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101.
A. R. Kacimov 《Canadian Metallurgical Quarterly》2008,134(1):101-106
A channel or axisymmetric dimple filled with a coarse porous material and aimed at a temporary storage of infiltrated water as a perched water table aquifer is studied. The bottom shape is varied based on the criterion of maximal water storage after a certain period of drainage and evaporation. Leakage into the vadose zone through a thin liner occurs with a specific discharge proportional to the pressure drop across the liner. Evaporation through a horizontal shrinking water table is spatially uniform. An ordinary differential equation, which follows from the mass balance condition, is solved either explicitly or numerically. The class of triangular, polynomial, and conical sections is studied. The shape of maximal water retention is calculated for a given initial stored water volume or water table width, evaporation intensity, liner thickness and conductivity, vadose zone pressure beneath the liner, and selected time interval between two sequential infiltration events. 相似文献
102.
液压系统的泄漏,噪声及安装技术探讨 总被引:1,自引:0,他引:1
本文探讨了液压技术中的三个问题:泄漏,噪声及液压系统安装。这几个问题处理得不好会直接影响产品或系统的质量和可靠性。 相似文献
103.
Quenching and blowoff limits of hydrogen diffusion flames on small burners were observed. Four burner types, with diameters as small as 8 μm, were considered: pinhole burners, curved-wall burners, tube burners, and leaky fittings. In terms of mass flow rate, hydrogen had a lower quenching limit and a higher blowoff limit than either methane or propane. Hydrogen flames at their quenching limits were the weakest flames recorded to date, with mass flow rates and heat release rates as low as 3.9 μg/s and 0.46 W. The quenching limit for a hydrogen flame at a 6 mm leaky compression fitting was found to be 28 μg/s. This limit was independent of supply pressure (up to 131 bar) and about an order of magnitude lower than the corresponding limits for methane and propane. 相似文献
104.
The study of ultrathin ZrO2 films grown on surface passivated germanium substrates by plasma enhanced Atomic Layer Deposition (PEALD) has been carried out. Nitride passivation has been used to form an interfacial layer between ZrO2/Ge. The ultra-thin ZrO2 film deposited with thickness of ~5.75 nm and refractive index of ~2.05 as observed through ellipsometry. The Ge3d, Zr3d, N1s and O1s are XPS core level spectra's confirm the formation of GeON and ZrO2 ultra-thin films. The AFM results show the roughness of deposited films as low as 0.3 nm. The effect of post metallization annealing (PMA) on electrical properties of Au/Cr/ZrO2/GeON/Ge capacitors has been investigated. The improvement in k value (~38) and an EOT value (~0.5 nm) after PMA on Ge/GeON/ZrO2 stack has been observed. The flat band voltage and hysteresis of post metallization annealed devices has been reduced as compared to that of without PMA GeON/ZrO2 stack. 相似文献
105.
张俊朋 《化学工业与工程技术》2007,28(4):49-51
简述了大庆油田化工有限公司二甲醇装置原中压废热锅炉投入运行以来出现的泄漏问题,分析了泄漏的原因,并对其进行了技术改造,总结了改造后的应用效果。 相似文献
106.
Plastic encapsulated packages exhibit high leakage currents after a few hundred hours in the steam pressure pot test (SPP).
The present study investigates two possible causes of leakage current. These are: (a) mold compound, (b) the polyimide tape
used for co-planarity of lead frame fingers. The results of this study indicate that the leakage cur-rent is independent of
the frame and is not caused by the mold compound. The data indicates that it is the ionic content and acrylic-based adhesive
layer of the polyimide tape which cause the leakage current. To eliminate the leakage current, polyimide tape with low ionic
content and non acrylic-based adhesive should be used.
*Permanent address: School of Physics, Universiti Sains Ma-laysia, 11800 USM Penang, Malaysia. 相似文献
107.
F. J-C. Bouchart H. M. Salleh J. W. Sawkins P. W. Jowitt 《Water and Environment Journal》2001,15(1):21-26
During the last few years, the introduction of mandatory leakage targets for UK water companies has had the positive effect of reducing levels of leakage, while requiring the companies to operate at an economic level of leakage. Unfortunately, the determination of company-specific economic levels of leakage have been a source of disagreement between the water companies and the Government, with the Government view that water companies are not using the true long-term marginal costs of water abstraction, and therefore are not safeguarding the environment.
This paper (a) reviews the model which was used to define the economic level of leakage, (b) argues the case for resource management based on the impact of water abstractions on the socio-environmental quality of a resource rather than the myopic focus on leakage reductions, (c) presents the concepts of effectiveness and efficiency in relation to socio-environmental quality, and (d) proposes a new methodology which allows the determination of water abstraction rates while maintaining a desired level of socio-environmental quality. 相似文献
This paper (a) reviews the model which was used to define the economic level of leakage, (b) argues the case for resource management based on the impact of water abstractions on the socio-environmental quality of a resource rather than the myopic focus on leakage reductions, (c) presents the concepts of effectiveness and efficiency in relation to socio-environmental quality, and (d) proposes a new methodology which allows the determination of water abstraction rates while maintaining a desired level of socio-environmental quality. 相似文献
108.
汪贤锋 《数字社区&智能家居》2008,(6):1230-1233
本文针对TCP/IP在安全领域的应用展开论述,详细分析了TCP/IP在几个关键地方存在的问题.对其安全漏洞进行了研究,给出了一些建设性的解决办法,为今后的进一步研究奠定了基础。 相似文献
109.
110.
执勤车辆是消防装备的核心,具有基础性、平台性、战略性的重要地位,当前人员装备投送方式正由摩托化向机械化转变,同时又向信息化数字化智能化方向发展,所以车辆配备关系到消防救援队伍能否加快转型升级成为有效生成战斗力.文章简要分析了当前消防救援队伍执勤车辆配备的现状发展趋势,结合当今技术发展,论述执勤消防车辆配备可能存在的机遇和挑战. 相似文献