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Large electrocaloric effect in BaTiO_3 based multilayer ceramic capacitors

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Science China(Technological Sciences) 2016年第7期59卷 1054-1058页

作者： LU Biao wen XinHua TANG ZhenHua liang Bo TAO Tao XIE ZhiWei ZHANG TianFu TANG XinGui XIANG Yong liao Jie LU ShengGuo Guangdong Provincial Key Laboratory of Functional Soft Matter School of Materials and Energy Guangdong University of Technology Guangzhou 510006 China School of Physics and Electronics Guangdong University of Technology Guangzhou 510006 China EYANG Technology Development Co. Ltd. Shenzhen 518057 China

The electrocaloric effect(ECE) of multilayer ceramic capacitor(MLCC) of Y5 V type was directly measured via a differential scanning calorimetry(DSC) method and a reference resistor was used to calibrate the heat flow due to the heat dissipation. The results are compared with those calculated from Maxwell relations by using the polarization data obtained from the polarization–electric field hysteresis loops. The direct method shows a larger ECE temperature change, which is accounted for the situation approaches an ideal condition. For the indirect method using Maxwell relations, only the polarization projection along the electric field was taken into account, which will be less than the randomly distributed real polarizations that contribute to the ECE. The MLCCs exhibit a broad peak of ECE around 80 C, which will be favorite for the practical ECE cooling devices.

关键词： multilayer ceramic capacitors maxwell relations electrocaloric effect polarization–electric field hysteresis loop differential scanning calorimetry

Construction and Count of 1-Resilient Rotation Symmetric Boolean Functions on pr Variables

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Chinese Journal of Electronics 2014年第4期23卷 816-820页

作者： DU Jiao PANG Shanqi wen Qiaoyan liao Xin College of Mathematics and Information Science Henan Normal University State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications College of Information Science and Engineering Hunan University

Construction and count of 1-resilient Rotation symmetric Boolean functions(RSBFs) on p r variables are demonstrated. It is proved that constructions of1-resilient RSBFs on p r variables are equivalent to solving an equation system. An accurate enumeration formula of all 1-resilient RSBFs on p r variables is also proposed. Some examples are given, and the exact numbers of 1-resilient RSBFs on 8 and 9 variables are obtained respectively.

关键词： Cryptography Rotation symmetric Support table Correlation-immune Resilient functions

An improved CFD model of gas flow and particle interception in a fiber material

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Chinese Journal of Chemical Engineering 2017年第3期25卷 264-273页

作者： Zhiwei Sun Jianhui wen Xiao Luo wen Du Zhiwu liang Kaiyun Fu Technology Center of China Tobacco Hunan Industrial Co. Ltd. Joint International Center for CO2 Capture and Storage (iCCS) Hunan Provincial Key Laboratory for Cost-effective Utilization of Fossil Fuel Aimed at Reducing CO2 EmissionsCollege of Chemistry and Chemical EngineeringHunan University

An improved CFD model of gas flow and particle interception in a fiber material which fiber size is Y-shape was developed in this work. The porous medium model was used to build the model of the whole size of fiber filter medium. Mixture model was adopted. The algorithm of particle interception in the whole size of fiber filter medium was derived and UDF(User Defined Function) that described kinds of particle filtering mechanisms in filter fibrous media was added to the Fluent default conservation equation as source term for simulation. The inertial resistance of the filter was taken into consideration, which provided a more precise measurement of the smoke flow and the particle interception in the filter under higher smoke speed conditions. The commercial software, Fluent 6.3, was used to simulate the smoke flow and particle interception in the filter in a single suction. The velocity and pressure profiles of smoke or nicotine particle in the filter, as well as nicotine particle volume fraction profile were well simulated. Finally, the comparisons of nicotine particle filtration efficiency between Fluent simulation results in this work and experimental results, as well as the model prediction in the literature were made to validate the simulation model. The comparisons showed that the particle entrapment model from simulation results was in good agreement with that from the experimental results. In addition, the Fluent simulation results are closer to reality both at the beginning and the end of the smoke process comparing with the model predicted results in the literature.

关键词： Numerical simulation Y-shape fiber Particle interception Flow field distribution Filtration efficiency UDF

New advances in small molecule hole-transporting materials for perovskite solar cells

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Chinese Chemical Letters 2016年第8期27卷 1293-1303,1469页

作者： Ya-Kun Wang Zuo-Quan Jiang liang-Sheng liao Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices Institute of Functional Nano & Soft Materials (FUNSOM) Soochow University

Organic π-functional molecules are the foundation and basic component of organic optoelectronic *** example,for ideal carrier transporting materials,extended π-conjugation and ordered π-πstacking are necessary to enhance the charge mobility and achieve desirable *** a promising way to convert sunlight into electricity,organometal halide perovskite solar cells（PSCs） have captured a lot of attention due to its predominant merits especially in the aspect of remarkable photovoltaic performance and much potentially low production *** conventional planar PSC structure,hole-transporting layer which typically consists of organic π-functional materials plays a key role in suppressing holeelectron pair recombination,promoting charge transporting and ensuring ohmic contact of back *** the key roles of HTMs and its soaring progress in recent years,here,we will summarize recent progress in small organic π-functional materials from its diverse functions in ***,aiming to further promote the development of organic π-functional molecules and HTMs,a promising direction toward highly efficient HTMs will also be discussed.

关键词： Perovskite solar cell Photovoltaic device Small molecule Conjugated structure Hole-transporting material

Orbital evolution of a planet with tidal dissipation in a restricted three-body system

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Research in Astronomy and Astrophysics 2019年第9期19卷 79-96页

作者： wen-Lei Wang Xue-Qing Xu Xin-Hao liao Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai200030China Key Laboratory of Planetary Sciences Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai200030China University of Chinese Academy of Sciences Beijing100049China

The angle between planetary spin and the normal direction of an orbital plane is supposed to reveal a range of information about the associated planetary formation and evolution. Since the orbit’s eccentricity and inclination oscillate periodically in a hierarchical triple body and tidal friction makes the spin parallel to the normal orientation of the orbital plane with a short timescale in an isolated binary system, we focus on the comprehensive effect of third body perturbation and tidal mechanism on the angle. Firstly, we extend the Hut tidal model(1981) to the general spatial case, adopting the equilibrium tide and weak friction hypothesis with constant delay time, which is suitable for arbitrary eccentricity and any angle ? between the planetary spin and normal orientation of the orbital plane. Furthermore, under the constraint of angular momentum conservation, the equations of orbital and ratational motion are given. Secondly, considering the coupled effects of tidal dissipation and third body perturbation, and adopting the quadrupole approximation as the third body perturbation effect, a comprehensive model is established by this work. Finally, we find that the ultimate evolution depends on the timescales of the third body and tidal friction. When the timescale of the third body is much shorter than that of tidal friction, the angle ? will oscillate for a long time,even over the whole evolution;when the timescale of the third body is observably larger than that of the tidal friction, the system may enter stable states, with the angle ? decaying to zero ultimately, and some cases may have a stable inclination beyond the critical value of Lidov-Kozai resonance. In addition, these dynamical evolutions depend on the initial values of the orbital elements and may aid in understanding the characteristics of the orbits of exoplanets.

关键词： astrometry and celestial mechanics:celestial mechanics planet-star interactions planets and satellites:dynamical evolution and stability

Parallel Construction Heuristic Combined with Constraint Propagation for the Car Sequencing Problem

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 373-384页

作者： Xiangyang ZHANG liang GAO Long wen Zhaodong HUANG Faulty of Maritime and Transportation Ningbo UniversityNingbo 315211China State Key Lab.of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China National Traffic Management Engineering and Technology Research Centre Ningbo University Sub-center Ningbo UniversityNingbo 315211China

For the car sequencing（CS） problem, the draw-backs of the ＂sliding windows＂ technique used in the objective function have not been rectified, and no high quality initial solution has been acquired to accelerate the improvement of the solution quality. Firstly, the objective function is improved to solve the double and bias counting of violations broadly discussed. Then, a new method combining heuristic with constraint propagation is proposed which constructs initial solutions under a parallel framework. Based on constraint propagation, three filtering rules are designed to intersecting with three greedy functions, so the variable domain is narrowed in the process of the construction. The parallel framework is served to show its robustness in terms of the quality of the solution since it greatly increases the performance of obtaining the best solution. In the computational experiments, 109 instances of 3 sets from the CSPLib＇ s benchmarks are used to test the performance of the proposed method. Experiment results show that the proposed method outperforms others in acquiring the best-known results for 85 best-known results of 109 are obtained with only one construction. The proposed research provides an avenue to remedy the deficiencies of ＂sliding windows＂ technique and construct high quality initial solutions.

关键词： Car sequencing problem · Constraint propagation · Parallel construction heuristic · Filtering rule

Designing reduced beacon trajectory for sensor localization

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第12期8卷 1971-1982页

作者： HUANG wen-liang LI Shi-jian LIU Duo School of Computer Science Zhejiang University Hangzhou 310027 China Graduate School Zhejiang University Hangzhou 310027 China

Localization is one of the substantial issues in wireless sensor networks. The key problem for the mobile beacon localization is how to choose the appropriate beacon trajectory. However, little research has been done on it. In this paper, firstly, we deduce the number of positions for a beacon to send a packet according to the acreage of ROI (region of interest); and next we present a novel method based on virtual force to arrange the positions in arbitrary ROI; then we apply TSP (travelling salesman problem) algorithm to the positions sequence to obtain the optimal touring path, i.e. the reduced beacon trajectory. When a mobile beacon moves along the touring path, sending RF signals at every position, the sensors in ROI can work out their position with trilateration. Experimental results demonstrate that the localization method, based on the beacon reduced path, is efficient and has flexible accuracy.

关键词： Sensor network Sensor localization Mobile beacon Virtual force

Effect of near-fault earthquake on bridges:lessons learned from Chi-Chi earthquake

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Earthquake Engineering and Engineering Vibration 2002年第1期1卷 86-93页

作者： Chin-Hsiung Loh wen-I liao Juin-Fu Chai Department of Civil Engineering Taiwan Universityand Center for Research on Earthquake EngineeringChinese Taipei Professor Center for Research on Earthquake Engineering Chinese Taipei Associate Research Fellow

The objective of this paper is to describe the lessons learned and actions that have been taken related to the seismic design of bridge structures after the Chi-Chi,Taiwan *** variable near-fault ground motion data was collected from the rupture of Chelungpu fault during the Chi-Chi earthquake,allowing the seismic response of bridge structures subjected to these near-fault ground motions to be carefully *** study the near-fault ground motion effect on bridge seismic design codes,a two-level seismic design of bridge structures was developed and *** design code reflects the near-fault factors in the seismic design ***,a risk assessment methodology,based on bridge vulnerability,is also developed to assist in decisions for reducing seismic risk due to failure of bridges.

关键词： Chi-Chi earthquake near-fault bridge seismic design risk assessment

MRI image segmentation based on fast kernel clustering analysis

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Frontiers of Electrical and Electronic Engineering in China 2011年第2期6卷 363-373页

作者： liang liao Yanning ZHANG Shaanxi Provincial Key Laboratory of Speech and Image Information Processing(SAIIP) School of Computer ScienceNorthwestern Polytechnical UniversityXi’an 710129China School of Electric and Information Engineering Zhongyuan University of TechnologyZhengzhou 450007China

Kernel-based clustering is supposed to provide a better analysis tool for pattern classification,which implicitly maps input samples to a highdimensional space for improving pattern *** this implicit space map,the kernel trick is believed to elegantly tackle the problem of“curse of dimensionality”,which has actually been more challenging for kernel-based clustering in terms of computational complexity and classification accuracy,which traditional kernelized algorithms cannot effectively deal *** this paper,we propose a novel kernel clustering algorithm,called KFCM-III,for this problem by replacing the traditional isotropic Gaussian kernel with the anisotropic kernel formulated by Mahalanobis ***,a reduced-set represented kernelized center has been employed for reducing the computational complexity of KFCM-I algorithm and circumventing the model deficiency of KFCM-II *** proposed KFCMIII has been evaluated for segmenting magnetic resonance imaging(MRI)*** this task,an image intensity inhomogeneity correction is employed during image segmentation *** a scheme called preclassification,the proposed intensity correction scheme could further speed up image *** experimental results on public image data show the superiorities of KFCM-III.

关键词： kernel-based clustering dimensionality reduction speeding-up scheme magnetic resonance imaging(MRI)image segmentation intensity inhomogeneity correction