检索结果-南通市图书馆

Angular Distribution of Element Contents in Tree Rings and the Environmental Information

在线全文

学校读者我要写书评

暂无评论

Pedosphere 1999年第1期9卷 69-76页

作者： KE SHANZHE LIU ZHENGRONG QIAN JUNLONG CHEN RUSONGI and KE XIAOKANG (Physics department, Nanjing University, Nanjing 210095,china)(Nanjing institute of Geogmphy and Limnology, the Chinese Academy of Sciences, Nanjing 210008, china)(Garded and Greenbelt 南京大学物理系江苏南京 210093 南京大学物理系江苏南京中科院南京地理与湖泊所江苏南京 210008 南京大学化学系江苏南京 210009

Element contents of tree rings and soils near tree roots collected from Deodar cedar (Cedrus deodara (Roxb.) G. Don) and Masson pine (Picks massoniana lamb.) were determined to study the relationship between the angular distribution of element contents in tree rings and the environmental information. The chemical composition and properties of soils are very much complicated, which leads to the non-uniform distribution of the element contents in tree rings. The statistical multi-variable regression method was used to got the information of the tree-centered distribution of element contents in the environment (soil) (C’), C’(z, θj ), from the distribution of element contents in tree rings (C), C(Z, θi), which depends on the plane azimuth angle (θi), i. e., C=C(Z,θi), where Z is the atomic number of the element, with a satisfactory result,though this study is only a primary one.

关键词： angular distribution element contents environmental information tree rings

Research on Application technology Oriented Rapid Response Manufacturing in the Distributed Network Environment

在线全文

学校读者我要写书评

暂无评论

厦门大学学报（自然科学版） 2002年第S1期41卷 43-44页

作者： JIN Ji-wen, NI Yan-rong, XI Jun-tong, FAN Fei-ya, JIN Ye (CIM institute, department of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200030, china)

A new chance of developing traditional manufacturing industry comes forth with the development of network technology. Application technology oriented rapid response manufacturing in the distributed network environments, that is, how to take advantage of the Intranet and Internet, combine the numerous manufacturing resources spread around the region, the country and even the globe is the key to the agile design, manufacturing and the buildup of comprehensively competitive power, at the same time, is also an important research direction in the field of advanced manufacturing technology. Rapid response manufacturing in the distributed network environment is a newly manufactory pattern that can be used to implement the conception of agile design and manufacturing, but there are some new problems coming with it, which will directly influence the enterprise’s ability of rapid response in the distributed network manufacturing pattern and lead to the failure of the league and the lost of the given orders. In this paper, we establish some approaches to solve these problems in product development process. The paper then presents the research on key application technologies and solutions includes: network safety strategy which guarantees data transferring among the leaguer members, production data management based on Web/DOT (Distributed Object technology) and XML criteria which guarantees data exchange in structure-variance characteristic environments, the network platform which provides the conversion service of different types of CAD files each other. All of these solutions are aim for technology problems existing in the distributed network environments and among the league members. Finally, the paper takes one project, that is, the establishment of the online application service system for Shanghai Advance Manufacturing technology Research Center as a good instance.

关键词： distributed network environment rapid response manufacturing data exchange

Multiple Functions of Nuclear DNA Helicase Ⅱ (RNA Helicase A) in Nucleic Acid Metabolism

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第3期36卷 177-183页

作者： Frank GROSSE department of Biochemistry institute of Molecular Biotechnology POB 100 813 D-07708 Jena Germany

Nuclear DNA helicase II (NDH II), or RNA helicase A (RHA), was initially discovered in mammals by conventional protein purification methods. Molecular cloning identified apparent sequence ho- mologies between NDH II and a Drosophila protein named maleless (MLE), the latter being essential for the Drosophila X-chromosome dosage compensation. Increasing amounts of evidence suggest that NDH II is involved in multiple aspects of cellular and viral DNA and RNA metabolism. Moreover the functions of NDH II may have potential clinical implications related to viral infection, autoimmune diseases, or even tumorigenesis.

关键词： DNA and RNA helicase maleless (MLE) X-chromosome dosage compensation dsRBD RGG-box transcription RNA processing RNA transport actin nucleolus SLE (systemic lupus erythematosus) virus

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

数学全息方法及其在数学科研和教学中的应用

数学教育学报 2004年第3期13卷 43-45页

作者：彭拯湖南理工学院数学与应用数学系湖南长沙414006

宇宙全息律作为客观世界的一种普遍规律,被反映到数学这种人们认识世界的基本工具上,形成数学科学的一种普遍规律,即数学全息律.以数学全息元为起点,利用数学全息律进行数学科研与教学的方法就是数学全息方法.利用周期研究时间函数和利... 详细信息

宇宙全息律作为客观世界的一种普遍规律,被反映到数学这种人们认识世界的基本工具上,形成数学科学的一种普遍规律,即数学全息律.以数学全息元为起点,利用数学全息律进行数学科研与教学的方法就是数学全息方法.利用周期研究时间函数和利用“生成元”研究数学结构等均是应用数学全息方法的生动事例;同时,数学全息方法还是促进数学创造的有力工具.数学全息方法在数学教学中也有着广泛的应用.

关键词：数学全息律数学科研数学教学数学创造

THE NUCLEAR MAGNETIC RESONANCES OF CARBAZOLE DERIVATIVES

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 1980年第6期28卷 744-753页

作者：徐广智王玉珍王竹庭沈其丰唐有祺 institute of Chemistry Academia Sinica beijing Research institute of Chemical Industry department of Chemistry Beijing University

In this paper, 1H, 13C nuclear magnetic resonance （NMR） data of 14 carbazolc derivativesand 13C spin-lattice relaxation time of some derivatives are presented. The theoretical 1HNMR spectra of the carbazole ring protons in the 14 derivatives are calculated to matchthe experimental spectra by NMRCAL program. The effects of the carbazole ring on thechemical shifts of the protons and carbons of the R-group are discussed. The substituenteffects of carbazole ring on the α-H, β-H, α-C, β-C and v-C of the R-group are estimated. Itis found the the 1JCH of CH2 bonded to N in the R=--CH2--R’(R’=CnH2n+1),--CH2--O,--CH2--CH2--Br and--CH2--CH=CH2 derivatives are additive and can be expressed by 1JCH=8x+8y+8z,where 8x, 8y and εz are respectively the contributions of substituents x, y and z to 1JCH.

关键词： THE NUCLEAR MAGNETIC RESONANCES OF CARBAZOLE DERIVATIVES than 兀一 ppm

The impacts of '05.6' extreme flood event on riverine carbon fluxes in Xijiang River

在线全文

学校读者我要写书评

暂无评论

The impacts of '05.6' extreme flood event on riverine carbon...

Mining Concept-Centric Phrase Inference Set for Complex Question Paraphrase

中国科学院地质与地球物理研究所2007学术年会

作者： SUN HuiGuo~(1+),HAN JingTai~1,ZHANG ShuRong~2 & LU XiXi~2 1 institute of Geology and Geophysics,Chinese Academy of Sciences,beijing 100029,china 2 department of Geography,National University of Singapore,117570,Singapore

An extreme flood event with a frequency of nearly 200 year occurred in June of 2005 in the Xijiang River, the main trunk stream of the Zhujiang *** were systematically collected during the flood event,and water quality parameters,including total suspended sediment(TSS),dissolved inorganic carbon(DIC),dissolved organic carbon(DOC),and particulate organic carbon(POC) were analyzed, and riverine carbon concentrations associated with its changing pattern through the flood process were *** parameters reflect the changes in basin surface flow and subsurface flow during the *** flood event influenced annual flux estimations of POC,DOC,and DIC to great extents. Based on carbon flux estimations for the year 2005 and the flood event(June 21-28) in the Xijiang River,it was found that DIC,DOC,and POC fluxes during‘05.6’ flood event are 1.52×***.a, 0.24×10 ***,and 0.54×10 ***.a,and account for 14.87%,24.75%and 44.89%of the annual fluxes in 2005,*** results suggested that carbon exports during extreme flood events had great contributions to the total carbon fluxes and composition of various carbon components,being important for accurate estimates of annual carbon fluxes in rivers with frequent floods.

关键词： Xijiang River flood riverine carbon flux

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

Mining Concept-Centric Phrase Inference Set for Complex Ques...

Ultrafast excitation relaxation in light-harvesting complex LH2 from *** 601

第四届全国信息检索与内容安全学术会议

作者： Yan Zhao Xiaolong Wang Yaoyun Zhang Shixi Fan ~1 department of Computer Science and technology,Harbin institute of technology Shenzhen Graduate School,Guangdong Shenzhen 518055,china

Many efforts at various levels from shallow syntactic analysis to deep semantic inference have been made to interpret paraphrase in ***,no attention has yet been paid from the pragmatic *** paper approaches semantic paraphrase in complex questions with a focus on pragmatics:a corpus of question paraphrases is first collected by mining the huge amount of question-answer pairs in on-line discussion groups. Then relevant phrases of restricted domain,such as events,actions,attributes of the same concept,are grouped into inference sets statistically in a domain-independent way,which requires deep-level inference to resolve at *** in a FAQ-style QA(question answering)system of f’mancial domain demonstrate that the extracted concept-centric phrase inference sets improve the system ability to capture complex questions of similar user intentions,with an enhancement of the F1-score by 14.16% and 45.44% at rank 20 over our two baselines.

关键词： Phrase Inference Paraphrase Complex Question Question Answering

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

Science china Chemistry 2004年第3期47卷 192-199页

作者： GUO Lijun1,2, LIU Yuan3, LIU Weimin2, GUO Junhua1, XU Chunhe3 & QIAN Shixiong2 1. School of Physics and Information Optoelectronics, Henan University, Kaifeng 475001, china 2. Physics department, Fudan University, Shanghai 200433, china 3. Shanghai institute of Plant Physiology, Chinese Academy of Sciences, Shanghai 200032, china 1. School of Physics and Information Optoelectronics Henan University 475001 Kaifeng China 2. Physics department Fudan University 200433 Shanghai China 3. Shanghai institute of Plant Physiology Chinese Academy of Sciences 200032 Shanghai China

The energy relaxation and kinetic evolution of transient spectra of bacteriochloro- phylls (BChls) in light-harvesting complex LH2 from Rb. sphaeroides 601 were investigated using femtosecond pump-probe technique. Upon 783 nm excitation, the energy at B800 BChls ex-periences an intramolecular redistribution with 0.35 ps time constant before transferring to B850 BChls. With tuning the excitation wavelength, the dynamical evolution of excited BChls was clearly observed, which indicates an obvious competition between the ground state bleaching and excited state absorption (ESA) of BChls involved and an isosbestic point near 818 nm, and also demonstrates that from the lower electronic excited state of B800 BChls to the higher exci-tonic state of B850 BChls is an efficient routine for energy transfer. The excitation energy in higher excitonic states of B850 BChls relaxes rapidly to the next lowest excitonic state by inter-conversion, delocalization to adjacent molecular, populating the lowest excitonic state and the change of molecular conformation.

关键词： photosynthesis, light-harvesting complex, energy transfer, ultrafast, dynamics, purple bacteria.

在线全文

学校读者我要写书评

暂无评论

脂砚斋是什么人

铜仁学院学报 2011年第6期13卷 37-43页

作者：钟云霄北京大学物理学院技术物理系北京100084

"脂砚斋"是一个红学的"黑洞",不小心掉进去了,就像任何物质掉进黑洞那样,只能在黑洞中转,永远也不能出来了。从曹雪芹手里传出去的《红楼梦》根本没有什么批语,各种批语包括脂批都是后来在流传中加上的。程伟元、高鹗和戚蓼生都没有见过... 详细信息

"脂砚斋"是一个红学的"黑洞",不小心掉进去了,就像任何物质掉进黑洞那样,只能在黑洞中转,永远也不能出来了。从曹雪芹手里传出去的《红楼梦》根本没有什么批语,各种批语包括脂批都是后来在流传中加上的。程伟元、高鹗和戚蓼生都没有见过"脂批本"。脂砚斋作为比较早的一些《红楼梦》爱好者,在一些手抄本上写下评语,有一些触摸到了《红楼梦》的真谛,值得后来人参考。

关键词：脂砚斋脂批流传价值