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   553篇
  免费   53篇
各国政治   49篇
工人农民   16篇
世界政治   36篇
外交国际关系   47篇
法律   282篇
中国政治   4篇
政治理论   167篇
综合类   5篇
  2023年   7篇
  2022年   2篇
  2021年   8篇
  2020年   15篇
  2019年   21篇
  2018年   27篇
  2017年   38篇
  2016年   26篇
  2015年   28篇
  2014年   21篇
  2013年   99篇
  2012年   25篇
  2011年   24篇
  2010年   26篇
  2009年   18篇
  2008年   19篇
  2007年   12篇
  2006年   19篇
  2005年   8篇
  2004年   21篇
  2003年   10篇
  2002年   13篇
  2001年   7篇
  2000年   11篇
  1999年   5篇
  1998年   9篇
  1997年   8篇
  1996年   9篇
  1995年   4篇
  1994年   2篇
  1993年   6篇
  1992年   4篇
  1991年   8篇
  1990年   5篇
  1989年   5篇
  1988年   3篇
  1987年   4篇
  1986年   2篇
  1985年   4篇
  1984年   3篇
  1981年   3篇
  1980年   3篇
  1978年   3篇
  1977年   3篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
排序方式: 共有606条查询结果,搜索用时 31 毫秒
181.
182.
183.
184.
185.
186.
187.
188.
The management of needs and risks in personality disordered offender populations has become a focus for health and criminal justice services in the UK. Recent studies demonstrate the effectiveness of schema focussed therapy (SFT) for patients with borderline personality disorder. This study was an exploratory trial of the feasibility of implementing SFT in a population of patients with personality disorder in a high secure hospital in England. Preliminary evaluations of the effects of SFT were conducted to investigate whether those receiving SFT demonstrated significant improvements on measures of anger, impulsiveness, schemata and interpersonal style. No significant effects were evident although there was a significant increase in defectiveness/shame schema in the SFT group. Lack of effectiveness of SFT is likely due to the preliminary nature of this study. Future trials of SFT need to ensure comprehensive therapist preparation, control of TAU, bigger samples, address attrition and provide more intensive therapy.  相似文献   
189.

Objectives

We describe and explain how the findings from nonexperimental studies of the relationship between police force size and crime have changed over time.

Methods

We conduct a systematic review of 62 studies and 229 findings of police force size and crime, from 1971 through 2013. Only studies of U.S. policing and containing standard errors of estimates were included. Using the robust variance estimation technique for meta-analysis, we show the history of study findings and effect sizes. We look at the influence of statistical methods and units of analysis, and time period of studies’ data, as well as variation in police force size over time.

Results

Findings vary considerably over time. However, compared to research standards and in comparison to effect sizes calculated for police practices in other meta-analyses, the overall effect size for police force size on crime is negative, small, and not statistically significant. Changes in research methods and units of analysis cannot account for fluctuations in findings. Finally, there is extremely little variation in police force size per capita over time, making it difficult to estimate the relationship with reliability.

Conclusions

This line of research has exhausted its utility. Changing policing strategy is likely to have a greater impact on crime than adding more police.
  相似文献   
190.
The rise of fentanyl and fentanyl analogs in the drug supply pose serious threats to public health. Much of these compounds enter the United States through shipping routes. Here we provide a method for fentanyl screening and analysis that utilizes pressure-sensitive adhesive (PSA) lined paper to recover drug residues from parcel-related surfaces. The paper used is commercially available repositionable notes (also called post-it or sticky notes). From this paper, mass spectra were obtained by paper spray-mass spectrometry (PS-MS), where PSA paper served as both a sampling and analysis substrate. Seven fentanyl-related compounds were analyzed: fentanyl, 4-anilino-N-phenethylpiperidine (4-ANPP), N,1-diphenethyl-N-phenylpiperidin-4-amine (phenethyl-4-ANPP), valerylfentanyl, 4-fluoroisobutyrylfentanyl (4-FIBF), carfentanil, and p-fluorofentanyl. These compounds were recovered by PSA paper and identified by PS-MS from packaging tape and plastic at 50 ng and from cardboard and shipping labels at 100 ng. The impact of cutting agents on PS-MS analysis of fentanyl analogs was explored. No trends of analyte suppression were found at high concentrations of the cutting agents caffeine, diphenhydramine, and lidocaine when recovered from surfaces. A cartridge that required no precise cutting of PSA paper prior to sampling or analysis was evaluated for use in PS-MS for fentanyl screening. Recovery and detection of fentanyl from plastic sheeting was demonstrated with this cut-free cartridge. The cut-free cartridge showed somewhat less consistency and lower analyte signal than the standard cartridge, but performance was suitable for potential screening applications. In combining PSA surface sampling with PS-MS for drug screening, both sampling and detection of fentanyl-related compounds is simple, rapid, and low-cost.  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