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321.
The planktonic foraminiferal faunal census of core MD 05-2894 (7°2.25′N, 111°33.11′E, water depth 1982 m), retrieved from the southern South China Sea (SCS) during the "Marco Polo" cruise in 2005, was performed to investigate the abundance changes of a subsurface dweller, Pulleniatina obliquiloculata. The results display that the abundance of P. obliquiloculata nearly declines to zero during 16.0--14.9 ka, corresponding to the Heinrich 1 (H1) cold interval. The unexpected decrease of P. obliquiloculata occurs in the adjacent cores, roughly between 17 and 14.8 ka based on the previous studies. Accordingly, the Pulleniatina Minimum Event in the last deglaciation can serve as a good stratigraphical indicator, at least in the southern SCS. To further explore the changes of sea surface temperature (SST) and subsurface seawater temperature (SSST), we made parallel Mg/Ca measurements on surface dweller Globigerinoides tuber and subsurface dweller P. obliquiloculata tests. Since the last deglaciation, the SSTs show a continuous increasing trend towards the late Holocene, while the warming of the subsurface water is punctuated by a 2℃-cooling interval across the deglacial Pulleniatina Minimum Event. Both increased 5180 differences between G. ruber and P. obliquiloculata, and increased temperature differences between surface and subsurface water suggest a shoaling of the mixed layer during the deglacial Pulleniatina Minimum Event. Therefore, we consider that the significant changes in the upper ocean structure are responsible for the Pulleniatina Minimum Event during the last deglaciation in the southern SCS. 相似文献
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323.
An Yan GuoHui Ding ZhenFeng Zhou Hui Dong YaKun Zhang Lei Zhu YunGang He GuoQing Zhang YiXue Li Bing Sun Zhong Huang Ke Lan Li Jin HongYan Wang XiaoNing Wang Zhong Yang Yang Zhong JianXin Dai YaJun Guo Hao Wang XiaoYan Che Fan Wu ZhenGan Yuan Xi Zhang ZhiWei Cao XiaoNong Zhou JiaHai Zhou ZhiYong Ma GuangZhi Tong GuoPing Zhao WeiRong Jin Hui Xiong 《科学通报(英文版)》2009,54(13):2164-2167
The outbreak of a novel influenza A (H1N1) virus across the globe poses a threat to human health. It is of paramount importance to develop a rapid, reliable and inexpensive diagnostic procedure. Based on the bioinformatic information from public database, primers specific for influenza A virus surface protein haemagglutinin (HA) of several subtypes (including H1, H2, H3, H5, H7 and H9) were designed. Primer-specific PCR products were subiected to sequencing for accurately distinguishing H1 and H3 subtypes from others. This sequencing-based detection method will not only be applied to rapid detection and simultaneous subtype identification of new influenza A virus H1N1, but also provide the strategies to monitor other new types of influenza virus with explosive potential. 相似文献
324.
对地观测技术发展态势的文献计量分析 总被引:1,自引:0,他引:1
从发表的对地观测科学研究论文和专利文献入手,利用美国Thomson公司开发的Thomson数据分析工具(Thomson DataAnalysis—TDA),分析该研究领域的科研文献和专利文献变化情况,从而对对地观测技术的发展态势进行分析。在ISI Web of Knowledge平台检索SCIE和SSCI网络数据库2002—2007年相关论文共15829篇,对论文的国家和机构分布进行了详细分析,以关键词词频分析了对地观测技术研究的热点,得到微波遥感、定量遥感以及高光谱遥感是近年来的前沿领域,而土地利用和气候变化是应用热点。专利文献分析表明,对地观测专利文献呈现缓慢的增长趋势,全球定位系统专利文献数量较大、增长较快,而遥感、地理信息系统和全球定位系统专利文献分布国家和机构以及关键词词频具有较高的一致性,说明三者结合应用情况显著。 相似文献
325.
文章以官亭高架桥为例,在该桥进行维修加固前,对其进行了合理的检测和评价,得出桥梁的实际状况和承载能力,分析病害、损伤的原因,从而提出有效的维修加固措施.以此桥为例,该文介绍了桥梁的检测方法,检测结果以及加固措施,并对该桥加固前、后静力和动力性能做了对比分析.分析结果表明,加固后的高架桥具有较大刚度和强度,证明粘钢加固设计是合理的,可以继续使用. 相似文献
326.
具有双量子阱结构的一维光子晶体透射谱特性研究 总被引:2,自引:0,他引:2
在适当选择结构参数的基础上,采用传输矩阵法计算模拟一维光子晶体(AB)m(CD)n(AB)m结构模型的透射谱,当光子晶体(CD)n相邻的两个导带分别处于光子晶体(AB)m(AB)m相邻的两个禁带中时,构成一维光子晶体双量子阱结构,在光量子阱透射谱的归一化频率0.3(ωa/2πc)和0.55(ωa/2πc)两处周围,分布着两套具有规律的局域共振峰,出现明显的量子化效应,且两套透过峰数目都可以通过光子晶体(CD)n的重复周期数n来调节,这一现象可以用于设计可调性多通道滤波器。 相似文献
327.
叶桉 《江西科技师范学院学报》2009,(3):1-6,82
中国共产党在赣鄱大地领导开展的民主革命,极大地丰富发展了传统的赣文化。五大革命摇篮的创建,成就了赣文化具有红色神韵的载体;五大原创经典精神的形成。决定了赣文化红色神韵的魂魄。红色赣文化毋庸置疑地成为当代赣文化的核心和主体,其所凝结和体现的政治品牌、教育品牌、思想品牌、道德品牌和形象品牌,又责无旁贷地成为中华民族复兴和江西崛起的强大思想武器和文化力。 相似文献
328.
An easy-to-use site-directed mutagenesis method with a designed restriction site for convenient and reliable mutant screening 下载免费PDF全文
Bao-zhong Zhang Xin Zhang Xiao-ping An Duo-liang Ran Yu-sen Zhou Jun Lu Yi-gang Tong 《浙江大学学报(自然科学英文版)》2009,10(6):479-482
Site-directed mutagenesis (SDM) has been a very important method to probe the function-structure relationship of proteins. In this study, we introduced an easy-to-use, polymerase chain reaction (PCR)-based SDM method for double-stranded plasmid DNA, with a designed restriction site to ensure simple and efficient mutant screening. The DNA sequence to be mutated was first translated into amino acid sequence and then the amino acid sequence was reversely translated into DNA sequence with degenerate codons, resulting in a large number of sequences with silent mutations, which contained various restriction endonuclease (RE) sites. Certain mutated sequence with an appropriate RE site was selected as the target DNA sequence for designing a pair of mutation primers to amplify the full-length plasmid via inverse PCR. The amplified product was 5′-phosphorylated, circularized, and transformed into an Escherichia coli host. The transformants were screened by digesting with the designed RE. This protocol uses only one pair of primers and only one PCR is conducted, without the need for hybridization with hazardous isotope for mutant screening or subcloning step. 相似文献
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330.
基于压缩感知的频谱感知研究多是要重构出原始信号,而重构的精确度却直接影响到频谱检测的效果,为降低由此因素而造成的低检测率以及计算复杂度,提出一种在压缩感知框架下的非重构频谱检测算法,将信道划分为多个小信道,依次感知每个小信道,得出所划分信道组的采样协方差矩阵,再与能量检测算法结合分析最终得到每个小信道中的占用情况。对不同的压缩率、信噪比以及用户数分别进行仿真,仿真的结果表明,当压缩率在30%以上和信噪比在-6 d B以上时检测效果较为理想,且多用户的情况下检测概率更高。相对于重构算法,本算法的检测概率更高,计算复杂度更低,检测时间也更短。 相似文献