全文获取类型
收费全文 | 585篇 |
免费 | 22篇 |
国内免费 | 23篇 |
专业分类
化学 | 346篇 |
晶体学 | 10篇 |
力学 | 9篇 |
数学 | 72篇 |
物理学 | 193篇 |
出版年
2022年 | 9篇 |
2021年 | 8篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 19篇 |
2012年 | 25篇 |
2011年 | 32篇 |
2010年 | 11篇 |
2009年 | 19篇 |
2008年 | 24篇 |
2007年 | 28篇 |
2006年 | 23篇 |
2005年 | 12篇 |
2004年 | 29篇 |
2003年 | 20篇 |
2002年 | 20篇 |
2001年 | 15篇 |
2000年 | 19篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 11篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 19篇 |
1993年 | 20篇 |
1992年 | 22篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 14篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1909年 | 2篇 |
排序方式: 共有630条查询结果,搜索用时 15 毫秒
1.
A. Ray R. Sriravindrarajah J.-P. Guerbois P. S. Thomas S. Border H. N. Ray J. Haggman P. Joyce 《Journal of Thermal Analysis and Calorimetry》2007,88(1):279-283
The use of supplementary cementitious materials (SCM) is a well established practice worldwide in the manufacture of Portland cement (PC)-based construction materials. While utilisation of industrial by-products has been successful, the potential of mining wastes is yet to receive adequate attention in the context of construction materials. In an expanded form perlite, which is a naturally occurring, hydrated volcanic siliceous glass, is an ideal material as a lightweight aggregate for use in a wide range of construction materials including concrete. The mining and processing of the grades of perlite required for the production of lightweight aggregate results in the creation of a fine grained waste which currently has no economic value. This paper reports preliminary data on the utilisation of waste perlite fines as a SCM in calcium silicate-based construction material and discusses the potential of this mining waste to reduce the environmental impact of the production of conventional cement-based construction materials. 相似文献
2.
3.
4.
Kochocki JA Allison WW Alner GJ Ambats I Ayres DS Balka LJ Barr GD Barrett WL Benjamin D Border P Brooks CB Cobb JH Cockerill DJ Coover K Courant H Dahlin B DasGupta U Dawson JW Edwards VW Fields TH Kirby-Gallagher LM Garcia-Garcia C Giles RH Goodman MC Heller K Heppelman S Hill N Hoftiezer JH Jankowski DJ Johns K Joyce T Kafka T Litchfield PJ Lopez FV Lowe M Mann WA Marshak ML May EN McMaster L Milburn RH Miller W Napier A Oliver WP Pearce GF Perkins DH Peterson EA Price LE Roback D Rosen DB 《Physical review D: Particles and fields》1990,42(9):2967-2973
5.
Mathiazhagan C Molzon WR Cousins RD Konigsberg J Kubic J Melese P Rubin P Slater WE Wagner D Hart GW Kinnison WW Lee DM McKee RJ Milner EC Sanders GH Ziock HJ Arisaka K Knibbe P Urheim J Axelrod S Biery KA Irwin GM Lang K Margulies J Ouimette DA Ritchie JL Trang QH Wojcicki SG Auerbach LB Buchholz P Highland VL McFarlane WK Sivertz M Chapman MD Eckhause M Ginkel JF Hancock AD Joyce D Kane JR Kenney CJ Vulcan WF Welsh RE Whyley RJ Winter RG 《Physical review letters》1989,63(20):2181-2184
6.
R. L. S. Devine C. T. Foxon B. A. Joyce J. B. Clegg J. P. Gowers 《Applied Physics A: Materials Science & Processing》1987,44(2):195-200
Beryllium diffusion during MBE growth of (Al, Ga)As layers, (Al, Ga)As/GaAs heterojunctions and GaAs/AlAs superlattices has been studied by electrochemical C-V and secondary ion mass spectrometry (SIMS) concentration profiling, in conjunction with transmission electron microscopy. Diffusion times were comparatively short since they were limited to part of the growth sequence, so non-equilibrium effects had a significant influence. The results are consistent with an interstitial-substitutional mechanism in which lattice site incorporation becomes more difficult with increasing band gap enthalpy. Incorporation involves a kick-out reaction which leads to the observed disordering of the superlattices. 相似文献
7.
A simple and efficient preparation of gramicidin S and its analogues is described. It involves solid-phase peptide synthesis and on-resin macrolactamization without side chain protection, affording cyclic products in high yield and high purity. The high specificity of the cyclization reaction was shown to originate in the formation of a pre-organized conformation of the linear biosynthetic precursor of gramicidin S. This facile method will provide convenient access to the analogues of the natural product for functional optimization to counter microbial resistance. 相似文献
8.
Gelebe AC Kaye PT Klein R Sewry JD Soper AG 《Magnetic resonance in chemistry : MRC》2005,43(11):952-955
The influence of substituents and structure on the 13C NMR spectra of four series of benzoxathiepine derivatives has been investigated. Signal assignments in the 13C NMR spectra have been facilitated by the use of several predictive methods, permitting comparison of their relative efficacy. 相似文献
9.
10.
Arisaka K Auerbach LB Axelrod S Belz J Biery KA Buchholz P Chapman MD Cousins RD Diwan MV Eckhause M Ginkel JF Guss C Hancock AD Heinson AP Highland VL Hoffmann GW Horvath J Irwin GM Joyce D Kaarsberg T Kane JR Kenney CJ Kettell SH Kinnison WW Knibbe P Konigsberg J Kuang Y Lang K Lee DM Margulies J Mathiazhagan C McFarlane WK McKee RJ Melese P Milner EC Molzon WR Ouimette DA Riley PJ Ritchie JL Rubin P Sanders GH Schwartz AJ Sivertz M Slater WE Urheim J Vulcan WF Wagner DL Welsh RE Whyley RJ 《Physical review letters》1993,71(24):3910-3913