全文获取类型
收费全文 | 7357篇 |
免费 | 184篇 |
专业分类
各国政治 | 433篇 |
工人农民 | 324篇 |
世界政治 | 467篇 |
外交国际关系 | 276篇 |
法律 | 4512篇 |
中国政治 | 41篇 |
政治理论 | 1439篇 |
综合类 | 49篇 |
出版年
2020年 | 74篇 |
2019年 | 93篇 |
2018年 | 122篇 |
2017年 | 145篇 |
2016年 | 154篇 |
2015年 | 107篇 |
2014年 | 143篇 |
2013年 | 789篇 |
2012年 | 149篇 |
2011年 | 156篇 |
2010年 | 151篇 |
2009年 | 149篇 |
2008年 | 185篇 |
2007年 | 193篇 |
2006年 | 198篇 |
2005年 | 160篇 |
2004年 | 151篇 |
2003年 | 169篇 |
2002年 | 141篇 |
2001年 | 278篇 |
2000年 | 235篇 |
1999年 | 230篇 |
1998年 | 101篇 |
1997年 | 81篇 |
1996年 | 75篇 |
1995年 | 68篇 |
1994年 | 78篇 |
1993年 | 72篇 |
1992年 | 124篇 |
1991年 | 165篇 |
1990年 | 156篇 |
1989年 | 145篇 |
1988年 | 150篇 |
1987年 | 170篇 |
1986年 | 162篇 |
1985年 | 150篇 |
1984年 | 139篇 |
1983年 | 121篇 |
1982年 | 83篇 |
1981年 | 95篇 |
1980年 | 71篇 |
1979年 | 130篇 |
1978年 | 89篇 |
1977年 | 75篇 |
1976年 | 62篇 |
1975年 | 83篇 |
1974年 | 90篇 |
1973年 | 83篇 |
1972年 | 56篇 |
1971年 | 57篇 |
排序方式: 共有7541条查询结果,搜索用时 15 毫秒
931.
932.
Sandra H. Johnson 《The Journal of law, medicine & ethics》1995,23(3):266-272
933.
934.
A simple and rapid method, for the isolation of eight triazine herbicides from human serum and urine, using Sep-Pak C18 cartridges is presented. After mixing with distilled water, serum and urine samples containing the herbicides, were loaded on Sep-Pak C18 cartridges and eluted with either chloroform only or chloroform/methanol (9:1). The herbicides were detected by capillary gas chromatography with both flame ionization detection (FID) and nitrogen-phosphorus detection (NPD). Separation of eight triazine herbicides from each other and from impurities was generally satisfactory with the use of a non-polar DB-1 capillary column. Recovery of most compounds was excellent for both chloroform and chloroform/methanol (9:1) as elution solvents. Backgrounds were cleaner and evaporation time was shorter for the chloroform only than for the chloroform/methanol (9:1). The NPD gave sensitivity more than 10-20 times higher than that of FID. 相似文献
935.
936.
Prior research on victimization in the United States has generally neglected two key areas—victimization among juveniles and young adults and the connection between offending and victimization. The research presented here fuses these two concerns by examining the effect of delinquent lifestyles on the criminal victimization of teenagers and young adults. An examination of longitudinal data from the first five waves of the National Youth Survey suggests that adolescent involvement in delinquent lifestyles strongly increases the risk of both personal and property victimization. Further, the analysis reveals that a significant proportion of the risk of victimization incurred by different demographic subgroups—especially males—results from greater involvement in lifestyles characterized by delinquency. The authors conclude that victimization patterns among youths cannot be understood apart from criminal and deviant activities. 相似文献
937.
H el Khafief 《The American journal of forensic medicine and pathology》1991,12(3):187-190
Dubai is one of the small countries of the United Arab Emirates located on the shores of the Persian Gulf in the Middle East. This report deals with two deaths: one an unusual method of suicide by hanging and the other, a death under investigation into whether it was accidental or suicidal. 相似文献
938.
939.
The unlabeled antibody (PAP) immunoperoxidase technique was applied to the ABO blood grouping of human scalp hairs. Hair samples were subjected to longitudinal- or cross-sectioning, thus obtaining suitable samples for subsequent immunostaining. The immunostaining was carried out using rabbit anti-A and anti-B sera as the primary antibodies. With this technique, the group-specific staining which is revealed as a dark brown precipitate was clearly observed within the medullae of the hair shaft, and depending on the presence or absence of these precipitates, respective blood groups of unknown hair samples were determined. At the hair root, on the other hand, positive stainings were observed not only in medullary cells but also in some cortical cells of the keratogenous zone. From the present study, it can be safely said that this technique is of practical use for the ABO blood grouping from a minute (less than 3 mm) hair sample. 相似文献
940.
A case is presented where phentermine, a sympathomimetic amine used as an anorectic drug, is believed to have significantly contributed to the death of an individual in whom other drugs were also found. Blood, urine, and tissue concentrations of phentermine are reported and compared to other cases in the literature. 相似文献