全文获取类型
收费全文 | 3573篇 |
免费 | 156篇 |
专业分类
各国政治 | 210篇 |
工人农民 | 99篇 |
世界政治 | 350篇 |
外交国际关系 | 260篇 |
法律 | 1476篇 |
中国共产党 | 2篇 |
中国政治 | 37篇 |
政治理论 | 1253篇 |
综合类 | 42篇 |
出版年
2021年 | 29篇 |
2020年 | 44篇 |
2019年 | 70篇 |
2018年 | 106篇 |
2017年 | 115篇 |
2016年 | 113篇 |
2015年 | 76篇 |
2014年 | 94篇 |
2013年 | 597篇 |
2012年 | 77篇 |
2011年 | 105篇 |
2010年 | 96篇 |
2009年 | 109篇 |
2008年 | 104篇 |
2007年 | 100篇 |
2006年 | 108篇 |
2005年 | 115篇 |
2004年 | 103篇 |
2003年 | 95篇 |
2002年 | 116篇 |
2001年 | 76篇 |
2000年 | 77篇 |
1999年 | 65篇 |
1998年 | 59篇 |
1997年 | 60篇 |
1996年 | 38篇 |
1995年 | 51篇 |
1994年 | 58篇 |
1993年 | 52篇 |
1992年 | 40篇 |
1991年 | 53篇 |
1990年 | 35篇 |
1989年 | 50篇 |
1988年 | 29篇 |
1987年 | 36篇 |
1986年 | 40篇 |
1985年 | 41篇 |
1984年 | 31篇 |
1983年 | 43篇 |
1982年 | 41篇 |
1981年 | 50篇 |
1980年 | 36篇 |
1979年 | 39篇 |
1978年 | 35篇 |
1977年 | 19篇 |
1976年 | 32篇 |
1975年 | 17篇 |
1974年 | 19篇 |
1973年 | 20篇 |
1969年 | 17篇 |
排序方式: 共有3729条查询结果,搜索用时 15 毫秒
901.
The effect of dose-death interval and tissue distribution on the detection of meperidine in selected skeletal tissues was examined using a rapid microwave-assisted extraction (MAE) methodology. Rats (n=14) were dosed with 0 (n=2) or 30 mg/kg (n=12) meperidine (i.p.). Drug-positive rats were sacrificed with CO(2) after 20, 30, 90 and 150 min (n=3 per group). Heart blood was collected immediately after death. Tibiae were excised and frozen for further analysis. The remaining carcasses were allowed to decompose outside in secured cages to the point of complete skeletonization in a rural Northern Ontario location during the late summer months. Vertebrae and pelvi were collected for each animal. Tibial marrow was homogenized in 3 mL PB6 (phosphate buffer, 0.1M, pH 6). Fresh tibiae, and decomposed vertebrae and pelvi were cleaned in PB8.5 (phosphate buffer, 0.1M, pH 8.5) and sonicated to remove remaining soft tissue. Samples of dried, ground bone (0.5-1g) suspended in 2 mL PB6 were then irradiated in a domestic microwave oven (1100 W) at atmospheric pressure for 15 min. Samples of vertebral bone (1g) were also extracted by passive incubation in methanol (3 mL, 50°C, 72 h). All supernatants then underwent solid-phase extraction and analysis by GC/MS, using electron impact ionization in the Selected Ion Monitoring (SIM) mode. Mean GC/MS responses for each tissue type were negatively correlated with dose-death interval, with correlation coefficients ranging from -0.32 to -0.87. Analysis of variance showed dose-death interval to be a main effect (p<0.05) with respect to GC/MS response for blood, marrow, tibial epiphyses prepared by MAE, and vertebral bone prepared by passive extraction, but not for tibial diaphyses, pelvi or vertebrae prepared by MAE. Overall, MAE is advantageous as a rapid extraction tool for screening purposes in skeletal tissues, but assignment of significance to quantitative expressions of skeletal drug concentrations is complex and should be approached with caution. 相似文献
902.
Neumann C Mateos-Garcia I Langenburg G Kostroski J Skerrett JE Koolen M 《Forensic science international》2011,212(1-3):32-46
Research projects aimed at proposing fingerprint statistical models based on the likelihood ratio framework have shown that low quality finger impressions left on crime scenes may have significant evidential value. These impressions are currently either not recovered, considered to be of no value when first analyzed by fingerprint examiners, or lead to inconclusive results when compared to control prints. There are growing concerns within the fingerprint community that recovering and examining these low quality impressions will result in a significant increase of the workload of fingerprint units and ultimately of the number of backlogged cases. This study was designed to measure the number of impressions currently not recovered or not considered for examination, and to assess the usefulness of these impressions in terms of the number of additional detections that would result from their examination. 相似文献
903.
Estimating the Impact of Classification Error on the “Statistical Accuracy” of Uniform Crime Reports
James?J.?NolanEmail author Stephen?M.?Haas Jessica?S.?Napier 《Journal of Quantitative Criminology》2011,27(4):497-519
This paper offers a methodological approach for estimating classification error in police records then determining the statistical
accuracy of official crime statistics reported to the Uniform Crime Reporting (UCR) program. Classification error refers to
the mistakes in UCR statistics caused by the misclassification of criminal offenses, for example recording a crime as aggravated
assault when it should have been simple assault. Statistical accuracy refers to the estimated true total of each crime type
based on cancelling effect of undercounting and overcounting crime due to misclassifications. The population for the study
consists of the 12 largest municipal police agencies in a mostly rural southeastern state. Based on a sample of 2,663 records,
the authors illustrate the impact of classification error on the total population of reported offenses. Misclassifications
result in overcounting and undercounting certain crimes. The true number of each crime type, as well as the aggregate Index
Crime, Violent Crime, and Property Crime totals, is estimated based the evaluation of offsetting misclassifications. The findings
show that certain UCR crime categories are greatly undercounted while others are overcounted. The index crime and violent
crime totals are also significantly undercounted; however, when simple assault is added to the index and violent crime categories,
the error in these aggregate numbers is reduced to less than 1%. The results provide a benchmark for assessing the statistical
accuracy of the UCR data. 相似文献
904.
James Midgley 《Political science quarterly》2011,126(2):346-347
905.
Most survey-based research on campaign effects in British elections has focussed on exposure to the campaign. Far less attention has been given to how the campaign is perceived, although American research on the effects of negative campaigning suggests that this is a potentially important area. The article investigates the extent to which vote choices in the 2007 Scottish Parliament election were affected by perceptions of the parties’ campaigns as ‘positive’ or ‘negative’. Partisanship and increased exposure to a party’s campaign increased individuals’ chances of rating a campaign positively. Other things being equal, however, campaigns which come to be seen in a negative light backfire on the party responsible, reducing the propensity of people to vote for it. 相似文献
906.
An emerging forensic service is that of conducting a work product review of a court‐appointed child custody evaluator's evaluation and report. If the reviewer determines there are serious deficiencies in the work product, then the reviewer will provide consultation to the retaining attorney and expert testimony. The reviewer usually is in a hybrid role of consulting/advising the retaining attorney, testifying, and educating the court. Ethical issues in providing forensic services and rebuttal testimony as a reviewer are discussed. Both reviewers and evaluators have a duty to be objective and balanced in their analyses of data and issues. Both types of experts should strive to be helpful to the court and try to serve the best interests of children. Ethical nuances involving review work are discussed. Evaluator and reviewer share the same dataset. Evaluators need to take care to keep a high quality case record with legible interview notes. Reviewers provide a monitoring function for the court or a function of forensic quality control so the court will not be misled by expert testimony of evaluators that is based on flawed data collection and/or analysis. A list of questions is presented for reviewers to use in scrutinizing the quality of the custody evaluation. A list of questions is presented for examining the quality of the reviewer's own work product. The importance of a case analysis and use of conceptual frameworks by evaluators and reviewers is discussed. 相似文献
907.
Linda Fieldstone Debra K. Carter Timothy King James P. McHale 《Family Court Review》2011,49(4):801-817
This report details findings from the nation's first statewide study on parenting coordination. A survey was presented to all known practicing parenting coordinators (PCs) in Florida (N = 207), with 67 (32%) responding. Data concerning PC demographics, how PCs do their work, and how they perceive their clients at different stages of the parenting coordination process suggest substantial similarity between mental health and family law professionals in almost every realm of questioning. Study limitations, implications for further research, and practice considerations are discussed. 相似文献
908.
Satriano J McKinnon K Adoff S 《Journal of prevention & intervention in the community》2007,33(1-2):95-108
People with severe mental illness evidence significantly higher rates of HIV infection than the general population in the United States. Frequently, the only access to health care for this population is through their outpatient mental health care providers. In order to determine how these providers were dealing with the increased risk of HIV infection among this group, a survey of all licensed and certified outpatient mental health care centers in New York State was conducted. The data were compared to a similar previous survey conducted in 1997. 相似文献
909.
910.
This article studies gubernatorial midterm slumps in U.S. state legislative elections. We employ a regression discontinuity design, which allows us to rule out the hypothesis that the midterm slump simply reflects a type of “reversion to the mean” generated by simple partisan swings or the withdrawal of gubernatorial coattails or “anticipatory balancing.” Our results show that the party of the governor experiences an average seat‐share loss of about 3.5 percentage points. We also find evidence suggesting that a large share of the variation in gubernatorial midterm slumps can be accounted for by (1) crude partisan balancing and (2) referendums on state economic performance, with approximately equal weight given to each. 相似文献