全文获取类型
收费全文 | 14706篇 |
免费 | 153篇 |
国内免费 | 7篇 |
专业分类
教育 | 9993篇 |
科学研究 | 1817篇 |
各国文化 | 337篇 |
体育 | 967篇 |
综合类 | 12篇 |
文化理论 | 172篇 |
信息传播 | 1568篇 |
出版年
2021年 | 105篇 |
2020年 | 141篇 |
2019年 | 220篇 |
2018年 | 923篇 |
2017年 | 964篇 |
2016年 | 726篇 |
2015年 | 233篇 |
2014年 | 255篇 |
2013年 | 1977篇 |
2012年 | 314篇 |
2011年 | 536篇 |
2010年 | 493篇 |
2009年 | 348篇 |
2008年 | 464篇 |
2007年 | 556篇 |
2006年 | 215篇 |
2005年 | 269篇 |
2004年 | 347篇 |
2003年 | 232篇 |
2002年 | 166篇 |
2001年 | 174篇 |
2000年 | 233篇 |
1999年 | 203篇 |
1998年 | 104篇 |
1997年 | 106篇 |
1996年 | 92篇 |
1995年 | 82篇 |
1993年 | 94篇 |
1992年 | 155篇 |
1991年 | 181篇 |
1990年 | 189篇 |
1989年 | 187篇 |
1988年 | 147篇 |
1987年 | 136篇 |
1986年 | 145篇 |
1985年 | 190篇 |
1984年 | 158篇 |
1983年 | 145篇 |
1982年 | 125篇 |
1981年 | 101篇 |
1980年 | 108篇 |
1979年 | 167篇 |
1978年 | 115篇 |
1977年 | 108篇 |
1976年 | 95篇 |
1975年 | 87篇 |
1974年 | 104篇 |
1973年 | 89篇 |
1971年 | 89篇 |
1968年 | 93篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Fadhaa A. Ghafil Bassim I. Mohammad Hussain S. Al-Janabi Najah R. Hadi Hayder A. Al-Aubaidy 《Indian journal of clinical biochemistry : IJCB》2021,36(1):81
Genetic variation in the angiotensin II type 1 receptor (AT1R) has an important effect on the outcome of acute coronary syndrome (ACS) initiated treatment with captopril. This study aims to investigate the impact of genetic polymorphism of AT1R (rs5186 and rs275651) on the ACS outcome in Iraqi patients treated with captopril. A total of 250 Iraqi individuals with ACS were included in this case—control study and they were divided into two study groups; Study group 1 included 125 participants who were prescribed captopril, 25 mg twice daily and study group 2 included 125 participants who received no captopril as part of their ACS treatment (control study). The AT1R gene (rs5186) CC genotype was found to be associated with ST-elevation myocardial infarction (STEMI) (Odd’s ratio (O.R) = 1.2, P = 0.7), while AC was associated with Non-ST-elevation myocardial infarction (NSTEMI) and unstable angina (UA) (O.R = 1.2, P = 0.8). AC genotype is more prone to have Percutaneous coronary intervention (PCI) after ACS attack (O.R = 1.2, P = 0.6). CC genotype had a risk to get less improvement (O.R = 1.6, P = 0.5), so might require higher doses of captopril during acute coronary insult. The AT1R gene (rs275651) AA genotype was associated with UA (O.R = 1.3, P = 0.9). AA and AT genotypes were more prone to have PCI after ACS attack (O.R = 3.9 P = 0.2, O.R = 3.5, P = 0.3 respectively) and thus requiring higher doses of captopril. We conclude that the AT1R rs5186, rs275651 genetic polymorphisms might partially affect the clinical outcome of ACS patients treated with captopril and might have captopril resistance which requires higher doses. 相似文献
3.
4.
Anthony J. Sadar 《Science & Education》2018,27(1-2):233-235
5.
ABSTRACT This article offers a textual analysis and semiotic reading of the Rich Kids of Tehran's (RKOT’s) Instagram page. Contributing to scholarship on Iranian youth media practices, this article interrogates how the RKOT navigate urban and rural space to engage in everyday processes of resistance against global and local systemic oppression. Grounding their visual representations on Instagram in historical and cultural context, the author questions how and when quotidian actions are transformed into political transgressions when posted on social media. This article emphasizes the RKOT's agency in shaping their brand by analyzing representations of gender performance, intertextuality, and national identity on Instagram. 相似文献
6.
In the IR field it is clear that the value of a system depends on the cost and benefit profiles of its users. It would seem obvious that different users would prefer different systems. In the TREC-9 filtering track, systems are evaluated by a utility measure specifying a given cost and benefit. However, in the study of decision systems it is known that, in some cases, one system may be unconditionally better than another. In this paper we employ a decision theoretic approach to find conditions under which an Information Filtering (IF) system is unconditionally superior to another for all users regardless of their cost and benefit profiles.It is well known that if two IF systems have equal precision the system with better recall will be preferred by all users. Similarly, with equal recall, better precision is universally preferred. We confirm these known results and discover an unexpected dominance relation in which a system with lower recall will be universally preferred provided its precision is sufficiently higher. 相似文献
7.
8.
9.
10.
Sports Engineering - A Monark cycle ergometer is a device globally used in physiological studies to measure the work and energy levels of exercising humans. In this paper a rope-braked cycle... 相似文献