全文获取类型
收费全文 | 10562篇 |
免费 | 292篇 |
专业分类
各国政治 | 397篇 |
工人农民 | 378篇 |
世界政治 | 712篇 |
外交国际关系 | 286篇 |
法律 | 6705篇 |
中国政治 | 67篇 |
政治理论 | 2221篇 |
综合类 | 88篇 |
出版年
2020年 | 102篇 |
2019年 | 155篇 |
2018年 | 191篇 |
2017年 | 219篇 |
2016年 | 212篇 |
2015年 | 161篇 |
2014年 | 182篇 |
2013年 | 942篇 |
2012年 | 215篇 |
2011年 | 263篇 |
2010年 | 211篇 |
2009年 | 266篇 |
2008年 | 268篇 |
2007年 | 269篇 |
2006年 | 262篇 |
2005年 | 241篇 |
2004年 | 234篇 |
2003年 | 243篇 |
2002年 | 235篇 |
2001年 | 423篇 |
2000年 | 366篇 |
1999年 | 294篇 |
1998年 | 158篇 |
1997年 | 122篇 |
1996年 | 136篇 |
1995年 | 132篇 |
1994年 | 133篇 |
1993年 | 134篇 |
1992年 | 232篇 |
1991年 | 251篇 |
1990年 | 240篇 |
1989年 | 248篇 |
1988年 | 225篇 |
1987年 | 223篇 |
1986年 | 262篇 |
1985年 | 256篇 |
1984年 | 229篇 |
1983年 | 214篇 |
1982年 | 151篇 |
1981年 | 127篇 |
1980年 | 113篇 |
1979年 | 151篇 |
1978年 | 85篇 |
1977年 | 111篇 |
1976年 | 95篇 |
1975年 | 71篇 |
1974年 | 89篇 |
1973年 | 83篇 |
1972年 | 78篇 |
1971年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
251.
252.
253.
Rizk IA Stokes CS Nelson MR 《Studies in Comparative International Development (SCID)》1982,17(2):74-86
Child mortality was analyzed in relation to 3 dimensions of reproductive behavior: birth intervals, additional children desired, and contraceptive use. Study data were drawn from a 1978 survey conducted in 2 predominantly rural governorates, Beheira and Kafr El-Sheikh, in lower Egypt. Within each governorate, 2 districts were selected on the basis of their distance from the capital of the governorate, agricultural output by major crops, percent of the population urban, infant mortality rate, and crude birthrate. Within each of the 4 districts, villages were randomly drawn from 3 strata: villages lacking any governmental services; villages with limited services (health center or primary school); and villages served by a combined unit center providing integrated services. A random sample of household heads was selected from household registration records of the provision office of each district. 1200 interviews were obtained from 685 households. Restriction of the sample to women with 1 or more live births, and the elimination of 13 cases with incomplete or inaccurate information, yielded 1010 cases for analysis. The basic measure of actual fertility was birth intervals. For the total sample and within each age category, cumulative fertility is higher the greater the number of child deaths. The data demonstrate a strong relationship between child mortality experience and cumulative fertility. The problem lies in interpreting such results. With some exceptions, birth intervals increased as expected with increasing parity. Women without child death experience displayed longer birth intervals than women who had not lost a child. With the single exception of the 7th parity women, all differences were statistically significant. The data fail to eliminate potential biological influences on subsequent fertility. With biological influences adequately controlled, no behavioral differences remained. Women who experienced child mortality desired greater numbers of additional children than women without child death experience. 19% of respondents were ever users of contraception, with women of low parity the least likely ever to have used contraception. 相似文献
254.
255.
256.
257.
258.
259.
In 1973 the United States Supreme Court ruled that abortion could be had practically on request during the first 3 months of pregnancy. This article discusses whether the decision led to more public support for that position, and where in the U.S. the increase in support has been most drastic. The most recent public opinion polls indicate about 60% public support legalized abortion, while it was only 45% before 1973. Support has also increased even if pregnancy is not judged to be detrimental to the mother's health, or if it is not the result of rape and/or incest, but even if it is simply requested for economic or purely personal reasons. People under 30, with college education, men and Protestants, seem to be the staunchest supporters of abortion on demand. There has also been an increase in the number of Catholics supporting abortion. Support for abortion increased in most states between 1969-1973, particularly in the West and in the Northwest. The fight to deny federal funds for abortion is still raging in Congress; some studies indicate that the religion of the legislators is the most powerful predictor of voting on abortion, and that the decision is a very personal one, and not easily altered by the lobbying of groups on either side. 相似文献
260.
Wheeler DR 《The Personnel journal》1979,58(6):374-5, 404