全文获取类型
收费全文 | 2303篇 |
免费 | 40篇 |
国内免费 | 11篇 |
专业分类
教育 | 1436篇 |
科学研究 | 183篇 |
各国文化 | 18篇 |
体育 | 501篇 |
综合类 | 2篇 |
文化理论 | 38篇 |
信息传播 | 176篇 |
出版年
2023年 | 15篇 |
2022年 | 41篇 |
2021年 | 59篇 |
2020年 | 68篇 |
2019年 | 99篇 |
2018年 | 148篇 |
2017年 | 138篇 |
2016年 | 141篇 |
2015年 | 69篇 |
2014年 | 83篇 |
2013年 | 320篇 |
2012年 | 103篇 |
2011年 | 97篇 |
2010年 | 97篇 |
2009年 | 74篇 |
2008年 | 87篇 |
2007年 | 73篇 |
2006年 | 75篇 |
2005年 | 70篇 |
2004年 | 53篇 |
2003年 | 39篇 |
2002年 | 44篇 |
2001年 | 35篇 |
2000年 | 26篇 |
1999年 | 24篇 |
1998年 | 26篇 |
1997年 | 20篇 |
1996年 | 10篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 16篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 12篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1975年 | 12篇 |
1974年 | 7篇 |
1973年 | 5篇 |
1972年 | 4篇 |
排序方式: 共有2354条查询结果,搜索用时 15 毫秒
61.
62.
Serap ?uhadar Mehmet K?seo?lu Yasemin ?inpolat Güler Bu?dayc? Murat Usta Tuna Semerci 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2016,26(1):53-60
Introduction
Extremely high glucose concentrations have been shown to interfere with creatinine assays especially with Jaffe method in peritoneal dialysate. Because diabetes is the fastest growing chronic disease in the world, laboratories study with varying glucose concentrations. We investigated whether different levels of glucose spiked in serum interfere with 21 routine chemistry and thyroid assays at glucose concentrations between 17-51 mmol/L.Materials and methods
Baseline (group I) serum pool with glucose concentration of 5.55 (5.44-5.61) mmol/L was prepared from patient sera. Spiking with 20% dextrose solution, sample groups were obtained with glucose concentrations: 17.09, 34.52, and 50.95 mmol/L (group II, III, IV, respectively). Total of 21 biochemistry analytes and thyroid tests were studied on Abbott c8000 and i2000sr with commercial reagents. Bias from baseline value was checked statistically and clinically.Results
Creatinine increased significantly by 8.74%, 31.66%, 55.31% at groups II, III, IV, respectively with P values of < 0.001. At the median glucose concentration of 50.95 mmol/L, calcium, albumin, chloride and FT4 biased significantly clinically (-0.85%, 1.63%, 0.65%, 7.4% with P values 0.138, 0.214, 0.004, < 0.001, respectively). Remaining assays were free of interference.Conclusion
Among the numerous biochemical parameters studied, only a few parameters are affected by dramatically increased glucose concentration. The creatinine measurements obtained in human sera with the Jaffe alkaline method at high glucose concentrations should be interpreted with caution. Other tests that were affected with extremely high glucose concentrations were calcium, albumin, chloride and FT4, hence results should be taken into consideration in patients with poor diabetic control.Key words: assay interference, glucose interference, preanalytical phase, creatinine, Jaffe kinetic assay, thyroid function tests 相似文献63.
高吕和 《北京工业职业技术学院学报》2007,6(2):39-41
从图论的角度讨论了静态最优路径的算法及其复杂度,在此基础上对停车诱导功能需求进行研究,提出了停车场内部诱导系统的设计思路和方法. 相似文献
64.
Do preadolescent sport self-concepts influence subsequent sport performance? Longitudinal data (Grades 3, 4, and 6) for young boys and girls (N= 1,135; mean age = 9.67) were used to test reciprocal effects model (REM) predictions that sport self-concept is both a cause and a consequence of sport accomplishments. Controlling prior sport performance (performance-based measures and teacher assessments), prior sport self-concept had positive effects on subsequent sport performance in both Grade 4 and Grade 6 and for both boys and girls. Coupled with previous REM studies of adolescents in the academic domain, this first test for preadolescents in the sport domain supports the generalizability of REM predictions over gender, self-concept domain, preadolescent ages, and the transition from primary to secondary school. 相似文献
65.
Re-referral to child protective services: the influence of child, family, and case characteristics on risk status 总被引:2,自引:0,他引:2
INTRODUCTION: This study examines child, family, and case characteristics that impact rates of re-referral to Child Protective Services (CPS) using data on all closed CPS investigations for the state of Rhode Island between 2001 and 2004. METHOD: A longitudinal dataset of all referrals to CPS was created using state submissions to the National Child Abuse and Neglect Data System (NCANDS). After excluding children whose initial CPS investigation resulted in removal from the home, a Cox proportional hazards model was tested to examine factors impacting the likelihood of re-referral. RESULTS: Consistent with other research in this area, the initial 6-month period following case disposition is the period of greatest risk of re-referral. Approximately 13% of cases experienced a recurrent allegation during the first 6-month period; an additional 14% experienced a re-referral over the following 12-month period; 7% during the next 12-month period. Family poverty was the strongest predictor of re-referral, though a number of child and case characteristics were significantly related to recurrence. Cases that were substantiated at index were significantly less likely to result in a new allegation, though substantiated cases of physical abuse or those receiving post-investigation services were at higher risk. CONCLUSIONS: Children from families facing multiple stressors (e.g., low SES, parental substance abuse child disability) are at highest risk of re-referral to CPS and may benefit from the development of preventive services targeted immediately following case closings within CPS. 相似文献
66.
Mariola C. Gremmen Christian Berger Allison M. Ryan Christian E.G. Steglich René Veenstra Jan K. Dijkstra 《Child development》2019,90(2):e192-e211
This study examined to what extent adolescents’ and their friends’ risk behaviors (i.e., delinquency and alcohol use) hinder or promote their academic achievement (grade point average [GPA]), and vice versa. Longitudinal data were used (N = 1,219 seventh- to ninth-grade adolescents; Mage = 13.69). Results showed that risk behaviors negatively affected adolescents’ GPA, whereas GPA protected against engaging in risk behaviors. Moreover, adolescents tended to select friends who have similar behaviors and friends’ behaviors became more similar over time (same-behavior selection and influence). Furthermore, although same-behavior effects seemed to dominate, evidence was found for some cross-behavior selection effects and a tendency in seventh grade for cross-behavior influence effects. Concluding, it is important to investigate the interplay between different behaviors with longitudinal social network analysis. 相似文献
67.
Patrice Milewski Christian Ydesen 《Paedagogica Historica: International Journal of the History of Education》2019,55(3):371-390
ABSTRACTThis article compares and contrasts the use of mental testing and the formation of educational streaming in Denmark and Ontario during the interwar years. In this sense, the article adds nuances to the meaning of internationalism as well as contributing to our knowledge about how ideas of testing practices circulated among countries and continents. One way ideas and practices circulated was via informal networks promoted by the education traveller. Key proponents of mental testing in both Denmark and Ontario travelled to continental Europe, England, and the United States studying and observing the practices and institutional arrangements associated with educational streaming. Our main findings are that the processes used to implement mental testing in the two countries differed significantly. Mental testing was implemented much later in Denmark than in Ontario. This was due to different contextual, cultural, and historical factors that promoted changes to the existing system, or, alternatively, represented a barrier or even obstructed changes to it. Nevertheless, mental testing was implemented in both education systems as a relatively coherent technology rooted in transnational movements and exchange, but was attended by highly different practices and local meaning-making. 相似文献
68.
Tarchi Christian Surian Alessio Daiute Colette 《European Journal of Psychology of Education - EJPE》2019,34(4):873-894
European Journal of Psychology of Education - This study analyzed study abroad students’ orientations to cultural differences as assessed with mixed methods, including traditional... 相似文献
69.
70.
Benjamin Rubeli Esther Oswald Achim Conzelmann Jürg Schmid Stefan Valkanover 《Physical Education & Sport Pedagogy》2020,25(4):346-360
ABSTRACTBackground: Schoolchildren’s personality development is considered a central goal of physical education (PE). With regard to the relationship between psychological well-being and global self-esteem over the life course, the promotion of positive self-esteem is an issue of particular significance. Past research revealed that PE taught with an individualized teacher frame of reference (iTFR) and a reflexive teaching style is associated with positive effects on facets of children’s perceived sports competence. However, it remains an open question whether this teaching styles has the potential to promote positive self-esteem.Purpose: The present study investigated whether a five-month teacher training, aimed to enhance the teachers’ iTFR and their reflexive teaching style in PE, has a positive effect on students’ perceived sports competence and their global self-esteem. To analyse the implementation quality, changes in students’ perceived iTFR and perceived reflexive teaching style were investigated.Method: A total of 21 teachers were assigned to either an intervention group (n?=?13), receiving the five-month teacher training, or a control group (n?=?8) consisting of regular teaching without teacher training. The teacher training encompassed five three-hour consecutive sessions during which the teachers acquired theoretical and practical knowledge about the promotion of competence perceptions in PE with a reflexive teaching style and an iTFR. Between the sessions, the teachers were instructed to implement an iTFR and a reflexive teaching style into their own PE classes. To evaluate the effects of the teacher training, their students’ (N?=?315, 53.7% girls, Mage?=?13.2 y, SDage?=?1.3 y) perceived teaching style (iTFR and reflexive teaching), perceived sports competence and global self-esteem were measured with paper-pencil questionnaires at three measurement points (pre, post and follow-up).Findings: Linear mixed effect models showed that students of the intervention group reported an increase in their teachers’ reflexive teaching style, but there were no changes with regard to iTFR. With regard to students’ perceived sports competence and global self-esteem, there were significant interaction effects between time and group over a period of eight months (from pre-test to follow-up), indicating positive effects on these self-concept dimensions due to the teacher training.Conclusion: The present study indicates that a long-term teacher training supports PE teachers to implement teaching styles with the aim to promote students’ self-concept. Furthermore, the findings lead to the assumption that a more pronounced iTFR in combination with an enhanced reflexive teaching style has the potential to positively influence schoolchildren’s perceived sports competence and global self-esteem. 相似文献