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墩头角度对竖缝式鱼道水力特性的影响

长江科学院院报 2024年第6期41卷 84-90,97页

作者：韩雷吕春玮王正君张帅康李洋黑龙江省水利科学研究院水力学研究所哈尔滨150080 黑龙江大学水利电力学院哈尔滨150080

竖缝式鱼道隔板、导板的墩头角度是影响其池室水流结构的因素之一。采用数值模拟方法,依据RNGk-ε方程,主要通过改变隔板与导板墩头在迎水面与背水面角度的方式,来研究竖缝式鱼道的水力特性。在不同墩头角度情况下,通过对比相应鱼道池... 详细信息

竖缝式鱼道隔板、导板的墩头角度是影响其池室水流结构的因素之一。采用数值模拟方法,依据RNGk-ε方程,主要通过改变隔板与导板墩头在迎水面与背水面角度的方式,来研究竖缝式鱼道的水力特性。在不同墩头角度情况下,通过对比相应鱼道池室内的水流流态、流速、紊动能等数据,获得较为适宜的鱼道隔板设计型式。试验结果表明:隔板和导板迎水面墩头角度逐渐增大时,均会导致池室主流逐渐靠近池室一侧边壁;在主流未受到池室边壁的影响时,水流流速整体呈下降趋势;导板迎水面墩头角度变化对池室水流结构影响更大。研究成果可为鱼道优化设计提供数据支撑。

关键词：竖缝式鱼道水力特性隔板导板墩头角度数值模拟鱼道设计

Fouling and cleaning of membrane——a literature review

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Journal of Environmental Sciences 2000年第2期12卷 116-126页

作者： Zhao, Yan-jun Wu, Kai-Fen wang, zheng-jun Zhao, Liang Li, Shu-Shen Polymer Membrane Division Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Membrane fouling curtails severely the economical and practical implementation of membrane process. The fundamental principles and mechanisms of membrane fouling as well as factors affecting fouling have been summarized in this paper. It also has covered three fouling resistance models and four kinds of approaches to improve membrane performance. Membrane cleaning methods are also discussed including physical, chemical, physico\|chemical and biological methods. In the four groups of basic cleaning methods, biological cleaning has considerable advantages and potentials. Extensive research work should be carried out further to explore and develop new ideas and techniques in the field of membrane cleaning and restoration.

关键词： membrane fouling cleaning CLC number: X703 Document code: A

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大流量倒虹吸水力特性研究

水电能源科学 2024年第8期42卷 114-118页

作者：张帅康韩雷叶昆河赵兴龙李洋王正君黑龙江大学水利电力学院黑龙江哈尔滨150080 黑龙江省水利科学研究院黑龙江哈尔滨100050

为保证大流量倒虹吸能够安全稳定的输水,采用流体动力学软件(CFD)对某工程三维数学模型进行数值模拟,并结合物理模型试验,分析了倒虹吸充水过程中水流变化特点和稳定后的水力特性。结果表明,倒虹吸水流流速最大位置位于管道下坡段,压强... 详细信息

为保证大流量倒虹吸能够安全稳定的输水,采用流体动力学软件(CFD)对某工程三维数学模型进行数值模拟,并结合物理模型试验,分析了倒虹吸充水过程中水流变化特点和稳定后的水力特性。结果表明,倒虹吸水流流速最大位置位于管道下坡段,压强最大位置位于管道水平段;充水过程中,倒虹吸边部管道内水流流速较中部水流大8%左右;在水流稳定后倒虹吸下游闸室后存在卡门涡街现象,造成水流流态紊乱,导致下游水面震荡,需要对下游闸墩进行延长或进行墩头结构优化,以减轻涡街强度和水面震荡的影响。

关键词：倒虹吸水力特性数值模拟充水过程卡门涡街

Achieving tunable long persistent luminescence in metal organic halides based on pyridine solvent

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Chinese Chemical Letters 2024年第9期35卷 227-231页

作者： jun-Ting Mo zheng wang College of Chemistry and Chemical Engineering Key Laboratory of Chemical Additives for China National Light IndustryShaanxi University of Science and TechnologyXi’an 710021China MOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional MaterialsSchool of ChemistrySun Yat-sen UniversityGuangzhou 510275China

The research of long persistent luminescence(LPL)materials has yield brilliant results in many ***,the efforts are still needed for the regulation of the LPL *** this work,a series of LPL metal organic halides with rich halogen-bond interactions,Py-CdX_(2)(X=Cl,Br,I)were synthesized through self-assembly by Cd X_(2)and pyridine *** steady-state emission redshifted and phosphorescence lifetime declined as the halogen atoms are *** halides exhibit adjustable emission from blue to green and multiple phosphorescence from green to yellow at room temperature by changing the excitation ***,Py-CdX_(2)can emit the visible color-tunable LPL from green to yellow after removing different excitation sources at ambient *** the results of theoretical calculation and experimental analysis,it is found that heavy atom effect and the rich intermolecular halogen bond help realize LPL and multiple triplet states originated from the pyridine ring and the halogens.

关键词： Metal organic halide Heavy atom effect Halogen bond Tunable long persistent luminescence Anti-counterfeiting

Small-signal Stability Constrained Optimal Power Flow Considering Eigenvalue Distribution

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1052-1062页

作者： zheng Huang Kewen wang Yi wang Jing Han jun Liang the School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001China Cardiff University Cardiff CF243AAU.K.

In the existing small-signal stability constrained op-timal power flow(SSSC-OPF)algorithms,only the rightmost ei-genvalue or eigenvalues that do not satisfy a given threshold,e.g.,damping ratio threshold and real-part threshold of eigen-value,are considered in the small-signal stability *** effect of steady-state,i.e.,operating point,changes on eigen-values is not fully taken into *** this paper,the small-signal stability constraint that can fully reflect the eigenvalue change and system dynamic performance requirement is formed by analyzing the eigenvalue distribution on the complex *** small-signal stability constraint is embedded into the standard optimal power flow model for generation *** simultaneous solution formula of the SSSC-OPF is es-tablished and solved by the quasi-Newton approach,while pen-alty factors corresponding to the eigenvalue constraints are de-termined by the stabilization degree of constrained *** improve the computation speed,a hybrid algorithm for ei-genvalue computation in the optimization process is proposed,which includes variable selection for eigenvalue estimation and strategy selection for eigenvalue *** effectiveness of the proposed algorithm is tested and validated on the New England 10-machine 39-bus system and a modified practical 68-machine 2395-bus system.

关键词： Damping ratio eigenvalue optimal power flow quasi-Newton approach sensitivity small-signal stability

县级农产品质量安全检测机构“双认证”工作探讨

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中国检验检测 2024年第3期32卷 69-71,74页

作者：李兴王正军刘建雄刘胜湘潭县产品商品检验检测中心湘潭411229 安化县市场监督管理局安化413599

根据《检验检测机构资质认定评审准则》《农产品质量安全法》《农产品质量安全检测机构考核办法》,农产品质量安全检测机构对外开展农产品质量安全检测的前提是获得资质认定和机构考核,即“双认证”。本文结合湘潭县产品商品检验检测中... 详细信息

根据《检验检测机构资质认定评审准则》《农产品质量安全法》《农产品质量安全检测机构考核办法》,农产品质量安全检测机构对外开展农产品质量安全检测的前提是获得资质认定和机构考核,即“双认证”。本文结合湘潭县产品商品检验检测中心首次通过“双认证”考核的案例,从人、机、料、法、环等方面总结了县级农产品质量安全检测机构如何顺利通过“双认证”的经验做法,为县级检验检测机构认证和管理提供技术参考。

关键词：县级检验检测机构农产品质量安全资质认定机构考核

Joint space compliance control for a hydraulic quadruped robot based on force feedback

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Journal of Beijing Institute of Technology 2016年第3期25卷 337-345页

作者： wang jun-zheng KE Xian-feng wang Shou-kun HE Yu-dong Key Laboratory of Intelligent Control and Decision of Complex System School of Automation Beijing Institute of Technology Beijing 100081 China

In the realm of quadruped robot locomotion,compliance control is imperative to handle impacts when negotiating unstructured *** the same time,kinematic tracking accuracy should be guaranteed during *** meet both demands,ajoint space compliance controller is designed,so that compliance can be achieved in stance phase while position tracking performance can be guaranteed in swing *** operational space compliance control,the joint space compliance control method is easy to implement and does not depend on robot *** for each joint actuator,high performance force control is of great importance for compliance ***,a nonlinear PI controller based on feedback linearization is proposed for the hydraulic actuator force ***,an outer position loop（compliance loop）is closed for each *** are carried out to verify the force controller and compliance of the hydraulic *** robot leg compliance is assessed by a virtual prototyping simulation.

关键词： hydraulic quadruped robot impact stiffness joint space compliance control nonlinear controller

A Method for Evaluating the Maximum Bending Degree of Flexural Toppling Rock Masses Based on the Rock Tensile Strain-Softening Model

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Journal of Earth Science 2024年第4期35卷 1243-1253页

作者： Jiongchao wang jun zheng Jichao Guo Qing Lü Jianhui Deng Department of Civil Engineering Zhejiang UniversityHangzhou310058China Center for Balance Architecture Zhejiang UniversityHangzhou310007China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

Flexural toppling occurs when a series of layered rock masses bend towards their free *** is important to evaluate the maximum bending degree and the requirement of supports of flexural toppling rock mass to prevent rock mass cracking and even failure leading to a *** on the rock tensile strain-softening model,this study proposes a method for calculating the maximum curvature(C_(ppmax))of flexural toppling rock *** applying this method to calculate Cppmax of 9 types of rock masses with different hardness and rock layer thickness,some conclusions are drawn:(1)the internal key factors affecting C_(ppmax)are E^(⋆)(E^(⋆)=E_(ss)/E_(0),where E_(0)and E_(ss)are the mean deformation moduli of the rock before and after reaching its peak tensile strength,respectively),the strainεt corresponding to the tensile strength of rock,and the thickness(h)of rock layers;(2)hard rock layers are more likely to develop into block toppling than soft rock layers;and(3)thin rock layers are more likely to remain in flexural toppling state than thick rock *** addition,it is found that C_(ppmax)for flexural toppling rock masses composed of bedded rocks such as gneiss is related to the tensile direction.

关键词： flexural toppling rock mass maximum bending degree strain-softening model curvature rock mechanics

Recent advances in heterogeneous catalysis of solar-driven carbon dioxide conversion

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Journal of Environmental Sciences 2024年第6期140卷 165-182页

作者： jun Xu Farzaneh Arabpour Roghabadi Ying Luo Vahid Ahmadi Qian wang zheng wang Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Chemistry and Chemical Engineering Henan Polytechnic UniversityJiaozuoHenan 454000China Department of Process Engineering Faculty of Chemical EngineeringTarbiat Modares UniversityTehranIran Optoelectronics and Nanophotonics Research Group Faculty of Electrical and Computer EngineeringTarbiat Modares UniversityTehranIran Graduate School of Engineering Nagoya UniversityFuro-choChikusa-kuNagoya 464-8603Japan

Solar-driven carbon dioxide(CO_(2))conversion including photocatalytic(PC),photoelectrochemical(PEC),photovoltaic plus electrochemical(PV/EC)systems,offers a renewable and scalable way to produce fuels and high-value chemicals for environment and energy *** review summarizes the basic fundament and the recent advances in the field of solar-driven CO_(2)*** the visible-light absorption is an important strategy to improve solar energy conversion *** separation and migration of photogenerated charges carriers to surface sites and the surface catalytic processes also determine the photocatalytic *** engineering including co-catalyst loading,defect engineering,morphology control,surface modification,surface phase junction,and Z-scheme photocatalytic system construction,have become fundamental strategies to obtain high-efficiency *** to photocatalysis,these strategies have been applied to improve the conversion efficiency and Faradaic efficiency of typical PEC *** PV/EC systems,the electrode surface structure and morphology,electrolyte effects,and mass transport conditions affect the activity and selectivity of electrochemical CO_(2)***,the challenges and prospects are addressed for the development of solar-driven CO_(2)conversion system with high energy conversion efficiency,high product selectivity and stability.

关键词： Solar-driven CO_(2)reduction Photocatalytic system Photoelectrochemical system Photovoltaic plus electrochemical system Surface/interface engineering