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Precise determination of the pole position of the exotic Z_(c)(3900)

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 84-90页

作者： Yun-hua Chen meng-Lin Du Feng-Kun Guo School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China School of Physics University of Electronic Science and Technology of ChinaChengdu 611731China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Peng huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China

We perform a unified description of the experimental data of the π^(+)π^(-)and J/ψπ^(±)invariant mass spectra for e^(+)e^(-)→J/ψπ^(+)π^(-)and the D^(0)D^(*-)mass spectrum for e^(+)e^(-)→D^(0)D^(*-)π^(+)at e^(+)e^(-)center-of-mass energies 4.23 and 4.26 *** analysis takes into account open-charm meson loops that contain triangle singularities,the J/ψπ-DD^(*)coupled-channel interaction respecting unitarity,and the strong ππ-KK final state interaction using dispersion *** analysis leads to a precise determination of the Z_(c)(3900)pole with the pole mass and width(3880.7±1.7_(stat)±22.4_(syst))MeV and(35.9±1.4_(stat)±15.3_(syst))MeV,respectively,and hints at that the DD^(*)molecular and non-molecular components are of similar importance in the Z_(c)(3900)formation.

关键词： exotic hadrons dispersion relations final state interaction triangle singularity

Critical behaviors of a(2+1)-dimensional black hole with a nonlinear electrodynamics source

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Communications in Theoretical Physics 2020年第10期72卷 125-130页

作者： Li-hua Wang Yun He meng-Sen Ma Department of Physics Shanxi Datong University037009 DatongChina State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University710049 Xi'anChina Institute of Theoretical Physics Shanxi Datong University037009 DatongChina

On the basis of a charged BTZ black hole,we add an extra term in the metric function to describe the contribution from nonlinear *** this way we artificially construct a(2+1)-dimensional black hole in general relativity coupled with a nonlinear electrodynamics *** thermodynamic quantities and Smarr formula are *** is found that this black hole has T-S criticality like that of an RN-Ad S black *** modifying the metric function,we obtain a(2+1)-dimensional black hole possessing P-V critical behaviors similar to that of van der Waals *** our knowledge,this is the first example of(2+1)-dimensional black holes having this kind of critical behavior.

关键词： phase transition critical phenomena (2+1)-dimensional black hole nonlinear electrodynamics

Multi-objective optimization design method of the high-speed train head

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第9期14卷 631-641页

作者： meng-ge YU Ji-ye ZHANG Wei-hua ZHANG State Key Laboratory of Traction Power Southwest Jiaotong University

With the continuous improvement of the train speed, the dynamic environment of trains turns out to be aerodynamic domination. Solving the aerodynamic problems has become one of the key factors of the high-speed train head design. Given that the aerodynamic drag is a significant factor that restrains train speed and energy conservation, reducing the aerodynamic drag is thus an important consideration of the high-speed train head design. However, the reduction of the aerodynamic drag may increase other aerodynamic forces (moments), possibly deteriorating the operational safety of the train. The multi-objective optimization design method of the high-speed train head was proposed in this paper, and the aerodynamic drag and load reduction factor were set to be optimization objectives. The automatic multi-objective optimization design of the high-speed train head can be achieved by integrating a series of procedures into the multi-objective optimization algorithm, such as the establishment of 3D parametric model, the aerodynamic mesh generation, the calculation of the flow field around the train, and the vehicle system dynamics. The correlation between the optimization objectives and optimization variables was analyzed to obtain the most important optimization variables, and a further analysis of the nonlinear relationship between the key optimization variables and the optimization objectives was obtained. After optimization, the aerodynamic drag of optimized train was reduced by up to 4.15%, and the load reduction factor was reduced by up to 1.72%.

关键词： High-speed train Multi-objective optimization Parametric model Aerodynamic drag Load reduction factor

Preoperative evaluation and outcome of corneal transplantation for limbal dermoids：aten-yearfollow-up study

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International Journal of Ophthalmology(English edition) 2016年第12期9卷 1756-1760页

作者： meng Xin Yue-Rong Gong Shan-Hao Jiang Chun-hua dai Su-Xia Li Wei-Yun Shi Shandong University Jinan 250012 Shandong ProvinceChina Department of Ophthalmology Yantai Affiliated Hospital of Binzhou Medical University Yantai 264100 Shandong Province China Department of Ophthalmology Binzhou Medical University Hospital Binzhou 256603 Shandong Province China Shandong Eye Hospital Shandong Eye Institute Shandong Academy of Medical Sciences Jinan 250021 Shandong Province China

AIM： To summarize preoperative evaluation and outcome of corneal transplantation for limbal dermoids for ten ***： Eighty-five patients diagnosed with limbal dermoids and treated with corneal transplantation were analyzed retrospectively. All patients were further divided into two groups according to absence or presence of neovascularization surrounding the dermoids in the corneal stroma. Eighty-two eyes were treated with tumor excision combined with partial lamellar sclerokeratoplasty, and the other three eyes were performed by penetrating keratoplasty. The size and location of the tumor, the associated ocular and systemic anomalies, the depth of the corneal penetration of tumor tissues, the preoperative and postoperative best-corrected visual acuity （BCVA）, graft survival and cosmetic outcome, and surgical complications were recorded ***： The average age at surgery was 5.3y （range, 3mo-36y）. The mean size of dermoids was 6.1±1.6 mm. The 43.5% of eyes （37/85） were present with hair at the surface of the dermoid and 72.9% of dermoids were located inferotemporal of the eye. Amplyopia was present in 34.1% of patients （29/85） and 9.4% of patients （8/85） had lipodermoids. Eighteen patients suffered from Goldenhar’s syndrome with an accessory ear. The 75% of patients in group 1 had involvement of the corneal deep stroma down to Descemet’s membrane without involving it, but 71.4% of patients had Descemet’s membrane involvement in group 2. Preoperative BCVA ranged from counting fingers to 20/20. Postoperatively 81.1% had a BCVA of 20/800 or better. There was no significant difference between the post-surgical BCVA of the two groups （t=1.584, P〉0.05）. The grafts of 70.5% patients were present as 1＋ opacity, 21.1% as 2＋ opacity, 8.2% as 3＋ opacity and none as 4＋ opacity. Surgical complications included graft rejection, microperforation, prolonged reepithelialization, steroid glaucoma, interface neovascularization, and interface ***

关键词： limbal dermoids corneal transplantation neovascularization

New explicit algebraic stress and flux model for active scalar and simulation of shear stratified cylinder wake flow

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Science China(Technological Sciences) 2009年第9期52卷 2536-2546页

作者： hua ZuLin GU Li XING LingHang dai WenHong Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education College of Environmental Science&EngineeringHohai UniversityNanjing 210098China Yangtze River Scientific Research Institute Wuhan 430010China Centre for Water and Environment Queen’s UniversityKingstonOntarioK7L3N6Canada

On the numerical simulation of active scalar,a new explicit algebraic expression on active scalar flux was derived based on Wikstrm,Wallin and Johansson model (aWWJ model). Reynolds stress algebraic expressions were added by a term to account for the buoyancy effect. The new explicit Reynolds stress and active scalar flux model was then established. Governing equations of this model were solved by finite volume method with unstructured grids. The thermal shear stratified cylinder wake flow was computed by this new model. The computational results are in good agreement with laboratorial measurements. This work is the development on modeling of explicit algebraic Reynolds stress and scalar flux,and is also a further modification of the aWWJ model for complex situations such as a shear stratified flow.

关键词： active scalar explicit algebraic model scalar flux Reynolds stress thermal shear stratified cylinder wake flow numerical simulation

Synthesis and Crystal Structure of a Novel Manganese Coordination Polymer Constructed by 3,5-Dimethylbenzoic Acid with 4,4'-Bipyridine

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1213-1216页

作者： ZHANG Chun-hua CHEN Man-Sheng KUANG dai-Zhi Department of Chemistry and Materials Science Hengyang Normal University Hengyang 421008 China

A novel manganese coordination polymer [Mn（L）2（bipy）]n （HL = 3,5-dimethylbenzoic acid, 4,4＇-bipy = 4,4＇-bipyridine） has been synthesized by a hydrothermal method. The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 2.0996（8）, b = 1,1835（5）, c = 0.9958（4） nm, β = 110.161（5）°, V = 2,3229（16） nm^3, Z = 4, C28H26MnN2O4, Mr = 509.45, Dc= 1.457 g/cm^3,μ = 0.607 mm^-1, F（000） = 1060, Rim = 0.0566, R = 0.0334 and wR = 0.1078. In the crystal the manganese atom is six-coordinated by two nitrogen atoms from 4,4＇-bipy and four oxygen atoms from 3,5-dimethylbenzolate molecules, completing an octahedral geometry. The 4,4＇-bipy molecules bridge the infinite chain [Mn（L）2（bipy）]n to form a two-dimensional layer.

关键词： manganese coordination polymer hydrothermal synthesis crystal structure

Pancreatic duct stones in patients with chronic pancreatitis:surgical outcomes

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Hepatobiliary & Pancreatic Diseases International 2010年第4期9卷 423-427页

作者： Liu, Bo-Nan Zhang, Tai-Ping Zhao, Yu-Pei Liao, Quan dai, meng-hua Zhan, Han-Xiang Peking Union Med Coll Peking Union Med Coll Hosp Dept Gen Surg Beijing 100730 Peoples R China Chinese Acad Med Sci Beijing 100730 Peoples R China

BACKGROUND: Pancreatic duct stone (PDS) is a common complication of chronic pancreatitis. Surgery is a common therapeutic option for PDS. In this study we assessed the surgical procedures for PDS in patients with chronic pancreatitis at our hospital. METHOD: Between January 2004 and September 2009, medical records from 35 patients diagnosed with PDS associated with chronic pancreatitis were retrospectively reviewed and the patients were followed up for up to 67 months. RESULTS: The 35 patients underwent ultrasonography, computed tomography, or both, with an overall accuracy rate of 85.7%. Of these patients, 31 underwent the modified Puestow procedure, 2 underwent the Whipple procedure, 1 underwent simple stone removal by duct incision, and 1 underwent pancreatic abscess drainage. Of the 35 patients, 28 were followed up for 4-67 months. There was no postoperative death before discharge or during follow-up. After the modified Puestow procedure, abdominal pain was reduced in patients with complete or incomplete stone clearance (P>0.05). Steatorrhea and diabetes mellitus developed in several patients during a long-term follow-up. CONCLUSIONS: Surgery, especially the modified Puestow procedure, is effective and safe for patients with PDS associated with chronic pancreatitis. Decompression of intraductal pressure rather than complete clearance of all stones predicts postoperative outcome.

关键词： pancreatic duct stone chronic pancreatitis surgical management modified Puestow procedure

Mechanics of advanced fiber reinforced lattice composites

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Acta Mechanica Sinica 2010年第6期26卷 825-835页

作者： hua-Lin Fan Tao Zeng dai-Ning Fang Wei Yang College of Mechanics and Materials Hohai University Nanjing 210098China Key Laboratory for Advanced Building Materials of Sichuan Province Southwest University of Science and Technology Mianyang 621010China College of Civil Engineering and Architecture Harbin University of Science and TechnologyHarbin 150080China College of Engineering Peking University Beijing 100871China University Office Zhejiang University Hangzhou 310058China

Fiber reinforced lattice composites are lightweight attractive due to their high specific strength and specific *** the past 10 years,researchers developed three-dimensional（3D） lattice trusses and two-dimensional （2D） lattice grids by various methods including interlacing, weaving,interlocking,filament winding and molding hot- *** lattice composites have been applied in the fields of radar cross-section reduction,explosive absorption and heat-resistance. In this paper,topologies of the lattice composites, their manufacturing routes,as well as their mechanical and multifunctional applications,were surveyed.

关键词： Lattice composites Mechanical behaviors Fabrication Multifunction

Experimental Investigation on Ejector Performance Using R134a as Refrigerant

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Journal of Thermal Science 2019年第4期28卷 727-735页

作者： dai Zhengshu YU Bo LIU Pengpeng CHEN Guangming ZHANG hua School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China State Key Laboratory of Air-conditioning Equipment and System Energy Conservation Zhuhai 519070China Institute of Refrigeration and Cryogenics Zhejiang UniversityHangzhou 310027China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093China

Ejector refrigeration has the advantage of low capital cost,simple design,reliable operation,long lifespan and almost no *** only weakness is the low efficiency and its intolerance to deviations from design operation condition.R134 a used in ejector refrigeration system gives better performance in comparison with many other environmental friendly refrigerants as the generation temperature is from 75℃to 80℃.The present work experimentally investigated the on-design and off-design performance of the ejector with fixed geometry using R134 a as refrigerant,and cycle performance of the ejector refrigeration *** experimental prototype was constructed and the effects of primary flow inlet pressure,secondary flow inlet pressure and ejector back pressure on ejector performance and cycle performance were investigated *** operation conditions are:primary flow inlet pressure from 2.2 MPa to 3.25 MPa,secondary flow inlet pressure from 0.36 MPa to 0.51 MPa,ejector back pressure from 0.45 MPa to 0.67 *** were drawn from the experimental results,and the experimental data can be used for validation of theoretical model for both critical and subcritical mode.

关键词： ejector performance refrigeration R134a experiment