全文获取类型
收费全文 | 1158篇 |
免费 | 65篇 |
专业分类
各国政治 | 73篇 |
工人农民 | 62篇 |
世界政治 | 97篇 |
外交国际关系 | 71篇 |
法律 | 551篇 |
中国政治 | 8篇 |
政治理论 | 349篇 |
综合类 | 12篇 |
出版年
2023年 | 6篇 |
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 17篇 |
2019年 | 27篇 |
2018年 | 43篇 |
2017年 | 48篇 |
2016年 | 48篇 |
2015年 | 37篇 |
2014年 | 41篇 |
2013年 | 185篇 |
2012年 | 38篇 |
2011年 | 45篇 |
2010年 | 33篇 |
2009年 | 40篇 |
2008年 | 47篇 |
2007年 | 48篇 |
2006年 | 50篇 |
2005年 | 39篇 |
2004年 | 29篇 |
2003年 | 41篇 |
2002年 | 28篇 |
2001年 | 18篇 |
2000年 | 26篇 |
1999年 | 16篇 |
1998年 | 16篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 13篇 |
1991年 | 15篇 |
1990年 | 15篇 |
1989年 | 15篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 14篇 |
1985年 | 20篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 13篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 4篇 |
1976年 | 3篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1968年 | 3篇 |
1965年 | 4篇 |
排序方式: 共有1223条查询结果,搜索用时 15 毫秒
281.
Chadwick S Maynard P Kirkbride P Lennard C Spindler X Roux C 《Journal of forensic sciences》2011,56(6):1505-1513
In current casework, most post-cyanoacrylate stains rely on luminescence emission in the visible region (400-700 nm). While traditional stains such as rhodamine 6G work well under most circumstances, some surfaces may generate background luminescence under the same conditions. Detection in the near-infrared region (NIR > 700 nm) has shown to be effective in minimizing the interferences from such surfaces. The laser dye styryl 11 generated strongly luminescent fingermarks when applied after cyanoacrylate fuming on all surfaces tested. When compared to rhodamine 6G, the dye was superior only when viewed in the NIR. Styryl 11 was subsequently combined with rhodamine 6G, and the mixed stain formulation (named StaR 11 by the authors) induced stronger luminescence compared with styryl 11 alone with an ability to visualize in both the visible and NIR regions. Reliable and consistent results were obtained when using either styryl 11 alone or the STaR 11 mixture. The enhancement achieved did not otherwise vary depending on the source of the fingermark secretions. With visualization possible in both the visible and NIR regions, the styryl 11/rhodamine 6G mixture showed significant potential as a post-cyanoacrylate stain. 相似文献
282.
Violence is a critical cause of death and nonfatal injuries among youth, and even those who witness violence can suffer serious health and mental health consequences. This highlights the need for prevention programs and policies aimed at reducing risks, promoting prosocial behavior, strengthening families, and creating communities in which youth are safe from violence. The Centers for Disease Control and Prevention's Injury Center is developing a National Public Health Strategy to Prevent Youth Violence. The strategy will establish a full application of the public health approach, ranging from research to practice. It also spotlights what is working, as a way to mobilize community leaders in supporting evidence-based initiatives. With the empirical guidance of articles such as those in this special issue, a shared strategy to prevent youth violence will help focus efforts and resources on solutions that show the most promise, and ensure that American communities undertake more comprehensive and coordinated prevention efforts to protect our nation's youth. 相似文献
283.
Crosson S 《Politics and the life sciences》2011,30(2):31-42
Research in recent decades has shown that although conventional fisheries management strategies such as fishing seasons, size limits, or gear restrictions can provide sufficient biological protection to fisheries stocks, they do not necessarily lead to satisfactory social or economic outcomes. In their stead, the merits and shortcomings of a variety of alternate management systems, including individual transferable quotas, have been proposed, implemented, and analyzed. Few investigations, however, have examined actual fishers' preferences for different management systems. Integrating results from a mail survey of North Carolina commercial fishers with their individual harvest histories and sociodemographic profiles shows that economic and cultural variables both play a significant role in management system preference. The analysis introduces the use of the Herfindahl-Hirschman Index (HHI), a measure of investment diversity, as a measure of diversity in fisheries harvests and demonstrates an association with management preferences. Social and family factors are also notable indicators. 相似文献
284.
285.
Jeffrey L. Furman Fiona Murray Scott Stern 《Journal of policy analysis and management》2012,31(3):661-705
This paper articulates a citation‐based approach to science policy evaluation and employs that approach to investigate the impact of the United States’ 2001 policy regarding the federal funding of human embryonic stem cell (hESC) research. We evaluate the impact of the policy on the level of U.S. hESC research, the U.S. position at the knowledge frontier, and the strategic response of U.S. scientists. Consistent with recent research on the science of science and innovation policy, we employ a difference‐in‐differences approach using bibliometric data with the aim of analyzing the causal impact of the policy on cumulative research. Our estimates suggest that in the aftermath of the 2001 policy, U.S. production of hESC research lagged 35 to 40 percent behind anticipated levels. However, this relative decline was largely concentrated in the years 2001 to 2003 and ameliorated over time. The rebound in U.S. hESC research after 2003 was driven by contributions by researchers at elite U.S. institutions and U.S. researchers who collaborated with international partners. The results suggest that scientists respond strategically to research funding restrictions and that modest science policy shifts can have a significant influence on the within‐country composition of research and the pattern of global research collaboration. 相似文献
286.
This article examines the origins and main strands of recent debates within the international development community regarding the tensions between increasing aid allocation to so-called ??fragile states?? and growing domestic and international pressure for donors to demonstrate measurable results and returns on their investments. With particular reference to the UK context, the paper examines how the confluence of these two agendas is being viewed, at least publicly, and some of the main arguments that have been put forward about why they may be difficult to pursue simultaneously. It asks whether or not it is feasible that donors will explicitly seek to address and resolve the apparent trade-offs between these two agendas, and concludes that in both international and domestic political arenas, ??good enough?? aid effectiveness, or a more nuanced, ??developmentised?? understanding of value for money, are unlikely to become palatable or politically viable any time soon. 相似文献
287.
Medical technology has made tremendous strides in extending the lives of patients who have suffered organ failure. Machines can now replace the function of the kidneys, the heart, and other vital organs. Much has been written about a patient's right to refuse or direct the withdrawal of medical treatment, especially at the end of life, under the guise of “death with dignity.” However, little attention has been paid to the situation where a patient elects to deactivate their life-sustaining medical device without a physician's involvement. This raises the challenging question of whether the patient's manner of death should be classified as suicide or natural. Surprisingly, common law, statutes, medical ethics, and public health practice are not in alignment on the answer. This article will explore the ramifications and far-reaching impact that such divergence has on the survivors and the medical community, as well as recommend corrective actions and practical approaches for the medical and legal practitioner. 相似文献
288.
Scott R. Pearson 《发展研究杂志》2013,49(4):320-333
Net social profitability (NSP) and domestic resource costs of foreign exchange earned or saved (DRC) are conceptually related, since each can be derived from the other. The effective rate of protection on value added (ERP) is algebraically identical to DRC if all importable inputs are actually imported or are zero, NSP is zero, and (ERP+1) is multiplied by the shadow price of foreign exchange. A decision rule for allocation of resources is to approve all projects with a positive NSP and a DRC ratio less than the shadow price of foreign exchange. No comparable rule can be stated for ERP, except under special assumptions. 相似文献
289.
Scott Cook 《发展研究杂志》2013,49(4):442-445
Social Relations in a Philippine Market: Self‐interest and Subjectivity by William G. Davis. Berkeley, Los Angeles, London: University of California Press, 1973. Pp. xiii+315, maps, tables; $12.50. 相似文献
290.