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31.
On smoke control for tunnels by longitudinal ventilation   总被引:2,自引:0,他引:2  
Two aspects of smoke control by longitudinal ventilation systems in tunnels is analysed. The first is the increase in air entrainment rate of the plume after operating the system, and the second is the increase in heat release rate as a consequence of increase in air supply rate for combustion. Computational fluid dynamics (CFD) was applied for verifying the study. Keypoints to consider in the design of longitudinal ventilation systems are noted.  相似文献   
32.
谭民 《控制与决策》1994,9(4):266-270,300
本文对CIMS装配线和拆卸线的可靠性问题进行研究。文中分析了它们的运行状况,求出了两种生产线的稳态可用度,并用一个例子加以说明。  相似文献   
33.
In the present study, we showed that simultaneous ligation of the monoclonal antibodies (mAb) against CD6 and CD28 induces T-cell proliferation in purified resting T lymphocytes in the absence of T-cell receptor (TCR) occupancy. No cell proliferation was observed when the mAb were cross-linked alone or used simultaneously in the soluble form. T-cell proliferation mediated through CD6/CD28 is accompanied by the up-regulation of interleukin-2 (IL-2) mRNA and expression of IL-2 receptors on the cell surface. In the presence of IL-2-neutralizing mAb the proliferative response of the T cell induced through CD6/CD28 was inhibited dose dependently. Cross-linking mAb to CD6 and CD28 alone or together did not down-regulate the CD3/TCR complex. T-cell proliferation mediated through CD6/CD28 was only partially blocked by the immunosuppressive drug, cyclosporin A (CsA), whereas anti-CD28-induced T-cell proliferation in the presence of the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), was unaffected. In sharp contrast T-cell proliferation mediated by anti-CD6 in the presence of TPA was efficiently blocked by CsA. In addition, two protein kinase C (PKC) inhibitors, GF 109203X and H-7 dose-dependently inhibited T-cell proliferation mediated through CD6/CD28, suggesting that PKC activation may be involved. Furthermore, there was a marked differential dose-dependent inhibitory effect of the PKC inhibitors on T-cell proliferation mediated by the co-ligation of anti-CD6 or anti-CD28 in the presence of anti-CD3, with the former being more sensitive to PKC inhibition. Taken collectively, our results suggest that T-cell activation can occur through an antigen-independent pathway by cross-linking the accessory molecules, CD6 and CD28, and that these two cell surface antigens may have distinct signalling pathways.  相似文献   
34.
疏松桂  谭民 《控制与决策》1994,9(6):451-454
本文利用等效工作站理论和工件流平衡原理,推导出非串行离散事件生产线可以等价于串联系统,并归结为装配和拆卸两条定理,解决了系统的建模、分析与设计问题。  相似文献   
35.
In this study, four similar bench-scale submerged Anoxic/Oxic Membrane Bioreactors (MBR) were used simultaneously to investigate the effects of solids retention time (SRT) on organic and nitrogen removal in MBR for treating domestic wastewater. COD removal efficiencies in all reactors were consistently above 94% under steady state conditions. Complete conversion of NH(4+)-N to NO(3-)-N was readily achieved over a feed NH(4+)-N concentration range of 30 to 50 mg/L. It was also observed that SRT did not significantly affect the nitrification in the MBR systems investigated. The average denitrification efficiencies for the 3, 5, 10 and 20 days SRT operations were 43.9, 32.6, 47.5 and 66.5%, respectively. In general, the average effluent nitrogen concentrations, which were mainly nitrate, were about 22.2, 27.6, 21.7 and 13.9 mg/L for the 3, 5, 10 and 20 days SRT systems, respectively. The rate of membrane fouling at 3 days SRT operation was more rapid than that observed at 5 days SRT. No fouling was noted in the 10 days and 20 days SRT systems during the entire period of study.  相似文献   
36.
目前采气井站的安全教育培训工作取得了一定成绩,但也存在不少问题。针对这些问题,提出了3点对策建议:制定长期系统的安全培训计划;建立教育培训信息反馈机制;培训方法不断改进与创新。  相似文献   
37.
Years have lapsed since the inauguration of the first Wireless Application Protocol (WAP) application. One of the main reasons for the lukewarm response so far may be attributed to the lack of a “Killer” application. Many companies and developers have attempted to replicate email services (an Internet Killer appplication) within the WAP realm, but till now, no significant success has been reported. This paper will first discuss on the key functions which are lacking in the present WAP-email service, and which are arguably necessary if a much larger user base is to be attracted to these services. A new system will be proposed which can enable the user to send files residing in a remote personal computer (PC) as attachments to his emails using WAP-enabled mobile devices. The implementation of the system will be presented in details. Issue relating to the connection to various types of email servers and the security of the system will also be addressed in the paper.  相似文献   
38.
In addition to satisfying several competing objectives, many real-world applications are also characterized by a certain degree of noise, manifesting itself in the form of signal distortion or uncertain information. In this paper, extensive studies are carried out to examine the impact of noisy environments in evolutionary multiobjective optimization. Three noise-handling features are then proposed based upon the analysis of empirical results, including an experiential learning directed perturbation operator that adapts the magnitude and direction of variation according to past experiences for fast convergence, a gene adaptation selection strategy that helps the evolutionary search in escaping from local optima or premature convergence, and a possibilistic archiving model based on the concept of possibility and necessity measures to deal with problem of uncertainties. In addition, the performances of various multiobjective evolutionary algorithms in noisy environments, as well as the robustness and effectiveness of the proposed features are examined based upon five benchmark problems characterized by different difficulties in local optimality, nonuniformity, discontinuity, and nonconvexity  相似文献   
39.
本文以淄博广电总台7 1讯道数字分量转播车为例,浅谈该车的视频、音频系统以及设备配置情况.  相似文献   
40.
杭州-宁波天然气输气管道工程(简称杭-宁输气管道工程)是浙江省天然气长输管网主干线之一,根据工程河流穿越众多、渠塘穿越频繁的特点,对杭-宁输气管道工程水域穿越的特点和穿越方式作了总结;重点分析了水域定向钻穿越设计及需要注意的问题,为今后浙江省天然气管网建设的水域穿越设计作了探讨。  相似文献   
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