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141.
梁延玲 《科技情报开发与经济》2010,20(8):27-29
结合图书馆实践分析了高校图书馆存在的一些弊端和问题,从改革的角度对观念的转变进行了探讨,对高校图书馆改革的发展提出了具体的建议。 相似文献
142.
以基础地理数据为例,在研究现实世界-计算机世界-数据库中事件-变更操作-要素之间的逻辑关系的基础上,通过建立要素信息表、事件信息表以及包含事件关联、事件约束的事件树索引体系,提出并实现了面向事件的地理要素的时空回溯方法,为地理要素的时空查询与回溯奠定了基础. 相似文献
143.
为解决交通拥堵问题, 设计并实现了一套具有实时、便捷、低成本、高精度、低误差的智能交通系统(ITS: Intelligent Transport System)。该系统由道路上架设的摄像头采集实时交通图像为主要研究对象, 在嵌入式Linux 系统下, 采用开源计算机视觉库(OpenCV)对车辆变道的行为信息进行统计计算, 并将完整程序移植到ARM11 微处理器上实现该算法。实验结果表明, 该系统的实时性好、统计结果准确; 系统工作稳定, 数据传输准确, 有效地避免了外界干扰, 具有较强的实用性。 相似文献
144.
叶燮的《原诗》针对当时文坛的复古主义思潮和追求偏僻怪戾的形式主义倾向.提出了以“变”为核心,以“因创”“正变”“源流”的艺术辩证观为内容,以“温柔敦厚”的儒家诗教为指归的理性主义诗学观。 相似文献
145.
最小Higgs模型(LH模型)中由于镜像轻子和标准模型(SM)轻子之间存在味改变耦合,会对τ+μ-Z(γ)顶角产生单圈贡献,从而使e~+e~-→τ~+μ~-过程的截面增加,这一效应能被实验探测到.利用LH模型研究了e~+e~-→τ~+μ~-过程,在Mathematica 7.0中通过调用High Energy Physics和Loop Tools,经过复杂计算得到其截面σ.通过这类过程探讨LH模型的效应. 相似文献
146.
本文合成了铕-联吡啶的二元配合物Eu(bpy)2(NO3)3(H2O)2,用元素分析、红外及紫外光谱对配合物进行了表征.采用循环伏安法,研究了用Nafion将Eu(bpy)2(NO3)3(H2O)2修饰于金电极上的电化学发光行为.讨论了介质、pH对该体系电化学发光性质的影响,推测了Eu(bpy)2(NO3)3(H2O)2电化学发光的机理.结果表明:在没有共反应试剂存在的条件下,Eu(bpy)2(NO3)3(H2O)2在pH 8.0的硼砂缓冲溶液中可以产生较强的电化学发光,其发光体可能为Eu*(bpy)2(NO3)3(H2O)2. 相似文献
147.
Wang LiBo Yang ZuoSheng ZHang RongPing Fan DeJiang Zhao MeiXun Hu BangQi 《科学通报(英文版)》2011,56(15):1588-1595
Sea surface temperature (SST) records in the South Yellow Sea during the last 6200 years are reconstructed by the unsaturation index of long-chain alkenones (K 37 U ’) in sediment core ZY2 from the central mud area.The SST records varied between 14.1 and 16.5°C (15.6°C on average),with 3 phases:(1) A high SST phase at 6.2-5.9 cal ka BP;(2) A low and intensely fluctuating SST phase at 5.9-2.3 cal ka BP;and (3) A high and stable SST phase since 2.3 cal ka BP.Variation of the SST records is similar to intensity of the Kuroshio Current (KC),and corresponds well in time to global cold climate events.However,the amplitude of the SST response to cooling events was significantly different in different phases.The SST response to global cooling event was weak while the KC was strong;and the SST response was strong while the KC was weak.The difference in amplitude of the SST response is possibly caused by the modulation effect of the Yellow Sea Warm Current which acts as a shelf branch of the KC and a compensating current induced by the East Asia winter monsoon.The warm waters brought by the Yellow Sea Warm Current cushion the SST decrease induced by climate cooling,and both the Kuroshio and East Asian winter monsoon play important roles in the modulation mechanism.The SST records display a periodicity of 1482 years.The same period was found in the KC records,indicating that variation of the SST records in the central South Yellow Sea is strongly affected by KC intensity.The same period was also found in Greenland ice cores and North Atlantic and Arabian Sea sediment cores,showing a regional response of marine environmental variability in the East China Seas to that in the global oceans. 相似文献
148.
A method is introduced in this paper to study the effect of future climatic change on the economy. The researchers determine
the economic output of climate change from historical data, and provide a method to quantitatively predict economic output
of climate change by an economic-climatic model. A historical reciprocating examination is used to analyze output data for
various crops in eight agricultural areas in China and meteorological data from 160 observatories in China from 1980 to 2000.
The results show that the methods used are reasonable to a certain extent and good in application. 相似文献
149.
XinMiao Lü LiPing Zhu Mitsugu Nishimura Yoshimune Morita Takahiro Watanabe Toshio Nakamura Yong Wang 《科学通报(英文版)》2011,56(27):2931-2940
A 380-cm-long sediment core was acquired from the deep water area of Pumoyum Co, southern Tibet. Twenty-five plant residue
samples were selected, and organic carbon stable isotopes were obtained using the AMS 14C chronological method. The 14C age and carbon reservoir effect were calibrated with surface sedimentation rate measurements using 210Pb dating. Results showed that the core sediment deposited over 19 cal ka BP. Based on a multi-proxy analysis of TOC and IC
contents, grain size and pollen assemblage data, the palaeoclimatic evolution of Pumoyum Co was reconstructed since the last
glacial. Pumoyum Co was a shallow lake prior to 16.2 cal ka BP; although the glacier around the lake began to melt due to
increasing temperatures, climate was still cold and dry. In the interval of 16.2–11.8 cal ka BP, the sedimentary environment
fluctuated drastically and frequently. Two cold-events occurred at 14.2 and 11.8 cal ka BP, and these may correspond to the
Older Dryas and the Younger Dryas events, respectively. After 11.8 cal ka BP, Pumoyun Co developed into the deep lake as it
is now. The lake water temperature was relatively lower at that time because of influx of cold water from glacial meltwater
entering the lake. As a result, the multi-proxy indicators showed no sign of warm conditions. Comparisons between the sedimentary
record of Pumoyum Co with that of other lakes of the same age in southern Tibet indicate a warmer climate following the last
deglaciation influenced the southeastern Tibetan Plateau. These results imply that the southwest Asian monsoon gradually became
stronger since the deglaciation during its expansion to the inner plateau. The glacial-supplied water of the lake responded
sensitively to cold-events. The entire southern Tibet region was dominantly influenced climatically by the southwest Asian
monsoon during the Holocene. 相似文献
150.
为了探讨气候变化背景下温室气体排放权分摊机制这一研究难点,综述了温室气体减排责任分解方法的研究现状,遵循"共同但有区别的责任"思想并利用WRE稳定性廓线和IEA/SMP交通模型,开发了SMP-WRE模型。应用该模型建立了一种产业部门具体减排责任的分解方法,并以中国轻型车部门为例,展示了该方法的实现过程。结果表明:全球轻型车的基准排放是目标排放的2~4倍,说明轻型车部门实现450×10-6和550×10-6的CO2稳定水平难度很大。目标分解后的地区排放变化率欧美国家较小、中国较大,原因是欧美汽车市场规模饱和,而中国汽车正爆发式增加,排放增加不可避免。 相似文献