全文获取类型
收费全文 | 7706篇 |
免费 | 39篇 |
国内免费 | 5篇 |
专业分类
教育 | 5310篇 |
科学研究 | 841篇 |
各国文化 | 56篇 |
体育 | 629篇 |
文化理论 | 38篇 |
信息传播 | 876篇 |
出版年
2022年 | 46篇 |
2021年 | 71篇 |
2020年 | 114篇 |
2019年 | 172篇 |
2018年 | 201篇 |
2017年 | 207篇 |
2016年 | 202篇 |
2015年 | 126篇 |
2014年 | 176篇 |
2013年 | 1382篇 |
2012年 | 167篇 |
2011年 | 171篇 |
2010年 | 145篇 |
2009年 | 148篇 |
2008年 | 173篇 |
2007年 | 165篇 |
2006年 | 136篇 |
2005年 | 122篇 |
2004年 | 115篇 |
2003年 | 105篇 |
2002年 | 110篇 |
2001年 | 128篇 |
2000年 | 150篇 |
1999年 | 138篇 |
1998年 | 67篇 |
1997年 | 60篇 |
1996年 | 77篇 |
1995年 | 73篇 |
1994年 | 76篇 |
1993年 | 72篇 |
1992年 | 129篇 |
1991年 | 110篇 |
1990年 | 100篇 |
1989年 | 140篇 |
1988年 | 94篇 |
1987年 | 97篇 |
1986年 | 93篇 |
1985年 | 120篇 |
1984年 | 94篇 |
1983年 | 97篇 |
1982年 | 94篇 |
1981年 | 90篇 |
1980年 | 85篇 |
1979年 | 98篇 |
1978年 | 98篇 |
1977年 | 75篇 |
1976年 | 78篇 |
1974年 | 63篇 |
1973年 | 62篇 |
1969年 | 46篇 |
排序方式: 共有7750条查询结果,搜索用时 15 毫秒
981.
Newborn infants who showed anthropometric signs of atypical patterns of fetal growth were compared with infants of appropriate growth on the Neonatal Behavioral Assessment Scale (NBAS) and on recently developed supplementary items. The sample consisted of lower-socioeconomic-status families in San Juan, Puerto Rico, and included teenage and older mothers. Infants with atypical patterns of fetal growth showed lower scores than did infants of appropriate growth on the NBAS orientation, motor, and reflex clusters and on 15 of the 18 supplementary scores. Gestational age was covaried and showed independent effects on 6 items. Differential effects on measures of state and autonomic function were also found when the effects of the ponderal index were held constant. The results suggested that neonatal behavior is related to multiple indices of fetal growth patterns that may indicate early versus late nutritional insult. Supplementary NBAS items do not improve the discriminability of the NBAS but may help explain the basis for observed group differences. 相似文献
982.
983.
A. T. Baines M. McVey B. Rybarczyk J. T. Thompson H. R. Wilkins 《CBE life sciences education》2004,3(1):62-68
We designed an interrupted case study to teach aerobic cellular respiration to major andnonmajor biology students. The case is based loosely on a real-life incident of rotenonepoisoning. It places students in the role of a coroner who must determine the cause ofdeath of the victim. The case is presented to the students in four parts. Each part isfollowed by discussion questions that the students answer in small groups prior to aclasswide discussion. Successive parts of the case provide additional clues to the mysteryand help the students focus on the physiological processes involved in aerobicrespiration. Students learn the information required to solve the mystery by reading thecourse textbook prior to class, listening to short lectures interspersed throughout thecase, and discussing the case in small groups. The case ends with small group discussionsin which the students are given the names and specific molecular targets of other poisonsof aerobic respiration and asked to determine which process (i.e., glycolysis, citric acidcycle, or the electron transport chain) the toxin disrupts. 相似文献
984.
This study reviews empirical data from the U.S. Census, American Community Survey (ACS) and academic journals to explore K-12 and higher educational outcomes pertaining to Southeast Asian American (SEAA) males. We argue that the empirical dismissal of SEAA males in social science research reinforces a longstanding agenda of structural neglect and invisibility. By disaggregating some of the existing data for Cambodian, Hmong, Laotian, and Vietnamese subgroups from the broader “Asian” group, we hope to repudiate the model minority myth and stereotypes related to masculinity. Findings revealed that SEAA males had K-12 and higher educational outcomes that contradict the standard conception of academic and financial success. We situate the findings of the article in a discussion of intersectionality and the mainstream cultural forces that impact SEAA males. 相似文献
985.
Marcia Eugenio-Gozalbo Raquel Pérez-López Juan-Carlos Tójar-Hurtado 《The Journal of environmental education》2020,51(3):246-255
ABSTRACTThe presence of learning gardens in Spain is growing, and the current scenario is highly diverse in relation to issues such as participatory models or purposes, among others. In the context of the 1st National Meeting on organic learning gardens, we convened eight expert practitioners in a focus group. Their discourse was analyzed through content analysis, after which four categories were selected for co-occurrence analyses. The most important questions for university garden-based practitioners in the country are presented, related to actors involved, functions that gardens fulfill, strengths of these educational resources, and requirements for their consolidation. 相似文献
986.
987.
988.
989.
990.
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