全文获取类型
收费全文 | 12551篇 |
免费 | 323篇 |
专业分类
各国政治 | 451篇 |
工人农民 | 611篇 |
世界政治 | 756篇 |
外交国际关系 | 332篇 |
法律 | 8086篇 |
中国政治 | 91篇 |
政治理论 | 2452篇 |
综合类 | 95篇 |
出版年
2020年 | 120篇 |
2019年 | 175篇 |
2018年 | 306篇 |
2017年 | 260篇 |
2016年 | 333篇 |
2015年 | 212篇 |
2014年 | 211篇 |
2013年 | 1026篇 |
2012年 | 358篇 |
2011年 | 380篇 |
2010年 | 241篇 |
2009年 | 317篇 |
2008年 | 309篇 |
2007年 | 316篇 |
2006年 | 308篇 |
2005年 | 632篇 |
2004年 | 347篇 |
2003年 | 283篇 |
2002年 | 264篇 |
2001年 | 447篇 |
2000年 | 373篇 |
1999年 | 307篇 |
1998年 | 165篇 |
1997年 | 128篇 |
1996年 | 145篇 |
1995年 | 138篇 |
1994年 | 138篇 |
1993年 | 136篇 |
1992年 | 259篇 |
1991年 | 274篇 |
1990年 | 270篇 |
1989年 | 281篇 |
1988年 | 255篇 |
1987年 | 248篇 |
1986年 | 288篇 |
1985年 | 277篇 |
1984年 | 237篇 |
1983年 | 229篇 |
1982年 | 153篇 |
1981年 | 130篇 |
1980年 | 118篇 |
1979年 | 161篇 |
1978年 | 94篇 |
1977年 | 115篇 |
1976年 | 96篇 |
1975年 | 82篇 |
1974年 | 112篇 |
1973年 | 93篇 |
1972年 | 92篇 |
1971年 | 85篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Using merged administrative data from welfare reform evaluations in three states, we estimate the effects of child care subsidy use on the length of time it takes for a welfare applicant to move into substantial employment. Findings show that the use of a child care subsidy during an unemployed or marginally employed spell of welfare receipt is associated with between a 0.6 and 1.7 quarter (or 11% to 34%) reduction in the time to substantial employment in two of the three state samples. The positive influence of subsidy use on transitions to substantial employment is strongest for those welfare applicants with the lowest earnings who are mixing welfare and work prior to subsidy receipt. 相似文献
102.
Law and Philosophy - 相似文献
103.
104.
105.
Quadratic pieces of fleece measuring 16 mm2 were soaked with 10 different blood-samples in the dilution steps of 1:1, 1:10, 1:100, 1:1000, respectively, and were tested in blood group typing and identification tests of forensic serology. The above spezified dilutions correspond with 5 microliters, 0.5 microliter, 0.05 microliter and 0.005 microliter of blood, respectively. The detection limit of the microspectrometric test for blood was the dilution 1:10, of the porphyrine test a dilution above 1:100, whereas the preliminary test for blood (peroxidase) succeeded always up to a dilution of 1:1000 and the species determination by the radial immunodiffusion test in agar gels succeeded in most cases op to a dilution of 1:1000. The detection limit of the anti-human globulin inhibition test was between the dilution steps 1:10 and 1:100 when non-titrated and undiluted anti-human globulin serum was used. Gc- and ABO-grouping were possible up to a dilution of 1:100 and were thus the most sensitive grouping systems. Phenotyping of the enzyme-systems and the Gm/Km-system usually required stains with considerably higher blood concentrations i.e. stains of undiluted blood. 相似文献
106.
107.
Sarmistha R. Majumdar 《政策研究评论》2005,22(2):157-169
In 1990, the state of California passed the pioneering mandate on zero emission vehicles (ZEV). This technology‐forcing regulation is aimed at improvement of air quality and protection of public health from the adverse effects of air pollutants from automobiles. Facing severe opposition from the auto industry, the mandate has been revised a number of times, most recently in 2003, whereby the requirement for ZEVs have been made to align with the pace of technology development. Review of strategies used in implementation of the mandate has revealed greater emphasis on the economic incentives for rather than on environmental merits of ZEVs. Using prospect theory as the framework for analysis, the reasons have been explored. The findings of the study help us to understand how decisions are made with respect with to deviations from a mental anchor point and through the process of evaluation of losses and gains. 相似文献
108.
109.
M Y I?can 《Journal of forensic sciences》1988,33(6):1473-1476
Dr. Wilton Marion Krogman was one of the major founders of physical and forensic anthropology in the United States. His extraordinary career spanned nearly six decades, and he was universally admired and respected for his scholarship, teaching, research, wit, and humanity. While studies based on human skeletal remains have long been used to assist the medicolegal system, the late Dr. Krogman can be credited with uniting these areas into the discipline of forensic anthropology. His "Guide to the Identification of Human Skeletal Material" (1939) in the F.B.I. Law Enforcement Bulletin became the foundation of this discipline; his monumental book The Human Skeleton in Forensic Medicine (updated with the author in 1986) solidified its establishment. The purpose of this paper is to pay tribute to this great man and outline his influence on the development and advancement of forensic anthropology. 相似文献
110.