全文获取类型
收费全文 | 467篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
教育 | 299篇 |
科学研究 | 85篇 |
各国文化 | 2篇 |
体育 | 49篇 |
综合类 | 5篇 |
文化理论 | 4篇 |
信息传播 | 28篇 |
出版年
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 15篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 16篇 |
2013年 | 67篇 |
2012年 | 16篇 |
2011年 | 23篇 |
2010年 | 10篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 16篇 |
2006年 | 9篇 |
2005年 | 9篇 |
2004年 | 12篇 |
2003年 | 14篇 |
2002年 | 11篇 |
2001年 | 16篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1992年 | 5篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1967年 | 2篇 |
1960年 | 2篇 |
1957年 | 2篇 |
1947年 | 2篇 |
1934年 | 2篇 |
排序方式: 共有472条查询结果,搜索用时 292 毫秒
21.
Stephanie M. Curenton Shana E. Rochester Jacqueline Sims Nneka Ibekwe-Okafor Iheoma U. Iruka Arlene G. García-Miranda Jessica Whittaker 《Child development》2022,93(3):681-698
This study used secondary data from the My Teaching Partner-Math/Science 2013–2016 randomized control trial to explore whether equitable sociocultural classroom interactions (see Curenton et al., 2019) were associated with the skills of 105 four- and five-year-olds (52% boys; drawn from 20 unique video recordings of preschool teachers/classrooms; 43% were Black, Latine, Asian, or other racially marginalized learners). Equitable interactions predicted children's skills with effect sizes ranging from small (0.01–0.44) to large (1.00). Moderation analyses revealed that when classrooms had more racially marginalized learners, teachers’ use of equitable disciplinary and personalized learning practices were associated with higher executive functioning gains across prekindergarten. Findings illustrate how classroom composition can be a key indicator between equitable classroom interactions and young children's early skills. 相似文献
22.
Ajay Kumar D. H. Shah M. G. R. Rajan U. R. Thakare S. M. Sharma 《Indian journal of clinical biochemistry : IJCB》1992,7(2):159-164
An external quality assessment was conducted to assess the performance of various laboratories for RIA of thhyroid related
hormones in two phases. In the first phase thirty five laboratories participated. At the end of first phase a meeting cum
workshop was organised to discuss the results of first phase, difficultires faced by the participants and pinpoint the short
oming. A second phase was then initiated with an objective of improvement in the performance, if any, where twelve samples
from four pools were distributed to twenty four laboratories who participated for the second phase. The overall return of
the results increased significantly from 71.8% (1586/2208) for the first phase to 92.4% (732/792) for the second phase. The
inter laboratory %CV for T3, T4 and TSH were lower during the second phase (30.6%, 19.0% and 31.6% respectively) as compared to those observed during first
phase (36.3%, 22.7% and 52.8% respectively). Similarly, there was an improvement in reproducibility of ALTM as %CV for T3, T4 and TSH decreased from 6.0%, 9.8% and 13.4% respectively to 4.5%, 4.6% and 8.5% respectively. The individual performances
of the participating laboratories viz. bias, variability of bias and imprecision also showed a trend towards improvement as
percent laboratories having desirable or acceptable results for T3, T4 and TSH increased from 10.7%, 60.7% and 0.0% respectively to 20.8%, 66.7% and 22.2% respectively. External quality assessment
thus appears to be beneficial in assessing the performane of a laboratory in comfparison with other laboratories and indeed
helps in improving the performance. 相似文献
23.
The transport of thermal energy in thermodynamics is described as the product of entropy flow and of the absolute temperature, in analogy to the volume flow and pressure in oil hydraulics and to electric charge flow (= current) and voltage in electronics. Bond graphs are shown to be especially suitable to describe the splitting of applied thermal energy into internal energy and external mechanical work. Transformers and the 0- and 1-junctions of Paynter can illustrate various entropy flow processes, including Carnot engines and heat exchangers. Entropy flow in heat conduction is distinguished from entropy convection, or transport by moving mass, where the entropy/temperature characteristic or equation of state is important. Irreversibilities are represented by impedance transformers reducing temperature and increasing entropy flow but conserving power. 相似文献
24.
Meena Desai U. M. Donde M. Ikram Khatkhatay 《Indian journal of clinical biochemistry : IJCB》2001,16(1):127-131
Baseline data available on the excretory profiles of estrone giucuronide (E1G), pregnanediol glucuronide (PdG) and luteinising hormone (LH) on human menstrual cycles (n=104) was retrospectively analysed
for identifying the limits of fertile period (FP) to be used as natural method of family planning. The limits of fertile period
are suggested based on centile distribution of E1G and PdG levels during defined phase of menstrual cycle. Two approaches, which do not involve any mathematical calculation
are suggested. In approach A, fertile period is said to have started when E1G value of 35 ng/ml is reached and is said to have ended when the PdG value of 2 μg/ml on two consecutive days is obtained.
The criteria were applied to 30 test cycles in whom authentic fertile period was identified based on excretory profiles of
E1G, PdG and LH throughout the menstrual cycles. When approach A was followed the authentic fertile period was covered in 27
cycles giving an accuracy of 90% with a mean fertile period length of 9.11+1.9 days. In approach B, the cut off limit of E1G value was increased to 55 ng/ml in order to reduce the days of abstinence. Though the length of the fertile period was reduced
to 7.2+1.5 days the accuracy of the approach was 66.6%. Thus the approach A which has accuracy of 90% may appeal to determined
couples who wish to practice family planning by periodic abstinence or restrict the use of barrier methods. 相似文献
25.
Zhouchao Wei Amin Yousefpour Hadi Jahanshahi Uǧur Erkin Kocamaz Irene Moroz 《Journal of The Franklin Institute》2021,358(1):814-833
Having found hidden hyperchaos in a 5D self-exciting homopolar disc dynamo, we study the existence of a Hopf bifurcation, which leads to unstable limit cycles bifurcating from a stable equilibrium. Hidden chaos with only stable equilibria can be observed from the Hopf bifurcation: a typical way to enable hidden attractors to be located. We then provide a new fuzzy controller, and a fast fuzzy disturbance observer, based on terminal sliding mode control for synchronization of the hyperchaotic system. Fuzzy inference is considered to weaken the chattering phenomena. Using Lyapunov stability theory, the stability of the closed-loop system is proved. Finally, simulations of synchronization are illustrated to show the efficient performance of the designed control method via external disturbances and dynamic uncertainties. 相似文献
26.
Bonacci J Saunders PU Alexander M Blanch P Vicenzino B 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(1):59-71
Running is the most important discipline for Olympic triathlon success. However, cycling impairs running muscle recruitment and performance in some highly trained triathletes; though it is not known if this occurs in elite international triathletes. The purpose of this study was to investigate the effect of cycling in two different protocols on running economy and neuromuscular control in elite international triathletes. Muscle recruitment and sagittal plane joint angles of the left lower extremity and running economy were compared between control (no preceding cycle) and transition (preceded by cycling) runs for two different cycle protocols (20-minute low-intensity and 50-minute high-intensity cycles) in seven elite international triathletes. Muscle recruitment and joint angles were not different between control and transition runs for either cycle protocols. Running economy was also not different between control and transition runs for the low-intensity (62.4 +/- 4.5 vs. 62.1 +/- 4.0 ml/min/kg, p > 0.05) and high-intensity (63.4 +/- 3.5 vs. 63.3 +/- 4.3 ml/min/kg, p > 0.05) cycle protocols. The results of this study demonstrate that both low- and high-intensity cycles do not adversely influence neuromuscular control and running economy in elite international triathletes. 相似文献
27.
Sarı Uğur Pektaş Hüseyin Miraç Şen Ömer Faruk Çelik Harun 《Education and Information Technologies》2022,27(5):6669-6689
Education and Information Technologies - The need to benefit from information technologies in the twenty-first century digital age is increasing in all economies to overcome problems and... 相似文献
28.
The dissection room experience: A factor in the choice of organ and whole body donation—A Nigerian survey
下载免费PDF全文
![点击此处可从《Anatomical sciences education》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Emeka G. Anyanwu Emmanuel N. Obikili Augustine U. Agu 《Anatomical sciences education》2014,7(1):56-63
The psychosocial impact of human dissection on the lives of medical and health science students has been noted. To assess the impact of the dissection room experience on one's willingness to become a whole body and organ donor, the attitudes of 1,350 students and professionals from the medical, health, and non‐health related disciplines to body and organ donation were studied. The participants were broken into categories according to degree of exposure to human dissection. Participants who were never exposed to the dissection experience showed more willingness to donate their bodies than those who were exposed. With the exception of the physiotherapy department, the students and professionals from the health science departments who were exposed to the dissection room but never engaged in dissection showed the most unwillingness to donate their bodies (P < 0.001). An unwillingness to donate oneself was noted as one of the negative impacts associated with exposure to the dissection room. Willingness to donate an organ correlated positively with the level of exposure to the dissection room (P < 0.001). Most of the reasons for unwillingness were traceable to negative perceptions of the dissection room as a result of poor and disrespectful management of the human cadavers. Anat Sci Educ. 7: 56–63. © 2013 American Association of Anatomists. 相似文献
29.
30.