全文获取类型
收费全文 | 26934篇 |
免费 | 794篇 |
专业分类
各国政治 | 1165篇 |
工人农民 | 1038篇 |
世界政治 | 2118篇 |
外交国际关系 | 924篇 |
法律 | 16241篇 |
中国共产党 | 2篇 |
中国政治 | 140篇 |
政治理论 | 5849篇 |
综合类 | 251篇 |
出版年
2020年 | 326篇 |
2019年 | 422篇 |
2018年 | 548篇 |
2017年 | 642篇 |
2016年 | 665篇 |
2015年 | 487篇 |
2014年 | 540篇 |
2013年 | 2699篇 |
2012年 | 720篇 |
2011年 | 734篇 |
2010年 | 569篇 |
2009年 | 652篇 |
2008年 | 705篇 |
2007年 | 749篇 |
2006年 | 688篇 |
2005年 | 622篇 |
2004年 | 621篇 |
2003年 | 635篇 |
2002年 | 609篇 |
2001年 | 1009篇 |
2000年 | 907篇 |
1999年 | 744篇 |
1998年 | 432篇 |
1997年 | 353篇 |
1996年 | 331篇 |
1995年 | 324篇 |
1994年 | 351篇 |
1993年 | 326篇 |
1992年 | 514篇 |
1991年 | 562篇 |
1990年 | 520篇 |
1989年 | 539篇 |
1988年 | 500篇 |
1987年 | 509篇 |
1986年 | 553篇 |
1985年 | 533篇 |
1984年 | 475篇 |
1983年 | 495篇 |
1982年 | 375篇 |
1981年 | 333篇 |
1980年 | 277篇 |
1979年 | 368篇 |
1978年 | 227篇 |
1977年 | 230篇 |
1976年 | 206篇 |
1975年 | 180篇 |
1974年 | 206篇 |
1973年 | 191篇 |
1972年 | 169篇 |
1971年 | 154篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
J Potter 《Journal - Forensic Science Society》1992,32(3):249-255
992.
A small experiment is described which uses databases of Afro-Caribbeans and Caucasians to establish the quality of information that might be given to an investigator about the ethnic group of the donor of an unknown crime stain. The results show that the technique can provide qualified indications, but categoric conclusions are not, in general, feasible. An appraisal is given of the technique within the operational context. 相似文献
993.
J E Allard 《Journal - Forensic Science Society》1992,32(1):49-58
Lorraine Benson's body was found beaten and strangled at Raynes Park, Surrey, in December 1988. Considering the possibility of linked offences, a murder squad was set up to work alongside a team already investigating a rape series in the Kingston area. A man's handkerchief left at a site a quarter of a mile from the murder scene was found to be stained with blood and saliva matching that of the victim. A DNA profile was obtained from a stain of nasal mucus on this handkerchief and found to match a suspect later arrested for an attempted rape in the same locality. Also of forensic interest were dust marks made by the zips of the victim's and defendant's coats and identification of the rope used for strangulation. 相似文献
994.
Jasmine Fardouly Natasha R Magson Carly J Johnco Ella L Oar Ronald M Rapee 《Journal of youth and adolescence》2018,47(7):1456-1468
Time spent on social media and making online comparisons with others may influence users’ mental health. This study examined links between parental control over the time their child spends on social media, preadolescents’ time spent browsing social media, preadolescents’ appearance comparisons on social media, and preadolescents’ appearance satisfaction, depressive symptoms, and life satisfaction. Preadolescent social media users (N?=?284, 49.1% female; aged 10–12) and one of their parents completed online surveys. Preadolescents, whose parents reported greater control over their child’s time on social media, reported better mental health. This relationship was mediated by preadolescents spending less time browsing and making fewer appearance comparisons on social media. Parental control over time spent on social media may be associated with benefits for mental health among preadolescents. 相似文献
995.
Christopher Cambron Rick Kosterman Richard F. Catalano Katarina Guttmannova J. David Hawkins 《Journal of youth and adolescence》2018,47(2):369-382
There is broad agreement that neighborhood contexts are important for adolescent development, but there is less consensus about their association with adolescent smoking and alcohol use. Few studies have examined associations between neighborhood socioeconomic contexts and smoking and alcohol use while also accounting for differences in family and peer risk factors for substance use. Data drawn from the Seattle Social Development Project (N?=?808), a gender-balanced (female?=?49%), multiethnic, theory-driven longitudinal study originating in Seattle, WA, were used to estimate trajectories of smoking and alcohol use from 5th to 9th grade. Time-varying measures of neighborhood socioeconomic, family, and peer factors were associated with smoking and alcohol use at each wave after accounting for average growth in smoking and alcohol use over time and demographic differences. Results indicated that living in more socioeconomically disadvantaged neighborhoods, lower family income, lower family general functioning, more permissive family smoking environments, and affiliation with deviant peers were independently associated with increased smoking. Lower family functioning, more permissive family alcohol use environments, and deviant peers were independently associated with increased alcohol use. The effect of neighborhood disadvantage on smoking was mediated by family income and deviant peers while the effect of neighborhood disadvantage on alcohol use was mediated by deviant peers alone. Family functioning and family substance use did not mediate associations between neighborhood disadvantage and smoking or alcohol use. The results highlight the importance of neighborhood, family, and peer factors in early adolescent smoking and alcohol use. Future studies should examine the unique association of neighborhood disadvantage with adolescent smoking net of family socioeconomics, functioning, and substance use, as well as peer affiliations. Better understanding of the role of contextual factors in early adolescent smoking and alcohol use can help bolster efforts to prevent both short and long harms from substance use. 相似文献
996.
In order to better understand why some children retaliate when they feel provoked and others do not, the present study identified “pacifistically-oriented” children who made negative interpretations in response to unambiguous provocations, yet did not endorse revenge goals, and compared them to “revenge-seeking” children who also made negative interpretations but did endorse revenge goals. Groups were identified based on seventh graders’ (N?=?367; 54.77% male; 22.89% racial/ethnic minority) responses to hypothetical situations in which a peer excluded and insulted them. Comparing these groups revealed that Pacifists endorsed relationship-maintaining goals and emotion regulation goals more highly than Revenge-Seekers. Revenge-Seekers reported more anger and endorsed beliefs about negative reciprocity and aggression being legitimate more highly than Pacifists. Additionally, Revenge-Seekers were more disrespect sensitive than were Pacifists, based on a measure of vigilance for signs of disrespect and expectations that others would disrespect them. Together these findings point to social-cognitive and emotion-related processes that may inhibit revenge-seeking in unambiguous provocation situations, even when children interpret the peer’s behavior quite negatively. 相似文献
997.
Most previous identity research has focused on relationships between identity synthesis, confusion, and psychosocial problems. However, these studies did not take into account Erikson’s notion of identity consolidation, that is, the dynamic interplay between identity synthesis and confusion. This study aimed to examine longitudinal relationships and the directionality of the effects between identity consolidation and psychosocial problems during adolescence, using two waves of longitudinal data from 793 Japanese adolescents (49.7% girls; ages 13–14 and 16–17 at Time 1). A bi-factor latent change model revealed that levels and changes in identity consolidation were negatively associated with levels and changes in psychosocial problems. Furthermore, a bi-factor cross-lagged effects model provided evidence that identity consolidation negatively predicted psychosocial problems, and vice versa. Our study facilitates a better understanding of the importance of identity consolidation in the relations between identity components and psychosocial problems. 相似文献
998.
In this paper we analyse possible effects of insurance on child labour. First, we develop a theoretical model that separates effects of insurance with and without a shock taking place. We then empirically test the hypotheses derived from the model by analysing the extension of a health insurance product in urban Hyderabad in Pakistan. Consistent with the theoretical model we develop in this paper, the reduction in child labour caused by the extension is largely due to an ex-ante feeling of protection as opposed to an ex-post shock-mitigation effect. 相似文献
999.
An increasing number of citizens change and adapt their party preferences during the electoral campaign. We analyze which short-term factors explain intra-campaign changes in voting preferences, focusing on the visibility and tone of news media reporting and party canvassing. Our analyses rely on an integrative data approach, linking data from media content analysis to public opinion data. This enables us to investigate the relative impact of news media reporting as well as party communication. Inherently, we overcome previously identified methodological problems in the study of communication effects on voting behavior. Our findings reveal that campaigns matter: Especially interpersonal party canvassing increases voters’ likelihood to change their voting preferences in favor of the respective party, whereas media effects are limited to quality news outlets and depend on individual voters’ party ambivalence. 相似文献
1000.
Rebecca J. Walter 《Housing Policy Debate》2018,28(4):553-571
Fair Market Rents (FMRs), calculated for an entire metropolitan region, are used to establish payment standards for the Housing Choice Voucher (HCV) program. In response to recent criticism that FMRs do not represent rent disparity and restrict households from moving to high-opportunity areas, a new rule introducing Small Area Fair Market Rents (SAFMRs) has been issued. SAFMRs are based on ZIP codes to reflect local market rents and increase the number of payment standards used to administer the HCV program. The purpose of this research is to determine whether the number of payment standards can be reduced by consolidating ZIP codes, while adhering to the primary objectives of the SAFMR rule. The ZIP code grouping process conducted offers one method for reducing the number of payment standards needed to implement the new rule; however, the rent analysis reveals the over- and underestimation of SAFMRs for some ZIP codes. 相似文献