全文获取类型
收费全文 | 1602篇 |
免费 | 39篇 |
国内免费 | 7篇 |
专业分类
教育 | 931篇 |
科学研究 | 189篇 |
各国文化 | 9篇 |
体育 | 372篇 |
综合类 | 11篇 |
文化理论 | 6篇 |
信息传播 | 130篇 |
出版年
2024年 | 4篇 |
2020年 | 6篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 14篇 |
2012年 | 103篇 |
2011年 | 170篇 |
2010年 | 43篇 |
2009年 | 17篇 |
2008年 | 102篇 |
2007年 | 128篇 |
2006年 | 110篇 |
2005年 | 114篇 |
2004年 | 79篇 |
2003年 | 94篇 |
2002年 | 96篇 |
2001年 | 55篇 |
2000年 | 71篇 |
1999年 | 37篇 |
1998年 | 16篇 |
1997年 | 20篇 |
1996年 | 10篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1993年 | 17篇 |
1992年 | 33篇 |
1991年 | 25篇 |
1990年 | 31篇 |
1989年 | 19篇 |
1988年 | 11篇 |
1987年 | 16篇 |
1986年 | 21篇 |
1985年 | 29篇 |
1984年 | 24篇 |
1983年 | 16篇 |
1982年 | 15篇 |
1981年 | 9篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1959年 | 6篇 |
1958年 | 4篇 |
1957年 | 4篇 |
1955年 | 3篇 |
1938年 | 2篇 |
排序方式: 共有1648条查询结果,搜索用时 15 毫秒
1.
Aleksandar D.Kostic 《运动与健康科学(英文)》2020,9(3):201-202
Dear editor,In a recent longitudinal metagenomic study of the gut microbiome in elite athletes,1 we conducted multiple, repeated sampling from runners in the 2015 Boston Marathon as well as sedentary controls approximately 1 week prior to and 1 week after marathon day. We also analyzed an independent cohort of endurance athletes, including Olympic-caliber rowers。 相似文献
2.
Jacob MC Sturkenboom D 《Isis; an international review devoted to the history of science and its cultural influences》2003,94(2):217-252
The Natuurkundig Genootschap der Dames (Women's Society for Natural Knowledge), formally established by and for women, met regularly from 1785 to 1881 and sporadically until 1887. It challenges our stereotypes both of women and the physical sciences during the eighteenth century and of the intellectual interests open to women in the early European republics. This essay aims not simply to identify the society and its members but to describe their pursuits and consider what their story adds to the history of Western science. What does this society's existence tell us about the relationship between women and early science in general and about science and society in the Dutch setting in particular? Science and gender look rather different when observed through the activities of the immensely prosperous women of Middelburg, citizens of one of the most highly literate Western countries. The elite lives of the first-generation members of the women's society also offer us a glimpse into the early domestication of science, a process vital to its acceptance and assimilation. 相似文献
3.
联合国科教文组织(UNESCO)总情报规划处(PGI)于1982年12月7日至9日在巴黎的UNESCO总部召开了“情报处理和加工方法、规范和标准工作组第一次会议”。会议讨论了手工著录和机器著录之间以及它们各自体系中的兼容性问 相似文献
4.
Gruson D Ahn SA Rousseau MF 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2011,21(3):254-263
Heart failure (HF) is a frequent chronic disease in elderly people and represents a major health and economic burden. The accurate diagnosis of HF and the identification of high risk patients is mandatory to select the appropriate therapy and care. HF is associated to cardiac remodeling and inflammation and to the release of neurohormones. If natriuretic peptides remain the biomarkers of choice for the diagnosis and the prognosis of HF, several biomarkers related to cardiac remodeling and inflammation are available for testing and may add valuable information for the risk estimation of HF patients and for the selection of the most appropriated therapy. Furthermore, the quest for new efficient biomarkers of cardiac remodeling and inflammation is still ongoing and new candidates have been identified for a potential use in daily clinical practices. However, before their potential translation to routine parameters several challenges ranging form the analytical validation to the cost-effectiveness estimation should be considered. 相似文献
5.
6.
寄生性昆虫对寄主各种生命活动的干扰大小依种而异,有些能使寄主很快死亡,有些则对寄主的生存和繁殖无明显影响。很多寄生于不全变态类昆虫的寄生性昆虫,可将卵产在寄主几个或所有龄期的个体中。这些寄生物对同种寄主不同个体的影响大小则又和寄主开始被寄生时的龄期密切相关。自然界的蚜虫种群常常世代重叠,多个虫型、虫期混合出现。它们的寄生蜂能寄生除卵以外的所有龄期。对于这类寄主一寄生物系统,要了解和描述寄生物对寄主数量变动的影响大小,就必须考虑到寄生物产卵时对寄主龄期的选择和寄主开始被寄生时的龄期与受影响大小之间的关系。本工作详细观察了苦苣菜蚜Hyperomyzus lactucae(L.)在不同龄期被苦 相似文献
7.
本文对华东南(台湾,广东,海南)产的广东苏铁、台东苏铁及海南苏铁的形态学、解剖学和分类学问题、以及这几种苏铁的亲缘关系进行了讨论。本文附有检索表及图。 相似文献
8.
过去三十年中,在确定物质构造及其运动的明细组分方面,取得了巨大的进展。本之由一位西非物理学家阐明了我们现在对微观的、甚至更细微水平物质构成的了解。他强调加速器在其中的作用,并对可能存在如此多更基本的粒子表示惊讶。 相似文献
9.
Hu D 《Isis; an international review devoted to the history of science and its cultural influences》2007,98(3):539-557
Having introduced the theory of relativity from Japan, the Chinese quickly and enthusiastically embraced it during the May Fourth Movement, virtually without controversy. This unique passion for and openness to relativity, which helped advance the study of theoretical physics in China in the 1930s, was gradually replaced by imported Soviet criticism after 1949. During the Cultural Revolution, radical Chinese ideologues sponsored organized campaigns against Einstein and relativity, inflicting serious damage on Chinese science and scientific education. China's economic reforms in the late 1970s empowered scientists and presented them with the opportunity to rehabilitate Einstein and call for social democracy. Einstein has since become the symbol in China of the unity of science and democracy, the two eminent objectives of the May Fourth Movement that remain to be achieved in full. Using the reception of relativity as a case study, the essay also discusses issues involving the historical study of modern Chinese science. 相似文献
10.