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Reaction Chemistry of W-Mn/SiO2 Catalyst for the Oxidative Coupling of Methane

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Journal of Natural Gas Chemistry 2003年第1期12卷 1-9页

作者： Shuben LiState Key Laboratory for Oxo Synthesis and Selective Oxidation, lanzhou institute of Chemical physics, chinese academy of sciences, lanzhou 730000, china State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

Reaction chemistry of the OCM reaction on W-Mn/SiO_2 catalyst has beenreviewed in this account. Initial activity and selectivity, stability in a long-term reaction,reaction at elevated pressures and a modelling test in a stainless-steel fluidized-bed reactor showthat W-Mn/SiO_2 has promising performance for the development of an OCM process that directlyproduces ethylene from natural gas. A study on surface catalytic reaction kinetics and used catalyststructure characterization revealed a possible reason why C_2 and CO_x selectivity changed duringthe long-term reaction. Further improvement of the catalyst composition and preparation methodshould be a future direction of study on OCM reaction over W-Mn/SiO_2 catalyst.

关键词： W-Mn/SiO_2 catalyst oxidative coupling of methane elevated pressure methane

Mantle-derived rare-gas releasing features at the Tianchi volcanic area, Changbaishan Mountains

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chinese Science Bulletin 1997年第9期42卷 768-771页

作者： SHANGGUAN Zhiguan and SUN Mingliang1. institute of Geology, State Seismological Bureau, Beijing 100029, china 2. lanzhou institute of Geology, chinese academy of sciences, lanzhou 730000, china institute of Geology State Seismological Bureau Beijing China lanzhou institute of Geology Chinese Academy of Sciences Lanzhou China

TIANCHI volcano,Changbaishan Mountains isthe largest modern active volcano in East *** times strong volcanic erupting activ-ities occurred in the Cenozoic *** vol-canic activities have revived again in the *** investi... 详细信息

关键词： Tianchi volcanic area Changbaishan Mountains mantle-derived rare gas 3He/ 4He 40 Ar/36 Ar 4He/20 Ne 4He/40Ar isotope ratios.

The time and energy signals,counter plateau,energy resolution and gas gains performances of a new kind of micro-pattern gaseous detector-Micromegas

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Science china(Technological sciences) 2008年第12期51卷 2208-2212页

作者： ZHANG XiaoDong1,2,YANG HeRun1,XU HuShan2,DUAN LiMin2,HU BiTao1,LI ChunYan2 & LI ZuYu2 1 School of Nuclear Science and Technology,lanzhou University,lanzhou 730000,china 2 institute of modern physics,chinese academy of sciences,lanzhou 730000,china School of Nuclear Science and Technology Lanzhou University Lanzhou 730000 China institute of modern physics Chinese Academy of Sciences Lanzhou 730000 China

In present paper,a new Micromegas detector is developed,and its time and energy signals are obtained in the figure *** rising time of fast time signal is less than 2 ns due to the very fast collection of avalanche electrons,and the rising time of the energy pulse is about 100 ns,which is corresponding to the total collecting time of the electrons and ions in the avalanche *** counter plateau,energy resolution and the gas gains of the detector have been compared with other groups' experimental results and the Garfield simulation result.

关键词： micro-mesh gaseous structure time and energy signals energy resolution gas gain counter plateau

Charmed Baryon in Diquark Model

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原子核物理评论 2009年第S1期26卷 190-193页

作者： WANG Qing-wu1,3, ZHANG Peng-ming1,2(1 institute of modern physics, chinese academy of sciences, lanzhou 730000, china 2 Center of Theoretical Nuclear physics, National Laboratory of Heavy Ion Research Facility in lanzhou,lanzhou 730000, china 3 Graduate School of chinese academy of sciences, Beijing 100049, china) institute of modern physics Chinese Academy of SciencesLanzhou 730000China Graduate School of chinese academy of sciences Beijing 100049China institute of modern physics Chinese Academy of SciencesLanzhou 730000China Center of Theoretical Nuclear physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China

A diquark model is used to investigate single-charmed baryons. In this model,baryon is composed of two diquarks and an antiquark. Masses of lowest lying states with JP=1/2± are obtained. Baryons in our results are as heavy as other theoretic predictions and we suggest that the five-quark components should be considered in any three-quark model for studying the charmed baryons.

关键词： charm diquark pentaquark

Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

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Science china Earth sciences 2006年第11期49卷 1156-1169页

作者： WANG Genxu1,3 , LI Yuanshou2 , WU Qingbai2 & WANG Yibo3 1. institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of sciences, lanzhou 730000, china 3. Resource and Environment School, lanzhou University, lanzhou 730000, china 1. institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou 730000 China

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

The formation and stability of Si_(1-x)C_x alloys in Si implanted with carbon ions

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chinese Science Bulletin 2001年第3期46卷 200-204页

作者： WANG Yinshu, LI Jinmin, JIN Yunfan, WANG Yutian, SUN Guosheng & LIN Lanying1. Department of physics, Beijing Normal University, Beijing 100875, china 2. institute of Semiconductors, chinese academy of sciences, Beijing 100083, china 3. institute of modern physics, chinese academy of sciences, lanzhou 730000, china Department of physics Beijing Normal University Beijing China institute of Semiconductors Chinese Academy of Sciences Beijing China institute of modern physics Chinese Academy of Sciences Lanzhou China

Si1-xCx alloys of carbon (C) concentration between 0.6%-1.0% were grown in Si by ion implantation and high temperature annealing. The formation of Si1-xCx alloys under different ion doses and their stability during annealing were studied. If the implanted dose was less than that for amorphizing Si crystals, the implanted C atoms would like to combine with defects produced during implantation and it was difficult to form Si1-xCx alloys after being annealed at 850℃. With the increment of implanted C ion doses, the lattice damage increased and it was easier to form Si1-xCx alloys. But the lattice strain would become saturate and only part of implanted carbon atoms would occupy the substitutional positions to form Si1-xCx alloys as the implanted carbon dose increased to a certain degree. Once Si1-xCx alloys were formed, they were stable at 950℃, but part of their strain would release as the annealing temperature increased to 1 000℃. Stability of the alloys became worse with the increment of carbon

关键词： ion implantation Si1-xCx alloys stability of Si1-xCx alloys.

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邓小平新时期军队建设思想的伟大历史贡献

党的文献 2024年第4期 81-86页

作者： academy of Military sciences 中国人民解放军军事科学院

邓小平新时期军队建设思想,是新时期我们党领导筹划国防和军队现代化建设的根本依据和指导方针。邓小平科学判断战争与和平态势,实行国防和军队建设指导思想战略性转变,明确军队在国家大局中的定位与使命,探索和平时期军队建设新特点规... 详细信息

邓小平新时期军队建设思想,是新时期我们党领导筹划国防和军队现代化建设的根本依据和指导方针。邓小平科学判断战争与和平态势,实行国防和军队建设指导思想战略性转变,明确军队在国家大局中的定位与使命,探索和平时期军队建设新特点规律;调整积极防御的军事战略方针,将战略态势上的防御性同军事指导上的积极性统一起来,与时俱进创新军事战略指导;提出建设一支强大的现代化、正规化的革命军队总目标,指明人民军队建设发展的正确方向,为我军全面建设和长远发展提供行动纲领;坚定不移走中国特色精兵之路,科学处理军队建设中数量与质量的辩证关系,创新国防和军队建设发展模式。今天我们回顾和纪念邓小平的伟大军事贡献,关键是学习他在历史大转折时期领导筹划国防和军队现代化建设的新思路新方法,进而深入领会习近平主席在世界百年未有之大变局和中华民族伟大复兴战略全局交织激荡之际与时俱进带领全军进行的伟大理论创造和实践探索,坚定不移在习近平强军思想的科学指导下更加奋发有为地推进强军兴军事业。

关键词：邓小平新时期军队建设思想国防和军队现代化军事战略强军兴军

Impact of land-use change on hydrological processes in the Maying River basin, china

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Science china Earth sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3, ZHANG Yu2, LIU Guimin2 & CHEN Lin3 1. institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of sciences, lanzhou 730000, china 3. Resource and Environment School, lanzhou University, lanzhou 730000, china 1. institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou 730000 China

Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 35.32%, a drop in the maximum peak discharge of 35.77%, and mean discharge decreases in spring and autumn of 36.05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73%-81%, and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

Experimental study of electron capture excitation in collisions between Li-like N^(4+) ions and Na atoms

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chinese Science Bulletin 1997年第5期42卷 368-371页

作者： LIU Zhanwen, ZHOU Sixin, ZHANG Wen, ZHANG Xuezhen GUOXiaohong, WANG Youde, MA Xinwen, YANGZhihu, LIU Huiping, ZHAO Mengchun, YANG Feng, PAN Guangyan and LI Dawan1. institute of modern physics, chinese academy of sciences, lanzhou 730000, china 2. institute of physics, chinese academy of sciences, Beijing 100080, china institute of modern physics Chinese Academy of Sciences Lamhou China institute of Physia Chinese Academy of Sciences Beijing China

WITH the rapid development of the technique of ionized atoms, the charge states of atoms that can be obtained now are so high that the H-like U91+ ions and naked U92+ ions

关键词： single electron capture double electron capture emission cross section excited states.