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661.
662.
Grateloupia ramosa Wang & Luan sp. nov. (Halymeniaceae, Rhodophyta) is newly described from Hainan Province, southern China. The organism has the following morphological features: (1) purplish red, cartilaginous and lubricous thalli 5–10 cm in height; (2) compressed percurrent axes bearing abundant branches with opposite arrangement; (3) claw-like apices on top, constricted to 2–4 cm at the base; (4) cortex consisting of 3–6 layers of elliptical or anomalous cells and a medulla covered by compact medullary filaments; (5) reproductive structures distributed throughout the thallus, especially centralized at the bottom of the end portion of the branches; and (6) 4-celled Carpogonial branches and 3-celled auxiliary-cell branches, both of the Grateloupia-type. The morphological diff erences were supported by molecular phylogenetics based on ribulose-1, 5-bisphosphate carboxylase/oxygenase (rbcL) gene sequence analysis. There was only a 1 bp divergence between specimens collected from Wenchang and Lingshui of Hainan province. The new species was embedded in the large Grateloupia clade of the Halymeniaceae. The pairwise distances between G. ramosa and other species within Grateloupia ranged from 26 to 105 bp, within pairwise distances of 13–111 bp between species of the large genus Grateloupia in Halymeniaceae. Thus, we propose this new species as G. ramosa Wang & Luan sp. nov.  相似文献   
663.
The lower Cambrian develops a set of organic-rich black shales in Yangtze Platform and is regarded as one of the key layers of shale gas exploration. The microscope pore structure characteristics and methane sorption capacity were investigated using scanning electron microscope, nitrogen adsorption and methane sorption experiments, and then their controlling factors combining with organic matter, mineral compositions were discussed for Niutitang shales in Zunyi area, Mufushan shales in Nanjing area and Huangboling shales in Chizhou area. The results show as below; ( I ) The pores in lower Cambrian shales are mainly dominated by organic pores, interlayer pores in clay minerals and micro-fractures, as well as containing some intergranular pores between brittle mineral grains, honeycomb poies formed by pyrite crystals falling out, and dissolution molds in fossils; ( 2) DKT pore size distributions show the pores is mainly concentrated in the range of less than 4 nm in lower Cambrian shales and kerogens, while a certain amount of pores are above 4 nm are also existed in lower Cambrian shales, which may be contributed by smectite; ( 3)The specific surface area, pore volume and Langmuir methane sorption capacity of the lower Cambrian shales are ranging from 5.58 to 31. 96 inVg, 0.026 to 0.088 mL/g and 1.36 to 5. 3 mL/g, respectively, which are mainly controlled by TOC and smectite contents, but the effect of TOC and smectite on physical properties are quite different for the lower Cambrian shales in different regions; ( 4)The specific surface area of two Niutitang kerogens are 7. 08 and 7. 92 times than that of the shales and methane sorp-Tion capacity of kerogens arc 5.81 and 7.09 times than that of the shales, suggesting that kerogen is a main carrier of methane gas occurrence in.  相似文献   
664.
基于CHAMP卫星高精度磁场观测数据,对2001—2009年径向行星际磁场(RIMF, radial interplanetary magnetic fields)条件下的场向电流的分布特征进行了统计学分析, 并与2001—2009年期间场向电流的平均强度进行了对比研究, 结果表明:正午时刻场向电流的平均强度对地偶极子倾角有明显线性依赖, 冬夏季电流强度比值约为3左右, RIMF条件下冬夏季比值降为2;相对年平均值来说, RIMF条件下行星际磁场总幅度、重联电场、太阳风动压均有所减小, AE指数减弱, Dst指数略有降低;在通常情形下重联电场是场向电流很好的控制参数, 但是在RIMF下, 重联电场不再与电流强度相关;北半球电流强度在向地IMF条件下大于向日IMF, 而南半球则相反, 虽然RIMF条件下场向电流的均值小于年平均值, 但是正午时段场向电流强度大于年平均值的概率大约为0.2, RIMF条件下仍然有地磁扰动事件(比如亚暴事件)发生。  相似文献   
665.
极地产甲烷菌研究进展   总被引:1,自引:0,他引:1       下载免费PDF全文
产甲烷菌是一类重要的环境微生物,其代谢产生的甲烷(CH_4)是最重要的温室气体之一。现有研究表明,产甲烷菌广泛存在于极地湿地、沼泽、湖泊、苔原、冻土和冰川等各类生境之中,并在碳循环中发挥着重要作用。本文对极地产甲烷菌的群落结构、生物多样性、空间分布、环境影响因子(温度﹑营养物和pH)以及研究技术的最新进展进行了总结,并对极地产甲烷菌研究的未来发展进行了展望。  相似文献   
666.
Based on the prefecture-level data of the 2000 and 2010 national censuses, the spatial evolution of China’s semi-urbanization is analyzed in this study. The stages of urbanization are re-examined by considering semi-urbanization. Nine types of urban development are presented according to the relations between semi-urbanization and urbanization, and China’s urbanization is divided into five stages, namely, high incoordination, incoordination, low coordination, coordination, and high coordination. Results show that China’s semi-urbanization rate varies significantly from one area to another; its order in 2010 from the highest to the lowest value was as follows: east, middle, west, and northeast. Urbanization and semi-urbanization rates in inland cities increase much faster than those in coastal cities. In addition, semi-urbanization displays a spatial pattern similar to that of urbanization across China, with the sole exception of the northeastern region. Through a spatial autocorrelation analysis, the spatial concentration of semi-urbanization is determined to be increasing. High-value concentration areas are expanding in the coastal east, whereas low-value concentration areas are growing in the northeast. Lastly, the evolution of China’s urbanization model suggests a weakening trend of coordination between urbanization and semi-urbanization over the studied decade. Semi-urbanization can be viewed as a special production of China’s hukou system, which restricts the permanent settlement of migrants in cities. As such, China’s semi-urbanization trend is expected to exhibit a reversed U-shaped pattern as urbanization and citizenization develop.  相似文献   
667.
朱君  曹晓钟  李晓兰 《气象科技》2017,45(4):611-615
选取激光云高仪观测的云高和可见光测云仪观测的云量,通过对比两种地面云观测设备观测数据在相同条件下的差异,分析不同要素对设备观测性能的影响,结果表明:在相同观测条件下,两种地基云观测设备的观测结果不同;激光云高仪和可见光测云仪受雾、霾、降水等天气现象以及云物理特性的影响,云观测数据会出现的漏报和误报的现象;激光云高仪还受自身探测高度和垂直分辨率的影响,对高云和薄云的捕获率较差。  相似文献   
668.
本文论述了作者所研制的YZ-III型遥测波浪仪的原理、结构和性能。该仪器具有利用加速度原理工作、高精度、高分辨率、高可靠性和连续工作等特点。介绍了该仪器系统动态标定和海上试验情况。  相似文献   
669.
818-01专题区域数据处理中心网络系统的设计与建立   总被引:1,自引:0,他引:1  
本文综述了上海海洋环境立体监测和信息服务系统中的一级数据处理中心网络系统的设计与集成,并形成了区域性海洋环境立体监测和信息服务网络系统设计模式,为我国海洋环境立体监测系统建议奠定技术基础。  相似文献   
670.
South of Hangzhou Bay, Zhejiang Province, exhibits an embayed muddy coastline, with the muddy beaches of embayments extending continuously seaward.The source of sediments on this coast presents an interesting problem to marine geologists and geomorphologists .The total annual load of sediments from the rivers of Zhejiang is only 12×106t.These materials affect only the area near the river mouths. The paper showed that the sediment along the coast of Zhejiang mainly comes from the Changjiang Estuary through analysing the time and space variations of suspended sediment, the features of sediment and the sedimentary transport.The Changjiang River is the largest river system in China, its sediment to the sea amounting to 468×106t. The sediment during summer transports mainly eastward, and is affected by the water body with high temperature, salinity and transparency; the winter season is the period with high sediment concentration. The sediment of the Changjiang Estuary transports together with the longshor  相似文献   
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