全文获取类型
收费全文 | 25079篇 |
免费 | 782篇 |
国内免费 | 5篇 |
专业分类
各国政治 | 1011篇 |
工人农民 | 1040篇 |
世界政治 | 1698篇 |
外交国际关系 | 805篇 |
法律 | 15858篇 |
中国共产党 | 6篇 |
中国政治 | 195篇 |
政治理论 | 5008篇 |
综合类 | 245篇 |
出版年
2020年 | 306篇 |
2019年 | 391篇 |
2018年 | 483篇 |
2017年 | 575篇 |
2016年 | 575篇 |
2015年 | 431篇 |
2014年 | 452篇 |
2013年 | 2285篇 |
2012年 | 625篇 |
2011年 | 696篇 |
2010年 | 560篇 |
2009年 | 627篇 |
2008年 | 704篇 |
2007年 | 758篇 |
2006年 | 709篇 |
2005年 | 671篇 |
2004年 | 644篇 |
2003年 | 675篇 |
2002年 | 606篇 |
2001年 | 982篇 |
2000年 | 825篇 |
1999年 | 703篇 |
1998年 | 376篇 |
1997年 | 270篇 |
1996年 | 321篇 |
1995年 | 292篇 |
1994年 | 317篇 |
1993年 | 312篇 |
1992年 | 512篇 |
1991年 | 555篇 |
1990年 | 538篇 |
1989年 | 486篇 |
1988年 | 510篇 |
1987年 | 457篇 |
1986年 | 520篇 |
1985年 | 500篇 |
1984年 | 421篇 |
1983年 | 405篇 |
1982年 | 310篇 |
1981年 | 302篇 |
1980年 | 231篇 |
1979年 | 301篇 |
1978年 | 205篇 |
1977年 | 199篇 |
1976年 | 182篇 |
1975年 | 184篇 |
1974年 | 212篇 |
1973年 | 175篇 |
1972年 | 166篇 |
1969年 | 149篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
951.
Janet R. Cummings 《Journal of youth and adolescence》2014,43(7):1151-1162
Most adolescents with depressive disorders do not receive any mental health services, even though effective treatments exist. Although research has examined numerous individual-level factors associated with mental health service use among depressed adolescents, less is known about the role of contextual factors. This study examines the relationship between contextual-level socioeconomic status (SES) and clinic-based mental health counseling use among US adolescents with high depressive symptoms in urban and suburban areas. Data from the first two waves of the National Longitudinal Study of Adolescent Health (N = 1,133; 59 % female) were analyzed using multilevel logistic models in which adolescents were nested within counties. After controlling for individual-level predisposing, enabling, and need characteristics, as well as county racial/ethnic composition, county SES was positively associated with clinic-based counseling use among depressed youth. A one standard deviation increase in the county affluence index was associated with 43 % greater odds of receiving any clinical counseling services. Furthermore, the positive relationship between county affluence and clinical counseling use was no longer significant after controlling for the county supply of mental health specialist physicians. The results indicate that county residential context is a key correlate of mental health service use among depressed adolescents, such that those who live in lower SES counties with fewer mental health specialists are less likely to receive treatment. 相似文献
952.
953.
Netherlands International Law Review - Unlike the ICTY and ICTR Statutes, the Rome Statute of the ICC provides in Article 75 for various forms of court-ordered reparations for the victims of... 相似文献
954.
Mohammed A. Almazrouei M.Sc. Itiel E. Dror Ph.D. Ruth M. Morgan D.Phil. 《Journal of forensic sciences》2020,65(6):1968-1977
Although forensic examiners operate in a stressful environment, there is a lack of understanding about workplace stress and feedback. These organizational and human factors can potentially impact forensic science judgments. In this study, 150 practicing forensic examiners from one laboratory were surveyed about their experiences of workplace stress, and the explicit and implicit feedback they receive. Forensic examiners reported that their high stress levels originated more from workplace-related factors (management and/or supervision, backlogs, and the pressure to do many cases) than from personal related factors (family, medical, and/or financial). The findings showed that a few (8%) of the forensic examiners sometimes felt strong implicit feedback about what conclusions were expected from them and that some (14%) also strongly felt that they were more appreciated when they helped to solve a case (e.g., by reaching a “match” as opposed to an “inconclusive” conclusion). Differences were found when comparing workplace stress and feedback levels across three core forensic science fields (forensic biology, chemistry, and latent prints) and across career stages (early, mid, and late). Gaining insights into the stress factors within a workplace and explicit and implicit feedback has implications for developing policies to improve the well-being, motivation, and performance of forensic examiners. 相似文献
955.
Research indicates that voters are not particularly effective at removing corrupt politicians from office, in part because voters make decisions on the basis of many competing factors. Party leaders are much more single-minded than voters and will choose to deselect implicated legislators if it means maintaining a positive party reputation and improving the odds of winning a legislative majority. We examine renominations to Italy’s legislature in two periods marked by corruption. We compare these renomination patterns with those from the prior legislature, when corruption lacked political salience. Our analysis shows that incumbent renominations are negatively associated with the number of press mentions that link the incumbent to corruption—but only when corruption is salient to the public. Our study highlights the importance of party leaders in forcing malfeasant legislators out of office—and reducing corruption—and redirects attention from voters to political elites as a critical channel in enforcing democratic accountability. 相似文献
956.
Patrick Megan E. Rhew Isaac C. Duckworth Jennifer C. Lewis Melissa A. Abdallah Devon Alisa Lee Christine M. 《Journal of youth and adolescence》2020,49(4):869-880
Journal of Youth and Adolescence - Young adults experience social role transitions across multiple life domains, and a deeper understanding of the ways in which these simultaneous transition... 相似文献
957.
Simone Rosenblum Rebekah L. St. Clair Kimberley R. Isett Reagan Johnson 《Australian Journal of Public Administration》2020,79(4):407-425
Journal editors serve as gatekeepers of knowledge, a role critical to preserving the quality and standards of good research. Some scholars have questioned whether editors have taken advantage of their position to publish their own work. To understand the extent to which editors of public administration journals self-publish, we examined publishing patterns over a 20-year period. We collected the names of editors from the mastheads of 13 generalist public administration journals from 1997 to 2016 and used data indexed from Web of Science to look at articles published in those journals during the same time. We found that while self-publishing behaviour is not common across the entire field, it is a trend for certain journals and individuals. We also found the practice of self-publishing is influenced by whether an individual served in a primary editorial role (e.g., editor-in-chief), length of editorial service, and overall scholarly productivity. We discuss appropriateness and ethical implications of the practice. 相似文献
958.
Sierra F. Kaszubinski B.Sc. Jennifer L. Pechal Ph.D. Carl J. Schmidt M.D. Heather R. Jordan Ph.D. Mark E. Benbow Ph.D. Mariah H. Meek Ph.D. 《Journal of forensic sciences》2020,65(2):513-525
Microbial communities have potential evidential utility for forensic applications. However, bioinformatic analysis of high-throughput sequencing data varies widely among laboratories. These differences can potentially affect microbial community composition and downstream analyses. To illustrate the importance of standardizing methodology, we compared analyses of postmortem microbiome samples using several bioinformatic pipelines, varying minimum library size or minimum number of sequences per sample, and sample size. Using the same input sequence data, we found that three open-source bioinformatic pipelines, MG-RAST, mothur, and QIIME2, had significant differences in relative abundance, alpha-diversity, and beta-diversity, despite the same input data. Increasing minimum library size and sample size increased the number of low-abundant and infrequent taxa detected. Our results show that bioinformatic pipeline and parameter choice affect results in important ways. Given the growing potential application of forensic microbiology to the criminal justice system, continued research on standardizing computational methodology will be important for downstream applications. 相似文献
959.
Terezie Cernosek B.S. Kevin E. Eckert M.Sc. David O. Carter Ph.D. Katelynn A. Perrault Ph.D. 《Journal of forensic sciences》2020,65(1):134-143
Volatile organic compounds (VOCs) are by-products of cadaveric decomposition and are responsible for the odor associated with decomposing remains. The direct link between VOC production and individual postmortem microbes has not been well characterized experimentally. The purpose of this study was to profile VOCs released from three postmortem bacterial isolates (Bacillus subtilis, Ignatzschineria indica, I. ureiclastica) using solid-phase microextraction arrow (SPME Arrow) and gas chromatography–mass spectrometry (GC-MS). Species were inoculated in headspace vials on Standard Nutrient Agar and monitored over 5 days at 24°C. Each species exhibited a different VOC profile that included common decomposition VOCs. VOCs exhibited upward or downward temporal trends over time. Ignatzschineria indica produced a large amount of dimethyldisulfide. Other compounds of interest included alcohols, aldehydes, aromatics, and ketones. This provides foundational data to link decomposition odor with specific postmortem microbes to improve understanding of underlying mechanisms for decomposition VOC production. 相似文献
960.
Jeri D. Ropero-Miller Ph.D. Hope M. Smiley-McDonald Ph.D. Stephanie A. Zimmer Ph.D. Katherine M. Bollinger M.S. 《Journal of forensic sciences》2020,65(2):544-549
In 2007, the Bureau of Justice Statistics reported on 2004 data collected from the Census of Medical Examiner and Coroner Offices (CMEC). The CMEC was one of the first comprehensive reports on the state of the medicolegal death investigation system in the United States and included information on administration, expenditure, workload, specialized death investigations, records and evidence retention, and resources. However, the report did not include responses on questions that were related to toxicology such as specimen retention and type of testing. The purpose of this publication is to provide the community with toxicology laboratory-specific responses from nearly 2000 medical examiner and coroner (MEC) offices. Data obtained from a BJS CMEC public use dataset for any remaining information that was not reported in the 2007 BJS report were evaluated specific to the operation of toxicology laboratories within a MEC office or specific to toxicology testing. The CMEC includes information on average operating budget for MEC offices with internal or external toxicology services, budget for toxicology/microbiology services, respondents’ routine uses of toxicology analysis, toxicology specimen retention time, average turnaround times, use of computerized information management systems, and participation in federal data collections. These historical data begin to address the present state of our nation’s toxicology laboratories within the medicolegal death investigation system and their preparedness for the current drug overdose epidemic. 相似文献