检索结果-南通市图书馆

prediction method for October 2.03 solar storm

Science china(Technological Sciences) 2006年第5期49卷 629-640页

作者： XIE Yanqiong1, 2. 3, WEI Fengsi1, FENG Xueshang1 & ZHONG Dingkun1, 2.1. State Key Laboratory of Space Weather, center for Space Science and Applied Research, Chinese Academy of Sciences, beijing 100080,{2. 2. Graduate School, Chinese Academy of Sciences, beijing 100039,{2. 3. Institute of Meteorology, PLA University of Science and Technology, Nanjing 2.1101,{2. State Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Graduate School Chinese Academy of Sciences Beijing China Institute of Meteorology PLA University of Science and Technology Nanjing China

Aiming at two intense shock events on October 2. and 2., 2.03, this paper presents a two-step method, which combines synoptic analysis of space weather ——“observing” and quantitative prediction ——“palpating”, and then uses it to test predictions. In the first step of “observing”, on the basis of observations of the solar source surface magnetic field, interplanetary scintillation (IPS) and ACE spacecraft, we find that the propagation of the shocks is asymmetric relative to the normal direction of their solar sources, and the Earth is located near the direction of the fastest speed and the greatest energy of the shocks. As the two fast ejection shock events, the fast explosion of coronal mass of the extremely high temperature, the strong magnetic field, and the high speed background solar wind are also helpful to their rapid propagation. In the second step of “palpating”, we adopt a new membership function of the fast shock events for the ISF method. The predicted results show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8% and 6.7%; and for the magnetic disturbance magnitude, the relative errors are 4.1% and 3.1%, re- spectively. Furthermore, the comparison among the predicted results of our two-step method with those of five other prevailing methods shows that the two-step method is advantageous. The results tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction precision.

关键词： solar storm, interplanetary shock, interplanetary scintillation, two-step method, ISF method.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Application of cathodoluminescence to zircon in FEG-ESEM

引用

Progress in Natural Science:Materials International 2006年第9期16卷 919-924页

作者： CHEN Li , XU Jun and SU Li (Electron Microscopy Laboratory, School of Physics, Peking University, beijing 100871, china Geology Experimental {2., china University of Geoscience, beijing 100083, china) Electron Microscopy Laboratory School of Physics Peking University Beijing 100871 China Geology Experimental center China University of Geoscience Beijing 100083 China

Cathodoluminescence (CL) image analysis of zircon is a key step of mineral micro-area compositional investigation and U-(Th)-Pb dating. We introduce a system consisting of field emission ESEM and high performance cathodoluminescence. This system has obvious advantages in imaging resolution and CL spectrum. We acquired some zircon CL images and spectra to demonstrate the ability of this system. Our results show that this system has a great potential application to characterize and identify the genesis of zircon.

关键词： zircon cathodoluminescence ESEM.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The mechanism of breakdown in laminar-turbulent transition of a supersonic boundary layer on a flat plate-temporal mode

引用

Science china(Physics,Mechanics & Astronomy) 2005年第5期48卷 614-625页

作者： HUANG Zhangfeng 1, CAO Wei 1,2.& ZHOU Heng 1,2.1. Department of Mechanics, Tianjin University, Tianjin 300072. china 2. Liu-Hui center of Applied Mathematics, Nankai University and Tianjin University, Tianjin 300072. china Department of Mechanics Tianjin University Tianjin China Liu-Hui center of Applied Mathematics Nankai University and Tianjin University Tianjin China

Temporal mode direction numerical simulation has been done for the transition of a supersonic boundary layer on a flat plate with Mach number 4.5. analysis of the result showed that during the breakdown process in laminar-turbulent transition, the mechanism causing the mean flow profile to evolve swiftly from laminar to turbulent was that the modification of mean flow profile by the disturbances,when they became larger,led to a remarkable change of its stability characteristics. Though the most unstable T-S wave was of second mode for laminar flow, the first mode waves played the key role in the breakdown process in laminar-turbulent transition.

关键词： supersonic boundary layer, transition, breakdown.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

analysis on Depth Distribution and Precursor Mechanism of Small and Moderate Earthquakes

引用

Earthquake Research in china 2001年第4期15卷 406-411页

作者： Wang JianInstitute of Geophysics, china seismological bureau, beijing 100081,{2. Institute of Geophysics China Seismological Bureau Beijing 100081 China

In this paper, the focus depth distribution of earthquakes with each magnitude has been analyzed. Statistic data show that the lower magnitude is, the wider focus depth distributes. With larger magnitude, the focus tends to be concentrated in upper or middle crustal layers. We analyzed the cause of focus depth distribution and explained the precursor mechanism of small and moderate earthquakes with occurring condition and characteristics of strong earthquakes. The results of this paper may be applied to determine risk sites of strong earthquakes.

关键词： Seismicity Depth distribution Precursor Long- and medium-term earthquake prediction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigating spatial distribution of tourist attractions’inlinks: A case study of three mountains

引用

Science china(Technological Sciences) 2010年第S1期53卷 126-133页

作者： ZHANG Yi 1,QI LiNa 2.YANG AnRan 1,SHI Lei 1 & XU Li 1 1 Institute of RS and GIS,Peking University,beijing 100871,china 2.{2. for Recreation and Tourism Research,Peking University,beijing 100871,china Institute of RS and GIS Peking University Beijing China center for Recreation and Tourism Research Peking University Beijing China

In hyperlink analysis,most researchers focus on interpreting hyperlink counts,they seldom concern themselves enough about the significance of spatial distribution of *** this paper,we argue that not only can the inlink count to a tourist attraction’s official website reflect its attractiveness,but also the spatial distribution of its inlinks can reflect the distribution of its tourist source *** mountains in Anhui Province,china,are chosen for the case ***,the correlation between the spatial distributions of an attraction’s tourist source markets and its official website’s inlinks is ***,the tourism indexes such as the spatial concentration index(SCI)and the attraction radius(AR),which are calculated by inlinks,are compared to the real indexes based on tourist ***,the detailed discussion and analysis are presented and an improved model,which is used to calculate the distribution of inlinks,is proposed.

关键词： tourist attractiveness hyperlink analysis spatial distribution of hyperlinks tourist source market

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Some evidence of drying trend over northern china from 1951 to 2.04

引用

Chinese Science Bulletin 2006年第23期51卷 2913-2925页

作者： MA Zhuguo1,2.& FU Congbin1,2.1. Key Laboratory of Regional Climate-Environment for Temperate East Asia, Chinese Academy of Sciences, beijing 10002., china 2. START Regional {2. for Temperate East Asia, Institute of Atmos-pheric Physics, Chinese Academy of Sciences, beijing 10002., china Key Laboratory of Regional Climate-Environment for Temperate East Asia Chinese Academy of Sciences Beijing China START Regional center for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The surface wetness index, Palmer drought sererity index and the retrieval of soil moisture over china were calculated using monthly precipitation and monthly mean surface air temperature. Based on the contrast analysis of the variation of the above three indices and precipitation, the dry/wet spatio-temporal pattern of northern china in the last 54 years was revealed, and the evidence of drying trend over northern china was analyzed, especially. The results show the following four facts: (1) The drying trend is the main characteristic of the eastern part of Northwest china and the central part of North china since the 1980s and it was enhanced in the last 15 years mainly due to the precipitation decrease and the temperature increase; (2. During the last 54 years, there was only one dry/wet shift at the interdecadal scale occurring in the eastern part of Northwest china and the central part of North china in the late 1970s, which was related to 1977/1978 global abrupt change, whereas there were three shifts in Northeast china, one was in the mid 1990s and the other two were in 1965 and 1983, respectively; (3) Unlike the variation trend of other subregions of northern china, the western part of Northwest china is currently located in a relatively wetting period, which is weak-ened due to the temperature increase; (4) The extreme drought frequency is obviously increasing in the eastern part of Northwest china, the central part of North china and Northeast china since the 1980s, which is closely related to the precipitation decrease and temperature increase in these subregions.

关键词：中国北方干燥趋向干旱索引气候背景

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Semi-analytical analysis of the response of the air temperature over the land surface to the global vegetation distribution

引用

Chinese Science Bulletin 2009年第14期54卷 2499-2505页

作者： LIU Fei1,2.& CHAO JiPing3,4 1 Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., china 2.Graduate University of Chinese Academy of Sciences, beijing 100049, china 3 National Marine Environmental Forecasting center, beijing 100081, china 4 First Institute of Oceanography, State Oceanic Administration of china, Qingdao 2.6061, china Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China National Marine Environmental Forecasting center Beijing China First Institute of Oceanography State Oceanic Administration of China Qingdao China

Response of the air temperature over the land surface to the global vegetation distribution is investigated, using a three-dimensional governing equation to simulate the steady, large-scale, limited amplitude perturbation of the free, inviscid and adiabatic atmosphere. The adoption of the static equation leads to a temperature governing equation in the terrain following coordinate. With the prescribed temperature as the upper boundary condition and the radiation balance as the lower boundary condition, the semi-analytical solution of the global circulation temperature can be calculated. In this article, only the air temperature (at 2.m height) over the land surface is analyzed, and the result suggests that this model can simulate the air temperature pattern over the land surface reasonably. A better simulation occurs when a simple feedback of the albedo on the temperature is included. Two sensitivity experiments are analyzed through this model. One suggests that the air temperature over the land surface descends obviously when the land surface is covered with ice all over, while another suggests that the air temperature rises a little when the land surface is covered with forest except the ice-covered area. This model appears to be a good tool to study the response of the air temperature to the vegetation distribution. Limitations of the model are also discussed.

关键词：空气温度植被分布陆地表面反应解析分析模拟模式控制方程边界条件

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Heterotrimeric G protein α subunit is involved in rice brassinosteroid response

引用

Cell Research 2006年第12期16卷 916-922页

作者： Lei Wang~(1,2. Yun-Yuan Xu~1 Qi-Bin Ma~(1,2. Dan Li~(1,2. Zhi-Hong Xu~(1,3) Kang Chong~(1,3) 1 Key Laboratory of Photosynthesis and Environmental Molecular Physiology,Institute of Botany,Chinese Academy of Sciences,Nanxincun 2.,Xiangshan,beijing 100093,china,2.Graduate School of the Chinese Academv of Sciences,100046 beijing,china 3 National Plant Gene Research center (beijing),beijing 100093,china Key Laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany Chinese Academy of Sciences Xiangshan China Graduate School of the Chinese Academy of Sciences Beijing China National Plant Gene Research center (beijing) Beijing China

Heterotrimeric G proteins are known to function as messengers in numerous signal transduction *** nullmutation of RGA(rice heterotrimeric G protein α subunit),which encodes the α subunit of heterotrimeric G proteinin rice,causes severe dwarfism and reduced responsiveness to gibberellic acid in ***,less is known aboutheterotrimeric G protein in brassinosteroid(BR)signaling,one of the well-understood phytohormone *** thepresent study,we used root elongation inhibition assay,lamina inclination assay and coleoptile elongation analysis todemonstrated reduced sensitivity of dl mutant plants(caused by the null mutation of RGA)to 2.-epibrassinolide(2.-epiBL),which belongs to brassinosteroids and plays a wide variety of roles in plant growth and ***,RGA transcript level was decreased in 2.-epiBL-treated seedlings in a dose-dependent *** results show thatRGA is involved in rice brassinosteroid response,which may be beneficial to elucidate the molecular mechanisms of Gprotein signaling and provide a novel perspective to understand BR signaling in higher plants.

关键词： heterotrimeric G protein α subunit dl mutant BR signaling rice

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The relationship between the canonical ENSO and the phase transition of the Antarctic oscillation at the quasi-quadrennial timescale

引用

Acta Oceanologica Sinica 2010年第6期29卷 26-34页

作者： LIU Changzheng XUE Feng National Climate center Beijing 100081 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

A correlation analysis is performed to investigate the relationship between El Nino-Southern Oscillation （ENSO） and the Antarctic oscillation （AAO） at the quasi-quadrennial （QQ） *** is found that the cold tongue index （CTI） and the AAO index （AAOI） are negatively correlated with about a 7-month lead-time,while they are positively correlated with about a 15-month *** further explore this relationship,complex empirical orthogonal function analysis is employed in the QQ sea level pressure （SLP） anomalies from 1951 to *** results indicate that,during the ENSO cycle,there exists one kind of global tropical wave of wavenumber 1 （GTW1） propagating *** the traveling of GTW1,the tropical SLP anomaly tends to intrude into the southern ***,three strong signals travel synchronously along the circumSouth-Pacific path,and a relatively weak signal extends eastward and poleward over the South Ocean in the Atlantic-Indian Ocean *** the propagation of these signals,the AAO phase tends to be reversed *** a result,there exists an evident lead-lag correlation between CTI and *** can be concluded that ENSO plays a key role in the phase transition of AAO at the QQ *** is also noticed that this regular relationship is only evident in the canonical ENSO events,for which sea surface temperature （SST） anomalies extend westward from the tropical eastern *** the other hand,the similar relationships are not found among those atypical ENSO events for which SST anomalies spread eastward from the central Pacific,such as the 1982.1983 ENSO event.

关键词： ENSO Antarctic oscillation the quasi-quadrennial timescale the global tropical wave of wavenumber 1

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A comparative analysis on two solar proton events

引用

Chinese Science Bulletin 2007年第1期52卷 47-51页

作者： LE GuiMing1,2.3,4, HAN YanBen2.& ZHANG YiJun3 1 Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, china Meteorological Administration, beijing 100081, china 2.National Astronomical Observatories, Chinese Academy of Sciences, beijing 100012. china 3 Chinese Academy of Meteorological Sciences, china Meteorological Administration, beijing 100081, china 4 National center for Space Weather, china Meteorological Administration, beijing 100081, china Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites China Meteorological Administration Beijing China National Astronomical Observatoires Chinese Academy of Sciences Beijing China Chinese Academy of Meteorological Sciences China Meteorological Administration Beijing China

This paper presents a comparative analysis on the two Solar Proton Events (SPE), which occurred on 14 July 2.00 (Bastille Day) and 2. October 2.03 (2.OCT03) respectively. It is found that although the peak flux of the latter seemed to be greater than that of the former based on geostationary observations, the maximum intensities of the energetic protons (>10 MeV and 30 MeV) during the Bastille Day event were all higher than those of the 2.OCT03 event according to the interplanetary observations. Further analysis indicated that the quantity of the seed particles, which could be accelerated to the energies exceeding 10 and 30 MeV by the Coronal Mass Ejection (CME)-driven shock on 14 July 2.00, was far larger than that of the 2.OCT03 event. In the Bastille Day case, when the CME approached to the height around 14 R⊙, the CME-driven shock would reach its maximum capacity in accelerating the solar en- ergetic protons (>100 MeV). In contrast, on 2. October 2.03, when CME approached to the height about 58R⊙, the CME-driven shock reached its highest potential in accelerating the solar energetic protons of the same category. At this moment, the peak flux (>100 MeV) was about 155 pfu, which was much lower than 355 pfu measured on 14 July 2.00. This demonstrated that in the Bastille Day event, the quantity of the seed particles, which could be accelerated to the energy beyond 100 MeV, was significantly larger than its counterpart in the 2.OCT03 case. Therefore, the peak flux of an SPE event depends not only on the interplanetary intensity of the solar energetic particles, but also on the velocity of the associated CME-driven shock, and the quantity of the seed particles as well as on the interplanetary magnetic en- vironment. This paper also reveals that the magnetic sheath associated with ICME on 2. October 2.03 captured a large number of solar energetic protons, including those having energy greater than 100 MeV.

关键词：太阳质子 CME 太阳耀斑太阳系

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：