检索结果-南通市图书馆

Relation between seed size in different plant species and response of their seedlings to double CO_2

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第4期42卷 331-333页

作者： DING Li, ZHANG Chonghao, BAI Kezhi and KUANG Tingyun1 department of Biology, beijing normal university,{2., china 2. Institute of Botany, Chinese Academy of Sciences, beijing 100093, china department of Biology Beijing Normal University Beijing China Institute of Botany Chinese Academy of Sciences Beijing China

ATMOSPHERIC CO2.concentration is predicted to increase to 700μL/L by the middle of the 2.st century. The impacts of raising CO2.on vegetation and ecosystem have been intensively studied. It is well known that C3 spec... 详细信息

ATMOSPHERIC CO2./sub> concentration is predicted to increase to 700μL/L by the middle of the 2.st century. The impacts of raising CO2./sub> on vegetation and ecosystem have been intensively studied. It is well known that C3 species and C4 species responded much differently to double CO2./sub>. Potential enhancement of photosynthesis efficiency induced by double CO2./sub> in C3 plants was almost 66%, but in C4 plants only 4%. The response to double CO2./sub> in C3 species might

关键词： double CO2 seed size seedling growth percentage enhancement.

Some scaled limit theorems for an immigration super-Brownian motion

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2008年第2期51卷 203-214页

作者： ZHANG Mei School of Mathematical Sciences,beijing normal {2.,beijing 100875,china School of Mathematical Sciences Beijing Normal University Beijing China

In this paper,the small time limit behaviors for an immigration super-Brownian motion are studied,where the immigration is determined by Lebesgue *** first prove a functional central limit theorem,and then study the l... 详细信息

关键词： super-Brownian motion with immigration functional central limit theorem large deviation moderate deviation 60J80 60F05

Hausdorff measures of the image, graph and level set of bifractional Brownian motion

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2010年第11期53卷 2973-2992页

作者： LUAN NaNa School of Mathematical Sciences, beijing normal university, beijing 100875,{2. School of Mathematical Sciences Beijing Normal University Beijing China

Let BH,K = {BH,K(t), t ∈ R+} be a bifractional Brownian motion in Rd. This process is a selfsimilar Gaussian process depending on two parameters H and K and it constitutes a natural generalization of fractional Brownian motion (which is obtained for K = 1). The exact Hausdorff measures of the image, graph and the level set of BH,K are investigated. The results extend the corresponding results proved by Talagrand and Xiao for fractional Brownian motion.

关键词： bifractional Brownian motion self-similar Gaussian processes image graph level set local time Hausdorff dimension Hausdorff measure

Integrative inversion of land surface component temperature

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第11期48卷 2011-2019页

作者： FAN Wenjie1 & XU Xiru1,2.1. Institute of Remote Sensing and Geographical Information System, Peking university, beijing 100871,{2. 2. Center of Remote Sensing and GIS of beijing normal university, beijing 100875,{2. Institute of Remote Sensing and Geographical Information System Peking University Beijing China Center of Remote Sensing and GIS of beijing normal university Beijing China

In this paper, the row winter wheat was selected as the example to study the com-ponent temperature inversion method of land surface target in detail. The result showed that the structural pattern of row crop can affect the inversion precision of component temperature evi-dently. Choosing appropriate structural pattern of row crop can improve the inversion precision significantly. The iterative method combining inverse matrix was a stable method that was fit for inversing component temperature of land surface target. The result of simulation and field ex-periment showed that the integrative method could remarkably improve the inversion accuracy of the lighted soil surface temperature and the top layer canopy temperature, and enhance inver-sion stability of components temperature. Just two parameters were sufficient for accurate at-mospheric correction of multi-angle and multi-spectral thermal infrared data: atmospheric trans-mittance and the atmospheric upwelling radiance. If the atmospheric parameters and component temperature can be inversed synchronously, the really and truly accurate atmospheric correction can be achieved. The validation using ATSRII data showed that the method was useful.

关键词： components temperature, inverse pattern, atmospheric correction

Effects of PKCa antisense RNA on human breast cancer cell proliferation and expression of cyclinD1 and CDK4

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第12期44卷 1110-1114页

作者： SANG Jianli WANG YongchaoLaboratory of Cell Biology , department of Biology, beijing normal university,{2. , china Laboratory of Cell Biology Department of Biology Beijing Normal University Beijing China

The role of PKCα in human breast cancer cell proliferation and expression of cyclinD1 and CDK4 has been investigated using inhibition of PKCα expression by its antisense RNA. When PKCα expression was inhibited the rate of cell proliferation decreased apparently and the levels of cyclinD1 and CDK4 mRNA were lower than the control. The results showed that PKCα, a key member of signal transduction system, played an important role in human breast cancer cell proliferation and had a close relationship with expression of cyclinD1 and CDK4 which control start of cell cycle.

关键词： breast cancer PKCα cell proliferation cyclinD1 CDK4.

Commutators of pseudo-differential operators

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2008年第3期51卷 453-460页

作者： LIN Yan School of Mathematical Sciences, beijing normal university, beijing 100875,{2. School of Mathematical Sciences Beijing Normal University Beijing China

In this paper, the boundedness of commutators generated by pseudo-differential operators and BMO functions is discussed on Lebesgue spaces.

关键词： pseudo-differential operator BMO function commutator Lebesgue space 42.2. 35S05 47G30

Existence and Application of Optimal Markovian Coupling with Respect to Non-Negative Lower Semi-Continuous Functions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2000年第2期16卷 261-270页

作者： Shaoyi Zhangdepartment of Mathematics.beijing {2. university,beijing 100875,P.R.china department of Mathematics,Hubei {2. university,Huangshi 435002.P.R.china department of Mathematics Beijing Normal University Beijing 100875 P. R. China department of Mathematics Hubei Normal University Huangshi 435002 P. R. China

In this paper,for two given transition probabilities,the existence of the optimal Markovian coupling with respect to a non-negative lower semi-continuous function is *** an application of this result,the well-known Strassen’s theorem is ***,it is proved that the existence of an order-preserving Markovian coupling of two given jump processes is equivalent to their stochastical comparability.

关键词： Transition probability Markovian coupling Jump process

C^(18)O Observations of the Dark Molecular Cloud L134 and Gas Depletion onto Dust

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2005年第2期5卷 144-150页

作者： Xin-Jie Mao and Xiao-Xia Sun department of Astronomy, beijing normal university,{2. maoxj@*** department of Astronomy Beijing Normal University Beijing 100875

We map the dark molecular cloud core of L134 in the C^(18)O (J = 1 - 0)emission line using the PMO 13.7m telescope, and present a contour map of integrated intensity ofC^(18)O (J = 1 - 0) emission. The C^(18)O cloud is inside the distribution of extinction A_B, thevisual extinction of blue light, as well as inside the ^(13)CO cloud in the L134 region. Thedepletion factors in this C^(18)O cloud are generally greater than unity, which means there is gasdepletion onto dust. Since only a minimum A_B - 9.7 mag is available, and our observations measureboth undepleted and depleted regions along the line of sight, the depletion factors could verylikely be larger in the central core than the calculated value. So we conclude that depletion doesoccur in the bulk of the C^(18)O cloud through a comparison between the C^(18)O and blue extinctionmaps in the L134 region. There is no direct evidence as yet for star formation in L134, and so coreson the verge of collapse will not be visible in CO and other gas molecules.

关键词： ISM: clouds ISM: individual (L134) ISM: molecules ISM: extinction

A Construction of Characteristic Tilting Modules

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2002年第1期18卷 129-136页

作者： DENG Bang Ming department of Mathematics. beijing normal university.{2.. P. H. china department of Mathematics Beijing Normal University Beijing P. R. China

Associated with each finite directed quiver Q is a quasi-hereditary algebra. the so-called twisted double of the path algebra kQ. Characteristic tilting modules over this class of quasi-hereditary algebras are constructed. Their endonorphism algebras are explicitly described. It turns out that this class of quasi-hereditary algebras is closed under taking the Ringel dual.

关键词： Quasi-hereditary algebra Characteristic tilting module Ringel dual