检索结果-南通市图书馆

OWC air chamber performance prediction under impulse turbine damping effects

Science China(Technological Sciences) 2016年第4期59卷 657-666页

作者： LIU Zhen hyun BeomSoo jin Ji Yuan HONG KeyYong LEE YoungYeon Shandong Provincial Key Laboratory of Ocean Engineering Ocean University of China Qingdao Municipal Key Laboratory of Ocean Renewable Energy Ocean University of China College of Ocean Science and Technology Korea Maritime and Ocean University Ocean Plant Research Division Korea Research Institute of Ships and Ocean Engineering

Oscillating water columns(OWCs)are most widely used in coastal wave energy *** air duct opens into the atmosphere through the air turbine,which is the power take-off device,and this results in a pressure drop across the air ***,because of the complex configure of the impulse turbine and its high rotation speed,it is difficult to install it in the experimental simulator and numerical ***,the turbine damping effects on the operation of the OWC air chamber are induced to predict its performance more *** plates are used as a substitute for the impulse turbine as it generates a similar pressure drop and power output;the experimental and numerical pressure drops and output powers are compared.A 3D numerical wave tank based on the two-phase VOF model is established using the commercial CFD code Fluent,which can predict air flow and pressure variations in the chamber and *** surface elevations,air flow velocity and pressure variation inside the chamber with the orifice plate are studied numerically,and validated by the corresponding experimental *** air chamber of the Yongsoo OWC pilot plant is used as the engineering project *** operating performance of the air chamber installed with a 0.428D orifice plate as the substitute for the designed impulse turbine is computed and *** is found that the turbine damping effects will cause around 30%reduction in the peak values of the pneumatic energy output of the OWC air chamber in the resonant wave domain.

关键词： oscillating water column air chamber turbine damping effects pressure drop orifice plate operating performance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

EXPERIMENTAL AND NUMERICAL STUDY FOR HYDRODYNAMIC CHARACTERISTICS OF AN OSCILLATING HYDROFOIL

引用

Journal of Hydrodynamics 2008年第3期20卷 280-287页

作者： LIU Zhen hyun Bcom-soo KIM Moo-rong jin Ji-yuan College of Engineering Ocean University of China Qingdao 266100 China College of Ocean Science and Technology Korea Maritime University Busan 606791 Korea Maritime and Ocean Engineering Research Institute Daejeon 305-343 Korea

The present article reports the experimental Particle Image Velocimetry （PIV） investigation and the corresponding numerical simulation results about the water flow over the oscillating hydrofoil and its unsteady dynamic characters. The experimental study focuses on the effect of mean angles of attack. The comparison between the PIV results and numerical prediction about the flow field using Fluent well demonstrates the capability of CFD on the simulation of the water flow around the pitching hydrofoil. The numerical results indicate that the forced oscillating frequencies have evident effects on the flow separation and vortex shedding. The simulations about the hydrodynamic drag and lift coefficients were also performed.

关键词： Particle Image Velocimetry (PIV) oscillating hydrofoil numerical simulation Fluent flow field force characteristics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Bio-inspired Design and Evaluation of Porous Fences for Mitigating Fugitive Dust

引用

Journal of Bionic Engineering 2020年第2期17卷 370-379页

作者： Li Guo Dongsen Zhao Bo Zhao jin Li jin Tong Yunhai Ma Zhiyong chang Key Laboratory of Bionic Engineering(Ministry of Education of China) Jilin UniversityChangchun 130022China College of Biological and Agricultural Engineering Jilin UniversityChangchun 130022China

Fugitive dust has been recognized as an important contributor to air pollution,and artificial porous fence is one of the most effective management strategies to reduce fugitive dust in open *** improve the shelter effects and efficiency of Particulate Matter(PM)reduction of traditional fences,this study proposed five bionic fences and their capability was evaluated through wind tunnel *** results indicated that all of bionic fences presented better efficiency in reducing wind speed and PM concentrations compared with traditional fences,and they were more efficient in capturing *** the bionic fences,the non-woven cloth material with four-leave opening presented the best capability both in wind speed and PM *** proposed bionic fences may be further developed and studied for future application in capturing fine PM and adapting to the wind.

关键词： bio-inspired fence particulate matter wind tunnel tests

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Static load test and load transfer mechanism study of squeezed branch and plate pile in collapsible loess foundation

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第7期8卷 1110-1117页

作者： GAO Xiao-juan WANG jin-chang ZHU Xiang-rong College of Civil Engineering and Architecture Zhejiang University Hangzhou 310027 China Institute of Architecture Engineering Henan University of Science and Technology Luoyang 471003 China Ningbo Institute of Technology Zhejiang University Ningbo 315005 China

As a special geological phenomenon, the character of collapsible loess foundation is collapsible when penetrated by water. This character leads to the soil losing load bearing capacity largely and may lead to foundation failure. Pile is a popular foundation used in collapsible loess. The squeezed branch and plate pile is a new type of pile developed in recent years and has not be used in a project before. In this paper three squeezed branch and plate piles are tested in collapsible loess after immersion processing. The results may be used for reference in similar construction project, and to provide theoretical references for de- signing of the squeezed branch and plate piles in engineering practice.

关键词： Collapsible loess foundation Squeezed branch and plate pile Immersion processing Full-scale static load test

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimization of formation for multi-agent systems based on LQR

引用

Frontiers of Information Technology & Electronic Engineering 2016年第2期17卷 96-109页

作者： chang-bin YU Yin-qiu WANG jin-liang SHAO School of Automation Hangzhou Dianzi University Hangzhou 310018 China Research School of Engineering The Australian National University Canberra ACT 0200 Australia School of Mathematics Science University of Electronic Science and Technology of China Chengdu 611731 China

In this paper,three optimal linear formation control algorithms are proposed for first-order linear multiagent systems from a linear quadratic regulator(LQR) perspective with cost functions consisting of both interaction energy cost and individual energy cost,because both the collective ob ject(such as formation or consensus) and the individual goal of each agent are very important for the overall ***,we propose the optimal formation algorithm for first-order multi-agent systems without initial physical *** optimal control parameter matrix of the algorithm is the solution to an algebraic Riccati equation(ARE).It is shown that the matrix is the sum of a Laplacian matrix and a positive definite diagonal ***,for physically interconnected multi-agent systems,the optimal formation algorithm is presented,and the corresponding parameter matrix is given from the solution to a group of quadratic equations with one ***,if the communication topology between agents is fixed,the local feedback gain is obtained from the solution to a quadratic equation with one *** equation is derived from the derivative of the cost function with respect to the local feedback *** examples are provided to validate the effectiveness of the proposed approaches and to illustrate the geometrical performances of multi-agent systems.

关键词： Linear quadratic regulator (LQR) Formation control Algebraic Riccati equation (ARE) Optimalcontrol Multi-agent systems

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of Oral Chinese Medicine Combined with Western Medicine on Cancer Pain:A Meta-Analysis

引用

Chinese Journal of Integrative Medicine 2021年第9期27卷 713-720页

作者： WANG Yao-han chang jin-yuan FENG Li Traditional Chinese Medicine Department National Cancer Center/Cancer HospitalChinese Academy of Medical Science and Peking Union Medical CollegeBeijing(100021)China China Academy of Chinese Medical Sciences Beijing(100700)China Depatment of Oncology Beijing Hospital of Integrated Traditional Chinese and Western MedicineBeijing(10039)China

Objective:To assess the effect of oral Chinese medicine(OCM)combined with Western medicine(WM)on cancer ***:Pub Med,Embase,Cochrane Library,Clinical Trials Registry Platform,Chinese National Knowledge Infrastructure(CNKI),Wanfang and VIP databases were searched from their inception to September *** controlled trials(RCTs)treating cancer pain by Chinese medicine(CM)combined with WM were *** primary outcome were total pain relief rate and the quality of life(QOL),and the other outcomes were the average daily dosage of analgesics,the primary time of pain,the analgesic duration time,and adverse *** methodological quality of RCTs was assessed in accordance with Cochrane 5.1.0 handbook of systematic reviews of *** level was assessed by the Grades of Recommendation,Assessment,Development and Evaluation(GRADE)***:There were 1,087 patients in the 14 studies,with 544 in the experiment group and 543 in the control *** studies were all conducted in China,and published between 2006 and *** with the WM,OCM combined with WM could significantly relieve the cancer pain risk ratio(RR)=1.43,95% confidence interval(CI):1.32,1.56,improve QOL(RR=8.57,95%CI:4.25,12.89),decrease the primary time of pain(RR=-0.20,95%CI:-0.24,-0.16),prolong the analgesic duration time(RR=3.47,95%CI:2.09,4.85),reduce the dosage of analgesics(RR=-19.52,95%CI:-36.32,-2.72),and reduce side events(RR=0.49,95%CI:0.37,0.65).Evidence levels for total pain relief rate,primary time of pain and side events were low,evidence level for QOL,analgesic duration time and average daily dosage of analgesics were very ***:Compared with the WM,OCM combined with WM could significantly relieve the cancer pain,improve the QOL,decrease the primary time of pain,prolong the analgesic duration time,reduce the dosage of analgesics and side *** evidence levels were low or very low.

关键词： oral Chinese medicine cancer pain clinical trial meta-analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on the Mechanism of the Integration of Urban and Rural Development from the View of Elements Flow

引用

学术界 2016年第6期 285-290页

作者： chang Ye jin Tianlin China Center for Industrial Security Research Beijing Jiaotong University Beijing 100044 School of Economics and Management Northwest University Xi'an Shaanxi 710127

Fromthe enterprise,individual and government,which are the three main economic behavior subject,this paper analysis factors impact of flow behavior main body and the change of the objective function,constraint function and the impact of the change of behavior equation,and then summarizes their effects on the integration of urban and rural development,to build fromexogenous shocks to the endogenous to adapt to the economic decision-making framework,clarify elements flow affect the running mechanismof the urban-rural integration.

关键词：城乡一体化发展流动行为运行机制经济决策行为主体目标函数约束函数城乡发展

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unilateral versus bilateral Y-type stent-in-stent metal stent insertions in inoperable malignant hilar biliary strictures:A multicenter retrospective study

引用

Hepatobiliary & Pancreatic Diseases International 2021年第6期20卷 561-567页

作者： Ik hyun Jo chang-Nyol Paik Dae Bum Kim Jaesin Lee Jong Yul Lee Jae Hyuck chang Kyu-hyun Paik Won-Suk Park Department of Internal Medicine College of MedicineSt.Vincent’s HospitalThe Catholic University of KoreaSeoulKorea Department of Internal Medicine College of MedicineIncheon St.Mary’s HospitalThe Catholic University of KoreaSeoulKorea Department of Internal Medicine College of MedicineBucheon St.Mary’s HospitalThe Catholic University of KoreaSeoulKorea Department of Internal Medicine College of MedicineDaejeon St.Mary’s HospitalThe Catholic University of KoreaSeoulKorea

Background:To date,there is controversy regarding unilateral versus bilateral stent placement in patients with malignant hilar biliary strictures(MHBSs).The aim of this study was to compare the clinical outcomes and complications of unilateral and bilateral(stent-in-stent method)stent placements for these ***:We conducted a multicenter retrospective analysis of patients with inoperable MHBS who underwent endoscopic self-expandable metal stent(SEMS)placement from January 2009 to December *** groups classified according to the stent procedure method were compared for demographic,procedural,and postprocedure *** analysis for patency loss and overall survival was also ***:A total of 236 subjects were included.A superior technical success rate was found in the unilateral stent group(98.8%vs.82.5%,P<0.001),whereas the clinical success rate was higher in the bilateral group(85.7%vs.70.5%,P=0.028).There was no significant difference with respect to complications or patency loss,and the bilateral group had better overall survival(P<0.01).In the Cox proportional hazard model,MHBSs from lymph node compression were associated with a higher risk of death(HR=9.803,P=0.003).In contrast,bilateral SEMS insertion showed reduced postprocedural mortality(HR=0.316,P=0.001).Conclusions:Y-type stent-in-stent bilateral SEMSs are technically difficult but demonstrated more favorable overall survival for palliative bile drainage of inoperable MHBS patients compared to unilateral insertions.

关键词： Cholestasis Extrahepatic neoplasm Cholangiopancreatography Endoscopy Self-expandable metal stents

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of undissolved second-phase particles on dynamic recrystallization behavior of Mg–7Sn–1Al–1Zn alloy during low-and high-temperature extrusions

引用

Journal of Materials Science & Technology 2021年第12期71卷 87-97页

作者： hyun Ji Kim Sang-Cheol jin Jae-Gil Jung Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu41566Republic of Korea Implementation Research Division Korea Institute of Materials ScienceChangwon51508Republic of Korea

This study investigates the effects of fine and coarse undissolved particles in a billet of the Mg–7 Sn–1 Al–1 Zn(TAZ711)alloy on the dynamic recrystallization(DRX)behavior during hot extrusion at low and high temperatures and the resultant microstructure and mechanical properties of the *** this end,partially homogenized(PH)and fully homogenized(FH)billets are extruded at temperatures of250 and 450°*** PH billet contains fine and coarse undissolved Mg_(2) Sn particles in the interdendritic region and along the grain boundaries,*** fine particles(<1μm in size)retard DRX during extrusion at 250°C via the Zener pinning effect,and this retardation causes a decrease in the area fraction of dynamically recrystallized(DRXed)grains of the extruded *** addition,the inhomogeneous distribution of fine particles in the PH billet leads to the formation of a bimodal DRXed grain structure with excessively grown grains in particle-scarce *** contrast,in the FH billet,numerous nanosized Mg_(2) Sn precipitates are formed throughout the material during extrusion at 250°C,which,in turn,leads to the formation of small,uniform DRXed grains by the grain-boundary pinning effect of the *** the PH billet is extruded at the high temperature of 450°C,the retardation effect of the fine particles on DRX is weakened by their dissolution in theα-Mg matrix and the increased extent of thermally activated grain-boundary *** contrast,the coarse Mg_(2) Sn particles in the billet promote DRX during extrusion through the particle-stimulated nucleation phenomenon,which results in an increase in the area fraction of DRXed *** both low and high extrusion temperatures,the extruded material fabricated using the PH billet,which contains both fine and coarse undissolved particles,has a lower tensile strength than that fabricated using the FH billet,which is virtually devoid of second-phase *** lower strength of the former is attributed mai

关键词： Mg–Sn alloy Second-phase particle Extrusion Homogenization Dynamic recrystallization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microstructure and mechanical properties in core of a carburizing 20CrNi2MoV bearing steel subjected to cryogenic treatment

引用

Journal of Iron and Steel Research International 2021年第3期28卷 360-369页

作者： chang-sheng Li Bin-zhou Li Xin jin Yu Wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina Ansteel Group Ansteel Beijing Research InstituteBeijing102211China

Microstructure and mechanical properties in core of a carburizing 20CrNi2MoV bearing steel subjected to cryogenic treatment were *** treatment sample was quenched and tempered at 180℃ for 2 *** treatment samples were quenched,cryogenically treated at−80 and−196℃ for 4 h,slowly returned to room temperature and thereafter tempered at 180℃ for 2 h,and finally tempered at 180℃ for 2 *** scanning electron microscope,electron backscattering diffraction,X-ray diffraction and transmission electron microscope were adopted for microstructure *** results show that cryogenic treatment increases the fraction of high-angle grain boundaries and the precipitation of finely dispersed carbides in the matrix,decreases the volume fraction of inter-lath retained austenite,and hence improves the strength and *** with the conventional treatment,the hardness,yield strength and ultimate tensile strength of the steel after cryogenic treatment are increased by 11.7%,12.6%and 18.3%,respectively,while the impact energy is decreased by 9.8%.

关键词： Bearing steel Cryogenic treatment Lath martensite Retained austenite Mechanical property

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：