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航天器用齿轮微泵基于流量品质的轻量化设计 被引量:9
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作者 李玉龙 范钧 +3 位作者 刘萍 孙肖霞 潘海成 宋安然 《液压与气动》 北大核心 2020年第8期145-149,共5页
为提高航天器用齿轮微泵的高调速协同性能和降低自身重量的发射成本目的,提出一种基于流量品质的轻量化设计方法,并由所推导出的流量脉动系数公式,构建单一与混合的轻量化模型,最后实例运算与结果分析。结果表明:脉动单一最小化下的齿... 为提高航天器用齿轮微泵的高调速协同性能和降低自身重量的发射成本目的,提出一种基于流量品质的轻量化设计方法,并由所推导出的流量脉动系数公式,构建单一与混合的轻量化模型,最后实例运算与结果分析。结果表明:脉动单一最小化下的齿轮具有0.4044的小宽径比构造,流量品质最好,轻量化程度最差;体积单一最小化下的齿轮具有1.0978的大宽径比构造,轻量化程度最好,流量品质最差;统一最小化下的齿轮具有1.1649更大的宽径比构造,流量品质好,轻量化程度好,抗困油性能好。研究结果对高质量航天器用微泵进一步的研究与开发,具有重要的理论和实践意义。 展开更多
关键词 航天器用齿轮微泵 品质 脉动系数 单位体积 化设计 齿形参数
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深厚淤泥层应用爆破排淤填石法修筑护岸堤
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作者 黄玮 《水利科技》 2013年第4期42-45,共4页
该文根据福州可门火电厂工程地质条件及潮汐特征,在深厚淤泥层(37 m)应用爆破排淤技术修筑护岸堤。依据工程实践,提出水下爆破药量的计算参数,分析爆破对周边环境影响,并对水下爆破排淤处理软基的机理作粗浅探讨,供参考。
关键词 爆破淤处理软基 爆破淤单位体积淤泥耗药 爆破安全 护岸堤
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液态CO_2压裂技术与工艺研究 被引量:1
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作者 张世春 《石油化工应用》 CAS 2017年第11期59-61,共3页
本文通过对液态CO_2压裂关键技术要求做了介绍,并结合现场压裂初期的非稳态变化过程和稳定状态进行分析,对液态CO_2压裂技术在油气田的现场应用提供参考。
关键词 液态CO2压裂 体积排量 黏度
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Change of Arctic sea-ice volume and its relationship with sea-ice extent in CMIP5 simulations 被引量:1
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作者 SONG Mi-Rong 《Atmospheric and Oceanic Science Letters》 CSCD 2016年第1期22-30,共9页
The future change of September Arctic sea-ice volume,simulated by 30 state-of-the-art climate models from the Coupled Model Intercomparison Project Phase 5(CMIP5),is examined,which depends on both ice extent and ice... The future change of September Arctic sea-ice volume,simulated by 30 state-of-the-art climate models from the Coupled Model Intercomparison Project Phase 5(CMIP5),is examined,which depends on both ice extent and ice thickness.In comparison with the September sea-ice extent,the September sea-ice volume has larger spread in the historical simulation but faster convergence in the projection simulation,especially in the context of increasing greenhouse gas emissions.This indicates that the ice volume might be more sensitive to external forcings than the ice extent.Using the averaged projection of those climate models from the 30 CMIP5 models that can better reflect the ‘observed' sea-ice volume climatology and variability,it is shown that the September sea ice volume will decrease to ~3000 km3 in the early 2060 s,and then level off under a medium-mitigation scenario.However,it will drop to ~3000 km3 in the early 2040 s and reach a near-zero ice volume in the mid-2070 s under a high-emission scenario.With respect to the historical condition,the reduction of the ice volume,associated with increasing greenhouse gas emissions,is more rapid than that of the ice extent during the twenty-first century. 展开更多
关键词 sea-ice volume sea-ice extent sea-ice thickness cmip5
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Impact of Climate Change and Deforestation on Stream Discharge and Sediment Yield in Phu Luong Watershed, Viet Nam 被引量:3
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作者 D.B. Phan C.C. Wu S.C. Hsieh 《Journal of Environmental Science and Engineering》 2011年第8期1063-1072,共10页
The purpose of this paper is to apply "Soil and Water Assessment Tool (SWAT)" model to assess the impacts of climate change and deforestation on stream discharge and sediment yield from Phu Luong watershed in Nort... The purpose of this paper is to apply "Soil and Water Assessment Tool (SWAT)" model to assess the impacts of climate change and deforestation on stream discharge and sediment yield from Phu Luong watershed in Northern Viet Nam. Among the three climate change scenarios B 1, B2, and A2, representing low, medium, and high levels of greenhouse gas emission, respectively were set up for Viet Nam, the B2 scenario was selected for this study. Two land use scenarios (S1-2030 and $2-2050) were formulated combination with climate change in WSAT simulation. In B2 climate change scenario, mean temperature increases 0.7℃(2030) and 1.3 ℃ (2050); annual rainfall increases 2.1% (2030) and 3.80% (2050) respect to baseline scenario. The results show that the stream discharge is likely to increase in the future during the wet season with increasing threats of sedimentation. 展开更多
关键词 SWAT climate change DEFORESTATION sediment yield stream discharge
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A 3D numerical simulation of laser-induced incandescence of soot particles in coal combustion products 被引量:2
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作者 Ling-hong CHEN Ke-fa CEN +1 位作者 Annie GARO Gerard GREHAN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第9期1320-1326,共7页
Laser-induced incandescence (LII) has received increasing attention as a potentially powerful technique for in-situ measuring of the volume fraction and primary size of soot particles in combustion systems. In this st... Laser-induced incandescence (LII) has received increasing attention as a potentially powerful technique for in-situ measuring of the volume fraction and primary size of soot particles in combustion systems. In this study, a 3D Monte Carlo simulation combined with a Mie equation was developed to analyze the influence of spectral absorption and scattering on the measured LII flux emitted by soot particles. This paper represents a first attempt to analyze soot measurement using the LII technique in coal combustion products. The combustion products of gases (CO2, N2), soot, and fly-ash particles, present between the location of laser-excited soot and the LII flux receiver. The simulation results indicated that an almost Beer-Lambert exponential decrease in LII flux occurred with an increase in the volume fraction of soot particles, while a nearly linear decrease occurred with an increase in the volume fraction of fly-ash particles. The results also showed that scattering effects of both soot and fly-ash particles on the LII flux could be neglected. Compared with the absorption of gases, a decrease of 20% of LII flux was observed with soot particles, and a decrease of 10% with fly-ash particles. 展开更多
关键词 Laser-induced incandescence (LII) SOOT FLY-ASH 3D Monte Carlo SCATTERING ABSORPTION
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