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The Defocusing Energy-supercritical NLS in Higher Dimensions

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Acta Mathematica Sinica,English Series 2017年第7期33卷 911-925页

作者： Teng fei zhao The Graduate School of China Academy of Engineering Physics P.O.Box 2101Belting 100088P.R.China

Abstract We consider the defocusing nonlinear SchrSdinger equations iut ＋△u = lulPu with p being an even integer in dimensions d ≥ 5. We prove that an a priori bound of critical norm implies global well-posedness a... 详细信息

关键词： Nonlinear Schr?dinger equation priori bound scattering

Experimental study on the interfacial delamination in a thermal barrier coating system at elevated temperatures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 794-803页

作者： Peng-fei zhao Fu-lin SHANG Department of Engineering Mechanics School of Aerospace Xi 'an Jiaotong University Xi 'an 710049 China

The failure mode and adhesion of thermal barrier coating (TBC) 8YSZ (ZrO2+8% (w/w) Y2O3) deposited on NiCoCrAlTaY bond coat by atmospheric plasma spraying were investigated. A grooved modified three-point bending specimen that can generate a single interface crack to facilitate the control of crack growth was adopted for testing, which was conducted at the ambient temperature of 100 °C. The morphology and composition of fractured surfaces were examined by means of a scanning electron microscopy (SEM) and an energy disperse spectroscopy (EDS). Images and spectrum show that cracks are initiated and propagated exclusively within YSZ layer adjacent to top/bond coat interface. The load-displacement curves obtained exhibit similar shapes that indicate two distinct stages in crack initiation and stable crack growth. Finite element analyses were performed to extract the adhesion strength of the TBCs. The delamination toughness of the plasma-sprayed 8YSZ coatings at 100 °C, in terms of critical strain energy release rate Gc, can be reliably obtained from an analytical solution.

关键词： Thermal barrier coating (TBC) Three-point bending test Finite element analysis Delamination toughness

Characteristics of a coherent jet enshrouded in a supersonic fuel gas

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International Journal of Minerals,Metallurgy and Materials 2020年第2期27卷 173-180页

作者： fei zhao Rong Zhu Wen-rui Wang Key Laboratory of Fluid Interaction with Material University of Science and Technology BeijingBeijing 100083China National Center for Materials Service Safety University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanical Engineer University of Science and Technology BeijingBeijing 100083China

Based on a current coherent jet,this study proposes a supersonic combustion(SC)coherent jet in which the main oxygen jet is surrounded by a supersonic fuel *** characteristics of the proposed coherent jet are analyzed using experimental methods and numerical simulations in the high-temperature environment of electric arc furnace(EAF)*** SC coherent jet achieved stable combustion in the EAF steelmaking *** simulated combustion temperature of the supersonic shrouding methane gas was 2930 K,slightly below the theoretical combustion temperature of methane–oxygen *** high speed and temperature of the supersonic flame effectively weakened the interaction between the main oxygen jet and the external ambient gas,inhibiting the radial expansion of the main oxygen jet and maintaining its high speed and low turbulence over a long *** features improved the impact capacity of the coherent jet and strengthened the stirring intensity in the EAF bath.

关键词： EAF steelmaking coherent jet supersonic shrouding fuel gas supersonic combustion field characteristics

Wire-like nano-polyaniline deposited electrochemically in a reverse micelle electrolyte as a p H sensor

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International Journal of Minerals,Metallurgy and Materials 2015年第10期22卷 1115-1119页

作者： fei zhao Han-dong Jiao Shi-qiang zhao State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Wire-like polyaniline(PANI) films were successfully electrodeposited onto an indium tin oxide(ITO) substrate using a pulse galvanostatic method(PGM) in a reverse micelle electrolyte. The as-prepared PANI films were electrochemically analyzed by cyclic voltammetry and electrochemical impedance spectroscopy in 1 mol·L-1 HCl O4 solution. It is found that the as-prepared PANI films are highly porous, exhibit the diameters of approximately 100 nm and the lengths exceeding 3 μm, and have favorable electrochemical activities. Furthermore, the as-prepared wire-like PANI films show a good linear relationship of the potentiometric response curve over the p H value range of 3–10 with a slope of 74.13 m V·p H-1 in 0.5 mol·L-1 K2HPO4 basal solutions. The results demonstrate that the prepared wire-like PANI films are promising p H sensors.

关键词： electrodeposition polymers sensors thin films

Evaluation of silymarin extract from Silybum marianum in mice: anti-fatigue activity

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Food Science and Human Wellness 2022年第4期11卷 914-921页

作者： Luming Jia fei zhao College of Food Science and Engineering Dalian Ocean UniversityDalian 116023China

Silymarin has been used for centuries for its hepatoprotective properties. The specific objective of this study was to evaluate the anti-fatigue properties of silymarin. The silymarin was administered orally at doses of 50, 100, and 200 mg/kg for 4 weeks;the fatigue level and exercise performance were evaluated using exhaustive swimming time and pole-climbing time, as well as levels of plasma lactate, ammonia, glucose, creatine kinase(CK), serum urea nitrogen(SUN), blood lactic acid(BLA), muscle glycogen(MG), and liver glycogen(LG) contents after an intensive swimming session. The results demonstrated that silymarin treatment decreased the BLA and SUN levels while increased the LG and MG levels. In addition, silymarin decreased plasma lactate and ammonia levels and CK activity after swimming test, this is related to the mechanism that increases energy storage(as glycogen) and release(as blood glucose), and decreases plasma levels of lactate, ammonia, and CK. The observation of the skeletal muscle structures of mice also confirmed that skeletal muscles became more damaged in the control group compared with the silymarin-treated mice after prolonged endurance exercise. Therefore, it is reasonable to infer that silymarin may bear potential pharmacological effects in combating fatigue.

关键词： Silybum marianum Silymarin Anti-fatigue Exhaustion exercise

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Acta Mathematica Sinica,English Series 2014年第10期30卷 1689-1697页

作者： Zhe DONG Ya fei zhao Department of Mathematics Zhejiang University

In this note, we show that avon Neumann algebra M is injective if and only if the weak＊ similarity degree d.（M） ≤ 2.

关键词： Weak* similarity degree injective von Neumann algebra operator space

ANALYSIS ON A NUMERICAL SCHEME WITH SECOND-ORDER TIME ACCURACY FOR NONLINEAR DIFFUSION EQUATIONS

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Journal of Computational Mathematics 2021年第5期39卷 777-800页

作者： Xia Cui Guangwei Yuan fei zhao Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsP.O.Box 8009-26Beijing 100088China College of Science North China University of TechnologyBeijing 1OO144China Graduate School of China Academy of Engineering Physics Beijing 100088China

A nonlinear fully implicit finite difference scheme with second-order time evolution for nonlinear diffusion problem is *** scheme is constructed with two-layer coupled discretization(TLCD)at each time *** does not stir numerical oscillation,while permits large time step length,and produces more accurate numerical solutions than the other two well-known second-order time evolution nonlinear schemes,the Crank-Nicolson(CN)scheme and the backward difference formula second-order(BDF2)*** developing a new reasoning technique,we overcome the difficulties caused by the coupled nonlinear discrete diffusion operators at different time layers,and prove rigorously the TLCD scheme is uniquely solvable,unconditionally stable,and has second-order convergence in both s-pace and *** tests verify the theoretical results,and illustrate its superiority over the CN and BDF2 schemes.

关键词： Nonlinear diffusion problem Nonlinear two-layer coupled discrete scheme Second-order time accuracy Property analysis Unique existence Convergence

A Hydraulic Performance Comparison of Centrifugal Pump Operating in Pump and Turbine Modes

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Journal of Thermal Science 2020年第6期29卷 1594-1605页

作者： DAI Cui DONG Liang LIN Haibo zhao fei School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013China Sichuan Provincial Key Lab of Process Equipment and Control Sichuan University of Science&EngineeringZigong 643000China Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang 212013China School of Mechanical Research Center of Technology Wuxi Institute of TechnologyWuxi 214121China

The modifications of impeller may show diverse impact on centrifugal pump operating in pump and turbine *** clarify this problem,the hydraulic performance of a low specific speed centrifugal pump operating in both modes was firstly obtained by CFD method and verified by ***,based on the single-factor design method,a series of calculations have been conducted to identify the effects of impeller geometry parameters on the hydraulic performance in different *** variations of head,shaft power and hydraulic efficiency curves with different impeller parameters were *** is found that compared with turbine,the pump shows a more obvious variation of *** outlet angle has positive impact both on the head consumed by pump or generated by *** change of turbine shaft power is apparently smaller than that of pump for different impeller geometry *** the outlet width somewhat changes the turbine shaft *** hydraulic efficiency in both modes shows different variation under different impeller geometric parameters,while the hydraulic efficiency of both modes is reduced with the outlet angle ***,the response amount of hydraulic efficiency caused by certain change of impeller parameters was estimated by sensitivity analysis *** is found that only the appropriate blade number and outlet width can improve the hydraulic performance both in pump and turbine ***,the hydraulic loss,skin friction loss and theoretical analysis were performed to explore the reason of hydraulic performance variation due to different impeller *** change of slip factor,impeller inlet area,impeller outlet area or hydraulic loss results in the change of hydraulic performance in both *** results can be useful for hydraulic performance improvement for both pump and turbine modes through impeller geometry modification.

关键词： Computational Fluid Dynamics centrifugal pump impeller modification pump mode turbine mode

Extended DMPs Framework for Position and Decoupled Quaternion Learning and Generalization

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 227-239页

作者： Zhiwei Liao fei zhao Gedong Jiang Xuesong Mei State Key Laboratory for Manufacturing System Engineering Xi’an Jiaotong UniversityXi’an 710049China Shaanxi Key Laboratory of Intelligent Robots and School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China

Dynamic movement primitives(DMPs)as a robust and efcient framework has been studied widely for robot learning from *** DMPs framework mainly focuses on the movement learning in Cartesian or joint space,and can’t properly represent end-efector *** this paper,we present an extended DMPs framework(EDMPs)both in Cartesian space and 2-Dimensional(2D)sphere manifold for Quaternion-based orientation learning and *** mixture model and Gaussian mixture regression(GMM-GMR)are adopted as the initialization phase of EDMPs to handle multi-demonstrations and obtain their mean and ***,some evaluation indicators including reachability and similarity are defned to characterize the learning and generalization abilities of ***,a real-world experiment was conducted with human demonstrations,the endpoint poses of human arm were recorded and successfully transferred from human to the *** experimental results show that the absolute errors of the Cartesian and Riemannian space skills are less than 3.5 mm and 1.0°,*** Pearson’s correlation coefcients of the Cartesian and Riemannian space skills are mostly greater than *** developed EDMPs exhibits superior reachability and similarity for the multi-space skills’learning and *** research proposes a fused framework with EDMPs and GMM-GMR which has sufcient capability to handle the multi-space skills in multi-demonstrations.

关键词： Learning from demonstration Dynamic movement primitives 2D sphere manifold Gaussian mixture model Gaussian mixture regression Quaternion-based orientation