全文获取类型
收费全文 | 2499篇 |
免费 | 437篇 |
国内免费 | 160篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 25篇 |
2021年 | 39篇 |
2020年 | 27篇 |
2019年 | 64篇 |
2018年 | 49篇 |
2017年 | 97篇 |
2016年 | 103篇 |
2015年 | 72篇 |
2014年 | 221篇 |
2013年 | 290篇 |
2012年 | 154篇 |
2011年 | 202篇 |
2010年 | 172篇 |
2009年 | 189篇 |
2008年 | 149篇 |
2007年 | 177篇 |
2006年 | 153篇 |
2005年 | 150篇 |
2004年 | 142篇 |
2003年 | 106篇 |
2002年 | 72篇 |
2001年 | 80篇 |
2000年 | 47篇 |
1999年 | 42篇 |
1998年 | 30篇 |
1997年 | 33篇 |
1996年 | 32篇 |
1995年 | 25篇 |
1994年 | 33篇 |
1993年 | 21篇 |
1992年 | 20篇 |
1991年 | 16篇 |
1990年 | 24篇 |
1989年 | 15篇 |
1988年 | 10篇 |
1987年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有3096条查询结果,搜索用时 0 毫秒
911.
Although soft power is now seen as an indispensable foreign policy tool, its efficacy has rarely been put to a rigorous empirical test. Using data from HARMONIOUS MISSIONs 2010, 2011 and 2013, this article seeks to examine the degree to which the soft power engagement missions of the Chinese hospital ship, the Peace Ark, has advanced Chinese interests. Although any conclusions drawn must be considered preliminary, as so little time has passed between the ship's visits and the current analysis, this research indicates that these missions’ impact on advancing Chinese interests was at best limited. Although observations from a single set of cases are unlikely to settle the debate between soft power advocates and detractors, it is hoped that this research will serve as a catalyst to further empirically based research on this topic. 相似文献
912.
Yolanda Sadie 《African Security Review》2015,24(4):450-457
Commitment by the government of the Democratic Republic of Congo to addressing sexual and gender-based violence (SGBV) in the country is reflected in a number of international commitments and national strategies. This article traces the (slow) progress in addressing some of the most important issues relating to SGBV to which the government has committed itself. It argues that unless the underlying gender norms and unequal power relations that form the basis of gender violence, discrimination and inequality in Congolese society are addressed, SGBV will persist. 相似文献
913.
为揭示固体推进剂在长期贮存过程中的老化机理,解剖了自然贮存19年贴壁浇注的端羟基聚丁二烯橡胶推进剂装药发动机,沿着药柱径向不同位置进行了取样,并采用扫描电镜、能量色散X射线光谱仪、红外吸收光谱、交联密度等多种手段对这些样品进行了测试分析。研究发现:贴壁浇注发动机药柱不同位置推进剂的老化程度不尽相同,越靠近非金属壳体位置,推进剂的老化程度越严重。进一步深入分析表明:除了丁羟胶中双键的氧化断链和端羟基的缩合等影响推进剂老化,铝粉氧化产生的铝离子会催化丁羟胶双键与氯气或水发生加成反应生成■双键和仲醇,而铝离子迁移和分布的不均匀会引起药柱老化的不均匀性。研究结果对推进剂配方设计和防老化措施的研究具有重要意义。 相似文献
914.
Adrian Roads 《Arms and Armour》2017,14(2):101-137
The Pattern 1838 Musket was initially designed for the rank and file of the British army, it was instead issued to the elite Foot Guards. With arguably the lowest survival rate of any 19th Century British military firearm it is one of the rarest muskets to encounter today. This is its story … 相似文献
915.
In September 1878 the British Museum received a donation of a folded metal plate which had been embossed and gilded. Restoration of the object revealed that the folded plate was in fact the outer casing of a Roman copper alloy cavalry sports type helmet which dates to the late second or third century AD. The story of what became known as the Guisborough helmet began 14 years earlier in what was then the North Riding of Yorkshire when workers employed by the Cleveland Railway Company discovered a ‘very curious plate of metal’ during road construction. It appears that the helmet was deliberately prepared for deposition and buried at a depth of c30 cm close to a stream. Examination by the authors suggests that this was a high value item that had been repaired many times. Experimental evidence suggests that the decoration alone required approximately 16 h to fashion. 相似文献
916.
917.
918.
919.
920.