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The afterglow emission from a stratified jet in GRB 170817A

Research in Astronomy and Astrophysics 2021年第7期21卷 223-233页

作者： Kang-Fa Cheng xiao-Hong Zhao bin-bin Zhang Jin-Ming Bai Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of the Chinese Academy of Sciences Beijing 100049China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China Key Laboratory for the Structure and evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China School of Astronomy and Space Science Nanjing UniversityNanjing 210093China Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 210046China Department of Physics and Astronomy University of Nevada Las VegasNV 89154USA

The afterglow of GRB 170817 A has been detected for more than three years,but the origin of the multi-band afterglow light curves remains under debate.A classical top-hat jet model is faced with difficulties in producing a shallow rise of the afterglow light curves as observed(e_(v) ∝ T^(0.8)).Here we reconsider the model of stratified ejecta with an energy profile of e(> Γβ)=e_0(Γβ)^(-k) as the origin of the afterglow light curves of the burst,where Γ and β are the Lorentz factor and speed of the ejecta,respectively.k is the power-law slope of the energy *** consider that the ejecta are collimated into *** kinds of jet evolutions are investigated,including a lateral-spreading jet and a non-lateral-spreading *** fit the multi-band afterglow light curves,including the x-ray data at one thousand days post-burst,and find that both the models of the spreading and non-spreading jets can fit the light curves well,but the observed angular size of the source and the apparent velocity of the flux centroid for the spreading jet model are beyond the observation limits,while the non-spreading jet model meets the observation *** of the best-fit parameters for the non-spreading jet model,such as the number density of the circumburst medium~10^(-2) cm^(-3) and the total jet kinetic energy e ~ 4.8 × 10^(51) erg,also appear *** best-fit slope of the jet energy profile is k ~*** results suggest that the afterglow of GRB 170817 A may arise from the stratified jet and that the lateral spreading of the jet is not significant.

关键词： gamma-ray burst:general stars:jets relativistic processes

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Bifurcation and buckling analysis of a unilaterally confined self-rotating cantilever beam

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Acta Mechanica Sinica 2006年第2期22卷 177-184页

作者： Shifu xiao bin Chen Min Yang Southwest Institute of Structural Mechanics EO. Box 919-401 Mianyang 621900 China Department of Mechanics & engineering Science PKU Beijing 100871 China

A nonlinear dynamic model of a simple nonholonomic system comprising a self-rotating cantilever beam subjected to a unilateral locked or unlocked constraint is established by employing the general Hamilton＇s Variational Principle. The critical values, at which the trivial equilibrium loses its stability or the unilateral constraint is activated or a saddle-node bifurcation occurs, and the equilibria are investigated by approximately analytical and numerical methods. The results indicate that both the buckled equilibria and the bifurcation mode of the beam are different depending on whether the distance of the clearance of unilateral constraint equals zero or not and whether the unilateral constraint is locked or not. The unidirectional snap-through phenomenon （i.e. catastrophe phenomenon） is destined to occur in the system no matter whether the constraint is lockable or not. The saddle-node bifurcation can occur only on the condition that the unilateral constraint is lockable and its clearance is nonzero. The results obtained by two methods are consistent.

关键词： Non-holonomic system Bifurcation Buckling Assumed modes method Shooting method

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A distributed localization in wireless sensor networks utilizing AOD estimation and synthetical uniform circular array

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Science China(Information Sciences) 2015年第6期58卷 105-115页

作者： LI bin WANG WenJie YIN QinYe School of electronics and Information Northwestern Polytechnical University School of electronics and Information engineering Xi'an Jiaotong University

The localization of wireless sensor nodes is one of the key technologies in wireless sensor networks(WSN). Recently, a distributed localization method has been proposed based on a novel concept of angle of departure(AOD) estimation, which can be employed by e.g., the single antenna sensors to estimate the angle information and achieve localization. Based on the AOD estimation, in this paper, we introduce a synthetic uniform circular array(SUCA) synthesized by a rotary antenna on anchor to get the distributed localization of the sensors in multi-path environments. The rotated operation of antenna could create the SUCA with a larger aperture to deal with AOD of multipath components(MPCs) and relax the condition that array aperture should be greater than the number of MPCs. This new localization method only relies on radio transceivers without requiring extra measuring equipments, and the sensor nodes conduct localization in a completely distributed manner instead of centralized processing, which is suitable for large-scale WSN. Meanwhile, the influence of carrier frequency offset(CFO) between the transceivers is also considered and it is eliminated by utilizing the signal emitted from an auxiliary antenna.

关键词： WSN nodes localization AOD multi-path channel rotary antenna SUCA

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Modelling of finger-like channelled anode support for SOFCs application

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Science Bulletin 2016年第17期61卷 1324-1332页

作者： bin Chen Haoran xu Meng Ni Building energy Research Group Department of Building and Real EstateThe Hong Kong Polytechnic University

This paper established a numerical model for a solid oxide fuel cell （SOFC） button cell, focusing on the effects of finger-like channels on the gas transport process in the anode support. The current densities of channelled button cell and un-channelled button cell are compared at different operating temperature and voltage with H2 as the fuel. The H2 transport is discussed in detail, such as the mole fraction distribution of H2 in the porous layer, the diffusion flux and convective flux of Ha. It is found that the performance of SOFC can be improved by 2.60 % at 800 ~C, 0.5 V, com- pared with un-channelled SOFC due to the improved gas transport by the finger-like channels. Then, the model is further ex.ended to study 2D-planar SOFC fuelled with syngas. The mole fraction gradients of H2, CO, CH4 and CO are all substantially reduced by the finger-like channels compared to un-channelled planar cell. It is found that the SOFC performance is improved by 5.93 % at 800℃, 0.5 V, when syngas fuel is used. The present study clearly demonstrated that the use of finger-like channels in the anode support is effective in improving the gas transport and the SOFC performance. The present model can be employed for subsequent optimization of the channel configuration for further performance improvement.

关键词： Phase inversion CFD modelling Finger-like channels Concentration loss

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Measurement of length-scale and solution of cantilever beam in couple stress elasto-plasticity

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Acta Mechanica Sinica 2009年第3期25卷 381-387页

作者： bin Ji Wanji Chen Jie Zhao State Key Laboratory for Structural Analysis of Industrial equipment Dalian University of Technology 116023 Dalian China Department of Aeronautics and Space Navigation Shenyang Institute of Aeronautical Engineering Daoyi South Street 37 110136 Shenyang Liaoning China

Owing to the absence of proper analytical solution of cantilever beams for couple stress/strain gradient elasto-plastic theory, ex.erimental studies of the cantilever beam in the micro-scale are not suitable for the determination of material length-scale. Based on the couple stress elasto-plasticity, an analytical solution of thin cantilever beams is firstly presented, and the solution can be regarded as an ex.ension of the elastic and rigid-plastic solutions of pure bending beam. A comparison with numerical results shows that the current analytical solution is reliable for the case of σ0 〈〈 H 〈〈 e, where σ0 is the initial yield strength, H is the hardening modulus and e is the elastic modulus. Fortunately, the above mentioned condition can be satisfied for many metal materials, and thus the solution can be used to determine the material length-scale of micro-structures in conjunction with the ex.eriment of cantilever beams in the micro-scale.

关键词： Material length-scale Couple stress elasto-plasticity Analytical solution Cantilever beam

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Abnormal skeletal metabolism and its changes after decopper therapy in patients with Wilson disease

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Neural Regeneration Research 2006年第7期1卷 626-629页

作者： Guang'e Yang Minfan Hong bin Yang Renmin Yang xun Wang Department of Neurology Affiliated Hospital of Institute of Neurology Anhui College of Traditional Chinese MedicineHefei 230061Anhui ProvinceChina Department of NeurologyAffiliated Hospital of Institute of Neurology Anhui College of Traditional Chinese MedicineHefei 230061Anhui ProvinceChina Department of NeurologyAffiliated Hospital of Institute of Neurology Anhui College of Traditional Chinese MedicineHefei 230061Anhui ProvinceChina Department of NeurologyAffiliated Hospital of Institute of Neurology Anhui College of Traditional Chinese MedicineHefei 230061Anhui ProvinceChina Department of NeurologyAffiliated Hospital of Institute of Neurology Anhui College of Traditional Chinese MedicineHefei 230061Anhui ProvinceChina

BACKGROUND: Researches indicate that patients with Wilson disease (WD) have abnormal skeletal metabolism, which is induced by various factors. OBJeCTIVe: To probe into the changing characteristics of abnormal skeletal metabolism in WD patients and observe the effect of decopper therapy. DeSIGN: Case-contrast and self-control study. SeTTING: Department of Neurology, Affiliated Hospital of Neurological Institute, Anhui College of Traditional Chinese Medicine. PARTICIPANTS: A total of 35 patients with WD including 21 males and 14 females aged from 10 to 42 years with the mean age of (20±8) years were selected from Department of Neurology, Affiliated Hospital of Neurological Institute, Anhui College of Traditional Chinese Medicine from September 2000 to February 2001. All the patients were in compliance with the diagnostic criteria: history of family heredity; cone symptoms in vitro, physical sign or liver symptoms; positive Kayser-Fleischer ring; serum copper protein er oxidase e copper > 1.6 μmol/24 hours; liver copper > 250 μg/g (dry weight). The control group was selected from 25 cases of health individuals including 13 males and 12 females aged from 16 to 35 years with the mean age of (22±6) years. All patients who participated in the study were informed first and consented. MeTHODS: Patients in treatment group were treated with venous injection of 1.0 g sodium dimercaptosulfonate, once a day for totally 6 successive days. And then, patients rested for 2 days. This procedure mentioned above was regarded as a course, and the treatment lasted for 4-8 courses. Before and after injection of sodium dimercaptosulfonate, serum calcitonin (CT), osteocalcin (BGP), parathyroid hormone (PTH) and 1,25-(OH)2VitD3 were measured with radio-immunity method; blood, urine calcium, phosphorum and urine creatinine were measured with biochemical analyzer; urine dihydropyrimidine dehydrogenase(DPD) was detected with enzyme-immunity method; bone mineral den

关键词： Wilson Abnormal skeletal metabolism and its changes after decopper therapy in patients with Wilson disease

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Controlled growth of Au/Ni bimetallic nanocrystals with different nanostructures

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Rare Metals 2017年第4期36卷 229-235页

作者： Si-bin Duan Rong-Ming Wang School of Mathematics and Physics University of Science and Technology Beijing Beijing 100083 China

Bimetallic nanomaterials are of great signifi- cance to both fundamental research and industrial appli- cations. Their physicochemical performances are critically dependent on their architectures and electronic structures. Here, it was reported a controlled synthesis of Au/Ni bimetallic nanocrystals with different nanostructures, i.e., dumbbell, core@shell and alloyed nanostructures in a one- pot synthesis procedure. Detailed structural characteriza- tions were conducted with the combination of transmission electron microscopy （TeM） and x-ray diffraction （xRD）. even there is a large lattice mismatch between Au and Ni, Au@Ni core@shell nanocrystals are obtained with the seeded growth method. The growth mechanism was deeply investigated. Triphenylphosphine is demonstrated to be an effective capping agent to modify the interfacial energy to form core@shell nanocrystals, and the higher temperature is proved to be a key role in obtaining alloyed nanocrystals.

关键词： Bimetallic nanomaterials Au/Ni nanocrystals Interfacial energy Core@shell structure

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electrochemical anodic oxidation assisted fabrication of memristors

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International Journal of extreme Manufacturing 2024年第3期6卷 250-272页

作者： Shuai-bin Hua Tian Jin xin Guo School of Materials Science and engineering State Key Laboratory of Material Processing and Die&Mould TechnologyHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China

Owing to the advantages of simple structure,low power consumption and high-density integration,memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile memories,neuromorphic computation and data ***,the deposition of memristive films often requires ex.ensive equipment,strict vacuum conditions,high energy consumption,and ex.ended processing *** contrast,electrochemical anodizing can produce metal oxide films quickly(e.g.10 s) under ambient *** means of the anodizing technique,oxide films,oxide nanotubes,nanowires and nanodots can be fabricated to prepare *** film thickness,nanostructures,defect concentrations,etc,can be varied to regulate device performances by adjusting oxidation parameters such as voltage,current and *** memristors fabricated by the anodic oxidation technique can achieve high device consistency,low variation,and ultrahigh yield *** article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of ***,the principle of anodic oxidation is introduced;then,different types of memristors produced by anodic oxidation and their applications are presented;finally,features and challenges of anodic oxidation for memristor production are elaborated.

关键词： anodic oxidation anodized aluminium oxide memristor resistive switching electrical properties

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New Multi-soliton Solutions for the (2+1)-Dimensional Kadomtsev-Petviashvili equation

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Communications in Theoretical Physics 2008年第3期49卷 585-589页

作者： Zhaqilao LI Zhi-bin Department of Computer Science East China Normal University Shanghai 200062 China College of Mathematics Science Inner Mongolia Normal University Huhhot 010022 China

In this paper, an explicit N-fold Darboux transformation with multi-parameters for both a （1＋1）- dimensional Broer-Kaup （BK） equation and a （1＋1）-dimensional high-order Broer-Kaup equation is constructed with the help of a gauge transformation of their spectral problems. By using the Darboux transformation and new basic solutions of the spectral problems, 2N-soliton solutions of the BK equation, the high-order BK equation, and the Kadomtsev-Petviashvili （KP） equation are obtained.

关键词： Darboux transformation soliton solution KP equation BK equation

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Unleashing chemical power from protein sequence space toward genetically encoded “click” chemistry

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Chinese Chemical Letters 2017年第11期28卷 2078-2084页

作者： Fei Sun Wen-bin Zhang Department of Chemical and Biological engineering The Hong Kong University of Science and Technology Key Laboratory of Polymer Chemistry & Physics of Ministry of education Center for Soft Matter Science and Engineering College of Chemistry and Molecular Engineering Peking University

Synthesis of macromolecular systems with precise structural and functional control constitutes a fundamental challenge for materials science and engineering. Development of the ability to construct complex bio-macromolecular architectures provides a solution to this challenge. The past few years have witnessed the emergence of a new category of peptide-protein chemistry which can covalently stitch together protein]peptide molecules with high specificity under mild physiological conditions. It has thus inspired the concept of genetically encoded click chemistry （GeCC）. As a prototype of GeCC, SpyTag/ SpyCatcher chemistry has enabled the precise synthesis ofmacromolecules both in vitro and in vivo, exerting precise control over the fundamental properties of these macromolecules including length, sequence, stereochemistry and topology and leading to the creation of diverse biomaterials for a variety of applications. We thus anticipate a potential toolbox of GeCC comprising multiple mutually orthogonal, covalent-bond forming peptide-protein reactive pairs with diverse features, which shall bridge synthetic biology and materials science and open up enormous opportunities for biomaterialsin the future.

关键词： Genetically encoded click chemistry SpyTag SpyCatcher Topology Protein engineering

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