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WALL PRESSURE FLUCTUATIONS OF TURBULENT FLOW OVER BACKWARD-FACING STEP WITH AND WITHOUT ENTRAINMENT: MICROPHONE ARRAY MEASUREMENT

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Journal of Hydrodynamics 2006年第4期18卷 393-396页

作者： KE Feng LIU ying-zheng wang Wei-zhe CHEN Han-ping School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

Wall pressure fluctuations in turbulent boundary layer flow over backward-facing step with and without entrainment were investigated. Digital array pressure sensors and multi-arrayed microphones were employed to acquire the time-averaged static pressure and fluctuating pressure, respectively. The differences of two flows were scrutinized in terms of static pressure characteristics, pressure fluctuations, cross-correlation and coherence of wall pressure. Introduction of the entrainment increased scale of large-scale vortical structure and reduced its convection velocity. However, shedding frequency of large-scale vortical structures was found to be the same for both flows.

关键词： backward-facing step turbulent boundary layer entrainment wall pressure fluctuations Microphone Array

Plasma thrombomodulin changes in acute cerebral infarction or hypertension patients An observation for verification

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Neural Regeneration Research 2008年第1期3卷 71-74页

作者： Pu Feng Hui Zhang Bingyi Yang Yonggang zheng Jinhui Xie ying wang Jinchuan Li Department of Internal Medicine Yuquan Hospital of Tsinghua University （Second Affiliated Hospital of Tsinghua University） Beijing100049 China

BACKGROUND： Thrombomodulin concentration greatly increases in plasma when vascular endothelial cells are injured, and it is one of the specific molecular markers for endothelial injury. OBJECTIVE： To analyze the plasma levels of thrombomodulin after cerebral infarction or hypertension, and to compare levels with those from healthy control subjects. DESIGN： A case-controlled observation. SETTING： Yuquan Hospital of Tsinghua University. PARTICIPANTS： Patients with hypertension （n = 37） and acute cerebral infarction （n = 26） were selected from the outpatient and inpatient Department of Neurology, Yuquan Hospital of Tsinghua University from February 2003 to February 2006. The cerebral infarction group consisted of 24 males and 2 females, 36-77 years of age, with a mean age of 62 years. All patients fulfilled the diagnosis criteria for cerebral infarction, according to the diagnostic standards revised by the Second National Academic Meeting for Cerebrovascular Disease, and were confirmed by CT or MRI. The hypertension group consisted of 27 males and 10 females, 36-77 years of age, with a mean age of 56 years. These patients fulfilled the diagnostic criteria for hypertension set by WHO. In addition, 43 healthy physical examinees were selected as the control group, consisting of 23 males and 20 females, 35-67 years of age. Informed consent was obtained from all participants. METHODS： In the cerebral infarction group, thrombomodulin plasma levels were determined by enzyme-linked immunoabsorbent assay at days 1, 3, 7, and 14 after attack. Thrombomodulin plasma levels were determined only once in the hypertension group and the control group. The results from the cerebral infarction group were compared with those from the hypertension group and the control group. MAIN OUTCOME MEASURES： Level of thrombomodulin in plasma. RESULTS： All 63 patients and 43 healthy volunteers were included in the final analysis of results. （1） At 7 days after the attack, the plasma levels of thrombo

关键词： thrombomudulin cerebral infarction MRI

Development of Fixture Layout Optimization for Thin-Walled Parts:A Review

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 15-39页

作者： Changhui Liu Jing wang Binghai Zhou Jianbo Yu ying zheng Jianfeng Liu School of Mechanical Engineering Tongji UniversityShanghai 201804China Shanghai Jiaotong University Shanghai 200240China Shanghai Waigaoqiao Shipbuilding Co. Ltd.Shanghai 200137China

An increasing number of researchers have researched fixture layout optimization for thin-walled part assembly during the past ***,few papers systematically review these *** analyzing existing literature,this paper summarizes the process of fixture layout optimization and the methods *** process of optimization is made up of optimization objective setting,assembly variation/deformation modeling,and fixture layout *** paper makes a review of the fixture layout for thin-walled parts according to these three ***,two different kinds of optimization objectives are *** usually consider in-plane variations or out-of-plane deformations when designing ***,modeling methods for assembly variation and deformation are divided into two categories:Mechanism-based and data-based *** common methods are discussed *** that,optimization algorithms are reviewed *** are two kinds of optimization algorithms:Traditional nonlinear programming and heuristic ***,discussions on the current situation are *** research direction of fixture layout optimization in the future is discussed from three aspects:Objective setting,improving modeling accuracy and optimization ***,a new research point for fixture layout optimization is *** paper systematically reviews the research on fixture layout optimization for thin-walled parts,and provides a reference for future research in this field.

关键词： Thin-walled parts Assembly quality Fixture layout optimization Modeling methods Optimization algorithms

Optimization of Fixture Number in Large Thin-Walled Parts Assembly Based on IPSO

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 213-227页

作者： Changhui Liu Jing wang ying zheng Ke Jin Jianbo Yu Jianfeng Liu School of Mechanical Engineering Tongji UniversityShanghai 201804China Shanghai Jiaotong University Shanghai 200240China Shanghai Waigaoqiao Shipbuilding Co. Ltd.Shanghai 200137China

There are lots of researches on fixture layout optimization for large thin-walled *** researches focus on the positioning problem,i.e.,optimizing the positions of a constant number of ***,how to determine the number of fixtures is *** most cases,the number of fixtures located on large thin-walled parts is determined based on engineering experience,which leads to huge fixture number and extra ***,this paper constructs an optimization model to minimize the number of *** constraints are set in the optimization model to ensure that the part deformation is within the surface profile *** addition,the assembly gap between two parts is also *** conduct the optimization,this paper develops an improved particle swarm optimization(IPSO)algorithm by integrating the shrinkage factor and adaptive inertia *** the algorithm,particles are encoded according to the fixture *** dimension of the particle is assigned to a sub-region by constraining the optional position range of each fixture to improve the optimization ***,a case study on ship curved panel assembly is provided to prove that our method can optimize the number of fixtures while meeting the assembly quality *** research proposes a method to optimize the number of fixtures,which can reduce the number of fixtures and achieve deformation control at the same time.

关键词： Assembly quality Large thin-walled parts Fixture layout PSO FEM

Non-intrusive Load Monitoring Based on Graph Total Variation for Residential Appliances

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 947-957页

作者： Xiaoyang Ma Diwen zheng Xiaoyong Deng ying wang Dawei Deng Wei Li the College of Electrical Engineering Sichuan UniversityChengdu 610065China State Grid Chongqing Electric Power Company Chongqing 400014China State Grid Sichuan Electric Power Company Chengdu 610095China State Grid Hubei Electric Power Company Limited Research Institute Wuhan 430077China

Non-intrusive load monitoring is a technique for monitoring the operating conditions of electrical appliances by collecting the aggregated electrical information at the household power *** several studies on the mining of unique load characteristics,few studies have extensively considered the high computational burden and sample *** on lowfrequency sampling data,a non-intrusive load monitoring algorithm utilizing the graph total variation(GTV)is proposed in this *** algorithm can effectively depict the load state without the need for prior ***,the combined Kmeans clustering algorithm and graph signals are used to build concise and accurate graph structures as load *** GTV representing the internal structure of the graph signal is introduced as the optimization model and solved using the augmented Lagrangian iterative *** introduction of the difference operator reduces the computing cost and addresses the inaccurate reconstruction of the graph *** low-frequency sampling data,the algorithm only requires a little prior data and no training,thereby reducing the computing *** conducted using the reference energy disaggregation dataset and almanac of minutely power dataset demonstrated the stable superiority of the algorithm and its low computational burden.

关键词： Non-intrusive load monitoring graph total variation augmented Lagrangian function smart grid

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

Afterglow Nanoprobes for In-vitro Background-free Biomarker Analysis

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Chemical Research in Chinese Universities 2024年第2期40卷 213-224页

作者： zheng Ting wang ying LI Xianming LI Chenghui WU Peng Analytical&Testing Centre State Key Laboratory of Hydraulics and Mountain River EngineeringSichuan UniversityChengdu610064P.R.China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang453007P.R.China Department of Rheumatology and Immunology West China HospitalSichuan UniversityChengdu610064P.R.China

Accurate detection of biomarkers is essential for disease *** the highly sensitive fluorescence probes are feasible for the above goal,it is typically interfered by the auto-fluorescence and light scattering of the biological *** afterglow system(consisting of photosensitizer,afterglow substrate and emitter)based on cascade photochemical reactions exhibits long-lived luminescence(seconds to hours),thus avoiding background *** the assistance of polymers,such as polystyrene microspheres,the photochemical afterglow systems have been transformed into homogeneous and water-soluble nanoparticles,and used for in-vitro biomarker ***,we summarized the principle,preparation and applications of these afterglow nanoparticles,and evaluated their performance in clinical sample testing by comparing with other nanoparticle-based ***,several problems and possible solutions of afterglow nanoparticle-based methods in biomarker determination were also mentioned.

关键词： Photochemical afterglow In-vitro analysis Background-free detection Biomarker

Understanding Urban Vitality from the Economic and Human Activities Perspective:A Case Study of Chongqing,China

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维普期刊数据库

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Chinese Geographical Science 2024年第1期34卷 52-66页

作者： YANG Fiona Fan LIN Geng LEI Yubing wang ying YI zheng School of Geography and Planning Sun Yat-sen UniversityGuangzhou510006China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519100China Chongqing Planning and Design Institute Chongqing401147China

The literature on urban vitality tends to focus on the built *** paper argues that some important processes in shaping vitality may be overlooked without examining the intensity and diversity of economic and human *** newly developed spatial big data and adopting the methods of multi-indicator measurement and spatial analysis methods,we analyzed the pattern of urban vitality in Chongqing,a provincial city in western China and,on this basis,evaluated the creation and maintenance of urban vitality from the economic and human activities *** findings indicate that the impacts of economic and human activities are positive and *** the three intensity and diversity indicators,economic intensity and population density show an effect on urban vitality stronger than that of economic ***,economic diversity has the strongest superposition or interactive effect,and is thus an important foundation *** positive effect of population density on urban vitality is largely a result of Chongqing’s jobs-housing *** case of Chongqing highlights the importance of topographic features,historical inheritance,large-scale migration,and cultural activities in shaping the distinctive vitality pattern of a *** study contends that the creation and maintenance of urban vitality can not be fully explained without incorporating the impacts of economic and human *** contributes to a comprehensive measurement of urban vitality and enriches its connotations.

关键词： urban vitality economic diversity economic intensity population density Chongqing,China

Sustainable ammonia synthesis:An in-depth review of non-thermal plasma technologies

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Journal of Energy Chemistry 2024年第9期96卷 1-38页

作者： Vahid Shahed Gharahshiran ying zheng Department of Chemical and Biochemical Engineering Thompson Engineering BuildingWestern UniversityLondonON N6A 5B9Canada

Ammonia serves both as a widely used fertilizer and environmentally friendly energy source due to its high energy density,rich hydrogen content,and emissions-free ***,it offers convenient transportation and storage as a hydrogen *** dominant method used for large-scale ammonia production is the Haber-Bosch process,which requires high temperatures and pressures and is ***,non-thermal plasma offers an eco-friendly alternative for ammonia synthesis,gaining significant *** enables ammonia production at lower temperatures and pressures using plasma *** review provides insights into the catalyst and reactor developments,which are pivotal for promoting ammonia efficiency and addressing existing *** first,the reaction kinetics and mechanisms are introduced to gain a comprehensive understanding of the reaction pathways involved in plasma-assisted ammonia ***,the enhancement of ammonia synthesis efficiency is discussed by developing and optimizing plasma reactors and effective *** effect of other feeding sources,such as water and methane,instead of hydrogen is also ***,the challenges and possible solutions are outlined to facilitate energy-saving and enhance ammonia efficiency in the future.

关键词： Nitrogen fixation Ammonia synthesis NH_(3) Non-thermal plasma Ni Ru catalyst