全文获取类型
收费全文 | 1172篇 |
免费 | 45篇 |
国内免费 | 12篇 |
专业分类
化学 | 760篇 |
晶体学 | 2篇 |
力学 | 59篇 |
数学 | 233篇 |
物理学 | 175篇 |
出版年
2024年 | 4篇 |
2023年 | 14篇 |
2022年 | 13篇 |
2021年 | 19篇 |
2020年 | 27篇 |
2019年 | 19篇 |
2018年 | 20篇 |
2017年 | 18篇 |
2016年 | 44篇 |
2015年 | 46篇 |
2014年 | 31篇 |
2013年 | 54篇 |
2012年 | 77篇 |
2011年 | 90篇 |
2010年 | 54篇 |
2009年 | 49篇 |
2008年 | 64篇 |
2007年 | 72篇 |
2006年 | 70篇 |
2005年 | 72篇 |
2004年 | 74篇 |
2003年 | 48篇 |
2002年 | 31篇 |
2001年 | 17篇 |
2000年 | 13篇 |
1999年 | 12篇 |
1998年 | 10篇 |
1997年 | 16篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 10篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1909年 | 4篇 |
1908年 | 3篇 |
排序方式: 共有1229条查询结果,搜索用时 15 毫秒
51.
Rondahl Stina Holmgren Pointurier Fabien Ahlinder Linnea Ramebäck Henrik Marie Olivier Ravat Brice Delaunay François Young Emma Blagojevic Ned Hester James R. Thorogood Gordon Nelwamondo Aubrey N. Ntsoane Tshepo P. Roberts Sarah K. Holliday Kiel S. 《Journal of Radioanalytical and Nuclear Chemistry》2018,315(2):395-408
Journal of Radioanalytical and Nuclear Chemistry - This work presents the results for identification of chemical phases obtained by several laboratories as a part of an international nuclear... 相似文献
52.
Nelwamondo Aubrey N. Colletti Lisa P. Lindvall Rachel E. Vesterlund Anna Xu Ning Tan Angela Hiong Jun Eppich Gary R. Genetti Victoria D. Kokwane Banyana L. Lagerkvist Petra Pong Boon Kin Ramebäck Henrik Tandon Lav Rasmussen Gert Varga Zsolt Wallenius Maria 《Journal of Radioanalytical and Nuclear Chemistry》2018,315(2):379-394
Journal of Radioanalytical and Nuclear Chemistry - An international group of laboratories participating in CMX-4 subjected three samples to comparative nuclear forensic analysis using uranium assay... 相似文献
53.
De La Rosa Nathaly Kristiansson Per Nilsson E. J. Charlotta Ros Linus Pallon Jan Skogby Henrik 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):253-259
Journal of Radioanalytical and Nuclear Chemistry - Proton-induced reaction (p,α) is one type of nuclear reaction analysis (NRA) suitable especially for light element quantification.... 相似文献
54.
Mikkel Jørgensen Prof. Henrik Grönbeck 《Angewandte Chemie (International ed. in English)》2018,57(18):5086-5089
Heterogeneous catalysts are often designed as metal nanoparticles supported on oxide surfaces. Here, the relation between particle morphology and reaction kinetics is investigated by scaling relation kinetic Monte Carlo simulations using CO oxidation over Pt nanoparticles as a model reaction. We find that different particle morphologies result in vastly different catalytic activities. The activity is strongly affected by kinetic couplings between sites, and a wide site distribution generally enhances the activity. The present study highlights the role of site‐assemblies as a concept that, in addition to isolated active sites, can be used to understand catalytic reactions over nanoparticles. 相似文献
55.
Henrik Birkedal Dieter Schwarzenbach Philip Pattison 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):975-977
The crystal structure of the neuroactive artificial dipeptide N‐benzyloxycarbonylprolyl‐d ‐leucine, C19H26N2O5, was solved using synchrotron radiation data collected on a very small crystal (20 × 20 × 380 μm). The molecules form hydrogen‐bonded 21 helices. The acid carbonyl group does not participate in strong hydrogen bonds. This is interpreted as a consequence of close‐packing requirements. 相似文献
56.
Low-frequency Raman spectra of catechol (1,2-dihydroxybenzene) and catechol-d2 have been measured at 130 K. The stretching mode of the intermolecular hydrogen bond, νσ, has been assigned at 187 and 184 cm?1, respectively. A short discussion of this assignment and its implications with respect to the previously reported guaiacol (2-methoxyphenol) spectra is presented. 相似文献
57.
58.
Antoine Henrot Henrik Shahgholian 《Transactions of the American Mathematical Society》2002,354(6):2399-2416
Our objective, here, is to generalize our earlier results on the existence of classical convex solution to a free boundary problem with a Bernoulli-type boundary gradient condition and with the -Laplacian as the governing operator. The main theorems of this paper assert that the exterior and the interior free boundary problem with a Bernoulli law, i.e. with a prescribed pressure on the ``free' streamline of the flow, have convex solutions provided the initial domains are convex. The continuous function is subject to certain convexity properties. In our earlier results we have considered the case of constant . In the lines of the proof of the main results we also prove the semi-continuity (up to the boundary) of the gradient of the -capacitary potentials in convex rings, with boundaries.
59.
A simple desalting procedure for the coupling of a polymer microchip injector to mass spectrometry is proposed. The overall process is based on the adsorption of proteins on a poly(vinylidene difluoride) (PVDF) membrane, which are then directly eluted in the spraying solution. This microchip-based approach has been successfully applied to small drugs, peptides and proteins originally diluted in phosphate-buffered saline (PBS). Moreover, when eluting the retained proteins in small volumes, a preconcentration is obtained. The combination of single-use, mass-produceable, low-sample-consumption, easy-to-automate, miniaturized polymer injectors with easy-to-handle solution-exchange membranes makes this system particularly amenable to screening applications. 相似文献
60.
Bertram HC Rasmussen M Busk H Oksbjerg N Karlsson AH Andersen HJ 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2002,157(2):267-276
This study investigates the effects of developmental stage and muscle type on the mobility and distribution of water within skeletal muscles, using low-field (1)H-NMR transverse relaxation measurements in vitro on four different porcine muscles (M. longissimus dorsi, M. semitendinosus, M. biceps femoris, M. vastus intermedius) from a total of 48 pigs slaughtered at various weight classes between 25 kg and 150 kg. Principal component analysis (PCA) revealed effects of both slaughter weight and muscle type on the transverse relaxation decay. Independent of developmental stage and muscle type, distributed exponential analysis of the NMR T(2) relaxation data imparted the existence of three distinct water populations, T(2b), T(21), and T(22), with relaxation times of approximately 1-10, 45-120, and 200-500 ms, respectively. The most profound change during muscle growth was a shift toward faster relaxation in the intermediate time constant, T(21). It decreased by approx. 24% in all four muscle types during the period from 25 to 150 kg live weight. Determination of dry matter, fat, and protein content in the muscles showed that the changes in relaxation time of the intermediate time constant, T(21), during growth should be ascribed mainly to a change in protein content, as the protein content explained 77% of the variation in the T(21) time constant. Partial least squares (PLS) regression revealed validated correlations in the region of 0.58 to 0.77 between NMR transverse relaxation data and muscle development for all the four muscle types, which indicates that NMR relaxation measurements may be used in the prediction of muscle developmental stage. 相似文献