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引大入秦灌区自压半固定喷灌工程设计
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作者 熊伟 《甘肃水利水电技术》 2002年第4期281-282,共2页
自压喷灌具有节水效果好、一次性投入低、运行费用省等优点 ,是山丘区节水灌溉的好方法。引大灌区地形复杂 ,地貌多样 ,中低山丘陵区占灌溉面积近 4 0 % ,这些地区地形坡度和落差较大 ,土质好 ,应优先发展自压喷灌工程。重点对引大灌区... 自压喷灌具有节水效果好、一次性投入低、运行费用省等优点 ,是山丘区节水灌溉的好方法。引大灌区地形复杂 ,地貌多样 ,中低山丘陵区占灌溉面积近 4 0 % ,这些地区地形坡度和落差较大 ,土质好 ,应优先发展自压喷灌工程。重点对引大灌区自压喷灌的技术条件进行了分析 ,对山丘区自压喷灌的基本参数、设备选定、系统布置方案进行了探讨 ,并从技术经济角度对自压喷灌在引大灌区的适应性进行了分析。 展开更多
关键词 引大入秦灌区 自压喷灌 自压条件 系统布置 设计 效益分析
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Applicability of Some Stomatal Models to Natural Conditions 被引量:4
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作者 于强 刘建栋 罗毅 《Acta Botanica Sinica》 CSCD 2000年第2期203-206,共4页
Under natural conditions, the use of vapor pressure deficit between mesophyll cell surface and ambient air ( VPD s ) instead of atmospheric humidity factors in some stomatal models may markedly promote the applicabil... Under natural conditions, the use of vapor pressure deficit between mesophyll cell surface and ambient air ( VPD s ) instead of atmospheric humidity factors in some stomatal models may markedly promote the applicability of stomatal models. It has been pointed out from theoretical analysis that the expression of the responses of stomatal conductance to VPD s is equivalent to the expression of responses of stomatal conductance to water loss of transpiration in stomatal models. 展开更多
关键词 stomatal conductance MODEL
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CFD simulation of spontaneous coal combustion in irregular patterns of goaf with multiple points of leaking air 被引量:5
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作者 LI Zong-xiang 《Journal of China University of Mining and Technology》 EI 2008年第4期504-508,515,共6页
Based on the non-linear air leakage seepage equation for an anisotropic porous medium, on the seepage diffusion equation of multicomponent gas and on the seepage synthetic heat transfer equation of a porous medium, th... Based on the non-linear air leakage seepage equation for an anisotropic porous medium, on the seepage diffusion equation of multicomponent gas and on the seepage synthetic heat transfer equation of a porous medium, the numerical model for field flow problems of irregular patterns of a goaf with multiple points of leaking air is established and simultaneously solved by the upwind mode finite element method (G3 computer program). According to the complexity of irregular patterns of a goaf with multiple points of leaking air, the flow pattern in a large area of such a goaf and the variation in gases of methane, oxygen and CO and in temperature are theoretically described. In the calculation, the goaf is regarded as a caving anisotropic medium and the coupling effect of methane effusion on spontaneous combustion is considered. The simulation results agree well with practical experience. In addition, the spontaneous combustion process is also simulated, indicating that 1) the spontaneous combustion often takes place near the area where fresh air leaks in and 2) the fire sources can be classified into static and dynamic zones. Therefore, in practical fire preventing and extinguishing, we should clearly distinguish the upstream air leaking points from the downstream ones in order to take proper measures for leakage stopping. 展开更多
关键词 irregular pattern of goaf multi-points of air leaking spontaneous combustion temperature field fire zone distribution pressure balance
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Clinical application of full automatic animal experimental cabin of normobaric/hypobaric hypoxia and high carbon dioxide
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作者 Wang Qing Chong Yinbao Zhao An Liu Jiuling 《Journal of Medical Colleges of PLA(China)》 CAS 2010年第2期91-97,共7页
To explore the feasibility of the full automatic animal experimental cabin to establish the animal models in normobaric/hypobaric hypoxic and high carbon dioxide environment. Methods: Sixty SPF-class male DS rats wer... To explore the feasibility of the full automatic animal experimental cabin to establish the animal models in normobaric/hypobaric hypoxic and high carbon dioxide environment. Methods: Sixty SPF-class male DS rats were divided into 2 groups, 20 for normobaric, hypoxic conditions and the other 40 for hypobaric, hypoxic conditions. For each group, the pulmonary arterial pressure and carotid arterial pressure indicators of rats were examined by using the physiological multi-detector, and the pulmonary vascular changes in the structure were observed. Results: The normobaric/hypobaric hypoxic with high carbon dioxide environment can promote the formation of pulmonary hypertension and accelerate changes in pulmonary vascular remodeling, and promote the right ventricular hypertrophy. Conclusion: Clinical applications showed that the animal experimental cabin has observed and controlled accurately. The result was safe, reliable and reproducible. The cabin can successfully establish the pulmonary hypertension model in normobaric/hypobaric hypoxic with high carbon dioxide environment, and in order to study the physiological mechanism of a variety of circulation and respiratory diseases caused by lack of oxygen, which provided an experimental technology platform for clinical research. 展开更多
关键词 Normobaric/hypobaric hypoxia High carbon dioxide Animal experimental cabin Pulmonary hypertension model
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