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Scattering of Water Waves by Dual Symmetric Inclined Floating Porous Barriers Using the DBEM

China Ocean Engineering 2024年第1期38卷 156-168页

作者： wang li-xian DENG Yan-wen YE Yang-sha DENG Zheng-zhi Key Laboratory of High Performance Ship Technology(Wuhan University of Technology) Ministry of EducationWuhan 430063China School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan 430063China Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province Changsha 410114China Institute of Port Coastal and Offshore EngineeringZhejiang UniversityZhoushan 316021China

The scattering of normally incident water waves by two surface-piercing inclined perforated barriers in water with a uniform finite depth is investigated within the framework of linear water wave *** that thin barriers are zero-thickness,a novel numerical method involving the the coupling of the dual boundary element method(DBEM)with damping layers is *** order to effectively damp out the reflected waves,two damping layers,instead of pseudoboundaries are implemented near the two side boundaries of the computational ***,the modified linearized free surface boundary conditions are formulated and used for solving both the ordinary boundary integral equation as well as the hypersingular boundary integral equation for degenerate *** newly developed numerical method is validated against analytical methods using the matched eigenfunction expansion method for the special case of two vertical barriers or the inclined angle to the vertical being *** influence of the length of the two damping layers has been ***,these findings are also validated against previous results for several *** validation,the numerical results for the reflection coefficient,transmission coefficient and dissipation coefficient are obtained by varying the inclination angle and porosity-effect *** effects of both the inclination angle and the porosity on the amplitudes of wave forces acting on both the front and rear barriers are also *** is found that the effect of the inclination angle mainly shifts the location of the extremal values of the reflection and the transmission ***,a moderate value of the porosity-parameter is quite effective at dissipating wave energy and mitigating the wave loads on dual barriers.

关键词： dual boundary element method inclined perforated floating breakwater reflection coefficient transmission coefficient damping layer

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Symmetries and Mei Conserved Quantities for Nonholonomic Systems with Servoconstraints

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Communications in Theoretical Physics 2009年第1期51卷 1-5页

作者： XIA li-li wang xian-Jun ZHAO xian-lin Department of Physics Henan Institute of Education Zhengzhou 450014 China

This paper concentrates on studying the symmetries and a new type of conserved quantities called Mei conserved quantities for Nonholonomic Systems with Servoconstraints. The criterions of the Mei symmetry, the Noether symmetry, and the lie symmetry are given. The conditions and the forms of the Mei conserved quantities deduced from these three symmetries are obtained. An example is given to illustrate the appfication of the results.

关键词： nonholonomic systems servoconstraints symmetry conserved quantity

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Scattering of Oblique Water Waves by Two Unequal Surface-Piercing Vertical Thin Plates with Stepped Bottom Topography

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China Ocean Engineering 2018年第5期32卷 524-535页

作者： wang li-xian DENG Zheng-zhi wang Chen wang Peng Key Laboratory of High Performance Ship Technology (Wuhan University of Technology) Ministry of Education Departments of Naval Architecture Ocean and Structural EngineeringSchool of TransportationWuhan University of Technology Institute of Port Coastal and Offshore EngineeringOcean CollegeZhejiang University

Based on linear water-wave theory, this study investigated the scattering of oblique incident water waves by two unequal surface-piercing thin vertical rigid plates with stepped bottom topography. By using the matched eigenfunction expansion method and a least square approach, the analytical solutions are sought for the established boundary value problem. The effects of the incidence angle, location of step, depth ratio of deep to shallow waters,and column width between two plates, on the reflection coefficients, the horizontal wave forces acting on the two plates, and the mean surface elevation between the two plates, are numerically examined under a variety of wave conditions. The results show that the existence of the stepped bottom between two plates considerably impacts the hydrodynamic performances of the present system. It is found that the effect of stepped bottom on the reflection coefficient of the present two-plate structure is evident only with waves of the low dimensionless ***, the influence of the step location on the hydrodynamic performance of the present two-plate structure is slight if the step is placed in between the two plates.

关键词： stepped bottom topography two unequal thin vertical rigid plates oblique water waves reflection coefficient wave force

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High temperature corrosion behavior of arc-sprayed aluminum coatings on steel

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 451-454页

作者： SUN Jian-bo wang Yong DONG li-xian College of Mechanical and Electronic Engineering University of Petroleum Dongying 257061 China College of Mechanical and Electronic Engineering University of Petroleum Dongying 257061 China College of Mechanical and Electronic Engineering University of Petroleum Dongying 257061 China

Aluminum coatings were sprayed on the substrate of steel Q235 by arc spraying. The test samples of Q235, Al coatings and Al coatings with seal coat were placed in box type electric resistance furnace at 400, 500,600, 650 ℃ when their oxidation behaviors were studied. And their oxidation kinetics curves were protracted. Microstructure, microhardness, bond strength and distribution of section elements were investigated by optical microscope(OM), Vickers microhardness instrument, electric tensile test machine and EPMA. Al coatings and Al coatings with seal coat can enhance the oxidation-resistance of substrate under 500 ℃. The latter has the best corrosion resistance. The coatings can't protect the substrate against oxidation above 600 ℃. After a long time corrosion there is enriched oxygen element at interface.

关键词： arc spraying Al coating Al coating with seal coat high temperature corrosion oxidation kineticscurve

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园艺疗法对大学生心理素质提升的应用研究

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亚热带植物科学 2024年第1期53卷 72-79页

作者：郭灿丽谢涵王丽娴李东泽浙江理工大学风景园林系浙江杭州310018

探究园艺疗法对大学生心境状态的缓解与心理素质提升的效益,以期为园艺疗法在高校中的推广应用提供参考。通过开展10种园艺活动,运用POMS量表与满意度调查进行量化、质性分析。结果显示,10种园艺活动参与者的心境状态TMD均有所下降,平... 详细信息

探究园艺疗法对大学生心境状态的缓解与心理素质提升的效益,以期为园艺疗法在高校中的推广应用提供参考。通过开展10种园艺活动,运用POMS量表与满意度调查进行量化、质性分析。结果显示,10种园艺活动参与者的心境状态TMD均有所下降,平均降低12.68;植物识别、叶脉书签、植物播种、植物拓印、多肉栽植与香囊制作等活动均能够显著改善大学生的消极情绪;各园艺活动对具体心境状态疲劳(2.50)、抑郁(2.05)与紧张(1.91)情绪改善效果较好,其中植物拓印活动最好,可显著改善6个心境状态;各园艺活动总体满意度评价均值为8.10,总体评价较好,其中香囊制作与多肉栽植的满意度较高。研究表明各园艺活动均对参与者的情绪有一定改善作用,植物识别、植物播种、多肉栽培与香囊制作对参与者的心理状况改善较好;园艺疗法可一定程度地提升大学生心理素质,将园艺疗法运用到大学生心理健康教育具有一定的可行性。

关键词：园艺疗法大学生心理素质干预活动 POMS 心境状态TMD

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基于损伤因子的T形梁桥横向连接构件损伤识别

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兰州理工大学学报 2024年第1期50卷 123-131页

作者：王立宪赵俊豪狄生奎项长生党聪兰州理工大学土木工程学院甘肃兰州730050 浙江中南幕墙科技股份有限公司浙江杭州310051

近年来,装配式T形梁桥在我国广泛应用,对桥梁易损位置横向连接构件损伤识别成为关注的热点问题.将T形梁桥的横隔梁简化成等刚度桥面板,采用弹簧体系模拟横向连接构件的受力变形,考虑横向连接构件剪力、横向力和翼缘板变形的影响,提出装... 详细信息

近年来,装配式T形梁桥在我国广泛应用,对桥梁易损位置横向连接构件损伤识别成为关注的热点问题.将T形梁桥的横隔梁简化成等刚度桥面板,采用弹簧体系模拟横向连接构件的受力变形,考虑横向连接构件剪力、横向力和翼缘板变形的影响,提出装配式T形梁桥横向连接构件损伤因子的理论计算式.将MATLAB理论计算、ANSYS数值模拟和实验的结果进行对比,验证损伤因子的有效性,并通过7种模拟工况和3种实际工况的对比,发现荷载作用位置越接近损伤横向连接构件,损伤识别的精确度越高.

关键词：装配式T形梁桥横向连接构件损伤识别数值分析

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新能源微电网系统功率分配及谐波振荡研究

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兰州石化职业技术大学学报 2024年第3期24卷 27-31页

作者：王理宪张爱茹王威民兰州石化职业技术大学学生处甘肃兰州730060 兰州石化公司质检计量中心甘肃兰州730060 古浪县直滩初级中学甘肃古浪733100

针对“双高”能源微电网系统的特性,根据负载的非线性及负荷的时变性进而会使微电网系统出现谐波,造成系统振荡及无功功率的损耗严重。为了避免该种情况的发生,本文采用电压控制方法和电流控制方法相互结合的方式来对系统谐波振荡问题... 详细信息

针对“双高”能源微电网系统的特性,根据负载的非线性及负荷的时变性进而会使微电网系统出现谐波,造成系统振荡及无功功率的损耗严重。为了避免该种情况的发生,本文采用电压控制方法和电流控制方法相互结合的方式来对系统谐波振荡问题和无功进行分配,其中文中的电压控制方式对微电网系统而言能有效的调节有功功率分配;电流控制方法相比于电压控制而言,主要应用于消除谐波且对无功功率进行分配。相较于传统方法,该方法能通过对系统局部测量,不仅解决了谐波问题,而且对无功功率进行有效标定分配,使系统更简单、更可靠。最后通过实验验证所提方法的正确性。

关键词：微电网电压控制方法无功分配:谐波振荡

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Wave Scattering by Twin Surface-Piercing Plates Over A Stepped Bottom:Trapped Wave Energy and Energy Loss

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China Ocean Engineering 2019年第4期33卷 398-411页

作者： DENG Zheng-zhi wang Chen wang Chi YAO Yu OU Ze-ting wang li-xian Institute of Port Coastal and Offshore Engineering Zhejiang University Zhoushan 316021 China Nanjing Hydraulic Research Institute Nanjing 210029 China School of Hydraulic Engineering Changsha University of Science and Technology Changsha 410114 China Departments of Naval Architecture Ocean and Structural Engineering School of Transportation Wuhan University of Technology Wuhan 430063 China

To evaluate the trapped wave energy and energy loss, the problem of wave scattering by twin fixed vertical surface- piercing plates over a stepped bottom is numerically simulated using the open source package OpenFOAM and the associated toolbox waves2Foam. The volume of fluid (VOF) method was employed to capture the free surface in the time domain. The validation of the present numerical model was performed by comparing with both the analytical and experimental results. The effects of the spacing between two plates and the configuration of stepped bottom on the hydrodynamic characteristics, such as reflection and transmission coefficients, viscous dissipation ratio, and relative wave height between the plates (termed as trapped wave energy), were examined. Moreover, the nonlinear effects of the incident wave height on the hydrodynamic characteristics were addressed as well. The results show that the step configuration can be tuned for efficient-performance of wave damping, and the optimum configurations of the step length B, the step height h1 and the spacing b, separately equaling λ/4, 3h/4, and 0.05h (λ and h are the wavelength and the water depth, respectively), are recommended for the trapping of wave energy.

关键词： OpenFOAM twin surface-piercing plates viscous dissipation wave nonlinearity trapped wave energy

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STYRENE POLYMERIZATION MEDIATED BY CYCliC TRITHIOCARBONATE AS RAFT AGENT

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Chinese Journal of Polymer Science 2006年第6期24卷 593-597页

作者： Qi wang Yi-xian li Jian Hong Zhi-qiang Fan Department of Polymer Science ＆ Engineering Zhejiang University Hangzhou 310027 China

The novel cyclic trithiocarbonate was synthesized by dialkylation of trithiocarbonate anion with 2,2＇- bis（bromomethyl）biphenyl in a two-phase system using an onium salt as a phase-transfer agent. Styrene polymerization was carried out in the presence of cyclic trithiocarbonate （CTTC）. CTTC undergoes ring opening-polymerization and the incorporated trithiocarbonate moiety derived from CTTC performs as the reversible addition-fragmentation chain transfer （RAFT） agent. Through this mechanism, multiblock polys-tyrenes containing various narrow polydispersity blocks can be prepared.

关键词： Cyclic trithiocarbonate Multiblock polymer RAFT polymerization Styrene.

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Erythropoietin Receptor Gene (EPOR) Polymorphisms are Associated with Sow litter Sizes

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Agricultural Sciences in China 2011年第6期10卷 931-937页

作者： ZHANG Long-chao wang li-gang li Yong YAN Hua ZHAO Ke-bin wang li-xian Institute of Animal Science Chinese Academy of Agricultural Sciences Beijing 100193 P.R. China

The erythropoietin receptor （EPOR） has shown to play an important role in fetal survival by promoting the maturation of red blood cells in many studies of uterine capacity and litter size in swine. In this study, we screened the porcine EPOR gene for mutations and identified five single nucleotide polymorphisms （SNPs）： g.705G〉T in intron 1, g.2 373C〉T in intron 4, and g.2 882C〉T, g.3 035A〉G, and g.3 132A〉T in intron 6. We then genotyped 247 Beijing Black （BB） sows and compared the polymorphism data with the litter sizes of 1 375 parities among the sows. At first parity, there was no association of g.2 882C〉T and g.3 132A〉T with litter sizes. However, the CT sows in g.2 882C〉T had 2.13 higher total number born （TNB）（P〈0.01） and 1.81 higher number born alive （NBA）（P〈0.01） than the CC sows and the heterozygous sows in g.3 132A〉T had the highest litter size when compared to the two homozygotes for the later parities （P〈0.05）. In the g.3 035A〉G SNP, for the later parities, the TNB of the sows with the GG genotype was 3.81 higher （P〈0.01） and the NBA was 2.75 higher （P〈0.01） than that with the AA genotype but no difference at first parity. The G allele of the EPOR g.705G〉T SNP was associated with a greater litter size at both the first parity （P〈0.05） and later parities （P〈0.01）. Furthermore, we determined the allele frequencies for this SNP among five Chinese indigenous pig breeds （Erhualian, Laiwu Black, Meishan, Min, and Rongchang） and three western commercial pig breeds （Duroc, Landrace, and Large White）. The G allele of the EPOR g.705G〉T SNP was significantly more common in the more prolific Chinese breeds. These results indicated that the EPOR could be an important candidate gene for litter size and g.705G〉T can serve as a useful genetic marker for improving litter size in both first and later parities in swine.

关键词： erythropoietin receptor litter size pig single nucleotide polymorphism

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