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The refined theory of transversely isotropic piezoelectric rectangular beams

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science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 473-486页

作者： gao yang1 & {2. minzhong2.1. college of science, china agricultural University, Beijing 100083, china 2. State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engi- neering science, Peking University, Beijing 100871, china 1. college of science China Agricultural University Beijing 100083 China 2. State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering science Peking University Beijing 100871 China

The problem of deducing one-dimensional theory from two-dimensional theory for a transversely isotropic piezoelectric rectangular beam is investigated. Based on the piezoelasticity theory, the refined theory of piezoelectric beams is derived by using the general solution of transversely isotropic piezoelasticity and Lur'e method without ad hoc assumptions. Based on the refined theory of piezoelectric beams, the exact equations for the beams without transverse surface loadings are derived, which consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beams under transverse loadings are derived directly from the refined beam theory. As a special case, the governing differential equations for transversely isotropic elastic beams are obtained from the corresponding equations of piezoelectric beams. To illustrate the application of the beam theory developed, a uniformly loaded and simply supported piezoelectric beam is examined.

关键词： rectangular beams, the refined theory, piezoelectric, transversely isotropic.

The refined theory of deep rectangular beams for symmetrical deformation

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science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 919-925页

作者： gao yang1 & wang minzhong2.1 college of science, china {2. University, Beijing 100083, china 2.State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering, Peking University, Beijing 100871, china college of science China Agricultural University Beijing 100083 China State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering Peking University Beijing 100871 China

Based on elasticity theory, various one-dimensional equations for symmetrical deformation have been deduced systematically and directly from the two-dimensional theory of deep rectangular beams by using the Papkovich-Neuber solution and the Lur'e method without ad hoc assumptions, and they construct the refined theory of beams for symmetrical deformation. It is shown that the displacements and stresses of the beam can be represented by the transverse normal strain and displacement of the mid-plane. In the case of homogeneous boundary conditions, the exact solutions for the beam are derived, and the exact equations consist of two governing differential equations: the second-order equation and the transcendental equation. In the case of non-homogeneous boundary conditions, the approximate governing differential equations and solutions for the beam under normal loadings only and shear loadings only are derived directly from the refined beam theory, respectively, and the correctness of the stress assumptions in classic extension or compression problems is revised. Meanwhile, as an example, explicit expressions of analytical solutions are obtained for beams subjected to an exponentially distributed load along the length of beams.

关键词： deep rectangular beams the refined theory symmetrical deformation the Papkovich-Neuber solution the Lur’e method

Efficient Monolithic Perovskite/Silicon Tandem Photovoltaics

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Energy & Environmental Materials 2024年第3期7卷 268-281页

作者： Yong wang Yu wang Feng {2. Deren yang State Key Laboratory of Silicon Materials and School of Materials science and Engineering Zhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 310014China Department of Physics Chemistry and Biology(IFM)Linköping UniversityLinköping 58183Sweden

Tunable bandgaps make halide perovskites promising candidates for developing tandem solar cells(TSCs),a strategy to break the radiative limit of 33.7%for single-junction solar *** perovskites with market-dominant crystalline silicon(c-Si)is particularly attractive;simple estimates based on the bandgap matching indicate that the efficiency limit in such tandem device is as high as 46%.However,state-of-the-art perovskite/c-Si TSCs only achieve an efficiency of~32.5%,implying significant challenges and also rich *** this review,we start with the operating mechanism and efficiency limit of TSCs,followed by systematical discussions on wide-bandgap perovskite front cells,interface selective contacts,and electrical interconnection layer,as well as photon management for highly efficient perovskite/c-Si *** highlight the challenges in this field and provide our understanding of future research directions toward highly efficient and stable large-scale wide-bandgap perovskite front cells for the commercialization of perovskite/c-Si TSCs.

关键词： 2.terminal electrical interconnection perovskite/silicon tandem photovoltaics photon management wide-bandgap perovskites

Pattern phenomena in an rf discharge dusty plasma system

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science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 588-596页

作者： HUANG Feng1,2. YE Maofu2.& wang Long2.1. {2. of science, china agricultural University, Beijing 100083, china 2. Institute of Physics, Chinese Academy of sciences, Beijing 100080, china 1. college of science China Agricultural University Beijing 100083 China 2. Institute of Physics Chinese Academy of Sciences Beijing 100080 China

Various dust patterns are observed in an rf discharge dusty plasma system. According to the dust growth process from small to large in size, the formation of different dust patterns can be divided into two stages: the small-particle stage (or dust cloud stage), and the large-particle stage (or dust crystal stage). The evolution relations between different dust patterns with gas pressure changing are investigated. Dust voids, dust acoustic waves and strong turbulence modes are presented at the small-particle stage. The self-organized dust lattices and dust clusters are investigated at the large-particle stage. The static structure of a dust lattice is characterized by means of the pair correlation function. Dust clusters formed by particles with different numbers and the regular evolution of the clusters with gas pressure are also investigated. The packing sequences of dust clusters are verified through two-dimensional confined molecular dynamics simulations.

关键词： dusty plasma dust patterns

Precise orbit determination for low Earth orbit satellites using GNSS:Observations,models,and methods

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Astrodynamics 2024年第3期8卷 349-374页

作者： Xinyuan Mao Wenbing wang yang {2. Technology and Engineering Center for Space Utilization Chinese Academy of SciencesBeijing100094China University of Chinese Academy of sciences Beijing101408China

Spaceborne global navigation satellite system(GNSS)has significantly revolutionized the development of autonomous orbit determination techniques for low Earth orbit satellites for *** a state-of-the-art combination of GNSS observations and satellite dynamics,the absolute orbit determination for a single satellite reached a precision of 1 *** orbit determination(i.e.,precise baseline determination)for the dual satellites reached a precision of 1 *** paper reviews the recent advancements in GNSS products,observation processing,satellite gravitational and non-gravitational force modeling,and precise orbit determination *** key aspects have increased the precision of the orbit determination to fulfill the requirements of various scientific ***,recommendations are made to further investigate multi-GNSS combinations,satellite high-fidelity geometric models,geometric offset calibration,and comprehensive orbit determination strategies for satellite constellations.

关键词： low Earth orbit(LEO) precise orbit determination(POD) precise baseline determination(PBD) global navigation satellite system(GNSS) multi-GNSS satellite constellation

Implications of mosquito metabolism on vector competence

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Insect science 2024年第3期31卷 674-682页

作者： Li gao Wenxu yang Jingwen {2. State Key Laboratory of Genetic Engineering School of Life SciencesFudan UniversityShanghaiChina Ministry of Education Key Laboratory of Contemporary Anthropology School of Life SciencesFudan UniversityShanghaiChina

Mosquito-borne diseases(MBDs)annually kill nearly half a million *** to the lack of effective vaccines and drugs on most MBDs,disease prevention relies primarily on controlling *** huge efforts having been put into mosquito control,eco-friendly and sustainable mosquito-control strategies are still lacking and urgently *** mosquito-transmitted pathogens have lost the capacity of de novo nutrition biosynthesis,and rely on their vertebrate and invertebrate hosts for sustenance during the long-term obligate parasitism ***,a better understanding of the metabolic interactions between mosquitoes and pathogens will contribute to the discovery of novel metabolic targets or regulators that lead to reduced mosquito populations or vector *** review summarizes the current knowledge about the effects of mosquito metabolism on the transmission of multiple *** also discuss that research in this area remains to be explored to develop multiple biological prevention and control strategies for MBDs.

关键词： flaviviruses mosquito metabolism Plasmodium vector competence

Geoscience Frontiers 2.2. Annual Convention

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Geoscience Frontiers 2024年第3期15卷 484-487页

作者： Fei gao Lily wang Yongqiang {2. Geoscience Frontiers Journal CenterChina University of Geosciences(Beijing)Beijing 100083China

The 2.2. Geoscience Frontiers Annual Convention was held at Niigata,Japan during 7-12.October 2.2.,together with 2.2. IAGR Annual Convention and 2.th International Conference on Gondwana to *** grand event assembled over 2.0 participants from several countries including china,Canada,India,Italy,Japan,Netherlands,Poland,Russia,South Korea,South Africa,Sri Lanka,Vietnam,United Kingdom,and United State of America.

关键词： Canada Convention Vietnam

Boundary conditions for the bending of a piezoelectric beam

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science china(Physics,Mechanics & Astronomy) 2008年第7期51卷 847-856页

作者： gao yang1, XU SiPeng2.& ZHAO BaoSheng3 1 {2. of science, china agricultural University, Beijing 100083, china 2.{2. of Engineering, Ocean University of china, Qingdao 2.6071, china 3 School of Mechanical Engineering, University of science and Technology Liaoning, Anshan 114044, china 1. college of science China Agricultural University Beijing 100083 China 2. college of Engineering Ocean University of China Qingdao 266071 China 3. School of Mechanical Engineering University of Science and Technology Liaoning Anshan 114044 China

For beam bending in transversely isotropic piezoelectric media, the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the beam of general edge geometry and loadings. By generalizing the method developed by Gregory and Wan, a set of necessary conditions on the edge-data for the existence of a rapidly decaying solution is established. The prescribed edge-data of the beam must satisfy these conditions in order that they could generate a decaying state within the beam. When stress and mixed conditions are imposed on the beam edge, these decaying state conditions for the case of bending deformation of piezoelectric beam are derived explicitly. They are then used for the correct formulation of boundary conditions for the beam theory solution (or the interior solution). Besides, an analytical solution of elastic beam is formulated to verify validity of our boundary conditions. For the stress data, our boundary conditions coincide with those obtained in conventional forms of beam theories. More importantly, the appropriate boundary conditions with two sets of mixed edge-data are obtained for the first time.

关键词： boundary conditions beam bending piezoelectric media decaying states regular states

High-entropy rare earth stannate ceramics:Acid corrosion resistant radiative cooling materials with high atmospheric transparency window emissivity and high near-infrared solar reflectivity

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Journal of Advanced Ceramics 2024年第5期13卷 630-640页

作者： Tao Chen Yanyan He Yanyu Pan Kaixian wang minzhong Huang Liyan Xue Yazhu Li Fan {2. Yanchun Zhou Heng Chen Fujian Institute of Research on the Structure of Matter Chinese Academy of SciencesFuzhou 350002China college of Chemistry and Materials science Fujian Normal UniversityFuzhou 350117China Xiamen Institute of Rare Earth Materials Haixi InstitutesChinese Academy of SciencesXiamen 361021China Fujian science&Technology Innovation Laboratory for Optoelectronic Information of china Fuzhou 350108China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China Key Laboratory of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou 341000China School of Materials science and Engineering Zhengzhou UniversityZhengzhou 450001China

In response to the development of the concepts of“carbon neutrality”and“carbon peak”,it is critical to developing materials with high near-infrared(NIR)solar reflectivity and high emissivity in the atmospheric transparency window(ATW;8–13μm)to advance zero energy consumption radiative cooling *** regulate emission and reflection properties,a series of high-entropy rare earth stannate ceramics(HE-RE_(2.Sn_(2.O_(7):(Y_(0.2.La_(0.2.Nd_(0.2.Eu_(0.2.Gd_(0.2.)_(2.Sn_(2.O_(7),(Y_(0.2.La_(0.2.Sm_(0.2.Eu_(0.2.Lu_(0.2.)_(2.Sn_(2.O_(7),and(Y_(0.2.La_(0.2.Gd_(0.2.Yb_(0.2.Lu_(0.2.)_(2.Sn_(2.O_(7))with severe lattice distortion were prepared using a solid phase reaction followed by a pressureless sintering method for the first *** distortion is accomplished by introducing rare earth elements with different cation radii and *** as-synthesized HE-RE_(2.Sn_(2.O_(7)ceramics possess high ATW emissivity(91.38%–95.41%),high NIR solar reflectivity(92.74%–97.62.),low thermal conductivity(1.080–1.619 W·m^(−1)·K^(−1)),and excellent chemical *** the one hand,the lattice distortion intensifies the asymmetry of the structural unit to cause a notable alteration in the electric dipole moment,ultimately enlarging the ATW *** the other hand,by selecting difficult excitation elements,HE-RE_(2.Sn_(2.O_(7),which has a wide band gap(Eg),exhibits high NIR solar ***,the multi-component design can effectively enhance radiative cooling ability of HE-RE_(2.Sn_(2.O_(7)and provide a novel strategy for developing radiative cooling materials.

关键词： radiative cooling materials high-entropy ceramics(HECs) rare earth stannate(RE_(2.Sn_(2.O_(7)) high atmospheric transparency window emissivity high near-infrared(NIR)solar reflectivity