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One-dimensional/three-dimensional analysis of transient cavitating flow in a venturi tube with special emphasis on cavitation excited pressure fluctuation prediction

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Science China(Technological Sciences) 2020年第2期63卷 223-233页

作者： wang luyan JI Bin CHENG HuaiYu wang Jiong LONG XinPing Key Laboratory of Hydraulic Machinery Transients Ministry of EducationWuhan UniversityWuhan 430072China Key Laboratory of Hubei Province for Waterjet Theory and New Technology Wuhan 430072China School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China

The large eddy simulation(LES) method is used to simulate cavitating flow in a venturi tube. The simulated results agree fairly well with the experimental data. To quantitatively describe the relationship between cavitation evolution and excited pressure fluctuation in the venturi tube, a modified prediction model is proposed and its accuracy is verified by the LES results. Based on the original one-dimensional model for the external cavitating flow around a hydrofoil, this model is corrected according to the internal cavitating flow characteristics in the venturi tube. The results show that the original one-dimensional model ignores the choking effect of cavitating flow, which is obvious in a venturi tube with a narrow flow channel, thus leading to an inaccurate prediction of pressure fluctuation in the venturi tube. The modified model can significantly overcome its deficiencies and improve the accuracy of the pressure fluctuation prediction, providing a theoretical basis and guidance for engineering application to controlling the pressure fluctuation in a venturi tube or for other internal flows.

关键词： venturi tube LES modified model cavitation pressure fluctuation

Surface chemical structure of titania-silica nanocomposite powder

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Chinese Science Bulletin 2008年第19期53卷 2964-2972页

作者： wang luyan SUN YanPingi XU BingShe Chemical Engineering Department Taiyuan University of Technology Taiyuan 030024 China Key Laboratory of Interface and Engineering in Advanced Materials of Ministry of Education of China Taiyuan University of Technology Taiyuan 030024 China

Titania-silica (TS) nanocomposite powder with three different composite structures, containing 10―30 mol% SiO2 in each structure, have been prepared by sol-gel processes. The surface characteristics of these titania-silica samples have been investigated by X-ray photo-emission spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM). The study for all TS oxides annealed at 773 and 1173 K showed: an abnormal surface enrichment in Si increased with increasing annealing temperature; the Ti3+, Ti2+, Si3+ and Si2+ oxides coexisted with Ti4+ and Si4+ oxides, and the contents of these Ti/Si suboxides increased with increasing SiO2 content and annealing temperature; there was a layer rich in O on the topmost surface and the excess O could be attributed to the chemadsorption of H2O; different composite structures could lead to different contents of Ti/Si suboxides. These results indi- cated that the surface of TS oxide powder derived by sol-gel process was a double layer with enriched O first and then SiOx/TiOy (x, y<2). Ti/Si suboxides could result from the thermal diffusion of Ti4+ and Si4+, which might be induced by the strong interaction between Ti4+ and Si4+.

关键词：表面结构三氧化钛硅石低值氧化物

Practice and Research Progress on Ecosystem Conservation in Transboundary Areas

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Chinese Geographical Science 2016年第1期26卷 109-116页

作者： TANG Lina GUI Liuming SHAO Guofan wang luyan SHI Longyu Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of Sciences Department of Forestry and Natural Resources Purdue University

Many ecosystems extend across national or political boundaries. The consistent and effective protection of these ecosystems in transboundary areas(ETAs) is an important global research focus. Previous research on the protection of such areas can be categorized into seven themes: 1) ecological conservation of a single ETA; 2) investigation of the effects of a single conservation measure on a specific ETA; 3) determination of species-level effects due to ETA conservation; 4) comparison of the same protection measures between different ETAs; 5) introduction of a single conservation measure to a specific ETA; 6) understanding the relationship between conservation and sustainable development; and 7) generalization across multiple ETA conservation cases. The protection of ETAs involves various considerations, including funding support, demand and will for collaboration, community and public participation, historical and cultural factors, political backgrounds, uniqueness of biological resources, formulation of laws and regulations, founding of specialized administrative departments, non-governmental organizations, and fairness. Here, we briefly explain the research themes and considerations related to ETA conservation. The most important finding is that most major research themes do not focus on the challenges of ETA conservation. We use two nature reserves located between China and North Korea as examples to identify specific ways to improve ETA conservation on Changbai Mountains. The efficiency of ETA administration still remains low. The study of ETA conservation should focus on concrete regional information and aim to improve existing measures through the accumulation of experience.

关键词： ecosystem in transboundary area (ETA) intemational cooperation transboundary cooperation regional sustainable development terrestrial ecosystem

Facile Synthesis of Multi-Branched Gold Nanostructures through a TBAB-Assisted Route in Aqueous Solution and Their SERS Property

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Chinese Journal of Chemistry 2011年第1期29卷 185-190页

作者： wang, luyan Wu, Xinzhou Pei, Meishan Wu, Zhiyan Li, Xiaonan Tao, Xutang School of Chemistry and Chemical Engineering University ofJinan Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials Jinan Shandong 250022 China State Key Laboratory of Crystal Materials (Shandong University) Jinan Shandong 250100 China

Facile synthesis of multi-branched gold nanostructures by using the tetrabutyl ammonium bromide （TBAB） as a capping agent is described. The reaction is carried out in a one-step process at mild temperature. Gold nanostructures with more than six sharp branches ranging from 70 to 130 nm in length are synthesized in high yield. It is proposed that the relative weak adsorption capacity of TBAB leads to the incompletely covered gold surface and the growth of nanoparticles occurs on the uncovered gold surface, and therefore short branches appear consequently. Then positively charged TBAB layers on the gold surfaces prevent the branches from aggregating with each other which stimulates the branch growth. The prepared branched gold nanoparticles show efficient surface-enhanced Raman scattering （SERS） properties. Low temperature （4 ℃） is unfavorable to the formation of multi-branched gold nanostructures, and only thin small irregular plate-like nanoparticles are produced. The addition of SDS in TBAB aqueous solution results in forming SDS micelles at much lower concentration of SDS （0.4 mmol/L） as compared to that in pure water, and short branched gold nanoparticles are obtained in the SDS-TBAB system.

关键词： gold multi-branched nanostructures tetrabutyl ammonium bromide surface-enhanced Ramanscattering

A facile approach for synthesis of high-stable CdS nanoparticles

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Chinese Science Bulletin 2006年第10期51卷 1266-1268页

作者： LI Cheng CHEN Xiao SUI Zhenming wang luyan XU Limei HAO Jingcheng Key Laboratory of Colloid and Interface Chemistry of Education Ministry Shandong University Jinan 250100 China

CdS nanoparticles with prolonged sta- bility against photo-oxidation have been successfully synthesized in aqueous solution using 2-mercapto- succinic acid (MSA) as stabilizer at room temperature The growth progress of particles is found to be af- fected with changing Cd2+ concentration. Whether the thiol group in MSA could be dissociated plays an important role on the effective passivation of CdS nanoparticles.

关键词：硫化镉纳米粒子合成稳定性丁二酸半导体

Thermal Runaway Characteristics and Modeling of LiFePO4 Power Battery for Electric Vehicles

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Automotive Innovation 2023年第3期6卷 414-424页

作者： Tao Sun luyan wang Dongsheng Ren Zhihe Shi Jie Chen Yuejiu Zheng Xuning Feng Xuebing Han Languang Lu Li wang Xiangming He Minggao Ouyang School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China

LiFePO_(4)(LFP)lithium-ion batteries have gained widespread use in electric vehicles due to their safety and longevity,but thermal runaway(TR)incidents still have been *** paper explores the TR characteristics and modeling of LFP batteries at different states of charge(SOC).Adiabatic tests reveal that TR severity increases with SOC,and five stages are identified based on battery temperature *** kinetics parameters of exothermic reactions in each TR stage are extracted,and TR models for LFP batteries are *** models accurately simulate TR behaviors at different SOCs,and the simulated TR characteristic temperatures also agree well with the experimental results,with errors of TR characteristic temperatures less than 3%.The prediction errors of TR characteristic temperatures under oven test conditions are also less than 1%.The results provide a comprehensive understanding of TR in LFP batteries,which is useful for battery safety design and optimization.

关键词： Lithium-ion battery Safety Thermal runaway Thermal runaway model State of charge

Application of Classical Garden Cultural Aesthetics in Landscape Planning and Design:A Case Study of Huaqing Palace in Xi'an City of China

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Journal of Landscape Research 2012年第11期4卷 51-53页

作者： ZHANG Ying wang luyan LIU Hui College of Art Xi'an University of Architecture and Technology College of Architecture Xi'an University of Architecture and Technology

Taking Huaqing Palace in Xi'an City for example,landscape architectural features of Huaqing Palace,its classical garden cultural heritage and aesthetic consciousness of landscape culture were *** was proposed that its rich cultural characteristics and aesthetic elements should be fully used,modern landscape planning theories and design techniques applied to integrate into the designs,satisfy requirements of modern people's life,fully demonstrate history,culture and aesthetic characteristics of the scenic area,and also support its future construction.

关键词： Huaqing Palace Landscape Aesthetics

上海徐汇区“蓝色网络”系统规划与更新行动思考

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规划师 2021年第S1期37卷 82-87页

作者：王璐妍华建集团华东建筑设计研究院有限公司规划建筑设计院国土空间规划所

上海的城市建设已经进入一个以精细化、内涵式发展为特征的城市化中后期阶段。如何在新的发展条件下进行城市滨水地区的更新与提升,充分发挥河道水系的生态价值、经济价值和人文价值,体现"人民城市"的发展理念,成为当前城市发展中面临... 详细信息

上海的城市建设已经进入一个以精细化、内涵式发展为特征的城市化中后期阶段。如何在新的发展条件下进行城市滨水地区的更新与提升,充分发挥河道水系的生态价值、经济价值和人文价值,体现"人民城市"的发展理念,成为当前城市发展中面临的一项重要课题。文章以上海徐汇区为例,结合全区"蓝色网络"系统规划与更新行动实践,围绕多专业、全要素的技术手段,精细化、实用化的成果表达,可协同、可衔接的工作路径等方面展开分析研究,探索"水—岸—城"联动的滨水地区发展新模式。

关键词：滨水地区城市更新联动发展生态文明上海徐汇区

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墨西哥—美国高果玉米糖浆贸易争端及启示

世界农业 2005年第12期 19-21页

作者：王鲁燕中国农业大学

在贸易自由化进程中,外国产品挤占国内产品的市场份额、冲击和影响国内相应产业是各国普遍担心的问题.因此,如何对进口实施监管和控制,保护和稳定国内产业发展环境,已经成为每个国家必须考虑和解决的问题.作为世界贸易组织新成员,目前... 详细信息

在贸易自由化进程中,外国产品挤占国内产品的市场份额、冲击和影响国内相应产业是各国普遍担心的问题.因此,如何对进口实施监管和控制,保护和稳定国内产业发展环境,已经成为每个国家必须考虑和解决的问题.作为世界贸易组织新成员,目前中国在此领域内还缺乏相应的经验.为此,本文根据世界贸易组织、世界粮农组织和美国农业部经济研究局的参考资料,对墨西哥与美国之间围绕美国高果玉米糖浆的贸易争端案例进行了分析和总结,目的是在处理和应对类似问题时可以有所借鉴.

关键词：美国农业部贸易争端玉米糖浆墨西哥世界贸易组织国内产品产业发展贸易自由化市场份额参考资料