检索结果-南通市图书馆

The response of electron transport mediated by active NADPH dehydrogenase complexes to heat stress in the cyanobacterium Synechocystis 6803

引用

Science china(life {2.) 2008年第12期51卷 1082-1087页

作者： MA WeiMin, WEI LanZhen & WANG QuanXi college of life and {2. sciences, Shanghai normal university, Shanghai 2.02.4, china 1. college of life and {2. sciences Shanghai Normal University Shanghai 200234 China

The electron-transport machinery in photosynthetic membranes is known to be very sensitive to heat. In this study, the rate of electron transport (ETR) driven by photosystem I (PSI) and photosystem II (PSII) during heat stress in the wild-type Synechocystis sp. strain PCC 6803 (WT) and its ndh gene inactiva-tion mutants △ndhB (M55) and △ndhD1/ndhD2.(D1/D2. was simultaneously assessed by using the novel Dual-PAM-100 measuring system. The rate of electron transport driven by the photosystems (ETRPSs) in the WT, M55, and D1/D2.cells incubated at 30℃ and at 55℃ for 10 min was compared. Incubation at 55 ℃ for 10 min significantly inhibited PSII-driven ETR (ETRPSII) in the WT, M55 and D1/D2.cells, and the ex-tent of inhibition in both the M55 and D1/D2.cells was greater than that in the WT cells. Further, PSI-driven ETR (ETRPSI) was stimulated in both the WT and D1/D2.cells, and this rate was increased to a greater extent in the D1/D2.than in the WT cells. However, ETRPSI was considerably inhibited in the M55 cells. Analysis of the effect of heat stress on ETRPSs with regard to the alterations in the 2.active NDH-1 complexes in the WT, M55, and D1/D2.cells indicated that the active NDH-1 supercomplex and medi-umcomplex are essential for alleviating the heat-induced inhibition of ETRPSII and for accelerating the heat-induced stimulation of ETRPSI, respectively. Further, it is believed that these effects are most likely brought about by the electron transport mediated by each of these 2.active NDH-1 complexes.

关键词： active NDH-1 complexes heat response photosystems-driven electron transport Synechocystis 6803

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

Clonal diversity of Clintonia udensis *** Mey. populations and its correlation with ecological factors

引用

Science china(life {2.) 2008年第7期51卷 575-576,578-582页

作者： WANG YiLing 1,2.,LI Xin 1 ,GUO Jing 1 ,GUO ZhiGang 1 &ZHAO GuiFang 1 1Key Laboratory of Resource Biology and Biotechnology in Western china(Ministry of Education),college of {2. sciences, Northwest university,Xi’an 710069,china 2.1} of {2. sciences,Shanxi normal university,Linfen 041004,china 1. Key Laboratory of Resource Biology and Biotechnology in Western china (Ministry of Education) College of Life Sciences Northwest University Xi’an 710069 China 2. college of life {2. Shanxi Normal University Linfen 041004 China

The clonal diversity of Clintonia udensis *** *** detected by ISSR markers among 16 populations,and its correlation with ecological factors was analyzed as well in this *** showed that individuals(clonal ramets)per genotype were 1.12.and 1.149 at population and species levels,respectively,and that the 16 populations were all *** detected genotypes were localized,without exception,within populations but demonstrated relatively high clonal differentiation among *** clonal diversity of the studied populations was high,with the average Simpson's index of 0.975,while the genets showed a clonal architecture of"guerilla".The population genetic diversities revealed by genet were consistent with those by ramet,further confirming their genetic differentiation among *** its genotype diversity within populations probably resulted largely from the frequent seedling regeneration and *** addition,the correlation analysis further revealed that,among the ecological factors,Simpson's index of *** had a significant positive correlation(P<0.05)with pH values in the soil but not others.

关键词： Clintonia udensis Trautv.et Mey. population clonal diversity ecological factors correlation

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

Theory of truth degrees of propositions in the logic system Ln^＊

引用

Science in china(Series F) 2006年第4期49卷 471-483页

作者： LI Jun1,2.& WANG Guojun1,3 1. Institute of Mathematics, Shaanxi normal university, Xi’an 7{2.62. china 2. School of sciences, Lanzhou university of Technology, Lanzhou 730050, china 3. Research Center for Science, Xi’an Jiaotong university, Xi’an 7{2.49, china 1. Institute of Mathematics Shaanxi Normal University Xi’an 710062 China 2. School of sciences Lanzhou University of Technology Lanzhou 730050 China 3. Research Center for Science Xi’an Jiaotong University Xi’an 710049 China

By means of infinite product of uniformly distributed probability spaces of cardinal n the concept of truth degrees of propositions in the n-valued generalized Lu- kasiewicz propositional logic system Ln^＊ is introduced in the present paper. It is proved that the set consisting of truth degrees of all formulas is dense in [0,1], and a general expres- sion of truth degrees of formulas as well as a deduction rule of truth degrees is then obtained. Moreover, similarity degrees among formulas are proposed and a pseudo-metric is defined therefrom on the set of formulas, and hence a possible framework suitable for developing approximate reasoning theory in n-valued generalized Lukasiewicz propositional logic is established.

关键词： truth degree similarity degree approximate reasoning.

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

Calculating soil moisture by remote sensing and analyzing hydrologic cycle process in the Yellow River basin

引用

Science china(Technological sciences) 2004年第z1期47卷 1-13页

作者： YANG Shengtian1 & LIU Changming1, 2.1. School of environmental sciences, Beijing {2. university, Beijing 100875, china 2. Institute of Geographic Science and Natural Resources Research, Beijing 100101, china Beijing normal Univ Sch Environm Sci Beijing 100875 Peoples R China Inst Geog Sci & Nat Resources Beijing 100101 Peoples R China

Based on the AVHRR pathfinder remote sensing data, soil moisture, precipitation and evaporation during the period of 1982.1998, soil moisture of all layers of soil-profile (0—1 m) in the Yellow River basin over the 17 years are calculated by the remote sensing model of calculating soil water. The Yellow River basin is divided into seven subcatchments as control sections at the location of six hydrologic stations (Lanzhou, Toudaoguai, Longmen, Sanmenxia, Huayuankou and Lijin). After calculating soil moisture and obtaining runoff data and precipitation data, the dynamical features of hydrological cycle in the Yellow River basin are analyzed for the period from 1982.to 1988 using water balance method. The conclusions are as follows: It is feasible to calculate the soil water on the macro-scale, in the soil profile with temporal continuity by means of remote sensing and survey in land. Some values of the key water cycle factors in the Yellow River are obtained, which include the annual precipitation of 4000 km3, the evapotranspiration of 3000-3500 km3, and the soil moisture transformation of ?500- 500 km3. Consequently, we analyzed the process of the water cycle in the Yellow River over the 17 years, and the results show that the segment upstream of Lanzhou city is a relatively humid region, and the area of internal waters and the reaches of Shanshan is the most desiccated region. Therefore, the runoff in the depth process is intensive and the runoff-generating process is weak in more arid regions.

关键词： the Yellow River, soil moisture, remote sensing, hydrologic cycle.

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 high-resolution late Pleistocene record of pollen vegetation and climate change from Jingning, NW china

引用

Science china Earth sciences 2006年第2期49卷 154-162页

作者： LI Chunhai12. TANG Lingyu1, FENG Zhaodong3,4, ZHANG Hucai2. WANG Weiguo3 & AN Chenbang3 1. Nanjing Institute of Geology and Palaeontology, Chinese Academy of sciences, Nanjing 2.1}08, {2. 2. Nanjng Institute of Geography and Limnology, Chinese Academy of sciences, Nanjing 2.1}08, {2. 3. environment and Resources college, Lanzhou university, Lanzhou 730000, {2. 4. Beijing normal university, Beijing 100875, {2. 1. Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China 2. Nanjng Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China 3. environment and Resources college Lanzhou University Lanzhou 730000 China 4. Beijing normal university Beijing 100875 China

With the support of 18 AMS-14C data, a high-resolution pollen record from the Suancigou section at Jingning, Gansu Province was established. Our results showed that the vegetation ex-perienced a series of changes characterized by the alternative growth and decline of forest and steppe components during the period from 44.2.to 11 ka B.P. in the Jingning area. Over the period of 44―2. ka B.P. (MIS3), coniferous forests were flourishing, indicating a humid climate with the tem-perature being lower than that of the present. Since 2. ka B.P., the vegetation was dominated by steppe-desert steppe under a cold and dry condition, and entered the Last Glacial Maximum domi-nated by desert steppe. Several periods of the marked decrease in the arborous pollen content in Suancigou well corresponded to the North Atlantic Heinrich events, especially to Heinrich event 3, further supporting that the Heinrich events were well reflected by the pollen record in the Loess Pla-teau as well.

关键词： Western Loess Plateau, pollen record, climatic change, late Pleistocene.

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

Comparison of temporal and Spatial Characteristics of Ozone Pollution at Ground Level in the Eastern china

引用

Chinese Journal of Population,Resources and environment 2006年第3期4卷 51-57页

作者： Liu Houfeng1,2.1. Shandong normal university, Jinan 2.0014, {2. 2. Chinese Research Academe of environmental sciences, Beijing 100012. {2. Shandong normal university Jinan 250014 China Chinese Research Academe of environmental sciences Beijing 100012 China

Monitoring data from ozone（O3） automatic stations in three typical cities with different climatic areas in the southern and northern parts of eastern china are used to analyze temporal and spatial characteristics of ozone pollution at ground level. The results show that ozone pollution level has distinct regional differences and the concentration in the suburbs is higher than that in the urban areas. The seasonal variation of ozone concentration in different climatic areas is greatly affected by the variation of precipitation. Ozone concentration in Shenyang and Beijing , in the temperate zone, has one perennial peak concentration, occurring in early summer, May or June. Ozone concentration in Guangzhou, in sub-tropical zone, has two peak values year round. The highest values occur in October and the secondary high value in June. The ozone season in the south is longer than that in the north. The annual average daily peak value of ozone concentrations in different climates usually occur around 3 pm. The diurnal variation range of ozone concentration declines with the increase of latitude. Ozone concentration does not elevate with the increase of traffic flow. Ozone concentration in Guangzhou has a distinct reverse relation to CO and NOx. This complicated non-linearity indicates that the equilibrium of ozone photochemical reaction has regional differences. Exceeding the rate of Beijing＇s lh ozone concentration is higher than that of Guangzhou, whereas the average 8h ozone level is lower than that of Guangzhou, indicating that areas in low latitude are more easily affected by moderate ozone concentrations and longer exposure. Thus, china should work out standards for 8h ozone concentration.

关键词： ozone temporal and spatial characteristics 8h concentrations weekly variation

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 laser pulse on the photoabsorption spectra of Li atom in strong external field

引用

Science china(Physics,Mechanics & Astronomy) 2006年第2期49卷 178-186页

作者： WANG Dehua1 & LIN Shenglu2.1. School of Physics and Electronic Engineering, Yantai normal university, Yantai 2.402., {2. 2. Department of Physics, Shandong normal university, Jinan 2.0014, {2. 1. School of Physics and Electronic Engineering Yantai Normal University Yantai 264025 China 2. Department of Physics Shandong Normal University Jinan 250014 China

Using the time-dependent perturbation theory and the calculation formula of the single- and double-pulse absorption spectra of the atom in strong external fields, we calculate the single- and double-pulse absorption spectra of Li atom in strong magnetic field for different pulse widths. The results show that a pulse of some width can reduce the contribution of the short period closed orbits and eliminate the contribution of the long period orbits. Compared with the single-pulse absorption spectra, we found that for some phase differences, the double-pulse laser absorption spectra are strengthened; while for others, they are reduced. Therefore, we can use the pulse laser to control the oscillation of the absorption spectra and obtain the optimization object.

关键词： laser pulse closed orbit absorption spectra.

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

Density functional study on enantioselective reduction of keto oxime ether with borane catalyzed by oxazaborolidine

引用

Science china Chemistry 2006年第4期49卷 296-307页

作者： LI Ming1, ZHENG Wenxu2.& TIAN Anmin2.1. Department of Chemistry, Southwest-china normal {2., Chongqing 400715, china 2. Department of Chemistry, Sichuan {2., Chengdu 610064, china 1. Department of Chemistry Southwest-China Normal University Chongqing 400715 China 2. Department of Chemistry Sichuan University Chengdu 610064 China

The enantioselective reduction of keto oxime ether with borane catalyzed by oxazaborolidine is discussed by the density functional theory (DFT) method. The main intermediates and transition states for this reaction are optimized completely at the B3LYP/6-31g(d) level, and the transition states are verified by vibrational modes. As shown, the chirality-controlled steps for this re- action are the hydride transfer from borane to carbonyl carbon and oxime carbon of keto oxime ether, and the chirality for the reduced products is determined in these two reaction steps. In all examined reaction paths, the first hydride is transferred via a six-membered ring and the second hydride via a five-membered ring or a four-membered ring.

关键词： keto oxime ether, oxazaborolidine, enantioselective reduction, DFT.

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

Weighted composition operators between μ-Bloch spaces on the unit ball

引用

Science china Mathematics 2005年第10期48卷 1349-1368页

作者： ZHANG Xuejun~1 & XIAO Jianbin~2.1. college of Mathematics and Computer Science,Hunan normal {2.,Changsha 410006,china(email:xuejunttt@2.3. net) 2. The School of Science,Hangzhou Dianzi {2.,Hangzhou 310037,china 1. college of Mathematics and Computer Science Hunan Normal University 410006 Changsha China 2. The School of Science Hangzhou Dianzi University 310037 Hangzhou China

In this paper,necessary and sufficient conditions are given for the weighted composition operator T_(ψ,ψ) to be bounded or compact from the space β_μ to β_ν (or β_(μ,0) to β_(ν,0) ) on the unit ball of C^***... 详细信息

关键词： μ-Bloch space, weighted composition operator, boundedness, compactness.

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

Microstructure and Element Composition of Shell Plates of Liolophura japonica

引用

Wuhan university Journal of Natural sciences 2010年第2期15卷 176-184页

作者： CHEN Daohai1,2.1. college of Fisheries, Ocean university of {2., Qingdao 2.6003, Shangdong, {2. 2. life Science and Technology School, Zhanjiang normal university, Zhanjiang 52.048, Guangdong, {2. college of Fisheries Ocean University of China Qingdao China life Science and Technology School Zhanjiang Normal University Zhanjiang China

The microstructure characteristics of shell plates of chiton Liolophura japonica Lischke were analyzed using environmental scanning electron microscopy （ESEM）. The results show that the internal structure of the shell plate of chiton Liolophurajaponica is composed of seven calcium layers which were crossed lamellar crystallites, homoge- neous structure, granular crystallites, and trabecular type crystallites. The element compositions of shell plates were analyzed using X-ray photoelectron spectroscopy （XPS）. The results determined by XPS show that the surface chemical states of various layers are different. There are 13 elements （Na, O, N, C, S, P, Ca, C1, Si, A1, K, Fe, Mg） on the shell plate of chiton L. japonica. Among the 13 elements, 11 are on the outside pigment layer except K and S. Among seven layers of shell plate, there is the largest quantity of elements on the outside pigment layer, and the least quantity of elements is on layer C （Articulamentum auctorum）. There are 7 elements on the layer C （Articulamentum auctorum）. Be- sides calcium carbonate, there are some inorganic compounds on the shell plate, such as NaC1, MgO, A12.3, silicate, sulfate and phosphate. There are some organic chemical components, such as carbohydrate, organic sulfide, and organic nitride on the shell plates.

关键词： Liolophura japonica environmental scanning electron microscope X-ray photoelectron spectroscopy (XPS) microstructure of shell plate

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：