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   5239篇
  免费   36篇
各国政治   171篇
工人农民   42篇
世界政治   780篇
外交国际关系   470篇
法律   3127篇
中国共产党   74篇
中国政治   237篇
政治理论   289篇
综合类   85篇
  2021年   25篇
  2018年   22篇
  2016年   17篇
  2015年   20篇
  2014年   108篇
  2013年   28篇
  2012年   394篇
  2011年   354篇
  2010年   112篇
  2009年   116篇
  2008年   343篇
  2007年   349篇
  2006年   319篇
  2005年   291篇
  2004年   290篇
  2003年   296篇
  2002年   323篇
  2001年   220篇
  2000年   259篇
  1999年   103篇
  1998年   62篇
  1997年   43篇
  1996年   35篇
  1995年   43篇
  1994年   78篇
  1993年   62篇
  1992年   54篇
  1991年   52篇
  1990年   38篇
  1989年   30篇
  1988年   117篇
  1987年   30篇
  1986年   35篇
  1985年   37篇
  1984年   28篇
  1983年   31篇
  1982年   22篇
  1981年   39篇
  1980年   44篇
  1979年   39篇
  1978年   21篇
  1977年   42篇
  1976年   35篇
  1973年   15篇
  1964年   27篇
  1963年   24篇
  1962年   40篇
  1961年   18篇
  1960年   22篇
  1959年   29篇
排序方式: 共有5275条查询结果,搜索用时 15 毫秒
941.
This study describes an innovative application of a well-established method of age determination. The conventional method of aspartic acid racemization (AAR) is based on estimation of the d-l-aspartic acid ratio in slow turnover tissues, such as tooth tissue, to reflect the age of an individual. This method has been recently applied to age estimation in forensic investigations, and is also widely used for archeological dating of fossils. We suggest that the aspartic acid racemization method could be applied to a significant, although unresolved, forensic issue: that of bloodstain dating. Standard kinetic experiments were used to describe the characteristics of the racemization reaction in bloodstains, which were then employed to estimate the age of various samples. The soluble protein fraction of a bloodstain produced a stronger correlation between elapsed time and d-aspartic acid content than total amino acid fractions. According to our preliminary results, the time lapse after the creation of a bloodstain can be determined ex vivo by measuring the extent of aspartic acid racemization. Our analysis highlights the need for further study into the preservation and composition of bloodstains to assist in further development of this pioneering application.  相似文献   
942.
Through theoretical analysis and introduction of some empirical parameters, the relationship between post-braking-distance and throw distance was studied concentratedly. Here, the post-braking-distance is the distance a vehicle will travel from the impact position to when it comes to a complete stop. Two useful formulas which are meaningful in vehicle-pedestrian accident reconstruction were finally obtained. The first one can be used to calculate impact speed according to throw distance, while the other one can describe the relationship between post-braking-distance and throw distance. Their feasibility has been validated by comparing with other scholars' empirical formulas and simulation results of software Pc-Crash, respectively. The relationship between post-braking-distance and throw distance has very bright application perspective in vehicle-pedestrian accident reconstruction such as helping policemen obtain more useful evidences, validating credibility of the throw distance, judging whether the vehicle is fully braked or not, determining the impact position etc. Finally its application was demonstrated by three cases, in which the impact speed was also calculated. All results until now have shown that conclusions obtained in this article are feasible and helpful in vehicle-pedestrian accident reconstruction.  相似文献   
943.
The succession of insects on pig carrion was monitored in spring, summer and autumn, in three forest types and 2 years in Western Poland (Central Europe). In most forensically useful taxa, significant differences between seasons, forests and years in time of appearance on carrion were found. The lowest values of appearance time were recorded in summer and the highest in spring. In alder forest insects appeared on carcasses significantly earlier than in pine-oak forest and hornbeam-oak forest. In summer periods of insect presence on carrion were significantly shorter than in spring and autumn. In most taxa no significant effect of forest type or year on length of the presence period was found. In all seasons assemblages of adult taxa were clearly more aggregated than assemblages of larval taxa. Sequence of insects' appearance on carcasses was very similar in different seasons, forests and years. General seasonal models of insect succession on carrion are proposed for forests of Central Europe. Data on appearance time and length of the presence period in particular seasons, forests and years are presented for forensically useful taxa. Implications for methods of PMI estimation (particularly the succession-based method) are discussed.  相似文献   
944.
945.
946.
This longitudinal population-based study examined pathways to nonsuicidal self-harm (NSSH) in relation to childhood sexual abuse (CSA), assault victimization in early adulthood, posttraumatic stress disorder symptomatology (PTSD), and other mental disorders. At age 21, 476 men and 455 women completed interviews on assault victimization, PTSD, and other mental disorders. At age 26, they completed independent interviews on self-harm and childhood sexual abuse (CSA). Multivariate logistic regression analyses were conducted to determine predictors for NSSH at age 26. For men, anxiety and depressive disorders at age 21 were the only significant predictors of NSSH at age 26. For women, victimization, PTSD, and other anxiety disorders at age 21 all significantly predicted NSSH. CSA predicted later NSSH only indirectly, by increasing the risk of anxiety disorders among men and of assault victimization among women. In conclusion, pathways to nonsuicidal self-harm differed by sex. For women there were direct links with assault victimization and PTSD in early adulthood, whereas for men only internalizing disorders predicted future NSSH.  相似文献   
947.
This study aims to provide preliminary findings on the validity of Child Abuse Potential Inventory (CAP Inventory) on Turkish sample of 23 abuser and 47 nonabuser parents. To investigate validity in two groups, Minnesota Multiphasic Personality Inventory (MMPI) Psychopathic Deviate (MMPI-PD) scale is also used along with CAP. The results show that, with the 200.5 cutoff point, which is the average score of the whole Turkish sample, Abuse Scale correctly classified 83% of the participants in the abuse group and 78.8% of the participants in the control group, which gives 21.2% false-positive result. MMPI-PD to all group and Pearson correlation coefficient analysis is found to be significant for both groups. These results show us high reliability and validity of the abuse scale for Turkey.  相似文献   
948.
949.
The Safe Start demonstration projects, funded by the Office of Juvenile Justice and Delinquency Prevention (OJJDP) under the first phase of the Safe Start initiative, are primarily designed to influence change at the systems or macrolevels to reduce the incidence of and impact of exposure to violence for children aged birth to 6 years; direct services are also provided to young children and their families who were exposed to violence. The data presented in this article come from 10 communities that submitted data regarding the characteristics of young children exposed to violence to OJJDP. These data represent families who are typically not represented in the databases of state child protective services programs but instead have been identified by domestic violence advocates, early care and education providers, family members, court personnel, police, and other social service personnel as families with young children in need of intervention due to violence exposure.The purpose of this article is to describe the characteristics of young children and their parents who seek help for psychosocial problems related to exposure to family and community violence. Results indicate that one quarter of the children and nearly half of their parents evidenced clinical levels of stress, suggesting the need to intervene at the family level as well as at the individual level when working with young children exposed to violence. The information presented, including the extent of exposure to violence, the multiple types of violence to which children are exposed, the impact of this exposure on young children and their families, and the multiple ways in which families exposed to violence come to the attention of service providers is useful for policy makers and service providers who are interested in breaking the cycle of violence by meeting the needs of the children exposed to violence and their families.  相似文献   
950.
Stalking has increasingly been the subject of legislation and research in the past 20 years. Within intimate partner violence, the context where it is most likely to occur, stalking predicts both greater danger and greater distress for the victim. However, research shows that practitioners are often unsure how to address stalking, and that the remedies available may not be effective. This longitudinal exploration of stalking focused on the experience of victims of intimate partner stalking and was conducted by Safe Horizon, an organization providing assistance to victims of violence and abuse in New York City. The sample of 82 women was interviewed monthly over 7 months, and the data were analyzed using growth curve models. We found that stalking decreased over time at a marginally significant level, and that change in stalking varied among participants. Perceived safety followed a similar pattern, increasing but not significantly, while stalking-related distress decreased significantly. The slopes of these variables were correlated, such that as stalking frequency decreased, perceived safety increased and distress decreased. Help-seeking was greater from court sources than victim services over the course of the study, but neither help source was related to a significant decrease in the stalking trajectory. According to victim report, orders of protection (OP) were helpful at some points and not at others. Implications of these results for offering victim-centered services are discussed.  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