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Numerical investigation on the effects of current headings on vortex induced motions of a semi-submersible

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Journal of Hydrodynamics 2022年第3期34卷 382-394页

作者： wei-wen Zhao zhi-yuan wei De-cheng Wa Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Marine Design&Research Institute of China Shanghai200011China Ocean College Zhejiang UniversityZhoushan316021China

In this paper,numerical simulations on vortex-induced motions(VIM)of a semi-submersible at two different current headings are conducted over a wide range of current *** simulations are performed with the computational fluid dynamics(CFD)solver VIM-FOAM-SJTU which is an in-house solver developed based on the OpenFOAM *** turbulent flows are resolved with a shear stress transport-delayed detached eddy simulation(SST-DDES)*** decay tests for transverse and yaw motion are performed in calm still water to make sure the equivalent stiffness is setup *** the results of VIM,including motion response,forces and moments,and flow patterns are presented and analyzed *** including transverse,in-line and yaw motion at different current headings and velocities are *** vorticity in the wake regions at different time stamps are also illustrated for different current headings and velocities.

关键词： Vortex-induced motions(VIM) vortex-induced yaw vim-FOAM-SJTU solver Reynolds stress

Low-thermal-conductivity thermal barrier coatings with a multi-scale pore design and sintering resistance following thermal exposure

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Rare Metals 2020年第4期39卷 352-367页

作者： wei-wei Zhang zhi-yuan wei Li-yuan Zhang Ya-Zhe Xing Qiang Zhang School of Materials Science and Engineering Chang'an UniversityXi'an 710064China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi'an 710049China College of Chemistry and Chemical Engineering Neijiang Normal UniversityNeijiang 641112China AECC Beijing Institute of Aeronautical Material Beijing 100095China

High-insulation,long-life thermal barrier coatings(TBCs)decrease the service temperature of superalloys and improve the service life of gas *** in the thermal insulation properties of the coating mainly depends on the optimization of the TBC *** important challenge for TBCs is maintaining a high performance during thermal exposure without degradation,as the pore-rich structure of the topcoat would inevitably be transformed by sintering.A low-thermalconductivity anti-sintering coating can overcome the tradeoff between thermal insulation and sinter *** this review,the design,preparation,and serviceability evaluation of a low-thermal-conductivity anti-sintering coating will be ***,directions for potential development are *** paper provides a comprehensive understanding of the structured tailoring of TBCs for better thermal insulation and anti-sintering performance.

关键词： Thermal barrier coatings Multi-scale pore Sintering resistance Low thermal conductivity

基于SBAS-InSAR技术的高原地区冰湖堆积体稳定性分析

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地质灾害与环境保护 2024年第2期35卷 106-111页

作者：魏松韦志远路涵裕成都理工大学地质灾害防治与地质环境保护国家重点实验室成都610059 华东勘测设计院(福建)有限公司福州350003

冰湖作为陆地水体的重要组成部分,能对气候变化做出较敏感的反应,溃决后将对生态和人们财产安全造成严重威胁。获取覆盖监测区近3 a来的73景Sentinel-1升轨数据,采用SBAS-InSAR(短基线干涉测量技术)对监测区13个较大的冰湖堆积体进行形... 详细信息

冰湖作为陆地水体的重要组成部分,能对气候变化做出较敏感的反应,溃决后将对生态和人们财产安全造成严重威胁。获取覆盖监测区近3 a来的73景Sentinel-1升轨数据,采用SBAS-InSAR(短基线干涉测量技术)对监测区13个较大的冰湖堆积体进行形变监测。结果表明:监测区绝大部分地方形变速率为-10~20 mm/a,极少部分地方形变速率较大,监测区整体处于稳定状态;冰湖L9和L10周围有少量大于30 mm/a的形变点,结合典型形变点时序分析结果,堆积体近1 a多来累积形变量发生了收敛,最终累积形变量较小,稳定性较好,其余冰湖堆积体形变较小,稳定性较好。研究成果可对该区域生态环境保护及防灾减灾方面提供一定的参考。

关键词：冰湖堆积体 SBAS-InSAR 形变监测稳定性

Proton Orbital[541]1/2 and Backbending in ^(178)W

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Communications in Theoretical Physics 2008年第9期50卷 715-718页

作者： wei zhi-yuan LIU Shu-Xin School of Physics Peking University Beijing 100871 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Collisions Lanzhou 730000 China

The microscopic mechanism of nine experimentally observed bands in ^178W is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions. The experimental results, including the moments of inertia and angular momentum alignments of nine bands in ^178W, are reproduced well by the particle-number conserving calculations, in which no free parameter is involved. Calculations demonstrate that occurrence of sharp backbending comes mainly from the contribution of high-j intruder orbitals vi13/2 or πh11/2 and their interference effect with orbitals near the Fermi surface. Theω variation of the occupation probability of each cranked orbital and the contribution to moment of inertia from each cranked orbital are analyzed.

关键词： backbending cranked shell model moment of inertia pairing interaction

Single-atom Ag-loaded carbon nitride photocatalysts for efficient degradation of acetaminophen:The role of Ag-atom and O_(2)

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Journal of Environmental Sciences 2024年第5期139卷 12-22页

作者： Yi yuan Wen-Long Wang zhi-wei Wang Jin Wang Qian-yuan Wu Key Laboratory of Microorganism Application and Risk Control of Shenzhen Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental SafetyInstitute of Environment and EcologyShenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Shenzhen Environmental Science and New Energy Technology Engineering Laboratory Tsinghua-Berkeley Shenzhen InstituteShenzhen 518055China College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071China

Carbon nitride has been extensively used as a visible-light photocatalyst,but it has the disadvantages of a low specific surface area,rapid electron-hole recombination,and relatively low light *** this study,single-atom Ag was successfully anchored on ultrathin carbon nitride(UTCN)via thermal polymerization,the catalyst obtained is called *** Ag hardly changed the carbon nitride's layered and porous physical *** exhibited efficient visible-light photocatalytic performances in the degradation of various recalcitrant pollutants,eliminations of 85% were achieved by visible-light irradiation for *** with Ag improved the photocatalytic performance of UTCN by narrowing the forbidden band gap from 2.49 to 2.36 e V and suppressing electron-hole pair *** addition,Ag doping facilitated O_(2) adsorption on UTCN by decreasing the adsorption energy from -0.2 to -2.22 e V and favored the formation of O_(2)^(·-).Electron spin resonance and radical-quenching experiments showed that O_(2)^(·-)was the major reactive species in the degradation of Acetaminophen(paracetamol,APAP).

关键词： Ag single atom Carbon nitride Photocatalysis Visible light Adsorption energy Reactive species

Effect of lanthanum on inclusions in non-oriented electrical steel slabs

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Journal of Iron and Steel Research International 2024年第7期31卷 1680-1691页

作者： Qiang Ren zhi-yuan Hu Yun-xia Liu wei-cheng Zhang Zi-qi Gao Li-feng Zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Research and Development Department Shougang Zhixin Qian'an Electromagnetic Material Co.Ltd.Qian'an 064400HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

The effect of lanthanum on the characteristics of inclusions in the slab of non-oriented electrical steels was investigated through industrial trials and thermodynamic *** number,size,and chemical composition of inclusions in the surface,one-quarter of thickness and the center of slabs with and without lanthanum addition were statistically analyzed using an automatic inclusion analysis *** the lanthanum-free slab,inclusions were predominately ***_(2)O_(3),MgO,and AlN as well as a small number of Al_(2)O_(3)-MgO-CaO and *** number densities of oxide inclusions and AlN decreased from the surface to the center of the slab,which was ascribed to the difference in cooling intensity during the continuous *** the steel with lanthanum addition,inclusions were modified into LaAlO_(3) and La_(2)O_(2)S and gradually transformed into dual-phase MgO-La_(2)S3 with an increasing distance from the slab surface due to the reaction between the lanthanum-containing inclusion and the steel *** uneven distribution of oxide inclusions along the thickness of the slab was eliminated in the lanthanum-bearing slab because the dissolved oxygen was remarkably decreased by ***-bearing inclusions were more likely to agglomerate AlN by inducing the heterogeneous nucleation of AlN on their surface,while small-size ***_(2)O_(3) inclusions hardly showed a coarsening effect on the size of AlN.

关键词： Lanthanum-Inclusion Non-oriented electrical steel Aluminum nitride Heterogenous nucleation

Growth process,defects,and dopants of bulkβ-Ga_(2)O_(3)semiconductor single crystals

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China Foundry 2024年第5期21卷 491-506页

作者： Yan-shen Wang Ming-zhi Zhu yuan Liu School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology(Ministry of Education) Beijing 100084China

β-gallium oxide(β-Ga2O3),as the typical representative of the fourth generation of semiconductors,has attracted increasing attention owing to its ultra-wide bandgap,superior optical properties,and excellent tolerance to high temperature and *** to the single crystals of other semiconductors,high-quality and large-sizeβ-Ga_(2)O_(3)single crystals can be grown with low-cost melting methods,making them highly *** this review,the growth process,defects,and dopants ofβ-Ga_(2)O_(3)are primarily ***,the growth process(e.g.,decomposition,crucible corrosion,spiral growth,and development)ofβ-Ga_(2)O_(3)single crystals are summarized and compared in ***,the defects ofβ-Ga_(2)O_(3)single crystals and the influence of defects on Schottky barrier diode(SBD)devices are emphatically ***,the influences of impurities and intrinsic defects on the electronic and optical properties ofβ-Ga_(2)O_(3)are also briefly *** this comprehensive analysis,the article offers a concise summary of the current state,challenges and prospects ofβ-Ga_(2)O_(3)single crystals.

关键词： β-Ga_(2)O_(3) single-crystal growth defects dopants semiconductor

Development of component stiffness equations for thread-fixed one-side bolt connections to an enclosed rectangular hollow section column under tension

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 568-586页

作者： Fu-wei WU yuan-Qi LI Department of Structural Engineering Tongji UniversityShanghai 200092China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

The derivation and validation of analytical equations for predicting the tensile initial stiffness of threadfixed one-side bolts(TOBs),connected to enclosed rectangular hollow section(RHS)columns,is presented in this *** unknown stiffness components are considered:the TOBs connection and the enclosed RHS ***,the trapezoidal thread of TOB,as an equivalent cantilevered beam subjected to uniformly distributed loads,is analyzed to determine the associated *** on the findings,the thread-shank serial-parallel stiffness model of TOB connection is *** analysis of the tensile stiffness of the enclosed RHS face due to two bolt forces,the four sidewalls are treated as rotation constraints,thus reducing the problem to a two-dimensional plate *** to the load superposition method,the deflection of the face plate is resolved into three components under various boundary and load *** to the plate deflection theory of Timoshenko,the analytical solutions for the three deflections are derived in terms of the variables of bolt spacing,RHS thickness,height to width ratio,***,the validity of the above stiffness equations is verified by a series of finite element(FE)models of T-stub *** proposed component stiffness equations are an effective supplement to the component-based method.

关键词： initial stiffness component based method thread-fixed one-side bolt rectangular hollow sections analytical equation

Boundary Points,Minimal L^(2)Integrals and Concavity PropertyⅢ—Linearity on Riemann Surfaces and Fibrations over Open Riemann Surfaces

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2091-2152页

作者： Qi An GUAN zhi Tong MI Zheng yuan School of Mathematical Sciences Peking UniversityBeijing 100871P.R.China School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044P.R.China Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190P.R.China

In this article,we consider a modified version of minimal L^(2) integrals on sublevel sets of plurisubharmonic functions related to modules at boundary points,and obtain a concavity property of the modified *** applications,we give characterizations for the concavity degenerating to linearity on open Riemann surfaces and on fibrations over open Riemann surfaces.

关键词： Minimal L^(2)integrals plurisubharmonic functions boundary points weakly pseudoconvex Kähler manifold