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新型调压室差动孔尺寸变化对水力过渡过程的影响 被引量:1
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作者 张彦航 张晓宏 +1 位作者 夏祥乾 赵正飞 《水资源与水工程学报》 2010年第6期151-154,共4页
结合新型组合调压室阻抗式、溢流式和差动式的特点,建立了的基本方程及边界条件,结合算例对新型组合式调压室差动孔尺寸变化对隧道末端压力、调压室涌浪水位、蜗壳末端压力的影响进行了分析。结果表明:差动孔尺寸变化对新型组合式调压... 结合新型组合调压室阻抗式、溢流式和差动式的特点,建立了的基本方程及边界条件,结合算例对新型组合式调压室差动孔尺寸变化对隧道末端压力、调压室涌浪水位、蜗壳末端压力的影响进行了分析。结果表明:差动孔尺寸变化对新型组合式调压室水力过渡过程具有一定的影响,其结论对进一步研究新型组合式调压室过渡过程有良好的指导作用,对推进新型组合式调压室在水电站中的应用有很大帮助。 展开更多
关键词 新型组合式调压室 差动孔 隧道末端压力 涌浪水位 蜗壳压力
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组合式差动调压室差动孔敏感性分析 被引量:1
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作者 曹阳 张晓宏 张俊发 《水资源与水工程学报》 CSCD 2019年第3期189-193,共5页
针对带有连接管、竖井和差动上室的组合式差动调压室,结合某长引水式电站工程实例进行仿真计算,研究差动孔流量系数组合对调压室工作性能及有压引水系统的影响。通过对调压室涌浪变化过程、机组转速升高率及蜗壳末端压力计算成果的分析... 针对带有连接管、竖井和差动上室的组合式差动调压室,结合某长引水式电站工程实例进行仿真计算,研究差动孔流量系数组合对调压室工作性能及有压引水系统的影响。通过对调压室涌浪变化过程、机组转速升高率及蜗壳末端压力计算成果的分析,得出只有在合适的差动孔流量系数组合下,才能充分发挥上室和升管的作用,进而提高调压室的工作性能。其结论对进一步研究该组合式差动调压室水力过渡过程具有一定实际意义,对推进该型式调压室在实际工程中的应用具有积极作用。 展开更多
关键词 组合式差动调压室 差动孔 流量系数 调压室涌浪 蜗壳压力
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Evidence of Hydropassive Movement in Stomatal Oscillations of Glycyrrhiza inflata under Desert Conditions 被引量:8
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作者 王根轩 廖建雄 吴冬秀 《Acta Botanica Sinica》 CSCD 2001年第1期41-45,共5页
Stomatal conductance was found to change from steady-state to a slate of oscillations during daytime when vapour pressure deficit (VPD) increased to a value of 1 kPa in Glycyrrhiza inflata Batalin grown under the cond... Stomatal conductance was found to change from steady-state to a slate of oscillations during daytime when vapour pressure deficit (VPD) increased to a value of 1 kPa in Glycyrrhiza inflata Batalin grown under the conditions of arid desert in north-west China. The injected metabolic inhibitors (NaN3 or carbonyl cyanide-m-chlorophenyl-hydrazone (CCCP)) slightly reduced the stomatal conductance but did not significantly decrease the intensity of stomatal oscillations (amplitude/average). The oscillation intensity was found to he significantly correlated with VPD and root resistance, but not with the respiration rate. There might exist a minimum threshold of VPD (0.8 kPa) and root resistance (1/4 relative value) that induced stomatal oscillations. These results suggested that stomatal oscillations induced by atmospheric drought stress and root resistance were mainly a type of hydropassive movement. 展开更多
关键词 stomatal oscillations Glycyrrhiza inflata hydropassive movement stomatal conductance vapour pressure deficit
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Effects of pinholes on zerooffset of single-axis normal-tracking measurement system
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作者 LI Huai-lu WANG Zhong +1 位作者 KANG Yan-hui FU Lu-hua 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第4期336-341,共6页
A single-axis normal-tracking measurement system is proposed, which can solve the problem of measuring large curved surface. According to Collins formula, the tilt dependent error of the measurement system is studied,... A single-axis normal-tracking measurement system is proposed, which can solve the problem of measuring large curved surface. According to Collins formula, the tilt dependent error of the measurement system is studied, which uses Gaussian beam as the light source. By theoretical analysis and numerical simulation, the influence of the error is presented. The results show that there is the difference between point source and Gaussian beam for differential confocal microscopy. The opti-mal diameter of pinhole can be determined by the mathematical model and the actual parameters of the measurement system. The optimal pinhole diameter of this measurement system is 20 to 35 pm for 633 nm wavelength light source. 展开更多
关键词 differential confocal microscopy Gaussian beam Collins formula pinhole optimum
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