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   7410篇
  免费   175篇
各国政治   384篇
工人农民   204篇
世界政治   487篇
外交国际关系   288篇
法律   4640篇
中国共产党   1篇
中国政治   19篇
政治理论   1469篇
综合类   93篇
  2020年   67篇
  2019年   85篇
  2018年   130篇
  2017年   137篇
  2016年   153篇
  2015年   114篇
  2014年   137篇
  2013年   801篇
  2012年   201篇
  2011年   197篇
  2010年   155篇
  2009年   166篇
  2008年   196篇
  2007年   177篇
  2006年   188篇
  2005年   148篇
  2004年   157篇
  2003年   161篇
  2002年   162篇
  2001年   309篇
  2000年   277篇
  1999年   221篇
  1998年   82篇
  1997年   104篇
  1996年   79篇
  1995年   82篇
  1994年   93篇
  1993年   82篇
  1992年   160篇
  1991年   178篇
  1990年   158篇
  1989年   173篇
  1988年   148篇
  1987年   143篇
  1986年   165篇
  1985年   126篇
  1984年   125篇
  1983年   129篇
  1982年   77篇
  1981年   79篇
  1980年   59篇
  1979年   111篇
  1978年   64篇
  1977年   61篇
  1976年   56篇
  1975年   67篇
  1974年   83篇
  1973年   77篇
  1972年   67篇
  1971年   60篇
排序方式: 共有7585条查询结果,搜索用时 15 毫秒
21.
With new technically advanced methods and computers at our disposal, the efficient market hypothesis is once again being debated. At the same time, we are witnessing an unprecedented growth in both existing and new financial markets. These new markets are often in economies which have just recently embraced free market economics; we term these stock markets infant markets. Such stock markets are obviously not efficient in allocating the supply of savings to productive capital. We do not test whether or not these infant markets are informationally efficient, but instead examine whether and how they are becoming more efficient. We propose modelling the excess returns of individual securities using a multi-factor model with time-varying coefficients and generalised auto-regressive conditional heteroskedastic (GARCH) errors. If the markets are becoming more informationally efficient or the agents are learning, we would expect this to manifest itself as the time-varying coefficients becoming more stable as time increases. We test our model using data on four Bulgarian shares. First, we estimate an AR(2) model and a GARCH-M(1,1) model for the shares. Then, we estimated our AR(2) model with time varying coefficients and GARCH type errors. We find varying levels of efficiency and varying speeds of movement towards efficiency within our sample of four shares.  相似文献   
22.
23.
24.
The Tax Reform Act of 1986 rewrote the federal income tax code, bringing it closer to policy professionals' vision of what constitutes an equitable and efficient income tax. Research on tax compliance suggests the law might have affected taxpayer compliance in three ways: by reducing opportunities to overstate deductions, by changing perceptions of fairness, and by altering tax liabilities. Changes in taxpayer perceptions, attitudes, and noncompliance intentions were examined in three bodies of survey data, each containing pre-and post-reform data from independent samples of the same population. The results show an improved normative climate for taxpayer compliance and point to both the feasibility and the importance of examining the effects of substantive tax policies on taxpayer perceptions, attitudes, and behavioral intentions.  相似文献   
25.
The formation of adequate mental health systems within prisons has accelerated as a result of successful class action lawsuits. Our recent national survey questioned all state correctional departments about the existence of standards in each system, compliance with such standards, prevalence of class action lawsuits involving the issue of providing adequate mental health services for inmates, issues related to consent decrees, available mental health resources within the correctional system, and the administrative structure of the mental health system. Our purpose was to identify those factors correlated with certified class action lawsuits involving issues related to mental health services. Twenty-one states were involved in such litigation. Only the presence of psychiatric hospitals operated by the department of corrections correlated with the presence of certified class action lawsuits involving mental health services. Prison systems larger than 15,000 inmates were at higher risk for such litigation. Smaller systems having psychiatric hospitals run by the state mental health agency appeared to be at less risk for such litigation.  相似文献   
26.
The Green River Murder Investigation in King County, Washington, is currently the longest active serial murder investigation in U.S. history. During its course, over 26 separate scenes with from one to five victims each have been processed. The experience of the authors is presented in order to acquaint other agencies with techniques of outdoor scene processing that have evolved during recovery of remains from Green River and other skeletal cases.  相似文献   
27.
On the one hand the following case demonstrates the problems of finding a dead body in the bathroom and on the other hand the importance of postmortem x-ray examinations. The corpse of an 65-year-old woman was discovered in her bath tub. At the body's feet there was a hair dryer. Investigations concerning murder were negative, circumstances appeared to be unsuspicious. That was why a postmortem examination was not performed. -4 years later murder had to be considered. After manual strangling the deceased and the hair dryer were layed into the bath tub. The corpse was exhumed and taken to a forensic autopsy. It was found that the hyoid bone and the superior horn of the thyroid cartilage were both fractured on the right. Damages caused by the preparation itself were excluded by using serial roentgenographs. These observations in combination with histological findings and the results of further investigations convincingly supported the suspicion of strangling by hand.  相似文献   
28.
Misidentification syndromes have been studied from a variety of perspectives, including phenomenological, biological, and nosological approaches. More recently, misidentification syndromes have been studied from a psychiatric-legal perspective, especially with regards to the problem of dangerousness. Capgras syndrome and other syndromes of misidentification can lead to hostile mood and subsequent physical violence. Little attention has so far been devoted to children as the objects of the psychotic person's misidentification delusion(s). We provide a review of cases from the anglophonic literature that have children as the misidentified objects, add three new cases, and then discuss the relationship between misidentification and potential harm to these children.  相似文献   
29.
30.
A gas chromatographic (GC) fingerprint method, based on the presence or absence of six congeners, was developed for illicit cocaine samples. The fingerprint utilizes the relative abundances of these congeners towards each other, disregarding cocaine as the main constituent, and can be expressed numerically or graphically in the form of pictograms for rapid visual comparison. The method can be applied directly to a solution of the sample in chloroform, without previous workup procedures. More than 70 unrelated samples were analyzed and a great variation was observed in the parameter composition. On the other hand, a remarkable similarity could be seen between related samples. The GC fingerprint method may be considered an important contribution for sample comparison, as is exemplified by a subdivision of the analyzed samples in different categories, based on the number and types of congeners found.  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