检索结果-南通市图书馆

Effects of various solar indices on accuracy of Earth’s thermospheric neutral density models

science China(Physics,Mechanics & Astronomy) 2009年第7期52卷 1120-1128页

作者： WANG HongBo1,2 & ZHAO ChangYin1 1 Purple Mountain Observatory, chinese academy of sciences, Nanjing 210008, China 2 graduate {3. of chinese academy of sciences, beijing 100049, China Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China graduate university of chinese {3. of sciences Beijing 100049 China

Four kinds of solar indices F10.7, E10.7, s10, Mg10 and four thermospheric neutral density models, i.e., CIRA72, DTM94, NRLMsIsE00 and JB2006, are discussed. The CHAMP accelerometer data are used to calculate thermospheric total mass density. Based on the comparison of the model densities with CHAMP observations, the effects of various indices on the model accuracy are detected. It is found that under quiet and moderate solar conditions (F10.7s’ errors are reduced about 15% by using E10.7 instead of F10.7, while under active solar conditions (F10.7>200) the error’s standard deviation using E10.7 increases quickly and causes the models’ accuracy to fall down. With regard to s10, Mg10, their effects under quiet solar conditions are inconspicuous. If under active solar conditions, they can reduce the model error’s standard deviation by 5%-10%, implying that s10, Mg10 make the model error more stable. The JB2006 model, which was constructed by multi-solar-index (F10.7, s10, Mg10), is compared with DTM94 and NRLMsIsE00 based on single-solar-index. It is found that JB2006’s accuracy is better than DTM94’s, and is close to NRLMsIsE00 under the quiet solar condition. During the solar burst occurring on October 26, 2003. JB2006 has been in best agreement with CHAMP observations. All in all, the new indices may improve thermospheric density models’ accuracy under some special conditions. Concretely, E10.7 may reduce the average error of models and s10, Mg10 may prevent the error’s divergence.

关键词： solar radiation index CHAMP accelerometer data neutrals density model

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

Quasi-secure quantum dialogue using single photons

引用

science China(Physics,Mechanics & Astronomy) 2007年第5期50卷 558-562页

作者： YANG YuGuang1,2 & WEN QiaoYan3. College of Computer science and Technology, beijing university of Technology, beijing 100022, China {3.tate Key Laboratory of Information security, {3. university of the chinese academy of sciences, beijing 100049, China 3.school of science, beijing university of Posts and Telecommunications, beijing 100876, China College of Computer science Technology Beijing University of Technology Beijing 100022 China state Key Laboratory of Information security Graduate University of the Chinese Academy of Sciences Beijing 100049 China school of science Beijing University of Posts Telecommunications Beijing 100876 China

A quasi-secure quantum dialogue protocol using single photons was proposed. Different from the previous entanglement-based protocols, the present protocol uses batches of single photons which run back and forth between the two parties. A round run for each photon makes the two parties each obtain a classical bit of information. so the efficiency of information transmission can be increased. The present scheme is practical and well within the present-day technology.

关键词： quantum dialogue, single photon, quantum secure direct communication

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

Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough

引用

中国科学：地球科学英文版 2006年第4期49卷 375-383页

作者： HUANG Peng1,2, LI Anchun1, HU Ningjing2,3. FU Yongtao1& MA Zhibang4 1. Institute of Oceanology, chinese academy of sciences, Qingdao 266071, China 2. graduate school of the chinese academy of sciences, beijing 10003., China 3. Institute of soil science, chinese academy of sciences, Nanjing 210008, China 4. Institute of Geology and Geophysics, chinese academy of sciences, beijing 100029, China 1. Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China 2. graduate school of the chinese academy of sciences Beijing 100039 China 3. Institute of soil science Chinese Academy of Sciences Nanjing 210008 China 4. Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Volcanic rocks from the northern and middle Okinawa Trough were dated by ura- nium-series dating method. Differential fractions using magnetic procedure were designed to separate samples. New report on the ages and isotopic data of rocks in the northern trough (especially black pumice) was discussed. Based on the uranium dates and sr-Nd isotopic ratio, magmatic evolution process of the Okinawa Trough was noted. Firstly, there have been wide silicic volcanic activities in the Okinawa Trough from late Pleistocene to present, and the volcanic rocks can be divided into three subgroups. secondly, magma generally came from PREMA source area under the Okinawa Trough. Magmatic evolution in the northern trough was similar to the middle, but different to the south. Finally, volcanic activities indicated that opening of the southern Okinawa Trough did not happen due to the collision between Luson Arc and Eurasian Plate until the early Pleistocene.

关键词： Okinawa Trough, black pumice, uranium-series dating, sr-Nd isotopic ratio, magmatic evolution.

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

Construction of AFLP-based genetic linkage maps for the chinese shrimp Fenneropaeneus chinensis

引用

chinese science Bulletin 2008年第8期53卷 1205-1216页

作者： TIAN Yi1,2,3.4, KONG Jie1↑ & WANG WeiJi1 1 Yellow sea Fisheries Research Institute, chinese academy of Fishery science, Qingdao 266071, China 2 College of Life science and Technology, Dalian Fisheries university, Dalian 116023. China 3.Institute of Oceanology, chinese academy of sciences, Qingdao 266071, China 4 graduate university of chinese academy of sciences, beijing 100049, China chinese Acad Fisheries sci Yellow Sea Fisheries Res Inst Qingdao 266071 Peoples R China.

Fenneropaeneus chinensis is an important species in marine fishery resources and aquaculture in China. A genetic linkage map is essential for improving the efficiency of its breeding by marker-as- sisted selection and identifying commercially important genes. Linkage maps of F. chinensis were constructed with an F2 mapping population (110 progenies) using amplified fragment length polymor- phic (AFLP) marker in this study. Fifty-five AFLP primer combinations produced 53. AFLP markers fitting for map strategy in mapping family. The markers with 3.1 segregating ratios were analyzed using F2 intercross model for the common linkage map, while the markers with 1:1 ratio were analyzed using the pseudo-testcross strategy. The maps of male, female and common were constructed. The female map included 103.markers that formed 28 linkage groups, covering a total length of 1090 cM. All mark- ers were linked with the linkage groups. segregation distortion was observed for 6 of 103.markers in the female map. The average distance between markers was 14.53.cM and ranged from 4.4 to 24.8 cM. The male map included 144 markers that formed 3. linkage groups. Ten markers remained unlinked in male map. segregation distortion was observed for 7 of 144 markers in the male map. The total dis- tance of male map covered 1617 cM. The average distance between markers was 16.3. cM. The male map was 3..6% longer than the female map, which may reflect sex-specific recombination rates in chinese shrimp. The common map was composed of 216 markers, including in 44 linkage groups covering a total distance of 1772.1 cM. Two markers remained unlinked. No distorted markers of 216 markers were shown in the common map. The distance between markers was 10.42 cM. An average estimated genome size for the chinese shrimp was 2420 cM, which was consistent with the relative size of the Penaeid genome. The distribution of AFLP markers was relatively even in chromosomes of Chi- nese shrimp maps. The linkage analysis

关键词： AFLP 海洋渔业虾中国

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

structure of augmentation quotients of finite homocyclic abelian groups

引用

science China Mathematics 2007年第9期50卷 1280-1288页

作者： Guo-ping TANG school of Mathematical sciences,graduate university of chinese {3. of sciences,beijing 100049,China 1. school of Mathematical sciences Graduate University of Chinese Academy of Sciences Beijing 100049 China

Let G be a finite abelian group and its sylow p-subgroup a direct product of copies of a cyclic group of order p r , i.e., a finite homocyclic abelian group. Let Δ n (G) denote the n-th power of the augmentation ideal Δ(G) of the integral group ring ?G. The paper gives an explicit structure of the consecutive quotient group Q n (G) = Δ n (G)/Δ n+1(G) for any natural number n and as a consequence settles a problem of Karpilovsky for this particular class of finite abelian groups.

关键词： integral group ring augmentation ideal consecutive quotient of augmentation ideal 16s3. 20C05

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

Electronic structure and magnetism of Fe-doped siC nanotubes

引用

science China(Physics,Mechanics & Astronomy) 2010年第9期53卷 1582-1589页

作者： ZHANG WeiHu1,2,3.ZHANG FuChun3.ZHANG ZhiYong4,LU shuYuan5 & YANG YanNing3.1 Xi’an Institute of Optics and Precision Mechanics,chinese academy of sciences,Xi’an 710068,China 2 graduate {3. of chinese academy of sciences,beijing 100049,China 3.College of Physics and Electronic Information,Yan’an {3.,Yan’an 716000,China 4 Information science and Technology Institution,Northwest {3.,Xi’an 710127,China 5 Department of Telecommunications,Xi’an Institute of Posts and Telecommunications,Xi’an 710121,China 1. Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an 710068 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. College of Physics and Electronic Information Yan’an University Yan’an 716000 China4. Information Science and Technology Institution Northwest University Xi’an 710127 China5. Department of Telecommunications Xi’an Institute of Posts and Telecommunications Xi’an 710121 China

The electronic structure and magnetic properties of Fe-doped siC nanotubes are investigated by using the first-principles method based on density functional theory(DFT) in the local spin density approximation(LsDA).The calculation results indicate that the siC nanotube of Fe substitution for C exhibits antiferromagnetism while ferromagnetism features prominently when Fe substitutes *** is a kind of half-metal magnetic *** formation energy calculation results show that the formation energy of ferromagnetic structure is 3.2 eV lower than that of antiferromagnetic *** atoms are more likely to replace si ***-orbit coupling induces electron spin polarization in the ground ***,the doping Fe atoms make relaxation towards the outside of the tube to some extent and larger geometric distortion occurs when Fe substitutes C,but the whole geometric structure of siC nanotubes is not damaged due to the *** is revealed in the calculation of energy band structure and density of states that more dispersed distribution of energy levels is produced near the Fermi *** Fe substitution for si,obviously there are spin-split and intense p-d hybrid effects by si 3. electron spins and Fe 3. electron spins localized at the exchanging interactions between magnetic transitional metal(TM) *** electronic density results indicate that system magnetic moments are mainly generated by the unpaired 3. electrons of Fe *** these results show that the transition metal doping siC nanotube could be a potential route to fabricating the promising magnetic materials.

关键词： siC nanotube the first-principles doped magnetic properties

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 new method to prepare clean cuticular membrane from fossil leaves with thin and fragile cuticles

引用

science China Earth sciences 2011年第2期54卷 223-227页

作者： WANG Li1,2 & LENG Qin1,3.1 state Key Laboratory of Palaeobiology and stratigraphy,Nanjing Institute of Geology and Palaeontology,chinese academy of sciences,Nanjing 210008,China 2 graduate school of chinese academy of sciences,beijing 100049,China 3.Department of science and Technology,Bryant university,smithfield RI 02917,UsA 1. state Key Laboratory of Palaeobiology and stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China2. Graduate School of Chinese Academy of Sciences Beijing 100049 China3. Department of Science and Technology Bryant University Smithfield RI 02917 USA

Leaf cuticle analysis has long been a powerful tool for fossil plant identification, systematics, and palaeoclimatological recon- struction. In recent decades the application of stomatal frequency data that are relied on precise calculation of stomata on plant fossil cuticles to reconstruct ancient atmospheric CO2 concentration made the preparation of cuticular membrane with sufficient size a critical technique in palaeoclimatological research. However, for plants with originally thin and fragile cuticles, e.g., most deciduous plants, conventional techniques sometimes fail to obtain cuticular membranes with sufficient size, or sometimes unable to recover any. This has largely hampered the usage of fossil cuticle analysis in palaeobotanical and palaeo- climatological research. Here, we describe a new method using clear nail polish as a medium to ＂strengthen＂ the originally thin and fragile cuticles prior to maceration procedures. We demonstrate the method by using middle Eocene Metasequoia fossils that were notorious for the difficulty of recovering large-sized clean cuticular membranes due to their thin and fragile nature. Metasequoia, with well-documented and widely-distributed fossil records since the Late Cretaceous and with a living repre- sentative, 114. glyptostroboides, as a comparative reference, bas been widely used as a model genus for the study of evolution of plants, palaeoclimatological reconstruction, and plant adaptation to climate changes. But its deciduous habit produces thin cuticles and makes the preparation of clean cuticular membranes a tedious process. The new method successfully allows us to recover its delicate cuticular membranes with sufficient sizes for sEM observation and stomatal frequency analysis.

关键词： fossil leaf cuticle Metasequoia new method thin and fragile cuticle sEM observation stomatal frequency CO2

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

Orbit determination and prediction accuracy analysis for a regional tracking network

引用

science China(Physics,Mechanics & Astronomy) 2010年第6期53卷 1130-1138页

作者： ZHOU shanshi 1,2,3.,HU XiaoGong 1 & WU Bin 1 1 shanghai Astronomical Observatory,chinese academy of sciences,shanghai 20003.,China 2 graduate {3. of chinese academy of sciences,beijing 100049,China 3.Research Center of GNss,Wuhan 43.079,China 1. shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Research Center of GNSS Wuhan 430079 China

China's COMPAss satellite navigation system relies on a regional tracking network to provide navigation services. Limited by its geographic border,the regional network is able to cover only 3.% of the medium-earth-orbits(MEO). Accuracy of determined and predicted orbits is not able to satisfy system requirements if the tracking data processing strategy for global tracking network processing is used for the regional network. Two major error sources for orbital prediction are accuracy of initial orbital elements and dynamical modeling. To achieve better prediction accuracy,we propose a two-step orbit determination and prediction strategy. For step 1,only solar radiation pressure(sRP) parameters are estimated along with the orbital elements and other parameters; for step 2,all parameters are estimated but the sRP parameters are tightly constrained to their step 1 estimates. Experimenting with data from a regional GPs network,we conclude for orbital prediction using the proposed two-step strategy,the average user range error(URE) for 24-h prediction arcs is better than 0.6 m.

关键词： orbit determination and prediction regional tracking network URE

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

Changes of decay rates of radioactive ^(111)In and ^(3.)P induced by mechanic motion

引用

science China Chemistry 2007年第2期50卷 170-174页

作者： HE YuJian1,QI Fei2 & QI shengChu3.1 College of Chemistry and Chemical Engineering,graduate university of chinese {3. of sciences,beijing 100049,China 2 No. 1,Gravenhurst Court,Gaithersburg,Md 20878,UsA 3.Department of Applied Chemistry,Peking university,beijing 100871,China 1. College of Chemistry and Chemical Engineering Graduate University of Chinese Academy of Sciences Beijing 100049 China 2. No. 1 Gravenhurst Court Gaithersburg Md 20878 USA 3. Department of Applied Chemistry Peking University Beijing 100871 China

The changes of decay rates of radionuclide 111In(electron capture) and 3.P(β decay) induced by exter-nal mechanic motion are studied. The results indicate that,in the external circular rotation in clockwise and anticlockwise centrifuge on Northern Hemisphere(radius 8 cm,2000 r/min) ,the half life of 111In compared with the referred(2.83.d) is decreased at 2.83. and increased at 1.77%,respectively;the half life of 3.P compared with the referred(14.29 d) is decreased at 3.78% and increased at 1.75%,respec-tively. When the clockwise and anticlockwise rotations increase to 4000 r/min,the half life of 111In is decreased at 11.3.% and increased at 6.3.%,respectively;the half life of 3.P is decreased at 10.08% and increased at 4.3.%,respectively. When the circular rotation is removed,the decay rates of 111In and 3.P return back to the referred,respectively. It is found that the external circular rotations in clockwise and anticlockwise centrifuge selectively increased and decreased the decay rates of 111In and 3.P,respec-tively,and the effects are strongly dependent on the strength of circular rotation. It is suggested that these effects may be caused by the chiral interaction.

关键词： circular rotation helical motion 111In 3.P decay rate chirality

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

The influence of moderate ENsO on summer rainfall in eastern China and its comparison with strong ENsO

引用

chinese science Bulletin 2008年第5期53卷 791-800页

作者： XUE Feng1 & LIU ChangZheng1,2 1 Institute of Atmospheric Physics, chinese academy of sciences, beijing 100029, China 2 {3. university of chinese academy of sciences, beijing 100049, China chinese Acad sci Inst Atmospher Phys Beijing 100029 Peoples R China.

The 6 major ENsO events since 1979 are classified into the strong and moderate ENsO based on in-tensity. The composite analysis is performed to reveal the influence of ENsO on East Asian summer monsoon (EAsM) and summer rainfall in eastern China. It is shown that the influence is changed with the seasonal cycle in summer, with a weaker influence in June and a stronger influence in August, in-dicating a long lagged effect of ENsO on EAsM. Besides, the circulation and rainfall anomalies caused by the strong ENsO are also stronger with an earlier starting time, while the influence of the moderate ENsO is evident in August. The composite summer rainfall in eastern China for the moderate ENsO exhibits a northern rainfall pattern, which is totally different from the classical ENsO-type rainfall pat-tern. Based on the composite analysis, two moderate ENsO years with a similar intensity (i.e., 1995 and 2003. are compared. The result shows that, the response of EAsM to the moderate ENsO during June and July is, to a certain degree, modulated by the circulation systems in mid-high latitudes of Eurasia and in the southern Hemisphere, thereby inducing a different rainfall distribution in eastern China. In comparison with the strong ENsO in 1983. it is further revealed that, the strong ENsO plays a dominant role in summer rainfall anomalies in eastern China as well as in controlling the influence of the other factors on EAsM. The strong ENsO is therefore different with the moderate ENsO.

关键词：中国东部海洋气象学厄尔尼诺现象东亚季风降雨

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：