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Improved formula of coronal magnetic field strength diagnostic

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chinese Science Bulletin 1997年第3期42卷 234-236页

作者： ZHOU AihuaPurple Mountian Observatory, chinese academy of sciences, Nanjing 210008, China Purple Mountian Observatory Chinese Academy of Sciences Nanjing 210008 China

CORONAL magnetic field is one of the most important physical quantities in the solar coronal atmosphere, and it is the key to an understanding of the origin and energy release of solar flares too. In most cases, microwave (MW) bursts are caused by reactions between mildly relativistic electrons and the coronal magnetic fields. So MW burst spectrum should embody the infor-

关键词： microwave burst spectrum coronal magnetic field.

Study of proton resonances in ^(18)Ne via resonant elastic scattering of ^(17)F+p and its astrophysical implication

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Science China(Physics,Mechanics & Astronomy) 2011年第S1期54卷 32-36页

作者： HE JianJun1, HU Jun1,2, XU ShiWei1, CHEN ZhiQiang1, ZHANG XueYing1, WANG JianSong1, YU XiangQing1, ZHANG LiYong1,2, LI Long1,2, YANG YanYun1,2, MA Peng1,2, ZHANG XueHeng1, HU ZhengGuo1, GUO ZhongYan1, XU Xing1,2, YUAN XiaoHua1, LU Wan1,2, YU YuHong1, ZANG YongDong1,2, TANG ShuWen1,2, YE RuiPing1,2, CHEN JinDa1,2, JIN ShiLun1,2, DU ChengMing1,2, WANG ShiTao1,2, MA JunBing1,2, LIU LongXiang1,2, BAI Zhen1,2, LEI XiangGuo1, SUN ZhiYu1, ZHANG YuHu1, ZHOU XiaoHong1, XU HuShan1, SU Jun3. LI ErTao3. WANG HongWei4. TIAN WenDong4.& LI XiangQing5 1 Institute of Modern Physics (IMP), chinese academy of sciences, Lanzhou 73.000, China 2 Graduate University of chinese academy of sciences, Beijing 10004., China 3.China Institute of Atomic energy (CIAE), Beijing 1024.3. China 4.Shanghai Institute of Applied Physics (SINAP), chinese academy of sciences, Shanghai 201800, China 5 School of Physics and State key {4. of Nuclear Physics and Technology, Peking University, Beijing 100871, China 1. Institute of Modern Physics (IMP) Chinese Academy of Sciences Lanzhou 730000 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. China Institute of Atomic Energy (CIAE) Beijing 102413 China4. Shanghai Institute of Applied Physics (SINAP) Chinese Academy of Sciences Shanghai 201800 China5. School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University Beijing 100871 China

The proton resonant properties in 18Ne, which determine the reaction rate of the key stellar 14.(α,p)17F reaction, have been studied by using a technique of proton resonant elastic scattering of 17F+p. A 4.22 MeV/nucleon 17F radioactive ion (RI) beam was produced via a projectile-fragmentation reaction, and separated by a Radioactive Ion Beam Line in Lanzhou (RIBLL). By bombarding a thick (CH2)n target, the energy spectra of the recoiled protons were measured by two ΔE-E silicon telescopes at the center-of-mass scattering angles of θc.m.≈175°±5°, θc.m.≈152°±8°, respectively. Several proton resonances in 18Ne were ob served clearly. A further R-matrix analysis of the experimental data is under way to determine the resonant parameters. The present work reports the preliminary results briefly.

关键词： resonant reaction reaction rate explosive burning accreting binary systems

The tricks plants use to reach appropriate light

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Science China(Life sciences) 2010年第8期53卷 916-926页

作者： CHAO DaiYin1 & LIN HongXuan2 1Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 4.907, USA 2National key laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological sciences, {3., Shanghai 20003., China 1. Department of Horticulture and Landscape Architecture Purdue University West Lafayette Indiana 47907 USA2. National Key Laboratory of Plant Molecular Genetics Shanghai Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200032 China

The perception of ambient light signals that produce a relevant response to ensure exposure to appropriate levels of light energy is vital for plants. In response to this, intricate molecular mechanisms to mediate light signaling have evolved in plants. Among the responses induced by light, seedling extension is a determining event for plant survival in darkness, especially in the initial stage of plant growth. Here we review previous studies and recent progress towards an understanding of light signaling that regulates seedling elongation. We focus on the three regions of the sunlight spectrum that primarily control seedling elongation, namely red/far-red light, blue/UV-A light and UV-B light, and summarize the four signaling pathways that correspond to the three effective spectra.

关键词： photomorphogenesis light signaling photoreceptors cell elongation cell division

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煤与生物质热重分析及动力学研究

燃料化学学报 2009年第5期37卷 538-545页

作者：武宏香李海滨赵增立中国科学院广州能源研究所中国科学院可再生能源与天然气水合物重点实验室广东省新能源和可再生能源研究开发与应用重点实验室广东广州510640 中国科学院研究生院北京100049

利用热重分析仪对稻秆、麦秆、木屑和煤单独及混合热解特性进行了研究。通过对不同混合比例热解与单独热解对比表明,混合热解中不同生物质起始热解温度、生物质挥发分最大析出温度、煤挥发分最大析出温度随着煤混合比例的变化呈规律性... 详细信息

利用热重分析仪对稻秆、麦秆、木屑和煤单独及混合热解特性进行了研究。通过对不同混合比例热解与单独热解对比表明,混合热解中不同生物质起始热解温度、生物质挥发分最大析出温度、煤挥发分最大析出温度随着煤混合比例的变化呈规律性变化。对混合热解实验数据与单独热解参数按混合比例后特性参数分析表明,混合热解导致固体产物产率提高。实验通过对稻秆两种方式的脱灰及脱挥发分处理后混合热解分析,脱挥发分稻秆与脱灰分稻秆对煤的热解都起到了促进作用,证明了生物质中的碱/碱土金属能促进煤在较低温度下热解,硅元素对热解速率起抑制作用。推测生物质与褐煤的共热解中存在协同作用。

关键词：生物质褐煤共热解

The Suitability of Using Leaf Area Index to Quantify Soil Loss under Vegetation Cover

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Journal of Mountain Science 2011年第4期8卷 564-570页

作者： ZHANG Wentai YU Dongsheng SHI Xuezheng WANG Hongjie GU Zhujun ZHANG Xiangyan TAN Manzhi State key laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of SciencesNanjing 21o0o8 China Graduate University of the chinese academy of sciences Beijing 100039 China School of Bio-Chemical and Environmental Engineering Nanjing Xiaozhuang University Nanjing 211171 China

Soil erosion by water under forest cover is a serious problem in southern China.A comparative study was carried out on the use of leaf area index(LAI) and vegetation fractional coverage(VFC) in quantifying soil loss under vegetation *** types of vegetation with varied LAI and VFC under field conditions were exposed to two rainfall rates(4. mm h-1 and 54.mm h-1) using a portable rainfall *** rate,sediment concentration and soil loss rate were measured at relatively runoff stable *** negative exponential relationship(p 3. and linear relationship(p 4. were obtained between LAI and sediment concentration,while no significant relationship existed between VFC and sediment *** mechanism by which vegetation canopy prevents soil loss was by reducing rainfall kinetic energy and sediment *** could better quantify such a role than ***,neither LAI nor VFC could explain runoff rate or soil loss *** must be taken when using LAI to quantify the role of certain vegetation in soil and water conservation.

关键词： Leaf area index(LAI) Runoff steady state Sediment concentration Simulated rainfall

Failure Mechanisms of Post-Earthquake Bedrock Landslides in Response to Rainfall Infiltration

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Journal of Mountain Science 2011年第1期8卷 96-102页

作者： WU Yong HE Siming LUO Yu LI Xinpo key laboratory of Mountain Hazards and Earth Surface Process Chinese Aeademy of Sciences Chengdu 610041 China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China

Among the triggering factors of postearthquake bedrock landslides, rainfall plays an important role. However, with slope variation, the mechanism of its effects on the failure of rock landslides is not dear. Here, from the viewpoint of fracture mechanics, and based on post-earthquake conditions, the mechanisms of crack propagation, water infiltration and development of the sliding surface were investigated. Then, according to the upper boundary theorem, the effects of water infiltrated into fractures on the stability of rock slopes were analyzed quantitatively. Finally, an example is presented to verify the theory. The results show that the propagation and coalescence of cracks and the lubrication of incipient sliding surfaces are the main causes of the failure of post-earthquake rock landslides in response to rainfall.

关键词： Post-earthquake Fracture infiltration Fracture mechanics Propagation and coalescence Upper boundary theorem energy theory Rock landslide

VISCOELASTIC BEHAVIOR OF THE NON-HOOKE DEFORMATION BEFORE YIELDING IN UNIAXIAL DRAWING OF AMORPHOUS POLY(ETHYLENE TEREPHTHALATE)

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chinese Journal of Polymer Science 2001年第4期19卷 399-405页

作者： Zhen-hua Yuan De-yan Shen Ren-yuan Qian Polymer Physics laboratory Center for Molecular Science, Institute of Chemistry chinese academy of sciences, Beijing 100080 China chinese Acad Sci Inst Chem Ctr Mol Sci Polymer Phys Lab Beijing 100080 Peoples R China

Viscoelastic behavior of the non-Hooke deformation of amorphous PET film before yield was investigated in the temperature region 74.80.5 degreesC around the glass transition temperature. The film specimen was drawn to yield point followed by unloading to zero stress, then the residual deformation was held constant; while the subsequent evolution of the stress was recorded. An induction period was found in the course of stress evolution followed by a stress step-increase. The induction period decreases with increasing drawing temperature with an activation energy of 1.10 MJ/mol.K, which is attributed to the time needed for the relaxation of rubbery deformation through cooperative internal rotations. At temperatures lower than 74.degreesC, there is no stress increase or the induction period becomes too long to be observed. Thus the nature of anelasticity in the non-Hooke region before yielding is attributed to stress induced rubbery deformation. The experimental results are interpreted in terms of Perez' theological model of a series connected Hooks spring and a Voigt element consisting of a parallel connected elastic spring and a dashpot.

关键词： pre-yield deformation PET uniaxial drawing non-Hooke deformation viscoelasticity stress induced rubbery deformation

Optimal speed of hypersonic cruise flight

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Theoretical & Applied Mechanics Letters 2011年第1期1卷 50-52页

作者： Jing Fan~(a)) key laboratory of High Temperature Gas Dynamics,Institute of Mechanics,chinese academy of sciences, Beijing {3.,China key laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

A coupling frame of speed gain and maintain was suggested to assess the flight performance of hypersonic cruise vehicles(HCV).The optimal cruise speed was obtained by analyzing the flight performance measured by the ratio of initial boost mass to generalized *** performance of HCVs based on rockets and air-breathing ramjets was studied and compared to that of a minimum-energy ballistic trajectory under a certain flight *** is concluded that rocket-based HCVs flying at the optimal speed are a very competitive choice at the current stage.

关键词： hypersonic cruise vehicle flight performance optimal cruise speed

A Self-consistent Calculation and an Anisotropic Wavelength Cut off energy of Spin-wave Spectrumin Magnetic Tunnel Junctions

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Journal of Materials Science & Technology 2001年第2期17卷 197-202页

作者： Xiufeng HAN State key laboratory of Magnetism, Institute of Physics, chinese academy of sciences, Beijing 100080, China Terunobu Miyazaki Department of Applied Physics, Graduate School of Engineering, Tohoku University, Aoba-yama 08, Sendai 980-8579, Japa chinese Acad Sci Inst Phys State Key Lab Magnetism Beijing 100080 Peoples R China Tohoku Univ Grad Sch Engn Dept Appl Phys Sendai Miyagi 9808579 Japan

Temperature dependence of tunnel magnetoresistance (TMR) ratio, resistance, and coercivity from 4.2 K to room temperature (RT), applied de bias voltage dependence of the TMR ratio and resistances at 4.2 K and RT, tunnel current I and dynamic conductance dI/dV as functions of the de bias voltage at 4.2 K, and inelastic electron tunneling (IET) spectroscopy, d(2)I/dV(2) versus V, at 4.2 K for a tunnel junction of Ta(5 nm)/Ni79Fe21(25 nm)/Ir22Mn78(12 nm)/Co75Fe25(4.nm)/Al(0.8 nm)-oxide/Co75Fe25(4.nm)/Ni79Fe21(25 nm)/Ta(5 nm) were systematically investigated. High TMR ratio of 59.2% at 4.2 K and 4..3. at RT were observed for this junction after annealing at 275 degreesC for an hour. The temperature dependence of TMR ratio and resistances from 4.2 to 3.0 K at 1.0 mV bias and the de bias voltage dependence of TMR ratio at 4.2 K from 0 to 80 mV can be evaluated by a comparison of self-consistent calculations with the experimental data based on the magnon-assisted inelastic excitation model and theory. An anisotropic wavelength cutoff energy of spin-wave spectrum in magnetic tunnel junctions (MTJs) was suggested, which is necessary for self-consistent calculations, based on a series of IET spectra observed in the MTJs.

关键词： off TMR A Self-consistent Calculation and an Anisotropic Wavelength Cut energy of Spin-wave Spectrumin Magnetic Tunnel Junctions wave Figure than