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Chinese Physics B 2024年第10期33卷 153-158页

作者： long-quan lai Zhao Li School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Electronic Engineering Chengdu Technological UniversityChengdu 611730China

Emission of matter-wave jets from a parametrically driven condensate has attracted significant experimental and theoretical attention due to the appealing visual effects and potential metrological *** this work,we investigate the collective particle emission from a Bose-Einstein condensate confined in a one-dimensional lattice with periodically modulated interparticle *** give the regimes for discrete modes,and find that the emission can be distinctly *** configuration induces a broad band,but few particles are ejected due to the interference of the matter *** further qualitatively model the emission process and demonstrate the short-time *** engineering provides a way to manipulate the propagation of particles and the corresponding dynamics of condensates in lattices,and may find application in the dynamical excitation control of other nonequilibrium problems with time-periodic driving.

关键词： Bose-Einstein condensate matter-wave jet periodic modulation

Effects of drive imbalance on the particle emission from a Bose-Einstein condensate in a one-dimensional lattice

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Chinese Physics B 2024年第3期33卷 238-243页

作者：赖龙泉李照 School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Electronic Engineering Chengdu Technological UniversityChengdu 611730China

Time-periodic driving has been an effective tool in the field of nonequilibrium quantum dynamics,which enables precise control of the particle *** investigate the collective emission of particles from a Bose-Einstein condensate in a one-dimensional lattice with periodic drives that are separate in modulation amplitudes and relative *** addition to the enhancement of particle emission,we find that amplitude imbalances lead to energy shift and band broadening,while typical relative phases may give rise to similar *** results offer insights into the specific manipulations of nonequilibrium quantum systems with tone-varying drives.

关键词： Bose-Einstein condensate particle emission periodic drive

Third-Order Magnetic Susceptibility of an Ideal Fermi Gas

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Communications in Theoretical Physics 2018年第11期69卷 619-624页

作者： long-quan lai Zhao Li Ya-Bin Yu quan-Hui Liu School for Theoretical Physics School of Physics and Electronics Hunan University

At low temperature and under weak magnetic field, non-interacting Fermi gases reveal both Pauli paramagnetism and Landau diamagnetism, and the magnitude of the diamagnetic susceptibility is 1/3 of that of the paramagnetic one. When the temperature is finite and the magnetic field is also finite, we demonstrate that the paramagnetism and diamagnetism start to deviate from the ratio 1/3. For understanding the magnetic properties of an ideal Fermi gas at quite low temperature and under quite weak magnetic field, we work out explicitly the third-order magnetic susceptibility in three cases, from intrinsic spin, orbital motion and in total. An interesting property is in third-order magnetic susceptibilities: when viewing individually, they are both diamagnetic, but in total it is paramagnetic.

关键词： Fermi gas third-order magnetic susceptibility Pauli paramagnetism Landau diamagnetism

New Method to Improve Dynamic Stiffness of Electro-hydraulic Servo Systems

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Chinese Journal of Mechanical Engineering 2013年第5期26卷 997-1005页

作者： BAI Yanhong quan long Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan University of Technology School of Electronics Information Engineering Taiyuan University of Science and Technology

Most current researches working on improving stiffness focus on the application of control *** controller in closed-loop hydraulic control system takes effect only after the controlled position is deviated,so the control action is *** dynamic performance against force disturbance and dynamic load stiffness can’t be improved evidently by advanced control *** this paper,the elementary principle of maintaining piston position unchanged under sudden external force load change by charging additional oil is *** this basis,the conception of raising dynamic stiffness of electro hydraulic position servo system by flow feedforward compensation is put *** a scheme using double servo valves to realize flow feedforward compensation is presented,in which another fast response servo valve is added to the regular electro hydraulic servo system and specially utilized to compensate the compressed oil volume caused by load impact in *** two valves are arranged in parallel to control the cylinder ***,the model of flow compensation is derived,by which the product of the amplitude and width of the valve’s pulse command signal can be *** determination rules of the amplitude and width of pulse signal are concluded by analysis and *** the proposed scheme,simulations and experiments at different positions with different force changes are *** simulation and experimental results show that the system dynamic performance against load force impact is largely improved with decreased maximal dynamic position deviation and shortened settling *** is,system dynamic load stiffness is evidently *** paper proposes a new method which can effectively improve the dynamic stiffness of electro-hydraulic servo systems.

关键词： electro-hydraulic servo system flow feedforward compensation dynamic load stiffness double-valve actuation

Mathematical Model of Hydrodynamic Torque Converter and Analytic Description of Streamline

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Chinese Journal of Mechanical Engineering 2009年第1期22卷 70-77页

作者： LIU Shiping quan long Institute of Mechatronics Engineering Taiyuan University of Technology Taiyuan 030024 China

The mathematical model of a 3-element centripetal-turbine hydrodynamic torque converter and analytic description of fluid flow inside the hydrodynamic torque converter are investigated. A new torus coordinate system is proposed so as to quantitatively describe fluid movement inside the hydrodynamic torque converter. The particle movement inside the hydrodynamic torque converter is decomposed into meridional component movement and torus component movement, and a universal meridional streamline equation is derived. According to the relationship between the converter wheel velocity polygon and its blade angle, a torus streamline differential equation is established. The universal meridional streamline equation is approximated with square polynomials. The approximation error curve is given and the percentage error is not greater than 0.86%. Considered as a function of polar angle, the blade angle cotangent of each converter wheel varies linearly with polar angle. By using integral calculus, torus streamline equations are obtained. As a result, the problem of difficult flow description of the hydrodynamic torque converter is solved and a new analytic research system is established.

关键词： hydrodynamic torque converter toms coordinate system analytic description meridional streamline equation toms streamline equation

基于O'NET半结构化访谈建构大学生职业适应力故事

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高校辅导员学刊 2025年第1期17卷 34-42,97页

作者：林振余权肖龙福建商学院传媒与会展学院福建福州350012

职业适应力是大学生转型为职场人士的关键能力,其中职业兴趣是核心要素。然而,当前对大学生职业兴趣的分析主要局限于定量评估,导致学生对自身职业兴趣的理解较为表面,甚至开始怀疑其价值。研究采用O'NET半结构化访谈,结合主题演绎驱动... 详细信息

职业适应力是大学生转型为职场人士的关键能力,其中职业兴趣是核心要素。然而,当前对大学生职业兴趣的分析主要局限于定量评估,导致学生对自身职业兴趣的理解较为表面,甚至开始怀疑其价值。研究采用O'NET半结构化访谈,结合主题演绎驱动理论,深入分析了大学生在职业适应力故事中的关注、控制、好奇、自信、合作五个维度,旨在探讨半结构化访谈如何定性地将职业兴趣代码与这五个维度的故事关联起来,并揭示其在提升大学生职业适应力方面的作用。研究结果显示,通过半结构化访谈建构的职业适应力故事,成功整合了定量与定性职业兴趣评估,这种方法不仅能帮助大学生更深入地理解自身的霍兰德职业兴趣代码,还能促使他们系统地叙述职业适应力故事,从而有效提升其职业适应力。

关键词：故事建构半结构化访谈职业适应力定性 O'NET

Preparation and characterization of single(200)-oriented TiN thin films deposited by DC magnetron reactive sputtering

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Rare Metals 2022年第4期41卷 1380-1384页

作者： Zhen-Dong Wang Zhen-quan lai Department of Physics Nanchang UniversityNanchang 330031China

Single(200)-oriented TiN thin films were deposited on quartz substrate by direct current(DC) magnetron reactive sputtering process at a wide range of substrate temperature from 200 to 600 ℃.The effects of sputtering pressure and substrate temperature on the crystalline nature,morphology,electrical and optical properties of the deposited thin films were analyzed by X-ray diffraction(XRD),atomic force microscopy(AFM),four-point resistivity test system and ultraviolet visible near-infrared(UV-Vis-NIR) spectroscopy,*** results show that single(200)-oriented TiN thin films can be obtained at a wide range of substrate temperature from 200 to 600 ℃ with the grain size increasing from 35.9 to 64.5 *** resistivity of the product is as low as95 μΩ·cm,and the value of the optical reflectance is above68 % in the near-infrared(NIR) range of 760-1500 nm.

关键词： TiN thin film DC magnetron reactive sputtering Crystal orientation Optical property

Cavitation of a Submerged Jet at the Spherical Valve Plate/Cylinder Block Interface for Axial Piston Pump

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Chinese Journal of Mechanical Engineering 2020年第5期33卷 197-211页

作者： Bin Zhao Weiwei Guo long quan College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024China Transducers and Intelligent Control System of Ministry of Education and Shanxi Province Taiyuan University of TechnologyTaiyuan 030024China The State Key Laboratory of Fluid Power&Mechatronic Systems Zhejiang UniversityHangzhou 310027China

The spherical valve plate/cylinder block pair has the advantages of strong overturning resistance and large bearing ***,the configurations of the unloading and pre-boosting triangular grooves on the spherical valve plate are different from those in the planar valve plate,resulting in special cavitation phenomenon on the spherical port plate *** order to study cavitation characteristics of spherical port plate pair,a dynamic CFD model of the piston pump including turbulence model,cavitation model and fluid compressibility is established.A detailed UDF compilation scheme is provided for modelling of the micron-sized spherical oil film mesh,which makes up for the lack of research on the meshing of the spherical oil *** this paper,using CFD simulation tools,from the perspectives of pressure field,velocity field and gas volume fraction change,a detailed analysis of the transient evolution of the submerged cavitation jet in a axial piston pump with spherical valve plate is carried *** study indicates the movement direction of the cavitation cloud cluster through the cloud image and the velocity vector direction of the observation *** sharp decrease of velocity and gas volume fraction indicates the collapse phenomenon of bubbles on the part wall *** discoveries verify the special erosion effect in case of the spherical valve plate/cylinder block *** submerged cavitation jet generated by the unloading triangular grooves distributed on the spherical valve plate not only cause denudation of the inner wall surface of the valve plate,but also cause strong impact and denudation on the lower surface of the cylinder ***,the direction of the unloading triangular groove was modified to extend the distance between it and the wall surface which can effectively alleviate the erosion effect.

关键词： Cavitation submerged jet Spherical valve plate/cylinder block pair Axial piston pump

Neodymium Organic Sulfonate Complexes: Tunable Electronegativity/Steric Hindrance and Application in Controlled Cis-1,4-polymerization of Butadiene

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Chinese Journal of Polymer Science 2019年第3期37卷 208-215页

作者： Jian-Yun He long Cui Yan-long Qi quan-quan Dai Chen-Xi Bai Key Laboratory of High-Performance Synthetic Rubber and its Composite Materials Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Rare earth catalysts possessing characteristics of cation-anion ion pair show advantages of adjusting electronegativity and steric hindrance of metal active sites, which can control the catalytic performance and stereoselectivity better than those of traditional metallocene and Ziegler-Natta catalysts in diene polymerization. In this work, a series of neodymium organic sulfonate complexes,Nd(CF_3SO_3)_3·x H_2O·y L(x, y: the coordination number; L refers to an organic electron donating ligand, such as acetylacetone(acac), isooctyl alcohol(IAOH), tributyl phosphate(TBP), etc.), have been synthesized to form the cationic active species in the presence of alkylaluminum such as Al(i-Bu)_3, AlEt_3, and Al(i-Bu)_2H, which display high activities and distinguishing cis-1,4 selectivities(up to99.9%) for the polymerization of butadiene. The microstructures, yield, molecular weight, and molecular weight distribution of the resulting polymer are well controlled by adjusting electronegativity/steric hindrance of the complexes. In addition, the kinetics, active species, and the possible process of polymerization are also discussed in this article.

关键词： Neodymium catalysts Organic sulfonate complexes Tunable electronegativity and steric hindrance Cis-1,4-polymerization Butadiene

Detecting the Position of the Moving-iron Solenoid by Non-displacement Sensor Based on Parameter Identification of Flux Linkage Characteristics

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Chinese Journal of Mechanical Engineering 2013年第6期26卷 1204-1211页

作者： WANG Xuping quan long XIONG Guangyu Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan University of Technology

Currently, most researches use signals, such as the coil current or voltage of solenoid, to identify parameters; typically, parameter identification method based on variation rate of coil current is applied for position estimation. The problem exists in these researches that the detected signals are prone to interference and difficult to obtain. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which adds a new group of secondary winding to the coil of the ordinary switching electromagnet. On the basis of electromagnetic coupling theory analysis and simulation research of the magnetic field regarding the primary and secondary winding coils, and in accordance with the fact that under PWM control mode varying core position and operating current of windings produce different characteristic of flux increment of the secondary winding. The flux increment of the electromagnet winding can be obtained by conducting time domain integration for the induced voltage signal of the extracted secondary winding, and the core position from the two-dimensional fitting curve of the operating winding current and flux-linkage characteristic quantity of solenoid are calculated. The detecting and testing system of solenoid core position is developed based on the theoretical research. The testing results show that the flux characteristic quantity of switching electromagnet magnetic circuit is able to effectively show the core position and thus to accomplish the non-displacement transducer detection of the said core position of the switching electromagnet. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which provides a new theory and method for switch solenoid to control the proportional valve.

关键词： switch solenoid flux characteristic quantity position detection non-displacement sensor