全文获取类型
收费全文 | 2465篇 |
免费 | 74篇 |
国内免费 | 10篇 |
专业分类
化学 | 1771篇 |
晶体学 | 26篇 |
力学 | 30篇 |
数学 | 106篇 |
物理学 | 616篇 |
出版年
2023年 | 11篇 |
2021年 | 20篇 |
2020年 | 19篇 |
2019年 | 31篇 |
2018年 | 26篇 |
2017年 | 9篇 |
2016年 | 44篇 |
2015年 | 45篇 |
2014年 | 71篇 |
2013年 | 103篇 |
2012年 | 144篇 |
2011年 | 159篇 |
2010年 | 78篇 |
2009年 | 102篇 |
2008年 | 155篇 |
2007年 | 173篇 |
2006年 | 131篇 |
2005年 | 131篇 |
2004年 | 99篇 |
2003年 | 112篇 |
2002年 | 116篇 |
2001年 | 68篇 |
2000年 | 46篇 |
1999年 | 24篇 |
1998年 | 21篇 |
1997年 | 28篇 |
1996年 | 31篇 |
1995年 | 19篇 |
1994年 | 19篇 |
1993年 | 34篇 |
1992年 | 31篇 |
1991年 | 25篇 |
1990年 | 33篇 |
1989年 | 23篇 |
1988年 | 30篇 |
1987年 | 33篇 |
1986年 | 36篇 |
1985年 | 35篇 |
1984年 | 24篇 |
1983年 | 14篇 |
1982年 | 15篇 |
1981年 | 14篇 |
1980年 | 13篇 |
1979年 | 21篇 |
1978年 | 15篇 |
1977年 | 17篇 |
1976年 | 14篇 |
1975年 | 20篇 |
1974年 | 22篇 |
1973年 | 13篇 |
排序方式: 共有2549条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
M. Fukushima H. Tamate N. Fujii Y. Nakano 《Journal of Radioanalytical and Nuclear Chemistry》2003,257(1):105-108
In this work, we determined the levels of trace metals in protein fractions isolated from rock oysters by neutron activation analysis (NAA) and particle induced X-ray emission (PIXE). Proteins were extracted from mantles and hepatopancreases of rock oysters and fractionated by size-exclusion high performance liquid chromatography (HPLC). The protein fractions from mantles and hepatopancreases are found to be abundant in Fe, Cu, Zn, Mn, Pb, and Ag. HPLC profiles of Fe, Cu, Zn, and Ag indicate that those elements are bound to proteins extracted from mantles and hepatopancreases. 相似文献
15.
Shigeru Katayama Mika Horiike Kazuyuki Hirao Naoto Tsutsumi 《Journal of Polymer Science.Polymer Physics》2002,40(24):2800-2806
We investigated the structures induced by an irradiation of a near‐infrared (NIR) femtosecond laser pulse in dye‐doped polymeric materials {poly(methyl methacrylate) (PMMA), thermoplastic epoxy resin (Epoxy), and a block copolymer of methyl methacrylate and ethyl acrylate‐butyl acrylate [p(MMA/EA‐BA) block copolymer]}. Dyes used were classified into two types—type 1 with absorption at 400 nm and type 2 with no absorption at 400 nm. The 400‐nm wavelength corresponds to the two‐photon absorption region by the irradiated NIR laser pulse at 800 nm. Type 1 dye‐doped PMMA and p(MMA/EA‐BA) block copolymer showed a peculiar dye additive effect for the structures induced by the line irradiation of a NIR femtosecond laser pulse. On the contrary, dye‐doped Epoxy did not exhibit a dye additive effect. The different results among PMMA, p(MMA/EA‐BA) block copolymer, and Epoxy matrix polymers are supposed to be related to the difference of electron‐acceptor properties. The mechanism of this type 1 dye‐additive‐effect phenomenon for PMMA and p(MMA/EA‐BA) block copolymer is discussed on the basis of two‐photon absorption of type 1 dye at 400 nm by the irradiation of a femtosecond laser pulse with 800 nm wavelength and the dissipation of the absorbed energy to the polymer matrix among various transition processes. Dyes with a low‐fluorescence quantum yield favored the formation of thicker grating structures. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2800–2806, 2002 相似文献
16.
Tomoji Kumano Yoshifumi Ohata Norikazu Fujii Yoshiyuki Ushigami Tetsuro Takeshita 《Journal of magnetism and magnetic materials》2006
All kinds of high-permeability GO are manufactured using AlN as the main inhibitor. From a purely metallurgical viewpoint, three types of inhibitor preparation for high-permeability GO have been shown. They include a complete solution without nitriding, a complete precipitation with nitriding and a partial precipitation with nitriding. In this study, another possibility, i.e., a complete solution method with nitriding, was investigated to avoid the extra high-temperature slab reheating and to examine the effect of nitriding on GO bearing Al. This method can also provide the sharp Goss texture, and nitriding is shown to be very useful for changing the inhibitor intensity, depending on the primary grain size. 相似文献
17.
N Fujii T Watanabe A Otaka K Bessho I Yamamoto T Noda H Yajima 《Chemical & pharmaceutical bulletin》1987,35(12):4769-4776
18.
Stuart D Breedon RE Kim GN Ko W Lander RL Maeshima K Malchow RL Smith JR Imlay R Kirk P Lim J McNeil RR Metcalf W Myung SS Cheng CP Gu P Li J Li YK Ye MH Zhu YC Abashian A Gotow K Hu KP Low EH Mattson ME Piilonen L Sterner KL Lusin S Rosenfeld C Wang AT Wilson S Frautschi M Kagan H Kass R Trahern CG Abe K Fujii Y Higashi Y Kim SK Kurihara Y Maki A Nozaki T Omori T Sagawa H Sakai Y Sugimoto Y Takaiwa Y Terada S Walker R Kajino F Perticone D Poling R Thomas T Ishi Y Miyano K Miyata H Sasaki T 《Physical review letters》1990,64(9):983-986
19.
20.