全文获取类型
收费全文 | 201篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
化学 | 92篇 |
晶体学 | 1篇 |
数学 | 32篇 |
物理学 | 83篇 |
出版年
2018年 | 1篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 7篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1985年 | 13篇 |
1984年 | 8篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1974年 | 20篇 |
1973年 | 7篇 |
排序方式: 共有208条查询结果,搜索用时 421 毫秒
21.
A theoretical investigation has been carried out of surface polaritons associated with surface magnetoplasmons coupled to surface optical phonons in polar semiconductors. The coupled mode frequencies are calculated for several orientations of the magnetic field relative to the surface and the direction of propagation in the large wave vector (unretarded) limit. Dispersion curves are calculated for the configuration in which the magnetic field is parallel to the surface and is perpendicular to the wave vector. Experimental possibilities for observing the interaction effects are discussed. 相似文献
22.
G DAgostini G Auriemma J.P de Brion A Caillet J.B Cheze J Derré G Marel G Marini G Martellotti F Massa A Nigro E Pauli C Pigot A Rambaldi S Reucroft C.E Roos A Sciubba M Webster 《Physics letters. [Part B]》1981,104(4):330-334
The reactions π?d → K+ + MM and K?d → π+ + MM have been studied at 1.4 GeV/c to search for strange dibaryon states with quantum numbers Q = ?1, and S = ?1. No structures are found which could indicate the production of such states and upper limits for the cross sections are established. 相似文献
23.
S.T. Hood A. Hamnett C.E. Brion 《Journal of Electron Spectroscopy and Related Phenomena》1977,11(2):205-224
The construction and operation of an instrument which uses the techniques of coincidence counting and electron impact spectroscopy is reported for the study of molecular ionization at large momentum transfer in which the two outgoing electrons are detected at 45° to the incident beam. Variation of the incident energy provides binding-energy spectra for Xe, CH4 and H2O up to 45 eV. Alternatively variation of the azimuthal angle (symmetric, non-coplanar geometry) gives a measure of the electron momentum distribution for any selected orbital in the binding-energy spectrum. Momentum distributions for the four valence orbitals of H2O are compared with various wavefunctions from the literature. 相似文献
24.
25.
J.P. De Brion C. Bromberg T. Ferbel P. Slattery J. Cooper A. Seidl J.C. Vander Velde 《Physics letters. [Part B]》1974,52(4):477-480
We examine in detail the properties of low-mass systems produced in the inclusive reaction p + p → p + anything at 102 GeV/c. We find that the internal characteristics of these low-mass nucleon-multipion systems (the “anything”), at fixed values of mass (M), are similar to those found for produced hadrons in high-energy collisions at fixed incident hadron energies . The resemblance between the properties of the M2 system and the characteristics of πp collisions at s = M2 is particularly striking. 相似文献
26.
C.E. Brion K.H. Tan M.J. van der Wiel Ph.E. van der Leeuw 《Journal of Electron Spectroscopy and Related Phenomena》1979,17(2):101-119
The photoabsorption, photoionization and fragmentation of O2 have been studied using electron impact coincidence methods to obtain branching ratios and dipole oscillator strengths (cross-sections). The photoabsorption measurements cover the energy range 5–300 eV while the formation of electronic states of O2+ (photoelectron spectroscopy) and the resulting ionic fragmentation (photoionization mass spectrometry) are both measured from close to threshold up to photon energies of 75 eV. The binding energy spectra of O2 show peaks at 33, 47 and 57 eV in addition to those reported elsewhere in the literature. These peaks are assigned to multiple final ion states arising from photoionization of the inner valence orbitals. Structure in the O2+ electronic state partial oscillator strength curves is in good agreement with recent theoretical work which predicts the existence of several shape resonances. A quantitative picture of the dipole-induced breakdown of O2 is obtained for the energy range 12–75 eV. The photoionization efficiency is found to be constant above 20 eV. 相似文献
27.
Wing-Cheung Tam C.E. Brion 《Journal of Electron Spectroscopy and Related Phenomena》1974,3(6):467-477
The electron impact energy loss spectra of acetaldehyde, propionaldehyde and isobutyraldehyde have been studied at an impact energy of 100 eV and a scattering angle of two degrees. Transitions are tentatively assigned on the basis of term values calculated with respect to ionization potentials determined by photoelectron spectroscopy. Substituent effects on Rydberg orbital energies are discussed using Taft σ* values. 相似文献
28.
M.J. van der Wiel C.E. Brion 《Journal of Electron Spectroscopy and Related Phenomena》1973,1(4):309-318
The relative intensities for ionization to the lowest three electronic states of CO+ have been obtained by detecting forward scattered 3.5 keV electrons in coincidence with electrons ejected at 90°. Data are reported for energy losses of the projectile electron in the range of 18–50 eV. A simple relation is derived between our data, photoelectron intensities and the angular anisotropy parameter β. This relation appears to be fulfilled satisfactorily for a (photon) energy of 21.2 eV, for which photoelectron intensities and β are available. 相似文献
29.
The energy loss spectrum of 2.5 keV electrons, scattered by gaseous acetone through small angles, has been obtained in the region of the carbon K-edges. Discrete structure observed below the ionization threshold is interpreted as arising from the promotion of a carbon K-shell electron to Rydberg orbitals. Broad peaks observed above the K-edges are associated with the simultaneous transitions of a carbon K-shell and valence shell electrons (shake-up and shake-off processes). 相似文献
30.
The threshold electron impact spectrum of argon has been obtained in the energy range 24–35 eV using the sulphur hexafluoride electron scavenging technique. Structure is observed which may be due to single excitation, double excitation and temporary negative ion states. 相似文献