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利用常规观测资料、自动站逐时资料及T639数值预报初始场,对2010年3月19日、2011年4月28日甘肃省2次强沙尘暴天气过程从天气概况、气候背景、环流形势及单站地面气象要素、高空急流、垂直速度、稳定度等方面进行深入分析。结果表明:2次过程前期均具有气温偏高、降水稀少的的气候背景;高空斜压槽和强锋区、地面强冷高压和锋前蒙古气旋或热低压是发生此类强沙尘暴的环流形势;高低空急流配置和地面气象要素演变对沙尘暴天气有指示意义;由于2次过程冷空气路径、强度有所差异,因此对甘肃造成的影响不同。 相似文献
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Response of microbial community to petroleum stress and phosphate dosage in sediments of Jiaozhou Bay,China 总被引:1,自引:0,他引:1
ZHAO Yangguo CHEN Min BAI Jie LI Xinwei Farhana Zulfiqar and WANG Qianli 《中国海洋大学学报(英文版)》2014,13(2):249-256
The dynamic microcosms were used to evaluate the effect of oil spills on microbial ecological system in marine sediment and the enhancement of nutrient on the oil removal. The function and structure of microbial community caused by the oil pollution and phosphate dosage were simultaneously monitored by dehydrogenase activity assay and PCR-denaturing gradient gel electrophoresis (DGGE) techniques. The results indicated that the amount of total bacteria in all dynamic microcosms declined rapidly with incubation time. The number of petroleum-degrading bacteria and the activity of sediment dehydrogenase were gradually enhanced by petroleum in the oil-treated microcosms, while they both showed no obvious response to phosphate dosage. In comparison, phosphate spiked heterotrophic bacteria and they showed a significant increase in amount. DGGE profiles indicated that petroleum dosage greatly changed community structure, and the bacteria belonged to class Deltaproteobacteria, and phyla Bacteroidetes and Chlorobi were enriched. This study demonstrated that petroleum input greatly impacted the microbial community structure and consequently the marine sediment petroleum-degrading activity was enhanced. Phosphate dosage would multiply heterotrophic bacteria but not significantly enhance the petroleum degradation. 相似文献
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WU Xinwei ZHANG Chao ZHANG Yujin GUO Wei CUI Tianri YANG Yajun HU Jianfei SONG Wanbing 《《地质学报》英文版》2018,92(3):1265-1266
正Objective The formation and evolution of Songnen massif has always been a hot topic,and the presence of Precambrian basement on the Songnen massif is still controversial:(1)Lacking of Pre-Paleozoic dating results,the Precambrian basement on Songnen massif does not extend largely according to the isotopic dating results of core from basement,(2)the existence of gneiss from deep drill holes 相似文献
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ZHANG Yujin TIAN Ning ZHU Zhipeng WANG Yongdong WU Xinwei ZHANG Zhibin ZHANG Chao SI Qiuliang MA Yongfei 《《地质学报》英文版》2018,92(5):1685-1699
Two new coniferous wood taxa, Protocedroxylon zhangii sp. nov. and P. zhalantunense sp. nov., are described from the Middle Jurassic Wanbao Formation in Zhalantun City, Inner Mongolia, NE China. The new discovery represents the first record of petrified wood in the Wanbao Formation, and contributes to further understanding the floral composition, especially that of the forest, of the Wanbao Formation. Anatomically, the two new species are characterized by having a mixed type of radial pitting and Abietineentüpfelung. In extant conifers, Abietineentüpfelung is considered to be characteristic of the wood of Pinaceae. The new discovery further indicates that the first occurrence of Abietineentüpfelung in conifer-like wood should be earlier than the Kimmeridgian. The palaeolatitudinal distribution pattern of Protocedroxylon indicates that the genus is a palaeobiogeographically consistent group, which was probably restricted to wetter and cooler temperate climates. In combination with distinct growth rings, the occurrence of Protocedroxylon suggests that a cool temperate and seasonal climate might have prevailed during the sedimentation period of the Wanbao Formation in eastern Inner Mongolia, NE China. Such a view is also in agreement with the palaeoclimatic conditions indicated by the plant megafossils of the Wanbao Formation. 相似文献
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浙江长兴“金钉子”灰岩Re Os富集机制研究 总被引:4,自引:0,他引:4
通过对浙江长兴煤山D剖面二叠—三叠"金钉子"灰岩样品Re-Os同位素、主微量元素和有机碳测定,对不同层位灰岩的沉积环境进行了判别。通过分析灰岩主微量元素、有机碳与Re、Os含量的相关性,探索性地研究了灰岩中Re、Os富集机制。研究发现,灰岩中Re、Os的富集主要受氧化还原作用影响,Re只有在还原环境下,才会被灰岩中的有机物富集,此时灰岩中Re含量较高,适用于Re-Os同位素定年,而Re在氧化环境下很难被灰岩中有机质富集。Os在还原环境下同样被有机质富集,但氧化环境下,部分Os也可以被灰岩地层中含铁、铜等自生矿物吸附富集,含铁、铜等自生矿物Os同位素比值可以代表沉积时海水Os同位素特征。Re、Os在灰岩中的富集机制研究对于将Re-Os同位素应用于灰岩地层精确定年及古环境示踪具有重要意义。Re、Os在不同氧化还原条件下的富集差异导致了还原环境沉积的灰岩中187 Re/188 Os要大于氧化环境灰岩中187 Re/188 Os,灰岩中187 Re/188 Os变化对研究古海洋沉积氧化还原环境可能具有一定指示意义。 相似文献
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源汇系统定量化研究是沉积学领域的前缘,是精细重构源汇过程、指导油气储层预测的重要手段。利用重矿物和锆石U Pb年龄对珠江口盆地惠州凹陷惠州27转换带进行物源示踪、定量恢复源区沉积物相对贡献,进而重构古近纪源汇过程,探讨源汇控储作用。研究结果表明,中始新统文昌组重矿物类型复杂、ZTR指数(碎屑岩中碎屑锆石(Zircon)、电气石(Tourmaline)、金红石(Rutile)在透明重矿物碎屑中所占的比例)小,上始新统恩平组重矿物类型简单、ZTR指数大。研究区文昌组—恩平组主要受盆内中生界岩浆岩基底和盆外珠江水系供源。其中文昌组沉积物98%来自于盆内中生界岩浆岩基底;下恩平组沉积物58.4%来自于盆外珠江东北部支流、36.5%来自于盆内中生界岩浆岩基底;上恩平组沉积物73.7%来自于盆外珠江东北部支流、22.2%来自于盆内中生界岩浆岩基底。研究认为,恩平组沉积期现代珠江尚未形成,但珠江东北部支流(即古珠江)已独立发育且携带大量华夏地块碎屑物质汇入惠州凹陷,导致了惠州27转换带“文昌期盆内近源—恩平期盆外、盆内混源”的源汇转换过程,而非简单的“盆内近源—盆外远源”转换。源汇转换过程改变了恩平组储层的岩石组分,进而改善了储层物性,也使得其储层非均质性变强。本研究定量解析了惠州凹陷古近纪源汇转换过程,为陆相断陷盆地定量源汇及其应用提供了新视角。 相似文献
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