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   69504篇
  免费   3303篇
各国政治   4539篇
工人农民   2907篇
世界政治   6214篇
外交国际关系   3863篇
法律   32683篇
中国共产党   30篇
中国政治   798篇
政治理论   20788篇
综合类   985篇
  2023年   367篇
  2021年   418篇
  2020年   1177篇
  2019年   1542篇
  2018年   1701篇
  2017年   1996篇
  2016年   2205篇
  2015年   1851篇
  2014年   2115篇
  2013年   10586篇
  2012年   1649篇
  2011年   1763篇
  2010年   1850篇
  2009年   2105篇
  2008年   1763篇
  2007年   1744篇
  2006年   1929篇
  2005年   1841篇
  2004年   1705篇
  2003年   1497篇
  2002年   1542篇
  2001年   1718篇
  2000年   1433篇
  1999年   1297篇
  1998年   1140篇
  1997年   986篇
  1996年   956篇
  1995年   920篇
  1994年   927篇
  1993年   950篇
  1992年   1002篇
  1991年   1029篇
  1990年   994篇
  1989年   998篇
  1988年   990篇
  1987年   1001篇
  1986年   979篇
  1985年   1042篇
  1984年   957篇
  1983年   993篇
  1982年   888篇
  1981年   835篇
  1980年   662篇
  1979年   715篇
  1978年   595篇
  1977年   528篇
  1976年   491篇
  1975年   407篇
  1974年   413篇
  1973年   418篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Novel psychoactive substances (NPS) are synthetic drugs that pose serious public health and safety concerns. A multitude of NPS have been identified in the United States, often implicated in forensic investigations. The most common and effective manner for identifying NPS is by use of mass spectrometry and the true utility lies within nontargeted acquisition techniques. During this study, a liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) assay was developed, validated, and implemented for forensic toxicology testing. A SCIEX TripleTOF™ 5600 + with SWATH® acquisition was used. Resulting data were compared against an extensive library database containing more than 800 compounds. The LC-QTOF-MS assay was applied to the reanalysis of biological sample extracts to discover emergent NPS. More than 3,000 sample extracts were analyzed, and more than 20 emerging NPS were detected for the first time. Among these were isopropyl-U-47700, 3,4-methylenedioxy-U-47700, fluorofuranylfentanyl, N-methyl norfentanyl, 2F-deschloroketamine, 3,4-methylenedioxy-alpha-PHP, eutylone, and N-ethyl hexedrone.  相似文献   
32.
A simple, quick, selective, sensitive, and effective field-friendly method capable of being used by nonexperts has been developed for detecting mitragynine in Mitragyna speciosa (kratom) using surface-enhanced Raman spectroscopy (SERS). Over 100 samples and blanks (known to be either positive or negative for the presence of mitragynine) were examined in duplicate using five identical handheld Raman spectrometers, which provided a data set of over 1,000 examinations. Based on the results of these analyses, the method yielded a true-positive rate of 99.3%, a true-negative rate of 97.9%, a false-positive rate of 2.1%, and a false-negative rate of 0.7%. The average minimum detectable concentration (Cm) of mitragynine that reproducibly yielded a match for one of the library spectra on all five instruments was determined to be 342 ng/mL (ppb). This Cm value is a conservative estimate considering that the extraction process was not fully optimized by this study, which was not necessary since the Cm value achieved was well below typical mitragynine concentrations in kratom (1.3–2.3%). The method is ideal (i) for prioritizing samples for additional testing using other more time-consuming laboratory-based techniques needed to detect and quantify mitragynine and (ii) for field use at international mail facility (IMF) satellite laboratories to help interdict kratom and prevent this dangerous product from reaching the U.S. supply chain.  相似文献   
33.
Following 9/11, Al-Qaeda-orchestrated plots were considered the greatest threat to Western security and sparked the coalition’s war on terror. Close to a decade later, the post-9/11 threat landscape had shifted significantly, leading then CIA-director Leon Panetta to describe “the lone-wolf strategy” as the main threat to the United States. Subsequent lone-actor attacks across the West, including the cities of London, Nice, Berlin, Stockholm, Ottawa and Charleston, further entrenched perspectives of a transformed security landscape in the “after, after-9/11” world. The unique features of lone-actor terrorism, including the challenges of interdiction and potential of copycat attacks, mean that the media is likely to play a particularly important role in shaping the reactions of the public, affected communities and copycat attackers. This article presents findings from a content analysis of British and Danish newspaper reporting of lone-actor terrorism between January 2010 and February 2015. The study highlights that lone-actor terrorism is framed, with national variations, as a significant and increasing problem in both countries; that Islamist lone-actors are often represented as distinct from far-right lone-actors; and that some reporting, despite relatively limited amplification of specific terrorist messages, potentially aids lone-actors by detailing state vulnerabilities to attacks.  相似文献   
34.
Objectives

This study was an attempt to replicate the findings from an earlier experimental evaluation of a probation officer training program by Bonta et al. (Criminal Justice and Behavior, 38: 1127–1148, 2011). An experimental design was used with an improvement in the random assignment of clients and was tested with a sample of probation officers from a new jurisdiction.

Methods

Probation officers from the Canadian province of Alberta were randomly assigned to training or probation-as-usual. Officer behavior was measured by audio recordings of supervision sessions and recidivism was defined as a new conviction within 2 years of the initial recording. Attrition resulted in 27 probation officers submitting audio recordings of supervision sessions over a 6-month period (15 in the experimental group and 12 in the control). There were 160 recordings of 81 probationers submitted.

Results

The audio recordings showed inconsistent changes in officer behavior and no differences in recidivism between the clients of the experimental and control probation officers. However, the use of cognitive techniques by the probation officers was associated with a longer time to recidivism. In addition, by 10 months, more than half of the trained officers stopped their involvement in ongoing professional development activities.

Conclusion

Although the study failed to replicate the major findings reported by Bonta et al., it did highlight the importance of cognitive techniques in officer training. The results are interpreted with respect to the replication literature and the difficulties inherent in direct and conceptual replications especially in real-world settings.

  相似文献   
35.
ABSTRACT

Recently, “problem-solving” courts have been developed as an alternative to imprisonment. They are often called “specialty” courts because they process and divert into treatment programs offenders who are seen as different from the general criminal population, such as those with mental health or drug problems, those who are homeless or veterans, and those who engage in domestic violence. Based on a 2017 national survey of 1,000 respondents, the current study examines overall public support for rehabilitation as a goal of corrections and then focuses specifically on support for different types of specialty courts. The analysis reveals that the American public endorses not only the rehabilitative ideal but also the use of problem-solving courts. Further, with only minimal variation, strong support for these courts appears to exist regardless of political orientation and sociodemographic characteristics.  相似文献   
36.
Journal of Youth and Adolescence - Language brokering is a prevalent phenomenon in ethnic minority immigrant populations. Although accruing evidence points to the beneficial impacts of healthy role...  相似文献   
37.
Abstract

What is ‘relational theorizing’ in International Relations and what can it offer? This article introduces a thematic section that responds to these questions by showing two things. First, relational theorizing is not a doctrine or a method, but a set of analyses that begin with relations rather than the putative essences of constitutively autonomous actors. Second, relational theorizing has emerged from different geo-linguistic traditions, and a relational approach to International Relations (IR) can offer the language and space for increased and productive engagement beyond Anglophone scholarship. This thematic section takes a significant step in this direction by staging a dialogue between Sinophone and Anglophone scholarship on relational IR theorizing. Such an engagement shows points of comparison and contrast, convergence and divergence. In this way, the essays presented here contribute to developing a more ‘global’ IR.  相似文献   
38.
Governments are increasingly implementing smart and digital approaches to promoting citizen participation. However, whether online participation platforms are tools that improve inclusivity in citizen participation remains underexplored. To address this gap, this article focuses on the role of recruitment messages and their effect on participation in an online participation platform by gender and age. A field experiment with a neighborhood census sample (N = 6,066) shows that online participation dips for younger and older citizens and is equal among women and men. For the age groups between 60 and 75, differences in the control and intervention recruitment messages significantly impacted participation. These findings can help public managers tailor recruitment strategies to facilitate inclusive participation and represent a first step toward learning what types of messages are effective for whom.  相似文献   
39.
The increased use of information and communication technologies (ICTs) has triggered enormous innovation in the public sector and created positive public value at the managerial, delivery of services, and policy levels. However, these positive outcomes do not automatically accrue simply by adoption of ICTs as public leaders can fail to adopt relevant new ICTs, use them poorly, or use them in ways that actually diminish public value, which raises the question of the importance of e-leadership. This article examines e-leadership and innovation capacity at the individual public manager level and fills in some gaps about the practice and implementation of ICTs in the public sector. We explore eight research questions useful in theorizing about e-leadership, develop constructs of e-leadership, and describe the current development of e-leadership. By comparing e-leadership in two country settings (South Korea and the United States), we also overcome the limitations of the existing Western-oriented studies about innovations in the public sector. In addition to the growth of e-leadership use and requirements for a variety of competencies equivalent to, but separate from, traditional communication competences, we find that national cultures exert significant influence on the major constructs of e-leadership, which implies that an effective e-leadership strategy should consider cultural contexts seriously.  相似文献   
40.
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