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Effects and underlying mechanisms of damming on carbon and nitrogen cycles and transport in rivers of Southwest China:project introduction

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Acta Geochimica 2017年第4期36卷 577-580页

作者： hua-yun Xiao State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesLincheng West Road(Jinyang)99Guiyang 550081GuizhouChina Institute of Surface-Earth System Science Tianjin UniversityTianjin 300072China

Southwest China is the primary area for damming rivers to produce hydroelectric energy and store *** damming has changed hydrodynamic,chemical,and biological processes,which are related to sinks and sources of greenhouse gases and carbon and nitrogen fluxes of different ***,I provide an introduction to a river damming-related foundation,the National Key R&D Program of China(2016YTA0601000).Supported by the foundation,we carried out research on multiprocesses/multi-interfaces of carbon and nitrogen biogeochemical cycles in a dammed river system and have produced important results,as presented in this issue of the journal.

关键词： Damming Carbon and nitrogen cycles Southwest Chinese rivers

Predictions of γ(4S)→h_b(1P,2P)π^+π^- transitions

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Chinese Physics C 2020年第2期44卷 42-50页

作者： yun-hua Chen School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China

We study the contributions of intermediate bottomonium-like Zb states and the bottom meson loops in the heavy quark spin flip transitionsγ(4 S)→hb(1 P,2 P)π+π-.Depending on the constructive or destructive interferences between the Zb-exchange and the bottom meson loops mechanisms,we predict two possible branching ratios for each process:BRγ(4 S)→hb(1 P)π+π-≈(1.***.40.8×10^-6)or(0.5-0.20.5×10^-6),and BRγ(4 S)→(2 P)π+π-≈(7.1-1.1+1.7×10^-10)or(2.4-0.10.2×10^-10)).The contribution of the bottom meson loops is found to be considerably larger than that of the Zbexchange in the T(4 S)→hb(1 P)ππtransitions,while its decay rates are not comparable to those of heavy quark spin conservedγ(4 S)→γ(1 S,2 S)ππ*** also predict the contribution of the charm meson loops in the branch fractions ofΨ(3 S,4 S)→hc(1 P)ππ.

关键词： quarkonium exotic states nonrelativistic effective field theory

Fujita Type Conditions to Heat Equation with Variable Source

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Acta Mathematicae Applicatae Sinica 2017年第1期33卷 63-68页

作者： yun-xia LIU yun-hua WANG Si-ning ZHENG School of Mathematical Sciences Dalian University of Technology School of Mathematical Sciences Harbin Normal University

This paper studies heat equation with variable exponent ut = △u ＋ Up（x） 4- Uq in RN × （0, T）, where p（x） is a nonnegative continuous, bounded function, 0 〈 p- = infp（x） ≤ p（x） ≤ supp（x） = p＋. It is easy to understand for the problem that all nontrivial nonnegative solutions must be global if and only if max{p＋,q} ≤1. Based on the interaction between the two sources with fixed and variable exponents in the model, some Fujita type conditions are determined that that all nontrivial nonnegative solutions blow up in finite time if 0 〈 q ≤ 1 with p＋〉 1, or 1 〈 q 〈 1 ＋2/N. In addition, if q 〉 1 ＋2/N, then （i） all solutions blow up in finite time with 0 〈 p- ≤ p＋ ≤ 1 ＋2/N; （ii） there are both global and nonglobal solutions for p- ≤ 1 ＋ 2/N; and （iii） there are functions p（x） such that all solutions blow up in finite time, and also functions p（x） such that the problem possesses global solutions when p＋〈 1＋2/N 〈 p＋.

关键词： variable source Fujita type condition heat equation global solutions blow-up

Sub-additive Topological and Measure-theoretic Tail Pressures

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Acta Mathematica Sinica,English Series 2017年第12期33卷 1617-1631页

作者： Jing Lan PENG yun hua ZHOU College of Mathematics and Statistics Chongqing University Chongqing 401331 P. R. China

In this paper, we give some definitions of the topological tail pressures for sub-additive potentials and prove that they are equivalent if the potentials are continuous. Under some assumptions, we get a variational principle which exhibits the relationship between topological tail pressure and measure-theoretic tail entropy. Finally, we define a new measure-theoretic tail pressure for sub-additive potentials and some interesting properties of it are obtained.

关键词： Tail pressure variational principle sub-additive potential

Inverse Coefficient Problems for Nonlinear Elliptic Variational Inequalities

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Acta Mathematicae Applicatae Sinica 2011年第1期27卷 85-92页

作者： Run-sheng Yang yun-hua Ou Department of Mathematics Changsha University of Sciences and Technology Changsha 410076 China Department of Mathematics Hunan University of Technology Zhuzhou 412007 China

This paper is devoted to a class of inverse coefficient problems for nonlinear elliptic variational inequalities. The unknown coefficient of elliptic variational inequalities depends on the gradient of the solution and belongs to a set of admissible coefficients. It is shown that the nonlinear elliptic variational inequalities is unique solvable for the given class of coefficients. The existence of quasisolutions of the inverse problems is obtained.

关键词： Elliptic variational inequality inverse coefficient problem existence of quasisolution

Microemulsion Polymerization of Methyl Methacrylate

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Chemical Research in Chinese Universities 2001年第3期17卷 325-330页

作者： DAN Yi YANG yun-hua CHEN San-yu State Key Laboratory of Polymer Materials Engineering Department of Polymer Materials Science and EngineeringSichuan UniversityChengdu 610065P.R.China

The microemulsion polymerization of methyl methacrylate was studied. The effects of feeding modes on the structure and the properties of the obtained polymer microlatex were investigated by measuring the conversion, the transmittance and the refractive index of the latex, and by measuring the particle size, the molecular weight and the glass transition temperature (T_g) of the polymers. The results show that compared to the batch feeding mode, the semi-continuous feeding mode is more favorable to form a PMMA microlatex with a higher transmittance, a smaller particle size, a higher molecular weight and a higher T_g. And the obtained PMMA microlatex has a 30%—40% (mass fraction) polymer content, a 0. 03 emulsifier/water weight ratio, a 0. 05 emulsifier/monomer weight ratio and a 17 nm average particle diameter, which is very important for the industrialization of the microemulsion polymerization technique.

关键词： Microemulsion polymerization Methyl methacrylate Fedding mode Particle size

Assessment of bacterial biomass in the highly contaminated urban Nanming River,Guiyang,SW China

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Acta Geochimica 2017年第4期36卷 638-644页

作者： Hao Xiao hua-yun Xiao Pan Wu Resource and Environmental Engineering College Guizhou University State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of Sciences

High anthropogenic N loads and abundant bacteria are characteristic of highly contaminated urban *** better understand the dispersal and accumulation of bacteria, we determined contents and isotopic compositions of suspended particulate organic matter(SPOM) and bacteria in a highly contaminated urban river(the Nanming)and effluents in winter and summer of 2013. Relative to SPOM, bacterial biomass in the river was depleted in ^(13)C and ^(15)N and its C/N ratio was lower(δ^(13)C:-33.2% ± 3.1%; δ^(15)N:-1.5% ± 1.2%; C/N:4.8 ± 0.6), while effluents showed higher ^(13)C and ^(15)N contents and C/N ratios(δ^(13)C:-25% ± 2.1%; δ ^(15)N:-8.5% ± 1.1%; C/N: 8.1 ± 1.2). Source recognition of SPOM was based on carbon isotopes because they are conservative and distinct between end-members(effluent detritus and bacterial biomass). Using a mixing model,bacterial biomass in the river was calculated to account for <20% and <56% of bulk suspended particulate organic nitrogen in winter and summer, respectively. An N budget showed that bacterial N was a small proportion of total nitrogen(<7.4%) in the riverwater.

关键词： δ^13C δ^15C Bacterial biomass N budget Nanming River

Effects of single lance configuration on coal combustion process in tuyere from viewpoint of coal plume

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Journal of Iron and Steel Research International 2021年第7期28卷 785-798页

作者： yun-hua Zhou Ping Zhou Jia-yun Dan Hong-jie Yan Dong-ling Wu Valin Xiangtan Iron and Steel Corporation Xiangtan 411101HunanChina School of Energy Science and Engineering Central South UniversityChangsha 410083HunanChina

Pulverized coal utilization in the blast furnace is decided by the particle flow and combustion behaviors in the *** a specific operating condition,these behaviors are directly related to the lance configuration in the upstream tuyere *** on single straight lance,six types of single lance configurations were designed by assembling four parameters in different *** four parameters are the lance diameter,lance insertion angle,and the horizontal and vertical distances from the lance tip to the tuyere *** different lance configuration schemes applied,the pulverized coal combustion process in the lance-blowpipe-tuyere zone was *** simulation results regarding particle diffusion and combustion behaviors were characterized by three indicators from the viewpoint of a coal *** are the plume diffusion angle,diffusion uniformity,and the average plume temperature at the tuyere *** promote coal utilization,the values of these indicators under different configurations were analyzed,yielding two optimal *** first one is to reduce the lance length immersed in the blowpipe-tuyere by 100 *** other is to increase the horizontal distance from the lance tip to the tuyere outlet by 50 mm,and the insertion angle to 11° with the lance tip located at the tuyere *** findings can enhance the understanding of the influence mechanism of lance con-figuration on the coal utilization and provide guidelines for the design of new lance configurations.

关键词： Pulverized coal plume Particle dispersion Lance configuration Blast furnace

Improvement, Comparison, and Application of Field Measurement Methods for Grassland Vegetation Fractional Coverage

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Journal of Integrative Plant Biology 2005年第9期47卷 1074-1083页

作者： Xiao-Bing LI yun-Hao CHEN hua YANG yun-Xia ZHANG College of Resources Sciences and Technology Key Laboratory of Environmental Change and Natural Disaster of the Ministry of Education Beijing Normal University Beijing 100875 China

As one of the important vegetation parameters, vegetation fractional coverage （VFC） is more difficult to measure accurately among a good many parameters of plant communities. The temperate typical steppe in the north of China was chosen for investigation in the present study and a digital camera was used to measure herb community coverage in the field, adopting methods of ocular estimation, gridding measurement, visual interpretation, supervised classification, and information extraction of color spatial transformation to calculate the VFC of images captured by the digital camera. In addition VFC calculated by various methods was analyzed and compared VFC, enabling us to propose an effective method for measuring VFC using a digital camera. The results of the present study indicate that：（i） as two common useful and effective methods of measuring VFC with a digital camera, not only does the error of estimated values of visual estimation and supervised classification vary considerably, but the degree of automatization is very low and depends, to a great extent, on the manipulator; （ii） although the method of visual interpretation may assure the precision of the calculated VFC and enable the precision of results obtained using other methods to be determined, as far as large quantities of data are concerned, this method has the disadvantages of wasting time and energy, and the applications of this method are limited; （iii） the precision and stability of VFC calculated using the grid and node method are superior to those of visual estimation and supervised classification and inferior to those of visual interpretation, but, as for visual interpretation and supervised classification, gridding measurements are difficult to apply in practice because they are not time efficient; and （iv） in terms of the precision of calculation of the VFC, an information-extracting model based on an intensity, hue, saturation （IHS） color space-multi-component series segmentation strategy is s

关键词： color space transformation digital camera field measurement grassland vegetationfractional coverage.