全文获取类型
收费全文 | 2214篇 |
免费 | 58篇 |
专业分类
各国政治 | 35篇 |
工人农民 | 33篇 |
世界政治 | 27篇 |
外交国际关系 | 58篇 |
法律 | 873篇 |
中国共产党 | 36篇 |
中国政治 | 167篇 |
政治理论 | 74篇 |
综合类 | 969篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 47篇 |
2021年 | 54篇 |
2020年 | 52篇 |
2019年 | 30篇 |
2018年 | 22篇 |
2017年 | 33篇 |
2016年 | 25篇 |
2015年 | 22篇 |
2014年 | 105篇 |
2013年 | 178篇 |
2012年 | 105篇 |
2011年 | 143篇 |
2010年 | 115篇 |
2009年 | 151篇 |
2008年 | 154篇 |
2007年 | 185篇 |
2006年 | 210篇 |
2005年 | 120篇 |
2004年 | 124篇 |
2003年 | 135篇 |
2002年 | 88篇 |
2001年 | 77篇 |
2000年 | 34篇 |
1999年 | 16篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
排序方式: 共有2272条查询结果,搜索用时 15 毫秒
251.
252.
253.
254.
POPULATION: Population: Illinois Caucasian ( n =117), Illinois African American ( n =218), and Illinois Hispanic ( n =68). 相似文献
255.
256.
257.
258.
Rib histological age estimation requires the evaluation of the middle third of the sixth rib. Human ribs have thin cortices and, when recovered, are often fragmented or absent, making it difficult to identify a specific midthoracic rib. This research explores the amount of microstructure variation in the middle third of the midthoracic ribs and determines whether the sixth rib age prediction equation can be applied to non-sixth ribs with similar accuracy. The amount of variability must be evaluated in order to meet the criterion for evidentiary examination. The sample consists of 120 cortical bone cross-sections from the middle third of ribs 3-8 removed from 20 cadavers. For each rib, osteon population densities (OPDs) and associated age estimates were calculated. The results demonstrate that non-sixth ribs can provide similar OPD values compared with those of the sixth ribs; however, individual variation proved to be significantly associated with bias, suggesting that individual factors influence the magnitude and direction of bias in non-sixth rib OPD values. This demonstrates the importance of evaluating multiple cross-sections (both intra- and inter-rib) to estimate age due to the normal remodeling variation within individuals. 相似文献
259.
Victimization incidence rates produced from the National Crime Victimization Survey (NCVS) are a generally accepted annual
indicator of the amount and type of crime in the United States. However, persons who report a large number of similar victimizations—known
as series victimizations in the NCVS—are currently excluded in government reports of annual violent victimizations. This paper
quantifies the effect of series incident counting procedures on national estimates of violent victimization. The findings
suggest that these high-volume repeat victims can have a significant impact on the magnitude and distribution of violent victimization.
Current government counting rules that exclude series incidents do not include about three out of every five violent victimizations
and distorts the characterization and risk of violence in the United States. However, the inclusion of series incidents introduces
significant estimate instability. One remedy is to use prevalence rates in concert with incidence rates to present a more
complete and reliable picture of victimization.
相似文献
Michael PlantyEmail: |
260.
We describe two short amplicon autosomal short tandem repeat (miniSTR) quadruplex systems for eight loci D1S1171, D2S1242, D3S1545, D4S2366, D12S391, D16S3253, D20S161, and D21S1437, unlinked from the combined DNA index system (non-CODIS) loci, using newly designed primer sets. The results of an assay of 411 Japanese individuals showed that polymerase chain reaction (PCR) products within the eight loci were less than 150bp in size, without the seven additional bases for adenylation. The frequency distributions in the loci showed no deviations from Hardy-Weinberg equilibrium expectations. The accumulated power of discrimination and power of exclusion for the eight loci were 0.9999999991 and 0.998, respectively. For assay of highly degraded DNA, including artificially degraded samples and the degraded forensic casework samples assessed with the present miniSTR quadruplex systems, the systems proved quite effective in analyzing degraded DNA. 相似文献