检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

美国女性主义文化研究述评

山西大学学报(哲学社会科学版) 2004年第4期27卷 91-95页

作者：张舍茹北京印刷学院外语系北京102600

女权主义在欧美作为一种思想活动和一种政治策略已经有了一段很长的历史。虽然女性主义一开始就不是传统意义上的独立学科,因为它既在现存学科之中,又在现存学科之外,曾一度被称为是只有观点,没有理论和方法的非学术政治。如今,在文化... 详细信息

女权主义在欧美作为一种思想活动和一种政治策略已经有了一段很长的历史。虽然女性主义一开始就不是传统意义上的独立学科,因为它既在现存学科之中,又在现存学科之外,曾一度被称为是只有观点,没有理论和方法的非学术政治。如今,在文化研究和文化社会学的领域,人们对大众文化中的女性形象表现出与日俱增的兴趣,使之成为广泛复苏的女权主义和女权主义理论的组成部分。美国女性主义文化研究在这方面提供了有力证明。

关键词：女性主义女性形象文化研究大众文化大众媒介

Evolution of Apatites in the Diagenesis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1990年第2期64卷 147-162,233+236页

作者： Liu Kuiwu institute of Geology, Academia Sinica, beijing Liu Linqun Chinese Academy of Geological Sciences Beijing

Apatites occurring in sedimentary rocks are carbonate fluorapatites (C-F apatites) with differentco_2 contents. During diagenesis. the co_2 in the C-F apatites gradually decreased with the increasing strengthof diagenesis. resulting in the systematic changes in refractive index. specific gravity, cell parameters and crystalchemistry of apatites. On the basis of X-ray diffraction and IR spectroscopic analyses, the author proposes twoparameters for determining diagenetic stages. i.e.. the crystallinity index (CR) and sharpness index (SH). Thesetwo parameters serve as new criteria for the determination. which due to the common existence of phosphorousnodules and bands and argillo-crystalline cement in sedimentary rocks, most likely have wide prospects for ap-plication.

关键词： Evolution of Apatites in the Diagenesis

Wind vector retrieval using dual polarization imagery of ASAR

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第11期16卷 1183-1187页

作者： SONG Guiting~ 1,2 , HOU Yijun~1** and QI Peng~1(1. institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, china 2. Graduate School, Chinese Academy of Sciences, beijing 100039, china) institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Graduate School Chinese Academy of Sciences Beijing 100039 China

A new algorithm for retrieving wind vector using dual polarization imagery of advanced synthetic aperture radar (ASAR) is developed and tested. Based on the combination of co-polarization and cross-polarization, this new algorithm effectively eliminates the 180° ambiguity which occurs when using single imagery of the ASAR to retrieve wind vector. This algorithm also solves the problem that the retrieval results will break down on very small spatial scales. The results retrieved from dual polarization imagery of ASAR show that the wind speed and direction are in agreement with the data from Quikscat and buoy measurements. The root mean square errors of wind direction and speed between the retrieved results and data from Quikscat are 2.21° and 0.53 m/s, respectively. comparisons between the new method and the traditional method show that the new methods fit the buoy data and Quikscat data a little better than the traditional method in this image.

关键词： wind vector retrieval ASAR dual polarization.

Improvement of a 3D radar backscattering model using matrix-doubling method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第7期53卷 1029-1035页

作者： NI WenJian1,2, GUO ZhiFeng1 & SUN GuoQing3 1 State Key Laboratory of Remote Sensing Science, jointly sponsored by the institute of Remote Sensing Applications of Chinese Academy of Sciences and beijing Normal University, beijing 100101, china 2 Graduate University of Chinese Academy of Sciences, beijing 100049, china 3 Department of Geography, University of Maryland, college Park, MD 27042, USA State Key Laboratory of Remote Sensing Science jointly sponsored by the 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 Department of Geography University of Maryland College Park USA

Radiative transfer models have been widely used to simulate the radar backscattering from forested areas. A three-dimensional radar backscatter model of forest canopy developed in previous studies takes full account of spatial position of trees in a forest stand, and the interactions among crown, trunk and ground surface. The model predicted well for the co-polarized backscatter measurements, but underestimated the backscattering for cross-polarization, primarily because only the first-order scattering within tree crowns was considered in the model. The backscattering at cross-polarization depends strongly on multiple scatter- ing within tree crowns. To produce good estimations for cross-polarized component, the matrix-doubling method is employed here to compute multiple-scattering within the crown. The modified model is compared with the original model, and the field forest measurements and AIRSAR data are used for validation of the modified model. The cross-polarization backscattering is improved in different degrees for different crown structures and at different bands.

关键词： remote sensing forestry electromagnetic propagation radar backscattering model matrix-doubling

Alkaline diagenesis and its genetic mechanism in the Triassic coal measure strata in the Western Sichuan Foreland Basin,china

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2009年第4期6卷 354-365页

作者： Jiang Zaixing Qiu Longwei Chen Guiju college of Energy China University of GeosciencesBeijing 100083China college of Earth Resources and Information China University of PetroleumShandong 257062China Sinopec Exploration and Production Research institute Beijing 100083China

The reservoir of the upper Triassic Xujiahe Formation (T3x) in the Western Sichuan Foreland Basin is a set of terrigenous clastic rocks in an environment of coal measure sediments. Diagenesis greatly controls the physical properties of the reservoir through different responses of minerals to acidic and alkaline diagenetic environment. The dissolution of unstable components such as feldspar, rock fragments, carbonate cement, and clay minerals is the major source of secondary pores under acidic diagenesis, while the dissolution of quartz increases the reservoir space in the fault-fold zone of Longmen Mountain and Leikoupo paleo-hills. The dissolution of quartz is a result of cross-formation flow of fluid in the Himalaya epoch and the invasion of alkaline formation water from the Triassic Leikoupo and Jialingjiang formations through fault and fracture systems. In the vertical succession, acidic dissolution occurs at a shallow depth of less than 2,180 m, and alkaline dissolution occurs at a greater depth of more than 2,280 m. The reservoir space is formed by the influence of both acidic and alkaline dissolution in the depth interval of 2,180–2,280 m.

关键词： Sichuan Basin upper Triassic alkaline diagenesis porosity genetic mechanism

Theoretical study on the reaction mechanism of(CH_3)_3co+co

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2005年第1期48卷 18-24页

作者： ZHAO Hongmei1,2,3, SUN Chengke1,4, ZHANG Rongchang3, XI Hongmin3 & LI Zonghe1 1. Department of Chemistry, beijing Normal University, beijing 100875, china 2. The Laboratory of Molecular Reaction Dynamics, institute of Chemistry, Chinese Academy of Sciences, beijing 100080, china 3. Department of Chemistry, Beihua University, Jilin 132013, china 4. Department of Chemistry, Qujing Normal University, Yunnan 655000, china Department of Chemistry Beijing Normal University Beijing China The Laboratory of Molecular Reaction Dynamics Institute of Chemistry Chinese Academy of Sciences Beijing China Department of Chemistry Beihua University Jilin China Department of Chemistry Qujing Normal University Yunnan China

The reaction mechanism of (CH3)3co with co has been theoretically investigated using density-functional theory (DFT) calculations at B3LYP/6-31G* level. In order to get more reliable energy values the single-point energy is evaluated at CCSD (T)/6-31++G** level. The results show that the reaction is multi-channel and the reaction of (CH3)3co radical with co mostly produces (CH3)3C + co2. The reaction could play a role in eliminating air pollution.

关键词： DFT, B3LYP, (CH3)3co, radical.

RESEARCH ON TESTING METHOD OF DYNAMIC STRAIN ON THE WALLBOARD OF PRINTING PRESS

在线全文

学校读者我要写书评

暂无评论

RESEARCH ON TESTING METHOD OF DYNAMIC STRAIN ON THE WALLBOAR...

SYNTHESIS AND PROPERTIES OF ANILING ANILING AND 0-AMINOBENZENESULFONIC ACID coPOLYMER

2006年中国机械工程学会年会暨中国工程院机械与运载工...

作者： ZHAO Jibin, WANG Yiming, WU Shuqin Dept. of Mechanical Eng., beijing institute of graphic co.munication, beijing 102600, china

The load distribution on the wallboard is the basis of structure optimization of the wallboard of printing press. A testing method of dynamic strain on the wallboard of printing press is presented. By

关键词： Printing press dynamic testing strain wallboard.

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

Chinese Journal of Polymer Science 1999年第2期17卷 165-170页

作者： Jun-hua Fan Mei-xiang Wan Dao-ben Zhu institute of Chemistry, Chinese Academy of Sciences, beijing 100080, china institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

Poly(aniline- co-o-aminobenzenesulfonic acid) (PAOABSA) as a water soluble conducting polymerwas synthesized by chemical polymerization. The productivity and the room-temperature conductivity of thecopolymer were measured as a function of the reaction conditions, such as reaction temperature, the ratio ofoxidant to monomer and the degree of sulfonation defined as the ratio of sulfur to nitrogen atoms(S/N). Themain results obtained are summarized as follows : (1) lower reaction temperature (at about 0℃) is favorablefor the enhancement of the room-temperature conductivity of the copolymer; (2) higher content of oxidant isunfavorable for increasing the room-temperature conductivity of the copolymer; (3) both productivity androom-temperature conductivity of the copolymer decrease with increase of the degree of sulfonation whichwas always lower than 0.5 even an excess of o-aminobenzenesulfonic acid was added, probably because thereactivity ratio of aniline (γ=2.99± 0.05) is much higher than that of o-aminobenzenesulfonic acid (γ_2 = 0.06±0.02) estimated by using Fineman-Ross method and least square method.

关键词： Watersoluble polyaniline Reactivity ratio copolymer

低信噪比下的Turbo编译码算法研究及性能评估

在线全文

学校读者我要写书评

暂无评论

铁道学报 2004年第2期26卷 66-71页

作者：黄和斌肖扬北京莘夏科技开发有限责任公司北京100011 北京交通大学信息科学研究所北京100044

由于Turbo码优异的纠错性能,CDMA2000与WCDMA将其作为候选的信道编码方案。本文研究了Turbo码的基本原理和编解码算法,在此基础上对Turbo码编解码系统进行了计算机仿真。本文设计的Turbo码编解码采用了伪随机交织器,它将低重量输入信息... 详细信息

由于Turbo码优异的纠错性能,CDMA2000与WCDMA将其作为候选的信道编码方案。本文研究了Turbo码的基本原理和编解码算法,在此基础上对Turbo码编解码系统进行了计算机仿真。本文设计的Turbo码编解码采用了伪随机交织器,它将低重量输入信息序列产生低重量编码序列的关系打破,提高了Turbo码编解码系统性能。系统仿真结果及分析表明有译码迭代次数、RSC分量码,交织器大小与交织器图等几个因素会影响Turbo码编解码系统性能。

关键词：无线通信 Turbo码 LOG-MAP算法迭代译码