检索结果-南通市图书馆

Geochemistry of high-Mg andesites from the early Cretaceous Yixian Formation, western Liaoning: Implications for lower crustal delamination and Sr/Y variations

引用

Science china Earth sciences 2006年第9期49卷 904-914页

作者： WANG Xiaorui1, GAO Shan1,2. LIU Xiaoming1, YUAN Honglin1, HU Zhaochu1, ZHANG Hong1,3.& WANG Xuance4 1. State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi`an 710069, china 2. State Key Laboratory of Geological Processes and Mineral Resources, china University of Geo{2., Wuhan 43.074, china 3. Shenyang institute of Geology and Mineral Resources, Shenyang 11003.0} china 4. guangzhou institute of Geochemistry, chinese academy of sciences, guangzhou 510640, china 1. State Key Laboratory of Continental Dynamics Department of Geology Northwest University Xi’an 710069 China 2. State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan 430074 China 3. Shenyang institute of Geology and Mineral Resources Shenyang 110032 China 4. guangzhou institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

85 volcanic rocks of the Yixian Formation from the Sihetun type section werecollected and analyzed for geochemical and isotopic compositions. Major element compositionsindicate that the Sihetun volcanic rocks are high magnesium andesites with some basalts occurring atthe bottom of section. The Sihetun high magnesium andesites (SiO_2.= 52.82.59.3. wt%, Al_2._3.14.15-16.3.wt%) show many characteristics of adakites such as depletion in heavy rare-earth elements(HREE; Yb = 1.03.1.88 μg/g) and Y(12.2. μg/g) and high Sr (62.-13.0} μg/g) and Sr/Y(3.0}88), withhigh La_N/Yb_N ratio (10-2.). They share similar major and trace element characteristics to volcanicrocks from the Xinglonggou Formation except their lower Nd isotope ratios (^(143.Nd/^(144)Nd(13.Ma) = 0.5118-0.5119, ε_(Nd) (13.Ma) = -11.6-13.8, ^(87)Sr/^(86)Sr (13. Ma) = *** were interpreted in a way that eclogite that formed at the base of thickened Archean lowercrust of the North china craton foundered into the convecting mantle and subsequently melted andinteracted with peridotite. However, compared to the Xinglonggou volcanic rocks, the source of theSihetun magma contained more ancient continental crustal material in order to explain its evolved Ndisotopes. The age of the Sihetun Formation was 12. to 13. Ma, and this indicates that delaminationlasted to the early Cretaceous period. The Sr contents and Sr/Y ratios of the Sihetun high-Mgandesites show significant negative correlations with SiO_2.for samples with SiO_2.> 56%. Thesesuggest that the Sr and Sr/Y values were reduced due to fractional crystallization of ***, the effect of crystallization on volcanic Sr and Sr/Y ratio has to be taken intoaccount.

关键词： High-Mg andesite, Adakite, Yixian Formation, North china Craton, delamination.

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

Alterations in DNA methylation and genome structure in two rice mutant lines induced by high pressure

引用

Science china(Life sciences) 2006年第2期49卷 97-104页

作者： SHEN Sile1,3. WANG Zhenwei3. SHAN Xiaohui2. WANG Hua3. LI Ling3. LIN Xuyun2. LONG Likun2. WENG Kenan4, LIU Bao2.& ZOU Guangtian1 1. National Laboratory of Superhard Materials, Jilin University, Changchun 13.012. china 2. institute of Genetics and Cytology, Northeast Normal University, Changchun 13.02., china 3. College of Life Science, Jilin University, Changchun 13.012. china 4. guangzhou institute of Geochemistry, chinese academy of sciences, guangzhou 510640, china 1. National Laboratory of Superhard Materials Jilin University Changchun 130012 China 3. College of Life Science Jilin University Changchun 130012 China 2. institute of Genetics and Cytology Northeast Normal University Changchun 130024 China 4. guangzhou institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

By using high-pressure treatment, two mutant lines were obtained from agenetically stable japonica rice cultivar Bijing3.. Genomic DNA of the mutant lines, together withthe original line (Bijing3.), was either undigested or digested by Hpa ⅡIMspⅠ, and then subjectedto molecular analysis using two markers, ISSR and RAPD. Results indicated that changes in the PCRamplification profiles of both markers are apparent in the two mutant lines compared with theoriginal rice cultivar, suggesting that there had been both sequence changes and DNA methylationmodifications in the mutant lines. Southern blot analysis using diverse sequences, including twocellular genes (S2.and S3., a set of retrotransposons (Osr7, Osr3., Tos19 and more), and a MITEtransposon family (mPing and Pong), confirmed the results, and indicated that changes in DNAmethylation pattern, genomic structure, and possible activation of some transposons indeed occurredin the mutant lines. Moreover, these changes are stably maintained through selfed generations and indifferent organs. Thus, our results indicate that it is possible to obtain stable mutants in riceby high pressure treatments, and the molecular basis of the mutants may include both genetic andepigenetic changes. Therefore, high hydrostatic pressure seems a promising approach for plantmutagenesis.

关键词： DNA methylation, genomic changes, high pressure, mutagenesis, rice.

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

Debris Flow Hazard Assessment Based on Support Vector Machine

引用

Wuhan University Journal of Natural sciences 2006年第4期11卷 897-900页

作者： YUAN Lifeng 1, 2., ZHANG Youshui 3. 1. institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, Sichuan,{2. 2. Graduate University of chinese academy of sciences, Beijing 100049,{2. 3. institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, Beijing 100101,{2. institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate University of chinese academy of sciences 100049 Beijing China institute of Geographical sciences Natural Resources Research Chinese Academy of Sciences 100101 Beijing China

Seven factors, including the maximum volume of once flow , occurrence frequency of debris flow , watershed area , main channel length , watershed relative height difference , valley incision density and the length ratio of sediment supplement are chosen as evaluation factors of debris flow hazard degree. Using support vector machine （SVM） theory, we selected 2.9 basic data of 3. debris flow channels in Yunnan Province as learning samples in this study. We create a debris flow hazard assessment model based on SVM. The model was validated though instance applications and showed encouraging results.

关键词： debris flow hazard assessment support vector machine (SVM)

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

Geochemical simulation of the formation of brine and salt minerals based on Pitzer model in Caka Salt Lake

引用

Science china Earth sciences 2004年第8期47卷 720-726页

作者： LIU Xingqi1, CAI Keqin2.& YU Shengsong3.1. Nanjing institute of Geography and Limnology, chinese academy of sciences, Nanjing 2.0008,{2. 2.{2. University of Geosciences, Beijing 100083.{2. 3. institute of Salt Lakes, chinese academy of sciences, Xining 810008,{2. 1. Nanjing institute of Geography and Limnology Chinese Academy of Sciences 210008 Nanjing China 2. china University of Geosciences 100083 Beijing China 3. institute of Salt Lakes Chinese Academy of Sciences 810008 Xining China

The geochemical simulation of the formation of brine and salt minerals based on Pitzer model was made in Caka Salt Lake. The evolution of the mixed surface-water and the mineral sequences were calculated and compared with the hydrochemical compositions of the brine and the salt minerals of the deposit in Caka Salt Lake. The results show that the formation temperature of the lake is between 0°C and 5°C, which is well identical with other studies. The mixing of salt-karst water with the surface waters, neglected by the former researchers, is very important to the formation of the lake, indicating that the initial waters resulting in the formation of the lake are multi-source. It is the first time to use Pitzer model in china for making geochemical simulation of the formation and evolution of inland salt lake and satisfactory results have been achieved.

关键词： Pitzer model,Caka Salt Lake,geochemical simulation,salt-karst water.

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

Physical mechanisms of plant roots affecting weathering and leaching of loess soil

引用

Science china Earth sciences 2006年第9期49卷 1002-1008页

作者： LI Yong1,2. ZHANG Qingwen1,2. WAN Guojiang3. HUANG Ronggui3. PIAO Hechun3. BAI Lingyu2.& LI Lu2.1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, institute of Soil and Water Conservation, chinese academy of sciences, Yangling 712.00,{2. 2. institute of Agro-Environment and Sustainable Development, chinese academy of Agricultural sciences, Beijing 100081,{2. 3. institute of Geochemistry, chinese academy of sciences, Guiyang 550002.{2. 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling 712100 China 2. institute of Agro-Environment and Sustainable Development Chinese Academy of Agricultural Sciences Beijing 100081 China 3. institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Plant roots have potential impacts on soil mineral weathering and *** objective is to understand the physical mechanisms of plant roots affecting weathering andleaching of loess soil. Root densities were measured through the method of a large-size dug profile,and transport fluxes of soil elements were determined using an undisturbed monolith soilinfiltration device on the hilly and gully regions of the chinese Loess Plateau. The results showthat the improvement effects of soil environment by plant roots are mainly controlled by the densityand weight of the fibrous roots with the diameters less than 1 mm. Plant roots have the strongereffects on soil physical properties than chemical properties. The principal components analysis(PCA) indicates that soil physical properties by plant roots account for 56.7% of variations in soilenvironment whereas soil chemical properties and pH contribute about 2..2. of the soil *** roles of plant roots in controlling soil weathering and leaching increased in the followingorder: infiltration enhancement > increase of bio-active substance > stabilization of soilstructure. The effects of plant roots on soil mineral weathering and leaching can be quantifiedusing the multiple regression models with the high prediction accuracies developed in this study.

关键词： plant roots, soil weathering and leaching rates, soil environment field, principal components analysis (PCA), chinese Loess Plateau.

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 properties on multivariate filter banks with a matrix factorization

引用

Progress in Natural Science:Materials International 2005年第2期15卷 20-30页

作者： LIAN Qiaofang1, XIAO Hongying2. and CHEN Qiuhui3.1. Department of Mathematics, Beijing Jiaotong University, Beijing 100044, china 2. {3. of Mathematics, {2. of Mathematics and System sciences, chinese academy of sciences, Beijing 100080, china 3. Department of Scientific Computing and Computer Applications, Zhongshan University, guangzhou 5102.5, china) Department of Mathematics Beijing Jiaotong University Beijing 100044 China. institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China. Department of Scientific Computing and Computer Applications Zhongshan University Guangzhou 510275 China

A class of multivariate filter banks with a matrix factorization has been developed by Chen et al. The main purpose of this paper is to discuss some further properties of this kind of filter bank, such as the completeness, accuracy of the corresponding scaling functions and the relationships with Daubechies' wavelets and the multi-wavelets provided by Chui and Lian. Moreover, some examples are given to show that this kind of filter bank has a higher accuracy for the scaling functions.

关键词： filter banks completeness accuracy matrix factorization

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

Synchrotron radiation X-ray diffraction in situ study of fine-grained minerals in shock veins of Suizhou meteorite

引用

Science china Earth sciences 2005年第6期48卷 815-821页

作者： XIE Xiande1, SHU Jinfu2.& CHEN Ming1 1. guangzhou institute of Geochemistry,{2., guangzhou 510640, china 2. Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC, 2.015, USA Correspondence should be addressed to Xie Xiande 1. guangzhou institute of Geochemistry Chinese Academy of Sciences 510640 Guangzhou China 2. Geophysical Laboratory Carnegie Institution of Washington 20015 Washington DC USA

The synchrotron radiation X-ray diffraction technique developed for in situ study ahigh pressure and temperature has also been used to investigate microscopic mineral inclusionsin ultrahigh-pressure metamorphic rocks and deep-mantle samples. Present study added twomore examples of successful utilization of synchrotron radiation X-ray diffraction technique for insitu investigations of fine-grained (0.5―3. μm in size) minerals in very thin shock melt veins othe Suizhou meteorite: ( i ) X-ray diffraction measurement of extremely small-sized vein matrixminerals, and (ii) identification of the micron-sized new mineral tuite embedded in the vein matrixIt has been revealed that the fine-grained vein matrix consists of well crystallized garnet, kamacite and troilite, and the powder diffraction pattern consisting of 17 lines with d-values, intensities( I ), relative intensities (I/Io) and Miller indices, as well as the cell parameters for the new mineratuite has also been successfully obtained. The result of present investigations has enriched thecontent of dynamic high-pressure mineralogy and that of Earth’s mantle geochemistry.

关键词： synchrotron radiation, X-ray diffraction, fine-grained minerals, Suizhou meteorite.

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

中国科学院青岛生物能源与过程研究所2.2.年度“十大工作进展”

引用

高科技与产业化 2024年第9期30卷 20-23页

作者： Qingdao institute of Bioenergy and Process, chinese academy of sciences 中国科学院青岛生物能源与过程研究所

2.2.年,中国科学院青岛生物能源与过程研究所驰骋奋发、勇毅前行,紧紧围绕“四个率先”和“两加快一努力”的目标要求,进一步强化国家战略科技力量主力军使命担当,共同绘就了研究所繁荣发展的辉煌历程,各项事业取得可喜进展。

关键词：中国科学院生物能源工作进展使命担当研究所主力军辉煌历程青岛

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 and application of automatic deformation monitoring data for buildings and structures of mining area

引用

中国有色金属学会会刊：英文版 2011年第S3期21卷 516-522页

作者： XIAO Jie1, 2. 3. ZHANG Jin4 1. institute of Geodesy and Geophysics, chinese academy of sciences, Wuhan 43.077,{2. 2. Key Laboratory of Dynamic Geodesy, institute of Geodesy and Geophysics, chinese academy of sciences, Wuhan 43.077,{2. 3. Graduate School of chinese academy of sciences, Beijing 100049,{2. 4. Department of Surveying and Mapping, Taiyuan University of Technology, Taiyuan 03.02.,{2. Taiyuan Univ Technol Dept Surveying & Mapping Taiyuan 030024 Peoples R China chinese Acad Sci Inst Geodesy & Geophys Key Lab Dynam Geodesy Wuhan 430077 Peoples R China chinese Acad Sci Grad Sch Beijing 100049 Peoples R China

The buildings and structures of mines were monitored automatically using modern surveying technology. Through the analysis of the monitoring data, the deformation characteristics were found out from three aspects containing points, lines and regions, which play an important role in understanding the stable state of buildings and structures. The stability and deformation of monitoring points were analysed, and time-series data of monitoring points were denoised with wavelet analysis and Kalman filtering, and exponent function and periodic function were used to get the ideal deformation trend model of monitoring points. Through calculating the monitoring data obtained, analyzing the deformation trend, and cognizing the deformation regularity, it can better service mine safety production and decision-making.

关键词： wavelet analysis Kalman filtering deformation monitoring data analysis mine

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

Gas hydrate fast nucleation from melting ice and quiescent growth along vertical heat transfer tube

引用

Science china Chemistry 2005年第1期48卷 75-82页

作者： XIE Yingming1,2. GUO Kaihua2. LIANG Deqing2. FAN Shuanshi2. GU Jianming1 & CHEN Jinggui2.1. institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 2.003., china 2. {2. institute of Energy Conversion, The chinese academy of sciences, guangzhou 510640, china 1. institute of Refrigeration and Cryogenics Shanghai Jiaotong University 200030 Shanghai China 2. guangzhou institute of Energy Conversion The Chinese Academy of Sciences 510640 Guangzhou China

During the observation of HCFC141b gas hydrate growth processes outside a ver- tical heat transfer tube, two exciting phenomena were found: fast nucleation of gas hydrate from melting ice, and the spontaneous permeation of water into the guest phases along the surface of heat transfer tube to form gas hydrate continuously. These two phenomena were explained with Zhou & Sloan’s hypothesis and the theory of surface free energy respectively, and a novel method of gas hydrate formation was presented——gas hydrate fast nucleation from melting ice and quiescent growth along heat transfer tube. There is no mechanic stirring in this method, the formed gas hydrates are compact, the ratio of unreacted interstitial water is little, which overcome the drawback of high energy cost and high ratio of unreacted interstitial water among the formed gas hydrates in the system with mechanic stirring. This finding will benefit the gas hydrate ap- plication technologies such as natural gas storage technology or cool storage technology with gas hydrate.

关键词： gas hydrate, natural gas storage, cool storage, fast nucleation from melting ice, permeation, surface free energy.

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：