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991.
李凯花 《石油化工管理干部学院学报》2003,(4):19-21
推进施工企业党组织的建设必须与时俱进,坚持一岗双责、两个融合、三个同步、四个同时,创新工作思路、工作机制、工作方法和工作方式。把贯彻落实“三个代表”重要思想,作为检验工作成效的根本标准。 相似文献
992.
本文介绍了Wi-Fi标准为解决无线局域网中的安全问题,相继采用的WEP、WPA、802.11i的方法,并分 析了这些方法可能存在的漏洞。同时,文中还进一步分析了VPN技术和入侵技术在无线局域网中的应用和存在的问题。 最后,介绍了我国无线局域网国家标准。 相似文献
993.
Analysis on the effectiveness of the 20-H rule for printed-circuit-board layout to reduce edge-radiated coupling 总被引:1,自引:0,他引:1
Montrose M.I. Er-Ping Li Hong-Fang Jin Wei-Liang Yuan 《Electromagnetic Compatibility, IEEE Transactions on》2005,47(2):227-233
This paper presents the quantified study of the electromagnetic radiation mechanism of the 20-H rule using a numerical approach that has not yet been systematically addressed. The 20-H rule is a rule-of-thumb layout technique recommended to minimize radiated fields propagating from the edges of a printed circuit board (PCB) coupling onto nearby structures. Propagating electromagnetic fields may corrupt adjacent cable assemblies, sheet metal enclosures, and aperture openings. The magnitude of this design rule is investigated using the full-wave finite-difference time-domain (FDTD) method. An analysis on whether benefits exist from use of this rule is examined and under what conditions the rule is valid when correctly implemented. The purpose of this paper is to provide insight into the validity of the 20-H rule, recognizing that every PCB will have different simulation results. FDTD is used to capture a snapshot view of field propagation. This view allows one to determine the validity of the 20-H rule at a single point of time within a dynamic structure and what may be expected when digital components are finally added to a PCB assembly, which generally negates simulated results. 相似文献
994.
Hong Wang Rong Zeng Xiuping Li 《Microwave Theory and Techniques》2005,53(2):564-570
In this paper, RF noise in 0.18-mum NMOSFETs concerning the contribution of carrier heating and hot carrier effect is characterized and analyzed in detail via a novel approach that modulates the channel carrier heating and number of hot carriers using body bias. We confirm qualitatively a negligible role of hot carrier effect on the channel noise in deep-submicrometer MOSFETs. For a device under reverse body bias (Vb), even though the increase in hot carrier population is clearly characterized by dc measurements, the device high-frequency noise is found to be irrelevant to the increase in the channel hot carriers. Experimental results show that the high-frequency noise is slightly reduced with the increase in |Vb|, and can be qualitatively explained by secondary effects such as the suppression of nonequilibrium channel noise and substrate induced noise. The reduction of NFmin and Rn with the increase in |Vb| may provide a possible methodology to finely adjust the device high-frequency noise performance for circuit design 相似文献
995.
996.
In this paper, any two of the three anticorrosion agents, that is emulsifier (OP-10), soluble glass (Na2O·nSiO2) and glycerin (C3H8O3), were treated simultaneously on the surface of amorphous (a-) MgNi+5% Ml2Mg17 (Ml denotes the lanthanum-rich mish metal) electrode and the electrolyte. Effect of the synergistic anticorrosion treatment on charging/discharging cycle stability of the electrode was investigated. Contrasted with single treatment method, the cycling stability of the electrodes was further improved. The desirable synergistic anticorrosion method was that the electrode was treated by the soluble glass, and that OP-10 was added into the electrolyte. The cyclic voltammogram (CV) results of the electrode show clearly that the anticorrosion agent can change the electrochemical activity and mechanism of the electrode. The concentration of the anticorrosion agent in the electrolyte treated by the synergistic anticorrosion method was also investigated. The appropriate concentration of the anticorrosion agents in the electrolyte is 0.143%. 相似文献
997.
998.
Jon T. Carter Paul E. Krajewski Ravi Verma 《JOM Journal of the Minerals, Metals and Materials Society》2008,60(11):77-81
The hot blow forming of magnesium sheet offers significant opportunity for forming complex, lightweight parts for automotive
applications. This paper characterizes the elevated-temperature formability of AZ31 magnesium sheet materials and the effect
of processing conditions on the performance of these materials. In addition, magnesium sheet application development at General
Motors Corporation is reviewed. 相似文献
999.
Toshihiko Hoshide Junpei Fujita 《Journal of Materials Engineering and Performance》2008,17(5):627-632
Strength of ground ceramics may be affected by residual stress as well as surface flaws induced by grinding. Strength prediction
for ground ceramics is convenient for mechanical design of ceramic components. In this article, a numerical procedure based
on fracture mechanics was proposed to estimate strength distribution of ground ceramics by considering grinding-induced residual
stress. Bending strength and residual stress of ground ceramics were measured for three grinding-conditions. By comparison
of simulated results with experimental ones, it was revealed that strength characteristics in experiments were well simulated
by using the proposed procedure. 相似文献
1000.
空心轴液压联轴器内套设计参数的计算分析 总被引:1,自引:0,他引:1
研究了空心轴液压联轴器内套内侧压力沿轴向的变化规律以及压力与对应径向变形位移的比值沿轴向的变化规律,为设计空心轴液压联轴器内套壁厚提供了理论依据。 相似文献