全文获取类型
收费全文 | 69137篇 |
免费 | 3283篇 |
专业分类
各国政治 | 4483篇 |
工人农民 | 2893篇 |
世界政治 | 5978篇 |
外交国际关系 | 3806篇 |
法律 | 32895篇 |
中国共产党 | 9篇 |
中国政治 | 748篇 |
政治理论 | 20670篇 |
综合类 | 938篇 |
出版年
2021年 | 407篇 |
2020年 | 1160篇 |
2019年 | 1515篇 |
2018年 | 1663篇 |
2017年 | 1955篇 |
2016年 | 2177篇 |
2015年 | 1829篇 |
2014年 | 2099篇 |
2013年 | 10530篇 |
2012年 | 1609篇 |
2011年 | 1727篇 |
2010年 | 1822篇 |
2009年 | 2074篇 |
2008年 | 1759篇 |
2007年 | 1729篇 |
2006年 | 1881篇 |
2005年 | 1760篇 |
2004年 | 1666篇 |
2003年 | 1489篇 |
2002年 | 1513篇 |
2001年 | 1640篇 |
2000年 | 1410篇 |
1999年 | 1293篇 |
1998年 | 1110篇 |
1997年 | 975篇 |
1996年 | 959篇 |
1995年 | 915篇 |
1994年 | 925篇 |
1993年 | 942篇 |
1992年 | 996篇 |
1991年 | 1032篇 |
1990年 | 1005篇 |
1989年 | 1034篇 |
1988年 | 1043篇 |
1987年 | 1053篇 |
1986年 | 1005篇 |
1985年 | 1078篇 |
1984年 | 947篇 |
1983年 | 974篇 |
1982年 | 900篇 |
1981年 | 845篇 |
1980年 | 663篇 |
1979年 | 723篇 |
1978年 | 607篇 |
1977年 | 533篇 |
1976年 | 489篇 |
1975年 | 425篇 |
1974年 | 448篇 |
1973年 | 451篇 |
1972年 | 372篇 |
排序方式: 共有10000条查询结果,搜索用时 208 毫秒
241.
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
242.
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
243.
244.
顶空固相微萃取气相色谱法快速检测尿液中氯胺酮 总被引:1,自引:1,他引:0
目的建立快速检测吸毒人员尿液中氯胺酮的顶空固相微萃取(HS/SPME)-GC/NPD的方法。方法样品瓶中加入尿液、氢氧化钠溶液、氯化钠,在95℃下加热搅拌,用聚二甲基硅氧烷SPME萃取头(100μm)顶空萃取20min,气相色谱氮磷检测器检测,外标法定量。结果尿液中氯胺酮浓度在0.2~20.0μg/ml范围内呈现线性关系(r2=0.9965),尿液添加1.0μg氯胺酮,平均回收率102.6%,RSD=3.39%(n=7),检测限1.13ng/ml(S/N=3)。结论建立的方法简单、快速、灵敏、准确,十分适合尿液等生物检材中氯胺酮的快速定性定量分析。 相似文献
245.
246.
247.
248.
DAVID P. FARRINGTON 《犯罪学》2003,41(2):221-225
The main aim of this paper is to advance knowledge and (especially) theories about developmental and life‐course criminology (DLC). First, I review the widely accepted DLC findings that all DLC theories have been designed to explain. Second, I review more contentious and unresolved empirical DLC issues that might present challenges to DLC theories. Third, I describe my own DLC theory and specify how it addresses key empirical and theoretical questions. Fourth, I summarize five important DLC theories, by Catalano and Hawkins, Sampson and Laub, Moffitt, LeBlanc, and Thornberry and Krohn. Fifth, I identify differences in assumptions and predictions between my theory and the other five theories. Finally, I recommend a detailed comparison of the key features of all DLC theories, of their answers to key empirical and theoretical questions, and of their predictions regarding key unresolved empirical DLC issues. 相似文献
249.
Research has indicated that school factors such as communal school organization and student bonding are predictive of school disorder, with greater communal organization and greater student bonding leading to less delinquency and victimization. Data from a nationally representative sample of 254 public, nonalternative, secondary schools were used to examine structural equation models representing hypothesized relationships among communal school organization, student bonding, and school disorder. The hypothesis that communally organized schools would have less disorder held true for teacher victimization and student delinquency, but not for student victimization. In addition, the hypothesis that the relationship between communal school organization and school disorder would be mediated by student bonding was supported for student delinquency, but not for teacher victimization. 相似文献
250.
Ernest L. Nickels 《Journal of criminal justice》2007,35(5):570
“Discretion” holds an unrivaled position at the core of the notional inventory employed in the study of criminal justice generally and policing particularly. Efforts to systematically define the term have been irregular and its status in the empirical literature is an ambiguous one. While spoken of as a quantitative aspect of the policing which influences behavior, measurement is rarely addressed. After sketching problems in present formulations, discretion is recast in terms of perceived job autonomy and an outline of two general constructs is contributed in hopes of renewing consideration of the potential relevance of the concept for police theory and research. 相似文献