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Stabilization of Nonuniform Euler-Bernoulli Beam with Locally Distributed Feedbacks

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Acta Mathematicae Applicatae Sinica 2012年第1期28卷 131-138页

作者： Xian-bing cao Qing-xu YAN Department of Mathematics School of SciencesBeijing Technology and Business UniversityBeijing 100048China Information Engineering School China Geosciences UniversityBeijing 100083China

In this article, we study the stabilization problem of a nonuniform Euler-Bernoulli beam with locally distributed feedbacks. Firstly, using the semi-group theory, we establish the well-posedness of the associated closed loop system. Then by proving the uniqueness of the solution of a related ordinary differential equations, we derive the asymptotic stability of the closed loop system. Finally, by means of the piecewise frequency domain multiplier method, we prove that the corresponding closed loop system can be exponentially stabilized by only one of the two distributed feedback controls proposed in this paper.

关键词： nonuniform Euler-Bernoulli beam linear locally distributed feedback control linear semigroup,exponential stability piecewise multiplier method

Perturbation of the Moore–Penrose Metric Generalized Inverse in Reflexive Strictly Convex Banach Spaces

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Acta Mathematica Sinica,English Series 2016年第6期32卷 725-735页

作者： Jian bing cao Wan Qin ZHANG Postdoctoral Research Base He'nan Institute of Science and Technology Postdoctoral Research Station of Physics He'nan Normal University Department of Mathematics He'nan Institute of Science and Technology

Let X, Y be reflexive strictly convex Banach spaces, let T, δT ： X → Y be bounded linear operators with closed range R（T）. Put T= T ＋ δT. In this paper, by using the concept of quasiadditivity and the so called generalized Neumman lemma, we will give some error estimates of the bounds of ｜｜T^M｜｜. By using a relation between the concepts of the reduced minimum module and the gap of two subspaces, some new existence characterization of the Moore-Penrose metric generalized inverse T^M of the perturbed operator T will be also given.

关键词： Metric generalized inverse perturbation reflexive strictly convex Banach space

A comprehensive review on microchannel heat sinks for electronics cooling

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International Journal of Extreme Manufacturing 2024年第2期6卷 133-162页

作者： Zhi-Qiang Yu Mo-Tong Li bing-Yang cao Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084People’s Republic of China

The heat generation of electronic devices is increasing dramatically,which causes a serious bottleneck in the thermal management of electronics,and overheating will result in performance deterioration and even device *** the development of micro-machining technologies,the microchannel heat sink(MCHS)has become one of the best ways to remove the considerable amount of heat generated by high-power *** has the advantages of large specific surface area,small size,coolant saving and high heat transfer *** paper comprehensively takes an overview of the research progress in MCHSs and generalizes the hotspots and bottlenecks of this *** heat transfer mechanisms and performances of different channel structures,coolants,channel materials and some other influencing factors are ***,this paper classifies the heat transfer enhancement technology and reviews the related studies on both the single-phase and phase-change flow and heat *** comprehensive review is expected to provide a theoretical reference and technical guidance for further research and application of MCHSs in the future.

关键词： microchannel heat sink thermal management of electronics microscale heat transfer heat transfer enhancement

Phonon relaxation and heat conduction in one-dimensional Fermi Pasta Ulam β lattices by molecular dynamics simulations

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Chinese Physics B 2012年第1期21卷 279-283页

作者： Hou Quan-Wen cao bing-Yang Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China Key Laboratory of Space Applied Physics and Chemistry of Ministry of Education Department of Applied PhysicsNorthwestern Polytechnical UniversityXi’an 710072China

The phonon relaxation and heat conduction in one-dimensional Fermi Pasta-Ulam （FPU） β lattices are studied by using molecular dynamics simulations. The phonon relaxation rate, which dominates the length dependence of the FPU β lattice, is first calculated from the energy autoeorrelation function for different modes at various temperatures through equilibrium molecular dynamics simulations. We find that the relaxation rate as a function of wave number k is proportional to k^1.688, which leads to a N^0.41 divergence of the thermal conductivity in the framework of Green-Kubo relation. This is also in good agreement with the data obtained by non-equilibrium molecular dynamics simulations which estimate the length dependence exponent of the thermal conductivity as 0.415. Our results confirm the N^2/5 divergence in one-dimensional FPU β lattices. The effects of the heat flux on the thermal conductivity are also studied by imposing different temperature differences on the two ends of the lattices. We find that the thermal conductivity is insensitive to the heat flux under our simulation conditions. It implies that the linear response theory is applicable towards the heat conduction in one-dimensional FPU β lattices.

关键词： thermal conductivity phonon relaxation low-dimensional heat conduction FermiPasta Ulam (FPU) Key Laboratory of Space Applied Physics and Chemistry of Ministry of Education Department of Applied Physics Northwestern Polytechnical University Xi'an 710072 China lattice

Global Optimization Method for Linear Multiplicative Programming

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Acta Mathematicae Applicatae Sinica 2015年第2期31卷 325-334页

作者： Xue-gang ZHOU bing-yuan cao Kun WU School of Mathematics and Information Science Key Laboratory of Mathematics and Interdisciplinary Sciences of Guangdong Higher Education Institutes Guangzhou University Department of Applied Mathematics Guangdong University of Finance School of Mathematical Science and Computing Technology Center South University

In this paper, a new global algorithm is presented to globally solve the linear multiplicative programming（LMP）. The problem（LMP） is firstly converted into an equivalent programming problem（LMP（H））by introducing p auxiliary variables. Then by exploiting structure of（LMP（H））, a linear relaxation programming（LP（H）） of（LMP（H）） is obtained with a problem（LMP） reduced to a sequence of linear programming problems. The algorithm is used to compute the lower bounds called the branch and bound search by solving linear relaxation programming problems（LP（H））. The proposed algorithm is proven that it is convergent to the global minimum through the solutions of a series of linear programming problems. Some examples are given to illustrate the feasibility of the proposed algorithm.

关键词： linear multiplicative programming global optimization linear programming branch and bound

Fabrication of high-performance PVA/PAN composite pervaporation membranes crosslinked by PMDA for wastewater desalination

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Petroleum Science 2018年第1期15卷 146-156页

作者： Rui Zhang Xiaoying Xu bing cao Pei Li College of Materials Science and Engineering Beijing University of Chemical Technology

The pyromellitic dianhydride（PMDA） crosslinked poly（vinyl alcohol）（PVA） was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite membranes have high application value in industrial wastewater treatment. By varying the membrane fabrication parameters including the weight percent（wt%） of the PMDA, the crosslink temperature and duration, membrane with the best desalination performance was obtained. The composite membrane with a 2-lm-thick PVA selective layer containing 20 wt% of PMDA and being crosslinked at 100 °C for 2 h showed the highest Na Cl rejection of 99.98% with a water flux of 32.26 L/（m^2 h）at 70 °C using the 35,000 ppm Na Cl aqueous solution as feed. FTIR spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron microscope have been used to characterize the structures and properties of both the crosslinked PVA dense films and PVA/PAN composite membranes. The effects of the concentrations of PMDA,the crosslinking time and temperature to the membrane water contact angle, swelling degree, salt rejection and water flux were systematically studied.

关键词： Pervaporation - Desalination Crosslinked PVA Composite membranes Wastewater treatment

Electrochemical Degradation of o-Chloronitrobenzene by Three-dimensional Electrodes

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Chemical Research in Chinese Universities 2012年第5期28卷 891-896页

作者： MENG Qing-han WANG Jing LIU Ling cao bing College of Materials Science and Engineering Beijing University of Chemical TechnologyBeo'ing 100029P.R.China

Degradation of o-chloronitrobenzene wastewater was experimentally investigated at a three-dimensional electrode（TDE） with granular activated carbon as the particle electrode, graphite as the anode, and stainless steel plate as the cathode. The kinetic model of o-chloronitrobenzene degradation was studied, and the effects of pH, electrolysis time, particle electrode, electrolyte concentration, and initial concentration of the solution on degradation efficiency were investigated to determine the optimal operating conditions. The degradation of o-chloronitrobenzene by oxidation at the TDE was monitored by chemical oxygen demand（COD） measurements, UV-Vis absorption, and high performance liquid chromatography（HPLC）. COD degradation by electrochemical degradation followed pseudo-first order kinetics with respect to the concentration of o-chloronitrobenzene solutions. Optimal reaction conditions included 15 g of activated carbon as the particle electrode, 400 mg/L o-chloronitrobenzene solution containing 0.10 mol/L Na2SO4, pH=3, and 60 min of electrolysis. The UV-Vis absorption spectra and HPLC results illustrate that the benzene ring in o-chloronitrobenzene was rapidly broken down to form aliphatic substances through electrochemical degradation. COD degradation was approximately 98.5% at optimal conditions.

关键词： Three-dimensional electrode Electrochemical oxidation o-Chloronitrobenzene

Continuous generating grinding method for beveloid gears and analysis of grinding characteristics

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Advances in Manufacturing 2022年第3期10卷 459-478页

作者： bing cao Guo-Long Li Alessandro Fortunato Heng-Xin Ni College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400030People's Republic of China State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing 400044People's Republic of China Department of Industrial Engineering(DIN) Alma Mater StudiorumUniversity of BolognaViale Risorgimento 2Bologna 40136Italy

Continuous generating grinding has become an important gear processing method owing to its high efficiency and *** this study,an adaptive design model is proposed for the continuous generation of beveloid gears in common gear grinding *** on this model,a method for determining the installation position and grinding kinematics is developed alongside an analytical meshing model for grinding contact trace and derivation of key grinding *** combining these aspects,a general mathematical model for the continuous generation of beveloid gears is presented,comprising the entire grinding process from worm wheel dressing to the evaluation of grinding *** effects of the worm and dressing wheel parameters on the grinding deviation were analysed,facilitating the development of an approach to improve the grinding *** presented procedure represents a novel design method for the continuous generation of beveloid gears in common gear grinding machines,facilitating the appropriate selection of worm and dressing wheel parameters.

关键词： Beveloid gears Continuous generating grinding Meshing model Kinematics model

Design and synthesis of novel antifungal triazole derivatives with good activity and water solubility

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Chinese Chemical Letters 2013年第4期24卷 303-306页

作者： Xu-Feng cao Wen-Jing Chu Yong-bing cao Yu-She Yang State Key Laboratory of Drug Research Shanghai Institute of Materia MedicaChinese Academy of Sciences School of Pharmacy Second Military Medical University

In order to find novel antifungal agents with good activity and aqueous solubility, a series of SYN-2869 analogues containing a pyridine ring were synthesized and evaluated for their in vitro antifungal activity and water solubility. The results indicated that some compounds showed potent activity against six pathogenic fungi. In particular, the analogue 17a having an isobutyl substitution on the triazolone exhibited significant broad spectrum antifungal activity. In addition, the water solubility of compound l？a was sufficiently improved over SYN-2869.

关键词： SynthesisAntifungalSYN-2869 analoguesTriazoleWater solubility