检索结果-南通市图书馆

Dissociation cross sections ofψ(3770),ψ(4040),ψ(4160),andψ(4415)mesons with nucleons

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 93-112页

作者： ruo-Qing Ding Xiao-ming Xu H j Weber Department of Physics Shanghai UniversityBaoshanShanghai 200444China Department of Physics University of VirginiaCharlottesvilleVA 22904United States of America

We study the dissociation of ψ(3770), ψ(4040), ψ(4160), and ψ(4415) mesons in collision with nucleons, which takes place in high-energy proton-nucleus collisions. The quark interchange between a nucleon and a ■ meson leads to the dissociation of the ■ meson. We consider the reactions:■, and■, where r stands for ψ(3770), ψ(4040), ψ(4160), or ψ(4415). A reaction of a neutron and a ■ meson corresponds to a reaction of a proton and the ■ meson by replacing the up quark with the down quark and vice versa. Transition-amplitude formulas are derived from the S-matrix *** cross sections are calculated with the transition amplitudes for scattering in the prior form and in the post form. The cross sections relate to nodes in the radial wave functions of ψ(3770), ψ(4040), ψ(4160), and ψ(4415) mesons.

关键词： inelastic nucleon-charmonium scattering quark interchange relativistic constituent quark potential model

Temporal and Spectral Characteristics of Persistent Emission and Special Bursts of Magnetar SGr j1935+2154 Based on Insight-HXMT

在线全文

学校读者我要写书评

暂无评论

research in Astronomy and Astrophysics 2024年第6期24卷 225-233页

作者： Xue-Feng Lu Li-ming Song ming-Yu Ge Shuang-Nan Zhang jin-Lu Qu Ce Cai Cong-Zhan Liu Cheng-Kui Li Yu-Cong Fu Ying-Chen Xu Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China College of Physics and Hebei Key Laboratory of Photophysics research and Application Hebei Normal UniversityShijiazhuang 050024China Department of Astronomy Beijing Normal UniversityBeijing 100875China

In October 2022,the magnetar SGr j1935+2154 entered the active outburst *** the episode,the InsightHXMT satellite carried out a long observation that lasted for 20 *** than 300 bursts were detected,and a certain amount of persistent radiation signals were also *** paper mainly introduces the results of persistent radiation profile folding and period search based on Insight-HXMT *** the same time,the burst phase distribution characteristics,spectral lag results of burst,the spectral characteristics of zero-lag bursts and the time-resolved spectral evolution characteristics of high-flux bursts are *** found that there is no significant delay feature during different energy bands for the bursts of SGr j1935+*** observed zero-lag burst does not have a unique *** time-resolved spectrum of the individual burst has consistent spectral types and spectral parameters at different time periods of the *** also find that the burst number phase distribution and the burst photon phase distribution have the same tendency to concentrate in specific regions of the persistent emission profile.

关键词： radiation mechanisms:general dense matter magnetic fields

Leflunomide: A versatile additive for defect reduction, enhanced optoelectronic properties and environmental stability of perovskite films

在线全文

学校读者我要写书评

暂无评论

Nano research 2024年第4期17卷 2628-2637页

作者： Dingyue Sun ming Peng Taijin Wang Longju Yi Shizuo Zhang Feng Liu Gary j.Cheng The Institute of Technological Sciences Wuhan UniversityWuhan 430072China School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China School of Industrial Engineering Purdue UniversityWest LafayetteIN 47906USA

The development of perovskite photoelectric devices with excellent performance is largely dependent on the defects in the perovskite *** address this issue,a specific drug,leflunomide(LF,C_(12)H_(9)F_(3)N_(2)O_(2)),was incorporated into the perovskite to reduce defects and improve its photoelectric *** is believed that the C=O bond on LF molecule can interact with the uncoordinated Pb2+of the perovskite,thereby reducing non-radiative *** novel approach of incorporating LF into perovskite films has the potential to revolutionize the development of high-performance perovskite photoelectric *** trifluoromethyl functional(–CF_(3))group on LF can form a protective layer on the surface of the perovskite film,shielding it from water ***,LF can be utilized to alter the nucleation position of perovskite,thus minimizing the number of defects and optimizing the film ***,the LF-doped perovskite film displays low trap density and high photoelectric *** LF-doped perovskite film showed a trap density of 8.28×10^(11),which is notably lower than the 2.04×10^(12) of the perovskite film without *** responsivity and detectivity of the LF-doped perovskite photodetector were 0.771 A/W and 2.81×10^(11) jones,respectively,which are much higher than the 0.23 A/W and 1.06×10^(10) jones of the LF-undoped perovskite ***,the LF-doped photodetector maintained an initial photocurrent of 86%after 30 days of storage in air,indicating drastically increased environmental *** strongly suggests that LF is an effective additive for perovskites utilized in optoelectronic devices with high performance.

关键词： leflunomide additive engineering defect passivation perovskite

Bayesian inference-based wear prediction method for plain bearings under stationary mixed-friction conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第6期12卷 1272-1282页

作者： Florian KÖNIG Florian WIrSING Georg jACOBS rui HE Zhigang TIAN ming j.ZUO Institute for Machine Elements and Systems Engineering RWTH Aachen UniversityAachen 52062Germany Department of Mechanical Engineering University of AlbertaEdmonton T6G1H9Canada Qingdao International Academician Park research Institute Qingdao 266000China

This study introduces a method to predict the remaining useful life(rUL)of plain bearings operating under stationary,wear-critical *** this method,the transient wear data of a coupled elastohydrodynamic lubrication(mixed-EHL)and wear simulation approach is used to parametrize a statistical,linear degradation *** method incorporates Bayesian inference to update the linear degradation model throughout the runtime and thereby consider the transient,system-dependent wear progression within the rUL prediction.A case study is used to show the suitability of the proposed *** results show that the method can be applied to three distinct types of post-wearing-in behavior:wearing-in with subsequent hydrodynamic,stationary wear,and progressive wear *** hydrodynamic operation leads to an infinite lifetime,the method is successfully applied to predict rUL in cases with stationary and progressive wear.

关键词： plain bearings wear modeling remaining useful life prediction Bayesian inference

Phase-Field Simulation of Sintering Process:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第8期140卷 1165-1204页

作者： ming Xue Min Yi State Key Laboratory ofMechanics and Control forAerospace Structures&Institute for Frontier Science&Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education&College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics(NUAA)Nanjing210016China

Sintering,a well-established technique in powder metallurgy,plays a critical role in the processing of high melting point materials.A comprehensive understanding of structural changes during the sintering process is essential for effective product *** phase-field method stands out for its unique ability to simulate these structural *** its widespread application,there is a notable absence of literature reviews focused on its usage in sintering ***,this paper addresses this gap by reviewing the latest advancements in phase-field sintering models,covering approaches based on energy,grand potential,and entropy *** characteristics of various models are extensively discussed,with a specific emphasis on energy-based models incorporating considerations such as interface energy anisotropy,tensor-form diffusion mechanisms,and various forms of rigid particle motion during ***,the paper offers a concise summary of phase-field sintering models that integrate with other physical fields,including stress/strain fields,viscous flow,temperature field,and external electric *** conclusion,the paper provides a succinct overview of the entire content and delineates potential avenues for future research.

关键词： Phase-field model review sintering additive manufacturing

Classification of complete 3-dimensional self-shrinkers in the Euclidean space r^(4)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第4期67卷 873-882页

作者： Qing-ming Cheng Zhi Li Guoxin Wei Department of Applied Mathematics Faculty of ScienceFukuoka UniversityFukuoka 814-0180Japan College of Mathematics and Information Science Henan Normal UniversityXinxiang 453007China School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

In this paper,we completely classify 3-dimensional complete self-shrinkers with the constant norm S of the second fundamental form and the constant f3in the Euclidean space r^(4),where hij’s are components of the sec... 详细信息

关键词： mean curvature ow self-shrinker the generalized maximum principle

Sequential enantioselective Ugi-4Cr/post-Ugi transformation strategy:a precise construction of structurally diverse azaspiro polycyclic scaffolds

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 576-586页

作者： Xiao-Bao Wu jun-Xiu Shi Yi-ming Ou Hua-jie jiang Yi-jun Fang Qi-ming Wang Quan Gao jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and ApplicationAnhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefei230036China

A privileged strategy has been developed for the precise construction of enantioenriched azaspiro polycyclic *** diverse azaspiro polycycles bearing multiple contiguous stereocenters are obtained with excellent results(up to 99:1 e.r.,>95:5 d.r.) via sequential enantioselective four-component Ugi reactions/post-Ugi transformations with substrates containing prerequisite functional groups in the presence of anionic stereogenic-at-cobalt(Ⅲ) complexes.

关键词： asymmetric catalysis post-Ugi transformation anionic stereogenic-at-cobalt(Ⅲ)complex azaspiro polycyclic scaffold one-pot synthesis

Experimental study of face passive failure features of a shallow shield tunnel in coastal backfill sand

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第2期18卷 252-271页

作者： Weifeng QIAN ming HUANG Bingnan WANG Chaoshui XU Yanfeng HU School of Civil Engineering Fuzhou UniversityFuzhou 350108China School of Civil Environment and Mining EngineeringUniversity of AdelaideAdelaide 5005Australia China First Highway Xiamen Engineering Co. Ltd.Xiamen 361000China

Face passive failure can severely damage existing structures and underground utilities during shallow shield tunneling,especially in coastal backfill *** this work,a series of laboratory model tests were developed and conducted to investigate such failure,for tunnels located at burial depth ratios for which C/D=0.5,0.8,1,and *** pressures,the evolution of failure processes,the failure modes,and the distribution of velocity fields were examined through model tests and numerical *** support pressure in the tests first rose rapidly to the elastic limit and then gradually increased to the maximum value in all *** maximum support pressure decreased slightly in cases where C/D=0.8,1,and 1.3,but the rebound was insignificant where C/D=*** addition,the configuration of the failure mode with C/D=0.5 showed a wedge-shaped arch,which was determined by the outcropping shear *** configuration of failure modes was composed of an arch and the inverted trapezoid when C/D=0.8,1,and 1.3,in which the mode was divided into lower and upper failure zones.

关键词： tunnel face stability passive failure model test support pressure failure mode

Timing and Spectral Analysis of the Black Hole X-ray Binary MAXI j1803-298 with Insight-HXMT Data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

research in Astronomy and Astrophysics 2024年第6期24卷 209-224页

作者： Ying-Chen Xu jin-Lu Qu MMéndez rui-Can Ma Long ji Liang Zhang Yue Huang Qing-Cui Bu Li-ming Song Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Kapteyn Astronomical Institute University of GroningenP.O.BOX 8009700 AV GroningenThe Netherlands Dongguan Neutron Science Center Dongguan 523808China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China Institut für Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard Karls UniversitätSand 1D-72076 TübingenGermany

We present a comprehensive analysis of the 2021 outburst of MAXI j1803–298 utilizing observations of the Insight-Hard X-ray Modulation Telescope(Insight-HXMT)spanning from the low hard state to the high soft *** the Insight-HXMT data set,compared to the previous work,we identify a more prolonged presence of typeC quasi-periodic oscillations(QPOs)with centroid frequencies ranging from~0.16 to 6.3 Hz,which present correlations with the hardness ratio and the photon index of the Comptonized *** QPO frequencies less than~2 Hz,the QPO phase lags are hard(photons of 10–19 keV arrive later than those of 1–4 keV),while at higher frequencies,the lags become soft at and above~4 ***,the spectra in all Insight-HXMT observations consist of a multi-color blackbody component and a Comptonized component,as commonly observed in classical black hole X-ray *** analyze state transitions and the evolution of accretion geometry in this *** fitted inner disk radius increases abnormally during the low hard state,hypothesized to result from the corona condensing onto the inner ***,two significant drops in flux are observed during the soft intermediate state,maybe implying changes in the corona/jet and the disk,respectively.

关键词： X-rays:binaries accretion accretion disks stars:black holes