全文获取类型
收费全文 | 455篇 |
免费 | 25篇 |
国内免费 | 4篇 |
专业分类
化学 | 371篇 |
晶体学 | 2篇 |
力学 | 3篇 |
数学 | 49篇 |
物理学 | 59篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 25篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 31篇 |
2012年 | 38篇 |
2011年 | 35篇 |
2010年 | 22篇 |
2009年 | 14篇 |
2008年 | 31篇 |
2007年 | 15篇 |
2006年 | 27篇 |
2005年 | 23篇 |
2004年 | 18篇 |
2003年 | 18篇 |
2002年 | 15篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有484条查询结果,搜索用时 0 毫秒
431.
432.
Hirotaka Okamoto Tadashi Inoue Kunihiro Osaki 《Journal of Polymer Science.Polymer Physics》1995,33(9):1409-1416
The complex Young's modulus, E*(ω), and the complex strain-optical coefficient, O*(ω), were measured for polyisobutylene (PIB) over a wide temperature range near and above its glass transition temperature. The master curves could be constructed well for each function with the method of reduced variables. The shift factor, aT, for E*(ω) is the same as that for O*(ω). The ratio of the imaginary parts of O*(ω) and E*(ω), O″(ω)/E″(ω), takes an extremum, which has never been observed for other polymers. The relation between O*(ω) and E*(ω) cannot be described by a modified stress-optical rule (MSOR) which has been found valid for various polymers. The basic concept of the MSOR. i.e., the chain orientation and the orientation of flat monomer units in the stretch direction, is not sufficient to describe the behavior of PIB and another origin of stress, presumably due to the fluctuation of local stress, should be included. This term does not contribute to the birefringence. The main maximum of tan δ is ascribed to the relaxation of the chain orientation in contrast with many other polymers, such as polyisoprene and polycarbonate, for which the maximum of tan δ is ascribed to the rotational relaxation of monomer units. © 1995 John Wiley & Sons, Inc. 相似文献
433.
434.
Keishi Kanada Akira Oosawa Takao Suzuki Hirotaka Manaka 《Journal of Physics and Chemistry of Solids》2007,68(11):2191-2194
The ground state of the solid solution of the two spin gap systems (CH3)2CHNH3CuCl3 and (CH3)2CHNH3CuBr3 has been investigated by 1H NMR. The existence of a magnetic ordering in the sample with the Cl-content x=0.85 was clearly demonstrated by a drastic splitting in a resonance line at low temperatures below TN=13.5 K. The observed NMR spectra in the ordered state was qualitatively consistent with the simple antiferromagnetic state. 相似文献
435.
We construct an ab initio generic structure for a predimension function with a positive rational coefficient less than or equal to 1 which is unsaturated and has a superstable non-ω-stable theory. 相似文献
436.
The link of an affine real algebraic variety at a point is defined to be the intersection of the variety with a small sphere centred at the point. The Euler characteristic of the link leads to local topological characterisation of real algebraic varieties in law dimensions. We prove in the paper that not only the Euler characteristic, but also the stronger virtual Poincaré polynomial is well-defined for the link at a point of an affine algebraic variety. 相似文献
437.
Optical Review - This study aimed to examine the effect of the cut ratio on contrast sensitivity by modifying the cut rate of the wavelength-selective cut lens at approximately 585 nm.... 相似文献
438.
Eita Tochigi Hirofumi Matsuhata Hirotaka Yamaguchi Takashi Sekiguchi Hajime Okumura Yuichi Ikuhara 《哲学杂志》2013,93(9):657-670
AbstractWe investigated two types of V-shaped extended defects on the basal plane in epitaxial 4H-SiC by synchrotron X-ray topography, photoluminescence imaging/spectroscopy and transmission electron microscopy (TEM). One is the (2, 5) stacking fault (in Zhdanov notation) bounded by two partial dislocations with the Burgers vector b ± 1/4[0?0?0?1]; the other is the (2, 3, 3, 5) stacking fault bounded by partial dislocations with b = ±1/4[0?0?0?1]. The core of the partial dislocations associated with the (2, 3, 3, 5) fault has an out-of-plane component (Frank component) and three in-plane components (Shockley components); the three Shockley components are cancelled out in total. The electronic structures of the (2, 5) and (2, 3, 3, 5) stacking faults were further examined by photoluminescence spectroscopy and first-principles calculations. It is suggested that the (2, 5) and (2, 3, 3, 5) stacking faults both have an interband state at a similar energy level, although they differ structurally. 相似文献
439.
440.