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   6866篇
  免费   318篇
各国政治   391篇
工人农民   316篇
世界政治   626篇
外交国际关系   348篇
法律   4263篇
中国政治   41篇
政治理论   1169篇
综合类   30篇
  2023年   63篇
  2022年   49篇
  2021年   92篇
  2020年   170篇
  2019年   187篇
  2018年   256篇
  2017年   294篇
  2016年   268篇
  2015年   194篇
  2014年   250篇
  2013年   813篇
  2012年   239篇
  2011年   235篇
  2010年   159篇
  2009年   149篇
  2008年   211篇
  2007年   199篇
  2006年   194篇
  2005年   167篇
  2004年   193篇
  2003年   167篇
  2002年   139篇
  2001年   237篇
  2000年   195篇
  1999年   136篇
  1998年   63篇
  1997年   63篇
  1996年   48篇
  1995年   66篇
  1994年   62篇
  1993年   70篇
  1992年   97篇
  1991年   101篇
  1990年   90篇
  1989年   73篇
  1988年   92篇
  1987年   91篇
  1986年   105篇
  1985年   114篇
  1984年   96篇
  1983年   83篇
  1982年   44篇
  1981年   38篇
  1979年   44篇
  1978年   37篇
  1974年   52篇
  1973年   37篇
  1972年   35篇
  1971年   38篇
  1970年   36篇
排序方式: 共有7184条查询结果,搜索用时 15 毫秒
921.
Haplotype frequencies for 11 Y-STR markers (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438 and DYS439) in a Romani population (n=63) from Slovakia, Jats of Haryana (n=84) and Jat Sikhs (n=80) from India were determined. The Slovakian Romani, the Haryana and Sikh populations were endogamous based on their unique haplotype ratio and haplotype diversity values, although the Sikh population appeared to be more diverse. AMOVA revealed non-significant differences between the Romanies and significant differences with non-Romani populations. The Macedonian Romani population differed from all Romani populations examined. Frequent haplotypes observed in Romani populations were sporadic in northwest Indian populations. Thirteen out of 316 populations worldwide were found to share the six most frequent haplotypes of the Slovakian Romanies when the screening conditions were narrowed based on the population size to be over 40, the occurrence of the haplotypes was more than one and the sum frequencies of the most frequent haplotypes was at least 0.02. The most common haplotypes were also observed in other Romani groups. When searching with two Indian (Malbar and Malaysian Indian) most frequent haplotypes under the same conditions matches could be detected in all Romani populations except for the Macedonian Romanies. The search with the Jat Sikhs and Jats of Haryana most frequent haplotypes resulted no matches in Romani populations.  相似文献   
922.
This paper is the fifth in a series of six in relation to the development of a harmonised method for the profiling of amphetamine [L. Aalberg, K. Andersson, C. Bertler, H. Borén, M.D. Cole, J. Dahlén, Y. Finnon, H. Huizer, K. Jalava, E. Kaa, E. Lock, A. Lopes, A. Poortman-van der Meer, E. Sippola, Development of a harmonised method for the profiling of amphetamines I. Synthesis of standards and compilation of analytical data, Forensic Sci. Int. 149 (2005) 219-229; L. Aalberg, K. Andersson, C. Bertler, M.D. Cole, Y. Finnon, H. Huizer, K. Jalava, E. Kaa, E. Lock, A. Lopes, A. Poortman-van der Meer, E. Sippola, J. Dahlén, Development of a harmonised method for the profiling of amphetamines II. Stability of impurities in organic solvents, Forensic Sci. Int. 149 (2005) 231-241]. The third paper [K. Andersson, K. Jalava, E. Lock, L. Aalberg, Y. Finnon, H. Huizer, E. Kaa, A. Lopes, A. Poortman-van der Meer, M.D. Cole, J. Dahlén, E. Sippola, Development of a harmonised method for the profiling of amphetamines III. Development of the gas chromatographic method, Forensic Sci. Int., in press] dealt with the optimisation of the gas chromatographic and detection methods whereas the fourth paper [K. Andersson, K. Jalava, E. Lock, Y. Finnon, S. Stevenson, L. Aalberg, H. Huizer, E. Kaa, A. Lopes, A. Poortman-van der Meer, M.D. Cole, J. Dahlén, E. Sippola, Development of a harmonised method for the profiling of amphetamines IV. Optimisation of sample preparation, Forensic Sci. Int., in press] concerned the optimisation of the extraction method prior to GC analysis. This paper is a study of the optimised method in order to determine its stability. Investigations of within and between day variations were carried out in four laboratories. Moreover, variations between laboratories were also determined. Both flame ionisation detector (FID) and MS detection were used. One laboratory studied nitrogen-phosphorous detector (NPD) detection as well. For this task, 12 batches of amphetamine were prepared. Six of them were synthesised via the Leuckart route, three via the nitrostyrene route and three via the reductive amination route [A.M.A. Verweij, Impurities in illicit drug preparations: amphetamine and methamphetamine, Forensic Sci. Rev. 1 (1989) 2-11]. Taking into account all studied target compounds and the average results from four laboratories, the within day variation was around 6% for FID and 5% for MS, the between days variation was around 10% for FID and 8% for MS. For NPD detection, within day variation was 5% and between days variation 9% (only one laboratory). Finally, the inter-laboratory variation was about 12% for FID (four laboratories) and 10% for MS (three laboratories).  相似文献   
923.
The distribution profile of infiltrated mast cell-subpopulations and eosinophils in the lung and heart sections of the patients who died of severe allergic hyperresponsiveness, was investigated. Four study groups were designed comprising 9 cases who died in systemic anaphylaxis (Group I), 10 asthmatic individuals whose death were assigned to acute and severe bronchial asthma (Group II), 10 asthmatic cases who died from non-immunological diseases (Group III). Twenty consecutive autopsies of non-allergic subjects who died of unnatural causes (Group IV) served as control group in this study. Utilizing antibodies against human tryptase and chymase and a double immunohistochemical staining method, we distinguished successfully all three subsets of mast cells (MC), MC-TC (containing both tryptase and chymase), MC-T (containing only tryptase) and MC-C (containing only chymase) types, subdivided on the basis of the protease compositions of their secretory granules. In order to immunostaining eosinophils, we used antibody to major basic protein as a marker. We also measured postmortem blood tryptase, specific and total serum IgE. The intriguing finding of this study was the marked differences of cellular composition in the lung between fatal anaphylaxis and asthma death. Significant augmentation of MCs infiltrated in lung and heart sections of anaphylaxis patients and drastic infiltration of bronchial eosinophils in asthmatic death and consequent release of their related inflammatory mediators might explain the differential expression of the associated symptoms in these two groups. The anaphylactic deaths did show neither emphysema nor significant mucous bronchial secretions whereas all asthmatic deaths did. The degree of pulmonary congestion and edema was also more severe in anaphylaxis. This corresponded with the histological findings and the location and number of mast cell-subsets and eosinophils in the different compartments of the lungs. We have demonstrated that the third type of mast cell MC-C is only found in the lungs in anaphylactic deaths. The practical consequence of our study will be that it is now possible to confirm a suspicion of anaphylaxis death not only by measurements of serum mast cell tryptase, but also by immunohistochemical methods.  相似文献   
924.
Consultation of scientific evidence by policy actors has been the foci of attention of knowledge utilization scholars for decades. The present study questioned the extent to which randomized controlled trials (RCTs)—generally seen as the gold standard of scientific research—are known and consulted by policy analysts in ministerial settings. Using cross‐sectional data collected in 17 ministries in Québec (Canada), our study showed that fairly high levels of policy analysts report never having heard of RCTs, thus possibly hindering effective communication of scientific results to relevant policy makers. Statistical analyses reveal the importance of cognitive factors in explaining both phenomena.  相似文献   
925.
Debates about biotechnology continue to be polarized despite its potential to improve the living standards of the poor in Sub‐Saharan Africa. In the backdrop of this polarized scenario, this paper asked, is there a place for brokers in bringing about a productive debate that is pro‐development? The paper argued that if potential intermediaries are analyzed from the perspective of understanding their role and stakeholding in the regulatory change process, this may help breakout the current polarized anti‐ and pro‐biotechnology debates and thereby focus on how to enable productive biotechnology development. Informed by insights from innovation brokering, the functions of brokers in biotechnology regulation are analyzed through the lens of organizations involved in agricultural biotechnology debates in Kenya. The analysis found that policy brokering function attracts varying opportunities and challenges appropriate for informing relevant policy. The paper drew lessons from Kenya's experience to inform a productive policy brokering model for biotechnology regulation.  相似文献   
926.
It is common wisdom that public sector wages are not determined in the same way as private sector wages. At the same time, the empirical evidence available for OECD countries finds a strong positive correlation between public and private sector wages. In this paper, we develop a model that is consistent with a political economy view of the determination of public sector wages and employment, while being consistent with the said empirical evidence. Public finance constraints are crucial: In booms, governments expand employment and wages, while in downturns, lack of tax revenues forces the government to cut back the wage bill.  相似文献   
927.
This paper studies the influence of ideology and political motives on the choice of management for urban water services. Our contribution is two-fold. Firstly, we use a considerably more detailed set of variables to represent ideological and political motives than previous research. Secondly, the variables that explain local politicians’ decisions are observed at the time decision-making occurs, rather than at a later date. Beyond pragmatic reasons, we find that ideological and political motives also matter when explaining decisions regarding the management of water services. Furthermore, considering the time dimension of decision-making noticeably improves the explanatory power of our model.  相似文献   
928.
Now that state governments issue comprehensive annual financial reports in accordance with Statement No. 34 of the Governmental Accounting Standards Board, it is possible to generate a consistent and comprehensive set of government‐wide financial information. We use the information to develop financial ratios to benchmark government financial performance from information beyond the traditional general fund, and test the hypothesis that such information is incorporated into the assessment of credit risk. We provide an empirical analysis of the incorporation of government‐wide financial information into state government credit ratings, which provides a positive empirical test of the theory of certification and demonstrates how information from the government‐wide financial statements is infused into financial markets.  相似文献   
929.
The extent of strategic voting in the Spanish general elections of 2000, 2004 and 2008 is estimated using a new measure of strategic incentives suitable for proportional representation systems that avoids some of the problems associated with lagged variables. Strategic behaviour increased from 12 to 33 per cent of the electoral base of the United Left Party, the major victim of strategic defection. This estimate is a conservative one as elite mobilisation is controlled for in the constituencies, which is unusual in the literature on strategic voting that uses regression‐based methods.  相似文献   
930.
Cognitive biases are heuristics that shape individual preferences and decisions in a way that is at odds with means‐end rationality. The effects of cognitive biases on governing are underexplored. The authors study how election administrators’ cognitive biases shape their preferences for e‐voting technology using data from a national survey of local election officials. The technology acceptance model, which employs a rational, means‐end perspective, suggests that the perceived benefits of e‐voting machines explain their popularity. But findings indicate that cognitive biases also play a role, even after controlling for the perceived benefits and costs of the technology. The findings point to a novel cognitive bias that is of particular interest to research on e‐government: officials who have a general faith in technology are attracted to more innovative alternatives. The authors also find that local election officials who prefer e‐voting machines do so in part because they overvalue the technology they already possess and because they are overly confident in their own judgment.  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