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Experimental test of a new neutron threshold detector and its application

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Nuclear Science and Techniques 2002年第3期13卷 149-155页

作者： LI Gui-Sheng, ZHANG Tian-Mei, SU You-Wu, LI Shu-Wei(institute of Modern physics, the {2. academy of Sciences, lanzhou 730000) institute of Modern physics the Chinese Academyo f Sciences Lanzhou 730000 institute of Modern physics the Chinese Academyo f Sciences Lznahou 730000

The possibility of using 2.9Bi as a new threshold detector to measurc high-energy neutrons was investigated for the first time. At the same time the experiment measured successfully the emitted neutron fiuence rate, energy spectrum and dose equivalent rate distributions in the heavy ion target area using a detector complex including 2.9Bi, 115In, 2.A1, 19F and 12. samples.

关键词：阈探测器中子谱实验

Dynamic calculation model and seismic response for frame supporting structure with prestressed anchors

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Science china(Technological Sciences) 2010年第7期53卷 1957-1966页

作者： DONG JianHua1’2. ZHU YanPeng1, ZHOU Yong1 & MA Wei2.1 College of Civil Engineering, lanzhou University of Technology, lanzhou 730050, {2. 2.State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of Sciences, lanzhou 730000, {2. 1. College of Civil Engineering Lanzhou University of Technology Lanzhou 730050 China2. State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed. The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope. The lateral displacement of frame and soil is nearly in phase. The movement characteristic satisfies the theory of elastic foundation beam. The frame is treated with elastic foundation beam in this model. The influence of prestressed anchors is simplified as linear spring and damped system related with velocity. Under the condition of horizontal earthquake excitation, the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration. This method is applied to a case record for illustration of its capability, in order to verify the method, 3D nonlinear FEM (ADINA) is used to analyze the seismic performance of this case, the comparative results show that the design and the analysis are safe and credible by using the proposed method. The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors.

关键词： frame supporting structure with prestressed anchor slope dynamic calculation model seismic performance seismic design

Control of atmospheric CO_2.concentrations by 2.50: A calculation on the emission rights of different countries

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Science china Earth Sciences 2009年第10期52卷 1447-1469页

作者： DING ZhongLi1, DUAN XiaoNan2. GE QuanSheng3 & ZHANG ZhiQiang4 1 institute of Geology and Geophysics, {2. academy of Sciences, Beijing 10002., china 2.The General Office of {2. academy of Sciences, Beijing 100864, china 3 institute of Geographic Sciences and Natural Resources Research, {2. academy of Sciences, Beijing 100101, china 4 The {12. Branch of the National Science Library, the Scientific Information Center for Resources and Environment, lanzhou 730000, china institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China The General Office of chinese academy of Sciences Beijing 100864 China institute of Geographic Sciences and Natural Resources Research Chinese Academy

This paper is to provide quantitative data on some critical issues in anticipation of the forthcoming international negotiations in Denmark on the control of atmospheric CO2.concentrations. Instead of letting only a small number of countries dominate a few controversial dialogues about emissions reductions, a comprehensive global system must be established based on emissions allowances for different countries, to realize the long-term goal of controlling global atmospheric CO2.concentrations. That a system rooted in "cumulative emissions per capita," the best conception of the "common but differentiated responsibilities" principle affirmed by the Kyoto Protocol according to fundamental standards of fairness and justice, was demonstrated. Based on calculations of various countries' cumulative emissions per capita, estimates of their cumulative emissions from 1900 to 2.05, and their annual emissions allowances into the future (2.06―2.50), a 470 ppmv atmospheric CO2.concentration target was set. According to the following four objective indicators―total emissions allowance from 1900 to 2.50, actual emissions from 1900 to 2.05, emissions levels in 2.05, and the average growth rate of emissions from 1996 to 2.05―all countries and regions whose population was more than 300000 in 2.05 were divided into four main groups: countries with emissions deficits, countries and regions needing to reduce their gross emissions, countries and regions needing to reduce their emissions growth rates, and countries that can maintain the current emissions growth rates. Based on this proposal, most G8 countries by 2.05 had already expended their 2.50 emissions allowances. The accu-mulated financial value based on emissions has reached more than 5.5 trillion US dollars (2. dollars per ton of CO2.. Even if these countries could achieve their ambitious emissions reduction targets in the future, their per capita emissions from 2.06 to 2.50 would still be much higher than those of developing coun

关键词： international negotiations on climate change cumulative emissions per capita emission allowance

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, {2. academy of Sciences, lanzhou 730000, china 2. institute of physics, {2. 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.

Analysis of products of thymine irradiated by ^(18)O^(8+) ion beam in N_2. saturated aqueous solution

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Nuclear Science and Techniques 1999年第3期10卷 180-183页

作者： CAI Xichen WEI Zengquan LI Wenjian LIANG Jianping LI Qiang (institute of Modern physics, the {2. academy of Sciences, lanzhou 730000) institute of Modern physics Chinese Academy of sciences Lanzhou 730000 China

Some methods of capillary gas chromatography, such as GC, GC-MS,GC-FT-IR, are used to analyze the products of thymine irradiated by 18O8+ ion beam in N2. saturated aqueous solution. From the results of GC-MS the molecular weight of products can be determined, and from the results of GC-FT-IR some molecular structure information of products can be obtained. By this way the products,5,6-Dihydrothyndne, 5-Hydroxyl-5-Methylhydantoin, 5-Hydroxyl-6-Hydrothymine, 5-Hydro-6-Hydroxylthymine, 5-Hydroxymethyluracil, Trans-Thymine glycol, Cis-Thymine glycol and dimers are determined without separation of them from samples. Though these products are as same as those products of thymine irradiated by γ rays in N2. saturated aqueous solution, the mechanism of thymine irradiated by heavy ion beam in aqueous solution is different from that by γ rays. The main products of thymine irradiated by 18O8+ ion beam in N2. saturated aqueous solution are hydroxyl adducts at 5-6 band of thymine, while the main products of thymine irradiated by γ ray in N2. saturated aqueous solution are dimers of thymine.

关键词： ^18O^8+离子束辐照胸腺碱 N2.饱和水溶液

EMPLOYMENT OF SPIN TRAPPING TECHNIQUE TO THE STUDY OF PHOTOCATALYTIC DEHYDROGENATION MECHANISM OF ALCOHOL IN AQUEOUS SOLUTION

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分子催化 1989年第S1期3卷 15-21页

作者： Jin Zhensheng, LiQinglin, Feng Liangbo, GuXiaofeng (lanzhou institute of {2. physics, chinese academy of Sciences, lanzhou, china)

Spin trapping technique was employed to study the mechanism of photocatalyticdehydrogenation of alcohol during in situ irradiation of Rh2.3/CdS powder which is sus-pended in aqueous aicohol *** for production of ·OH ... 详细信息

Spin trapping technique was employed to study the mechanism of photocatalyticdehydrogenation of alcohol during in situ irradiation of Rh2./sub>O3/CdS powder which is sus-pended in aqueous aicohol *** for production of ·OH radical is presentedand the rate of·OH radical formation corresponds to the rate of H2./sub> *** the ba-sis of the above results,it is suggested that water cleavage is an intermediate step in this reac-tion.

关键词： irradiation alcohol trapping SPIN cleavage operated visible Intermediate remarkable ethanol

Development of a chinese land data assimilation system:its progress and prospects

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Progress in Natural Science:Materials International 2007年第8期17卷 881-892页

作者： Li Xin~(1**) Huang Chunlin~1 Che Tao~1 Jin Rui~1 Wang Shugong~l Wang Jiemin~1 Gao Feng~1 Zhang Shuwen~2.Qiu Chongjian~2.Wang Chenghai~2.(1.Cold and Arid Regions Environmental and Engineering Research institute,chinese {2. of Sciences,lanzhou 730000,china 2.College of Atmospheric Sciences,lanzhou University,lanzhou 730000,china) [a]Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou China [b]College of Atmospheric Sciences Lanzhou University Lanzhou China

The objective of land data assimilation is to merge multi-source observations into the dynamics of land surface model for improving the estimation of land surface *** have developed a land data assimilation system for china's land *** this sys- tem,the Common Land Model and Simple Biosphere Model 2.are used to simulate land surface *** radiative transfer models of thawed and frozen soil,snow,lake,and vegetation are used as observation operators to transfer model predictions into estimated bright- ness temperatures.A Monte-Carlo based sequential filter,the ensemble Kalman filter,is implemented as data assimilation method to inte- grate modeling and *** system is capable of assimilating passive microwave remotely sensed data such as special sensor mi- crowave/imager (SSM/I),TRMM microwave imager (TMI),and advanced microwave scanning radiometer enhanced for EOS (AMSR- E) and the conventional in situ measurements of soil and snow.A spatiotemporally consistent assimilated dataset for soil moisture,soil temperature,snow and frozen soil,with a spatial resolution of 0.2. degree and temporal resolution of one hour,has been *** paper introduces the development of chinese land data assimilation system and the progress made on data assimilation algorithms,land sur- face modeling,microwave remote sensing of land surface hydrological variables,and the preparation of atmospheric forcing *** dis- tinct characteristics and challenges of developing land data assimilation system and the perspectives for future development are also dis- cussed.

关键词： land data assimilation land surface model passive microwave remote sensing Kalman filter

Computational stability of the forced dissipative nonlinear atmospheric equations

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chinese Science Bulletin 1999年第10期44卷 949-952页

作者： LI Jianping and CHOU Jifan LASG , institute of Atmospheric physics , {2. academy of Sciences , Beijing 100080, china Department of Atmospheric Sciences , lanzhou University , lanzhou 730000, china Beijing Meteorological College, Beijing 100081, china LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Department of Atmospheric Sciences Lanzhou University Lanzhou China Beijing Meteorological College Beijing China

A new concept of computational quasi-stability (CQS) is introduced to study the computational stability (CS) of the forced dissipative nonlinear (FDN) evolution equations. Based on the concept, the CQS criterion of difference scheme of FDN atmospheric equations is obtained. So it provides the theoretical basis for designing the computational stable difference scheme of FDN atmospheric equations.

关键词： computational stability (CS) computational quasi-stability (CQS) operator equation difference scheme forced dissipative nonlinear (FDN) equations.

Ground State Structure of Hs Super-heavy Isotopes

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原子核物理评论 2009年第S1期26卷 175-180页

作者： MA Long1,ZHOU Xiao-hong1,ZHANG Hong-fei2.GAN Zai-guo1, LI Jun-qing1,3 (1 institute of Modern physics,{2. academy of Sciences,lanzhou 730000,china 2.School of Nuclear Science and Technology,lanzhou University,lanzhou 730000,china 3 Center of Theoretical Nuclear physics,National Laboratory of Heavy Ion Research Facility in lanzhou,lanzhou 730000,china) institute of Modern physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China institute of Modern physics Chinese Academy of SciencesLanzhou 730000China Center of Theoretical Nuclear physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China

The ground state properties of Hs nuclei studied in the framework of the relativistic mean field theory revealed that more stable isotopes are located on the proton abundant side of the chain. The last stable nucleus to the proton drip line is 2.6Hs. The most stable unknown Hs nucleus may be 2.8Hs. The density dependent delta interaction pairing is used to improve the BCS pairing correction,which results in more reasonable single-particle energy level distributions and nucleon occupation,and it is shown to be available to describe the properties of nuclei in the superheavy region.

关键词： superheavy nucleus nuclear structure pairing