hot forging of porous powder preforms. II. Effect of heat treatment on the tensile and shear strength and the compressive yield stress

Conclusions Annealing of the powder metallurgy steels leads to a reduction in the values of the parameters _t, , and ^c _0.2. During this process, they become lower than those of the hot rolled (worked) products. However, after annealing, the stability of all the three characteristics increases. Quenching followed by a low-temperature tempering improves the parameters _t, , and ^c _0.2, but in this case, brittleness of the material increases. With increasing tempering temperature, all the three parameters decrease and at 600°C, they are virtually at the same level as that obtained after annealing at this temperature.The change in the yield stress after quenching and tempering or after annealing determines to a significant extent the nature (whether brittle or ductile) of shear fracture.Translated from Poroshkovaya Metallurgiya, No. 4(280), pp. 73–75, April, 1986.     

Effect of composition and porosity on the hardenability and hardness penetration of structural powder steels

Conclusions The effect of porosity ( > 10%) on the hardenability of the powder steels is stronger than the effect of carbon content. The role of these factors changes with the reduction of porosity ( < 10%) and the carbon content exerts a stronger effect on the hardenability of the steel. After hot pressing, the hardenability of the powder steels approaches the hard-enability of the dense steels of a similar chemical composition.The hardenability of the alloy powder steels at a constant carbon content and porosity is independent of the degree of alloying of the steel.The strength of the effect of complex alloying on the hardness penetration of the powder steels increases with decreasing porosity, especially after hot pressing and annealing as a result of the more efficient homogenizing of the structure with respect to carbon and alloying elements.Translated from Poroshkovaya Metallurgiya, No. 1(277), pp. 82–86, January, 1986.     

Development of tungsten-carbide-base corrosion-resistant composite materials with a binder of PKh8N15 stainless steel

Conclusions The bend strength of VNS20 and VNS32 composites is determined by the quantity of ₁phase and depends little upon the content of binder (PKhl8N15 steel). The hardness, on the other hand, depends substantially upon both the ₁-phase content and upon the quantity of binder.The VNS20 and VNS32 composites sintered at the temperatures of the start of formation of the liquid phase in the tungsten carbide—PKhl8N15 steel system, when compaction is completed and the rate of formation of ₁-phase is still insignificant, have the optimum properties.With a satisfactory level of physicomechanical properties, the VNS20 and VNS32 composites show high corrosion resistance in a medium of nitrine with additions of nitric acid.An increase in the strength of VNS type composites may be obtained by reducing the diffusion reaction of tungsten carbide with stainless steel.Translated from Poroshkovaya Metallurgiya, No. 5(281), pp. 69–75, May, 1986.