全文获取类型
收费全文 | 65874篇 |
免费 | 2618篇 |
国内免费 | 23篇 |
专业分类
68515篇 |
出版年
2020年 | 692篇 |
2019年 | 918篇 |
2018年 | 1208篇 |
2017年 | 1306篇 |
2016年 | 1313篇 |
2015年 | 926篇 |
2014年 | 1150篇 |
2013年 | 5070篇 |
2012年 | 2092篇 |
2011年 | 2153篇 |
2010年 | 1333篇 |
2009年 | 1296篇 |
2008年 | 1914篇 |
2007年 | 1897篇 |
2006年 | 1757篇 |
2005年 | 1549篇 |
2004年 | 1487篇 |
2003年 | 1364篇 |
2002年 | 1417篇 |
2001年 | 1993篇 |
2000年 | 1862篇 |
1999年 | 1459篇 |
1998年 | 712篇 |
1997年 | 646篇 |
1992年 | 1189篇 |
1991年 | 1099篇 |
1990年 | 1136篇 |
1989年 | 1054篇 |
1988年 | 1075篇 |
1987年 | 1021篇 |
1986年 | 1040篇 |
1985年 | 1050篇 |
1984年 | 891篇 |
1983年 | 848篇 |
1982年 | 655篇 |
1981年 | 635篇 |
1979年 | 1014篇 |
1978年 | 726篇 |
1977年 | 621篇 |
1976年 | 640篇 |
1975年 | 849篇 |
1974年 | 911篇 |
1973年 | 958篇 |
1972年 | 752篇 |
1971年 | 725篇 |
1970年 | 681篇 |
1969年 | 752篇 |
1968年 | 904篇 |
1967年 | 800篇 |
1966年 | 723篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Gábor L. Ambrus 《Zygon》2020,55(4):875-897
We are easily misguided as to the true nature of Facebook, and tend to treat it simply as a powerful technological instrument in the service of human intentions. We can, however, gain a better picture of it through recourse to the Jewish tradition of the golem, an image of human beings, created by them in a re-enactment of their own creation by God. It turns into a magic servant in modernity with an inherent dynamic running between its human and its subhuman characteristics. This dynamic is the main cause behind its becoming uncontrollable. In like manner, what is subhuman in Facebook serves its masters and functions under their total control, but also empowers Facebook's increasingly human operation, an algorithm-based capability which raises growing doubts about what counts as human. Facebook implies the crisis of humanity which coincides with the “death of God,” that is, the obsolescence of the idea of a divine creator. 相似文献
92.
93.
94.
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
95.
Cardiovascular reactivity to video game and mental arithmetic stressors was compared among three groups of men: aerobically trained mild hypertensives, untrained mild hypertensives, and a comparison group of untrained normotensives. Relative to the untrained hypertensives, the trained hypertensives reacted to the video game with marginally smaller systolic blood pressure and diastolic blood pressure, but there were no significant differences between these groups in reactivity during the mental arithmetic task. Comparisons between each hypertensive group and the normotensive group showed that blood pressure (BP) reactivity of normotensives during the video game was generally similar to that of trained hypertensives but smaller than that of untrained hypertensives. These results indicate that aerobic training, which has been found to reduce resting BP in mild hypertensives, may also exert a favorable impact in reducing cardiovascular reactivity of hypertensives during some stressful situations. 相似文献
96.
97.
98.
99.
100.