首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   328篇
  免费   11篇
各国政治   43篇
工人农民   22篇
世界政治   32篇
外交国际关系   17篇
法律   130篇
中国政治   3篇
政治理论   87篇
综合类   5篇
  2021年   2篇
  2020年   11篇
  2019年   9篇
  2018年   8篇
  2017年   10篇
  2016年   8篇
  2015年   12篇
  2014年   5篇
  2013年   67篇
  2012年   8篇
  2011年   11篇
  2010年   10篇
  2009年   6篇
  2008年   10篇
  2007年   9篇
  2006年   8篇
  2005年   8篇
  2004年   8篇
  2003年   12篇
  2002年   6篇
  2001年   11篇
  2000年   5篇
  1999年   10篇
  1998年   7篇
  1997年   3篇
  1996年   8篇
  1995年   4篇
  1994年   6篇
  1993年   3篇
  1992年   4篇
  1991年   7篇
  1990年   2篇
  1989年   2篇
  1988年   4篇
  1987年   3篇
  1986年   1篇
  1985年   1篇
  1984年   4篇
  1983年   3篇
  1981年   3篇
  1980年   4篇
  1978年   2篇
  1977年   2篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
  1972年   4篇
  1971年   1篇
  1969年   1篇
  1966年   1篇
排序方式: 共有339条查询结果,搜索用时 15 毫秒
331.
332.
To be presented at the 1982 Annual Meetings of Canadian Sociology and Anthropology Association in Ottawa, June 6–9. The author would like to thank the many people working with juveniles in Alberta and elsewhere who provided insights for this paper. The work has been supported by the Social Sciences and Humanities Research Council of Canada, Grant Sumber 410-79-0124 and by funds from the Solicitor General's Contributions Grant.  相似文献   
333.
The effects of age of witness, gender of witness, lineup presentation, and practice on eyewitness testimony were investigated. Ninety-six elementary-school children and 96 college students viewed a slide sequence of a crime, followed by target-present or target-absent photo identification in sequentially or simultaneously presented lineups. Prior to photo identification, half the subjects received a practice lineup. Children had a higher rate of choosing than adults, resulting in more foil identification errors in both target-present and target-absent lineups. Without prior practice, sequential presentation as compared to simultaneous presentation reduced errors in target-absent lineups for adult witnesses and showed a similar but nonsignificant reduction for child witnesses. With prior practice, sequential presentation lost the advantage over simultaneous presentation in target-absent error reduction. Practice reduced target-absent errors in simultaneous-presentation lineups for both age groups.  相似文献   
334.
Parental choice and operational efficiency are the key features proponents use to promote the desirability of educational voucher programs. The argument is that educational vouchers increase competition among schools by allowing parents the freedom to choose which schools their children attend. In turn, competition improves the performance of individual schools. This article argues that, as currently put forth, the case for vouchers minimizes the special position of public schools with respect to their equity goals. Equity, arguably, has been one of the most significant tenets of public education policy in the last half-century. Moreover, vouchers have significant hidden costs that could compromise any efficiency.  相似文献   
335.
336.
The inherent cross-border nature of the internet has challenged the legal system for over two decades. In this paper we introduce a model in which the internet is approached as if it were the high seas, the harbor of origin, the harbor of destination, or a combination of these. This model is used to rephrase existing case law related to internet jurisdiction from an international law perspective, the US and the EU (in particular Germany and the Netherlands). The model helps to illuminate the positions taken by the parties and the judge, and to indicate possible alternative interpretations. In some cases a high seas approach would have made sense (Yahoo!), or more recently the Vacation Rental by Owner case about trademarks where registration in one country was deemed to have an effect everywhere a person had the trademark on his or her computer screen. In H&M v G-star the Dutch Supreme Court even established jurisdiction based on an infringing product that was not available in the city of the court but was to become available on the internet some time in the future. We do not take a position in this paper on what perspective, based on our model, is best, but make clear how to identify the possible arguments.  相似文献   
337.
Nonbiting midges (Diptera, Chironomidae) are the most abundant members of the fauna associated with submerged carcasses, but their use in the medicolegal context is very restricted because of their complex ontogeny. In this case, the corpse of a woman was recovered in late spring from a river in Granada (Iberian Peninsula). It showed obvious signs of long permanence in the aquatic environment and, along with pulmonary and microscopical analyses, led to the conclusion that the cause of death was drowning. Several larvae‐like specimens were sampled from the scalp and later identified by morphological external features as IV instar larvae of Chironomus riparius Meigen, 1804 (Diptera, Chironomidae). Sequencing of cytochrome oxidase subunit I was performed to confirm the identification. The knowledge of the biology of C. riparius at low temperatures was critical to assess a postsubmersion interval of 16–17 days.  相似文献   
338.
Both target effectiveness and administrative simplicity are desirable properties in the design of minimum benefit packages for public retirement programs. The federal benefit rate (FBR) of the Supplemental Security Income (SSI) program has been proposed by some analysts as a potentially attractive basis of establishing a new minimum benefit for Social Security on both of these grounds. This type of proposal is related to a broader array of minimum benefit proposals that would establish a Social Security benefit floor based on the poverty rate. In contrast to Social Security, the SSI program is means tested, including both an income and asset screen and also a categorical eligibility screen (the requirement to qualify as aged or disabled). The SSI FBR provides an inflation-adjusted, guaranteed income floor for aged and disabled people with low assets. The FBR has been perceived by proponents as a minimal measure of Social Security benefit adequacy because it represents a subpoverty income level for a family of one or two depending on marital status. For this same reason it has been seen as a target-effective tool of designing a minimum Social Security benefit. An FBR-based minimum benefit has also been viewed as administratively simple to implement; the benefit can be calculated from Social Security administrative records using a completely automated electronic process. Therefore-in contrast to the SSI program itself-an FBR-based minimum benefit would incur virtually no ongoing administrative costs, would not require a separate application for a means-tested program, and would avoid the perception of welfare stigma. While these ideas have been discussed in the literature and among policymakers in the United States over the years, and similar proposals have been considered or implemented in several foreign countries, there have been no previous analyses measuring the size of the potentially affected beneficiary population. Nor has there been any systematic assessment of the FBR as a measure of benefit adequacy or the tradeoffs between potential target effectiveness and administrative simplicity. Based on a series of simulations, we assess the FBR as a potential foundation for minimum Social Security benefits and we examine the tradeoffs between administrative simplicity and target effectiveness using microdata from the 1996 panel of the Survey of Income and Program Participation (SIPP). Our empirical analysis is limited to Social Security retired-worker beneficiaries aged 65 or older. We start with the assessment of the FBR as a measure of benefit adequacy. We are particularly concerned about two types of error: (1) incorrectly identifying some Social Security beneficiaries as "economically vulnerable," and (2) incorrectly identifying others as "not economically vulnerable." Operationally we measure economic vulnerability by two alternative standards. One of our measures considers beneficiaries with family income below the official poverty threshold as vulnerable. Our second measure is more restrictive; it uses a family income threshold equal to 75 percent of the official poverty threshold. We find that a substantial minority of retired workers have Social Security benefits below the FBR. The results also show that the FBR-based measure of Social Security benefit adequacy is very imprecise in terms of identifying economically vulnerable people. We estimate that the vast majority of beneficiaries with Social Security benefits below the FBR are not economically vulnerable. Conversely, an FBR-level Social Security benefit threshold fails to identify some beneficiaries who are economically vulnerable. Thus an FBR-level minimum benefit would be poorly targeted in terms of both types of errors we are concerned about. An FBR-level minimum benefit would provide minimum Social Security benefits to many people who are clearly not poor. Conversely, an FBR-level minimum benefit would not provide any income relief to some who are poor. The administrative simplicity behind these screening errors also results in additional program cost that may be perceived as substantial. We estimate that an FBR-level minimum benefit would increase aggregate program cost for retired workers aged 65 or older by roughly 2 percent. There are two fundamental reasons for these findings. First, the concept of an FBR-level minimum benefit looks at the individual or married couple in artificial isolation; however, the family is the main consumption unit in our society. The income of an unmarried partner or family members other than a married spouse is ignored. Second, individuals and couples may also have income from sources other than Social Security or SSI, which is also ignored by a simple FBR-based minimum benefit concept. The substantial empirical magnitude of measurement error arising from these conceptual simplifications naturally leads to the assessment of the tradeoff between target effectiveness and administrative simplicity. To facilitate this analysis, we simulate the potential effect of alternative screening methods designed to increase target effectiveness; while reducing program cost, such alternatives also may increase administrative complexity. For example, considering the combined Social Security benefit of a married couple (rather than looking at the husband and wife in isolation) might substantially increase target effectiveness with a relatively small increase in administrative complexity. Adding a family income screen might increase administrative complexity to a greater degree, but also would increase target effectiveness dramatically. The results also suggest that at some point adding new screens-such as a comprehensive asset test-may drastically increase administrative complexity with diminishing returns in terms of increased target effectiveness and reduced program cost. Whether a broad-based minimum benefit concept that is not tied to previous work experience is perceived by policymakers as desirable or not may depend on several factors not addressed in this article. However, to the extent that this type of minimum benefit design is regarded as potentially desirable, the tradeoffs between administrative simplicity and target effectiveness need to be considered.  相似文献   
339.
This study consisted of three parts to evaluate the performance of Lumicyano? on a variety of fabrics. One part assessed the impact of dye percentage (8%, 9% and 10%) on visualisation of fingermark detail and luminescent brightness in split grab marks. A 9% dye produced the highest quality detail of grab impressions with least interference from background fluorescence. The second part investigated the optimal relative humidity (RH, 75–84%) for certain fabric types using Lumicyano on split, six-series depletion fingermarks. It was concluded that the recommended RH of 80% remained the ideal cyanoacrylate fuming environment. The final and third part of this study determined the impact of sequential addition of Basic Yellow 40 (BY40) on Lumicyano compared to traditional cyanoacrylate (CA) followed with BY40 application. Results from this study demonstrated that Lumicyano on its own developed fingermarks with superior quality to Lumicyano with sequential addition of BY40 or traditional cyanoacrylate followed by BY40. Inclusion of more fabrics, donors and longer ageing periods should be explored in future studies to determine what frameworks are best for certain types of fabrics.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号