全文获取类型
收费全文 | 10594篇 |
免费 | 292篇 |
专业分类
各国政治 | 400篇 |
工人农民 | 379篇 |
世界政治 | 718篇 |
外交国际关系 | 286篇 |
法律 | 6721篇 |
中国政治 | 67篇 |
政治理论 | 2227篇 |
综合类 | 88篇 |
出版年
2020年 | 102篇 |
2019年 | 155篇 |
2018年 | 190篇 |
2017年 | 218篇 |
2016年 | 212篇 |
2015年 | 162篇 |
2014年 | 182篇 |
2013年 | 945篇 |
2012年 | 217篇 |
2011年 | 264篇 |
2010年 | 211篇 |
2009年 | 268篇 |
2008年 | 270篇 |
2007年 | 271篇 |
2006年 | 265篇 |
2005年 | 243篇 |
2004年 | 234篇 |
2003年 | 243篇 |
2002年 | 235篇 |
2001年 | 423篇 |
2000年 | 366篇 |
1999年 | 294篇 |
1998年 | 158篇 |
1997年 | 125篇 |
1996年 | 136篇 |
1995年 | 132篇 |
1994年 | 135篇 |
1993年 | 134篇 |
1992年 | 233篇 |
1991年 | 251篇 |
1990年 | 240篇 |
1989年 | 250篇 |
1988年 | 225篇 |
1987年 | 223篇 |
1986年 | 263篇 |
1985年 | 256篇 |
1984年 | 229篇 |
1983年 | 214篇 |
1982年 | 151篇 |
1981年 | 127篇 |
1980年 | 115篇 |
1979年 | 151篇 |
1978年 | 85篇 |
1977年 | 111篇 |
1976年 | 95篇 |
1975年 | 71篇 |
1974年 | 90篇 |
1973年 | 84篇 |
1972年 | 78篇 |
1971年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
932.
J L McClain F B Jordan R Blakeney 《The American journal of forensic medicine and pathology》1986,7(2):172-173
Human cannibal cases are relatively rare in modern civilized societies. We report a single case of familial cannibalism that occurred in Oklahoma in 1977. The investigation posed unique problems in pathology, psychiatry, criminalistics, and serology. 相似文献
933.
934.
Lyophilized Sigma Type III trypsin has been applied to latent prints two weeks to two months old. This trypsin preparation eliminates the background problems that had been encountered with old prints in a previous study. Zinc chloride treatment of latent prints previously exposed to ninhydrin enhances their detectability upon laser examination. However, it has been reported that the zinc chloride reaction occasionally fails to occur. Accordingly, we have investigated the optimization of this reaction. We find that high humidity and elevated temperature, particularly the former, are needed. Cadmium nitrate, although it produces weaker fluorescence than zinc chloride, may at times be useful. Reaction conditions are much the same as those for zinc chloride. 相似文献
935.
936.
937.
Previous studies have established that repeat victimizations occur more frequently than would be expected if households within a particular area were victimized randomly. This implies that characteristics of the household affect the victimization rate. Even controlling for these characteristics, we find that a Poisson model does not capture the distribution of victimizations because repeat victimizations are more concentrated than it would indicate. This leads us to adopt the negative binomial generalization of the Poisson model. Our analysis uses sociodemographic attributes of the household and community-level characteristics to predict victimizations, with the victimization data being the observed number of property crime victimizations from the 1992 British Crime Survey. The negative binomial generalization is found to be highly statistically significant and the crime concentration it implies becomes much more marked as the predicted number of victimizations increases. 相似文献
938.
External beam proton-induced X-ray emission (PIXE) analysis has been used to verify the presence of lead in the finger bone of a murder victim. The deceased, who had been buried several years, was known to have suffered a bullet wound to his right hand several years before death. X-ray radiographs of the right second proximal phalanx revealed the possible presence of metal fragments below the surface of the bone. To verify the presence of lead in a nondestructive manner, the bone was scanned with a 1.5-MeV proton beam. PIXE analysis showed that lead was present only in the vicinity of the fragments previously detected in the radiographs. A study of gunshot residue in bone shows that the distribution of lead around the bullet hole is independent of the firing distance for distances greater than 0.6 m. 相似文献
939.
940.
Nuclear spin tomography since its beginnings in the seventies has steadily gained in importance as a method of examination in medical diagnostics as it produces a picture. In the field of forensic medicine the NMR technique as used for anatomic-anthropologic issues attempting to identify skulls this is a valuable supplement to an extension of the existing methods of investigation. The results of a measurement of the thickness of soft facial tissue in a live test person is shown as compared to measures obtained by sonography. 相似文献