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恒河水库消能方式研究
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作者 华钲森 赵玮 付登辉 《陕西水利》 2024年第10期133-137,141,共6页
坝体消能在水库枢纽设计中往往是较为重要的一部分,通常需要结合大坝的泄水方式、流量大小、地形地质条件、工程投资,结合水力计算并参考以往已建工程的消能工设计,进行消能方式选择,后续依据水工模型试验再进行布置方式及体型的优化,... 坝体消能在水库枢纽设计中往往是较为重要的一部分,通常需要结合大坝的泄水方式、流量大小、地形地质条件、工程投资,结合水力计算并参考以往已建工程的消能工设计,进行消能方式选择,后续依据水工模型试验再进行布置方式及体型的优化,完成消能设计。依据地形地质条件、结合水力计算与工程投资,经模型试验验证,设计方案合理,可为类似案例提供借鉴。 展开更多
关键词 底流 力池 挑流 消能比 模型试验
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二级洞塞泄流的消能特性分析 被引量:5
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作者 尹则高 朱慧洁 +2 位作者 曹先伟 陈更 郑清鑫 《排灌机械工程学报》 EI 北大核心 2012年第1期85-90,共6页
为了分析二级洞塞泄流的消能特性,揭示洞塞几何体形参数对洞塞泄流消能效果的影响规律,运用三维RNG k-ε紊流数学模型对洞塞泄流进行了数值模拟.建立了洞塞泄流的室内物理模型试验,利用模型试验结果对数学模型进行了验证,两者吻合较好.... 为了分析二级洞塞泄流的消能特性,揭示洞塞几何体形参数对洞塞泄流消能效果的影响规律,运用三维RNG k-ε紊流数学模型对洞塞泄流进行了数值模拟.建立了洞塞泄流的室内物理模型试验,利用模型试验结果对数学模型进行了验证,两者吻合较好.第1和第2级洞塞面积收缩比分别取为0.2,0.3,0.4和0.5,第1和第2级洞塞相对长度相等并分别取为0.5,1.5和3,形成144种工况.利用验证后的数学模型对上述144种工况进行计算和分析.结果表明:第1和第2级洞塞面积收缩比对消能率和消能比的影响较大,而相对长度对其影响很小.在其他几何体型参数一定的情况下,随着第2级洞塞面积收缩比的增大,第1级洞塞消能率和消能比相应增大,第2级洞塞消能率和消能比相应降低.在其他几何体型参数一定的情况下,随着第1级洞塞面积收缩比的增大,第1级洞塞消能率和消能比相应降低;第2级洞塞消能率变化不大,而消能比相应增加.当第1和第2级洞塞面积收缩比分别达到最小时,消能率达到最大. 展开更多
关键词 二级洞塞 面积收缩比 相对长度 能率 消能比
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Electrogastrography associated with symptomatic changes after prokinetic drug treatment for functional dyspepsia 被引量:11
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作者 Hyun Chul Lim Sang In Lee +1 位作者 Jiande DZ Chen Hyojin Park 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第41期5948-5956,共9页
AIM:To evaluate the effect of prokinetic drugs on electrogastrography(EGG) parameters according to symptomatic changes in patients with functional dyspepsia(FD).METHODS:Seventy-four patients with FD were prospectively... AIM:To evaluate the effect of prokinetic drugs on electrogastrography(EGG) parameters according to symptomatic changes in patients with functional dyspepsia(FD).METHODS:Seventy-four patients with FD were prospectively enrolled in this study between December 2006 and December 2010.We surveyed the patients using a questionnaire on dyspeptic symptoms before and after an 8-wk course of prokinetic drug treatment.We also measured cutaneous pre-prandial and postprandial EGG recordings including percentage of gastric waves(normogastria,bradygastria,tachygastria),dominant frequency(DF),dominant power(DP),dominant frequency instability coefficient(DFIC),dominant power instability coefficient(DPIC),and the ratio of post-prandial to fasting in DP before and after the 8-wk course of prokinetic drug treatment.RESULTS:Fifty-two patients(70%) achieved symptomatic improvement after prokinetic drug treatment.Patients who had normal gastric slow waves showed symptom improvement group after treatment.Postprandial DF showed a downward trend in the symptom improvement group,especially in the itopride group.Post-prandial DP was increased regardless of symptom improvement,especially in the itopride group and mosapride group.Post-prandial DFIC and DPIC in the symptom improvement group were significantly increased after the treatment.The EGG power ratio was increased after treatment in the symptom improvement group(0.50 ± 0.70 vs 0.93 ± 1.77,P = 0.002),especially in the itopride and levosulpiride groups.CONCLUSION:Prokinetics could improve the symptoms of FD by regulating gastric myoelectrical activity,and EGG could be a useful tool in evaluating the effects of various prokinetics. 展开更多
关键词 ELECTROGASTROGRAPHY Functional dyspepsia ITOPRIDE MOSAPRIDE Levosulpiride
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A cooperative user selection scheme based on energy efficiency and interference factor in cooperative communication systems 被引量:1
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作者 李萌 Sun Enchang +1 位作者 Yu Fei Richard Zhang Yanhua 《High Technology Letters》 EI CAS 2016年第2期183-191,共9页
With the rapid development of green communications,energy consumption issue plays more and more important role in cooperative communication strategies and communication systems.Based on cooperative transmission model,... With the rapid development of green communications,energy consumption issue plays more and more important role in cooperative communication strategies and communication systems.Based on cooperative transmission model,a cooperative user selection scheme is proposed in consideration of both energy efficiency and interference factor.With the proposed scheme,the selected cooperative user consumes less energy and receives less interference.Furthermore,the main factor is analyzed to affect system performance,including signal-to-noise ratio(SNR)of source user and cooperative user,distance between source user and cooperative user or base station(BS),and fading factor in the transmission model.Through the proposed scheme,energy consumption and influence of interference are jointly taken into account during the cooperative user selection process.Besides,bit error rate(BER)in proposed scheme is also superior to existing schemes.Simulation results are presented to show the performance improvement of the proposed scheme. 展开更多
关键词 green communication cooperative communication energy efficiency interferencefactor
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Optimal Simulation of Distributed Generation System for CO_2-Reduction in Supermarket and Restaurant
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作者 Saori Tajima Tomohiko Mori +1 位作者 Sang-Chul Bae Masafumi Katsuta 《Journal of Energy and Power Engineering》 2014年第11期1848-1858,共11页
After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust he... After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data: distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV (photovoltaic) panel, PCM (phase change material), thermal storage, FCU (fan coil unit) and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size. 展开更多
关键词 Distributed energy supply thermal energy management CO_2 reduction exhaust heat commercial buildings.
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The Energy Balance of the Electro-Hydraulic Linear Actuation System
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作者 M. Herranen K. Huhtala M. Vilenius 《Journal of Energy and Power Engineering》 2010年第8期57-63,共7页
The variable gas exchange valve actuation systems have been developed in order to improve the efficiency of the combustion process. The electro-hydraulic valve actuation (EHVA) systems have good power to weight rati... The variable gas exchange valve actuation systems have been developed in order to improve the efficiency of the combustion process. The electro-hydraulic valve actuation (EHVA) systems have good power to weight ratio, high maximum force and good controllability. The disadvantages are limited frequency bandwidth and energy recovery. Each component of the EHVA system has certain energy consumption, which is characteristic to the component. In this study the power consumptions of the components are investigated by means of the simulation. The investigated components are a hydraulic pump, a hydraulic accumulator, a control valve, and hydraulic lines connecting the components. The pressure losses caused by the oil flow are most significant in the control valves, 50-60% of the total energy consumption. If the stored kinetic energy of the actuator and moving oil masses could be reused, the energy consumption could be up to 25% better. 展开更多
关键词 ENERGY CONSUMPTION ELECTRO-HYDRAULIC variable valve train.
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