全文获取类型
收费全文 | 483篇 |
免费 | 21篇 |
专业分类
化学 | 397篇 |
晶体学 | 8篇 |
力学 | 8篇 |
数学 | 25篇 |
物理学 | 66篇 |
出版年
2022年 | 6篇 |
2021年 | 4篇 |
2020年 | 11篇 |
2019年 | 14篇 |
2018年 | 3篇 |
2016年 | 8篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 13篇 |
2012年 | 30篇 |
2011年 | 27篇 |
2010年 | 4篇 |
2009年 | 15篇 |
2008年 | 26篇 |
2007年 | 31篇 |
2006年 | 28篇 |
2005年 | 31篇 |
2004年 | 31篇 |
2003年 | 22篇 |
2002年 | 14篇 |
2001年 | 17篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1984年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1968年 | 3篇 |
1967年 | 7篇 |
1966年 | 2篇 |
排序方式: 共有504条查询结果,搜索用时 31 毫秒
501.
Yoshinori Kamiya Yasutoshi Naito Keishin Mizoguchi Katsuhiko Terada Johann Moreau 《Journal of Polymer Science.Polymer Physics》1997,35(7):1049-1053
The Flory–Huggins interaction parameters χ for 23 gases (He, Ne, Ar, Kr, Xe, H2, N2, O2, N2O, CO2, CH4, C2H4, C2H6, C3H6, C3H8, 1,3-C4H6, four C4H8's, n-C4H10, iso-C4H10, and n-C5H12) in five rubbery polymers (1,2-polybutadiene (PB), poly(ethylene-co-vinyl acetate)) (EVAc), polyethylene (PE), polypropylene (PP), and poly(dimethyl siloxane) (PDMS) were determined from either literature data on Henry's law coefficient and partial molar volume or those on sorptive dilation for each polymer/gas system. Values of χ for the gases increased in the order of PDMS < PP ≡ PB < EVAc ≡ PE. Among the gases except He and H2 whose χ values are not reliable, Ne and Xe have respectively the highest and the lowest values of χ for the polyolefins. The χ values of the hydrocarbons were compared together with previously reported χ values of n-alkanes C3-C10. The dependencies of χ upon concentration and temperature were discussed on the basis of the literature data. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 1049–1053, 1997 相似文献
502.
Solubilization of hydrophilic saccharide chains into organic solvents has been attempted by incorporating saccharide-substituted styrene unit into polystyrene main chain. Lactose-, maltopentaose, and amylose-substituted styrene monomers were copolymerized with styrene. Resulting chloroform-soluble copolymers were characterized, and structural formation was investigated. Copolymers of lactose-substituted styrene and maltopentaose-substituted styrene with styrene were dissolved into chloroform. The chloroform-soluble polymers contained about 12 disaccharide lactose chains or 1.7 maltopentaose chains as the pendant groups in one polystyrene molecule. Chloroform-insoluble methyl orange was dissolved into chloroform with the help of chloroform-soluble polystyrene having some saccharide chains. On the other hand, when an amylose-substituted styrene unit was inserted in a polystyrene chain, the resulting polymer became insoluble into chloroform. Amylose polysaccharide of DPn = ∼24 was not dissolved into chloroform by this method. 相似文献
503.
Natsuo Nagamura Prof. Hisahiro Sasabe Hiroki Sato Nozomi Ito Shoki Abe Dr. Yoshihito Sukegawa Prof. Daisuke Yokoyama Prof. Hironori Kaji Prof. Junji Kido 《Chemistry (Weinheim an der Bergstrasse, Germany)》2023,29(1):e202202636
Using a tailored high triplet energy hole transport layer (HTL) is a suitable way to improve the efficiency and extend the lifetime of organic light-emitting devices (OLEDs), which can use all molecular excitons of singlets and triplets. In this study, dibenzofuran (DBF)-end-capped and spirobifluorene (SBF) core-based HTLs referred as TDBFSBF1 and TDBFSBF2 were effectively developed. TDBFSBF1 exhibited a high glass transition temperature of 178 °C and triplet energy of 2.5 eV. Moreover, a high external quantum efficiency of 22.0 %, long operational lifetime at 50 % of the initial luminance of 89,000 h, and low driving voltage at 1000 cd m−2 of 2.95 V were achieved in green phosphorescent OLEDs using TDBFSBF1 . Further, a high-hole mobility μh value of 1.9×10−3 cm2 V−1 s−1 was recorded in TDBFSBF2 . A multiscale simulation successfully reproduced the experimental μh values and indicated that the reorganization energy was the primary factor in determining the mobility differences among these SBF core based HTLs. 相似文献
504.
A. Okada K. Mitsui T. Kitamura Y. Ohashi Y. Muraki T. Suda I. Nakamura Y. Kawashima S. Matsuno F. Kajino T. Aoki S. Higashi S. Ozaki T. Takahashi K. Honda K. Kobayakawa H. Inazawa Y. Minorikawa M. Shibata H. Shibata Y. Kamiya Y. Teramoto 《Fortschritte der Physik》1984,32(4):135-173
Hadronic cascade showers originating from inelastic interactions of cosmic ray muons with iron nuclei have been observed in a calorimeter located between two magnetic spectrometers. The separation of those events from the electromagnetic showers has been successfully done in the ranges of the transferred energy v ≳ 50 GeV and its ratio to muon energy v/E ≳ 0,1, by utilizing the difference of their longitudinal cascade developments. The comparison of the obtained μ-Fe cross section with available μ-, e- and σ-proton data as well as μ-, e- and σ-nucleus data indicates that;
- 1 At v ˜ 100 GeV, the virtual photon cross section on iron nucleus is almost the same as the real photon one, at least Q2 ≳ 0.1 GeV2/c2, and is about 70% of the cross section on proton times the atomic mass number of iron, i.e. the shadowing effect is clearly seen.
- 2 Up to TeV region, this virtual photon cross section on iron does not increase significantly. contrary to the tendency of the real photon cross section on proton around 100 GeV. This suggests most likely that the shadowing still increases with energy at such high energies.