全文获取类型
收费全文 | 142篇 |
免费 | 1篇 |
专业分类
化学 | 92篇 |
力学 | 3篇 |
数学 | 24篇 |
物理学 | 24篇 |
出版年
2019年 | 2篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 5篇 |
2012年 | 2篇 |
2011年 | 6篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 9篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1899年 | 1篇 |
1891年 | 2篇 |
1889年 | 2篇 |
1888年 | 1篇 |
1880年 | 2篇 |
1879年 | 2篇 |
排序方式: 共有143条查询结果,搜索用时 15 毫秒
121.
122.
123.
124.
Vicki N. Tariq Pamela Qualter Sian Roberts Yvon Appleby Lynne Barnes 《International Journal of Mathematical Education in Science & Technology》2013,44(8):1143-1159
This empirical study explores the roles that Emotional Intelligence (EI) and Emotional Self-Efficacy (ESE) play in undergraduates’ mathematical literacy, and the influence of EI and ESE on students’ attitudes towards and beliefs about mathematics. A convenience sample of 93 female and 82 male first-year undergraduates completed a test of mathematical literacy, followed by an online survey designed to measure the students’ EI, ESE and factors associated with mathematical literacy. Analysis of the data revealed significant gender differences. Males attained a higher mean test score than females and out-performed the females on most of the individual questions and the associated mathematical tasks. Overall, males expressed greater confidence in their mathematical skills, although both males’ and females’ confidence outweighed their actual mathematical proficiency. Correlation analyses revealed that males and females attaining higher mathematical literacy test scores were more confident and persistent, exhibited lower levels of mathematics anxiety and possessed higher mathematics qualifications. Correlation analyses also revealed that in male students, aspects of ESE were associated with beliefs concerning the learning of mathematics (i.e. that intelligence is malleable and that persistence can facilitate success), but not with confidence or actual performance. Both EI and ESE play a greater role with regard to test performance and attitudes/beliefs regarding mathematics amongst female undergraduates; higher EI and ESE scores were associated with higher test scores, while females exhibiting higher levels of ESE were also more confident and less anxious about mathematics, believed intelligence to be malleable, were more persistent and were learning goal oriented. Moderated regression analyses confirmed mathematics anxiety as a negative predictor of test performance in males and females, but also revealed that in females EI and ESE moderate the effects of anxiety on test performance, with the relationship between anxiety and test performance linked more to emotional management (EI) than to ESE. 相似文献
125.
We have performed electrical resistivity and specific heat measurements on bulk Eu1.1Mo6S8 together with low-temperature X-ray powder diffractometry. These investigations revealed a structural phase transition (occuring at 109 K) from the room-temperature rhombohedral structure to a low-temperature triclinic distorted structure in which the compound exhibits a non-metallic behavior. 相似文献
126.
Yvon Bossard 《Annali di Matematica Pura ed Applicata》1975,102(1):1-36
Summary New techniques are developed, based on the consideration of the projective bundle associated with a direct sum of two vector
bundles, to give a simpler solution of the problem of blowing up Chern classes which was previously solved by Porteous[12] using the Grothendieck Riemann-Roch theorem.
Dedicated to ProfessorBeniamino Segre
Entrata in Redazione il 2 aprile 1973. 相似文献
127.
128.
129.
Epidermal reconstructs: a new tool to study topical and systemic photoprotective molecules 总被引:2,自引:0,他引:2
Cario-André M Briganti S Picardo M Nikaido O Gall Y Ginestar J Taïeb A 《Journal of photochemistry and photobiology. B, Biology》2002,68(2-3):79-87
In this study, we compared the effects of sunscreens and antioxidants on reconstructed epidermis made with or without melanocytes 24 h after UVB, UVA or UVA+B irradiation. For this purpose, we studied sunburn cells and cyclobutane pyrimidine dimer formation, protein and lipid oxidation, catalase and superoxide dismutase activities and vitamin E levels. Topical sunscreens protected against direct cell death and thymine dimer formation whereas their protective effect against protein and lipid oxidation and antioxidant depletion was less marked partly due to the difficulty of spreading the cream. Antioxidant molecules protected against direct cell death and protein oxidation but not against thymine dimer formation. Since topical sunscreens and systemic antioxidant protected the skin differently, we speculate that their association might protect more efficiently against UV-induced damage. This model is relevant to study systemic molecules but is less practical, due to the technical limitations of studying topical molecules. 相似文献
130.
J.-M. Joubert R. ?ernýM. Latroche E. LeroyL. Guénée A. Percheron-GuéganK. Yvon 《Journal of solid state chemistry》2002,166(1):1-6
LaNi5 is a very important intermetallic compound for hydrogen storage applications. Its homogeneity range at 1200°C has been investigated by single-crystal X-ray diffraction, electron probe microanalysis, and mass density measurements. At the nickel-rich end the hexagonal structure (CaCu5 type) extends to the composition LaNi5.45. The excess of nickel is accommodated by random substitutions of lanthanum atoms by nickel dumbbells and by displacements of nickel atoms which are presumably correlated with the La atom substitutions. Interatomic distances suggest that the Ni atom displacements occur in directions toward vacant La atom sites, i.e., toward the center of Ni dumbbells. At the nickel-poor end the structure extends to the composition LaNi4.88. The excess of lanthanum is presumably accommodated by the simultaneous occurrence of lanthanum atoms and vacancies on nickel atom sites. Both models are consistent with mass density and electron probe microanalysis measurements. Hydrogenation thermodynamic properties have been measured as a function of composition. 相似文献