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951.
ICP发射光谱法测定矿样中痕量稀土分量本文讨论了以ICP-AES法测定矿样中痕量稀土元素分量方法.实验曾借鉴岩矿测试所的方法.此方法是将试样经阳离子交换富集,浓缩至小体积,加入内标后,通过气动雾化器将溶液输送到ICP激发,摄取光谱.不同稀土元素的检出限分别为0.00X~0.Xμg/g各被测元素光谱测定相对标准偏差为1.8~4.1%.经GSD-1~GSD-8标样三次分析,以及经半年多来五批样品的生产实践证明,本方法流程简单,分析速度快,易于推广,检出限和精确度基本上能满足需要.  相似文献   
952.
Along with the booming of dendrochronology in China, the woody species for the tree-ring study have expanded gradually from tree species to the shrub and dwarf shrub species in the last decades. The zonal woody species in the vast alpine mountains, arid desert areas and arid regions in China are mostly shrubs and semi-shrubs, which is very important to understand the process of regional evolution, environmental protection and ecological recovery. In this paper, the shrub species which have been studied on tree rings in cold and arid areas of China were collected and sorted, and the fundamental research advances were presented, which include the shrub tree ring identification, radial growth characteristics, and chronology construction by different parameters. The applications of shrub dendrochronology to the subjects in eco-response, paleoclimate reconstruction, hydrological process, ecological study of artificial forest and ecological restoration were also presented. The prospect of shrub dendrochronology in the future was also discussed.  相似文献   
953.
By utilizing the denser upper-air observations from the Okinawa region and Japanese islands during August 17-23, 1975, the vertical transports of heat and moisture by cumulus convection in the typhoon No. 7507 have been calculated. It is found that there exist a large apparent heat source (Q1) and a mois-ture sink (Q2) in the southern part of the typhoon at the disturbance, growing and mature stages. The magnitudes of the apparent heat source and moisture sink ace rather small, or turn into the apparent heat sink in the northern sector of the typhoon. In the southern part of the typhoon, the total cloud mass flux (Mc) is positive, whereas in the northern part of the typhoon Mc is negative. The above-mentioned distributions of Q1, Q2 and Mc agree well with the major cloud patterns.In the southern part of the typhoon, Q2 is positive because the drying effect is always larger than the evaporative cooling, whereas in the northern part of the typhoon, the opposite case is true because both the drying and evaporating effects of liquid water make a negative contribution to Q2.  相似文献   
954.
文中之羟钒锌铅矿系国内首次发现,用化学分析、X射线法、差热、红外光谱等手段进行了研究。 矿物呈黄褐色完美的晶簇,比重6.14,成分、结构及物理性质和国外同类矿物相同。作者重点地研究了它的热相变全过程,进而指出这是一种和多金属硫化矿床有关的次生矿物。  相似文献   
955.
Having investigated the loess-paleosol sequence in various loess deposition basins in the China Loess Plateau, authors have found that the paleosol complex S5 is of special significance in terms of Pleistocene paleoclimate. Paleopedological, micromorphological, palynological and paleomagnetic evidences indicate that this paleosol complex formed in the interval of 460,000 to at least 560,000 years BP, which was a climatic optimum.  相似文献   
956.
The normal typhoon paths with 109 cases during the period from 1960 to 1979 have been analysed in this study.These paths are divided into 7 categories.The effect of the position and intensity of largescale wave on each category has been examined.It has been discovered,as a result,that this effect is rather evident.On the other hand,the teleconnection between different centers of anion does exist.A simple theoretical analysis indicates that the teleconnection is related to the propagation of wave energy.Thus,to predict comectly typhoon path,not only the steering flow of typhoon,but also,more significantly,the behavior of large-scale wave over the Northern Hemisphere must be taken into consideration.  相似文献   
957.
本文用单轴压缩下砂岩试件的P、s波超声实验,对含裂隙高空度砂岩破裂前的Vp、Vs、Vp/Vs、Ap、As、As/Ap,初动段频谱,介质传递函数作了一系列实验研究。结果表明:l.Vp、Vs及Vp/Vs的变化同花岗岩,2.As/Ap要发生变化,3.有低频增加现象,4.介质传递函数发生变化,5.有第二P波产生。最后文章用两相介质中地宸波传播理论对实验结果作了定量分析。  相似文献   
958.
本文围绕烃类微渗漏造成地表土壤蚀变的褪红、粘土矿化和碳酸盐化等3项标志,在江汉油田进行了相关的地球化学信息和光谱信息研究。在研究土壤成分特征的基础上,提出了反映3项蚀变标志的成分因子;在研究土壤光谱特征的基础上,提出了与蚀变成分因子相关的TM波段比值因子;在成分因子及TM波段比值因子的统计分析基础上,探索从室内土壤光谱数据中提取和烃类微渗漏蚀变相关的信息,并为图像特征信息提取奠定了基础。  相似文献   
959.
目的:探讨经方治疗晚期肺癌的辨治规律及处方用药。方法:收集中国知网(CNKI)中运用经方治疗晚期肺癌的病案,通过Medcase V5.2仓公诊籍国医脉案数据记录挖掘系统,运用频数分析与关联规则分析,从临床症状、舌象、脉象、病机、处方用药等多方面对经方治疗晚期肺癌的病案进行数据挖掘。结果:晚期肺癌的主要临床表现有咳嗽、疲倦乏力、食欲不振、胸闷、易醒、入睡困难等;频数较高的舌象有舌质暗红、舌质红、舌质淡红、舌质淡、苔薄白、苔黄腻;频数较高的脉象有细、弦、滑、沉、数、弱;病机主要为癌毒郁肺、肺脾气虚、肺失宣肃、肝郁化火、痰热壅肺、水饮停肺;常用药物有茯苓、法半夏、炙甘草、大枣、桂枝、柴胡等;通过关联规则分析,得到30组关联症状、28组关联病机、30组病机与临床症状关联。结论:应用数据挖掘法能够反映经方治疗晚期肺癌的辨治规律,具有一定的临床指导意义。  相似文献   
960.
The origin of the Tertiary ‘red clay’ underlying the Pleistocene loess in the Chinese Loess Plateau remains controversial, although several lines of evidence have suggested a wind‐blown origin. This study examines the particle‐size parameters of the late Miocene and Pliocene ‘red clay’ by comparing it with those of the late Pleistocene loess. The particle‐size distribution of a total of 15 339 loess and 6394 ‘red clay’ samples taken from 12 loess sections along a north–south transect and two ‘red clay’ sequences at Lingtai and Jingchuan was systematically analysed. The median grain size, skewness and kurtosis of the late Pleistocene loess all show a systematic southward change and are principally influenced by distance from source region. The spatial and temporal differentiation of dust deposits is expressed in a skewness–kurtosis–median grain size ternary diagram, from which the distance to the source region can be inferred. The particle‐size characteristics of the Tertiary ‘red clay’ sediments are very similar to those of the palaeosols within the late Pleistocene loess deposits, suggesting an aeolian origin for the ‘red clay’. Based on the comparison of ‘red clay’ and loess in the ternary diagrams, it is inferred that the source–sink distance was greater in the Neogene than in the last and penultimate interglacials, and that the dust source region in north‐western China underwent a progressive expansion during the period from at least 7·0 Ma to the present.  相似文献   
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