全文获取类型
收费全文 | 29674篇 |
免费 | 1542篇 |
国内免费 | 5篇 |
专业分类
各国政治 | 1170篇 |
工人农民 | 1455篇 |
世界政治 | 1961篇 |
外交国际关系 | 944篇 |
法律 | 19835篇 |
中国共产党 | 7篇 |
中国政治 | 241篇 |
政治理论 | 5363篇 |
综合类 | 245篇 |
出版年
2020年 | 514篇 |
2019年 | 569篇 |
2018年 | 1002篇 |
2017年 | 1128篇 |
2016年 | 1056篇 |
2015年 | 670篇 |
2014年 | 688篇 |
2013年 | 2672篇 |
2012年 | 761篇 |
2011年 | 1083篇 |
2010年 | 1171篇 |
2009年 | 1039篇 |
2008年 | 980篇 |
2007年 | 974篇 |
2006年 | 823篇 |
2005年 | 708篇 |
2004年 | 702篇 |
2003年 | 713篇 |
2002年 | 615篇 |
2001年 | 1037篇 |
2000年 | 831篇 |
1999年 | 738篇 |
1998年 | 385篇 |
1997年 | 300篇 |
1996年 | 311篇 |
1995年 | 315篇 |
1994年 | 342篇 |
1993年 | 309篇 |
1992年 | 520篇 |
1991年 | 565篇 |
1990年 | 538篇 |
1989年 | 506篇 |
1988年 | 510篇 |
1987年 | 440篇 |
1986年 | 519篇 |
1985年 | 486篇 |
1984年 | 434篇 |
1983年 | 400篇 |
1982年 | 321篇 |
1981年 | 322篇 |
1980年 | 250篇 |
1979年 | 325篇 |
1978年 | 233篇 |
1977年 | 194篇 |
1976年 | 161篇 |
1975年 | 198篇 |
1974年 | 198篇 |
1973年 | 167篇 |
1972年 | 153篇 |
1971年 | 159篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
Presented in this paper are the initial results involving the use of the nose or outer ear as temperature measurement sites to determine the postmortem period of the human corpse. Simple mathematical models for both sites are developed based on cooling curves of five corpses. Analysis of errors between actual and calculated postmortem intervals suggest that in its present form, the described methods would not be suitable for use in accurately determining the time since death of human corpses. 相似文献
172.
173.
D Callahan 《American journal of law & medicine》1992,18(1-2):1-13
Proposals to ration health care in the United States meet a number of objections, symbolic and literal. Nonetheless, an acceptance of the idea of rationing is a necessary first step toward universal health insurance. It must be understood that universal health care requires an acceptance of rationing, and that such an acceptance must precede enactment of a program, if it is to be economically sound and politically feasible. Commentators have argued that reform of the health care system should come before any effort to ration. On the contrary, rationing and reform cannot be separated. The former is the key to the latter, just as rationing is the key to universal health insurance. 相似文献
174.
175.
176.
177.
Incarceration rates in the United States dramatically increased over the past several decades. This trend has drawn significant academic attention to prison overcrowding and its potential effect on inmate misconduct. The empirical relationship between inmate misconduct and overcrowding, however, is less than clear. To be sure, studies indicating positive, negative, and null relationships can all be found in the literature. The current research subjects this body of literature to a meta-analysis in an effort to: (1) clarify the direction and strength of the relationship between overcrowding and rates of prison misconduct across all studies, and (2) to uncover the degree to which variation in research outcomes can be attributed to methodological differences across studies. Results indicate that prison crowding has little substantive impact on inmate misconduct. Implications of the findings are discussed in detail. 相似文献
178.
179.
Sar A. Levitan 《政策研究评论》1987,6(4):712-721
Those in need of employment and training programs face a variety of difficulties. Accordingly, the federal response to labor market problems has encompassed a wide range of initiatives. These include preparing people for work (through skills training, the Job Corps, work experience programs); improving the functioning of the labor market (through matching workers with jobs, establishing a minimum wage, and the Targeted Jobs Tax Credit program); and preventing discrimination. Unresolved issues in these areas are examined. They include who should be targeted for federal assistance, which levels of government can best operate programs, how public versus private efforts should be balanced, how limited resources should be distributed, and how the welfare versus work question should be resolved. 相似文献
180.
Observations of high velocity bloodspatter on adjacent objects 总被引:1,自引:0,他引:1
In a recent homicide investigation, high velocity backspatter was observed on the sleeve cuff of the accused. These minute droplets were discovered only after microscopic examination and were limited in number. A study was initiated to determine if these were truly backspatter droplets or transferred blood produced from light contact with a bloody item. It was observed that the backspattered blood was primarily limited to contact or near contact shots. An exception was a shot into an already bloody surface. It was found that backspattered blood would deposit on the shooter's shirt sleeve irrespective of the weave pattern. Transferred blood was observed only on the fiber tops. This information was found to be useful in reconstruction of events in suicides as well as possible homicides. 相似文献