全文获取类型
收费全文 | 6983篇 |
免费 | 195篇 |
专业分类
各国政治 | 324篇 |
工人农民 | 295篇 |
世界政治 | 564篇 |
外交国际关系 | 284篇 |
法律 | 4204篇 |
中国政治 | 57篇 |
政治理论 | 1421篇 |
综合类 | 29篇 |
出版年
2021年 | 52篇 |
2020年 | 88篇 |
2019年 | 136篇 |
2018年 | 178篇 |
2017年 | 171篇 |
2016年 | 169篇 |
2015年 | 109篇 |
2014年 | 159篇 |
2013年 | 781篇 |
2012年 | 181篇 |
2011年 | 194篇 |
2010年 | 155篇 |
2009年 | 183篇 |
2008年 | 219篇 |
2007年 | 213篇 |
2006年 | 207篇 |
2005年 | 170篇 |
2004年 | 186篇 |
2003年 | 168篇 |
2002年 | 129篇 |
2001年 | 334篇 |
2000年 | 304篇 |
1999年 | 211篇 |
1998年 | 94篇 |
1997年 | 96篇 |
1996年 | 64篇 |
1995年 | 59篇 |
1994年 | 58篇 |
1993年 | 47篇 |
1992年 | 136篇 |
1991年 | 152篇 |
1990年 | 148篇 |
1989年 | 137篇 |
1988年 | 120篇 |
1987年 | 134篇 |
1986年 | 113篇 |
1985年 | 113篇 |
1984年 | 103篇 |
1983年 | 93篇 |
1982年 | 68篇 |
1981年 | 80篇 |
1980年 | 46篇 |
1979年 | 80篇 |
1978年 | 45篇 |
1975年 | 38篇 |
1974年 | 57篇 |
1973年 | 58篇 |
1972年 | 41篇 |
1971年 | 37篇 |
1970年 | 32篇 |
排序方式: 共有7178条查询结果,搜索用时 15 毫秒
881.
Four kinds of DNA probes that recognize hypervariable regions (HVR) were studied for parentage testing and individual identification. Allele frequencies and their confidence intervals among unrelated Japanese individuals were obtained. Codominant segregation of the polymorphism was confirmed in family studies. Two a priori probabilities were calculated for each HVR locus: the exclusion probabilities for an alleged father/mother/child trio and for an alleged parent/child duo, and the probabilities of matching of genotypes of two unrelated individuals or two siblings. The ease of availability of the probes and their highly discriminating polymorphic patterns mean they could be very useful for forensic purposes. 相似文献
882.
K J O'Connell H A Frazier M A Clark P J Christenson B T Keyes A Josselson 《Journal of forensic sciences》1988,33(2):410-417
An animal model was designed to evaluate the ability of the standard military flak jacket to protect the kidneys from direct ballistic trauma. Yorkshire swine were anesthetized and their flanks were protected by flak jackets. Ballistic insults ranging from a low-velocity handgun to a high-velocity rifle were evaluated. The results demonstrate that a flak jacket provides adequate protection against low- and mid-velocity projectiles since none of the animals from this group had evidence of internal trauma and because only minor superficial surgical attention would have been required. Survivability in each case was considered to be excellent. The flak jacket failed to provide any protection against several types of high-velocity bullets. These weapons caused severe internal injury to the genitourinary system as well as to other major organ systems. Survival would have been unlikely. 相似文献
883.
884.
An infant fatality following accidental ingestion of ajmaline is described. Ajmaline was determined by thin-layer chromatography and infrared spectrophotometry, and quantitated by high performance liquid chromatography. The ajmaline concentration in blood was 5.5 micrograms/mL. The toxicological data relevant to the interpretation of case findings are presented. 相似文献
885.
886.
887.
888.
889.
890.
This Article proposes a procedure for making decisions to forego life-sustaining treatment for adult, developmentally disabled, public wards who are not competent to make health care decisions. Few commentators or cases address the special considerations involved in making life-sustaining treatment decisions for this patient population. The proposal attempts to fill this gap with a patient-centered process that allows decisionmakers, without prior judicial approval, to forego life-sustaining treatment for adult, developmentally disabled, public wards who have been reliably diagnosed with specific medical conditions. 相似文献