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Jun Takahashi Tatsuo Suzuki Igor V Polyakov Kohei Mizobata Moto Ikeda Fancois J.Saucier Markus Meier 《极地研究(英文版)》2008,19(2):159-167
This study investigates the Arctic Ocean warming episodes in the 20th century using both a high-resolution coupled global climate model and historical observations. The model, with no flux adjustment, reproduces well the Atlantic Water core temperature (AWCT) in the Arctic Ocean and shows that four largest decadalscale warming episodes occurred in the 1930s, 70s, 80s, and 90s, in agreement with the hydrographic observational data. The difference is that there was no pre-warming prior to the 1930s episode, while there were two pre-warming episodes in the 1970s and 80s prior to the 1990s, leading the 1990s into the largest and prolonged warming in the 20th century. Over the last century, the simulated heat transport via Fram Strait and the Barents Sea was estimated to be, on average, 31.32 TW and 14.82 TW, respectively, while the Bering Strait also provides 15.94 TW heat into the west- ern Arctic Ocean. Heat transport into the Arctic Ocean by the Atlantic Water via Fram Strait and the Barents Sea correlates significantly with AWCT ( C = 0.75 ) at 0- lag. The modeled North Atlantic Oscillation (NAO) index has a significant correlation with the heat transport ( C = 0.37 ). The observed AWCT has a significant correlation with both the modeled AWCT ( C =0.49) and the heat transport ( C =0.41 ). However, the modeled NAO index does not significantly correlate with either the observed AWCT ( C = 0.03 ) or modeled AWCT ( C = 0.16 ) at a zero-lag, indicating that the Arctic climate system is far more complex than expected. 相似文献
104.
Huan WU Xiaomeng LI Guy J.-P.SCHUMANN Lorenzo ALFIERI Yun CHEN Hui XU Zhifang WU Hong LU Yamin HU Qiang ZHU Zhijun HUANG Weitian CHEN Ying HU 《大气科学进展》2021,38(1):1-7
The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes,caused flash flooding,urban flooding and landslides,and consistently wreaked havoc across large swathes of China,particularly in the Yangtze River basin.Significant precipitation and flooding anomalies have already been seen in magnitude and extension so far this year,which have been exerting much higher pressure on emergency responses in flood control and mitigation than in other years,even though a rainy season with multiple ongoing serious flood events in different provinces is not that uncommon in China.Instead of delving into the causes of the uniqueness of this year’s extreme precipitation-flooding situation,which certainly warrants in-depth exploration,in this article we provide a short view toward a more general hydrometeorological solution to this annual nationwide problem.A“glocal”(global to local)hydrometeorological solution for floods(GHS-F)is considered to be critical for better preparedness,mitigation,and management of different types of significant precipitation-caused flooding,which happen extensively almost every year in many countries such as China,India and the United States.Such a GHS-F model is necessary from both scientific and operational perspectives,with the strength in providing spatially consistent flood definitions and spatially distributed flood risk classification considering the heterogeneity in vulnerability and resilience across the entire domain.Priorities in the development of such a GHS-F are suggested,emphasizing the user’s requirements and needs according to practical experiences with various flood response agencies. 相似文献
105.
The improvement on the calculation of anti-Stokes energy transfer rate is studied in the present work. The additional proportion coefficient between Stokes and anti-Stokes light intensities of quantum Raman scattering theory as compared with the classical Raman theory is introduced to successfully describe the anti-Stokes energy transfer. The theoretical formula for the improvement on the calculation of anti-Stokes energy transfer rate is derived for the first time in this study. The correctness of introducing coefficient exp{ΔE / kT} from well-known Raman scatter theory is demonstrated also. Moreover, the experimental lifetime measurement in Er0.01YbxY1 - 0.01 - xVO4 crystal is performed to justify the validity of our important improvement in the original phonon-assisted energy transfer theory for the first time. 相似文献
106.
俄勒冈州外海水合物脊现代甲烷渗漏区的发现,为研究甲烷对活体有孔虫生态和地球化学方面的影响提供了机会。2002年在水合物脊南部高点获取一批岩心。样品经保存和染色后用来测定Uvigerina peregrina、Cibicidoidesmckannai和Globobuliminaauriculata3个底栖有孔虫属种的活体(经染色)和死体的碳同位素(δ13C)组成。有孔虫样经光学显微镜和扫描电镜检查,未发现有成岩作用或自生碳酸盐沉淀作用的迹象。渗漏区活底栖有孔虫单体记录的乎δ13C值在-0.4%--21.2%0之间,说明受高浓度甲烷碳同位素的影响。渗漏区底栖有孔虫护C平均值(由单体样品计算)范围在-1.28%--5.64%0之间,而背景区(没有甲烷渗漏)的介于-0.81%--0.85%之间。为了解环境因素对底栖有孔虫δ13C值的影响,对细菌席和蛤床两种截然不同的甲烷渗漏环境的底栖有孔虫进行研究。细菌席区的有孔虫单体比蛤床区的具有更负的δ13C值。我们解释这种差异是食物来源或共生细菌对底栖有孔虫δ13C值影响的结果,通过溶解无机碳(DIC)作用于底栖有孔虫,使其δ13C值负偏移。对比活体和死体底栖有孔虫的δ13C值,并未发现统计上的差异。这说明自生碳酸盐沉淀作用未在观测到的同位素组成中起主导作用。然而,少量极度亏损δ13C(〈-12%)的死体底栖有孔虫确实显示了自生碳酸盐岩沉积对有孔虫δ13C值影响的潜在证据。 相似文献
107.
The diagnosis of the conchostracan genus Tenuestheria from the Lanxi Formation in Jinhua, Zhejiang Province in Southeast China is revised following an examination of the type species under a scanning electron microscope, which revealed some morphological features on the carapace that had not been recognized previously. The importance of the Tenuestheria Fauna is considered in the context of correlation of six Turonian–Santonian formations in this region of China. The value of the Cenomanian Nemestheria and Turonian Linhaiella faunas in correlating the underlying early Late Cretaceous formations is also noted. 相似文献
108.
《古地理学报》编辑部 《古地理学报》2007,9(2):184-184
《冯增昭文集》是庆祝冯增昭教授80华诞及从事地质教育工作55年而出版的综合性地学类著作。全书包括4个部分:第一部分为岩相古地理学文章20篇,第二部分为沉积学文章及其他文章13篇,第三部分为17部沉积学及岩相古地理学专著的序,第四部分为6部沉积学翻译著作的序及两篇译文;还有 相似文献
109.
在含金碳酸盐矿床的表生交代作用中,形成的风化流体倾向于碱性,因此,不适于金呈氯的络合物迁移的媒介,而在这种矿床中次生金的再活化常可归因于金与含硫配体的络合作用。通过可靠的热动力学计算,金、银分别在Au—S—O_2—H_2O和Ag—S—O_2—H_2O体系中的溶解度与金和硫代硫酸盐及二硫化物配体络合物的形成有关。最稳定的络离子是Au(S_2O_3)2~(3-)(当fO_2>10~(60))和Au(HS)_2~-(当fO_2<10~(60)),它们存在于中性或碱性溶液中。类似于金,银在中等氧化环境中形成一个稳定的硫代硫酸盐络离子Ag(S_2O_3)2~(3-),在还原、碱性介质中形成二硫化物络离子AgHS~D和Ag(HS)_2~-。在强氧化的中性或酸性溶液中,由于AgS_2O_3~-、Ag~+和AgSO_4~-络离子的形成,使Ag的溶解度增高。然而,胶态的、晶质的及呈合金态的金和银与0.1molNaS_2O_3溶液反应没有显示各自独立的溶解度。以金为例,其在0.1molNa_2S_2O_3溶液中的溶解度由于银的硫代硫酸盐络离子及合金态的银的存在而增高,这种性质可能与形成混合金属络离子(Au,Ag)(S_2O_3)2~(3-)有关。在巴布亚新儿内亚的Wau地区,碳酸盐矿床氧化代中次生金的性质和矿物组合与早期硫作为硫代硫酸盐络离子的再活化是一致的。这里的次生金是粗大结晶的,与50~75at%(原子百分此)的银组成合金,富集于潜水面上,并与二氧化锰共生于氧化带中。 相似文献
110.
滑脱断层带内流体与岩石相互作用的构造样式 总被引:1,自引:0,他引:1
北美科迪勘拉地区变质核部杂岩体和相关的滑脱断层表现为缓倾斜、正向位移型剪切带(滑脱断层带),热的深层地壳沿着滑脱断层带从脆性扩张的上盘岩板下面上和向外运移。滑脱断层带由韧性向脆性演化期间形成的构造,可以用来恢复剪切带内不同层次的流体压力和差应力的相对大小。发生在脆韧性过渡带以下滑脱断层更深地段的糜棱岩化作用,局部地伴随有指示低的偏应力和商的流体压力的张性破裂。这种状态说明最早期是脆性变形,然后由于流体压力的降低和偏应力的升高而形成了剪性破裂。在低的流体压力条件下,上盘岩扳岩石广泛发育脆性变形。构造和地球化学资料说明,滑脱断层带上的正向位移导致了两套流体系统的形式:(1)以近静水压力下大气的和同生的流体占优势,并通过热对流驱动的上盘岩板系统,(2)剪切带更深层次内的系统,此处流体主要来自岩浆源,而流体迁移服从扩容泵机制。滑脱断层带上正向位移的晚期,在构造上使受两套流体系统影响的岩石同时存在,并局部地使剪切带岩石经受与上盘岩扳流体系统相关的矿化作用的影响。 相似文献