全文获取类型
收费全文 | 1122篇 |
免费 | 39篇 |
专业分类
各国政治 | 40篇 |
工人农民 | 61篇 |
世界政治 | 80篇 |
外交国际关系 | 53篇 |
法律 | 558篇 |
中国政治 | 15篇 |
政治理论 | 334篇 |
综合类 | 20篇 |
出版年
2023年 | 7篇 |
2022年 | 8篇 |
2020年 | 21篇 |
2019年 | 15篇 |
2018年 | 23篇 |
2017年 | 30篇 |
2016年 | 31篇 |
2015年 | 24篇 |
2014年 | 21篇 |
2013年 | 160篇 |
2012年 | 35篇 |
2011年 | 42篇 |
2010年 | 36篇 |
2009年 | 36篇 |
2008年 | 54篇 |
2007年 | 31篇 |
2006年 | 41篇 |
2005年 | 33篇 |
2004年 | 27篇 |
2003年 | 29篇 |
2002年 | 29篇 |
2001年 | 22篇 |
2000年 | 28篇 |
1999年 | 17篇 |
1998年 | 24篇 |
1997年 | 18篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 18篇 |
1992年 | 21篇 |
1991年 | 13篇 |
1990年 | 19篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 12篇 |
1986年 | 17篇 |
1985年 | 19篇 |
1984年 | 15篇 |
1983年 | 9篇 |
1982年 | 18篇 |
1981年 | 13篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1973年 | 7篇 |
1972年 | 6篇 |
1971年 | 6篇 |
排序方式: 共有1161条查询结果,搜索用时 31 毫秒
71.
72.
A DNA microarray system for forensic SNP analysis 总被引:3,自引:0,他引:3
Forensic DNA analysis is routinely performed using polymorphic short tandem repeat (STR) markers. However, for degraded or minute DNA samples, analysis of autosomal single nucleotide polymorphisms (SNPs) in short fragments might be more successful. Furthermore, sequencing of mitochondrial DNA (mtDNA) is often performed on highly degraded or scarce samples due to the high copy number of mtDNA in each cell. Due to the increasing number of complete mtDNA genome sequences available, the limited discrimination power of an mtDNA analysis, may be increased by analysis of coding region polymorphisms in addition to the non-coding variation. Since sequence analysis of the coding region would require more material than generally present in forensic samples, an alternative SNP analysis approach is required. We have developed a one-colour microarray-based SNP detection system for limited forensic materials. The method is based on minisequencing in solution prior to hybridisation to universal tag-arrays. In a first outline of a forensic chip, a combination of 12 nuclear and 21 mitochondrial SNP markers are analysed simultaneously. The mitochondrial markers on the chip are polymorphisms within the hypervariable region as well as in the coding region. Even though the number of markers in the current system is limited, it can easily be extended to yield a greater power of discrimination. When fully developed, microarray analysis provides a promising system for efficient sensitive SNP analysis of forensic samples in the future. 相似文献
73.
74.
75.
Interpretation of postmortem change in cadavers in Spain 总被引:2,自引:0,他引:2
Estimating time since death is especially difficult in the examination of poorly preserved cadavers and depends on the experience of the examiner and comparison with previously documented cases showing similar characteristics. The present study reports on information obtained over the past ten years through the work of the Laboratorio de Antropología y Odontología Forense (LAF) of the Instituto Anatómico Forense de Madrid, Spain, in particular evaluating how the type of fracture influences postmortem change. From the original 225 forensic cases examined between 1992 and 2002 in the LAF, a sample of 29 cases were selected from various regions of the Spanish mainland. A data collection protocol was established to reflect factors which the existing specialized literature, documenting the relation existing in the sample analyzed between time since death and the extent of postmortem change, which in the environments examined are distributed into the following phases: Phase 1 (putrefaction): one week to one month on the surface and two months in water. Phase 2 (initial skeletonization): two months on the surface and five to six months in water. Phase 3 (advanced skeltonization): six months to 1.5 years on the surface and 2.5 years buried. Phase 4 (complete skeletonization): about one year on the surface and three years buried. This paper also provide useful information on the impact of carrion insect activity, location, climate, seasonality, and predator. 相似文献
76.
Armstrong A Babrauskas V Holmes DL Martin C Powell R Riggs S Young LD 《Journal of forensic sciences》2004,49(4):741-748
Tests have determined that boots or shoes of individuals at a fire scene do not transport sufficient contaminants ("tracking") through the fire scene to produce a positive laboratory result for the presence of gasoline in a fire scene that was not present at the time of the fire. Questions about the validity of forensic laboratory results have been raised on the basis that low-level gasoline residues detected in the laboratory samples could have been the result of transporting the residue by footwear contaminated from the fire scene ("tracking"). The data collected in this study establish that "tracking" does not lead to false-positive laboratory results. Canines trained and experienced in the detection of trace ignitable liquid residues were also utilized in this study. The canine results confirmed that properly trained canines show a higher sensitivity than do standard ASTM laboratory techniques for fire debris analysis. In a few cases, canines responded to contamination, but laboratory testing (which is the definitive indicator) did not produce positive results. 相似文献
77.
Some previous research indicates that confidence affects the accuracy of probabilistic clinical ratings of risk for violence among civil psychiatric inpatients. The current study investigated the impact of confidence on actuarial and structured professional risk assessments, in a forensic psychiatric population, using community violence as the outcome criteria. Raters completed the HCR-20 violence risk assessment scheme for a sample of 100 forensic psychiatric patients. Results showed that accuracy of both actuarial judgments (HCR-20 total scores) and structured professional judgments (of low, moderate, and high risk) were substantially more accurate when raters were more confident about their judgments. Findings suggest that confidence of ratings should be studied as a potentially important mediator of structured professional and actuarial risk judgments. 相似文献
78.
79.
Journal of Youth and Adolescence - 相似文献
80.
H Brown D M Cauchi J L Holden F C Allen S Cordner P Thatcher 《Forensic science international》1999,100(3):179-186
A statistical investigation of the relationship between firing range and the amount and distribution of gunshot residue (GSR), used automated image analysis (IA) to quantify GSR deposit resulting from firings into pig skin, from distances ranging between contact and 45 cm. Overall, for a Ruger .22 semi-automatic rifle using CCI solid point, high velocity ammunition, the total area of GSR deposit on the skin sections decreased in a non-linear fashion with firing range. More specifically there were significant differences in the amount of GSR deposited from shots fired at contact compared with shots fired from distances between 2.5 and 45 cm; and between shots fired from a distance of 20 cm or less, with shots fired at a distance of 30 cm or more. In addition, GSR particles were heavily concentrated in the wound tract only for contact and close range shots at 2.5 cm, while the particle distribution was more uniform between the wound tract and the skin surfaces for shots fired from distances greater than 2.5 cm. Consequently, for future scientific investigations of gunshot fatalities, once standards have been established for the weapon and ammunition type in question, image analysis quantification of GSR deposited in and around the gunshot wound may be capable of providing a reliable, statistical basis for estimating firing range. 相似文献