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351.
1961—2010年讨赖河山区径流变化特征及其驱动因素 总被引:2,自引:0,他引:2
以1961—2010年讨赖河山区气温、降水和径流资料为基础,综合运用线性趋势、距平百分比、重标极差、Mann-Kendall突变检测、小波变换和多元线性回归等多种数理分析方法,研究了讨赖河山区径流的年内和年际变化规律,并探讨了气候变化和人类活动对径流变化的影响。结果表明:径流年内分配极不均匀且呈单峰型分布,汛期径流占年径流的比重为62.11%。径流经历了“丰-枯-丰-枯”4次波动,在1984年发生由多到少的显著性突变,但整体呈不显著减少趋势且具有持久性。径流在22年准周期上振荡最为明显,经历了“少-多-少-多-少-多-少”7次循环交替,2010—2015年径流可能再次偏多。近50年来山区气温呈“稳定波动-快速上升”变化,降水量呈显著增加趋势,但山区降水转化为径流的比例减少。气温升高和降水量增加引起的蒸散发增加,同时气候变化和人类活动共同作用下的地表覆盖类型的变化均对径流变化产生影响。 相似文献
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Aziz Ghaderpour Khairul Nazrin Mohd Nasori Li Lee Chew Ving Ching Chong Kwai Lin Thong Lay Ching Chai 《Marine pollution bulletin》2014
The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public. 相似文献
354.
2017年6月1日,美国总统特朗普正式宣布退出《巴黎协定》,有关美国退协原因、后续影响和应对策略的研究成为国际社会关注的焦点。本文基于自主构建的美国政策评估模型,综合定性定量分析,系统评估了美国宣布退出《巴黎协定》可能造成的全球气候变化减缓、资金和治理"三大赤字",并据此提出中国的应对策略和建议。研究表明,考虑美国退协对后续政策的影响,美国2030年的排放将有可能达57.9(56.0~59.8)亿t CO2-eq,仅相当于在2005年的水平上下降12.1%(9.1%~15.0%),相对自主贡献目标情景将上升16.4(12.5~20.1)亿t CO2-eq,额外增加8.8%~13.4%的全球减排赤字。美国拒绝继续履行资金支持义务还将使得本不充裕的气候资金机制更加雪上加霜,绿色气候基金(GCF)的筹资缺口将增加20亿美元,而长期气候资金(LTF)的缺口每年将增加50亿美元左右。这就要求欧盟和日本对GCF的捐助至少上升40%,同时欧盟及其成员国的长期资金支持至少上浮25.2%才能填补上述资金赤字。美国是全球气候博弈的重要一方,且美国退协的影响已蔓延至全球治理的主要议事平台,期望中欧、基础四国+等模式短期内迅速填补美国退出后全球气候治理的治理赤字是不现实的,政治推动乏力的情况可能会在今后一段时期内始终存在。虽然国际社会对中国领导全球气候治理充满期待,但中国应有清醒认识,全面评估"接盘"美国领导力的成本、效益和可行性,并秉持"国家利益"优先的原则,谋定而后动。同时,中国应聚焦国内工作,凝聚应对气候变化的战略共识,做好长期战略谋划,并积极推动国际社会从合作中寻找出路应对"三大赤字"难题。 相似文献
355.
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357.
Fengmei Chai Jingwen Mao Lianhui Dong Fuquan Yang Feng Liu Xinxia Geng Zhixin Zhang 《Gondwana Research》2009,16(2):189
The Altay orogenic belt (AOB), situated in the middle part of the Central Asian Orogenic Belt (CAOB), is one of the most important metallogenic belts in China. The Kangbutiebao Formation is a Late Paleozoic stratigraphic unit that hosts many important iron and Pb–Zn deposits. The Kangbutiebao Formation consists of intercalated volcanic and sedimentary rocks that have undergone regional greenschist to lower amphibolite facies metamorphism, and mainly outcrops in three NW-trending fault-bounded volcano–sedimentary basins, including the Maizi, Kelang, and Chonghuer basins. SHRIMP analyses of zircons from three metarhyolites of the Kangbutiebao Fm. in the Kelang Basin yield weighted mean 206Pb/238U ages of 412.6 ± 3.5 Ma, 408.7 ± 5.3 Ma and 406.7 ± 4.3 Ma, respectively, which can be interpreted as the eruption age of the Kangbutiebao silicic volcanic rocks in the Kelang Basin. These ages indicate that the Kangbutiebao Formation was formed during the Late Silurian to Early Devonian. They also demonstrate that the deposits hosted in the Kangbutiebao Formation were formed after 412–407 Ma. They play a key role in understanding the Paleozoic tectonic evolution and metallogenesis of the southern margin of the Chinese AOB. 相似文献
358.
GUO Yuping SONG Hao NIE Rui LI Qi YAN Wenquan SI Fei ZHAO Zichao YAO Chang LI Wei 《《地质学报》英文版》2019,93(Z2):96-97
In recent years, China has carried out large‐scale exploration, exploitation and utilization of geothermal resources, but there is no unified understanding of the distribution characteristics of geothermal field and the controlling factors of forming geothermal field. As for the heat source, some scholars think it is the contribution of radioactivity, fault, magma chamber, or an abnormal heat source, and even the heat generated by the influence of the tectonic movement. As a result, many exemplary geothermal explorations have made great mistakes. After drilling at a depth of 3000‐5000m, the temperature obtained is not as good as the common low‐temperature sedimentary basin, and the losses are huge and extremely uneconomical. 相似文献
359.
Huichao Zhang Peng Chai Hongrui Zhang Zengqian Hou Shouming Chen Yanbin Sun Qing Peng 《Resource Geology》2019,69(3):270-286
The Laowangzhai gold deposit, located in the Ailaoshan gold belt (SW China), is hosted in various types of rocks, including in quartz porphyry, carbonaceous slate, meta‐sandstone, lamprophyre, and altered ultramafic rocks. In contrast to other wall rocks, the orebodies in altered ultramafic rocks are characterized by the occurrence of a large amount of Ni‐bearing minerals. The ore‐forming process of the orebodies hosted by altered ultramafic rocks can be divided into two stages: pyrite‐vaesite‐native gold and gersdorffite‐violarite stages. The contents of As and Sb increased during the evolution of ore‐forming fluid based on the mineral assemblages. Thermodynamic modeling of the Ni‐Cu‐As‐Fe‐S system using the SUPCRT92 software package with the updated database of slop16.dat indicates the fS2 in ore‐forming fluid decreases significantly from stage I to stage II. The decreases of fS2 due to crystallization of sulfides and fO2 due to fluid–rock reaction were responsible for ore formation in altered ultramafic rocks of the Laowangzhai gold deposit. Geological evidence, the in situ sulfur isotope values of pyrite, and the other published isotopic data suggest that the ore‐forming fluid for ultramafic rock ores was dominantly composed of evolved magmatic fluid with the important input of sediments. 相似文献
360.
探讨了培养温度、pH、光照、种龄、接种量以及培养时间等培养条件对破囊壶菌ThraustochytriumroseumMF2生长及其产DHA的影响。结果表明 ,T roseumMF2生长及其产DHA的适宜条件为 :培养温度 2 5℃、初始pH值 6~ 7、种龄 4 8h、接种量 4 %、培养时间 4d ,生物量达到 1 0 4g L ,DHA产量达到1 2 6 6mg L。 相似文献