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Applied Mathematics and Mechanics(English Edition) 2016年第6期37卷 683-694页

作者： Bo YANG Weiqiu chen Haojiang DING Department of Civil Engineering Zhejiang Sci-Tech University State Key Laboratory of CAD & CG Zhejiang University Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Soft Matter Research CenterDepartment of Engineering MechanicsZhejiang UniversityYuquan Campus Department of Civil Engineering Zhejiang University

The problem of a transversely isotropic functionally graded material （FGM） plate welded with a circular inclusion is considered. The analysis starts with the general- ized England-Spencer plate theory for transversely isotropic FGM plates, which expresses a three-dimensional （3D） general solution in terms of four analytic functions. Several analytical solutions are then obtained for an infinite FGM plate welded with a circular inclusion and subjected to the loads at infinity. Three different cases are considered, i.e., a rigid circular inclusion fixed in the space, a rigid circular inclusion rotating about the x-, y-, and z-axes, and an elastic circular inclusion with different material constants from the plate itself. The static responses of the plate and/or the inclusion are investigated through numerical examples.

关键词： plate functionally graded material (FGM) welded circular inclusion,analytical solution

Analysis of Heat Dissipation in LED with Various Adhesives

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Journal of Thermal Science 2011年第3期20卷 254-259页

作者： Zi-Gui Huang Zheng-Yu chen Department of Mechanical Design Engineering National Formosa University Huwei Yun-lin Taiwan China

Light-emitting diodes (LEDs) are semiconducting, light producing units, with the advantages of small size, long life, low voltage, reduced energy consumption, and high vibration resistance. Unfortunately, most LED output power is converted into heat, with little converted into optical energy. If the heat is not transferred outward from the unit, the LED will overheat and its light emission efficiency, stability, and lifespan will be reduced. Improving LED heat dissipation has become a hot topic. This paper used the finite element method to discuss the temperature change in LED heat sources, using epoxy and Al2O3 adhesives with varying heat transfer coefficients.

关键词： LED heat dissipation finite element method heat transfer coefficient adhesive

Numerical Investigation of the Thermal Response to Skin Tissue during Laser Lipolysis

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Journal of Thermal Science 2018年第5期27卷 470-478页

作者： chen Bin ZHANG Yue LI Dong State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University

Laser lipolysis can effectively treat obesity and its associated diseases, such as hypertension, fatty liver, and hyperlipidemia. However, currently available invasive laser lipolysis, which transmits laser to a fiber-optic catheter inserted into the subcutaneous tissue for irradiation through an incision, may cause hematomas, infections, and empyrosis. The current study presents a novel, noninvasive approach for laser lipolysis, which directly irradiates the intact skin surface without an incision and preferentially targets adipose tissue at the near-infrared band. High laser energy is necessary to damage adipocytes; however, this may carbonate and burn the dermis. Therefore, the introduction of skin cooling is essential to avoid unwanted hyperthermal injury and improve the threshold of radiant exposure. In the current study, we investigated a novel noninvasive approach assisted with skin cooling by establishing a homogeneous multi-layer skin model. In this method, light propagation in the skin was simulated by using the Monte Carlo method. Skin cooling was employed before laser irradiation to protect the epidermis from thermal damage, which was treated as a boundary condition based on Newton's law. The numerical results showed that the photons were deposited in the adipose layer more than in the other layers. Laser can effectively destroy adipose tissue at an energy density of >200 J/cm^2 at 1210 nm wavelength, whereas at least 300 J/cm^2 is required at 1064 nm to achieve the same effect. In this experiment, at >5 s pulse width, the selectivity of adipose was not obvious. Moreover, the results indicated that 60 ms R134a or R404a spray can effectively reduce the temperature of the epidermis. R404a exhibited a stronger cooling effect than R134a. Cold air cooling at -10 °C for 10 s could effectively decrease the skin temperature, and deeper cooling could be achieved by cold air cooling compared with cryogen spray cooling.

关键词： laser lipolysis Nd:YAG laser multi-layer skin model skin cooling

Planet host stars in open clusters

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Science China(Physics,Mechanics & Astronomy) 2015年第3期58卷 96-101页

作者： YANG XiaoLing chen YuQin ZHAO Gang Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences

We have compiled a list of all planet host star candidates reported in the literature,which are likely to be cluster members,and we checked their memberships by the spatial location,radial velocity,proper motion and photometric *** found that only six stars,BD-13 2130,HD 28305,Kepler-66,Kepler-67,Pr0201 and Pr0211,are planet orbiting stars in open clusters to *** stars,HD 70573 and HD 89744,belong to moving groups and one star,TYC 8975-2606-1,may not be a planet host star,while three stars,HD 16175,HD 46375 and HD 108874 are not members of open *** note that all these six planetary systems in the stellar cluster environment are younger than^1 Gyr,which might indicate that the planetary system in open cluster can not survive for a long time,and we speculate that close stellar encounters between member stars in open cluster can potentially destroy,or at least strongly affect,the presence of planetary systems.

关键词： extrasolar planets planetary survival open cluster

Crystallization of self-propelled particles on a spherical substrate

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Applied Mathematics and Mechanics(English Edition) 2019年第10期40卷 1387-1398页

作者： Yan FANG chen WANG Hongyuan JIANG CAS Key Laboratory of Mechanical Behavior and Design of Materials Hefei National Laboratory for Physical Science at the Microscale Department of Modern Mechanics University of Science and Technology of China

In this paper, we investigate the self-propelled particles confined on a spherical substrate and explore the structural and dynamic properties of self-propelled particles by controlling the packing fraction and activity. We find that these self-propelled particles freeze into the crystal with the increase in the packing fraction. We observe the pattern evolution of inevitable topological defects due to the geometric constraints of the spherical substrate. During the process of freezing, there is a transition from twelve isolated grain boundaries to the uniform distribution of defects with the increase in the self-propelled velocity. Finally, we establish a phase diagram of the freezing process. These results may deepen our understanding of active particles in complex and crowded environments.

关键词： self-prop elled particle freezing process geometric constraint defect

A fast and practical method to pack spheres for mesh generation

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Acta Mechanica Sinica 2008年第4期24卷 439-447页

作者： Jianfei Liu Shuixiang Li Yongqiang chen LTCS College of EngineeringPeking University Beijing 100871 China

Sphere packing is an attractive way to generate high quality mesh. Several algorithms have been proposed in this topic, however these algorithms are not sufficiently fast for large scale problems. The paper presents an efficient sphere packing algorithm which is much faster and appears to be the most practical among all sphere packing methods presented so far for mesh generation. The algorithm packs spheres inside a domain using advancing front method. High efficiency has resulted from a concept of 4R measure, which localizes all the computations involved in the whole sphere packing process.

关键词： Sphere packing· Front Sheltering operation ·Mesh sizing function Mesh generation

Stripping of uranium from an ionic liquid medium by TOPO-modified supercritical carbon dioxide

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Science China Chemistry 2015年第3期58卷 545-550页

作者： Jing Fu Qingde chen Xinghai Shen Beijing National Laboratory for Molecular Sciences (BNLMS) Fundamental Science on Radiochemistry and Radiation Chemistry LaboratoryCollege of Chemistry and Molecular Engineering Peking University

UO2＋, which is extracted from the aqueous phase into the 1-ethyl-3-methylimidazolium bis（trifluoromethylsulfonyl）imide（C2mim NTf2） ionic liquid ph^ase with octyl（phenyl）-N,N-diisobutylcarbamoylmethylphosphine oxide（CMPO）, can be stripped by supercritical CO2. Trioctylphosphine oxide（TOPO）, the modifier added to the supercritical CO2 phase, enhances the stripping efficiency by up to 99%.

关键词： UO2^2+ supercritical CO2 stripping CMPO ionic liquids

Forward Dynamics Analysis of the 6-PUS Mechanism Based on Platform-Legs Composite Simulation

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Chinese Journal of Mechanical Engineering 2009年第4期22卷 496-504页

作者： WANG Hao chen Genliang LIN Zhongqin Key Laboratory of Auto-body Engineering in Shanghai City Shanghai Jiao Tong University Shanghai 200240 China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai 200240 China

The dynamics analysis plays an important role for the control, simulation and optimization of the parallel manipulators. Normally, the Stewart type manipulators have a platform and several legs. The inverse dynamics can be solved efficiently by taking the advantage of such structural characteristics. However, for the forward dynamics analysis, this structural decomposition still faces challenges from both modeling and computation. In this paper, an efficient approach is proposed for the forward dynamics of the 6-PUS manipulator based on the platform-legs composite simulation. By composite method, the dynamics modeling of the parallel manipulator is separated into the forward dynamics of the platform and the kineto-statics of the legs. The global simulation model can be constructed by connecting the predefined platform model and leg models according to the manipulator＇s topology. Thus, the global simulation can be decomposed into the independent calculations of purely algebraic equations and ordinary differential equations （ODEs）, the computational cost can be reduced and the stability of the simulation can be improved. For the purpose of solving the manipulator＇s forward dynamics accurately, the algebraic-loop problem is discussed and a closed form algorithm is proposed. A numerical example of the 6-PUS manipulator is given to demonstrate the effectiveness of the proposed approach. The example results show that the modeling efficiency can be improved and the simulation stability can be ensured for decomposing the system equations into purely algebraic equations and ODEs.

关键词： forward dynamics Gough-Stewart platform simulation

Tunable Curie temperature and magnetocaloric effect of FeCrMoCBYNi bulk metallic glass with different crystallized phases

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Journal of Rare Earths 2019年第4期37卷 404-409页

作者： Yuanbin Lv Qingjun chen Youlin Huang School of Materials Science and Engineering Nanchang Hangkong University

The investigation on Curie temperature and magnetocaloric effect of the FeCrMoCBYNi bulk metallic glass(BMG) with different crystallized phases was carried out by XRD,TEM and PPMS. The experimental results show that the Curie temperature(T_c) of Fe_(45)Cr_(15)Mo_(14)C_(15)B_6 Y_2 Ni_3 BMG with different annealing condition reaches a highest value of 95 K. The value of magnetic entropy change △S_M(T) of Sample 3 reaches a maxima of 0.48 J/(kg·K) at Tc temperature, which result from the interaction among the precipitated phases of(Fe,Cr)_(23)(C,B)_6, Fe_3 Mo_3 C and residual amorphous phase. Based on the experiment results, it can be obtained that the Curie temperature, magnetocaloric effect can reach their optimal value at low temperature, when the content of amorphous phase and precipitated phases type run up to certain value. The magnetic properties of Sample 1 with full amorphous phase and Sample 4 with full crystalline phase will both decrease.

关键词： Bulk metallic glass Crystallization Curie temperature Magnetocaloric effect Rare earths

Thermodynamic Analysis and Optimization of an Irreversible Maisotsenko-Diesel Cycle

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Journal of Thermal Science 2019年第4期28卷 659-668页

作者： ZHU Fuli chen Lingen WANG Wenhua College of Power Engineering Naval University of EngineeringWuhan 430033China Institute of Thermal Science and Power Engineering Wuhan Institute of TechnologyWuhan 430205China School of Mechanical & Electrical Engineering Wuhan Institute of TechnologyWuhan 430205China

So far,Maisotsenko cycle has been applied to many fields such as heating ventilation and air-conditioning,power industry,chemical production,and so on.A lot of researches about classical thermodynamic analyses of Maisotsenko cycle have been made.A new cycle model of combined Diesel and Maisotsenko cycles considering heat transfer loss(HTL),piston friction loss(PFL)and internal irreversible loss(IIL)was proposed in this *** using the finite time thermodynamic(FTT)theory,the power and efficiency performances of the Maisotsenko-Diesel cycle(MDC)were *** of mass flow rate(MFR)of water injection in the Maisotsenko air saturator(MAS)and the other parameters related to the design of Diesel engine on the optimal cycle performances were ***,it was testified that irreversible MDC was superior than conventional irreversible Diesel cycle in both power output and thermal *** results can expand the application of Maisotsenko cycle(M-cycle)and provide some theoretical guidelines for the practical devices.

关键词： Maisotsenko-Diesel cycle finite-time thermodynamics power output thermal efficiency performance optimization