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   1103篇
  免费   44篇
各国政治   83篇
工人农民   78篇
世界政治   92篇
外交国际关系   72篇
法律   538篇
中国政治   12篇
政治理论   258篇
综合类   14篇
  2023年   7篇
  2022年   6篇
  2021年   12篇
  2020年   26篇
  2019年   32篇
  2018年   48篇
  2017年   55篇
  2016年   51篇
  2015年   30篇
  2014年   34篇
  2013年   219篇
  2012年   35篇
  2011年   53篇
  2010年   45篇
  2009年   39篇
  2008年   44篇
  2007年   42篇
  2006年   39篇
  2005年   37篇
  2004年   29篇
  2003年   16篇
  2002年   30篇
  2001年   16篇
  2000年   14篇
  1999年   16篇
  1998年   15篇
  1997年   13篇
  1996年   10篇
  1995年   10篇
  1994年   12篇
  1993年   14篇
  1991年   12篇
  1990年   10篇
  1989年   9篇
  1988年   3篇
  1987年   4篇
  1986年   4篇
  1985年   6篇
  1984年   8篇
  1983年   7篇
  1982年   8篇
  1981年   3篇
  1980年   3篇
  1977年   2篇
  1976年   2篇
  1974年   4篇
  1973年   3篇
  1967年   1篇
  1966年   3篇
  1939年   1篇
排序方式: 共有1147条查询结果,搜索用时 15 毫秒
161.
162.
The changing nature of the transition to adulthood in western societies, such as the United States, may be extending the length of time parents are engaged in “parenting” activities. However, little is known about different approaches parents take in their interactions with their emerging-adult children. Hence, this study attempted to identify different clusters of parents based on the extent to which they exhibited both extremes of control (psychological control, punishment, verbal hostility, indulgence) and responsiveness (knowledge, warmth, induction, autonomy granting), and to examine how combinations of parenting were related to emerging adult children’s relational and individual outcomes (e.g. parent–child relationship quality, drinking, self-worth, depression). The data were collected from 403 emerging adults (M age = 19.89, SD = 1.78, range = 18–26, 62% female) and at least one of their parents (287 fathers and 317 mothers). Eighty-four percent of participants reported being European American, 6% Asian American, 4% African American, 3% Latino, and 4% reported being of other ethnicities. Data were analyzed using hierarchical cluster analysis, separately for mothers and fathers, and identified three similar clusters of parents which we labeled as uninvolved (low on all aspects of parenting), controlling-indulgent (high on both extremes of control and low on all aspects of responsiveness), and authoritative (high on responsiveness and low on control). A fourth cluster was identified for both mothers and fathers and was labeled as inconsistent for mothers (mothers were above the mean on both extremes of control and on responsiveness) and average for fathers (fathers were at the mean on all eight aspects of parenting). The discussion focuses on how each of these clusters effectively distinguished between child outcomes.  相似文献   
163.
164.
Accurate DNA quantification is essential for optimizing DNA testing and minimizing sample consumption. Real-time quantitative polymerase chain reaction (qPCR) assays have been published for human and canine nuclear DNA, and the need for quantifying other forensically important species was evident. Following the strategy employed for the canine qPCR assay, we developed individual assays to accurately quantify feline, bovine, equine, and cervid nuclear DNA. Each TaqMan-based assay incorporates a genus-specific probe targeting the Melanocortin-1 Receptor gene and includes a piece of synthetic DNA that acts as an internal PCR control for detecting inhibition. Developmental validations were carried out following the revised guidelines of the Scientific Working Group on DNA Analysis Methods with modifications necessary for validation of nonhuman qPCR assays. All assays demonstrated the specificity, sensitivity, stability, reproducibility, accuracy, and precision required for forensic casework. The application of these assays to animal forensic DNA analysis has both conserved laboratory resources and improved genotyping results.  相似文献   
165.
Approximately 81.7 million cats are in 37.5 million U.S. households. Shed fur can be criminal evidence because of transfer to victims, suspects, and/or their belongings. To improve cat hairs as forensic evidence, the mtDNA control region from single hairs, with and without root tags, was sequenced. A dataset of a 402-bp control region segment from 174 random-bred cats representing four U.S. geographic areas was generated to determine the informativeness of the mtDNA region. Thirty-two mtDNA mitotypes were observed ranging in frequencies from 0.6-27%. Four common types occurred in all populations. Low heteroplasmy, 1.7%, was determined. Unique mitotypes were found in 18 individuals, 10.3% of the population studied. The calculated discrimination power implied that 8.3 of 10 randomly selected individuals can be excluded by this region. The genetic characteristics of the region and the generated dataset support the use of this cat mtDNA region in forensic applications.  相似文献   
166.
Despite the growing research in the area of stalking, the focus has been on adults who engage in this behavior. Unfortunately, almost no studies investigate the prevalence of this behavior in adolescents. Two cases are presented demonstrating not only that stalking occurs during the period of adolescence, but also that there is a significant difference in the motivation underlying this behavior that can be classified similarly to that of adult stalkers. Further, a suggested classification based on these two cases as well as our experience with other juveniles who have exhibited stalking behaviors is proposed. The first case involves a narcissistic youth who also possesses psychopathic traits, while the second involves a lonely, severely socially awkward teen. Juvenile stalking is a societal problem that has not yet garnered the attention it deserves, and all systems that deal with juvenile delinquency (juvenile court, law enforcement, and mental health personnel) as well as the school system must be educated to the prevalence and severity of this yet-to-be-recognized problem.  相似文献   
167.

Purpose

Gottfredson and Hirschi, in A General Theory of Crime, argue that the primary source of self-control is parental socialization. Specifically, parents who fail to supervise their children, to recognize their child's deviant behavior, and to punish such behavior are more likely to raise children with lower levels of self-control. Recent empirical research, however, has broadened the explanatory factors to include sources within schools, neighborhoods, and individual factors as significant contributors to the development of self-control. This study proposes that maternal smoking during pregnancy places additional limits on the development of self-control.

Methods

Using a subsample of the National Longitudinal Study of Youth (N = 542), we provide a comprehensive investigation of the variety of sources of self-control to include both individual and environmental covariates.

Results

Results indicate that maternal smoking during pregnancy significantly impacts the development of self-control net of parental, neighborhood, and school socialization. We also found that individual sources of self-control significantly vary across race and neighborhood context.

Conclusions

The sources of self-control are more complex than socialization from parents, schools, and within neighborhoods occurring in childhood and adolescence.  相似文献   
168.
A range of protein stains were utilised for the enhancement of footwear impressions on a variety of fabric types of different colours with blood as a contaminant. A semi-automated stamping device was used to deliver test impressions at a set force to minimise the variability between impressions; multiple impressions were produced and enhanced by each reagent to determine the repeatability of the enhancement. Results indicated that while most protein stains used in this study successfully enhanced impressions in blood on light coloured fabrics, background staining caused interference on natural fabrics. Enhancement on dark coloured fabrics was only achieved using fluorescent protein stains, as non-fluorescent protein stains provided poor contrast.A further comparison was performed with commercially available protein staining solutions and solutions prepared within the laboratory from the appropriate chemicals. Both solutions performed equally well, though it is recommended to use freshly prepared solutions whenever possible.  相似文献   
169.
Purpose. Alcohol‐related violence is a serious problem and treatments for high‐risk individuals need to be developed. Classification helps to route people into appropriate treatments. Drawing on animal research, we define alcohol‐related violence in relation to ultimate goals. We propose three types of violence: (1) violence in the pursuit of material goals, (2) violence in pursuit of social dominance goals, and (3) violence as defence in response to threat. The aim is to explore factors that we expect to relate to this tripartite typology, with the aim of providing a preliminary validation. Method. Participants were 149 young male prisoners who had committed an offence of violence that was alcohol related. Semi‐structured interviews elicited information about the offence that enabled classification into one of the three types. Differences between groups were examined at the event level – level of violence during the offence and alcohol consumption before the offence – and at group level – trait aggression, trait anxiety, anger control, and alcohol–aggression outcome expectancies. Results. No differences were found in levels of violence or alcohol consumption. Those whose violence was in the pursuit of material goals were high on trait aggression, trait anger, trait anxiety, and anger suppression. Those who used violence in the pursuit of social dominance showed high trait aggression and trait anger. Those whose violence was a defence in response to threat showed lower trait aggression and trait anger. Conclusion. The findings are discussed in relation to differential group profiles and treatment needs.  相似文献   
170.
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