全文获取类型
收费全文 | 14051篇 |
免费 | 51篇 |
国内免费 | 1篇 |
专业分类
教育 | 10610篇 |
科学研究 | 1499篇 |
各国文化 | 21篇 |
体育 | 572篇 |
综合类 | 8篇 |
文化理论 | 404篇 |
信息传播 | 989篇 |
出版年
2022年 | 26篇 |
2021年 | 40篇 |
2020年 | 54篇 |
2019年 | 72篇 |
2018年 | 2237篇 |
2017年 | 2166篇 |
2016年 | 1644篇 |
2015年 | 192篇 |
2014年 | 207篇 |
2013年 | 555篇 |
2012年 | 299篇 |
2011年 | 774篇 |
2010年 | 896篇 |
2009年 | 469篇 |
2008年 | 697篇 |
2007年 | 1191篇 |
2006年 | 116篇 |
2005年 | 422篇 |
2004年 | 486篇 |
2003年 | 392篇 |
2002年 | 164篇 |
2001年 | 32篇 |
2000年 | 64篇 |
1999年 | 57篇 |
1998年 | 25篇 |
1997年 | 27篇 |
1996年 | 22篇 |
1995年 | 20篇 |
1994年 | 18篇 |
1993年 | 16篇 |
1992年 | 23篇 |
1991年 | 39篇 |
1990年 | 46篇 |
1989年 | 35篇 |
1988年 | 33篇 |
1987年 | 18篇 |
1986年 | 30篇 |
1985年 | 38篇 |
1984年 | 31篇 |
1983年 | 23篇 |
1982年 | 22篇 |
1981年 | 22篇 |
1980年 | 19篇 |
1979年 | 26篇 |
1978年 | 26篇 |
1977年 | 19篇 |
1976年 | 18篇 |
1974年 | 13篇 |
1971年 | 16篇 |
1968年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 531 毫秒
1.
David Kaldewey 《Minerva》2018,56(2):161-182
This article analyzes the concept of “grand challenges” as part of a shift in how scientists and policymakers frame and communicate their respective agendas. The history of the grand challenges discourse helps to understand how identity work in science and science policy has been transformed in recent decades. Furthermore, the question is raised whether this discourse is only an indicator, or also a factor in this transformation. Building on conceptual history and historical semantics, the two parts of the article reconstruct two discursive shifts. First, the observation that in scientific communication references to “problems” are increasingly substituted by references to “challenges” indicates a broader cultural trend of how attitudes towards what is problematic have shifted in the last decades. Second, as the grand challenges discourse is rooted in the sphere of sports and competition, it introduces a specific new set of societal values and practices into the spheres of science and technology. The article concludes that this process can be characterized as the sportification of science, which contributes to self-mobilization and, ultimately, to self-optimization of the participating scientists, engineers, and policymakers. 相似文献
2.
3.
4.
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
5.
6.
7.
8.
Anthony J. Sadar 《Science & Education》2018,27(1-2):233-235
9.
Harry F. Dorrell Joseph M. Moore Mark F. Smith Thomas I. Gee 《Journal of sports sciences》2019,37(1):67-73
This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R2 values of >0.85 for all variables excluding deadlift mean velocity (R2 = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance. 相似文献
10.