Oracle高可用环境下地震业务数据集中管理探索     

丁睿  秦浩文 《地震地磁观测与研究》2011,32(2):75-80

通过前兆数据库迁移到核心数据库,初步探索在Oracle高可用环境下地震业务数据集中管理的优越性.对下一步地震业务数据迁移、整合,核心数据库的性能要求、容灾备份和安全性进行思考.  相似文献   

Inter-Regional Comparisons on the Quaternary Large Mammalian Faunas between China and Sub-Saharan Africa     

TONG Haowen  HU Nan  LIU Jinyi  Ronald CLARKE 《《地质学报》英文版》2011,85(1):91-106

The current and dominant theory about the origin of modern humans is the out-of-Africa hypothesis, which asserts that populations of Homo sapiens left Africa 100,000 years ago and replaced indigenous populations of humans in Eurasia. Many scholars equated the out-of-Africa dispersal of humans with paleoenvironmental changes. However, until now, few have paid special attention to the faunal data and whether or not faunal patterns are supportive of the popular theory. Recent comparative study of the Chinese fauna shows that the communication of faunas between Africa and East Asia could have occurred during the Neogene, but it was very limited during the Pleistocene. In the Chinese Quaternary fauna, only 16% of the genera are also present in the sub-Saharan African fauna. There is also no element among the dominant taxa of the Chinese Quaternary fauna which can be related to the African fauna. There is no reliable proof for the existence of Hippopotamus and Giraffa, as well as Panthera leo, during the Quaternary in China. Two controversial taxa are Acinonyx and Crocuta, about which there is still argument concerning their species identification in Eurasia. It is possible that both of the genera have co-specific taxa in Africa and Eurasia. Although the two genera are confined to Africa today, they did have a long evolutionary history in China. For the Out of Africa hypothesis for Homo sapiens, the implications of the limited faunal interchanges between China and Africa are not completely clear yet.  相似文献   

河北阳原泥河湾盆地山神庙咀早更新世哺乳动物群的发现   总被引：1，自引：1，他引：0       下载免费PDF全文

同号文  胡楠  韩非 《第四纪研究》2011,31(4):643-653

2006～2008年,在泥河湾盆地山神庙咀化石点发现大量保存完好的哺乳动物化石,已初步鉴定出如下种类:兔科(属、种未定)、鼠兔(未定种)、直隶狼、猫科(属种未定)、硕鬣狗(未定种)、草原猛犸象、披毛犀、板齿犀(未定种)、长鼻三趾马(未定种)、三门马、猪(未定种)、真枝角鹿(未定种)、转角羚羊(未定种)及中国羚羊等;尽管...  相似文献   

Douglas-Peucker算法全自动化的多尺度空间相似关系方法     

王荣  闫浩文  禄小敏 《地球信息科学学报》2021,23(10):1767-1777

地图综合本质上是空间相似变换,研究Douglas-Peucker算法及其参数的设置,实质是研究算法的最佳距离阈值与尺度变化间的定量关系,但目前二者关系未知,导致参数设置及化简结果的选择主观性强。为此,提出以多尺度线要素空间相似关系为契合点,利用阈值参数寻优原理确定二者间定量关系,以实现基于DP算法线要素的全自动化简。结果表明：① 二次函数是描述最佳距离阈值与尺度变化间定量关系的最优函数;② 针对来源于相同地理特征区,如长江下游平原,的线要素可行,利用同一最佳距离阈值可实现基于DP算法线要素的全自动化简,且化简结果与已有成果数据吻合度较高;而来源于不同地理特征区域,如长江下游平原和江淮平原,的线要素,用同一最佳距离阈值化简是不合理。因此,应选择不同的最佳距离阈值,以实现不同地理特征区域线要素的DP算法全自动化简。  相似文献   

FloatingEscherichia coli by Expressing Cyanobacterial Gas Vesicle Genes     

WANG Tianhe  KANG Li  LI Jiaheng  WU Wenjie  ZHANG Peiran  GONG Minghao  LAI Weihong  ZHANG Chunyan  CHANG Lei  PENG Yong  YANG Zhongzhou  LI Lian  BAO Yingying  XU Haowen  ZHANG Xiaohua  SUI Zhenghong  YANG Guanpin  WANG Xianghong 《中国海洋大学学报(英文版)》2015,(1):84-88

Gas vesicles are hollow, air-filled polyprotein structures that provide the buoyancy to cells. They are found in a variety of prokaryotes. In this study, we isolated a partial gas vesicle protein gene cluster containing gvp A and gvp C20Ψ from Planktothrix rubescens, and inserted it into an expression vector and expressed it in E. coli. The gas vesicle was developed in bacterial cells, which made bacterial cells to float on medium surface. We also amplified gvp A and gvp C20Ψ separately and synthesized an artificial operon by fusing these two genes with the standardized gene expression controlling elements of E. coli. The artificial operon was expressed in E. coli, forming gas vesicles and floating bacteria cells. Our findings verified that the whole set of genes and the overall structure of gas vesicle gene cluster are not necessary for developing gas vesicles in bacteria cells. Two genes, gvp A and gvp C20Ψ, of the gas vesicle gene cluster are sufficient for synthesizing an artificial operon that can develop gas vesicles in bacteria cells. Our findings provided a wide range of applications including easing the harvest of cultured microalgae and bacteria, as well as enriching and remediating aquatic pollutants by constructing gas vesicles in their cells.  相似文献   

面向地图综合的道路网相似度计算模型     

褚天舒  闫浩文  禄小敏 《测绘科学》2022,47(1):181-187

针对地图制图综合过程中道路网相似度的定量计算问题,提出了一种顾及道路网综合过程的相似度计算模型.方法 基于空间相似关系理论较好地顾及了地图综合中空间关系的相似性;利用语义权重计算总体相似度更加符合地图综合的规则.最终经由430个样本的心理认知实验结果与专业人员的心理认知结果基本一致.实验结果表明:该模型基本符合人类直观...  相似文献   

西菲律宾海末次冰期以来的浊流沉积及其古环境意义   总被引：3，自引：2，他引：1       下载免费PDF全文

党皓文  翦知湣  Franck Bassinot 《第四纪研究》2009,29(6):1078-1085

菲律宾海西部吕宋岛岸外MD98－2188钻孔揭示末次冰期以来发生过数次浊流沉积事件。研究发现浊流沉积层具有密度高、颜色亮度大等物理特征,含有较多粗沉积组分和翼足类化石碎片,说明其来源于浅海沉积物。本文运用AMS 14C测年和浮游有孔虫氧同位素建立精细的年龄模式,发现浊流沉积层段主要与末次盛冰期、冰期Heinrich变冷事件以及氧同位素4期等低海平面时期相对应,推测与千年尺度北半球气候冷期相关的海平面快速上升可能是西菲律宾海浊流沉积的触发原因。这对于认识快速气候变化的环境后果和开展西菲律宾海晚第四纪地层划分对比都有重要意义。  相似文献   

土地利用数据库综合中图斑拓扑关系的创建和一致性维护   总被引：5，自引：0，他引：5  

陈先伟  郭仁忠  闫浩文 《武汉大学学报(信息科学版)》2005,30(4):370-373

以LANDUSE-DAT文件为例，论述了土地利用地图综合中图斑多边形拓扑关系的特点、数据结构定义及生成方法，阐述了土地数据库综合过程中图斑拓扑关系一致性的维护方法。  相似文献   

上海地震台阵的标定方法   总被引：1，自引：0，他引：1  

佟玉霞  秦浩文  任隽 《地震地磁观测与研究》2002,23(2):76-79

地震台阵标定可以校正视慢度和后方位角，从而进一步校正震源位置，有助于提高地震定位精度及地震类型鉴别研究等。此外，台阵标定也可校正由于台阵接收系统而导致视慢度和后方位角的偏差。  相似文献   

抗高程平移和裁剪的格网DEM盲水印算法     

魏征  闫浩文  张黎明 《测绘科学》2016,41(8):170-173,100

针对DEM数据水印常见的攻击方式——高程平移和裁剪,该文提出了一种可有效抵抗攻击的格网DEM盲水印算法。该算法考虑了DEM数据的特点,对原始水印进行扩频处理,使其与高程差值形成映射关系;利用相邻格网的高程差值在高程平移攻击中的不变特性,以量化方式将扩频后水印按位嵌入到高程差值中,将扩张的差值分摊到相邻高程的后一位。实验结果表明,该水印算法具有良好的不可见性,对DEM数据精度影响较小,并且对抵抗高程平移和裁剪攻击具有良好的鲁棒性。  相似文献