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   386篇
  免费   12篇
各国政治   13篇
工人农民   13篇
世界政治   45篇
外交国际关系   15篇
法律   198篇
中国政治   2篇
政治理论   105篇
综合类   7篇
  2023年   2篇
  2022年   1篇
  2021年   2篇
  2020年   4篇
  2019年   13篇
  2018年   16篇
  2017年   8篇
  2016年   11篇
  2015年   9篇
  2014年   14篇
  2013年   74篇
  2012年   12篇
  2011年   18篇
  2010年   12篇
  2009年   6篇
  2008年   12篇
  2007年   16篇
  2006年   17篇
  2005年   11篇
  2004年   12篇
  2003年   14篇
  2002年   13篇
  2001年   7篇
  2000年   6篇
  1999年   11篇
  1998年   5篇
  1997年   3篇
  1996年   8篇
  1995年   3篇
  1994年   7篇
  1993年   4篇
  1992年   5篇
  1991年   4篇
  1990年   3篇
  1989年   2篇
  1988年   6篇
  1987年   2篇
  1986年   2篇
  1985年   5篇
  1984年   2篇
  1982年   1篇
  1981年   1篇
  1979年   2篇
  1978年   2篇
  1976年   1篇
  1975年   4篇
  1972年   1篇
  1971年   1篇
  1969年   2篇
  1968年   1篇
排序方式: 共有398条查询结果,搜索用时 15 毫秒
111.
112.
Laser-induced detection of fluorescent labeled PCR products and multi-wavelength detection (i.e., multicolor analysis) enables rapid generation of mtDNA sequencing profiles. Traditionally, polyacrylamide slab gels have been used as the electrophoretic medium for mtDNA sequencing in forensic analyses. Replacement of slab gel electrophoresis with capillary electrophoresis (CE) can facilitate automation of the analytical process. Automation and high throughput can be further enhanced by using multicapillary electrophoretic systems. The use of the ABI Prism 3100 Genetic Analyzer (ABI 3100, Applied Biosystems, Foster City, CA) as well as the ABI Prism 310 Genetic Analyzer (ABI 310, Applied Biosystems, Foster City, CA) were evaluated for mtDNA sequencing capabilities and compared with sequencing results obtained on the platform currently in use in the FBI Laboratory (the ABI Prism 377 DNA Sequencer, ABI 377, Applied Biosystems, Foster City, CA). Various studies were performed to assess the utility of the ABI 3100, as well as the ABI 310 for mtDNA sequencing. The tests included: comparisons of results obtained among the ABI 3100, the ABI 310 and the ABI 377 instruments; comparisons of results obtained within and between capillary arrays; evaluation of capillary length; evaluation of sample injection time; evaluation of the resolution of mixtures/heteroplasmic samples; and evaluation of the sensitivity of detection of a minor component with reduced template on the ABI 3100. In addition, other studies were performed to improve sample preparation; these included: comparison of template suppression reagent (TSR, Applied Biosystems, Foster City, CA) versus formamide; the use of Performa DTR Gel Filtration Cartridges (Edge BioSystems Inc., Gaithersburg, MD) versus Centri-Sep Spin Columns (Princeton Separations, Adelphia, NJ) for product purification after cycle sequencing; and sample stability after denaturation. The data support that valid and reliable results can be obtained using either capillary electrophoresis instrument, and the quality of sequencing results are comparable to or better than those obtained from the ABI 377 instrument.  相似文献   
113.
The application of supercritical fluid chromatography (SFC) in forensic science is reviewed. The applications centre on the analysis of explosives and of drugs of abuse. The systems employed are discussed in the context of comparison with gas chromatography and high-performance liquid chromatography methods which are traditionally used for such analyses. The advantages and disadvantages of SFC over these methods are discussed. Recommendations are made for the developments which are required in SFC technology if it is to find greater application in forensic science.  相似文献   
114.
Economic Change and Restructuring - Two recent studies of SME share determination have employed a partial adjustment model which specifies disequilibrium as the sole means of explanation....  相似文献   
115.
The authors draw on experience from Uganda's commitment to decentralisation. This commitment is transforming the way services are planned and financed; new associations between local governments, NGOs, and private sector agencies are being created. Much attention has focused on the adoption of various techniques-such as participatory rural appraisal-through which direct and intensive forms of participation can be encouraged in decentralised planning. This trend is critically examined and potential unintended consequences are highlighted. A broader concept of accountability is outlined to illustrate a more inclusive approach to planning and allocation for more equity and sustainability in rural services.  相似文献   
116.
The possibility that homicides can spread from one geographic area toanother has been entertained for some time by social scientists, yetsystematic efforts to demonstrate the existence, or estimate the strength,of such a diffusion process are just beginning. This paper uses exploratoryspatial data analysis (ESDA) to examine the distribution of homicides in 78counties in, or around, the St. Louis metropolitan area for two timeperiods: a period of relatively stable homicide (1984–1988) and aperiod of generally increasing homicide (1988–1993). The findingsreveal that homicides are distributed nonrandomly, suggestive of positivespatial autocorrelation. Moreover, changes over time in the distribution ofhomicides suggest the possible diffusion of lethal violence out of onecounty containing a medium-sized city (Macon County) into two nearbycounties (Morgan and Sangamon Counties) located to the west. Althoughtraditional correlates of homicide do not account for its nonrandom spatialdistribution across counties, we find some evidence that more affluentareas, or those more rural or agricultural areas, serve as barriers againstthe diffusion of homicides. The patterns of spatial distribution revealedthrough ESDA provide an empirical foundation for the specification ofmultivariate models which can provide formal tests for diffusion processes.  相似文献   
117.
The implications of different potential affirmative action policies depend on three factors: selection rate from the applicant pool, base rate of qualified applicants, and accuracy of performance predictions. A series of analyses was conducted under various assumptions concerning affirmative action plans, causes of racial differences in average college admissions test scores, and racial differences in accuracy of performance predictions. Evidence suggesting a lower level of predictive accuracy for African Americans implies that, under a program of affirmative action, both proportionately more false positives (matriculated students who do not succeed) and proportionately more false negatives (rejected applicants who could have succeeded) will be found among African American applicants. Unless equivalent levels of predictive accuracy are achieved for both groups, no admission policy can be fair simultaneously to majority group applicants and African American applicants. © 2002 by the Association for Public Policy Analysis and Management.  相似文献   
118.
Stewart  Ian 《Publius》1990,20(1):99-112
The boundary that separates the Canadian provinces of New Brunswickand Nova Scotia was established in 1784. This article contraststhe political orientations of those who live within a commonborder region, but on opposite sides of the New Brunswick andNova Scotia boundary, and concludes that the boundary line hasindependently had a divisive impact on the area's politicalculture. Unless this particular provincial boundary is atypical,therefore, the institution of federalism is, in some measure,inherently centrifugal.  相似文献   
119.
The effect of interpersonal environment, as measured by the degree of heterogeneity or homogeneity of political party preferences among important others in an individual's social network, was investigated using a national probability sample in Japan and regional sample in New Zealand. In both cultures, the interpersonal environment exerted significant and consistent effects on individual voting preferences. Those who reported inhabiting relatively homogeneous interpersonal political environments (IPEs) displayed a strong tendency to vote for the same political party as the important others in their social network. This effect was robust even after controlling for party identification, attitudes, media exposure, and objectively defined group memberships. Importantly, this tendency was not predicated on the frequency of talk about politics with significant others. Implications are discussed for both micro-level and macro-level theories of social structure and political behavior; an argument is made for the importance of a middle path—the psychology of enduring relationships between people.  相似文献   
120.
Moskos MA  Achilles J  Gray D 《危机》2004,25(4):176-182
In the United States, teen suicide rates tripled over several decades, but have declined slightly since the mid-1990s. Suicide, by its nature, is a complex problem. Many myths have developed about individuals who complete suicide, suicide risk factors, current prevention programs, and the treatment of at-risk youth. The purpose of this article is to address these myths, to separate fact from fiction, and offer recommendations for future suicide prevention programs. Myth #1: Suicide attempters and completers are similar Myth #2: Current prevention programs work. Myth #3: Teenagers have the highest suicide rate. Myth #4: Suicide is caused by family and social stress. Myth #5: Suicide is not inherited genetically. Myth #6: Teen suicide represents treatment failure. Psychiatric illnesses are often viewed differently from other medical problems. Research should precede any public health effort, so that suicide prevention programs can be designed, implemented, and evaluated appropriately. Too often suicide prevention programs do not use evidence-based research or practice methodologies. More funding is warranted to continue evidence-based studies. We propose that suicide be studied like any medical illness, and that future prevention efforts are evidence-based, with appropriate outcome measures.  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