全文获取类型
收费全文 | 1211篇 |
免费 | 24篇 |
国内免费 | 12篇 |
专业分类
教育 | 782篇 |
科学研究 | 221篇 |
各国文化 | 23篇 |
体育 | 102篇 |
综合类 | 5篇 |
文化理论 | 6篇 |
信息传播 | 108篇 |
出版年
2023年 | 9篇 |
2022年 | 11篇 |
2021年 | 26篇 |
2020年 | 30篇 |
2019年 | 41篇 |
2018年 | 47篇 |
2017年 | 72篇 |
2016年 | 44篇 |
2015年 | 36篇 |
2014年 | 48篇 |
2013年 | 176篇 |
2012年 | 49篇 |
2011年 | 47篇 |
2010年 | 50篇 |
2009年 | 37篇 |
2008年 | 44篇 |
2007年 | 38篇 |
2006年 | 29篇 |
2005年 | 33篇 |
2004年 | 19篇 |
2003年 | 25篇 |
2002年 | 25篇 |
2001年 | 26篇 |
2000年 | 24篇 |
1999年 | 27篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 17篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1975年 | 10篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1971年 | 7篇 |
1970年 | 4篇 |
排序方式: 共有1247条查询结果,搜索用时 78 毫秒
31.
Zachary Y.Kerr Aliza K.Nedimyer Melissa C.Kay Avinash Chandran Paula Gildner K.Hunter Byrd Juliet K.Haarbauer-Krupa Johna K.Register-Mihalik 《运动与健康科学(英文)》2021,10(2):113-121
Background:Developing appropriate concussion prevention and management paradigms in middle school(MS)settings requires understanding parents’general levels of concussion-related knowledge and attitudes.This study examined factors associated with concussion-symptom knowledge and care-seeking attitudes among parents of MS children(aged 10-15 years).Methods:A panel of 1224 randomly selected U.S.residents,aged ≥18 years and identifying as parents of MS children,completed an online questionnaire capturing parental and child characteristics.The parents’concussion-symptom knowledge was measured using 25 questions,with possible answers being“yes”,“maybe”,and“no”.Correct answers earned 2 points,“maybe”answers earned 1 point,and incorrect answers earned 0 point(range:0-50;higher scores=better knowledge).Concussion care-seeking attitudes were also collected using five 7-point scale items(range:5-35;higher scores=more positive attitudes).Multivariable ordinal logistic regression models identified predictors of higher scores.Models met proportional odds assumptions.Adjusted odds ratios(aORs)with 95%confidence intervals(95%CIs)(excluding 1.00)were deemed statistically significant.Results:Median scores were 39(interquartile range:32-44)for symptom knowledge and 32(interquartile range:28-35)for care-seeking attitude.In multivariable models,odds of better symptom knowledge were higher in women vs.men(aOR=2.28;95%CI:1.71-3.05),white/non-Hispanics vs.other racial or ethnic groups(aOR=1.88;95%CI:1.42-2.49),higher parental age(10-year-increase aOR=1.47;95%CI:1.26-1.71),and greater competitiveness(10%-scale-increase aOR=1.24;95%CI:1.13-1.36).Odds of more positive care-seeking attitudes were higher in white/non-Hispanics vs.other racial or ethnic groups(aOR=1.45;95%CI:1.06-1.99)and in older parental age(10-year-increase aOR=1.24;95%CI:1.05-1.47).Conclusion:Characteristics of middle school children’s parents(e.g.,sex,race or ethnicity,age)are associated with their concussion-symptom knowledge and care-seeking attitudes.Parents’variations in concussion knowledge and attitudes warrant tailored concussion education and prevention. 相似文献
32.
余海波 《呼伦贝尔学院学报》2006,14(2):43-46
数学与哲学有着许多的内在联系,数学定律中蕴含着哲学,同时哲学又指导着数学的发展。把辨证唯物主义寓于数学教学之中,运用哲学原理指导数学学习,使学生能在理解和掌握所学数学知识的同时,理解和掌握辩证唯物主义的精髓,逐步做到主动改进方法, 增强能力,从本质上提高数学学习的水平和质量。 相似文献
33.
34.
Children with learning disabilities in four types of special education settings were compared in terms of social acceptance, number of friends, quality of relationship with best friends, self‐concept, loneliness, depression, social skills, and problem behaviors. Two of the placements (In‐Class Support and Resource Room) were for children with mild to moderate learning disabilities and involved between 30 and 90 minutes of special education per school day. The other two placements (Inclusion Class and Self‐Contained Special Education Class) were designated for children with severe learning disabilities and involved at least a half‐day of special education. Children in the more inclusive placements had more positive social and emotional functioning. Children receiving In‐Class Support were more accepted by peers, had higher self‐perceptions of mathematics competence, and fewer problem behaviors than children receiving Resource Room Support. Children in Inclusion Classes had more satisfying relationships with their best school friends, were less lonely, and had fewer problem behaviors than children in Self‐Contained Special Education Classes. 相似文献
35.
Verbal intelligence, English-language skills, personality, and attitude scales were used as predictors of academic performance in 230 male and female arts students at the University of Hong Kong. A series of bivariate, multiple, and canonical correlation analyses were performed. The results showed that verbal intelligence and attitudes, excepting study orientation, were not predictive of performance. English-language skills had the most predictive value, accounting for about 10% of the variance of performance measures. Personality variables failed to predict performance when composite criterion measures (GPAs) were used; however, they proved to be of predictive value when results of individual academic subjects were used as criterion measures. The study points to the importance of using noncomposite criterion measures in prediction and of considering the cultural context of achievement. 相似文献
36.
37.
<正> 全国化工院校情报中心站第四届年会于1988年10月17日-21日在武汉化工学院召开。中心站21个成员单位的代表出席了会议。化工部情报所的有关同志参加了会议。湖北省及武汉市图书馆情报界的知名人士、武汉化工学院领导等均到会致词祝贺。年会的主要议程有:一、就高校情报工作的服务方向、情报有偿服务、情报教学等方面的改革进行了广泛的交流和探讨。华东化工学院和青岛化工学院的代表介绍了图书馆实行定编定岗、优化组合、工资包干和情报实行定额承包、面向企业的改革尝试,引起了代表们的极大兴趣和热烈讨论。 相似文献
38.
R. Dhananjayan T. Malati Y. Rupasree Vijay Kumar Kutala 《Indian journal of clinical biochemistry : IJCB》2015,30(3):263-270
The present work was aimed to study the association of one carbon genetic variants, hyperhomocysteinemia and oxidative stress markers, i.e., serum nitrite, plasma malondialdehyde (MDA) and glutathione (GSH) on intimal medial thickening (IMT) in patients with type 2 diabetes mellitus (T2D). A total number of 76 subjects from ACS Medical College and Hospital, Chennai, India were included in the study, i.e., Group I (n = 42) of T2D and Group II (n = 34) of age- and sex matched healthy controls. The glycated haemoglobin was measured by ion-exchange resin method; plasma homocysteine by Enzyme Linked Immunosorbant Assay method; serum nitrite (nitric oxide, NO), plasma MDA and GSH by spectrophotometric methods; the IMT by high frequency ultrasound. The polymorphisms of one carbon genetic variants were genotyped using polymerase chain reaction-restriction fragment length polymorphism and amplified fragment length polymorphism methods. Results indicate that methyltetrahydrofolate homocysteine methyl transferase (MTR) A2756G allele was found to be protective in T2D and the other variants were not significantly associated with T2D. Glutamate carboxypeptidase II (GCP II) C1561T (r = 0.34; p = 0.05) and methylene tetrahydrofolate reductase (MTHFR) C677T (r = 0.35; 0.04) showed positive correlation with plasma homocysteine in T2D cases. In this study, MTR A2756G allele was found to be protective in T2D; GCP II C1561T and MTHFR C677T showed positive association with plasma homocysteine in T2D cases. Among all the genetic variants, MTR A2756G was found influence IMT. RFC 1 G80A and TYMS 5′-UTR 2R3R showed synergistically interact with MTR A2756G in influencing increase in IMT. 相似文献
39.
Fengjiao Lyu Manqi Xu Yunfeng Cheng Jinghang Xie Jianghong Rao Sindy K. Y. Tang 《Biomicrofluidics》2015,9(4)
This paper describes a method for the quantitative detection of cells expressing BlaC, a β-lactamase naturally expressed by Mycobacterium tuberculosis, intended for the diagnosis of tuberculosis. The method is based on the compartmentalization of bacteria in picoliter droplets at limiting dilutions such that each drop contains one or no cells. The co-encapsulation of a fluorogenic substrate probe for BlaC allows the quantification of bacteria by enumerating the number of fluorescent drops. Quantification of 10 colony forming units per milliliter is demonstrated. Furthermore, the encapsulation of single cell in drops maintains the specificity of the detection scheme even when the concentration of bacteria that do not express BlaC exceeds that expressing BlaC by one million-fold. 相似文献
40.
H. A. Guidobaldi Y. Jeyaram C. A. Condat M. Oviedo I. Berdakin V. V. Moshchalkov L. C. Giojalas A. V. Silhanek V. I. Marconi 《Biomicrofluidics》2015,9(2)
Many self-propelled microorganisms are attracted to surfaces. This makes their dynamics in restricted geometries very different from that observed in the bulk. Swimming along walls is beneficial for directing and sorting cells, but may be detrimental if homogeneous populations are desired, such as in counting microchambers. In this work, we characterize the motion of human sperm cells ∼60 μm long, strongly confined to ∼25 μm shallow chambers. We investigate the nature of the cell trajectories between the confining surfaces and their accumulation near the borders. Observed cell trajectories are composed of a succession of quasi-circular and quasi-linear segments. This suggests that the cells follow a path of intermittent trappings near the top and bottom surfaces separated by stretches of quasi-free motion in between the two surfaces, as confirmed by depth resolved confocal microscopy studies. We show that the introduction of artificial petal-shaped corrugation in the lateral boundaries removes the tendency of cells to accumulate near the borders, an effect which we hypothesize may be valuable for microfluidic applications in biomedicine. 相似文献