全文获取类型
收费全文 | 203篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 1篇 |
大气科学 | 8篇 |
地球物理 | 39篇 |
地质学 | 103篇 |
海洋学 | 10篇 |
天文学 | 26篇 |
自然地理 | 23篇 |
出版年
2021年 | 3篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 7篇 |
2011年 | 4篇 |
2010年 | 7篇 |
2009年 | 14篇 |
2008年 | 7篇 |
2007年 | 11篇 |
2006年 | 5篇 |
2005年 | 11篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1997年 | 5篇 |
1982年 | 3篇 |
1979年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1965年 | 1篇 |
1922年 | 1篇 |
1921年 | 3篇 |
1918年 | 2篇 |
1917年 | 1篇 |
1915年 | 2篇 |
1912年 | 2篇 |
1910年 | 3篇 |
1908年 | 2篇 |
1905年 | 1篇 |
1902年 | 5篇 |
1900年 | 5篇 |
1899年 | 2篇 |
1898年 | 2篇 |
1897年 | 2篇 |
1895年 | 1篇 |
1890年 | 1篇 |
1889年 | 3篇 |
1887年 | 2篇 |
1885年 | 1篇 |
1882年 | 1篇 |
1880年 | 2篇 |
1875年 | 1篇 |
排序方式: 共有210条查询结果,搜索用时 312 毫秒
1.
2.
3.
4.
Regional variation in maturation of sandeels in the North Sea 总被引:1,自引:0,他引:1
5.
A population of killifish (Fundulus heteroclitus) inhabiting a creosote-polluted inlet of the Elizabeth River demonstrates tolerance to the acute toxic effects exerted by contaminated sediments on reference site killifish. Previous data have suggested that upregulated antioxidant defenses contribute to short-term tolerance in killifish exposed to Elizabeth River sediments. This study investigated population differences in antioxidant defenses from wild caught Elizabeth River and reference population killifish in different seasons, and after being held in the laboratory. Parameters measured in the killifish were total glutathione concentrations (GSH(T)), activities of glutathione reductase (GR), glutathione peroxidase (GPx), and lipid peroxidation (LPO), all in adult hepatic tissues. The Elizabeth River population exhibited greater GSH(T), higher GPx activities, and increased LPO as compared to the reference population. Sex specific population differences were also observed in GSH(T) and GPx. Both populations displayed decreased GSH(T) and increased GR from early to late summer, as well as after being held in the laboratory. This study indicates that there are many factors that may contribute to differences in levels of antioxidant defenses in addition to exposure to contaminants, including reproductive status and environmental conditions. 相似文献
6.
7.
8.
Natural Hazards - Driving after natural disasters entails a substantial amount of stress; therefore, the number of motor vehicle crashes may increase. However, few studies have examined this issue.... 相似文献
9.
Richard A. Staff Takeshi Nakagawa Gordon Schlolaut Michael H. Marshall Achim Brauer Henry F. Lamb Christopher Bronk Ramsey Charlotte L. Bryant Fiona Brock Hiroyuki Kitagawa Johannes van der Plicht Rebecca L. Payne Victoria C. Smith Darren F. Mark Alison Macleod Simon P. E. Blockley Jean‐Luc Schwenninger Pavel E. Tarasov Tsuyoshi Haraguchi Katsuya Gotanda Hitoshi Yonenobu Yusuke Yokoyama Suigetsu Project Members 《Boreas: An International Journal of Quaternary Research》2013,42(2):259-266
The varved sediment of Lake Suigetsu (central Japan) provides a valuable opportunity to obtain high‐resolution, multi‐proxy palaeoenvironmental data across the last glacial/interglacial cycle. In order to maximize the potential of this archive, a well‐constrained chronology is required. This paper outlines the multiple geochronological techniques being applied – namely varve counting, radiocarbon dating, tephrochronology (including argon–argon dating) and optically stimulated luminescence (OSL) – and the approaches by which these techniques are being integrated to form a single, coherent, robust chronology. Importantly, we also describe here the linkage of the floating Lake Suigetsu (SG06) varve chronology and the absolute (IntCal09 tree‐ring) time scale, as derived using radiocarbon data from the uppermost (non‐varved) portion of the core. This tie‐point, defined as a distinct (flood) marker horizon in SG06 (event layer B‐07–08 at 1397.4 cm composite depth), is thus derived to be 11 255 to 11 222 IntCal09 cal. years BP (68.2% probability range). 相似文献
10.
Fiona S. Tweed 《Geology Today》2012,28(6):217-223
Volcanic eruptions generate hazards, are potent agents of landscape change and have the power to alter global climate. Recent events in Iceland have emphasised the multi‐scale and trans‐boundary nature of hazards from ice‐volcano interactions and have highlighted their local, national and international impacts. Prompted by these recent events, this article reviews a selection of Icelandic volcanic eruptions in order to demonstrate the diversity of hazards and impacts generated by Icelandic volcanic activity. Some of the challenges associated with managing risks from Icelandic volcanic hazards are discussed and future prospects are outlined. 相似文献