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海流作用下沉管—双驳船沉放系统沉放过程的阻力特性分析

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船舶力学 2015年第11期19卷 1318-1324页

作者：李艳伍绍博李欣上海交通大学海洋工程国家重点实验室上海200030 中国交通建设港珠澳大桥岛隧工程项目总经理部

文章通过CFD方法对海流作用下沉管管节与双驳船组成的沉放系统在不同沉放水深时的阻力进行分析,采用RANS方程和SST k-ε湍流模型,利用试验结果验证所用模型和方法的正确性。结合沉放过程三个典型工况,分析90°来流时的流场变化对阻力特... 详细信息

文章通过CFD方法对海流作用下沉管管节与双驳船组成的沉放系统在不同沉放水深时的阻力进行分析,采用RANS方程和SST k-ε湍流模型,利用试验结果验证所用模型和方法的正确性。结合沉放过程三个典型工况,分析90°来流时的流场变化对阻力特性变化产生的影响。结果表明数值结果与试验结果差异较小,驳船和沉管之间的相对位置、沉管沉放深度对流阻力大小影响较大。

关键词：沉管管节沉放过程 CFD 流阻力流场分布

Influence of yttrium on the structure and magnetostriction of Fe_(83)Ga_(17) alloy

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International Journal of Minerals,Metallurgy and Materials 2012年第9期19卷 849-855页

作者： Xi-ming Xiao Xue-xu Gao Ji-heng li Jian-xin Xie State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Polycrystalline Fe83Ga17 alloy rods with various amounts of yttrium were prepared by high vacuum induction melting. It is found that yttrium addition has a significant effect on the structure and magnetostriction of Fes3Ga17 alloy. The small addition of yttrium alters the solidification character and the grain shape of Fe83Ga17 alloy, and as a result, columnar grains with the 〈100〉 preferential direction are pro- duced. Yttrium addition improves the magnetostrictive performance of the as-cast Fes3Ga17 alloy. The magnetostriction values of the as-cast alloy with 0.32at% and 0.64at% yttrium addition go up to 119×10^-6 and 137×10^-6 under 15 MPa compressive stress, respectively. The energy dispersive spectroscopy （EDS） result shows that almost all of the yttrium atoms exist in the Y2Fe17-xGax phase. A small amount of this kind of secondary phase cannot obviously increase the saturate magnetic field.

关键词： gallium alloys iron alloys yttrium magnetostfiction supercooling polycrystallirte materials

Intrinsic anomalous spin Hall effect

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Science China(Physics,Mechanics & Astronomy) 2023年第2期66卷 115-121页

作者： Ping li Jing-Zhao Zhang Zhi-xin Guo Tai Min Xiangrong Wang State Key Laboratory for Mechanical Behavior of Materials Centerfor Spintronicsand Quantum SystemSchool of Materials Science and EngineeringXi'an Jiaotong UniversityXi'an 710049China Key Laboratory for Computational Physical Sciences(Ministry of Education) Fudan UniversityShanghai 200433China Physics Department The Hong Kong University of Science and TechnologyHong Kong 999077China The Hong Kong University of Science and Technology Shenzhen Research Institute Shenzhen 518057China

Charge-spin interconversion in magnetic materials is investigated by using the first-principles *** addition to the conventional spin Hall effect(SHE) that requires mutual orthogonality of the charge current,spin-flow direction,and spin polarization,the recently proposed anomalous SHE(ASHE) is confirmed in Mn2Au and *** interaction of the order parameter with conduction electrons leads to sizeable non-zero spin Berry curvatures that give rise to anomalous spin Hall conductivity(ASHC).Our calculations show that the ASHE is intrinsic and originates from the order-parameter-controlled spin-orbit interaction,which generates an extra anomalous effective field.A useful relationship among the order parameter,the spin Berry curvature,and the ASHC is *** findings provide a new avenue for generating and detecting arbitrary types of spin currents.

关键词： field Berry effect

Understanding the electrode reaction process of dechlorination of 2,4-dichlorophenol over Ni/Fe nanoparticles: Effect of pH and 2,4-dichlorophenol concentration

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Journal of Environmental Sciences 2019年第10期31卷 13-20页

作者： Kaiyuan Zheng Yuqiao Song Xu Wang xin li Xuhui Mao Dihua Wang School of Resources and Environmental Sciences Wuhan University Wuhan 430079 China Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and Energy Wuhan University Wuhan 430079China

Herein,with the exploitation of iron and nickel electrodes,the 2,4-dichlorophenol(2,4-DCP)dechlorinating processes at the anode and cathode,respectively,were separately studied via various electrochemical techniques(e.g.,Tafel polarization,linear polarization,electrochemical impedance spectroscopy).With this in mind,Ni/Fe nanoparticles were prepared by chemical solution deposition,and utilized to test the dechlorination activities of 2,4-DCP over a bimetallic *** the iron anode,the results showed that higher 2,4-DCP concentration and solution acidity aggravated the corrosion within the *** charge transfer resistance(Rct)values of the iron electrode were 703,473,444,and 437Ω·cm2 for the initial 2,4-DCP concentrations of0,20,50,and 80 mg/L,*** the bulk pH of the 2,4-DCP solution varied from 3.0,5.0to 7.0,the corresponding Rct values were 315,376,and 444Ω·cm2,*** the nickel cathode,the reduction current densities on the electrode at-0.75 V(*** calomel electrode)were 80,106,and 111μA/cm2,for initial 2,4-DCP concentrations of 40,80,and125 mg/*** dechlorination experiments demonstrated that when the initial pH of the solution was 7.0,5.0,and 3.0,the dechlorination percentage of 2,4-DCP by Ni/Fe nanoparticles was 62%,69%,and 74%,respectively,which was in line with the electrochemical experiments.10 wt.%Ni loading into Ni/Fe bimetal was affordable and gave a good dechlorination efficiency of 2,4-DCP,and fortunately the Ni/Fe nanoparticles remained comparatively stable in the dechlorination processes at pH 3.0.

关键词： 2,4-Dichlorophenol(2,4-DCP) Dechlorination Corrosion Catalytic hydrogenation Ni/Fe particles

Holographic Dark Energy Model is Consistent with Pantheon SN Ia Data

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Communications in Theoretical Physics 2019年第4期71卷 421-426页

作者： xin li Su-Ping Zhao li Tang Hai-Nan lin Department of Physics Chongqing University

We constrain three cosmological models,i.e.,ACDM model, holographic dark energy(HDE) model and R_h = ct model by using the recent Pantheon compilation of type la supernovae(SN la), the direction measurements of Hubble parameter H(z), and the baryon acoustic oscillations(BAO). The spatial curvature is considered in the ACDM model and the HDE model. We show that the HDE model in a spatially flat and HDE dominate universe has the same behavior as Rh = ct model if the characteristic parameter of the HDE model C_0 approaches to infinity. Numerical results show that the ACDM model is the best favoured one among the three models. The HDE model is consistent with observational data, the best fitting value of C_0 is around 0.8, which implies that the Rh = ct model should be modified to be compatible with the present cosmological observational data. Combing all the datasets, we give strict constraint on the Hubble constant,where h_0=0.694 ± 0.020 for the ACDM model and h_0= 0.689 ±0.019 for the HDE *** results imply that the tension of Hubble constant between Planck collaborations and Riess et al. has been partially relaxed. The constraint on the spatial curvature is also given,where Ω_(k0) =-0.066 ± 0.165 for the ACDM model andΩ_(k0)=0.029 ± 0.067 for the HDE model.

关键词： holographic dark energy cosmological observations supernova general

Software quality assessment model: a systematic mapping study

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Science China(Information Sciences) 2019年第9期62卷 5-22页

作者： Meng YAN xin XIA Xiaohong ZHANG ling XU Dan YANG Shanping li College of Computer Science and Technology Zhejiang University School of Software Engineering Chongqing University Faculty of Information Technology Monash University

Quality model is regarded as a well-accepted approach for assessing, managing and improving software product quality. There are three categories of quality models for software products, i.e., definition model, assessment model, and prediction model. Quality assessment model(QAM) is a metric-based approach to assess the software quality. It is typically regarded as of high importance for its clear method on how to assess a system. However, the current state-of-the-art in QAM research is under limited *** address this gap, the paper provides an organized and synthesized summary of the current QAMs. In detail, we conduct a systematic mapping study(SMS) for structuring the relevant articles. We obtain a total of 716 papers from the five databases, and 31 papers are selected as relevant studies at last. In summary, our work focuses on QAMs from the following aspects: software metrics, quality factors, aggregation methods,evaluation methods and tool support. According to the analysis results, our work discovers five needs that researchers in this area should continue to address:(1) new method and criteria to tailor a quality framework(i.e., structure of software metrics and quality factors) according to different specifics,(2) systematic investigations on the effectiveness, strength and weakness of different aggregation methods to guide the method selection in different context,(3) more investigations on evaluating QAMs in the context of industrial cases,(4) further investigations or real-world case studies on the QAMs related tools, and(5) building a public and diverse software benchmark which can be adopted in different application context.

关键词： software quality systematic mapping study quality assessment model aggregation method

A Time/Space Separation Based 3D Fuzzy Modeling Approach for Nonlinear Spatially Distributed Systems

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International Journal of Automation and computing 2018年第1期15卷 52-65页

作者： Xian-Xia Zhang Zhi-Qiang Fu shao-Yuan li Tao Zou Bing Wang Shanghai Key Laboratory of Power Station Automation Technology School of Mechatronics and AutomationShanghai University Institute of Automation Shanghai Jiao Tong University Shenyang Institute of Automation Chinese Academy of Sciences

Spatially distributed systems （SDSs） are usually infinite-dimensional spatio-temporal systems with unknown nonlinearities. Therefore, to model such systems is difficult. In real applications, a low-dimensional model is required. In this paper, a time/space separation based 3D fuzzy modeling approach is proposed for unknown nonlinear SDSs using input-output data measurement. The main characteristics of this approach is that time/space separation and time/space reconstruction are fused into a novel 3D fuzzy system. The modeling methodology includes two stages. The first stage is 3D fuzzy structure modeling which is based on Mamdani fuzzy rules. The consequent sets of 3D fuzzy rules consist of spatial basis functions estimated by Karhunen-Love decomposition. The antecedent sets of 3D fuzzy rules are used to construct temporal coefficients. Going through 3D fuzzy rule inference, each rule realizes time/space synthesis. The second stage is parameter identification of 3D fuzzy system using particle swarm optimization algorithm. After an operation of defuzzification, the output of the 3D fuzzy system can reconstruct the spatio-temporal dynamics of the system. The model is suitable for the prediction and control design of the SDS since it is of low-dimension and simple nonlinear structure. The simulation and experiment are presented to show the effectiveness of the proposed modeling approach.

关键词： Spatially distributed system (SDS) system identification 3D fuzzy system Karhunen-Love decomposition particleswarm optimization (PSO).

Direct evidence for competition between metastable ω and equilibrium α phases in aged β-type Ti alloys

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Rare Metals 2014年第4期33卷 390-393页

作者： Shun Guo Qing-Kun Meng Hong-Ping li xin-Qing Zhao Institute for Advanced Materials School of Materials Science and EngineeringJiangsu University School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics

Precipitation response of a recently developed β-type Ti-25Nb-2Mo-4Sn alloy （wt%） during aging was investigated in detail. Experimental results indicate that the metastable co or equilibrium α phase can form alternatively even under the same aging condition, depending on the condition prior to the aging, i.e., solution treatment or severe cold rolling. This provides, for the first time, the direct evidence for the competition between ω and α in aged β-type Ti alloys. This peculiar aging response is found to be closely related to high-density dislocations and grain boundaries which suppress the formation of ω but favor the precipitation of fine α phase.

关键词： β-Type Ti alloy Phase competition o~ Phase at Phase

Bis-(8-hydroxyquinoline) mercury nanoribbons: preparation,characterization and photoconductivity

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Frontiers of Optoelectronics 2010年第3期3卷 228-231页

作者： li liU Mingwang shao Xiuhua WANG Anhui Key Laboratory of Functional Molecular Solids College of Chemistry and Materials ScienceAnhui Normal University College of Biochemical Engineering Anhui Polytechnic University Functional Nano and Soft Materials Laboratory Soochow University

Bis-(8-hydroxyquinoline) mercury nanoribbons with average width of 300 nm, thickness of 50 nm and length of up to tens of micrometers were synthesized by a facile solvothermal method. X-ray powder diffraction and Fourier transform infrared spectrum were employed to determine their structure. The conductivity of a bundle of nanoribbons was also measured, which exhibited linear current-voltage characteristics and excellent photoresponse to light, indicating their potential applications in photoswitch nano-devices in the future.

关键词： 5d\95\8a\c5\hcm0000169107.html