全文获取类型
收费全文 | 78601篇 |
免费 | 3090篇 |
专业分类
各国政治 | 4682篇 |
工人农民 | 3138篇 |
世界政治 | 6836篇 |
外交国际关系 | 4052篇 |
法律 | 39470篇 |
中国共产党 | 11篇 |
中国政治 | 780篇 |
政治理论 | 21759篇 |
综合类 | 963篇 |
出版年
2021年 | 457篇 |
2020年 | 1223篇 |
2019年 | 1582篇 |
2018年 | 1826篇 |
2017年 | 2154篇 |
2016年 | 2337篇 |
2015年 | 1900篇 |
2014年 | 2187篇 |
2013年 | 10938篇 |
2012年 | 1909篇 |
2011年 | 2055篇 |
2010年 | 2001篇 |
2009年 | 2181篇 |
2008年 | 2046篇 |
2007年 | 2043篇 |
2006年 | 2125篇 |
2005年 | 2029篇 |
2004年 | 1944篇 |
2003年 | 1778篇 |
2002年 | 1781篇 |
2001年 | 2217篇 |
2000年 | 1934篇 |
1999年 | 1656篇 |
1998年 | 1267篇 |
1997年 | 1094篇 |
1996年 | 1051篇 |
1995年 | 1017篇 |
1994年 | 1073篇 |
1993年 | 1070篇 |
1992年 | 1214篇 |
1991年 | 1247篇 |
1990年 | 1162篇 |
1989年 | 1256篇 |
1988年 | 1204篇 |
1987年 | 1221篇 |
1986年 | 1215篇 |
1985年 | 1257篇 |
1984年 | 1088篇 |
1983年 | 1149篇 |
1982年 | 986篇 |
1981年 | 943篇 |
1980年 | 752篇 |
1979年 | 839篇 |
1978年 | 672篇 |
1977年 | 596篇 |
1976年 | 555篇 |
1975年 | 483篇 |
1974年 | 494篇 |
1973年 | 491篇 |
1972年 | 433篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
K. Minakata O. Suzuki Y. Ishikawa H. Seno M. Asano 《Forensic Science International Supplement Series》1991,50(2)
A simple and sensitive method is described for quantitative analysis of chlorpromazine in blood, serum, urine and tissue homogenate. The chlorpromazine cation radical produced by adding perchloric acid and 2,3-dichloro-5,6-dicyano-p-benzoquinone to the sample can be detected by the ESR method at room temperature. The sensitivity limit is 10 ng, that is, 20 μl of the solution containing 0.5 μg chlorpromazine/ml. The time needed for the measurement is within 10 min. The chlorpromazine radical thus produced is very stable; for example, 95% of the radical was observed after 24 h. The advantage of this method is discussed by comparing with the ordinary spectrophotometry which requires the purification of the sample. 相似文献
212.
213.
Although there has been speculation regarding the pervasiveness and nature of judicial decisions regarding life-sustaining medical treatment (LSMT), no attempt has been made to empirically assess their prevalence or the issues they address. An exploratory study utilizing a mail survey of a nationwide random sample (N = 905) of state trial court judges was conducted to provide initial information regarding this decision-making process. Twenty-two percent of the responding judges had heard at least one LSMT case, and judicial review did not appear endemic to particular states. The number of judges hearing LSMT cases dropped from 1975 to 1981 but has increased since then. Three major issues predominate: patient competency, appointment of a surrogate decisionmaker, and resolution of the ultimate issue of forgoing LSMT. Relatively few cases either contested a prior directive's validity or involved imposing sanctions for instituting or forgoing LSMT. Although subject to different interpretations, the results suggest the courts are having a significant impact on certain aspects of the LSMT decision-making process. However, the infrequency with which any one judge is called upon to make an LSMT decision causes concern about the judiciary's ability to respond in a timely and appropriate manner. With their potential for a profound effect on the actions of health care providers, greater attention to this decision-making process is warranted. 相似文献
214.
215.
216.
217.
The remains of an unidentified female neonate were discovered in a field in central Missouri. Examination revealed bilateral absence of the parietal bones. A search of the literature describing similar defects suggests that the present case represents a unique condition, described here for the first time. 相似文献
218.
219.
220.