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Partial extinction, permanence and global attractivity innonautonomous n-species Lotka-Volterra competitivesystems with impulses

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Applied mathematics(A Journal of Chinese Universities) 2011年第2期26卷 161-176页

作者： HOU juan TENG Zhi-dong GAO shu-jing College of mathematics and Systems Science Xinjiang UniversityUrumqi 830046P.R.China Department of Applied mathematics Xinjiang University of Finance and EconomicsUrumqi830012P.R.China College of mathematics and Computer Science Gannan Normal UniversityGanzhou 341000P.R.China

In this paper, the qualitative properties of general nonautonomous Lotka-Volterran-species competitive systems with impulsive e？ects are studied. Some new criteria on thepermanence, extinction and global attractivity of partial species are established by used themethods of inequalities estimate and Liapunov functions. As applications, nonautonomous twospecies Lotka-Volterra systems with impulses are discussed.

关键词： Nonautonom ous Lotka-Volterra system Impulsive efects Competition Extinction Permanence Global attractivity.

Dynamics of traveling wave solutions to a highly nonlinear Fujimoto–Watanabe equation

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Chinese Physics B 2019年第4期28卷 51-55页

作者： Li-juan Shi Zhen-shu Wen Fujian Province University Key Laboratory of Computational Science School of Mathematical Sciences Huaqiao University

In this work, we apply the bifurcation method of dynamical systems to investigate the underlying complex dynamics of traveling wave solutions to a highly nonlinear Fujimoto–Watanabe equation. We identify all bifurcation conditions and phase portraits of the system in different regions of the three-dimensional parametric space, from which we present the sufficient conditions to guarantee the existence of traveling wave solutions including solitary wave solutions, periodic wave solutions, kink-like(antikink-like) wave solutions, and compactons. Furthermore, we obtain their exact expressions and simulations, which can help us understand the underlying physical behaviors of traveling wave solutions to the equation.

关键词： highly nonlinear Fujimoto–Watanabe equation dynamics traveling wave solutions bifurcations

Frictionless Multi-field Coupling Contact Problem for a Thermoelectric Layer Loaded by Two Rigid Punches

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Acta Mechanica Solida Sinica 2023年第2期36卷 282-292页

作者： Yali Zhang Hailiang ma juan Yang Shenghu Ding School of mathematics and Statistics Ningxia UniversityYinchuan 750021China School of Ethnic Preparatory Education Ningxia UniversityYinchuan 750021China

In this paper,the thermo-electro-mechanical coupling contact problem of thermoelectric material with double punches is analyzed *** the Fourier cosine transform technique,the thermo-electro-elastic problem is transformed into three sets of singular integral equations,which are numerically solved by the Gauss–Chebyshev integral formula according to the unknown normal electric current density,normal energy flux and normal contact *** a rigid flat indenter,the results can be covered by the degradation results of two rigid flat *** numerical results reveal the interaction between two punches and the effect of thermoelectric load on the indentation *** interaction between the two punches reduces the contact pressure at the inner edge of the indenter as the thermoelectric load increases while increasing the stress singularity at the outer *** change of punches’spacing makes the singularity of normal stress at the inner and outer edges *** results provide an in-depth understanding of the multi-region contact damage mechanism of thermoelectric material.

关键词： Thermoelectric material Two rigid punches Interaction Analytical solutions

Kinetic study on desulfurization and denitrification using microwave irradiation over activated carbon

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Science China(Technological Sciences) 2011年第9期54卷 2321-2326页

作者： ma shuangChen YAO juan juan JIN Xin ZHANG Bo School of Environment North China Electric Power University Baoding 071003 China

Sulfur dioxide （SO2） and nitrogen oxide （NOx） in flue gas can be removed by combining microwave induced catalysis and adsorption on activated carbon. The reaction mechanisms of desulfurization and denitrification by microwave irradiation were analyzed based on the measurement of reaction products. Thermodynamic parameters for desulfurization and denitrification by thermal-carbon reduction were predicted according to the principles of thermodynamics. The experimental results indicated that the desulfurization and denitrification reaction processes include three reaction stages： slow reaction zone, transitional zone and rapid reaction zone. In high temperature zone, activation energies for the reduction of SO2 and nitrogen monoxide （NO） are 30.69 and 24.06 kJ mo1-1, respectively. This study shows that microwave can effectively enhance the removal of pollutants through its heating effect and the induced catalysis.

关键词： microwave desulfurization denitrification kinetics

Cloud Classification and Distribution of Cloud Types in Beijing Using Ka-Band Radar Data

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Advances in Atmospheric Sciences 2019年第8期36卷 793-803页

作者： juan HUO Yongheng BI Daren Lü shu DUAN Key Laboratory for Atmosphere and Global Environment Observation Chinese Academy of Sciences

A cloud clustering and classification algorithm is developed for a ground-based Ka-band radar system in the vertically pointing mode. Cloud profiles are grouped based on the combination of a time–height clustering method and the k-means clustering method. The cloud classification algorithm, developed using a fuzzy logic method, uses nine physical parameters to classify clouds into nine types: cirrostratus, cirrocumulus, altocumulus, altostratus, stratus, stratocumulus, nimbostratus,cumulus or cumulonimbus. The performance of the clustering and classification algorithm is presented by comparison with all-sky images taken from January to June 2014. Overall, 92% of the cloud profiles are clustered successfully and the agreement in classification between the radar system and the all-sky imager is 87%. The distribution of cloud types in Beijing from January 2014 to December 2017 is studied based on the clustering and classification algorithm. The statistics show that cirrostratus clouds have the highest occurrence frequency(24%) among the nine cloud types. High-level clouds have the maximum occurrence frequency and low-level clouds the minimum occurrence frequency.

关键词： clouds clustering algorithm classification algorithm radar cloud type

Crystalline,Rheological and Mechanical Enhancement in PBAT/PPC/Silica Nanocomposites with Double Percolation Network

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Chinese Journal of Polymer Science 2022年第11期40卷 1482-1492页

作者： You-Mei ma Feng-Xiang Gao shu-Ling Zhang College of Chemistry Jilin UniversityChangchun130012China Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China

Nanocomposites of blends of biodegradable poly(butylene adipate-co-terephthalate)(PBAT)and sustainable poly(propylene carbonate)(PPC)with nanosilica were prepared by melt compounding ***/PPC blend was partially miscible system with sea-island structure,and nanosilica particles were selectively dispersed in the continuous phase PBAT matrix to form the double percolation *** introduction of nanosilica into PBAT/PPC blend reduced the size of dispersed PPC phase,promoted the crystallization of PBAT in the nanocomposites,and increased the storage modulus of the *** study of rheological behaviors indicated that the double percolation network was formed at the nanosilica loading of 5 wt%,as a result,the nanocomposites exhibited the solid-like viscoelastic behavior and their relaxation time was *** the increase of the nanosilica content,the PBAT/PPC/silica nanocomposites displayed increased Young's modulus and yield strength.

关键词： Nanocomposites Selective dispersion Double percolation Enhanced properties

急性冠脉综合征同病异证与TM、ICAM-1、Lp-PLA2水平的相关性研究

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中国中西医结合杂志 2018年第5期38卷 530-533页

作者：许振业柳景华刘建勋王韶屏任钧国程姝娟马彩云马芹吕媛吴铮彭红玉赵烨婧首都医科大学附属北京安贞医院心内科北京市心肺血管疾病研究所北京100029 北京市大兴区人民医院心内科北京102600 中国中医科学院西苑医院基础医学研究所北京100091 中国医科大学航空总医院心内科北京100012

目的比较急性冠脉综合征(ACS)气滞血瘀证、气虚血瘀证不同证型蛋白表达水平,为ACS辨证分型提供客观依据。方法 60例2015年7月—2016年2月于首都医科大学附属北京安贞医院心内科住院,临床诊断为ACS并经皮冠状动脉造影术证实为冠心病拟行... 详细信息

目的比较急性冠脉综合征(ACS)气滞血瘀证、气虚血瘀证不同证型蛋白表达水平,为ACS辨证分型提供客观依据。方法 60例2015年7月—2016年2月于首都医科大学附属北京安贞医院心内科住院,临床诊断为ACS并经皮冠状动脉造影术证实为冠心病拟行经皮冠状动脉介入治疗的患者,其中气滞血瘀证组29例,气虚血瘀证组31例。检测血清高敏C反应蛋白(hs-CRP)、血清血栓调节蛋白(TM)、可溶性细胞间黏附分子(ICAM-1)、脂蛋白相关磷脂酶A2(Lp-PLA2)水平变化,并记录血瘀证计分及冠脉病变程度评分(Gensini评分)。结果与气滞血瘀证组比较,气虚血瘀证组TM、ICAM-1水平升高(P=0.039,P=0.026);两组hs-CRP、Lp-PLA2水平、Gensini评分、血瘀证各项计分及总分比较差异均无统计学意义(均P>0.05)。ACS气滞血瘀及气虚血瘀证患者hs-CRP、TM、ICAM-1、Lp-PLA2水平及血瘀证总计分均与Gensini评分无相关性(P>0.05)。结论血清TM、ICAM-1可考虑作为ACS患者气滞血瘀证、气虚血瘀辨证分型的生物学标志物。

关键词：冠心病气滞血瘀证气虚血瘀证血栓调节蛋白可溶性细胞间黏附分子 Gensini评分

Strange Meson Photo-production and Its Associated Radiative Capture on Proton in Low-Energy QCD Lagrangian

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Communications in Theoretical Physics 2006年第3X期46卷 493-500页

作者： ZHOU Li-juan ma Wei-Xing Collaboration Group of Hadron Physics and Non-perturbative QCD Study Guangxi University of Technology Liuzhou 545006 China Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918 Beijing 100049 China

Based on the low energy QCD Lagrangian theory and the crossing symmetry relation, strange meson photoproduction and its associated radiative capture on the proton are investigated in the [SUSF（6） × O（3）]sym . × SUc（3） quark mode/of baryon structure with only one same input parameter, the only strong coupling constant aM. Calculations for the cross sections, p-polarization of γ ＋ P → K^＋＋ A reaction and the branching ratios for K^- radiative capture of K^- ＋ p →　γ ＋ Y with Y = A, ∑^0 are performed. Good agreements to data are obtained and the results show that, compared to traditional phenomenological models, the low energy QCD Lagrangian theory provides a successful, unifled description of the strange meson photo-production and its associated radiative capture.

关键词： low-energy QCD Lagrangian quarks and gluons quark structure of baryon strange meson photoproduction K^- meson radiative capture

A New and Efficient Synthesis of 2H-3, 1-Benzoxazine Compounds

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Chinese Chemical Letters 2005年第11期16卷 1424-1426页

作者： Jia Rong LI shu Ling ma School of Chemical Engineering and Environment Beijing Institute of Technology Beijing 100081

2H-3, 1-Benzoxazine derivatives were synthesized by cyclocondensation of 5-nitro-2- cyanoaniline with relative ketone or aldehyde with ZnCl2 as a catalyst. This is a new efficient synthetic route of 2H-3, 1-benzoxazin... 详细信息

关键词： 2H-3 1-Benzoxazine cyclocondensation synthesis