全文获取类型
收费全文 | 145篇 |
免费 | 4篇 |
专业分类
化学 | 31篇 |
数学 | 17篇 |
物理学 | 101篇 |
出版年
2023年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 12篇 |
2011年 | 4篇 |
2010年 | 5篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2007年 | 3篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2003年 | 1篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1996年 | 30篇 |
1995年 | 22篇 |
1994年 | 11篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1967年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有149条查询结果,搜索用时 15 毫秒
81.
Abe F Akimoto H Akopian A Albrow MG Amendolia SR Amidei D Antos J Anway-Wiese C Aota S Apollinari G Asakawa T Ashmanskas W Atac M Auchincloss P Azfar F Azzi-Bacchetta P Bacchetta N Badgett W Bagdasarov S Bailey MW Bao J de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Bauer G Baumann T Bedeschi F Behrends S Belforte S Bellettini G Bellinger J Benjamin D Benlloch J Bensinger J Benton D Beretvas A Berge JP Berryhill J Bertolucci S Bhatti A Biery K Binkley M Bisello D Blair RE Blocker C 《Physical review D: Particles and fields》1996,54(1):735-742
82.
83.
Subham Majumdar EV Sampathkumaran St Berger M Della Mea H Michor E Bauer M Brando J Hemberger A Loidl 《Pramana》2002,58(5-6):777-782
Recently, the solid solution Ce2Au1−
x
Co
xSi3 has been shown to exhibit many magnetic anomalies associated with the competition between magnetic ordering and the Kondo
effect. Here we report high pressure electrical resistivity of Ce2AuSi3, ac susceptibility (X) and magnetoresistance of various alloys of this solid solution in order to gain better knowledge of the magnetism of these
alloys. High pressure resistivity behavior is consistent with the proposal that Ce2AuSi3 lies at the left-hand side of the maximum in Doniach’s magnetic phase diagram. The ac X data reveal that there are in fact two magnetic transitions, one at 2 K and the other at 3 K for this compound, both of which
are spin-glass-like. However, as the Co concentration is increased, antiferromagnetism is stabilized for intermediate compositions
before attaining non-magnetism for the Co end member. 相似文献
84.
Larin I McNulty D Clinton E Ambrozewicz P Lawrence D Nakagawa I Prok Y Teymurazyan A Ahmidouch A Asratyan A Baker K Benton L Bernstein AM Burkert V Cole P Collins P Dale D Danagoulian S Davidenko G Demirchyan R Deur A Dolgolenko A Dzyubenko G Ent R Evdokimov A Feng J Gabrielyan M Gan L Gasparian A Gevorkyan S Glamazdin A Goryachev V Gyurjyan V Hardy K He J Ito M Jiang L Kashy D Khandaker M Kingsberry P Kolarkar A Konchatnyi M Korchin A Korsch W Kowalski S Kubantsev M Kubarovsky V Li X Martel P 《Physical review letters》2011,106(16):162303
High precision measurements of the differential cross sections for π0 photoproduction at forward angles for two nuclei, 12C and 208Pb, have been performed for incident photon energies of 4.9-5.5 GeV to extract the π0→γγ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The π0→γγ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is Γ(π0→γγ)=7.82±0.14(stat)±0.17(syst) eV. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current Particle Data Group average of this fundamental quantity, and it is consistent with current theoretical predictions. 相似文献
85.
Christopher M. Benton Chang Kee Lim Caje Moniz Donald J. L. Jones 《Rapid communications in mass spectrometry : RCM》2011,25(24):3749-3757
An ultra‐high‐performance liquid chromatography/electrospray ionisation tandem mass spectrometry system is described for the separation and characterisation of uroporphyrinogen, heptacarboxylic acid porphyrinogen, hexacarboxylic acid porphyrinogen, pentacarboxylic acid porphyrinogen and coproporphyrinogen. The separation was carried out on a 100 mm × 2.1 mm Thermo‐Hypersil BDS column (2.4 µm average particle size) by gradient elution with a mixture of acetonitrile, methanol and 1 mol/L aqueous ammonium acetate buffer, pH 5.16, as eluent. The fragmentation pattern of each compound was established by collision‐induced dissociation tandem mass spectrometry. The most characteristic fragmentation was ring opening at one of the four methylene bridges of the protonated porphyrinogen molecule followed by further cleavages of methylene bridges linking the four pyrrole rings at various points to give product ions with methylenepyrrolenine, methylene‐dipyrrolenine and methylene‐tripyrrolenine structures. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
86.
Contributions to Doeblin's theory of Markov processes 总被引:1,自引:0,他引:1
87.
The reproducibility of a programmed-scan monochromator with stationary dispersion optics was evaluated by means of analysis of variance (ANOVA). The spectrometer used an optical multiplexer coupled with glass-fiber optic light-guides to a multiple entrance-slit spectrometer employing a photomultiplier as the detector. With this spectrometer, 15 emission intensity measurements at the lithium resonance line wavelength (670.7 nm) were collected for five rotations of the optiplexer mirror under four different emission situations: flame background emission at 670.7 nm, lithium emission from an acetylene-air flame in the absence of an ionization buffer, lithium emission from an acetylene-air flame in the presence of an ionization buffer, and tungsten lamp emission at 670.7 nm. For all four situations, the ANOVA results showed that instrumental changes which occurred during mirror rotation in the optiplexer were a significant source of signal variation compared with factors not associated with mirror rotation, i.e., photon shot noise, source fluctuation noise, and electronic drift. The actual magnitude of the signal variability introduced during mirror rotation, however, was found to be quite small, producing an average relative standard deviation of only 0.76% for the signal. 相似文献
88.
This paper reports results from the first measurements made on the exterior of a LEO spacecraft of mean dose equivalent rate and average quality factor as functions of shielding depth for shielding less than 1 g/cm2 Al equivalent. Two sets of measurements were made on the outside of the Mir Orbital Station; one near solar maximum in June 1991 and one near solar minimum in 1997. Absorbed dose was measured using stacks of TLDs. LET spectrum from charged particles of LET infinity H2O > o r= 5keV/micrometers was measured using stacks of CR-39 PNTDs. Results from the TLD and PNTD measurements at a given shielding depth were combined to yield mean total dose rate, mean dose equivalent rate, and average quality factor. Measurements made near solar maximum tend to be greater than those made during solar minimum. Both mean dose rate and mean dose equivalent rate decrease by nearly four orders of magnitude within the first g/cm2 shielding illustrating the attenuation of both trapped electrons and low-energy trapped protons. In order to overcome problems with detector saturation after standard chemical processing, measurement of LET spectrum in the least shielded CR-39 PNTD layer (0.005 g/cm2 Al) was carried out using an atomic force microscope. 相似文献
89.
90.