检索结果-南通市图书馆

Change of surface cover greenness in China between 2000 and 2010

Chinese science Bulletin 2012年第22期57卷 2835-2845页

作者： LIU Shuang1,4& GONG Peng1,2,31State Key Laboratory of Remote Sensing science, Jointly Sponsored by Institute of Remote Sensing Applications of Chinese Academy of sciences,and Beijing Normal university, Beijing 100101, China 2Institute for Global Change Studies & Center for Earth System science, Tsinghua university, Beijing 100084, China 3department of environmental science, policy and management, university of california, berkeley, ca9472., usa 4Graduate university of Chinese Academy of sciences, Beijing 100049, China State Key Laboratory of Remote Sensing science Jointly Sponsored by Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing China Graduate university of Chinese Academy of sciences Beijing China Institute for Global Change Studies & Center for Earth System science Tsinghua University Beijing China department of environmental science Policy and Management University of California Berkeley USA

Surface greenness reflects the situation of vegetation *** index calculated from the Red and Near Infrared bands of remote sensing images,whose values indicate the level of photosynthetic activity,is monotonically related to surface greenness when vegetation canopy does not fully cover the background *** for desert regions,vegetation index is positively correlated with vegetation ***,vegetation index can be used to study the change in greenness of desert *** study collected MODIS Normalized Difference Vegetation Index (NDVI) data from 2000 to 2010 and analyzed their change over China in this *** results showed that an increasing trend of NDVI occurred over 66.84% (OLS fitting) or 64.27% (LAD fitting) of China,indicating that China's greenness is increasing ***,desertification of China *** showing large increase in greenness are found in Shaanxi,Shanxi,Ningxia,Henan,Shandong,Qinghai,and Gansu while regions with large decrease in greenness are found in Northeast Inner Mongolia,South Tibet,Jiangsu,and *** of Qinghai,Gansu,Xinjiang and South Tibet could probably be driven by climate *** of greenness in Northeast Inner Mongolia was related to agricultural *** of greenness in Jiangsu and Shanghai was related to rapid *** factors did not exhibit obvious correspondence to the large increase in greenness in Shaanxi,Shanxi,Ningxia and Gansu,indicating that the changes might have been caused by human *** reduction of desert areas in China could probably have been caused by human management and protection at the national scale.

关键词：中国地表覆盖归一化植被指数植被覆盖度沙漠地区 NDVI 西藏南部气候因素

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 Lipidomic Study of the Effects of N-methyl-N′-nitro-N-nitrosoguanidine on Sphingomyelin Metabolism

引用

Acta Biochimica et Biophysica Sinica 2005年第8期37卷 515-524页

作者： Yun HUANG~(&#) Jing SHEN~# Ting WANG Yan-Ke YU Fanqing E CHEN~1 Jun YANG~* department of Pathology and Pathophysiology,Center for environmental Genomics Zhejiang university School of Medicine,Hangzhou 310031,China ~1 Molecular Biology Branch.Life science Division,Lawrence berkeley National Laboratory,university of california at berkeley,berkeley,ca 94720,usa department of Chemistry,Georgia State university.Atlanta,GA 30303.usa department of Pathology and Pathophysiology Center for Environmental Genomics Zhejiang University School of MedicineHangzhou 310031 China Molecular Biology Branch Life Science Division Lawrence Berkeley National Laboratory University of California at BerkeleyBerkeley CA 94720 USA

Systems biology is a new and rapidly developing research area in which,by quantitativelydescribing the interaction among all the individual components of a cell,a systems-level understanding of abiological response can be ***,it requires high-throughput measurement technologies forbiological molecules,such as genomic and proteomic approaches for DNA/RNA and protein,***,a new concept,lipidomics,which utilizes the mass spectrometry(MS)method for lipid analysis,has been *** this lipidomic approach,the effects of N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)on sphingomyelin metabolism,a major class of sphingolipids,were *** moleculeswere extracted from cells and analyzed by matrix-assisted laser desorption ionization-time of flight *** found that MNNG induced profound changes in sphingomyelin metabolism,including the appearance ofsome new sphingomyelin species and the disappearance of some others,and the concentrations of severalsphmgomyelin species also *** was accompanied by the redistribution of acid sphingomyelinase(ASM),a key player in sphingomyelin *** the other hand,imipramine,an inhibitor of ASM,caused the accumulation of *** also prevented some of the effects of MNNG,as well as theredistribution of *** together,these data suggested that the lipidomic approach is highly effectivefor the systematic analysis of cellular lipids metabolism.

关键词： lipidomics mass spectrometry ceramide sphingomyelin acid sphingomyelinase

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

Measurement of Thermal Expansion Coefficients with Holographic Technique

引用

Journal of Thermal science 1995年第1期4卷 67-74页

作者： Zhifeng Zhang(department of Mechanical and environmental Engineering, university of california at Santa Barbara, ca93106, usa) department of Mechanical and environmental Engineering University of California at Santa Barbara USA

A simplified mathematical model was created for measurement of thermal expansion coefficients of thinsheet materials with holographic technique. Experimental set-ups corresponding to the mathematicalmodel were designed and built for both tests above room temperature and at low temperatures. Afringe control technique was introduced for low temperature measurements to compensate rigid bodymovement. Thin sheet specimens of silicon and aluminum alloy (7075) were tested with the developedtechnique. The tested results are in good agreement with reported data and thus verify the validityof the developed technique. The thermal expansion coefficients of the tested materials ranged from2.5×10-6C-1 to 23.6×0-60C-1.

关键词： thermal expansion holographic measurement low temperature tests deformation tests.

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

Macroscopic relationship for preferential flow in the vadose zone:Theory and validation

引用

science China(Technological sciences) 2009年第11期52卷 3264-3269页

作者： LIU HuiHai1 & ZHANG RenDuo2 1 Earth science Division, Lawrence berkeley National Laboratory, berkeley, ca 947200, usa 2 School of environmental science and Engineering, Sun Yat-sen university, Guangzhou 510275, China Earth science Division Lawrence Berkeley National Laboratory Berkeley USA School of environmental science and Engineering Sun Yat-sen University Guangzhou China

Preferential flow commonly observed in unsaturated soils allows rapid movement of solute from the ground surface or vadose zone to the groundwater, bypassing a significant volume of unsaturated soil and increasing the risk of groundwater contamination. A variety of evidence indicates that complex preferential flow patterns observed from fields are fractals. This paper discusses a macroscopic relationship for modeling preferential flow in the vadose zone. Conceptually, the flow domain can be divided into active and inactive regions. Flow occurs preferentially in the active region (characterized by fractals), and inactive region is simply bypassed. The portion of the active region was found to be a power function of saturation. The validity of this macroscopic relationship is demonstrated by its consistency with field observations and the related numerical experiments.

关键词： preferential flow constitutive relations vadose zone hydrology

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 Spectral Index for Estimating Soil Salinity in the Yellow River Delta Region of China Using EO-1 Hyperion Data

引用

Pedosphere 2010年第3期20卷 378-388页

作者： WENG Yong-Ling GONG Peng ZHU Zhi-Liang department of Surveying and Mapping Engineering College of Transportation Southeast University Nanjing 210096(China) State Key Laboratory of Remote Sensing science Institute of Remote Sensing Applications of the Chinese Academy ofSciences and Beijing Normal University Beijing 100101 (China) department of Environment science Policy and Management University of California Berkeley CA 94720 (USA) EROS Data Center U.S. Geological Survey Sioux Falls SD 57198 (USA)

Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory and hyperspectral data were acquired from an EO-1 Hyperion sensor to quantitatively map soil salinity in the region. A soil salinity spectral index (SSI) was constructed from continuum-removed reflectance (CR-reflectance) at 2052 and 2203 nm, to analyze the spectral absorption features of the salt-affected soils. There existed a strong correlation (r = 0.91) between the SSI and soil salt content (SSC). Then, a model for estimation of SSC with SSI was established using univariate regression and validation of the model yielded a root mean square error (RMSE) of 0.986 and an R2 of 0.873. The model was applied to a Hyperion reflectance image on a pixel-by-pixel basis and the resulting quantitative salinity map was validated successfully with RMSE = 1.921 and R2 = 0.627. These suggested that the satellite hyperspectral data had the potential for predicting SSC in a large area.

关键词： hyperspectral reflectance soil salt content spectral absorption features

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

Interaction mechanisms of organic contaminants with burned straw ash charcoal

引用

Journal of environmental sciences 2010年第10期22卷 1586-1594页

作者： Wenhai Huang,Baoliang Chen department of environmental science,Zhejiang university,Hangzhou 310028,China department of environmental science Zhejiang University Hangzhou 310028 China

Black carbons （e.g., charcoal） have a great impact on the transport of organic contaminants in soil and water because of its strong affinity and ubiquity in the environment. To further elucidate their interaction mechanism, sorption of polar （p-nitrotoluene, m-dinitrobenzene and nitrobenzene） and nonpolar （naphthalene） aromatic contaminants to burned straw ash charcoal under different de-ashed treatments were investigated. The sorption isotherms fitted well with Freundlich equation, and the Freundlich N values were all around 0.31-0.38, being independent of the sorbate properties and sorbent types. After sequential removal of ashes by acid treatments （HCl and HCl-HF）, both adsorption and partition were enhanced due to the enrichment of charcoal component. The separated contribution of adsorption and partition to total sorption were quantified. The effective carbon content in ash charcoal functioned as adsorption sites, partition phases, and hybrid regions with adsorption and partition were conceptualized and calculated. The hybrid regions increased obviously after de-ashed treatment. The linear relationships of Freundlich N values with the charring-temperature of charcoal or biochar （the charred byproduct in biomass pyrolysis） were observed based on the current study and the cited publications which included 15 different temperatures （100-850℃）, 10 kinds of precursors of charcoal/biochar, and 10 organic sorbates.

关键词： ash charcoal organic pollutant adsorption partition effective carbon

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

Principle of small target detection for hyperspectral imagery

引用

science China Earth sciences 2007年第8期50卷 1225-1231页

作者： GENG XiuRui1,2,3 & ZHAO YongChao2,3,4 1 Research Center for Remote Sensing and GIS, department of Geography, Beijing Normal university, Beijing 100875, China 2 State Key Laboratory of Remote Sensing science, Chinese Academy of sciences, Beijing 100101, China 3 Institute of Erectronics, Chinese Academy of sciences, Beijing 100080, China 4 Center for for Assessment and Monitoring of Forest and environmental Resources and Division of Ecosystem sciences university of california berkeley, ca 94720-3114, usa Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing China State Key Laboratory of Remote Sensing science Chinese Academy of Sciences Beijing China Institute of Erectronics Chinese Academy of Sciences Beijing China Center for for Assessment and Monitoring of Forest and environmental Resources and Division of Ecosystem sciences University of California Berkeley USA

This paper generalizes the progress of algorithms in small target detection for hyperspectral imaging, and finds that whitening the image is the key point of many methods in small target detection. An al-gorithm is presented to detect desired targets by converting large targets into small ones based on the weighted sample autocorrelation matrix.

关键词： hyperspectral whiten target detection

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

Effect of background electrolytes on the adsorption of nitroaromatic compounds onto bentonite

引用

Journal of environmental sciences 2009年第8期21卷 1044-1052页

作者： CHEN Baoliang, HUANG Wenhai department of environmental science, Zhejiang university, Hangzhou 310028, Zhejiang, China. department of environmental science Zhejiang University Hangzhou 310028 Zhejiang China

To further elucidate interaction of nitroaromatic compounds with mineral surface, the sorption of m-dinitrobenzene （m-DNB） and nitrobenzene to original bentonite in aqueous solution containing different electrolytes （i.e., KCl, NH4Cl, caCl2 and Tetramethylammonium bromide （TMAB）） was studied. The sorption of m-DNB was greatly enhanced with the presence of KCl and NH4Cl, while little influence was observed with caCl2 and TMAB, following the order of KCl 〉 NH4Cl 〉〉 TMAB, caCl2, or DI water. For nitrobenzene, sorption enhancement only occurred at high nitrobenzene concentrations in the presence of KCl, and the solute equilibrium concentration at inflexion point was lowered with increasing KCl concentration. These sorption enhancements were significantly promoted with the increase of electrolyte concentration. The salting-out effect is insufficient to account for the sorption enhancement by original bentonite with increasing KCI or NH4Cl concentration. X-ray diffraction patterns of bentonite suspensions indicated that the sorption enhancement of m-DNB was attributed to the intercalation of K^＋ or NH4^＋ into bentonite interlayer and then dehydration with m-DNB to form inner-sphere complexes, which caused previously expanded bentonite interlayers to collapse in aqueous suspension, thus further enhanced the interaction of phenyl with siloxane surface. In comparison, the sorption enhancement of NB is attributed to the formation of outer-sphere complexes with K^＋ at high solute-loadings （〉 20（0-400 mg/kg）. The sorption of m-DNB to initially modified TMA^＋-bentonite and K^＋-bentonite was almost the same as respective sorption to original bentonite in solution containing TMA^＋ and K^＋.

关键词： sorption nitroaromatic compound bentonite cation type wastewater treatment

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

Design of policy mechanism to promote cleaner production in China

引用

Journal of environmental sciences 2001年第3期13卷 346-350页

作者： ZHANG Tian zhu(department of environmental science and Engineering, Tsinghua university, Beijing 100084, China. 清华大学北京 100084

In order to promote cleaner production in China, a package of policy options was presented based on the identification of the barriers encountered in the CP demonstration project and the effectiveness and feasibility of policy options for the CP implementation were analyzed. Furthermore, the policy mechanism framework was given, which composes of compulsory, economic incentive, social pressure and supportive function. Finally, the implementation strategy of the policy mechanism, in which the emphasis will be changed from compulsory policy options towards economic and social pressure policy options, was proposed.

关键词： cleaner production barrier identification policy mechanism China

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

Expression of lignin peroxidase H2 from Phanerochaete chrysosporium by multi-copy recombinant Pichia strain

引用

Journal of environmental sciences 2009年第2期21卷 218-222页

作者： WANG Wei,WEN Xianghua department of environmental science and Engineering,Tsinghua university,Beijing 100084,China. department of environmental science and Engineering Tsinghua University Beijing 100084 China

The lipH2 gene, encoding the expression of lignin peroxidase, was cloned from Phanerochaete chrysosporium BKM-F-1767 and expressed in Pichia pastoris X-33, a yeast. The cDNA of LiPH2 was generated from total RNA extracted from P chrysosporium by PCR with primers that do not contain a P. chrysosporium lignin peroxidase secretion signal. The gene was then successfully inserted into the expression vector pPICZα, and resulted in the recombinant vector pPICZα-lipH2. The transformation was conducted in two ways. One was using the wild Pichia pastoris as the recipients, which results in the recombinant P. pastoris with single or low lipH2 gene copy. The second was using P. pastoris and single or low lipH2 gene copy as the recipients, which results in the recombinant P. pastoris with multi-copies of lipH2 genes. This study firstly expressed the gene lipH2 in P. pastoris and achieved the successful expression of the lipH2 depending upon the generation of a recombinant strain that contained multiple copies. The lignin peroxidase activity reached a maximum of 15 U/L after 12 h induction.

关键词： heterologous expression lignin peroxidase Pichia pastoris

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：