检索结果-南通市图书馆

ROCK ASSOCIATIONS AND PETROGENESIS OF INDOSINIAN ALKALINE COMPLEX OF THE NORTH HEBEI PROVINCE, NORTH china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Scientia Geologica Sinica 1999年第1期 65-76页

作者： Zhang Zhaochong (institute of Geology, chinese {2. of Geological Sciences, beijing, 100037)

The Indosinian alkaline complexes in northern Hebei Province are distributed along the two deep faults striking in an approximately east-west direction. These alkaline complexes arc divided into three rock associations: （1） pyroxene diorite-quartz alkaline-feldspar syenite-alkali-feldspar granite-syenite- aegirine-augite syenite-alkali-feldspar granite, （2. pyroxenite-biotite pyroxenite-magnetite apatitic rock -syenite; （3） nepheline syenite-unite-aegirine-augite syenite-ijolite. The former one occurs along the north deep fault, and the latter two along the south deep one. From north to south, the alkaline complexes increase in alkalinity and decrease in the contents of SiO2. Their geochemical characteristics show that the first rock association originated from the transition zone between the crust and the mantle, whereas the latter two originated from the replaced mantle. Their magmas experienced different evolutional processes. These alkaline complexes were resulted from the collision between the Sibrian plate and the Sino-Kerea plate at the end of Hercynian period.

关键词： ROCK ASSOCIATIONS AND PETROGENESIS OF INDOSINIAN ALKALINE COMPLEX OF THE NORTH HEBEI PROVINCE Chen Zhang NORTH china Wang La

A comparison between simulated and measured CO_2.and water flux in a subtropical coniferous forest

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第S2期49卷 241-251页

作者： GU Fengxue, CAO Mingkui, WEN Xuefa, LIU Yunfen & TAO Bo institute of Geographic Sciences and Natural Resources Research, chinese {2. of Sciences, beijing 100101, china Graduate University of the chinese {2. of Sciences, beijing 100049, china 1. institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 2. Graduate University of the chinese academy of Sciences Beijing 100049 China

Using data from eddy covariance measurements in a subtropical coniferous forest, a test and evaluation have been made for the model of Carbon Exchange in the Vegetation-Soil-Atmosphere (CEVSA) that simulates energy transfers and water, carbon and nitrogen cycles based on ecophysiological processes. In the present study, improvement was made in the model in calculating LAI, carbon allocation among plant organs, litter fall, decomposition and evapotranspiration. The simulated seasonal variations in carbon and water vapor flux were consistent with the measurements. The model explained 90% and 86% of the measured variations in evapotranspiration and soil water content. However, the modeled evapotranspiration and soil water content were lower than the measured systematically, because the model assumed that water was lost as runoff if it was beyond the soil saturation water content, but the soil at the flux site with abundant rainfall is often above water saturated. The improved model reproduced 79% and 88% of the measured variations in gross primary production (GPP) and ecosystem respiration (Re), but only 31% of the variations in measured net ecosystem exchange (NEP) despite the fact that the modeled annual NEP was close to the observation. The modeled NEP was generally lower in winter and higher in summer than the observations. The simulated responses of photosynthesis and respiration to water vapor deficit at high temperatures were different from measurements. The results suggested that the improved model underestimated ecosystem photosynthesis and respiration in extremely condition. The present study shows that CEVSA can simulate the seasonal pattern and magnitude of CO2.and water vapor fluxes, but further improvement in simulating photosynthesis and respiration at extreme temperatures and water deficit is required.

关键词： ecosystem CO2 and water flux CEVSA eddy covariance subtropical coniferous forest.

Evidence of the Pan-Lake Stage in the Period of 40-2. ka B.P. on the Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2000年第2期74卷 266-272页

作者： ZHENG Mianping, MENG Yifeng and Wei LejunResearch & Development Center of Saline Lake and Epithermal Deposits,chinese academy of Geological Sciences, {2. 100037 Research & Development Center of Saline Lake and Epithermal Deposits Chinese Academy of Geological Sciences Beijing 100037 [?]2.heng Mianping Born in Fujian in 1934 graduated from the Department of Geology Nanjing University in 1956. He was studied the geology of saline deposits for more than 40 years and made systematic and pioneering studies on saline lakes of the Qinghai-Tibet plateau. Now he is chief of the Research & Development Center of Saline Lakes and Epithermal Deposits Chinese Academy of Geological Sciences and an academician of the Chinese Academy of Engineering as well as a member of the Executive Committee of the International Society of Saline Lakes. E-mail: zmp@***

The Qinghai-Tibet plateau is one of major saline lake regions in china, where saline lakes are widespread and constitute an important object of researches on the palaeoclimatic change in the region. On the basis of comprehensive investigations of the evolution of the lake's surface and sediments on the plateau, the authors have further demonstrated the existence of a pan-lake stage (river and lake flooding stage) on the Qinghai-Tibet plateau during the period of about 40+-2. ka B.P. and analyzed the palaeoclimatic characteristics of the pan-lake period and relationships between the ancient monsoons and the uplift of the plateau since the beginning of the Quaternary.

关键词： Qinghai-Tibet plateau Late Pleistocene pan-lake event palaeoclimate

Test mass charging simulation of ASTROD I due to solar energetic particles at 0.5 AU

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2010年第6期53卷 1139-1143页

作者： BAO Gang & LIU Lei Purple Mountain Observatory,chinese academy of Sciences,Nanjing 2.0008,{2. 1. Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China

Maintaining the geodesic motion of the test mass is vital to ASTROD I space mission. However,the electrostatic charging of the test mass due to cosmic rays and solar energetic particles will result in Coulomb and Lorentz forces and consequently influence the test mass motions. To estimate the size of these effects,a credible simulation of test mass charging processes is critically required. Using the GEANT4 software toolkit,we have modeled the charging processes and predict how the ASTROD I test mass will charge positively at a rate of 2.7370 e + /s,due to solar energetic particles(SEPs) at～0.5 AU caused by the largest SEPs event on 2.,September,1989. In addition to Monte Carlo uncertainty,an error of ±30% in the net charging rates was added to account for uncertainties in the spectra,physics and geometry models.

关键词： charging simulation ASTROD I GEANT4 solar energetic particles

在线全文

学校读者我要写书评

暂无评论

坛紫菜体细胞单克隆叶状体途径及海上养殖

水产学报 2004年第4期28卷 407-412页

作者：刘必谦曾庆国骆其君杨锐王亚军宁波大学海洋生物工程浙江省重点实验室宁波大学海洋生物二程浙江省重点实验室宁波大学海洋生物二程浙江省重点实验室浙江宁波 3152.1 浙江宁波 3152.1 中国科学院海洋研究所山东青岛 2.6071 中国科学院研究生院北京 100039

用海螺酶酶解坛紫菜叶状体制备游离的营养细胞,在显做镜下挑选出单个细胞放入96孔板,在2.℃,1500～2.00 lx,12.:12.条件下进行隔离培养。一部分细胞直接发育形成了叶状体:一种途径是单个细胞通过典型的两级分裂发育成叶状体,也有一些单... 详细信息

用海螺酶酶解坛紫菜叶状体制备游离的营养细胞,在显做镜下挑选出单个细胞放入96孔板,在2.℃,1500～2.00 lx,12.:12.条件下进行隔离培养。一部分细胞直接发育形成了叶状体:一种途径是单个细胞通过典型的两级分裂发育成叶状体,也有一些单细胞先形成叶片状的细胞团,然后在细胞团一端形成假根;另一种途径是部分单细胞先形成“愈伤组织”,经过一段时间培养后放散出类似“孢子”的细胞,其中部分“孢子”发育成叶状体。由单细胞克隆培养获得的叶状体经组织培养形成纯合丝状体,这种纯系丝状体扩大培养后转入传统的育苗途径下海养殖。纯系在苗网附着率、叶片质量和性成熟时间等经济性状方面比未经选育的普通种有优势。

关键词：坛紫菜体细胞叶状体纯系

An emerging draft sequence of the tomato genome-chromosome 3 sequencing in china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

An emerging draft sequence of the tomato genome-chromosome 3...

Genome-wide Association Mapping of Heading Date in Rice

第十一届全国植物基因组学大会

作者： Jianfeng Ren~1,Liuhua Yan~1,Shengxiong Huang~1,Changbao Li~2.Jiuhai Zhao~1,Bao Wang~1,Hongling Jiang~1 and Chuanyou Li~(1*) 1 institute of Genetics and Developmental Biology,chinese {2. of Sciences,beijing 100101,china 2.beijing Vegetable Research Center,beijing {2. of Agriculture and Forestry Sciences,beijing 100097, china

Tomato(Solanum lycopersicum) is considered as a unique model system for studying fruit biology and plant *** a small diploid genome(～950 Mb) and high synteny conservation with other Solanaceae,tomato genome will serv...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Genome-wide Association Mapping of Heading Date in Rice

TAXONOMIC STUDIES ON THE SCIARIDAE (PIPTERA: NEMATOCERA)OF GUIZHOU

第十二届全国植物基因组学大会

作者： Canyang Li~1,Lizhen Si~1,Xuehui Huang~1,Yan Zhao~1,Qi Feng~1,Bin Han~(1,2.) 1.National Center For Gene Research,institute of Plant Physiology and Ecology,Shanghai institutes For Biological Sciences, {2. academy of Sciences,Shanghai 2.02.3,china 2.Cas Key Laboratory of Genome Sciences and Information,beijing institute of Genomics,{2. academy of Sciences,beijing 10002.,china

The adaptation of plants to natural environments depends on the adaptation of flowering-time control at the appropriate season to set *** the genetic basis of flowering-time control is important for agriculture. Here,we performed genome-wide association studies(GWAS) for heading date trait in the population of Oryza sativa indica *** have identified 7 loci which were associated with heading *** order to further verify the possibility of these loci in controlling heading date,we also observed the heading date phenotype of the corresponding chromosome segment substitution lines(CSSLs) deriving from a back-

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Entomotaxonomia 1993年第4期 312-318页

作者： YANG Chi-kun, ZHANG Xuemin and YANG ChunqingDepartment of Plant Protection, beijing Agricultural U niversity, beijing 100094{2. academy of Agricultural Sciences, beijing 100094{2. academy of Medical Sciences, beijing 100094

The family Sciaridae of Guizhou Province contains 10 genera and 57 species, ofwhich 1 genus and 43 species are new to science. The new taxa are described in taxonomickeys. The type specimens are kept in the Insect Collection of beijing Agricultural Univer-sity. The letters given here are locality abbreviations used in the genus and specics listthat follows.

关键词： Diptera Sciaridae New species Guizhou.

医学领域的磁共振成像革命——2.03年诺贝尔生理及医学奖主要工作介绍

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

生物化学与生物物理进展 2003年第6期30卷 827-832页

作者：王波钟凯中国科学院研究生院中国科学院生物物理研究所认知科学重点实验室北京100101

在磁场中 ,自旋的原子核会吸收频率与其自旋频率相同的电磁波 ,使自身能量增加 ,发生能级跃迁 ,当原子核迁移回原能级时 ,就会把多余的能量以电磁波的形式释放出来 ,称为核磁共振 (NMR) .磁共振成像(MRI)利用这一原理 ,依据所释放的能... 详细信息

在磁场中 ,自旋的原子核会吸收频率与其自旋频率相同的电磁波 ,使自身能量增加 ,发生能级跃迁 ,当原子核迁移回原能级时 ,就会把多余的能量以电磁波的形式释放出来 ,称为核磁共振 (NMR) .磁共振成像(MRI)利用这一原理 ,依据所释放的能量在物质内部不同结构环境中不同的衰减 ,通过外加梯度磁场检测所发射出的电磁波 ,即可得知构成这一物体原子核的位置和种类 ,据此可以绘制成物体内部的结构图像 .将这种技术用于人体内部结构的成像 ,就产生出一种革命性的医学诊断工具 .快速变化的梯度磁场的应用 ,大大加快了磁共振成像的速度 ,使该技术在临床诊断、科学研究的应用成为现实 ,极大地推动了医学。

关键词：磁共振成像核磁共振梯度磁场平面回波扫描医学诊断