全文获取类型
收费全文 | 22694篇 |
免费 | 1212篇 |
国内免费 | 632篇 |
专业分类
测绘学 | 1115篇 |
大气科学 | 398篇 |
地球物理 | 688篇 |
地质学 | 2733篇 |
海洋学 | 275篇 |
天文学 | 16460篇 |
综合类 | 1094篇 |
自然地理 | 1775篇 |
出版年
2024年 | 46篇 |
2023年 | 115篇 |
2022年 | 258篇 |
2021年 | 218篇 |
2020年 | 220篇 |
2019年 | 280篇 |
2018年 | 173篇 |
2017年 | 234篇 |
2016年 | 229篇 |
2015年 | 346篇 |
2014年 | 396篇 |
2013年 | 348篇 |
2012年 | 500篇 |
2011年 | 542篇 |
2010年 | 551篇 |
2009年 | 1716篇 |
2008年 | 1696篇 |
2007年 | 1948篇 |
2006年 | 1970篇 |
2005年 | 1778篇 |
2004年 | 1902篇 |
2003年 | 1608篇 |
2002年 | 1385篇 |
2001年 | 1234篇 |
2000年 | 983篇 |
1999年 | 942篇 |
1998年 | 1090篇 |
1997年 | 252篇 |
1996年 | 111篇 |
1995年 | 270篇 |
1994年 | 301篇 |
1993年 | 133篇 |
1992年 | 78篇 |
1991年 | 92篇 |
1990年 | 77篇 |
1989年 | 133篇 |
1988年 | 85篇 |
1987年 | 84篇 |
1986年 | 78篇 |
1985年 | 39篇 |
1984年 | 27篇 |
1983年 | 24篇 |
1982年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1977年 | 6篇 |
1905年 | 3篇 |
1900年 | 3篇 |
1897年 | 7篇 |
1877年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
ZHANGPing-yu MAYan-ji YUZhen-han 《中国地理科学(英文版)》2002,12(4):315-320
Manzhouli is the largest land port city on the Sino-Russia border, transit cargo through the land port amount-ed to 5.95 million tons, transit tourists were 304 500 in 2000. It stands at the joint place of China, Mongolia and Russi-a, faces to Siberia area of Russia, receives direct support from the Northeast China and Bohai Sea Rim Area, and possess-es priorities in geographical location, land port infrastructure, water resources, coal resources, tourist resources andgreat potentiality in economic cooperation with Russia. The future urban function is a key port on the First Eurasia Continen-tal Bridge. Manzhouli Port will keep its first place between China and Russia land transport, and it is forecasted that thetransit amount through Manzhouli Port will go up to 10 million tons in 2005 and 20 million tons in 2010. It will be construct-ed to be a trade center of the peripheral area extending to Russia and Mongolia, a key export-oriented processing industri-al zone supported by industries such as export processing industries, export agriculture, trade services, technology trad-ing and the other service industries. It keeps being a well-known touring city for trade, shopping, sightseeing, vocation,local food, recreation and cultural events. To build Manzhouli Export Processing Industry Zone will improve city econom-ic structure, and the main sectors are organic food processing, livestock products processing, garment and furniture indus-try. Moreover, Manzhouli Export Processing Industry Zone will eventually be upgraded to be a border free trade zone.The city functional transition will inevitably affect urban spatial restructure and its expansion. The city space transforma-tion will develop as such: one development axis of No. 301 highway paralleling with Bin - Zhou(Harbin - Manzhouli) rail-way which cuts through central part of Manzhouli City, and links Zhalainuocr District with central city; three urban unitsincluding central city, Zhalainuocr District and Manzhouli Interchange Trade Zone; cohesion with Aoerjin and Cuogangpastures; regional dual-nuclei structure of Hailaer City and Manhzouli City; and the Manzhouli-Zabaykalsk Free TradeZone. 相似文献
10.
1 INTRODUCTION Blazars, including BL Lac objects, highly polarized and optically violently variable quasars,and flat-spectrum radio quasars (FSRQs), are characterized by highly variable non-thermalemission which dominates their characteristics from radio to y-ray bands. The mechanismbelieved to be responsible for their broadband emission is synchrotron radiation followed by in-verse Compton (IC) scattering at higher energies (e.g. Blandford & Konigl 1979). Relativisticbeaming of a jet… 相似文献