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暗物质寻找实验中CsI(Tl)晶体反符合探测器实验研究(英文)

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高能物理与核物理 2006年第6期30卷 548-553页

作者：何道李玉兰岳骞李元景李金程建平 KWAK j W KIM s K 李昕王子敬清华大学工程物理系北京100084 汉城国立大学物理系中研院物理研究所台北11529

一个正在建设的位于韩国Y2L地下实验室的低能暗物质探测实验中,采用了CsI(Tl)晶体反符合探测器作为主动屏蔽体．本工作对CsI(Tl)晶体反符合探测器的实验性能进行了研究．通过FADC系统记录的脉冲波形数据,研究了探测器的能量分辨率和波... 详细信息

一个正在建设的位于韩国Y2L地下实验室的低能暗物质探测实验中,采用了CsI(Tl)晶体反符合探测器作为主动屏蔽体．本工作对CsI(Tl)晶体反符合探测器的实验性能进行了研究．通过FADC系统记录的脉冲波形数据,研究了探测器的能量分辨率和波形甄别的能力;研究相同能量γ射线入射到反符合探测器不同位置的相对光输出将有助于选择探测器的工作参数;为了解晶体自身放射性对暗物质测量的影响,利用低本底HPGe探测器对CsI(Tl)晶体内部的放射性进行了测量,得到晶体内部Cs同位素的放射性活度．探测器系统进行了约18d的试运行取数．实验数据表明,CsI(Tl)晶体探测器的反符合效率约为31％,HPGe探测器的本底计数率水平约为 133cpd．为了进行暗物质探测研究,需要采取有效的方法进一步降低探测器的本底水平．

关键词：暗物质 CsI(Tl)探测器脉冲形状甄别内部本底

Recent progress about transmission electron microscopy characterizations on lithium-ion batteries

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journal of Energy Chemistry 2024年第8期95卷 39-56,I0002页

作者： Yihang liu Qiuyun li Ziqiang Wang Institute of Materials Research Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518000GuangdongChina

With the rapid development of portable electronics,new energy vehicles,and smart grids,ion batteries are becoming one of the most widely used energy storage devices,while the safety concern of ion batteries has always been an urgent problem to be *** develop a safety-guaranteed battery,the characterization of the internal structure is indispensable,where electron microscopy plays a crucial *** on this,this paper summarizes the application of transmission electron microscopy(TEM)in battery safety,further concludes and analyzes the aspects of dendrite growth and solid electrolyte interface(sEI)formation that affect the safety of ion batteries,and emphasizes the importance of electron microscopy in battery safety research and the potential of these techniques to promote the future development of this *** advanced electron microscopy techniques and their prospects are also discussed.

关键词： Electron microscopy characterizations lithium-ion batteries Dendrites sEI

Cellular automaton modeling of austenite formation from ferrite plus pearlite microstructures during intercritical annealing of a C-Mn steel

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journal of Materials science & Technology 2020年第12期47卷 1-9页

作者： Chunni jia Chengwu Zheng Dianzhong li shenyang National Laboratory for Materials science Institute of Metal ResearchChinese Academy of Sciences.Shenyang110016China school of Materials science and Engineering University of Science and Technology of ChinaShenyang110016China

A mesoscopic cellular automaton model was developed to study the microstructure evolution and solute redistribution of austenization during intercritical annealing of a C-Mn steel. This model enables a depiction of three-stage kinetics of the transformation combined with the thermodynamic analysis:(1) the rapid austenite growth accompanied with pearlite degeneration until the pearlite dissolves completely;(2) the slower austenite growth into ferrite with a rate limiting factor of carbon diffusion in austenite;and(3) the slow austenite growth in control of the manganese diffusion until the final equilibrium reached for ferrite and austenite. The effect of the annealing temperature on the transformation kinetics and solute partition is also quantitatively rationalized using this model.

关键词： Austenization Intercritical annealing C-Mn steels Cellular automaton Mesoscale modeling

synthesis, Crystal structure and Optical Properties of a New Nd(III) Nitronyl Nitroxide Complex [Nd(NIT2Py)_2(NO_3)_3]

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Chinese journal of structural Chemistry 2005年第8期24卷 905-908页

作者： li Dong-jiao GAO Dong-Zhao li li-Cun liAO Dai-Zheng jIANG Zong-Hui YAN shi-Ping Department of Chemistry Nankai University ChinaTianjin 300071 state Key Laboratory of structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences ChinaFuzhou Fujian 350002

A new Nd（Ⅲ） nitronyl nitroxide complex [Nd（NIT2Py）2（NO3）3] （NIT2Py = 2-（2＇-pyridyl）-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide） has been synthesized and structurally characterized by X-ray diffraction. It crystallizes in monoclinic, space group P21/n with a = 12.396（4）, b =11.134（4）, c = 23.360（7） A°, β = 98.178（6）°, V= 3191.2（18） A°^3, C24H32N9NdO13, Mr = 798.83, Dc =1.663 g/cm^3, μ（MoKa） = 1.704 mm^-1, F（000） = 1612, Z = 4, the final R = 0.0425 and wR = 0.0957 for 6532 independentreflections with Rint = 0.0642 and 4552 observed reflections （I 〉 2σ（I））. The complex exists as discrete mononuclear molecules and the neodymium（Ⅲ） ion is ten-coordinated with three bidentate nitrate anions and two radical ligands （NIT2Py） via bidentate chelating *** optical properties of the complex are discussed.

关键词： neodymium(Ⅲ)complex nitronyl nitroxide radical crystal structure optical properties

Optimal Operation strategy Analysis with scenario Generation Method Based on Principal Component Analysis,Density Canopy,and K-medoids for Integrated Energy systems

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journal of Modern Power systems and Clean Energy 2024年第1期12卷 89-100页

作者： Bingtuan Gao Yunyu Zhu Yuanmei li school of Electrical Engineering Southeast UniversityNanjingChina

The operation of integrated energy systems(IEss)is confronted with great challenges for increasing penetration rate of renewable energy and growing complexity of energy *** generation is one of ordinary methods to alleviate the system uncertainties by extracting several typical scenarios to represent the original high-dimensional *** paper proposes a novel representative scenario generation method based on the feature extraction of panel *** original high-dimensional data are represented by an aggregated indicator matrix using principal component analysis to preserve temporal ***,the aggregated indicator matrix is clustered by an algorithm combining density canopy and *** with the proposed scenario generation method,an optimal operation model of IEs is established,where the objective is to minimize the annual operation costs considering carbon trading ***,case studies based on the data of Aachen,Germany in 2019 are *** results indicate that the adjusted rand index(ARI)and silhouette coefficient(sC)of the proposed method are 0.6153 and 0.6770,respectively,both higher than the traditional methods,namely K-medoids,K-means++,and density-based spatial clustering of applications with noise(DBsCAN),which means the proposed method has better *** error between optimal operation results of the IEs obtained by the proposed method and all-year time series benchmark value is 0.1%,while the calculation time is reduced from 11029 s to 188 s,which verifies that the proposed method can be used to optimize operation strategy of IEs with high efficiency without loss of accuracy.

关键词： scenario generation principal component analysis(PCA) density canopy K-medoids integrated energy system

Neighboring optimal guidance using higher-order dynamics approximation with application to orbital injection problem

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Chinese journal of Aeronautics 2024年第5期37卷 426-440页

作者： Xinglun CHEN Ran ZHANG Huifeng li school of Astronautics Beihang UniversityBeijing 100191China

Neighboring optimal guidance,a method to obtain a suboptimal guidance law by approximately solving the first-order necessary conditions based on a nominal trajectory,is widely used in the aerospace field due to its high computational efficiency and low resource *** more advanced scenarios,the existing methods still have a problem that the guidance accuracy and optimality will seriously degrade when the actual state largely deviates from the nominal *** is mainly caused by the approximate description of the first-order conditions in terms of total flight time and nonlinear *** address this problem,a higher-order neighboring optimal guidance method is ***,a novel total flight time updating strategy,together with a normalized time scale,is presented that transforms the optimal problem with free total flight time into a more tractable optimal problem with fixed total flight ***,using the vector partial derivative method,a higher-order approximation is adopted,instead of the first-order approximation,to accurately describe the nonlinear dynamical and terminal constraints,thus obtaining a polynomially constrained quadratic optimal ***,to numerically solve the polynomially constrained quadratic optimal problem,a Newton-type iterative algorithm based on the orthogonal decomposition is *** the iterative solution within each guidance period,the corrections to control quantities and total flight time are *** proposed method is applied to a launch vehicle orbital injection problem,and simulation results show that it achieves high accuracy of orbital injection and optimality of performance index.

关键词： Optimal control Neighboring optimal guidance Launch vehicles Orbital injection Higher-order approximation

The simple synthesis of quinazoline-2,4-dione derivatives using Boc strategy

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Chinese Chemical Letters 2009年第10期20卷 1201-1203页

作者： Xu Qin li school of Applied science University of Science and Technology Beijing Beijing 100083 China

Quinazolinediones are particularly attractivc pharrnacophores because of theix wide range of bioactivities. A convenient synthetic pathway to three-substituted quinazolinc-2,4-dionc derivatives was developed from substituted anthranilamide via carbonylation with Boc anhydride and then cyclization in the presence of the base sodium mcthoxidc. Good to cxceUcnt yields have bccn achieved.

关键词： Quinazolinediones Carbonylation Cyclization Boc strategy

Non-epitaxial growth of highly oriented transition metal dichalcogenides with density-controlled twin boundaries

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The Innovation 2023年第6期4卷 30-37页

作者： juntong Zhu Zhili Hu shasha Guo Ruichun Luo Maolin Yu Ang li jingbo Pang Minmin Xue stephen j.Pennycook Zheng li Zhuhua Zhang Wu Zhou school of Physical sciences CAS Key Laboratory of Vacuum PhysicsUniversity of Chinese Academy of SciencesBeijing 100049China state Key Laboratory of Mechanics and Control for Aerospace structures Key Laboratory for Itelligent Nano Materials and Devices of Ministry of Educationand Institute for Frontier ScienceNanjing University of Aeronautics and AstronauticsNanjing 210013China school of Materials science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Environmental Chemistry and Materials Centre Nanyang Environment and Water Research InstituteNanyang Technological UniversitySingapore 637141Singapore

Twin boundaries(TBs)in transition metal dichalcogenides(TMDs)constitute distinctive one dimensional electronic systems,exhibiting intriguing physical and chemical properties that have garnered significant attention in the fields of quantum physics and ***,the controlled manipula-tion of TBs in terms of density and specific atomic configurations remains a fomidable *** this study,we present a non-epitaxial growth approach that enables the controlled and large scale fabrication of homoge-neous catalytically active TBs in monolayer TMDs on arbitrary ***,the density achieved using this strategy is six times higher than that observed in convention chemical vapor deposition(CVD)-grown *** rigorous experimental analysis and multigrain Wulff construc tion simulations,we elucidate theroleof regulating themetal source diffusion process,which serves as the key factor for inducing the self-oriented growth ofTMD grains and the formation of unified ***,we demonstrate that this novel growth mode can be readily incorporated into the conventional CVD growth method by making a simple modification of the growth tempera-ture profle,thereby offering a universal approach for engineering of grain boundaries in two-dimensional materials.

关键词： grain transition tempera

Experimental study on combustion characteristics of supersonic combustor based on alternating-wedge strut

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Chinese journal of Aeronautics 2024年第5期37卷 214-227页

作者： jie li Wenyan sONG Yuhang WANG school of Power Energy Northwestern Polytechnical UniversityXi’an 710129China

Acetone Planar Lase-Induced Fluorescence(PliF)and OH-PliF were employed to capture the fuel distribution and OH distribution downstream for the supersonic combustor based on the alternating-wedge *** combustion establishment process and combustion mode in the combustor under different fuel injection methods and different equivalence ratios were *** with the kerosene-PliF and OH-PliF results in the cavity combustor,a comparative analysis was conducted to understand the combustion characteristics and combustion modes between the alternating-wedge strut-based combustor and the cavity-based *** results show that the combustor is in weak combustion mode in the case of low equivalence ratio,and the combustor is in intensive combustion mode in the case of high equivalence *** lower limit of the equivalence ratio of the combustor to maintain the intensive combustion mode varies based on different fuel injection *** OH distribution under reacting condition has a strong correlation with the fuel distribution under non-reacting *** OH fluorescence signal near the injector is weaker when the fuel distribution is more *** injector position located at the base of the strut rear has better mixing performance,enabling the combustor to be in intensive combustion mode at a lower equivalence *** combustion reaction in the alternating-wedge strut-based combustor is not necessarily dominated by mass transfer due to the mixing enhancement and premixed zone downstream of strut,while the combustion reaction process in the cavity-based combustor is mainly influenced by mass transfer.

关键词： supersonic combustor Alternating-wedge strut Cavity PliF Fuel injection Fuel distribution Combustion characteristics Combustion mode