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A semi-analytical method for forced vibration analysis of cracked laminated composite beam with general boundary condition

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Journal of Ocean Engineering and science 2021年第1期6卷 40-53页

作者： sok Kim Kwanghun Kim Myongchol ri Yongsong Paek Choljun Kim Department of Information Engineering Chongjin Mine&Metal UniversityChongjin 999091Democratic People’s Republic of Korea Department of Engineering Machine Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea Institute of science Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea Department of resources Development Mechanical Engineering Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea

In this paper,a semi-analytical method for the forced vibration analysis of cracked laminated composite beam(CLCB)is *** computational model is formulated by Timoshenko beam theory and its dynamic solution is solved using the Jacobi-ritz *** boundary conditions(BCs)at both ends of the CLCB are generalized by the application of artificial elastic springs,the CLCB is separated into two elements along the crack,the flexibility coefficient of fracture theory is used to model the essential continuous condition of the connective *** the allowable displacement functions used to analyze dynamic characteristics of CLCB are expressed by classical Jacobi orthogonal polynomials in a more general *** accuracy of the proposed method is verified through the compare with results of the finite element method(software ABAQUs is used in this paper).On this basis,the parametric study for dynamic analysis characteristics of CLCB is performed to provide reference datum for engineers.

关键词： semi-analytical method Cracked laminated composite beam(CLCB) Dynamic analysis General boundary condition Numerical analysis

Bidding strategy for Coordinated Operation of Wind Power Plants and NGG-P2G Units in Electricity Market

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CsEE Journal of Power and Energy systems 2022年第1期8卷 212-224页

作者： Xiang Gao ka Wing Chan shiwei Xia Xian Zhang Guibin Wang shenzhen Polytechnic ShenzhenChina and also with the Department of Electrical Engineering The Hong Kong Polytechnic UniversityHung HomHong KongChina Department of Electrical Engineering The Hong Kong Polytechnic UniversityHung HomHong KongChina school of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China school of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen 518055China College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060China

The synergies between electricity and other energy resources could promote energy utilization efficiency in electricity *** this context,this paper proposes a bi-level stochastic optimization model for the joint operation of a coordinated wind power plant(WPP)and natural gas generating(NGG)-power to gas(P2G)suppliers participating in the day-ahead(DA)market and real-time(rT)market as well as providing real-time auxiliary *** coordinated supplier’s payoff is maximized in the upper level with consideration of the uncertainties of WPP output capacity and rT electricity price,while the social welfare of the grid is maximized in the lower *** results demonstrate the effectiveness of the proposed bidding model of the coordinated WPPs and NGG-P2G suppliers by examining its bidding behaviors and benefits with comparisons of four other bidding models.

关键词： Bi-level model bidding strategy WPP NGGP2G uncertainties

Microstructure and properties of as-cast Zr-2.5Nb-1X(X=ru,Mo,Ta and si) alloys for biomedical application

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rare Metals 2023年第10期42卷 3497-3509页

作者： Xi-Nu Tan Fei-Tao Li Yu-shun Liu ri-sheng Qiu Qing Liu Electron Microscopy Center College of Materials Science and EngineeringChongqing UniversityChongqing400044China International Joint Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing400044China TU Ilmenau Chair Materials for Electrical Engineering and ElectronicsInstitute of Materials Science and Engineering and Institute of Micro-and Nanotechnologies MacroNanoIlmenau98693Germany Department of Mechanical Engineering University of ManitobaWinnipegMBR3T 5V6Canada Key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing210009China

The micro structure and properties of as-cast Zr-2.5Nb-1X(X=ru,Mo,Ta and si) alloy are screened to explore novel biomedical zirconium alloys for magnetic resonance *** micro structure and phase transformation were characterized using X-ray diffraction(XrD),scanning electron microscope(sEM)and transmission electron microscope(TEM).Hardness test,magnetic detection and electrochemical corrosion measurements are taken to present *** results show that all alloys consist of α-Zr,β-Zr and ω-Zr.α-Zr and β-Zr mainly exist in the form of parallel and intersecting plates,and nanoscale ω-Zr is dispersed in β-Zr ***,blocky ω-Zr with needle-like α-Zr is only found in plate-free blocks of Zr-2.5Nb-1Mo/ru *** orientation relationship(Or) between α-Zr and ω-Zr follows [1120]_α//[1101]_ω and(0001)_α//([1011]_ω 011)_ω.Combining this Or with the Or between β-Zr and ω-Zr,the transformation relationship between β-Zr/ω-Zr and α-Zr is also ***-2.5Nb-1ru alloy with high corrosion potential(-0.500 V),low corrosion rate(0.949 μm·year^(-1)) and low magnetic susceptibility(92×10^(-6)) shows great potential to be a novel biomedical implant with magnetic resonance imaging *** on the experimental results,the possible relationship among alloying elements,micro structure and properties has been established in these Zr-2.5Nb-1X alloys.

关键词： Zirconium alloy Microstructure Phase transformation Electrochemical corrosion Magnetic susceptibility

structure and sequence analysis of influenza A virus nucleoprotein

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science China(Life sciences) 2009年第5期52卷 439-449页

作者： NG Andy ka-Leung sHAW Pang-Chui Molecular Biotechnology Programme Department of Biochemistry and Centre for Protein Science and Crystallography The Chi-nese University of Hong Kong

Influenza A virus nucleoprotein (NP) forms homo-oligomers and multiple copies of NP wrap around genomic rNA, along with a trimeric polymerase making up ribonucleoprotein (rNP) complex. sequence comparison of more than 2500 influenza A NP showed that this protein contains 30.1 % of polymorphic residues. NP is composed of a head and a body domain and a tail loop/ linker region. The head domain is more conserved than the body domain, as revealed from the structure-based sequence alignment. NP oligomerization is mediated by the insertion of the non-polymorphic and structurally conserved tail loop of one NP molecule to a groove of another NP. The different form of NP oligomers is due to the flexibility of the polymorphic linkers that join the tail loop to the rest of the protein. The rNA binding property of NP is known to involve the protruding element and the flexible basic loop between the head and body domains, both having high degree of primary sequence conservation. To bind rNA, NP may first capture the rNA by the flexible basic loop and then the rNA is clamped by the protruding element.

关键词： Influenza H5N1 nucleoprotein oligomerization rNA binding

Investigation into keyhole-weld pool dynamic behaviors based on HDr vision sensing of real-time K-TIG welding process through a steel/glass sandwich

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Advances in Manufacturing 2021年第1期9卷 136-144页

作者： Yan-Xin Cui Yong-Hua shi Qiang Ning Yun-Ke Chen Bao-ri Zhang Guangdong Provincial Engineering research Center for special Welding Technology and Equipment School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510640People's Republic of China

To obtain a deep insight into keyhole tungsten inert gas welding,it is necessary to observe the dynamic behavior of the weld pool and *** this study,based on the steel/glass sandwich and high dynamic range camera,a vision system is developed and the keyhole-weld pool profiles are captured during the real-time welding ***,to analyze the dynamic behavior of the weld pool and keyhole,an image processing algorithm is proposed to extract the compression depth of the weld pool and the geometric parameters of the keyhole from the captured *** considering the variations of these parameters over time,it was found that the front and rear lengths of the keyhole were dynamically adjusted internally and had opposite trends according to the real-time welding status while the length of the keyhole was in a quasi-steady *** proposed vision-based observation method lays a solid foundation for studying the weld forming process and improving keyhole tungsten inert gas welding.

关键词： Keyhole tungsten inert gas(K-TIG)welding Vision-based investigation Dynamic keyhole profile Dynamic weld pool profile

Electrochemical behavior of tungsten in(NaCl–KCl–NaF–WO_3)molten salt

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rare Metals 2013年第5期32卷 512-517页

作者： Jie Li Xin-Yu Zhang Ya-Bin Liu Yun-Gang Li ri-Ping Liu Key Laboratory of Metastable Materials science & Technology Yanshan University Key Laboratory of the Ministry of Education for Modern Metallurgy Technology College of Metallurgy & Energy Hebei United University

Abstract The electrochemical reaction mechanism and electrocrystaUization process of tungsten in the NaCl- KCl-NaF-WO3 molten salt were investigated at 973 K （700℃） by means of cyclic voltammetry, chronopotentiometry, and chronoamperometry techniques. The results show that the electrochemical reaction process of tungsten in the NaCl-KCl-NaF-WO3 molten salt system is a quasireversible process mix-controlled by ion diffusion rate and electron transport rate. Tungsten ion in this system is reduced to W（0） in two steps. The electrocrystallization process of tungsten is found to be an instantaneous, hemispheroid three-dimensional nucleation process and the tungsten ion diffusion coefficient of 2.361 × 10^-4 cm2.s^-1 is obtained at experimental conditions.

关键词： NaCl-KClNaF-WO3 Tungsten Electrochemical reduction mechanism Electrocrystallization process

An intercontinental comparison of insect seed predation between introduced and native oaks

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Integrative Zoology 2022年第2期17卷 217-230页

作者： Xin sUN Haidong LI Aibing ZHANG AnikóHIrka György CsÓka Ian s.PEArsE Marcel HOLYOAK Zhishu XIAO state Key Laboratory of Integrated Management of Pest Insects and rodents in Agriculture Institute of ZoologyChinese Academy of SciencesBeijingChina Institute of Physical science and Information Technology Anhui University111 Jiulong RoadHefeiAnhuiChina University of Chinese Academy of sciences BeijingChina College of Life sciences Capital Normal UniversityBeijingChina Department of Forest Protection NARIC Forest Research InstituteHungary U.s.Geological survey Fort Collins Science CenterFort CollinsCOUSA Department of Environmental science and Policy University of CaliforniaDavisCAUSA

Novel interactions between introduced oaks and their natural enemies across different continents provide an opportunity to test the enemy release hypothesis(ErH)at local and global *** on the ErH,we assessed the impacts of native seed-feeding insects on introduced and native oaks within and among *** combined a common-garden experiment in China and biogeographic literature surveys to measure seed predation by insects and the proportion of acorn embryos surviving after insect infestation among 4 oak species with different geographical origins:Quercus mongolica origin from China,*** and *** from Europe,and *** from North *** supporting the ErH,oaks in introduced continents escaped seed predation compared to those in native continents and compared to other native oaks in introduced ***-garden comparisons showed that total acorn infestation rate of introduced ***(section Lobatae)was considerably lower than that of native oaks(section Quercus)in China and Europe,likely because of the differences in seed traits associated with different oak *** surveys showed that seed predation of introduced oaks was lower in the introduced continent than in the native *** survival was higher in introduced *** than native oaks in China and ***,insect seed predation of recently introduced *** in China was similar to that in Europe,which is not consistent with the *** results suggest that reduced acorn attack by native insects and higher embryo survival after acorn damage could increase the establishment success or invasion risk of introduced oaks in non-native continents.

关键词： acorn performance common garden plant-herbivore interactions species introduction the enemy release hypothesis

Bayesian regularized regression Based on Composite Quantile Method

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Acta Mathematicae Applicatae sinica 2016年第2期32卷 495-512页

作者： Wei-hua ZHAO ri-quan ZHANG Ya-zhao LU Ji-cai LIU school of statistics East China Normal UniversityShanghai 200241China school of science NanTong UniversityNanTong 226007China Department of Mathematics Shanxi Datong UniversityDatong 037009China

recently, variable selection based on penalized regression methods has received a great deal of attention, mostly through frequentist＇s models. This paper investigates regularization regression from Bayesian perspective. Our new method extends the Bayesian Lasso regression （Park and Casella, 2008） through replacing the least square loss and Lasso penalty by composite quantile loss function and adaptive Lasso penalty, which allows different penalization parameters for different regression coefficients. Based on the Bayesian hierarchical model framework, an efficient Gibbs sampler is derived to simulate the parameters from posterior distributions. Furthermore, we study the Bayesian composite quantile regression with adaptive group Lasso penalty. The distinguishing characteristic of the newly proposed method is completely data adaptive without requiring prior knowledge of the error distribution. Extensive simulations and two real data examples are used to examine the good performance of the proposed method. All results confirm that our novel method has both robustness and high efficiency and often outperforms other approaches.

关键词： composite quantile regression variable selection Lasso adaptive Lasso, Gibbs sampler

Mechanism research on arsenic removal from arsenopyrite ore during a sintering process

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International Journal of Minerals,Metallurgy and Materials 2017年第4期24卷 353-359页

作者： ri-jin Cheng Hong-wei Ni Hua Zhang Xiao-kun Zhang si-cheng Bai Key Laboratory for Ferrous Metallurgy and resources Utilization of Ministry of Education Wuhan University of Science and Technology Wuhan 430081 China

The mechanism of arsenic removal during a sintering process was investigated through experiments with a sintering pot and arsenic-bearing iron ore containing arsenopyrite; the corresponding chemical properties of the sinter were determined by inductively coupled plasma atomic emission spectrometry (ICP-AEs), X-ray diffraction (XrD), and scanning electron microscopy (sEM) coupled with energy-dispersive X-ray spectroscopy (EDs). The experimental results revealed that the reaction of arsenic removal is mainly related to the oxygen atmosphere and temperature. During the sintering process, arsenic could be removed in the ignition layer, the sinter layer, and the combustion zone. A portion of FeAss reacted with excess oxygen to generate FeAsO4, and the rest of the FeAss reacted with oxygen to generate As2O3(g) and sO2(g). A portion of As2O3(g) mixed with Al2O3or CaO, which resulted in the formation of arsenates such as AlAsO4and Ca3(AsO4)2, leading to arsenic residues in sintering products. The FeAss component in the blending ore was difficult to decompose in the preliminary heating zone, the dry zone, or the bottom layer because of the relatively low temperatures; however, As2O3(g) that originated from the high-temperature zone could react with metal oxides, resulting in the formation of arsenate residues. © 2017, University of science and Technology Beijing and springer-Verlag Berlin Heidelberg.

关键词： Arsenic Atmospheric temperature Atomic emission spectroscopy Blending Energy dispersive spectroscopy Ignition Inductively coupled plasma Iron ore sinter Iron ores Mechanisms Oxygen Pollution control scanning electron microscopy sulfur dioxide X ray diffraction X ray spectroscopy