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Homology roses and the D(2)-problem

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Science China Mathematics 2015年第8期58卷 1753-1770页

作者： jin XiFeng su Yang YU Li Department of Mathematics Nanjing University Institute of Mathematics Hua Loo-Keng Key Laboratory of MathematicsChinese Academy of Sciences Institute of Mathematical Science Nanjing University

For a commutative ring R with a unit, an R-homology rose is a topological space whose homology groups with R-coefficients agree with those of a bouquet of circles. In this paper, we study some special properties of the fundamental groups of R-homology roses and their covering spaces, from which we obtain some results supporting the Carlsson conjecture on free(Zp)ractions. In addition, we discuss how to search candidates of the counterexamples of Wall's D(2)-problem among R-homology roses and R-acyclic spaces and propose some candidates.

关键词： homology rose deficiency group cohomology Carlsson conjecture D(2)-problem gap efficiency Cockcroft property

Species identification of crested gibbons(Nomascus) in captivity in China using karyotyping-and PCR-based approaches

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Zoological Research 2018年第5期39卷 356-363页

作者： Wen-Hui Nie jin-Huan Wang Wei-Ting su Yu Hu Shui-Wang He Xue-long Jiang Kai He Kunming Institute of Zoology Chinese Academy of Sciences Kyoto University Museum Kyoto University

Gibbons and siamangs （Hylobatidae） are well-known for their rapid chromosomal evolution,which has resulted in high speciation rate within the *** the other hand,distinct karyotypes do not prevent speciation,allowing interbreeding between individuals in captivity,and the unwanted hybrids are ethically problematic as all gibbon species are endangered or critically ***,accurate species identification is crucial for captive breeding,particularly in China where studbooks are *** based on external morphology is difficult,especially for hybrids,because species are usually similar in *** this study,we employed G-banding karyotyping and fluorescence in situ hybridization （FISH） as well as a PCR-based approach to examine karyotypic characteristics and identify crested gibbons of the genus Nomascus from zoos and nature reserves in *** characterized and identified five karyotypes from 21 individuals of *** karyotypes and mitochondrial and nuclear genes,we identified three purebred species and three hybrids,including one F2 hybrid between *** and *** results also supported that *** and *** shared the same inversion on chromosome 7,which resolves arguments from previous *** results demonstrated that both karyotyping and DNA-based approaches were suitable for identifying purebred species,though neither was ideal for hybrid *** advantages and disadvantages of both approaches are *** results further highlight the importance of animal ethics and welfare,which are critical for endangered species in captivity.

关键词： F2 hybrid gibbon Fluorescence insitu hybridization Nomascus Pericentric inversion Species identification Animal welfare

Non-extensive statistical distributions of charmed meson production in Pb-Pb and pp(p)collisions

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Nuclear Science and Techniques 2021年第10期32卷 79-87页

作者： Yuan su Yong-Jie sun Yi-Fei Zhang Xiao-long Chen State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

The mid-rapidity transverse momentum spectra of charmed mesons in Pb–Pb and pp(p)collisions are analyzed using the Tsallis–Pareto distribution derived from non-extensive *** provide uniform descriptions of both small and large systems over a wide range of collision energies and hadron transverse *** establishing the relationship between the event multiplicity and Tsallis parameters,we observe that there is a signifi-cant linear relationship between the thermal temperature and Tsallis q parameter in Pb–Pb collisions at √sNN=2.76 TeV and 5.02 ***,the slope of the T–(q-1)parameter plot is positively correlated with the hadron *** addition,charmed mesons have a higher thermal temperature than light hadrons at the same q-1,indicat-ing that the charm flavor requires a higher temperature to reach the same degree of non-extensivity as light flavors in heavy-ion *** same fit is applied to the trans-verse momentum spectra of charmed mesons in pp(p)collisions over a large energy range using the Tsallis–Pareto *** is found that the thermal temperature increases with system energy,whereas the q parameter becomes saturated at the pp(p)limit,q-1=0.142±*** addition,the results of most peripheral Pb–Pb collisions are found to approach the pp(p)limit,which suggests that more peripheral heavy-ion collisions are less affected by the medium and more similar to pp(p)collisions.

关键词： Charmed meson Non-extensive statistics Tsallis-Pareto distribution QGP Heavy-ion collision

Lower Bounds of Distance Laplacian Spectral Radii of n-Vertex Graphs in Terms of Fractional Matching Number

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Journal of the Operations Research Society of China 2023年第1期11卷 189-196页

作者： jin Yan Yan Liu Xue-Li su School of Mathematical Sciences South China Normal UniversityGuangzhou510631GuangdongChina

A fractional matching of a graph G is a function f: E(G)→[0,1] such that for each vertex v, ∑eϵΓG(v)f(e)≤1.. The fractional matching number of G is the maximum value of ∑e∈E(G)f(e) over all fractional matchings f. Tian et al. (Linear Algebra Appl 506:579–587, 2016) determined the extremal graphs with minimum distance Laplacian spectral radius among n-vertex graphs with given matching number. However, a natural problem is left open: among all n-vertex graphs with given fractional matching number, how about the lower bound of their distance Laplacian spectral radii and which graphs minimize the distance Laplacian spectral radii? In this paper, we solve these problems completely.

关键词： Distance Laplacian Spectral radius Fractional matching number

Rhizopus microsporus lung infection in an immunocompetent patient successfully treated with amphotericin B:A case report

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World Journal of Clinical Cases 2021年第35期9卷 11108-11114页

作者： long Chen Yuan su Xian-Zhi Xiong Department of Respiratory and Critical Care Medicine Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina

BACKGROUND Rhizopus microsporus(***)lung infection is an invasive fungal disease with high mortality that is increasingly common in immunocompromised ***,it is very rare in immunocompetent ***,we present the case of a 19-year-old girl who developed *** lung infection without any known *** suMMARY The patient presented to our hospital because of hemoptysis and irritative cough without *** was first treated for community-acquired pneumonia until the detection of *** in bronchoalveolar lavage fluid by metagenomics next-generation sequencing(mNGS).After a combination therapy of intravenous inhalation and local airway perfusion of amphotericin B,she eventually recovered,with significant absorption of lung *** Early diagnosis and treatment are very important for pulmonary *** to fungal culture,mNGS is a relatively precise and convenient method to obtain pathogenic results.A combination therapy of intravenous inhalation and local airway perfusion of amphotericin B may be a promising strategy for the treatment of pulmonary mucormycosis in the future.

关键词： Rhizopus microsporus Immunocompetent patient Pulmonary mucormycosis Amphotericin B Case report

Numerical investigation and design of thin-walled complex section steel columns

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第2期12卷 131-138页

作者： su-qing HUANG Ju CHEN Wei-liang jin Department of Civil Engineering Zhejiang College of Construction Hangzhou 311200 China Department of Civil Engineering Zhejiang University Hangzhou 310058 China

A numerical investigation of thin-walled complex section steel columns with intermediate stiffeners was performed using finite element analysis. An accurate and reliable finite element model was developed and verified against test results. Veri-fication indicates that the model could predict the ultimate strengths and failure modes of the tested columns with reasonable accuracy. Therefore,the developed model was used for the parametric study. In addition,the effect of geometric imperfection on column ultimate strength and the effect of boundary conditions on the elastic distortional buckling of complex section columns were investigated. An equation for the elastic distortional buckling load of fixed-ended columns having different column lengths was proposed. The elastic distortional buckling load obtained from the proposed equation was used in the direct strength method to calculate the column ultimate strength. Generally,it is shown that the proposed design equation conservatively predicted the ultimate strengths of complex section columns with different column lengths.

关键词： Complex section column Distortional buckling Finite element method (FEM) Intermediate stiffener

EARLY CATARACT DETECTION BY DYNAMIC LIGHT SCATTERING WITH SPARSE BAYESIAN LEARNING

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Journal of Innovative Optical Health Sciences 2009年第3期2卷 303-313页

作者： su-long NYEO RAFAT R.ANSAR Department of Physics National Cheng Kung University TainanTaiwan 701ROC Bioscience and Technology Branch NASA Glenn Research Center at Lewis Field 21000 Brookpark Road ClevelandOH 44135USA

Dynamic light scattering(DLS)is a promising technique for early cataract detection and for studying cataractogenesis.A novel probabilistic analysis tool,the sparse Bayesian learning(SBL)algorithm,is described for reconstructing the most-probable size distribution ofα-crystallin and their aggregates in an ocular lens from the DLS *** performance of the algorithm is evaluated by analyzing simulated correlation data from known distributions and DLS data from the ocular lenses of a fetal calf,a Rhesus monkey,and a man,so as to establish the required efficiency of the SBL algorithm for clinical studies.

关键词： Cataract dynamic light scattering diagnostic algorithm sparse Bayesian learning(SBL).

Material Characterization of Ni Base Alloy for Very High Temperature Reactor

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Journal of Materials Science & Technology 2013年第12期29卷 1184-1190页

作者： Dong-jin Kim Gyeong-Geun Lee Dae Jong Kim su jin Jeong Nuclear Materials Division Korea Atomic Energy Research Institute

The generation of highly efficient electricity and the production of massive hydrogen are possible using a very high temperature reactor （VHTR） among generation IV nuclear power plants. The structural material for an intermediate heat exchanger （IHX） among numerous components should be endurable at high temperature of up to 950 °C during long-term operation. Impurities inevitably introduced in helium as a coolant facilitate the material degradation by corrosion at high temperature. In the present work, the surface reactions available under controlled impure helium at 950 °C were investigated based on the thermodynamics and the corrosion tests were performed in a temperature range of 850-950 °C during 10-250 h for commercial Alloy 617 as a candidate material for an IHX. Moreover, the mechanical property and microstructure for nickel-based alloys fabricated in laboratory were evaluated as a function of the processing parameters such as hot rolling and heat treatment conditions. From the reaction rate constant obtained from an impure helium control system for a material evaluation, it was predicted that the outer oxide layer thickness, internal oxide depth, and carbide- depleted zone depth reach about 116, 600 and 1000 μm, respectively when Alloy 617 is exposed to an impure helium environment at 950 ~C for 20 years. For Ni-Cr-Co-Mo alloy, subsequent annealing and a combination of cold working and subsequent annealing following solution annealing caused increases in the grain boundary carbide coverage and size. The angular distribution of the grain boundary as well as the carbide distribution was also changed leading to a consequent improvement of the mechanical property at 950 °C in air.

关键词： Nickel base alloy Intermediate heat exchanger High temperature reactor Corrosion Mechanical property

Effect of friction on the contact stress of a coated polymer gear

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Friction 2020年第6期8卷 1169-1177页

作者： su-Min BAE Kuk-jin SEO Dae-Eun KIM Department of Mechanical Engineering Yonsei UniversitySeoul 03722Republic of Korea

Polymer gears are used extensively in various ***,durability issues have been emerging because of friction at gear tooth contact *** extend the lifetime of polymer gears,a low-frictional coating has been considered as a possible *** this study,a finite element simulation method was performed to investigate the contact stress between a pair of coated polymer *** simulation included various friction coefficients(COFs)for studying the effects of friction during the *** results revealed that the friction causes the contact stress to shift over the roll angle,which is attributed to the direction of the sliding friction based on a free-body *** also investigated the effects of coating and found that a thin coating has little effect on the bulk deformation behavior of the ***,the stress distribution in the coating at the pitch point was investigated as the COF *** zero friction,three notable stress regions were observed:1)the center of the surface,2)the end of the contact,and 3)the overall contact *** COF was increased in the micro-slip region of the contact interface,both tensile and compressive stresses in the coating *** study provides significant aid to engineers for understanding the stress response of the coating applied to polymer gears to achieve an optimal design.

关键词： coating contact stress finite element method(FEM) friction polymer gear