全文获取类型
收费全文 | 7259篇 |
免费 | 301篇 |
专业分类
各国政治 | 492篇 |
工人农民 | 237篇 |
世界政治 | 704篇 |
外交国际关系 | 540篇 |
法律 | 3197篇 |
中国政治 | 60篇 |
政治理论 | 2249篇 |
综合类 | 81篇 |
出版年
2023年 | 59篇 |
2022年 | 42篇 |
2021年 | 67篇 |
2020年 | 138篇 |
2019年 | 194篇 |
2018年 | 209篇 |
2017年 | 250篇 |
2016年 | 262篇 |
2015年 | 151篇 |
2014年 | 223篇 |
2013年 | 1188篇 |
2012年 | 224篇 |
2011年 | 213篇 |
2010年 | 211篇 |
2009年 | 218篇 |
2008年 | 201篇 |
2007年 | 278篇 |
2006年 | 234篇 |
2005年 | 275篇 |
2004年 | 263篇 |
2003年 | 242篇 |
2002年 | 267篇 |
2001年 | 139篇 |
2000年 | 133篇 |
1999年 | 120篇 |
1998年 | 102篇 |
1997年 | 101篇 |
1996年 | 96篇 |
1995年 | 105篇 |
1994年 | 102篇 |
1993年 | 81篇 |
1992年 | 103篇 |
1991年 | 98篇 |
1990年 | 68篇 |
1989年 | 75篇 |
1988年 | 72篇 |
1987年 | 69篇 |
1986年 | 74篇 |
1985年 | 68篇 |
1984年 | 56篇 |
1983年 | 69篇 |
1982年 | 52篇 |
1981年 | 57篇 |
1980年 | 42篇 |
1979年 | 37篇 |
1978年 | 32篇 |
1977年 | 34篇 |
1976年 | 31篇 |
1975年 | 17篇 |
1973年 | 16篇 |
排序方式: 共有7560条查询结果,搜索用时 46 毫秒
71.
David Popenoe 《Society》1993,30(6):5-11
He is co-author of Fatherless America,which is forthcoming. He serves as co-chair of the Council on Families in America, a nonpartisan, interdisciplinary group
of scholars and family experts concerned with family and child well-being. 相似文献
72.
73.
74.
Little literature has been developed to describe the process of transferring a corporation's technology between international
units of that company for ultimate transfer to their external customers (Kimberly 1981 and Leonard-Barton and Sinha 1993).
This paper addresses the issues at Air Products and Chemicals, Inc. involved in the transfer of applications technology. Technology
is transferred from the unit of the corporation which develops the technology to international affiliates and subsidiaries.
The ultimate goal is the support of product sales to the external industrial customer. A strategy for this type of organization
is described which is supported by references to theoretical constructs in the literature and empirical observations from
the organization itself. 相似文献
75.
76.
77.
78.
79.
David Scott 《Asia-Pacific Review》2006,13(2):97-129
This article considers how India sees the Indian Ocean, and in particular its drive to make the Indian Ocean, “India's Ocean.” Various comparisons and links are made. Firstly there is the role and application of Mahanian tenets of “sea-power,” in particular naval projection, control of sea-routes and access to bases. Second is the contrast between the earlier maritime visions of Kavalam Panikkar (1945) and Keshav Vaidya (1949) and the continental mindset evident under Nehru and his successors which saw neglect of India's maritime power. Third is the strategic vision evident since 1998 with the BJP government and maintained by the Congress administration since 2004. This has underpinned India's Naval Chief of Staff Arun Prakash's current eloquence on the possibilities opening up for India in and around the Indian Ocean. Questions of intent (strategic doctrine) and the application of “state power” (spending, bases, ships and equipment, geographical reach) are woven together. 相似文献
80.
Marta Concheiro Ana de Castro Oscar Quintela Manuel Lpez-Rivadulla Angelines Cruz 《Forensic Science International Supplement Series》2005,150(2-3):221
This paper describes the analytical methodology for the determination of MDMA, MDA, MDEA and MBDB in oral fluid. After a liquid–liquid extraction, the analysis was carried out by high performance liquid chromatography (HPLC), with fluorescence detection. The detector wavelength was fixed at 285 nm for excitation and 320 nm for emission. The mobile phase, a mixture of phosphate buffer (pH = 5) and acetonitrile (75:25), and the column, Kromasil 100 C8 5 μm 250 mm × 4.6 mm, allowed good separation of the compounds in an isocratic mode in only 10 min. The method was validated and showed good limits of detection (2 ng/mL) and quantitation (10 ng/mL) for all the amphetamine derivatives. No interfering substances were detected. A stability study of these compounds in oral fluid stored at three different temperatures (−18, 4 and 20 °C) over 10 weeks was conducted, showing a time-dependent degradation of the four compounds. 相似文献