全文获取类型
收费全文 | 12362篇 |
免费 | 271篇 |
专业分类
各国政治 | 656篇 |
工人农民 | 515篇 |
世界政治 | 874篇 |
外交国际关系 | 471篇 |
法律 | 7573篇 |
中国共产党 | 1篇 |
中国政治 | 86篇 |
政治理论 | 2392篇 |
综合类 | 65篇 |
出版年
2020年 | 134篇 |
2019年 | 188篇 |
2018年 | 245篇 |
2017年 | 250篇 |
2016年 | 255篇 |
2015年 | 170篇 |
2014年 | 246篇 |
2013年 | 1323篇 |
2012年 | 278篇 |
2011年 | 296篇 |
2010年 | 265篇 |
2009年 | 281篇 |
2008年 | 330篇 |
2007年 | 329篇 |
2006年 | 317篇 |
2005年 | 267篇 |
2004年 | 288篇 |
2003年 | 276篇 |
2002年 | 221篇 |
2001年 | 544篇 |
2000年 | 467篇 |
1999年 | 392篇 |
1998年 | 171篇 |
1997年 | 152篇 |
1996年 | 121篇 |
1995年 | 118篇 |
1994年 | 120篇 |
1993年 | 101篇 |
1992年 | 227篇 |
1991年 | 272篇 |
1990年 | 261篇 |
1989年 | 250篇 |
1988年 | 242篇 |
1987年 | 277篇 |
1986年 | 246篇 |
1985年 | 229篇 |
1984年 | 216篇 |
1983年 | 195篇 |
1982年 | 135篇 |
1981年 | 151篇 |
1980年 | 100篇 |
1979年 | 193篇 |
1978年 | 124篇 |
1977年 | 96篇 |
1976年 | 81篇 |
1975年 | 114篇 |
1974年 | 125篇 |
1973年 | 131篇 |
1972年 | 93篇 |
1971年 | 90篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Two rare ADA phenotypes were observed in a German mother and her child. These phenotypes may be due to the allele ADA *9 previously found in Bulgaria. 相似文献
972.
A case is presented in which a 44-year-old man stabbed himself in the heart with a kitchen knife, then changed his bloody clothes, and ate lunch with his aunt, who did not notice the event. After 2 h he died of cardiac tamponade. 相似文献
973.
974.
975.
Members of married couples rated how ideal communal, exchange, and equality rules were for their marriages. They also reported on whether they and their spouses followed each norm in general in their marriages and in the domains of housework and child care. Both men and women considered a communal norm to be more ideal than the other norms and reported that they and their spouse followed a communal norm to a greater extent than an exchange or equality rule, both in general and in the domains of housework and child care. In addition, links between reports of actual division of labor in each domain, as well as reports of norm use, and perceived fairness of the division of family work were examined. Greater inequalities in the division of labor were linked to decreased perceptions of fairness. Controlling for reports of division of labor, women's reports of the self and of the spouse following a communal norm were linked with increased perceptions of fairness as were women's reports of the spouse following an equality rule. In contrast, and again after controlling for reports of division of labor, women's reports of the self following an exchange rule and men's reports of the self and of the spouse following an exchange rule were associated with greater perceived unfairness of the division of family work. 相似文献
976.
Juvenile delinquency is a major public concern in the United States, and increasingly in many other industrialized countries. The last few years have seen a decline in officially recorded juvenile delinquency (Snyder, 1997). However, projections are that with the anticipated increase of the U.S. teenage population because of the echo baby boom generation, serious juvenile crime will substantially increase in the next few years (see Fox, 1996). 相似文献
977.
Frank H. Trinkl 《Policy Sciences》1972,3(2):163-176
Difficulties have been encountered in attempting to apply benefit-cost analysis to the problem of determining resource allocations among social programs, especially when there are multiple outcomes associated with each of the programs. Further complications result when program outcomes are characterized as counteractive: a specific allocation of resources to a program is likely to achieve a favorable impact regarding certain objectives while that allocation is also likely to have an unfavorable impact regarding other objectives. A model which promises to be useful in determining optimal resource allocations among programs having counteractive outcomes is presented. Two steps are required for the use of the model: (1) values, reflecting priorities, need to be assigned to the various objectives that programs are intended to accomplish and (2) an ensemble of probabilistic functions relating resources to program outcomes needs to be specified and combined to reflect the value of an ensemble of programs. In addition to determining optimal resource allocations, the model provides insights into the consequences of resource decisions based on noneconomic considerations. An example illustrates the major features of the model. 相似文献
978.
979.
980.