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Search Results: 1 - 10 of 335420 matches for " 李宝华 "
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淘洗后的砂金样品要及时烘干

地质与勘探 , 1983,
Abstract: 砂金样品,尤其是砂钻样品,常会有工具铁屑混入.淘洗后的灰砂如不及时晒干或烘干,而直接装入袋内,因潮湿形成铁的氧化物将附在金的表面.小的铁屑、褐铁矿和电磁性矿物有时还粘在金的颗粒上.当用磁选分离样品时,金便进入电磁性甚至强磁性部分中,从而降低了金的品位.这种现象在南方尤其严重.据湖南某地5000个见金样品的统计,电磁性部分见金1146个,占22.92%;强磁性部分见金853个,占17.06%.我们对古龙干河砂金矿品位大于0.05g/m~3的174个钻孔共2389个样品的电磁性部分,用1∶1盐酸进行溶解处理.见金的有121个钻孔,占69.54%,品位平均相对误差4.05%.其中-钻孔基本分析金
数字化声波时差测井曲线逐点判别插值处理法

煤田地质与勘探 , 1994,
Abstract: 用逐点判别插值法对数字化声波时差测井曲线进行处理,以5个测点或9个测点为一组合,逐点判别,剔除非正常点。再根据界面最大时差变化率和曲线形态及非正常点的分布类型对当前非正常时差点进行插值。
JXW—1型微机数字化测井系统在阜新煤田的应用

煤田地质与勘探 , 1992,
Abstract:
二维离散小波提升变换算法的并行结构设计
,
计算机应用 , 2011,
Abstract: ?提出了一种二维离散小波提升变换(2ddwt)的2×2并行结构。该结构充分利用了2ddwt算法固有的行并行、列并行、行列并行的三种并行性,有效提高了算法执行速度,同时显著降低了硬件存储需求。处理n×n图像的时间为n2/4+n/2+1,系统存储需求为3n。fpga实现结果证明了本设计的正确性和有效性。
中蒙干旱半干旱区降水异常的区域性差异及其年代际演变特征
The Spatial Variation in the Normal/Abnormal Precipitation over the Sina-Mongolia Arid/Semiarid Area and Its Decadal Transformation
 [PDF]

万源, 吕世, 董治, 王式功
Advances in Geosciences (AG) , 2012, DOI: 10.12677/ag.2012.21006
Abstract:

本文利用1951~2005年间中蒙干旱半干旱区322个气象测站的月降水量资料,借助聚类和小波等统计分析方法对该区各月降水异常的区域性差异及其年代际演变进行了较为详细的分析,主要揭露了以下事实:1) 同降水量的年变化特征相近,降水空间分布形势也表现出明显的年变化,由春季到夏季,多雨区不断扩展,少雨区不断退缩,直到各地降水量均达到最大,然后由秋季到冬季,少雨区不断扩展,多雨区则不断退缩,直到降水量恢复到全年的最小值,使得1年明显成为降水空间分布变化的一个周期。2) 通过聚类分析给出1951~2005年间各月降水异常的典型空间分布型及其出现的年份和频次,说明不同月份,即使属同一季节,其降水异常的典型空间分布型也有很大差异,不同月份典型空间分布型出现的年份也少有规律可循。3) 中蒙干旱半干旱区降水异常的区域性差异存在着明显的年代际演变。4) 通过小波分析给出一些主要区域逐月降水量年代际变化的主要周期性特征,结果表明同一区域,不同月份,即使属同一季节,其降水量变化的周期和位相也很不同。
Based on the monthly precipitaiton data during 1951 - 2005 for the selected 322 meteorological gauge stations over the Sina-Mongolia arid and semiarid area, the spatial variation in the normal/abnormal precipitation and its decadal transformation for each month have been analyzed in detail utilizing the statistical clustering and the wavelet analysis, disclosing the following facts: 1) Being similar to the monthly precipitation, the spatial distribution of the precipitation is also displaying its argular yearly variation apparently, with the wet area extending continuously and the arid area con-stracting from spring to summer, till the precipitation reaching the maximum at each station, and then, from autumn to winter, the arid area extending and the wet area constracting continuously, till the precipitaiton going back to the minimum at each place, so, one whole year is apparently a circulation of the spatial precipitaiton distribution. 2) The typical spatial distribution patterns of the abnormal monthly precipitation and their appearing years and frequencies during 1951 - 2005 have been found based on the statistical clustering analysis, showing that, the typical spatial distri-bution patterns and their appearing years and frequencies are all largely different from one month to another month even in the same season. 3) There is apparently a decadal transformation in the spatial variation of the normal/abnormal pre-cipitaiton over the Sina-Mongolia arid and semiarid area. 4) The major periods existing in the decadal variation of the precipitation for each calendar month and each major area have been found by the wavelet analysis, disclosing the pe-riodicity and the wave in the precipitaiton variation at some certain place will be different from one month to another even in the same season.

近半个世纪中国北方沙尘暴的空间分布和时间变化规律回顾
Spatial Distribution and Temporal Tendency of the Dust Storm Frequency in North and Northwest China for the Recent Nearly Half a Century
 [PDF]

万元, 董治, 吕世, 王式功, 奥银焕
Climate Change Research Letters (CCRL) , 2012, DOI: 10.12677/ccrl.2012.11001
Abstract: 特别是近10多年来,中外科学家对近半个世纪中国北方沙尘暴的地理分布和时间变化趋势作了大量工作,为了在借鉴前人成果的基础上更进一步把握现在和将来中国北方沙尘暴的发生、发展规律,本文就相关成果进行了详细的回顾、分析和总结:首先在气候意义上进一步阐明了我国沙尘暴发生频数、沙尘源区、爆发路径、传输路径、沉降区域等的地理分布状况及其形成的地表、气候和大气环流成因;然后总结了半个世纪以来我国沙尘暴的年际和年代际变化特征及其区域性差异,并就荒漠化、气候变化及环流演变三方面给出其可能的形成原因;最后提出几点沙尘暴预测和防治的建议。
A lot of efforts have been done on the geographic distribution and temporal variation trend of the dust storm frequency in North and Northwest China during the last half century, especially since 10 or so years before. In order to further understand the occurrence and development regulations for dust storms in China in the near and far future based on the previous successes, this paper has aimed to review, analyze and summarize in detail those relevant achievements obtained by inland and abroad scientists. Firstly, the climatic geographical distributions of the happening frequency, sand and dust sources, outbreak way, transport route and deposition areas of dust storms in China have been further elu-cidated with their causes such as surface conditions, climatic factors and atmospheric circulations. Secondly, the yearly and decadal variation characteristics of the dust storm frequency in China and their differences from area to area have been summarized for the last half century or so, focusing on the desertification land, climate change and atmospheric circulation modification in North and Northwest China to explain all the involved phenomena; Finally, some sugges-tions have been given on the prediction and restriction of dust storm in China.
角膜、眼底反光同时摄影法检测青少年儿童屈光不正的研究
续美如,
中国公共卫生 , 1991,
Abstract: ?本文对66例近视性、67例远视性屈光不正的儿童青少年在散瞳检影验光的同时作角膜眼底反光同时摄影。结果表明:这两种方法诊断屈光不正是高度正相关(近视组r=0.86P<0.0005;远视组r=0.83p<0.0005),这一新方法在诊断屈光不正时有很高灵敏度。该方法的优点还有:操作简便易学、节省时间,本文认为它可用以青少年群体屈光不正的普查。
LnP_5O_(14)晶体的光性特征
,常丽
硅酸盐学报 , 1988,
Abstract:
激光腔外的脉冲压缩
,
物理 , 1993,
Abstract: ?综述激光谐振腔外脉冲压缩技术的基本原理和实验进展,指出国内深入开展此项研究的前提和关键是研制合适的国产光源,最后介绍此技术的现实的和潜在的应用.
怎样才能有效地观察光孤子
,
物理 , 1993,
Abstract: ?到目前为止,国内仍没有成功地令人信服地观察和记录光孤子,要完成这一突破还需作艰苦的努力.该文论述了光孤子存在的物理条件,指出了国内为成功观察光孤子而开展的基础研究和应用研究的方向.
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