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B_c Meson Studies

高能物理与核物理 2002年第Z1期26卷 1-10页

作者： cHANG chao-Hsi (Institute of Theoretical Physics, c.inese ac.demy of sciences, Beijing 100080, china) Inst. of Theor. Phys. Chinese Acad. of Sci. Beijing 100080 China

Our studies on the meson Bc arc briefly *** decays of the meson Bc to a P-wave charmonium Xc or hc are reported comparatively precisely because they are fresh

关键词：高能物理核物理增刊张肇西 B_c Meson Studies Rev

A note on the tree decompositions of graphs

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c.inese Science Bulletin 1997年第23期42卷 1948-1952页

作者： SHI MinyongInstitute of Software, c.inese ac.demy of sciences, Beijing 100080, china Institute of Software Chinese Academy of Sciences Beijing China

IN this note all graphs are undirected, finite and simple. For a subgraph H of G,ε（H） andμ（H） denote the number of edges in H and the number of cycles in H respectively. H[X]denotes the subgraph of H induced by X. Given two disjoint subsets X and Y of V（G）, wewrite EG（X, Y）={xy∈E（G）|x∈X, y∈Y}. Sometimes EG（H, Y）=EG（V（H）,Y） is used for a subgraph H of G-Y. If T is a tree of G and e=uv∈G-E（T）with{u,v}V（T）, then T + e contains a unique cycle, denoted by c（T, e）.A tree-decomposition {T1, T2, …, Tk} of a graph G is a partition of E （G）, say,E（G）=E1 U E2 U…U Ek, such that for each i with 1≤i≤k, Ti=G[Ei] is a tree.

关键词： tree decomposition singular vertex maximal planar bipartite graph.

Global convergence of the Broyden's class of Quasi-Newton Methods with Nonmonotone Linesearch

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acta Mathematicae Applicatae Sinica 2003年第1期19卷 19-24页

作者： Da-chuan XuInstitute of Applied Mathematics, ac.demy of Mathematics and System sciences, c.inese ac.demy of sciences, Beijing 100080, china Institute of Applied Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China

Abstract In this paper, the Broyden class of quasi-Newton methods for unconstrained optimization is investigated. Non-monotone linesearch procedure is introduced, which is combined with the Broyden's class. Under the ... 详细信息

关键词： Keywords Quasi-Newton method Broyden class non-monotone linesearch global convergence unconstrained optimization

callus formation in relation to changes of the membrane ca^(2+) in the graft unions of Ginkgo biloba L.

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c.inese Science Bulletin 1998年第20期43卷 1732-1736页

作者： YANG Xiong and LI Zhengli (Lee c. L.) college of Life sciences, Peking University, Beijing 100871, china college of Life sciences Peking University Beijing China

The relationship between the callus formation and intracellular ca 2+ at the early stage of development of graft unions in Ginkgo biloba L. was investigated. On the second day after grafting, part of the undamaged living cells at the graft interface of the stock and scion in the regions of the cortex and pith began to dedifferentiate or divide. 8 d after grafting, a great number of callus cells were produced from the cortex and phloem, while callus bridges linking the stock with scion formed between the callus cells of the graft partners from the cortex. A membrane ca 2+ probe, chlortetracycline (cTc), was used to locate the intracellular ca 2+ distribution and it was found that the cortical and pith parenchyma cells were the first to show remarkably increased cTc ca 2+ fluorescence, suggesting that the cortical and other parenchyma cells play a leading role at the early stage of development of graft unions by earlier dedifferentiation and more rapid production of callus cells.

关键词： callus formation membrane ca 2+ graft union Ginkgo biloba.

APPROXIMATION ALGORITHM FOR MAX-BISEcTION PROBLEM WITH THE POSITIVE SEMIDEFINITE RELAXATION

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Journal of computational Mathematics 2003年第3期21卷 357-366页

作者： Da-chuan Xu Ji-ye Han(Institute of Applied Mathematics, ac.demy of Mathematics and System sciences, c.inese ac.demyof sciences, Beijing 100080, china) Institute of Applied Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences 北京 100080

Using outward rotations, we obtain an approximation algorithm for Max-Bisection problem, i.e., partitioning the vertices of an undirected graph into two blocks of equal cardinality so as to maximize the weights of crossing edges. In many interesting cases, the algorithm performs better than the algorithms of Ye and of Halperin and Zwick. The main tool used to obtain this result is semidefinite programming.

关键词： Approximation algorithm Max-Bisection problem Semidefinite programming Approximation ratio.

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专著:中美社科学术体系的比较与展望

东南学术 2024年第1期 103-113,248页

作者：黄宗智赵珊美国加利福尼亚大学洛杉矶校区历史系天津商业大学法学院

改革学术评价体系,是推动学术高质量发展的重要路径之一,对此,国外先进经验有一定参考价值。在社会科学学术体系中,美国形成了以投入三四年的博士学位论文为基础、再加上六七年的后续研究的重量级专著传统。它固然存在广泛偏重主观理论... 详细信息

改革学术评价体系,是推动学术高质量发展的重要路径之一,对此,国外先进经验有一定参考价值。在社会科学学术体系中,美国形成了以投入三四年的博士学位论文为基础、再加上六七年的后续研究的重量级专著传统。它固然存在广泛偏重主观理论过于客观经验研究,偏重建构理想化的、逻辑上前后一贯的理论模式的弱点,但奠定了其在国际社科学术领域的重要地位。中国的博士学位论文制度在实际运作中则表现出深层的矛盾,没有形成较为重量级专著传统,因此使中国自身的学术水平提升受到一定限制。目前的中国社科学术体系亟须改革,需要从国家层面鼓励结合中国实际的重量级经验研究与新型社科理论的专著,来塑造具有中国主体性的专著体系。

关键词：中美专著环境美国的专著传统中国的社科学术体系新型社科理论创建

A note on noncommutative moment problems

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Science china Mathematics 2005年第8期48卷 1144-1151页

作者： MA Xiujuan School of sciences, Hebei University of Technology, Tianjin 300130, china Mathematics Institute, ac.demy of Mathematics and Systems Science, c.inese ac.demy of sciences, Beijing 100080, china 1. School of sciences Hebei University of Technology 300130 Tianjin China 2. Mathematics Institute Academy of Mathematics and Systems Science Chinese Academy of Sciences 100080 Beijing China

Noncommutative moment problems for c*-algebras are studied. We generalize a result of Hadwin on tracial states to nontracial case. Our results are applied to obtain simple solutions to moment problems on the square and the circle as well as extend the positive unital functionals from a (discrete) complex group algebra to states on the group c*-algebra.

关键词： moment, free product, state, group c*-algebra.

Spatial Variability of Soil Properties at capulin Volcano,New Mexico,USA:Implications for Sampling Strategy

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Pedosphere 2010年第2期20卷 185-197页

作者： D.c.WEINDORF School of Soil Plant and Environmental SciencesLouisiana State University

Non-agricultural lands are surveyed sparsely in ***,soils in these areas usually exhibit strong spatial variability which requires more samples for producing acceptable *** Volcano National Monument,as a typical sparsely-surveyed area,was chosen to assess spatial variability of a variety of soil properties,and furthermore,to investigate its implications for sampling *** hundred and forty one composited soil samples were collected across the Monument and the surrounding *** properties including pH,organic matter content,extractable elements such as calcium (ca),magnesium (Mg),potassium (K),sodium (Na),phosphorus (P),sulfur (S),zinc (Zn),and copper (cu),as well as sand,silt,and clay percentages were analyzed for each *** of all properties were constructed,standardized,and compared to estimate the spatial variability of the soil properties in the *** on the similarity among standardized semivariograms,we found that the semivariograms could be generalized for physical and chemical properties,*** generalized semivariogram for physical properties had a much greater sill value (2.635) and effective range (7 500 m) than that for chemical *** sampling density (OSD),which is derived from the generalized semivariogram and defines the relationship between sampling density and expected error percentage,was proposed to represent,interpret,and compare soil spatial variability and to provide guidance for sample scheme *** showed that chemical properties exhibit a stronger local spatial variability than soil texture parameters,implying more samples or analysis are required to achieve a similar level of precision.

关键词： generalized semivariogram GIS optimal sampling density sampling design

Net effect of air pollution controls on health risk in the Beijing-Tianjin-Hebei region during the 2022 winter Olympics and Paralympics

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Journal of Environmental sciences 2024年第1期135卷 560-569页

作者： changqing Lin Peter K.K.Louie Alexis K.H.Lau Jimmy c.H.Fung Zibing Yuan Minghui Tao Xuguo Zhang Md.Shakhaoat Hossain chengcai Li Xiang Qian Lao Division of Environment and Sustainability The Hong Kong University of Science and TechnologyHong KongChina Environmental Protection Department Hong Kong Government SARHong KongChina Department of civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina Guangdong-Hongkong-Macao Joint Laboratory of collaborative Innovation for Environmental Quality The Hong Kong University of Science and TechnologyHong KongChina Department of Mathematics The Hong Kong University of Science and TechnologyHong KongChina School of Environment and Energy South China University of TechnologyGuangzhou 510006China Hubei Key Laboratory of critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China Department of Public Health and Informatics Jahangirnagar UniversityDhaka 1342Bangladesh Department of Atmospheric and Oceanic sciences School of PhysicsPeking UniversityBeijing 100871China Jockey club School of Public Health and Primary care The Chinese University of Hong KongHong KongChina

Due to the non-linearity in ozone(O_(3))formation,reducing the emission of nitrogen oxides(NO_(x))may increase O_(3) *** the counteractive O_(3) response to NO_(x) reduction,overall impact of air pollution controls can be ambiguous when the assessments focus on the changes in pollutant *** this study,a risk-based method was used to gauge the net effect of air pollution controls on mortality risk in the Beijing–Tianjin–Hebei(BTH)region during the 2022 Winter Olympics and Paralympics(WOP).This mega-event presents a unique opportunity to investigate the efficacy of deep cuts in pollutant *** show that O_(3) concentrations greatly increased as nitrogen dioxide(NO_(2))concentrations decreased in the *** to the active photochemical formations,O_(3) became the dominant pollutant that affected human health during the *** the substantial O_(3) increases,the health benefits of NO_(2) reductions overwhelmed the adverse health effects of O_(3) increases in most regions of the BTH(at 81 out of 112 stations).After considering the impacts of particulate matter,the integrated health risk of air pollution mixtures declined almost everywhere in the *** results underscore the great necessity of changing the assessment paradigm of pollution control from using concentration-based methods to using risk-based *** with the carbon neutrality policy,stringent control of NO_(x)emission from combustion sources is a promising way to achieve synergistic control solutions for air pollution and climate change.

关键词： Ozone Nitrogen dioxide Health risk carbon neutrality Mega-events