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   1958篇
  免费   103篇
各国政治   167篇
工人农民   71篇
世界政治   206篇
外交国际关系   168篇
法律   782篇
中国政治   23篇
政治理论   620篇
综合类   24篇
  2023年   10篇
  2022年   6篇
  2021年   17篇
  2020年   34篇
  2019年   59篇
  2018年   56篇
  2017年   78篇
  2016年   101篇
  2015年   58篇
  2014年   72篇
  2013年   347篇
  2012年   63篇
  2011年   57篇
  2010年   61篇
  2009年   68篇
  2008年   67篇
  2007年   80篇
  2006年   82篇
  2005年   71篇
  2004年   54篇
  2003年   70篇
  2002年   69篇
  2001年   35篇
  2000年   52篇
  1999年   33篇
  1998年   50篇
  1997年   30篇
  1996年   35篇
  1995年   32篇
  1994年   22篇
  1993年   15篇
  1992年   21篇
  1991年   8篇
  1990年   21篇
  1989年   7篇
  1988年   22篇
  1987年   15篇
  1986年   6篇
  1984年   8篇
  1983年   7篇
  1982年   7篇
  1981年   7篇
  1980年   6篇
  1979年   11篇
  1978年   3篇
  1977年   7篇
  1975年   4篇
  1970年   3篇
  1965年   2篇
  1964年   2篇
排序方式: 共有2061条查询结果,搜索用时 15 毫秒
361.
362.
The theory of action upon which high‐stakes accountability policies are based calls for systemic reforms in educational systems that will emerge by pairing incentives for improvement with extensive and targeted technical assistance (TA) to build the capacity of low‐performing schools and districts. To this end, a little discussed and often overlooked aspect of the No Child Left Behind Act (NCLB) mandated that, in addition to sanctions, states were required to provide TA to build the capacity of struggling schools and Local Education Agencies (LEAs, or districts) to help them improve student achievement. Although every state in the country provides some form of TA to its lowest performing districts, we know little about the content of these programs or about their efficacy in improving student performance. In this paper, we use both quantitative and qualitative analyses to explore the actions taken by TA providers in one state—California—and examine whether the TA and support tied to California's NCLB sanctions succeeds in improving student achievement. Like many other states, California requires that districts labeled as persistently failing under NCLB (in Program Improvement year 3, PI3) work with external experts to help them build the capacity to make reforms that will improve student achievement. California's lowest performing PI3 districts are given substantial amounts of funding and are required to contract with state‐approved District Assistance and Intervention Teams (DAITs), whereas the remaining PI3 districts receive less funding and are asked to access less intensive TA from non‐DAIT providers. We use a five‐year panel difference‐in‐difference design to estimate the impacts of DAITs on student performance on the math and English language arts (ELA) standardized tests relative to non‐DAIT TA during the two years of the program intervention. We find that students in districts with DAITs perform significantly better on math California Standards Tests (CSTs) averaged over both treatment years and in each of the first and second years. We do not find evidence that students in districts with DAITs perform higher on ELA CSTs over the combined two years of treatment, although we find suggestive evidence that ELA performance increases in the second year of treatment relative to students in districts with non‐DAIT TA. Ordinary least squares (OLS) regressions that explore the association between specific activities fostered by DAITs and changes in districts’ gains in achievement over the two years of treatment show that DAIT districts that report increasing their focus on using data to guide instruction, shifting district culture to generate and maintain high expectations of students and staff, and increasing within‐district accountability for student performance, have higher math achievement gains over the course of the DAIT treatment. In addition, DAIT districts that increase their focus on ELA instruction and shift district culture to one of high expectations have higher ELA achievement gains than do DAIT districts that do not have a similar focus. © 2012 by the Association for Public Policy Analysis and Management.  相似文献   
363.
364.
365.
Mortgage fraud is a fast-growing form of white-collar crime that has received much press coverage in the United States of America. Mortgage fraud has an adverse effect on individual homeowners, communities, and many indirect victims of the crime. While past research has focused on the personal motivating factors behind the commission of white-collar crime, this particular article reviews several facets of the crime itself and explores the potential neighbourhood risk factors that help attract the crime. From a national perspective, mortgage fraud seems to occur more frequently in neighbourhoods that have low socioeconomic indicators. These associations become even more pronounced when the degree of fraud occurrences within the community is factored in as a variable. Upon disaggregating the data according to region, the fraud indicator variables also display differing trend levels, perhaps indicating that as mortgage fraud practices begin to mature within an area, its community dynamics tend to change as well. The article concludes with recommendations for policymakers, community organizations, and law enforcement officials as to how to address mortgage fraud once it appears within a community, and also addresses future avenues of research for what is largely an untapped area of financial crime research.  相似文献   
366.
One common rationale supporting public financing programs for small firms is that initial public investment creates incentives for follow-on private investment. However, there does not appear to be a unified statement in the literature describing how initial public investment creates incentives for follow-on private investment. Focusing on external private investors, we use a two-stage net present value model to identify four effects from initial public investment on the private decision for follow-on investment. Our empirical analysis uses a sample of non-venture backed firms entering the SBIR program to examine how reduced risk, the number of SBIR awards, and size of initial public investment influence the likelihood of follow-on venture capital investment. We find the probability of follow-on venture capital investment is more likely when firms reach Phase II of the program, is less likely as firms win multiple Phase I and Phase II awards, and is more likely as the size of initial public investment in Phase I increases.
Calum TurveyEmail:
  相似文献   
367.
This paper offers an economic rationale for compulsory licensing of needed medicines in developing countries. The patent system is based on a trade-off between the "deadweight losses" caused by market power and the incentive to innovate created by increased profits from monopoly pricing during the period of the patent. However, markets for essential medicines under patent in developing countries with high income inequality are characterized by highly convex demand curves, producing large deadweight losses relative to potential profits when monopoly firms exercise profit-maximizing pricing strategies. As a result, these markets are systematically ill-suited to exclusive marketing rights, a problem which can be corrected through compulsory licensing. Open licenses that permit any qualified firm to supply the market on the same terms, such as may be available under licenses of right or essential facility legal standards, can be used to mitigate the negative effects of government-granted patents, thereby increasing overall social welfare.  相似文献   
368.
The application of isotopic techniques to investigations requiring the provision of evidence to a Court is limited. The objective of this research was to investigate the application of light stable isotopes and isotope ratio mass spectrometry (IRMS) to solve complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques.Due to the current threat of organic peroxide explosives, such as triacetone triperoxide (TATP), research was undertaken to determine the potential of IRMS to differentiate samples of TATP that had been manufactured utilising different starting materials and/or manufacturing processes. In addition, due to the prevalence of pentaerythritoltetranitrate (PETN) in detonators, detonating cord, and boosters, the potential of the IRMS technique to differentiate PETN samples from different sources was also investigated.Carbon isotope values were measured in fourteen TATP samples, with three definite groups appearing in the initial sample set based on the carbon data alone. Four additional TATP samples (in a second set of samples) were distinguishable utilising the carbon and hydrogen isotopic compositions individually, and also in combination with the oxygen isotope values. The 3D plot of the carbon, oxygen and hydrogen data demonstrated the clear discrimination of the four samples of TATP. The carbon and nitrogen isotope values measured from fifteen PETN samples, allowed samples from different sources to be readily discriminated.This paper demonstrates the successful application of IRMS to the analysis of explosives of forensic interest to assist in discriminating samples from different sources. This research represents a preliminary evaluation of the IRMS technique for the measurement of stable isotope values in TATP and PETN samples, and supports the dedication of resources for a full evaluation of this application in order to achieve Court reportable IRMS results.  相似文献   
369.
An evaluation was undertaken to determine if isotope ratio mass spectrometry (IRMS) could assist in the investigation of complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. The focus of the research was on ammonium nitrate (AN), a common oxidiser used in improvised explosive mixtures.The potential value of IRMS to attribute Australian AN samples to the manufacturing source was demonstrated through the development of a preliminary AN classification scheme based on nitrogen isotopes. Although the discrimination utilising nitrogen isotopes alone was limited and only relevant to samples from the three Australian manufacturers during the evaluated time period, the classification scheme has potential as an investigative aid.Combining oxygen and hydrogen stable isotope values permitted the differentiation of AN prills from three different Australian manufacturers. Samples from five different overseas sources could be differentiated utilising a combination of the nitrogen, oxygen and hydrogen isotope values. Limited differentiation between Australian and overseas prills was achieved for the samples analysed.The comparison of nitrogen isotope values from intact AN prill samples with those from post-blast AN prill residues highlighted that the nitrogen isotopic composition of the prills was not maintained post-blast; hence, limiting the technique to analysis of un-reacted explosive material.  相似文献   
370.
Legal context: There exists, in some countries, a patent attorney privilege.This privilege allows an actual or potential holder of patentrights to withhold from a court communications that it has hadwith its patent attorney. The privilege is not recognized inall jurisdictions and there is variation in the extent of theprivilege in those countries where it does exist. Key points: This article explores the rationale for the privilege in orderto see if there is a sound basis upon which to found it. Througha consideration of the justifications for other legal privileges,the article finds that patent attorney privilege is a justifiableprotection for communications between clients and their patentattorneys. If there was a possibility that the communicationswould have to be revealed in court, this may impact the fulland frank nature of the communications. Such communicationsassist patent attorneys, as professionals with expertise ina specialized field, to provide clients with appropriate andeffective advice. That advice goes directly to the maintenanceand benefit of the patent system and the overall economy. Practical significance: As a result of the variation in the extent of the privilegearound the world, there are moves afoot to reform its operation.This article reveals strong public policy reasons for the recognitionof a patent attorney privilege. These grounds also reinforcethe need to ensure that privilege is not unduly limited in itsoperation in any jurisdiction.  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