全文获取类型
收费全文 | 215篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
化学 | 85篇 |
晶体学 | 1篇 |
力学 | 8篇 |
数学 | 44篇 |
物理学 | 81篇 |
出版年
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2014年 | 9篇 |
2013年 | 9篇 |
2012年 | 8篇 |
2011年 | 6篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 13篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1965年 | 1篇 |
1963年 | 1篇 |
1937年 | 1篇 |
1887年 | 1篇 |
1886年 | 1篇 |
排序方式: 共有219条查询结果,搜索用时 31 毫秒
21.
The structure of N-unsubstituted 1,2,4-Benzothiadiazine-1,1-dioxides has been investigated by means of NMR spectroscopy. 13C NMR spectra obtained in DMSO-d6, solution show the actual tautomeric form to be the 4H tautomer. 相似文献
22.
Jørgen Jakobsen 《Applied Acoustics》1980,13(6):457-469
A data logging system used for long-term noise measurements is described. The system's ability to measure impulsive noise correctly is analysed and compared with that of other systems. It is concluded that the systems considered in the investigation are able to measure impulsve noise with an error not exceeding 1 dB, provided the crest factor of the noise is less than 30 dB. 相似文献
23.
Espen Robstad Jakobsen 《Proceedings of the American Mathematical Society》2004,132(11):3203-3213
In this paper we provide and analyze a nonlinear degenerate parabolic equation in one space dimension with the following smoothing property: If the initial data is only uniformly continuous, at positive times, the solution has bounded second derivatives (it belongs to ). We call this surprising phenomenon a regularizing effect. So far, such phenomena have only been observed in uniformly parabolic equations.
24.
Bearden IG Beavis D Besliu C Blyakhman Y Budick B Bøggild H Chasman C Christensen CH Christiansen P Cibor J Debbe R Enger E Gaardhøje JJ Germinario M Hagel K Hansen O Holm A Holme AK Ito H Jakobsen E Jipa A Jundt F Jørdre JI Jørgensen CE Karabowicz R Keutgen T Kim EJ Kozik T Larsen TM Lee JH Lee YK Løvhøiden G Majka Z Makeev A McBreen B Mikelsen M Murray M Natowitz J Nielsen BS Norris J Olchanski K Olness J Ouerdane D Płaneta R Rami F Ristea C Röhrich D Samset BH Sandberg D Sanders SJ 《Physical review letters》2003,90(10):102301
We present ratios of the numbers of charged antihadrons to hadrons (pions, kaons, and protons) in Au+Au collisions at sqrt[s(NN)]=200 GeV as a function of rapidity in the range y=0-3. While the ratios at midrapidity are approaching unity, the K(-)/K(+) and p;/p ratios decrease significantly at forward rapidities. An interpretation of the results within the statistical model indicates a reduction of the baryon chemical potential from mu(B) approximately 130 MeV at y=3 to mu(B) approximately 25 MeV at y=0. 相似文献
25.
The stereospecific oxidation of hydrazine into cis-diimide and the catalytic disproportionation of hydrogen peroxide effected by selenoxides are suggested to involve a dissociative cycloelimination from an intermediary selenurane. 相似文献
26.
We obtain estimates on the continuous dependence on the coefficient for second-order non-linear degenerate Neumann type boundary value problems. Our results extend previous work of Cockburn et al., Jakobsen and Karlsen, and Gripenberg to problems with more general boundary conditions and domains. A new feature here is that we account for the dependence on the boundary conditions. As one application of our continuous dependence results, we derive for the first time the rate of convergence for the vanishing viscosity method for such problems. We also derive new explicit continuous dependence on the coefficients results for problems involving Bellman-Isaacs equations and certain quasilinear equation. 相似文献
27.
Samit Mandal J Gerl H Geissel K Hauschild M Hellström Z Janas I Kojouharov Y Kopatch RC Lemmon P Mayet Z Podolyak PH Regan H Schaffner C Schlegel J Simpson HJ Wollersheim 《Pramana》2001,57(1):161-164
Feasibility of gamma-ray spectroscopy at relativistic energies with exotic heavy-ions and new generation of germanium detectors
(segmented Clover) is discussed. An experiment with such detector array and radioactive is discussed. 相似文献
28.
29.
HJ. Mellin 《Acta Mathematica》1886,8(1):37-80
Ohne Zusammenfassung
Vergl. meine Abhandlung:Om en ny klass af transcendenta functioner, hvilka ?ro n?ra besl?gtade med gammafunktionen, Acta soc. scient. Fennic?, Tom. XIV, XV; 1885, 1886. 相似文献
30.
Guarato F Jakobsen L Vanderelst D Surlykke A Hallam J 《The Journal of the Acoustical Society of America》2011,129(2):1046-1058
Taking into account directivity of real sound sources makes it possible to try solving an interesting and biologically relevant problem: estimating the orientation in three-dimensional space of a directional sound source. The source, of known directivity, produces a broadband signal (in the ultrasonic range, in this application) that is recorded by microphones whose position with respect to source is known. An analytical method to process the recorded signals and estimate source orientation is developed in this paper. Experiments testing method performance in estimating source orientation were performed both in a laboratory environment with a Polaroid transducer as source and in a flight room with a Myotis daubentonii bat. In the first case, results showed the estimation method to be accurate and pointed out its limitations. The latter case is significant as an example biological application of the method for extracting behavioral features from bats; results are compared with alternative calculations based on microphone root-mean-square (rms)-pressure values. 相似文献