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Highlights of light meson spectroscopy at the BESⅢ experiment

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National Science Review 2021年第11期8卷 6-17页

作者： shan jin Xiaoyan Shen School of Physics Nanjing University Institute of High Energy Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

Hadron spectroscopy provides a way to understand the dynamics of the strong interaction. For light hadron systems, only phenomenological models or lattice quantum chromodynamics(QCD) are applicable,because of the failure of perturbation expansions for QCD at low energy. Experimental data on light hadron spectroscopy are therefore crucial to provide necessary constraints on various theoretical models. Light meson spectroscopy has been studied using charmonium decays with the Beijing Spectrometer Experiment(BES) at the Beijing Electron-Positron Collider, operating at 2.0–4.6 Ge V center-of-mass energy, for nearly three decades. Charmonium data with unprecedented statistics and well-defined initial and final states provide BESⅢ with unique opportunities to search for glueballs, hybrids and multi-quark states, as well as perform systematic studies of the properties of conventional light mesons. In this article, we review BESⅢ results that address these issues.

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Electromagnetic Properties of a New Microwave Plasma Torch with Double Resonance Configuration

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Chemical Research in Chinese Universities 2016年第4期32卷 549-555页

作者： YU Bingwen jin Wei ZHU Dan YING Yangwei YU Haixiang shan jin XU Chen LIU Wenlong jin Qinhan Research Center for Analytical Instrumentation Institute of Cyber-systems and ControlCollege of Control Science and Engineering Zhejiang University Hangzhou 310058 P. R. China Zhejiang Supcon Research Co. Ltd. Hangzhou 310058 P. R. China

In order to obtain a stable plasma and improve the performance of the torch for atomic emission spectroscopy（AES）, the structure of microwave plasma torch（MPT） was analyzed. The transmission and distribution characteristics of the electromagnetic field of the torch configuration with two or three concentric tubes, as well as the metal spacer between inner and intermediate tubes with different depths were simulated with electromagnetic simula- tion software and verified by experiments. The results indicate that the inner tube of MPT plays an important role in strengthening the electric field intensity at the opening end of the MPT and redistributing the electromagnetic field in the whole torch by forming a double resonance configuration, and contributes to enhancing the macroscopic stability and the self-sustainment of the plasma. The stability of the plasma is proved to be excellent when the metal spacer between the inner and intermediate tubes is located at a place 20-30 mm away from the top opening of the torch. A proper location of the spacer can also avoid the formation of a static filament plasma or a rotating plasma rooted from the outer wall of the inner tube. With the help of morphological analysis, the underlying reason why MPT possesses a great tolerance to wet aerosols and air introduction was clearly made, that is, the formation region of the plasma formed with MPT is apparently separated from the reaction zone of it.

关键词： Microwave plasma torch(MPT) Double resonance configuration Electromagnetic simulation

Effect of Environmental Gradients on the Quantity and Quality of Fallen Logs in Tsuga longibracteata Forest in Tianbaoyan National Nature Reserve, Fujian Province,China

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Journal of Mountain Science 2013年第6期10卷 1118-1124页

作者： YOU Hui-ming HE Dong-jin YOU Wei-bin LIU jin-shan CAI Chang-tang Fujian Agriculture and Forestry University Fujian Academy of Forestry Science Tianbaoyan National Nature Reserve

We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n 0f fallen l0gs in the different f0rest c0mmunities and t0 analyze the relati0nships am0ng stand structure, t0p0graphic fact0rs and human disturbance. The v0lume, c0vered area, mean l0g length and number 0f fallen l0gs differed significantly am0ng f0rest types （P 〈 0.05）, but mean diameter at breast height sh0wed n0 significant difference （P 〉 0.05）. The l0g v0lume and c0vered area in different f0rest types sh0wed the f0ll0wing trend： T. l0ngibracteata pure f0rest 〈 T. l0ngibracteata ＋ Olig0staehyum scabrifl0rur 〈 T. l0ngibraeteata ＋ hardw00d 〈 Rh0d0dendr0n simiarum ＋ T. l0ngibraeteata 〈 T. l0ngibraeteata ＋ Phyll0stachys heter0cycla pubescens. The spatial distributi0n patterns 0f l0gs quantity and quality indicated that l0g v0lume and c0vered area were str0ngly affected by envir0nmental fact0rs in the f0ll0wing 0rder： human disturbance 〉 elevati0n 〉 sl0pe p0siti0n 〉 b0le height 〉 tree height 〉 sl0pe aspect 〉 density 〉 basal area 〉 sl0pe gradient. The relative c0ntributi0n 0f envir0nmental variables 0n the t0tal variance was t0p0graphy （76%）〉 disturbance （42%）〉 stand structure （35%）. T0p0graphy and disturbance c0mbined explained 8.2% 0f the variance. Fallen l0~s auantitv and aualitvwere negatively related t0 elevati0n and sl0pe p0siti0n, and p0sitively ass0ciated t0 human disturbance. The l0g v0lume decreased fr0m n0rthern t0 s0uthern sl0pes. Envir0nmental fact0rs had the highest impact 0n class I （slightly decayed）, and l0west impact 0n class V （highly decayed）.

关键词： Fallen logs Distribution patterns Topography Human disturbance TianbaoyanNational Nature Reserve

Transition of solidification path in nonequilibrium solidification of Ti–48Al–8Nb alloy

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Rare Metals 2016年第1期35卷 48-53页

作者： Tan He Rui Hu Jie-Ren Yang Tie-Bang Zhang jin-shan Li The State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical University

The solidification behavior of Ti-48Al-8Nb alloy under nonequilibrium solidification conditions was studied by electromagnetic levitation *** solidification conditions are different undercooling（△T）under the same cooling condition and different cooling methods at the same undercooling condition,*** different undercooling conditions,when the undercooling is above a critical value（△T＊≈211K）,a remarkable morphological transition from typical hypoperitectic solidification to a sole solidification of the（3 phase resulting in the suppression of the peritectic reaction *** melts with different cooling conditions at the same undercooling（△T≈85 K）,the melt was rapidly cooled by quenching them in cooling *** cooling rate increasing,a transition from β phase to peritectic α phase solidification mode is revealed for Ti-48Al-8Nb alloy.

关键词： TiAl alloy Undercooling Nonequilibriumsolidification Microstructure evolution

Solidification microstructure characteristics of Ti–44Al–4Nb–2Cr–0.1B alloy under various cooling rates during mushy zone

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Rare Metals 2016年第1期35卷 35-41页

作者： Peng Han Hong-Chao Kou Jie-Ren Yang Guang Yang jin-shan Li The State Key Laboratory of Solidification Processing Northwestern Polytechnical University

Beta-solidifying TiAl alloy has great potential in the field of aero-industry as a cast *** the present work,the influence of cooling rate during mushy zone on solidification behavior of Ti-44Al-4Nb-2Cr-0.1B alloy was investigated.A vacuum induction heating device combining with temperature control system was *** Ti-44Al-4Nb-2Cr-0.1B alloy solidified from superheated was melted to β phase with the cooling rates of 10,50,100,200,400 and 700 K·min^（-1）,*** show that with the increase in cooling rate from 10 to 700 K·min^（-1）,the colony size of α_2/γ lamella decreases from 1513 to48 urn and the solidification segregation significantly *** the content of residual B2 phase within α_2/γlamellar colony decreases with the increase in cooling *** addition,the alloy in local interdendritic regions would solidify in a hypo-peritectic way,which can be attributed to the solute redistribution and enrichment of Al element in solidification.

关键词： β-solidifying TiAl alloy Cooling rate Mushyzone Solidification microstructure

Spheroidizing Behavior and Spheroidizing Kinetics of W-phase During Solid-Solution Treatment in Mg–Zn–Y–Mn–(B)Alloys

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Acta Metallurgica Sinica(English Letters) 2017年第5期30卷 464-469页

作者： Kai Yang jin-shan Zhang Xi-Mei Zong Wei Liu Chun-Xiang Xu College of Materials Science and Engineering TaiyuanUniversity of Technology Taiyuan 030024 China shanxi Key Laboratory of Advanced Magnesium-based Materials Taiyuan 030024China

The spheroidizing mechanism of W-phase in the Mg–Zn–Y–Mn–（B） alloys during solid-solution treatment was investigated by using kinetic methodologies. The microstructure and mechanical properties of heat-treated Mg_（94）Zn_（2.5）-Y_（2.5）Mn_1 alloy containing 0.003 wt% B were compared with heat-treated Mg_（94）Zn_（2.5）-Y_（2.5）Mn_1 alloy. The heat-treated Mg_（94）Zn_（2.5）-Y_（2.5）Mn_1 alloy with 0.003 wt% B contained fine and uniform W-phase particles, which exhibited optimal mechanical performance. The ultimate tensile strength, yield strength and elongation were 287.7, 125.5 MPa and 21.1%,respectively.

关键词： Magnesium alloys W-phase Spheroidizing Kinetics Microstructure Mechanical properties

Parameterized expressions for an improved Rouse equation

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International Journal of Sediment Research 2013年第4期28卷 523-534页

作者： Chen CHENG Zhi-yao SONG Yi-gang WANG jin-shan ZHANG School of Marine Sciences Nanjing University of Information Science&Technology Key Laboratory of Virtual Geographic Environment under Ministry of Education and Jiangsu Key Laboratory for Numerical Simulation of Large-Scale Complex SystemNanjing Normal University College of Harbor Coastal and Offshore EngineeringHohai University River Harbor Engineering Department Nanjing Hydraulic Research Institute

The equilibrium profile of suspended sediment concentration（SSC） in steady,uniform turbulent flow has been extensively studied since the proposition of Rouse equation（Rouse,1937）.Many researchers keep studying and attempting to improve the Rouse equation by modifying the mixing length *** and Dey（2009） improved Rouse equation based on the modified sediment diffusivity,however,their proposed sediment diffusivity has two parameters,the depth modification factor α and the reciprocal of the sediment Schmidt number β=1/S;,and the corresponding expressions were not given properly in their *** paper aims to parameterize the relevant coefficients,the results shows:（1）α is parameterized from a reasonable approximation by the analysis of surface boundary condition of SSC;（2） considering some effect factors on the settling velocity,β can be expressed by an extended and modified Montcs-Ippen formula,and its related parameters are calibrated by substantial data about the relationship between the primary Rouse parameter Z.= ω;/*** its counterpart Z.’=ω;/β*** verification with some experimental and field datasets,and comparison with related formula,the results show that the sediment diffusivity and SSC profiles have a good agreement with measured data used the present parameterized expressions of a and β,so the present improved Rouse equation is reasonable,and can be applied in practical ***,an approximation and simplified expression of the improved Rouse equation is deduced by using the approach of perturbation,which can be applied easily for the estimation of suspended sediment transport rate.

关键词： Improved Rouse equation Parameterization Sediment transport

Robust M-estimate of GJR Model with High Frequency Data

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Acta Mathematicae Applicatae Sinica 2015年第3期31卷 591-606页

作者： jin-shan HUANG Wu-qing WU Zhao CHEN Jian-jun ZHOU Department of Statistics and Finance University of Science and Technology of China School of Business Renmin University of China Princeton University Department of Statistics Yunnan University

In this paper, we study the GJR scaling model which embeds the intraday return processes into the daily GJR model and propose a class of robust M-estimates for it. The estimation procedures would be more efficient when high-frequency data is taken into the model. However, high-frequency data brings noises and outliers which may lead to big bias of the estimators. Therefore, robust estimates should be taken into consideration. Asymptotic results are derived from the robust M-estimates without the finite fourth moment of the innovations. A simulation study is carried out to assess the performance of the model and its *** M-estimate of GJR model is also applied in predicting Va R for real financial time series.

关键词： GJR model GARCH model Robust M-estimates scaling model volatility proxy

Research on Bast Fiber Extracted from the White Bark of Three Species in the Genus Broussonetia

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Chinese Journal of Polymer Science 2024年第6期42卷 729-738页

作者： shan-shan jin Si-Nong Wang Yan-Yan Huang jing-Yu Zhang Peng Liu Hui Yu Hong-Dong Zhang Yu-Liang Yang Institute for Preservation and Conservation of Chinese Ancient Books Fudan University LibraryFudan UniversityShanghai200433China State key laboratory of Molecular Engineering of polymers Department of Macromolecular ScienceFudan UniversityShanghai200433China

Against the backdrop of a global paper resource shortage,there is a growing need to identify fast-growing tree species capable of producing long-lasting *** plant species namely Broussonetia kazinoki,Broussonetia papyrifera and hybrid paper mulberry,belong to the Broussonetia genus,were collected from China to study their white bark suitability for pulp and *** chemical composition revealed that the holocellulose content in Broussonetia kazinoki and Broussonetia papyrifera was more than 80%.The molecular weight distribution of several holocellulose/α-cellulose is observed by GPC,which allows us to better observe the changes of various components on the molecular *** yield,lignin,whiteness,and molecular weight of the pulps obtained by NaOH treatment were *** microscope was used to characterize the fiber length-width ratio and ***,the improvement of the fiber rigidity method based on the Kratky-Porod chain model makes it more theoretical and further reveals the influencing factors of fiber *** study demonstrates the high potentiality of these three species for papermaking applications.

关键词： Broussonetia genus Cellulose Alkaline pulping Kratky-Porod chain model Fiber rigidity