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   2061篇
  免费   529篇
各国政治   123篇
工人农民   27篇
世界政治   48篇
外交国际关系   93篇
法律   1321篇
中国共产党   45篇
中国政治   113篇
政治理论   595篇
综合类   225篇
  2023年   5篇
  2022年   6篇
  2021年   52篇
  2020年   61篇
  2019年   177篇
  2018年   155篇
  2017年   125篇
  2016年   152篇
  2015年   138篇
  2014年   156篇
  2013年   373篇
  2012年   251篇
  2011年   168篇
  2010年   121篇
  2009年   90篇
  2008年   98篇
  2007年   108篇
  2006年   117篇
  2005年   57篇
  2004年   50篇
  2003年   67篇
  2002年   25篇
  2001年   22篇
  2000年   7篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1991年   1篇
  1990年   3篇
排序方式: 共有2590条查询结果,搜索用时 15 毫秒
241.
Abstract: Consumer complaints received by the U.S. Food and Drug Administration in August 2010 about raw organic almonds tasting “bitter” opened an investigation into the presence of bitter almonds in the imported product. Bitter almonds (Prunus amygdalus) contain the cyanogenic glucoside amygdalin, which hydrolyzes to produce cyanide. Ultraviolet–visible spectrophotometry was used to detect and quantitate cyanide, and liquid chromatography‐mass spectrometry was utilized to detect amygdalin in the submitted samples. Control bitter almonds were found to contain 1.4 mg cyanide/g and an estimated level of 20–25 mg amygdalin/g. The questioned samples contained between 14 and 42 μg cyanide/g and were positive for the presence of amygdalin. Sweet almonds were found to be negative for both compounds, at levels of detection of 4 μg cyanide/g and 200 μg amygdalin/g.  相似文献   
242.
Abstract: This study provides forensic search teams with systematic geophysical monitoring data over simulated clandestine graves for comparison to active cases. Simulated “wrapped” and “naked” burials were created. Multigeophysical surveys were collected over a 3‐year monitoring period. Bulk ground resistivity, electrical resistivity imaging, multifrequency ground‐penetrating radar (GPR), and grave and background “soil‐water” conductivity data were collected. Resistivity surveys revealed the naked burial had consistently low‐resistivity anomalies, whereas the wrapped burial had small, varying high‐resistivity anomalies. GPR 110‐ to 900‐MHz frequency surveys showed the wrapped burial could be detected throughout, with the “naked” burial mostly resolved. Two hundred and twenty‐five megahertz frequency GPR data were optimal. “Soil‐water” analyses showed rapidly increasing (year 1), slowly increasing (year 2), and decreasing (year 3) conductivity values. Results suggest resistivity and GPR surveys should be collected if target “wrapping” is unknown, with winter to spring surveys optimal. Resistivity surveys should be collected in clay‐rich soils.  相似文献   
243.
Abstract: The question of whether the insect repellent N,N‐Diethyl‐meta‐toluamide (DEET) affected fly attraction, oviposition, and larval development was investigated; in part, to determine whether the common habit of wearing DEET as a repellent could affect the rate of human decomposition. Experiments using pig surrogates of human decedents were carried out in a rural environment. Dead piglets were sprayed with DEET, and fly behavior, colonization levels, and maggot development were compared with those in nonsprayed controls. Piglets treated with DEET experienced significant delays in fly visitation and oviposition and delayed appearance of each larval instar, as well as reduced total larval numbers (p < 0.01 for all variables), with subsequently reduced decomposition (p < 0.05). Such changes in fly behavior and larval population development would significantly impact the estimation of the period following the death from entomological evidence in decedents wearing DEET at the time of their death.  相似文献   
244.
《Justice Quarterly》2012,29(2):411-417

Prior research into the effects of racial diversity on workplace relationships has demonstrated that white workers prefer to work in and with groups which are also composed of white workers. Using structural equation models, we tested whether higher levels of racial diversity, measured as social distance from coworkers and inmates, were associated with lower evaluations of organizational commitment, teamwork among coworkers, and efficacy in dealing with inmates. We found the expected negative effects of racial diversity on white male correctional workers for organizational commitment, but not for teamwork and efficacy. For minority male correctional workers, racial diversity did not affect organizational commitment, teamwork, or efficacy.  相似文献   
245.
《Justice Quarterly》2012,29(1):147-162
The errors associated with measuring the number of militia and patriot groups may cast doubt on conclusions drawn from prior studies of the spatial variation of these movements. Most studies of militias have been qualitative investigations of a single group, state, or region. A growing number of studies, however, have used quantitative techniques to assess the hypothesis that the number of militia groups by state covaries with structural and cultural forces. We outline a number of concerns with the validity of the counts, conducted by the Anti‐Defamation League and the Southern Poverty Law Center, used by these studies. We re‐estimate models from previous studies using the four alternative measures of these groups employed in prior studies. We find that many inferences drawn for identical theoretical models differ based upon the measure used. These discrepancies apply not simply to tangential control variables but to indicators of key theoretical constructs. In other words, the decision as to whether or not a particular theoretical framework receives empirical support often depends upon which measure of the dependent variable is used. This suggests that the inconsistent findings in prior research may be due to measurement error and makes it difficult to assess the validity of the conclusions drawn from these studies. It is important to be aware of these weaknesses since scholars studying political crimes and related phenomena often use information from similar sources, making this specific example relevant to a more general area of research.  相似文献   
246.
《Justice Quarterly》2012,29(4):695-715
Prior research on law enforcement and court system actions suggests that offender demeanor influences practitioner decision making. However, few studies have examined a key implication of this body of work—namely, criminogenic factors associated not only with offending but also with demeanor may result in a greater likelihood of contact with and formal processing by law enforcement and the courts. Using data from the National Longitudinal Study of Adolescent Health, we test the hypothesis that low self‐control, which is associated with a range of characteristics that might influence practitioner perceptions of individual offenders’ demeanors, will predict greater contact and formal processing. Briefly, we found that low self‐control was consistently related to criminal justice system involvement as measured by police contacts, arrests, age at first police contact, and arrest onset. The implications of the findings for theory and research are discussed.  相似文献   
247.
《Justice Quarterly》2012,29(4):644-669
A prominent perspective in the gang literature suggests that gang member involvement in drug selling does not necessarily increase violent behavior. In addition it is unclear from previous research whether neighborhood disadvantage strengthens that relationship. We address these issues by testing hypotheses regarding the confluence of neighborhood disadvantage, gang membership, drug selling, and violent behavior. A three‐level hierarchical model is estimated from the first five waves of the 1997 National Longitudinal Survey of Youth, matched with block‐group characteristics from the 2000 U.S. Census. Results indicate that (1) gang members who sell drugs are significantly more violent than gang members that don’t sell drugs and drug sellers that don’t belong to gangs; (2) drug sellers that don’t belong to gangs and gang members who don’t sell drugs engage in comparable levels of violence; and (3) an increase in neighborhood disadvantaged intensifies the effect of gang membership on violence, especially among gang members that sell drugs.  相似文献   
248.
《Justice Quarterly》2012,29(2):221-246
Restorative justice processes, and family group conferences in particular, have become increasingly common in justice system practices across the globe. There has also been significant scholarly interest. Yet, with several notable exceptions, much of the research has been characterized by relatively weak designs, and questions related to the impact of family group conferences on re‐offending remain unanswered. This research is intended to begin to address these issues. The study is based on an experiment conducted in Indianapolis, Indiana whereby young, first‐time‐offending youths were randomly assigned to either a family group conference or one of a number of court‐ordered diversion programs. Nearly 800 youths participated in the experiment, and the cases were tracked for 24 months following their initial arrest. Survival analysis techniques were used to compare prevalence patterns of re‐offending among the treatment and control groups. The results indicated a significant difference between the two groups with the control group experiencing higher rates of failure (re‐offending). The differences were most pronounced during the period of 3–8 months following the initial arrest. Incidence rates were also compared. Assignment to the treatment group was negatively related to incidence of offending. Given the consistent finding of victim benefits in restorative justice processes, the results suggest that conferences hold promise as an effective intervention, at least for young first‐time offenders, and warrant continued experimentation.  相似文献   
249.
《Justice Quarterly》2012,29(2):258-286
The potential for veterans to end up in the criminal justice system as a result of physical and psychological problems that may be combat‐related has generated much interest, illustrated most recently by the development of specialized veterans’ courts. However, little is known about how often veterans are arrested and incarcerated, the nature of their problems, or the extent to which their military service has contributed to their criminality. Using interview data from 2,102 arrestees booked in Maricopa County (AZ) during 2009, this paper examines the problems and prior experiences of arrested military veterans and compares veteran and non‐veteran arrestees along a range of measures. Results indicate that veterans comprise 6.3% of the arrestee population, and that more than 50% of veterans report suffering from at least one combat‐related problem including physical injury, post‐traumatic stress disorder (PTSD), other mental health problems, and substance abuse. Multivariate analysis indicates that veteran arrestees differ from non‐veterans on a number of key measures, most notably more frequent arrests for violent offenses and greater use of crack cocaine and opiates. The paper concludes with a discussion of implications for the potential link between military service and criminality as well as for criminal justice policy and practice.  相似文献   
250.
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