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Phenomenon of the sediment deposition in a hydraulic jump region of open channels

Journal of Mountain Science 2022年第7期19卷 1874-1885页

作者： XU wei-lin wang Guo-guang FU Shi-hao wei wang-ru State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China

The hydraulic jump is a typical sudden change for mountain river *** effects of local hydraulic jumps on the particle transport capacity decrease and local flow resistance increase cannot be ignored as the sediment deposition disaster can amplify the flash flood *** present research investigates the influences of a hydraulic jump on the individual particle movement and sediment deposition in a laboratory *** overall processes of a single particle movement are captured by a high-speed *** distribution of sediment deposition along the hydraulic jump is obtained *** results show that both the particle size and the ratio of the upstream and downstream Froude numbers affect the particle motion process.A single particle coming from upstream gradually decelerates and finally stops at the hydraulic jump section because of hydraulic jump *** particle acceleration first increases and then decreases during the time-domain process,and the attenuation trends are fast with the increase of ratio of upstream and downstream of Froude *** increase of the maximum acceleration with sediment flows follows a linear trend approximately,which indicates that the kinetic features of the single sand particle are determined by the coupling effects of the hydraulic jump resistance and the sand dynamic *** the increase of sediment rate and sand particle size,the resistance effect of hydraulic jump on sediment deposition rate along the flow direction gets strong and the sediment deposition area is mainly located upstream of the hydraulic jump *** present study shows that the possible sediment supply upstream must be obtained for identifying the disaster risk combined with the local hydraulic jump *** researches about the detailed critical condition deduced from the relationship between the water flow and sediment deposition are required to confirm and extrapolate present results to other applications.

关键词： Ratio of upstream and downstream Froude

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Analysis on Link Between the Macroscopic and Microscopic Air–Water Properties in Self-Aerated Flows

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China Ocean Engineering 2018年第5期32卷 614-623页

作者： wei wang-ru XU wei-lin DENG Jun TIAN Zhong ZHANG Fa-xing State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

Self-aeration in high-speed free surface flows occurs commonly and is of interest to ocean engineering, hydraulic engineering, and environmental engineering. For two-phase air–water flows, macroscopic air–water flow properties develop gradually, accompanied by the change of microscopic air–water structures. In this article, representational experimental studies on macroscopic and microscopic characteristics of self-aerated open-channel flows are summarized and compared. The isolated effect of the flow Reynolds number and air quantity on the differences in air count rate and chord size are analyzed and discussed. The results show that the characterized flow depth y, affected by the turbulence transfer, is a specific criterion to distinguish the interior air–water structure development. Two distinct linear trends of self-aeration are found, depending on the y/yvariation with a breaking point at Cmean =0.50. The air count rate and size scale in self-aerated flows are affected by the air quantity of self-aerated flows, even with identical flow Reynolds numbers. Thus, a specific parameter is proposed to assess the air–water structures and a series of self-similarity relationships in self-aeration properties are obtained. The link between macroscopic and microscopic air–water properties results in significant scale effect on air–water structures in self-aerated flows.

关键词： self-aeration two-phase flows air concentration air bubble open channel

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Laboratory model study of the effect of aeration on axial velocity attenuation of turbulent jet flows in plunge pool

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Journal of Hydrodynamics 2015年第6期27卷 913-918页

作者：邓军张法星田忠许唯临刘斌卫望汝 State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

In the laboratory model experiment, the velocities of the jet flow along the axis are measured, using the CQY-Z8a velocity-meter. The velocity attenuations of the jet flow along the axis under different conditions are studied. The effects of the aeration concentration, the initial jet velocity at the entry and the thickness of the jet flow on the velocity attenuation of the jet flow are analyzed. It is seen that the velocity attenuation of the jet flow along the axis sees a regular variation. It is demonstrated by the test results that under the experimental conditions, the velocity along the axis decreases linearly. The higher the air concentration is, the faster the velocity will be decayed. The absolute value of the slope K increases with the rise of the air concentration. The relationship can be defined as K = AC~ ＋ Kb. The coefficient A is 0.03 under the experimental conditions. With the low air concentration of the jet flow, the thinner the jet flow is, the faster the velocity will be decayed. With the increase of the air concentra- tion, the influence of the thickness of the jet flow on the velocity attenuation is reduced. When the air concentration is increased to a certain value, the thickness of the jet flow may not have any influence on the velocity attenuation. The initial jet velocity itself at the entry has no influence on the variation of the velocity attenuation as the curves of the velocity attenuation at different velocities at the entry are practically parallel, even coinciding one with another. Therefore, improving the air concentration of the jet flow and disper- sing the jet flow in the plunge pool could reduce the influence of the jet flow on the scour.

关键词： jet flow air concentration velocity

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Fast species identification of mycobacterium by rpoB gene chip technology

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Journal of Life Sciences 2009年第5期3卷 43-46页

作者： LI Hong-min FAN Bo wang wei AN Hui-ru MIAO Qing Tuberculosis Research Laboratory The Second Clinical Department of the PLA General Hospital Beijing 100091 China

Based on rpoB gene micro array as target gene, we are going to use gene chip technology to test 24 mycobacterium standard specimens, 8 non-mycobacterium specimens and 86 mycobacterium clinical isolated specimens. As a result, after mycobacterium and non-mycobacterium standard specimens were duplicated by PCR, mycobacterium standard specimens reproduced 360bp DNA fragments; on the other hand, non-mycobacterium specimens did not reproduce any fragments except for hemolytic streptococcus and corynebacterium pseudodiphtheriticum which had the same results as mycobacterium standard specimens. Sensitive test is able to detect lpg tuberculosis mycobacterium DNA. The probe test showed that, among 21 oligonucleotide probes, probe-M. fortuitum and M. marinum were cross-hybrid; the other probes were specific. We used the new method to identify 126 mycobacterium clinical isolated specimens. The test results of this new method matched with conventional method. In conclusion, compared to the traditional method, the use of rpob gene chip technology to identify mycobacterium species will be faster, more accurate and higher value in application.

关键词： mycobacterium rpoB gene chip technology oligonucleotide probes

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优化的五阶段蓄电池充电方法研究

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电源技术 2012年第10期36卷 1496-1499页

作者：王玮茹张建成华北电力大学电力工程系河北保定071003

阀控式密封铅酸蓄电池(VRLA)广泛应用于光伏发电系统中,为延长其使用寿命、降低光伏电能成本,同时提高光伏发电系统运行性能,对铅酸蓄电池的充电特性进行了分析,提出一种阶段恒流与脉冲充电相结合的五段式充电方法,这种方法能加快充电... 详细信息

阀控式密封铅酸蓄电池(VRLA)广泛应用于光伏发电系统中,为延长其使用寿命、降低光伏电能成本,同时提高光伏发电系统运行性能,对铅酸蓄电池的充电特性进行了分析,提出一种阶段恒流与脉冲充电相结合的五段式充电方法,这种方法能加快充电速度并有效延长蓄电池的使用寿命。对VRLA充电方法进行了仿真分析,结果表明该方法能够最大限度地提高蓄电池充电效率,从而提高了光伏系统的工作效率,实现系统的优化运行。由于该方法充分考虑了蓄电池内部电化学反应特性,可以消除极板极化现象,所以蓄电池的使用寿命可以延长。

关键词：阀控式密封铅酸蓄电池涓流充电脉冲充电极化

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CaCl_2-BaCl_2-NH_3二级吸附式制冷系统及其制冷性能与仿真

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上海交通大学学报 2011年第9期45卷 1389-1394页

作者：王健胡远扬王丽伟王如竹上海交通大学制冷与低温工程研究所上海200240

在低于100°C热源、高于30°C冷凝温度的条件下,为了获得-15°C的冷冻工况,采用二级解吸过程设计了氯化钙/氯化钡吸附氨的吸附制冷系统,并对氯化钙/氯化钡工质对的吸附性能参数进行测试,由其性能数据拟合而得到吸附与解吸曲线、耦合吸... 详细信息

在低于100°C热源、高于30°C冷凝温度的条件下,为了获得-15°C的冷冻工况,采用二级解吸过程设计了氯化钙/氯化钡吸附氨的吸附制冷系统,并对氯化钙/氯化钡工质对的吸附性能参数进行测试,由其性能数据拟合而得到吸附与解吸曲线、耦合吸附与解吸方程和传热方程,并建立系统模型进行仿真.结果表明,该系统可以利用85°C的低温热源,在30°C的冷凝温度条件下获得-15°C的制冷温度,并达到2.62 kW的制冷功率.

关键词：氯化钙氯化钡二级吸附式制冷低温热源仿真

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Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie wang wei wang Xuheng Chen Junfang Bao Qiuyue Hao Heng Zheng runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

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Crystallization behavior of PEG side chain on Comb-like Poly（acrylic acid）-g-Poly（ethylene glycol） Copolymers

Crystallization behavior of PEG side chain on Comb-like Poly...

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2004年全国高分子材料科学与工程研讨会

作者： Liu Zhan, wang wei-ru, Gao Yan-fang, Xie Xu-ming (Department of Chemical Engineering, Tsinghua University, Beijing 100084)

＜正＞ The Crystallization behavior of PEG side chain（Mw=1100,5000 g/mol）in Comb-likePoly（acrylic acid）-g-Poly（ethylene glycol）Copolymers were analyzed by *** resultsindicate the melting characteristics and crystallization behaviors of the mPEG side-chain incopolymer bulks were drastically different from homo-polymer bulks of the ***,the crystal morphologies of the comb-like copolymers in thin films prepared by means of spin-coating on glass substrates were observed by phase contrast *** is noticeable that a lotof specially interesting branched crystal morphologies were formed through DLA processes.

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基于模糊自适应PI控制的光伏发电MPPT

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电网与清洁能源 2011年第6期27卷 61-64页

作者：王玮茹华北电力大学电力系统保护与动态安全监控教育部重点实验室河北保定071003

介绍了光伏发电过程中最大功率点跟踪(MPPT)原理,并简要分析了常规控制算法在最大功率跟踪控制中的优缺点,提出将模糊自适应PI控制算法应用到光伏系统最大功率点跟踪的控制中,该控制方法能快速响应外界环境的变化,获得系统最大功率点,... 详细信息

介绍了光伏发电过程中最大功率点跟踪(MPPT)原理,并简要分析了常规控制算法在最大功率跟踪控制中的优缺点,提出将模糊自适应PI控制算法应用到光伏系统最大功率点跟踪的控制中,该控制方法能快速响应外界环境的变化,获得系统最大功率点,且可以有效消除系统在最大功率点附近的振荡现象,提高系统的稳定性。仿真结果表明,该方法能使系统稳定地工作在最大功率点,并且控制精度高,能灵敏反应外界环境的变化。

关键词：光伏系统最大功率点跟踪fMPP田模糊自适应PI控制

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2011年济南市其他感染性腹泻病监测资料分析

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现代预防医学 2015年第3期42卷 542-544页

作者：许华茹王蔚茹常彩云济南市疾病预防控制中心

目的了解2011年济南市其他感染性腹泻的流行特点,为更好开展感染性腹泻监测工作提供数据支持。方法收集2011年济南市其他感染性腹泻的疫情报告资料和专项监测资料,进行描述性统计分析。结果 2011年济南市其他感染性腹泻病发病率为17.82... 详细信息

目的了解2011年济南市其他感染性腹泻的流行特点,为更好开展感染性腹泻监测工作提供数据支持。方法收集2011年济南市其他感染性腹泻的疫情报告资料和专项监测资料,进行描述性统计分析。结果 2011年济南市其他感染性腹泻病发病率为17.82/10万,较2010年(11.95/10万)上升49.10%;郊县报告发病明显高于城区(χ2=12.10,P<0.005),发病有夏季和秋冬两个高峰;男性发病多于女性,5岁以下年龄组发病占54.86%,散居儿童发病占53.13%。专项监测结果显示我市腹泻病人群腹泻病毒阳性率为39.58%,其中轮状病毒阳性率为28.13%,诺如病毒阳性率为13.54%,混合感染率为2.08%。结论 5岁以下的散居儿童是济南市其他感染性腹泻的重点人群,病毒性腹泻在秋冬季腹泻中占有相当比例,应加强对其他感染性腹泻病的监测工作。

关键词：感染性腹泻病监测轮状病毒诺如病毒

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