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Experimental study of drag reduction in flumes and spillway tunnels

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Water Science and Engineering 2010年第2期3卷 200-207页

作者： Ying-kui wang Chun-bo JIANG State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 P. R. China

Experiments in an open flume model and spillway tunnel model were carried out using drag reduction techniques. Two drag reduction techniques were adopted in the experiments： polymer addition and coating. The drag reduction effect of a polyacrylamide （PAM） solution and dimethyl silicone oil coating were studied in the flume model experiments, and the results were analyzed. Experiments were then carded out with a model of the Xilnodu Hydropower Station, the second largest dam in China. In order to reduce the resistance, the spillway tunnels were internally coated with dimethyl silicone oil. This is the first time that these drag reduction techniques have been applied to so large a hydraulic model. The experimental results show that the coating technique can effectively increase flood discharge. The outlet velocity and the jet trajectory distance are also increased, which enhances the energy dissipation of the spillway tunnel.

关键词： drag reduction hydraulic model experiment spillway tunnel

Intraoperative management and early post-operative outcomes of patients with coronary artery disease who underwent orthotopic liver transplantation

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Hepatobiliary & Pancreatic Diseases International 2020年第1期19卷 12-16页

作者： Hai-Ying Kong Xian Zhao kui-Rong wang Department of Anesthesiology The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Department of Anesthesiology International HospitalZhejiang UniversityHangzhou 310000China

Background: Coronary artery disease (CAD) is frequently observed in aging end-stage liver disease (ESLD) patients who require orthotopic liver transplantation (OLT). This situation is challenging for both the pa- tients and the medical staff. Methods: We retrospectively studied the case records of 26 ESLD patients with CAD who underwent OLT with total clamping of the inferior vena cava between 2014 and 2018. We analyzed the details of the pre-operative evaluation, intraoperative anesthetic management and post-operative prognosis of these patients. Results: All patients tolerated the anhepatic stage well. Post-reperfusion syndrome (PRS) was observed in 13 patients (50%) and 2 of them were severe but corrected well. ST-segment depression was frequently observed during the anhepatic stage and reperfusion stage. No mortality due to cardiac-related events occurred among the patients during hospitalization. OLT with the modi ed piggyback technique could successfully be performed in ESLD patients with mild and moderate CAD. Conclusions: A thorough evaluation and optimization of recipients, strict monitoring and optimized man-agement of circulation, knowledge of the complicated changes during OLT procedures, and strategies to ameliorate post-reperfusion syndrome favorite the outcomes.

关键词： Orthotopic liver transplantation Coronary artery disease Post-reperfusion syndrome

Spectral matching algorithm based on nonsubsampled contourlet transform and scale-invariant feature transform

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Journal of Systems Engineering and Electronics 2012年第3期23卷 453-459页

作者： Dong Liang Pu Yan Ming Zhu Yizheng Fan kui wang Key Lab of Intelligent Computing ＆ Signal Processing Ministry of Education Anhui University Hefei 230039 E R. China School of Electronics and Information Engineering Anhui University Hefei 230039 P. R. China School of Mathematics and Computation Sciences Anhui University Hefei 230039 P. R. China

A new spectral matching algorithm is proposed by us- ing nonsubsampled contourlet transform and scale-invariant fea- ture transform. The nonsubsampled contourlet transform is used to decompose an image into a low frequency image and several high frequency images, and the scale-invariant feature transform is employed to extract feature points from the low frequency im- age. A proximity matrix is constructed for the feature points of two related images. By singular value decomposition of the proximity matrix, a matching matrix （or matching result） reflecting the match- ing degree among feature points is obtained. Experimental results indicate that the proposed algorithm can reduce time complexity and possess a higher accuracy.

关键词： point pattern matching nonsubsampled contourlet transform scale-invariant feature transform spectral algorithm.

Two Schemes for Probabilistic Remote Preparation of a Four-Particle Entangled Cluster-Type State

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Communications in Theoretical Physics 2014年第3期61卷 305-314页

作者： HOU kui wang Hong-Yan LI Yi-Bao Department of Mathematics and Physics Anhui Jianzhu University Hefei 230601 China

Using partial entangled states as the quantum channel, two schemes for probabilistic remote preparation of the four-particle cluster-type state with real and complex coefficients are presented. In the first scheme, the sender and the receiver share two partial Bell states and one partial three-qubit GHZ stats as the quantum channel, and the sender can help a remote receiver to prepare a four-particle entangled cluster-type state by using three-qubit projective measurements with certain probability. In the second scheme, the quantum channel is composed of two partial three-qubit GHZ states, the remote state preparation(RSP) can be successfully realized via the positive operator valued measure(POVM), and the two-particle projective measurements are also needed in this process. The total success probability and classical communication cost are calculated.

关键词： remote state preparation GHZ state Positive operator-valued measure classical information

轮毂电机再生制动与摩擦制动制动力分配策略研究

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内燃机与配件 2024年第15期 1-5页

作者：楚博士王奎洋王渝甬江苏理工学院汽车与交通工程学院江苏常州213001

为了提高轮毂电机电动汽车再生制动的占比与制动能量回收,提出了一种新的复合制动系统制动力分配策略。首先,针对轮毂电机再生制动和线控摩擦制动的特点,结合车辆参数及ECE法规对制动性能的要求,提出不同条件下的前后轴制动力分配策略... 详细信息

为了提高轮毂电机电动汽车再生制动的占比与制动能量回收,提出了一种新的复合制动系统制动力分配策略。首先,针对轮毂电机再生制动和线控摩擦制动的特点,结合车辆参数及ECE法规对制动性能的要求,提出不同条件下的前后轴制动力分配策略。其次,根据不同制动工况提出集成制动装置内部再生制动和摩擦制动之间的制动力分配策略。最后,在Matlab/Simulink软件中模拟不同工况、不同强度下的制动过程。结果表明:所提策略可以充分利用再生制动的优势,为摩擦制动分担部分制动需求,且在小强度制动时再生制动占比较高。

关键词：轮毂电机线控制动再生制动制动力分配 ECE法规

Effects of Deformation Texture and Twins on the Corrosion Resistance of Rolled AZ31 Mg Alloy Under 5% Uniaxial Compression

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Acta Metallurgica Sinica(English Letters) 2017年第10期30卷 921-930页

作者： Chen wang Hao Ding Bing-Shu wang kui wang Jing-Jing Shi Jun-Feng Chen College of Materials Science and Engineering Fuzhou University

The deformation texture and twin effect of rolled AZ31 Mg alloy on the corrosion resistance in simulated body fluid（SBF） at room temperature were examined by potentiodynamic polarization and electrochemical impedance *** corrosion morphology evolution after being immersed in SBF for 24 h has been analyzed by scanning electron microscope. The results show that the inhomogeneous deformation leaded to the obvious differences in the *** corrosion rate of rolled AZ31 Mg alloy decreased dramatically in the transverse direction（TD） plane, which mainly consisted of {0001} deformation texture, making TD plane be a lower surface energy,and thus a higher corrosion resistance, while the corrosion resistance of the plane with 45° to TD direction（45 TD plane） containing enormous{10-12} tension twins decreased after 5% uniaxial compression. The {10-12} tension twins accelerate the rate of corrosion procedure and pitting corrosion. Moreover, it is suggested that the deformation texture affects the corrosion behavior more than the twins do. This study indicates that the corrosion rate of AZ31 Mg alloy in SBF can be modified by the small uniaxial compression.

关键词： AZ31 Mg alloy Twins Texture Corrosion resistance

Why Do Chinese Private Enterprises Seek Outward Foreign Direct Investment?

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China & World Economy 2023年第4期31卷 200-218页

作者： kui wang Shuang Tao School of Economics Huazhong University of Science and TechnologyChina

China is currently in a period of economic transformation and the reform of the factor market still lags behind that of the product *** study explores the reasons causing China's private enterprise to expand abroad from the perspective of domestic factor market *** data for Chinese listed firms between 2002 and 2020,it examines whether outward foreign direct investment(OFDI)has been undertaken by private enterprises as a response to domestic factor market *** finds that private enterprises located in regions with greater factor market imperfection have had a greater tendency to engage in *** effect has been more pronounced among firms with high productivity or high innovation capability,and among medium and small private enterprises.

关键词： factor market imperfection input factor cost OFDI private enterprises

Density Functional Theory Study on Raman Spectra of Rhodamine Molecules in Different Forms

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Chinese Journal of Chemical Physics 2014年第3期27卷 291-296页

作者： Yong Ma Wei Hu Xiu-neng Song Chuan-kui wang College of Physics and Electronics Shandong Normal University Ji'nan 250014 China Division of Theoretical Chemistry and Biology School of Biotechnology Royal Institute of Technology Stockholm S-106 91 Sweden Department of Chemical Physics University of Science and Technology of China Hefei 230025 China

Rhodamine molecules are one of the most used dyes for applications related to Raman spectroscopy. We have systematically studied Raman spectra of Rhodamine 6G, Rhodamine 123, and Rhodamine B （RhB） molecules using density functional theory. It is found that with BP86 functional the calculated Raman spectra of cationic Rhodamine molecules are in good agreement with corresponding experimental spectra in aqueous solution. It is shown that the involvement of the counter ion, chlorine, and the specific hydrogen bonds has noticeable effects on the Raman spectra of RhB that can partially explain the observed difference between Raman spectra of RhB in solution and on gold surfaces. It also indicates that an accurate description of surface enhanced Raman scattering for Rhodamine molecules on metal surface still requires to take into account the changes induced by the interracial interactions.

关键词： Density functional theory Raman scattering Rhodamine Solvent effect

Single-atomic-site iron on N-doped carbon for chemoselective reduction of nitroarenes

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Nano Research 2022年第1期15卷 603-611页

作者： Guoping Lu Kangkang Sun Yamei Lin Qixuan Du Jiawei Zhang kui wang Pengcheng wang School of Chemical Engineering Nanjing University of Science&TechnologyNanjing 210094China Institute of Chemical Industry of Forest Products Chinese Academy of ForestryNational Engineering Laboratory for Biomass Chemical UtilizationNanjing 210042China School of Food Science and Pharmaceutical Engineering Nanjing Normal UniversityNanjing 210032China College of Materials Science and Engineering Hunan UniversityChangsha 410082China

A facile,gram-scale and sustainable approach has been established for the synthesis of single-atomic-site iron on N-doped carbon(Fe_(SA)@NC-20A)via the pyrolysis of aniline modified FeZn-ZIFs,in which the synthesis of zeolitic imidazolate frameworks(ZIFs)can be accomplished in water at room temperature,and no acid etching is *** as-synthesized catalyst exhibits better performance on the chemoselective hydrogenation of nitroarenes with a broad substrate scope(turnover frequency(TOF)up to 1,727 h^(-1),23 examples)than most of previously reported *** on high-angle annular dark field scanning transmission microscopy(HAADF-STEM)images in combination with X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),electron spin resonance(ESR),and Mossbauer spectroscopy,Fe is dispersed as single atoms via forming FeNx(x=4-6).This work not only determines the active sites of FesA@NC-20A for hydrogenation(FeN4),but also proposes tentative pathways for both N-H activation of hydrazine and the reduction of nitroarene on FeN4 site,both of which are the key steps for the hydrogenation of *** addition,this catalyst shows excellent stability,and no significant activity degradation is observed when recycling for 10 times or restoring in air for 2 months.

关键词： single-atom-site iron zeolitic imidazolate framework the hydrogenation of nitroarene N-doped carbon drug synthesis