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   875篇
  免费   44篇
各国政治   71篇
工人农民   56篇
世界政治   78篇
外交国际关系   55篇
法律   425篇
中国共产党   1篇
中国政治   9篇
政治理论   211篇
综合类   13篇
  2023年   12篇
  2022年   9篇
  2021年   12篇
  2020年   28篇
  2019年   29篇
  2018年   53篇
  2017年   49篇
  2016年   50篇
  2015年   36篇
  2014年   32篇
  2013年   128篇
  2012年   37篇
  2011年   28篇
  2010年   27篇
  2009年   16篇
  2008年   32篇
  2007年   31篇
  2006年   26篇
  2005年   32篇
  2004年   40篇
  2003年   19篇
  2002年   18篇
  2001年   18篇
  2000年   15篇
  1999年   6篇
  1998年   10篇
  1997年   10篇
  1996年   6篇
  1995年   3篇
  1994年   6篇
  1993年   3篇
  1992年   3篇
  1991年   7篇
  1990年   4篇
  1989年   10篇
  1988年   3篇
  1987年   9篇
  1986年   5篇
  1985年   8篇
  1983年   4篇
  1982年   8篇
  1981年   3篇
  1980年   4篇
  1978年   3篇
  1977年   3篇
  1973年   3篇
  1968年   2篇
  1967年   4篇
  1964年   2篇
  1963年   2篇
排序方式: 共有919条查询结果,搜索用时 15 毫秒
841.
Abstract:  Effectively addressing marijuana trade is aided by understanding marijuana geographic sources. We analyzed the 87Sr/86Sr of marijuana samples grown in 79 counties across the United States to determine if a primary geologic signal is retained in marijuana, which could therefore be useful for geographic sourcing. The marijuana results were compared with modeled bedrock 87Sr/86Sr values based on 87Rb decay rates and a generalized geologic map of the U.S.A. A significant correlation was observed between marijuana 87Sr/86Sr and modeled bedrock 87Sr/86Sr. Although values clustered near the 1:1 relationship, there was a predominance of positive anomalies, perhaps attributable to carbonate bedrock. A small number of negative anomalies were also observed, which were generally associated with granitic bedrocks. These results suggest that strontium isotopes in marijuana record the geographic origins of marijuana, and that refinement of the base strontium map (or strontium isoscape) and improved understanding of other strontium sources would be productive.  相似文献   
842.
Sommaire : Les politiques publiques du travail ont été conçues pour offrir des mesures de protection aux salariés travaillant à temps plein, pour un seul employeur, sous son contrôle et sur les lieux de l'entreprise. Or, le marché du travail est aujourd'hui composé d'une pluralité de relations d'emploi qui limitent l'efficacité de ces protections. Ce constat soulève la question suivante : que devraient contenir les politiques publiques pour être mieux adaptées au marché du travail? La première partie de cet article examine les voies de renouvellement possible des politiques publiques pour tenir compte des transformations du travail et de l'entreprise. Certaines suggèrent de faire reposer l'octroi de droits et d'avantages sur l'existence d'un travail ou d'une activité professionnelle alors que d'autres les rattachent à l'individu ou au citoyen. Ces propositions ne pourront cependant voir le jour que si elles font l'objet d'une appropriation par les acteurs sociaux et étatiques. Une réflexion sur le contenu des politiques doit ainsi être combinée à l'étude des processus sociaux susceptibles de faire émerger de telles réformes. Cette question est abordée dans la deuxième partie de l'article à partir de trois exemples récents de réformes législatives. Abstract: Public labour policies were developed to ensure the protection of workers who work for one employer on a full‐time basis, at the employer's place of work and under his control. However, today's labour market is composed of a multiplicity of employment relations that limit the effectiveness of the protection. This raises the following question: what features should public policies include to better meet the needs of the labour market? The first part of this article examines how public policies could be renewed in order to take work and organizational transformations into account. Some policies suggest that rights and benefits should be granted on the basis of a job or professional activity, whereas others link rights and benefits to the individual or the citizen. However, these proposals will only emerge if they are appropriated by social and governmental stakeholders. A reflection on the content of the policies must therefore be undertaken in combination with a study of the social processes that may influence the emergence of such reforms. This question is examined in the second part of the article through a review of three recent examples of legislative reform initiatives.  相似文献   
843.
How to teach negotiation cannot be effectively summed up in a few ready‐to‐be‐applied principles. In this article, I define a paradoxical professorial stance that I believe can be useful for helping students learn negotiation concepts and methods, and will also help them reflect on their own practice. The paradoxes are the following: caring for the students while deliberately exposing them to frustration; nurturing a lively, interactive course while respecting those students who prefer to remain silent; helping the students to be more autonomous while simultaneously manipulating them; accepting their vulnerability while nurturing their creativity; and finally, maintaining both professorial distance and closeness. My adoption of such a paradoxical stance as a professor has encouraged greater creativity in my students, and by the end of the course, they are better able to create value in a negotiation simulation.  相似文献   
844.
Victim identification using dental records involves antemortem and postmortem comparison of dental charts. Since dental restorations may be part of such records, identifying them accurately is critical. The objective of this study was to compare the diagnostic reliability and validity of two optical methods for identifying tooth‐colored restorations (digital imaging fiber optic transillumination (DiFOTI) using near infrared light, and fluorescence‐aided identification of restorations (FAIR)) with conventional diagnostic methods. Four examiners identified and charted tooth‐colored restorations in three sets of typodonts on the bench using conventional visual and tactile examination, DiFOTI (DIAGNOcam?) and FAIR. All examinations were repeated after 4 weeks. Both the sensitivity (95%) and specificity (97%) of the FAIR method were significantly higher than those for DiFOTI (82% and 82%) and for conventional inspection (71% and 82%). In conclusion, FAIR method performed better than conventional examination and DiFOTI, and was more reliable for identifying tooth‐colored restorations.  相似文献   
845.

This paper analyses the allocation of R&D investments within rare diseases and identifies the characteristics of rare diseases that appear to lead R&D resources. Rare diseases affect less than 1 in 2000 citizens. With over 7000 recognised rare diseases and 350 million people affected worldwide, rare diseases are not so rare when considered collectively. Rare diseases are generally underserved by drug development because pharmaceutical industries consider R&D investments in rare diseases too costly and risky in comparison with the low expected returns due to the small population involved. We use data on rare diseases research from Orphanet along with academic publications per rare disease from bibliographic databases. We test the existence of inequalities in R&D investments within rare diseases and identify the disease characteristics that appear to lead R&D investments using dominance tools and bilateral tests. We show that rare diseases in children and with a smaller prevalence, such as ultra-rare diseases, are underserved by R&D. R&D investments appear to be concentrated in more profitable research areas with potentially larger sample size and adult population.

  相似文献   
846.
In criminal activities, soil can be transferred from a crime scene to items linked with a perpetrator; for example, shoes, cars or tools. Several parameters will influence the quantity of soil transferred in a given scenario. The knowledge of the most influential factors can help the expert to assess the evidence using a logical approach at the activity level or to predict the amount of soil that can be expected in a given scenario. The influence of five chosen parameters, namely the shoe profile, shoe size, walker's weight, soil type and soil humidity were assessed using Design of Experiment (DOE) in order to understand their influence on soil quantity transferred on shoes.The Faced Central Composite Design (FCCD) using a quadratic model was found to be highly significant, thus they could be adequately used to model and to interpret the amount of soil recovered from one shoe.These designs demonstrate that the characteristics of the donor (soil type and soil humidity), as well as a combination of these two factors have a very significant impact on the soil transfer. The characteristics of the receptor (shoe profile, shoe size and walker's weight) also have an impact on the transfer but to a lesser extent.Globally, this research provides valuable information for the forensic scientist both in investigative mode: evaluation of the soil quantity possibly transferred on shoes, and in the evaluative steps: is the quantity of soil found on the suspect shoes in accordance to the proposition/scenario given by the prosecution and the defence?  相似文献   
847.
The international fight against money laundering illustrates changes in global governance as a result of the increasingly cross-border nature of crime and the need it creates for all involved to cooperate. The economic priorities and security concerns that surround it contributed to the strong evolution of global governance in this area and the status of anti-money laundering as a shared problem. The creation of the Financial Action Task Force (FATF), its expansion and cementation throughout the years, is a good example of the many forces working together to responding to the demands of emerging criminal threats and trends. It offers a good illustration of how relationships in global governance have influenced FATF’s priorities and action and ultimately the way in which illicit financial flows are tackled. This analysis offers an overview of FATF’s network across time taking into account the role of states, international organisations, and the private sector in the decision-making processes. It argues that Great Powers – a small, but aligned, group of states of global economic relevance – are responsible for FATF’s direction and the international efforts against illicit financial flows. It suggests, however, that unlike what could be expected, their power is declining following the rise of private sector influence through resourceful, organised and transnational actions e.g. on information sharing.  相似文献   
848.
Private companies want to eliminate outgoing spillovers while policymakers seek to maximize them. With subsidized R&D cooperation agreements both agents partially achieve their objectives. For this reason, in Europe, policymakers grant subsidies for R&D activities with the condition of establishing R&D cooperation agreements. This study explores the relationship of complementarity between R&D subsidy, R&D cooperation and absorptive capacity in the context of its contribution to labor productivity of enterprises. The data used comes from the Technological Innovation Panel (PITEC), managed by the Spanish National Statistics Institute. We selected manufacturing companies in the period 2008–2013. We evaluate the existence of complementarity through the systems approach and the interaction approach. The econometric technique that we used to estimate the coefficients of our empirical model was maximum-likelihood random effects. As a consequence of the low absorptive capacity of Spanish manufacturing firms we find that R&D subsidies and R&D cooperation agreements are not complementary variables, i.e., receiving public subsidies as a result of establishing R&D cooperation agreements has a lower impact on productivity than the sum of the individual impacts of R&D cooperation and R&D subsidies. In consequence, this result calls into question the convenience of using subsidized R&D cooperation agreements as a tool for promoting innovation in EU countries as there are notable differences between the companies in these countries in terms of absorption capacity.  相似文献   
849.
The variation in the epidermal ridge's width between the sexes, during various growth stages, and among different populations has been previously assessed. However, the changes that occur with aging are barely known.The goal of this study was to analyse the degree of variation in epidermal ridge width due to aging. So that, fingerprint ridge density was estimated to establish their relationship with body and hand size changes that typically occur in adulthood.In this study, a sample of 213 adults of both sexes from a Spanish native population of different age ranges—18–30?years old (“junior” group) and 50–66?years old (“senior” group)—was used. Ridge density was assessed in three counting areas of the distal phalanx of each finger (radial, ulnar, and proximal). Height, weight, and a set of anthropometric measurements for both hands were also taken.Our results show that ridge density is higher in females than males throughout adulthood and decreases with aging in the radial and ulnar areas (as the hands widen) but not in the proximal region. Thus, a relationship between hand dimensions and ridge density was found.The data indicate that aging changes may conceal the recognized sex differences in ridge density, and so a better understanding of the topological variations in the epidermal ridge width throughout the life cycle and the factors involved would facilitate the interpretation of the differences between the sexes and different age groups.  相似文献   
850.
Using aggregated data from 25 developed countries over a lengthy period of time, this article presents a measure of the marriage boom observed in the twentieth century and an explanation for its causes. One of my main conclusions is that even though it basically developed after the Second World War, its origins are to be found before it. I found that, contrary to the views of some scholars, this boom was not a short-lived phenomenon, but actually lasted for 90 years on average. Using panel data analysis techniques, I am able to show that the rise in women’s education, state spending on social benefits, and larger percentages of people employed in the primary sector tended to discourage marriage. I also found a quadratic relationship between the nuptiality index and the per capita income and mortality rates.  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