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   394篇
  免费   12篇
各国政治   23篇
工人农民   9篇
世界政治   28篇
外交国际关系   29篇
法律   210篇
中国政治   1篇
政治理论   104篇
综合类   2篇
  2023年   3篇
  2022年   1篇
  2021年   2篇
  2020年   5篇
  2019年   7篇
  2018年   20篇
  2017年   14篇
  2016年   12篇
  2015年   10篇
  2014年   14篇
  2013年   53篇
  2012年   16篇
  2011年   15篇
  2010年   16篇
  2009年   16篇
  2008年   18篇
  2007年   15篇
  2006年   16篇
  2005年   17篇
  2004年   17篇
  2003年   17篇
  2002年   9篇
  2001年   8篇
  2000年   18篇
  1999年   4篇
  1998年   4篇
  1997年   5篇
  1996年   8篇
  1995年   3篇
  1994年   3篇
  1993年   4篇
  1992年   2篇
  1991年   2篇
  1990年   4篇
  1989年   4篇
  1987年   2篇
  1986年   1篇
  1985年   3篇
  1984年   3篇
  1981年   2篇
  1980年   3篇
  1979年   3篇
  1977年   1篇
  1974年   2篇
  1973年   1篇
  1970年   2篇
  1963年   1篇
排序方式: 共有406条查询结果,搜索用时 15 毫秒
171.
172.
Nowadays, kinship studies based only on STR analysis are a very common practice. Apart from regular paternity cases, there is a rising number of cases in which the type of sibship between two persons has to be determined. Very often the parents or further relatives are unavailable for testing, so that the probability e. g. for a half-sibship has to be calculated as a deficiency situation. 50 unrelated persons (Group 1), 50 full siblings (Group 2), and 50 half-siblings (Group 3) were genotyped using the 15 STRs comprised by the AmpFlSTR Identifiler multiplex PCR-kit to investigate the reliability of common statistics programs and the indicative value of the calculated probabilities. Using a commercially available statistics program, we calculated probabilities for the following hypotheses: 1. The persons investigated are full siblings; 2. the persons investigated are half-siblings; 3. the persons investigated are unrelated. After STR analysis, half-sibling probabilities between 0.03 %-97.56% for group 1, between 0.01%-78.46% for group 2, and between 24.28%-90.18% for group 3 were calculated. In addition, the authors present two complicated deficiency cases which could be resolved only by extensive DNA typing using X- and Y-chromosomal loci, respectively, as well as the investigation of further relatives. The results of this study suggest that typing of autosomal STRs alone is no sufficient tool for resolving cases of possible half-sibship, even if probabilities of more than 90.0% are obtained. Due to the results of our study we suggest the implementation of mandatory standards for the investigation and interpretation of complicated kinship cases.  相似文献   
173.
Nowadays, more and more paternity cases are carried out investigating only child and putative father, mostly for economical or private reasons. Usually, reliable results can be obtained and the putative father can be included or ruled out with a high certainty. Considerable problems might arise when a relative of the biological father is investigated as being the putative father. In this study, we investigated 164 persons from 27 families creating artificial deficiency cases using the AmpFlSTRIdentifiler kit, which amplifies 15 STRs simultaneously. We analyzed 93 child/biological father pairs and the corresponding uncles, respectively the brothers of the biological fathers. The average paternity probability for the biological father was 99.9699% (paternity index (PI): 3321.26); only in three cases the results were under 99.9%. In five out of 125 child/uncle pairs no STR mismatches were found and paternity probabilities between 99.9726% (PI 3652) and 99.9970% (PI 33,545) were calculated. The average number of excluding loci was 3.4, but in 31.2% of the cases only zero, one or two mismatches were found. When both putative fathers were genetically typed, the biological father usually had a statistically higher paternity probability. Nevertheless, the differences between probabilities for father and uncle were only small. These results show that a reliable investigation of deficiency cases (i.e. child and putative father) seems to be more difficult than generally assumed. Especially in cases with an unknown familiar background and/or when investigating foreigners for immigration purposes, the laboratory expert should include the mother, increase the number of investigated loci or include a second method such as RFLP-analysis, some serological systems or typing of X-chromosome specific STRs to further ascertain the results.  相似文献   
174.
A capillary zone electrophoresis (CZE) method was developed for the analysis of amphetamine and 13 amphetamine analogues. A full factorial design was used to screen for important design variables (i.e. carrier electrolyte concentration, pH, and separation temperature), and a modified simplex was employed in a final optimisation step. The resolution values of the target compounds were used as responses in the screening and optimisation phases. This approach made it possible to control the effects of the design variables on the separation of the target compounds. The best results were obtained using a 100mM Tris/phosphate buffer (pH 3.1) at a separation temperature of 10 degrees C, and the analysis time was 23 min under these conditions. After slight modification, the method also enabled baseline resolution of the most commonly encountered amphetamine derivatives, as well as cocaine and heroin, within 7 min. There was a linear relationship between peak area and concentration for all substances, with correlation coefficients in the range of 0.9975-0.9999. Moreover, the technique was repeatable and exhibited relative standard deviation (R.S.D.) values in the ranges of 0.01-0.11% and 0.54-1.60% for relative migration time and corrected peak area, respectively. Lastly, the method was successfully applied to analyse street samples.  相似文献   
175.
Some numbers in the political sphere seem to be chosen rather arbitrarily. One example might be the rule set out by the Second Senate of the German Federal Constitutional Court in 1995 that the overall tax load on assets must be limited to 50% of the yield on those assets. This rule was understood by many as a general principle for taxation. The article first sketches the socio-political climate under which the rule originated: a rise of neo-liberal thought met with the inability of the political institutions to reform the German welfare state with its ever-growing expenses. The Constitutional Court’s intervention is interpreted as a reaction to this stagnation in politics. An analysis from the perspective of Constitutional Law, however, reveals that the 50% rule cannot be convincingly based on the German Basic Law, and instead must be seen as a political move of the Court. But this move did not follow an economic rationality, either; for an optimal government’s share can only be determined in relation to the economic performance of a country and not by fixing it generally at a maximum of 50% of GDP. The demise of the 50% rule already began four years later. In 2006, finally, the Senate moved away from the individual rights-based approach of 1995 to a more general assessment, taking also into account an increasingly globalized tax competition. The reason for this clear-cut change in the Court’s jurisprudence can be found in a change of the socio-political and institutional parameters, thus witnessing to the effect of the political climate on court decisions. The analysis also shows that the rule was created and abandoned only on the basis of an “introverted” legal discussion, economic arguments hardly playing any role in the process. The new line of the Senate, however, might guarantee for a better integration of economic science into tax policy by exchanging fixed limits for a “discursive” model, demanding from the tax legislator better reasons for higher taxes.  相似文献   
176.
177.
What determines public health care expenditures at the national level is an important policy question. Since the pioneering work of Newhouse (J Hum Resour 12(1):115–125, 1977) on the relationship between health expenditures and national income, this area of economic inquiry has received much attention. This paper seeks an answer to this question by estimating the factors affecting public health expenditures at the national level in Pakistan. This paper uses annual time series data from 1972 to 2009 and employing unit root and Johansen cointegration methods estimated the determinants of public health expenditures. It is estimated that all variables are integrated of order one and are cointegrated hence in a long run relationship. The income elasticity of public health care expenditures is estimated below unity (at 0.26) indicating health care is a necessity in Pakistan contrary to most of the industrialized countries. Furthermore, it is imperative that government have a larger role in allocating and directing public resources to health care in Pakistan. Urbanization and unemployment variables have elasticity values of ?1.33 and ?0.37 respectively, implying that it is costly to provide health care to residents of remote rural areas of Pakistan.  相似文献   
178.
History offers valuable lessons to housing policymakers. For those who would devise new low-income housing programs during today's trying economic circumstances, it is helpful to study the strategies that succeeded in achieving low-income housing programs in past difficult times. This article, History Lessons for Today's Housing Policy, examines the political processes that led to the adoption of new low-income housing policies during four political crises. The four crises were the Great Depression of the 1930s, the post-World War II housing shortage, the urban crisis of the 1960s, and the policy crisis of the 1970s. Among other history lessons, the article reveals that well-organized political support, especially from large institutions, is crucial to achieving distinctly different new programs; that decentralized programs are more politically resilient than centralized programs; that programs that appeal to the nation's broad middle-class are most popular; and that policy research is valuable but that politics trumps research.  相似文献   
179.
The German political economy has often been cited as a classical case of non-shareholder value orientation. Its productionist, long-term, consensus orientation has often been contrasted with the 'Anglo-Saxon approach'. The influence of shareholders who press for shareholder value and the importance of the equity market have traditionally been low. But there are signs of change. In this article we describe some of these changes and try to assess the dynamics of this change process. First we show that the limited role of the equity market for company financing and for private household savings still provides a very narrow base for a shareholder value economy in Germany. The central pillars of the German system of corporate governance - the dominating role of banks, the system of co-determination and the company centred management system - are not crumbling. Change in the direction of shareholder value is therefore limited.  相似文献   
180.
The likelihood that longevity will continue to increase has generated a search for regulation that make people work longer as they live longer, and thus not just containing pension expenditure but also enlarging labor supply, economic growth, and tax revenue. In public pension policy, Nordic countries have led the world with three types of approaches aimed at making people retire later. The first came when Sweden, followed by Finland and Norway, installed life expectancy coefficients in benefit calculation formulas. The second followed as Finland introduced age-related accrual rates and the third when Denmark indexed the pensionable age to developments in life expectancy. Since economic incentive-based regulations failed to raise exit ages sufficiently, Finland and Sweden subsequently linked pensionable ages to life expectancy like Denmark. While this policy brings out inequalities in health and workability, the fact that countries found it necessary to index the pensionable age to longevity instead of just relying on economic incentives in regulating retirement behavior may hold lessons for other countries.  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