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991.
长江中下游地区7500—5000aB.P.气候变化序列的初步研究 总被引:5,自引:0,他引:5
孢粉分析方法可以比较客观地反映古植被类型,而各植被类型只能在一定的气候指标范围内生长。本文根据这一基本原理,利用现代植被生长的基本气候指标和有关气象资料,对长江中下游地区7500—5000aB.P.的孢粉资料进行处理、转化,从而得出这一阶段每500年一个时间段的气候变化序列。研究结果表明,研究区在7500—5000aB.P.时间内,年平均温度偏暖于今日-0.1—1.5℃,最高温出现在6500—6000aB.P.,气温高于现在1.5℃。 相似文献
992.
异沙珊瑚(Heteropsammia)是仅分布于印度西太平洋热带和亚热带浅海区的一个属,隶石珊瑚目,因与星虫共栖而著名,过去共报道过8种,但在本世纪七十多年中,未增添过一个新种。经Horst(1922 、1926) 、Yabe and Eguchi(1932、1942)等人的分类研究和归并后,迄今一般认为,该属只有4种,即:单体珊瑚两种——H.cochlea (Spengler)和H.ovalis Semper,单体兼群体珊瑚一种——H. michelinii Milne-Edwards and Haime,群体珊瑚一种——H.geminata VetriIl。
我们在整理1958-1960年中国近海海洋调查所采集的与星虫共栖的石珊瑚标本时,发现在海南岛西南近岸水域拖网采到的一个异沙珊瑚标本,其形态特征与该属己记载的种都不相同,经详细研究后,确定是一个新种。 相似文献
993.
Preliminary study on concentrations and size distribution of marine aerosols over the East China Sea
In summer and winter, 1987,and in spring and autumn, 1988, the concentrations and size distribution of marine aerosols were measured over the East China Sea and the South Japan Sea. This paper deals with the study on the seasonal variation of the marine aerosols with the meteorological parameters, the differences and the relations between the marine and continental aerosols. The results show that the marine aerosol concentrations and size distribution over the East China Sea have distinct seasonal change characteristics, which may be attributed to the East Asian atmospheric circulation. The size distribution is discussed by using a three-parameter size distribution model. 相似文献
994.
16例烧伤病人应用CHIMEHERB人工皮覆盖26个创面,其中浅Ⅱ°及部分深Ⅱ°创面11个,深Ⅲ°削痂创面10个,切削痂覆盖自体网状皮创面5个,与辐照猪皮对照观察,临床获得较好效果.认为在有效的清创及正确的创面处理下覆盖人工皮能减少创面渗出,有利创面愈合.作为一种新型的生物性敷料,无同种异体皮或异种皮移植时的排异现象,但其本身不具抗菌能力. 相似文献
995.
996.
Processing Multibeam Backscatter Data 总被引:1,自引:0,他引:1
A new highly precise source of data has recently become available using multibeam sonar systems in hydrography. Multibeam sonar systems can provide hydrographic quality depth data as well as high-resolution seafloor sonar images. We utilize the seafloor backscatter strength data of each beam from multibeam sonar and the automatic classification technology so that we can get the seafloor type identification maps. In this article, analyzing all kinds of error effects in backscatter strength, data are based on the relationship between backscatter strength and seafloor types. We emphasize particularly analyzing the influences of local bottom slope and near nadir reflection in backscatter strength data. We also give the correction algorithms and results of these two influent factors. After processing the raw backscatter strength data and correcting error effects, we can get processed backscatter strength data which reflect the features of seafloor types only. Applying the processed backscatter strength data and mosaicked seafloor sonar images, we engage in seafloor classification and geomorphy interpretation in future research. 相似文献
997.
对南沙群岛海域87-11柱样天然剩余磁化强度(NRM)及90-103柱样NRM、磁化率(x)、剩磁倾角(Ⅰ)等的功率谱分析表明:晚更新世以来该区沉积物的古地磁参数较好地反映了古气候、古环境的变化,响应着古气候变化的米兰科维奇天文学周期;在周期成分中,以地球轨道偏心率周期(e)及岁差周期(p)为主,地轴倾斜度周期(ε)无明显表现,同时获得了与特殊地球位置相关联的岁差半周期成分。研究还表明,古地磁参数存在着明显的对古气候变化的非线性响应,明显不同于开阔大洋;同时,不同的沉积单元,沉积物古地磁参数对古气候变化响应的灵敏度各不相同。 相似文献
998.
Analysis of influencing factors on fine sediment flocculation in the Changjiang Estuary 总被引:1,自引:0,他引:1
Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influencing factors are water temperature, settling time, salinity, grain size, sediment concentration and current velocity according to the correlation coefficients. Among them, the salinity and the sediment grain size are critical type influencing factors (CrTIF); the settling time, the sediment concentration and the velocity are continuous type influencing factors (CoTIF); and the water temperature has the characteristics of both. When the critical values of CrTIF are reached or exceeded, the fine sediments will be flocculated, but values of CrTIF will not influence the settlement strength of floes. The influence of CoTIF is continuous. The values of the CoTIF will not only influence the occurrence of flocculation but also the settlement strength of the floes. 相似文献
999.
Xidong Chen Douglas F. Williams Yuan Youren Wang Baogui Tang Xianzan Fan Shiqing Liu Zongyang 《海洋学报(英文版)》1992,11(4):573-581
Signal processing techniques of cross-correlation, power spectral analysis and cross-power spectral analysis are used to determine the relationships between paleomagnetic properties and the oxygen isotope record of the South China Sea during the late Pleistocene. On the basis of correlation tests between the δ18O time series of cores V3 and A15 with the paleomagnetic properties of core SCS01, five events of susceptibility and intensity of natural remanent magnetization are identified as glacial events corresponding to δ18O positive events. The magnetic properties of the sediments which are independent of the geomagnetic field are sensitive climatic indicators which have frequencies corresponding to the Milankovitch orbital parameters. 相似文献
1000.
This paper uses the density functional theory to analyse the stabilities, bond characters, static linear polarisabilities, and aromaticities of the `in-out' isomerism Hn-60@CnH60 (n=70, 72, 74). The binding energies, C--H bond energies, and energy gaps explore that the `in-out' isometric perhydrogenation of Cn (n=70, 72, 74) can remarkably improve the stabilities. The static linear polarisabilies of Hn-60@CnH60 (n=70, 72, 74) are indeed relative to their shapes, while they show almost nonaromatic character. This study can suggest that the `in-out' isometric perhydrogenation of fullerenes could lead to the invention of entirely novel potential hydrogen storage nanomaterials. 相似文献