全文获取类型
收费全文 | 26357篇 |
免费 | 868篇 |
国内免费 | 12篇 |
专业分类
27237篇 |
出版年
2019年 | 256篇 |
2018年 | 314篇 |
2017年 | 349篇 |
2016年 | 394篇 |
2015年 | 309篇 |
2014年 | 337篇 |
2013年 | 1910篇 |
2012年 | 648篇 |
2011年 | 667篇 |
2010年 | 419篇 |
2009年 | 433篇 |
2008年 | 621篇 |
2007年 | 568篇 |
2006年 | 492篇 |
2005年 | 493篇 |
2004年 | 458篇 |
2003年 | 475篇 |
2002年 | 481篇 |
2001年 | 706篇 |
2000年 | 695篇 |
1999年 | 480篇 |
1998年 | 253篇 |
1992年 | 475篇 |
1991年 | 462篇 |
1990年 | 464篇 |
1989年 | 461篇 |
1988年 | 418篇 |
1987年 | 427篇 |
1986年 | 455篇 |
1985年 | 484篇 |
1984年 | 414篇 |
1983年 | 380篇 |
1982年 | 273篇 |
1981年 | 319篇 |
1980年 | 246篇 |
1979年 | 452篇 |
1978年 | 323篇 |
1977年 | 290篇 |
1976年 | 279篇 |
1975年 | 414篇 |
1974年 | 472篇 |
1973年 | 498篇 |
1972年 | 416篇 |
1971年 | 407篇 |
1970年 | 384篇 |
1969年 | 406篇 |
1968年 | 499篇 |
1967年 | 477篇 |
1966年 | 457篇 |
1958年 | 252篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Visual acuity for the detection of gratings at four orientations was measured for groups of ten boys and ten girls aged five to seven years, from the following four populations: Scots in Glasgow, Pakistanis in Glasgow, Gaels in Stornoway (Outer Hebrides) and East Anglians in Littleport (Cambridgeshire fenlands). The Glaswegians, both Scottish and Pakistani, showed the normal pattern of anisotropy, with poorest acuity for oblique orientations; the East Anglians showed no significant anisotropy; while the Gaels were unusual in showing poorest horizontal acuity. A group of fourteen Pakistani children in Stornoway differed slightly from a matched group of Gaels. The group differences bore little relation to the visual environments, and were probably due to genetic or cultural factors. The relatively poor horizontal acuity of the Gaels was not correlated with astigmatism. Sex differences were also found, with the boys showing higher mean acuity and a higher ratio between vertical and oblique acuity. 相似文献
52.
53.
54.
55.
56.
Recidivism data derived from various sources over a follow-up period of 1–11 yr, provided the basis for appraising the effectiveness of a comprehensive cognitive-behavioral treatment program for familial and nonfamilial child molesters. Unofficial records held by police and Children's Aid Societies proved to be the best data for estimating recidivism. These data revealed increases in recidivism with longer follow-up periods, but there were consistent advantages for the treated over the untreated patients. Men who had sexually abused the daughters of other people demonstrated the clearest treatment benefits. The younger offenders and those who had engaged in genital-genital contact with their victims were more likely to reoffend even if they were treated. Contrary to the expectations of behavior therapists, indices of deviant sexual preferences did not predict outcome. 相似文献
57.
58.
59.
60.