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1.
Heavy ion irradiation in the electronic stopping power region induces macroscopic dimensional change in metallic glasses and introduces magnetic anisotropy in some magnetic materials. The present work is on the irradiation study of ferromagnetic metallic glasses, where both dimensional change and modification of magnetic anisotropy are expected. Magnetic anisotropy was measured using Mössbauer spectroscopy of virgin and irradiated Fe40Ni40B20 and Fe40Ni38Mo4B18 metallic glass ribbons. 90 MeV 127I beam was used for the irradiations. Irradiation doses were 5×1013 and 7.5×1013 ions/cm2. The relative intensity ratios D 23 of the second and third lines of the Mössbauer spectra were measured to determine the magnetic anisotropy. The virgin samples of both the materials display in-plane magnetic anisotropy, i.e., the spins are oriented parallel to the ribbon plane. Irradiation is found to cause reduction in magnetic anisotropy. Near-complete randomization of magnetic moments is observed at high irradiation doses. Correlation is found between the residual stresses introduced by ion irradiation and the change in magnetic anisotropy. 相似文献
2.
This paper reports the use of improved numerical approaches to modelling extraction profiles, and shows that the approach substantially reduces statistical prediction uncertainties compared to those obtained on the basis of a three-point extrapolation from the later part of the extraction curve. Numerical fitting of manually obtained polycyclic aromatic hydrocarbon extraction data to a spherical particle diffusion model showed uncertainties typically reduced by a factor of three (with extremes at 1.02 and 770). Application to pressurised fluid extraction study of pelletised poly(vinylchloride) containing 30 mass% di(2-ethylhexyl)phthalate also showed good improvements. However, this high precision data showed small but significant lack of fit resulting in residual correlation and visibly biased prediction (more so than simple extrapolation). Re-fitting and uncertainty estimation using a first-order autoregression approximation to the covariance matrix produced more realistic uncertainty estimates and closer parameter estimates and is accordingly recommended for treating residual correlation from other causes, but did not entirely alleviate the problem. Different shape models (spherical, plane sheet and cylindrical) were applied without accounting fully for fitting error, and particle size effects were eliminated by modelling a simple size distribution. However, an approximate model based on linearly concentration-dependent diffusion coefficient showed excellent fit, confirming concentration-dependence as the most likely cause. This semiempirical model led to an uncertainty in total extractable material, at 0.2% of the total extractable value (with allowance for correlation). This is potentially good enough for recovery estimation and correction in certification of reference materials for validation purposes. 相似文献
3.
4.
We prove that a parabolic unitalU in a translation plane of orderq
2 with kernel containing GF(q) is a Buekenhout-Metz unital if and only if certain Baer subplanes containing the translation line of meetU in 1 moduloq points. As a corollary we show that a unital 16-03 in PG(2,q
2) is classical if and only if it meets each Baer subplane of PG(2,q
2) in 1 moduloq points. 相似文献
5.
In subnormal glow discharge under d.c. excitation at different pressure in a varying transverse magnetic field (0 to 30 G)
some measurements have been carried out for various initial average tube currents. The voltage across the discharge increases
and average tube current and residual current decreases in the magnetic field. With the help of Beckman’s expression [4] for
the axial field and the electron density distribution in a transverse magnetic field the observed variation of current and
voltage can be satisfactorily explained. The variation of axial electric field with transverse magnetic field can be represented
to a fair degree of accuracy by the derived equation. The behaviour of residual current with magnetic field has been observed
in these oscillations. 相似文献
6.
S. G. Barwick 《Geometriae Dedicata》1994,52(2):175-180
We define Buekenhout unitals in derivable translation planes of dimension 2 over their kernel and provide a characterization of these unitals. We use this result to improve the characterization of classical unitals given by Lefèvre-Percsy [13] and Faina and Korchmáros [7]. 相似文献
7.
Barwick Vicki Ellison Stephen L. R. Gjengedal Elin Magnusson Bertil Molinier Olivier Patriarca Marina Sibbesen Lorens Vanlaethem Nicole Vercruysse Isabelle 《Accreditation and quality assurance》2017,22(5):253-263
Accreditation and Quality Assurance - Eurachem held a workshop on method validation in analytical sciences in Gent, Belgium, on 9–10 May 2016. A summary of the working group discussions is... 相似文献
8.
A multisecret threshold scheme is a system which protects a number of secret keys among a group of n participants. There is a secret sK associated with every subset K of k participants such that any t participants in K can reconstruct the secret sK, but a subset of w participants cannot get any information about a secret they are not associated with. This paper gives a construction for
the parameters t = 2, k = 3 and for any n and w that is optimal in the sense that participants hold the minimal amount of information.
Communicated by: P. Wild 相似文献
9.
10.
Achterberg A Ackermann M Adams J Ahrens J Andeen K Atlee DW Bahcall JN Bai X Baret B Bartelt M Barwick SW Bay R Beattie K Becka T Becker JK Becker KH Berghaus P Berley D Bernardini E Bertrand D Besson DZ Blaufuss E Boersma DJ Bohm C Bolmont J Böser S Botner O Bouchta A Braun J Burgess C Burgess T Castermans T Chirkin D Christy B Clem J Cowen DF D'Agostino MV Davour A Day CT De Clercq C Demirörs L Descamps F Desiati P Deyoung T Diaz-Velez JC Dreyer J Dumm JP Duvoort MR Edwards WR Ehrlich R 《Physical review letters》2006,97(22):221101
On 27 December 2004, a giant gamma flare from the Soft Gamma-Ray Repeater 1806-20 saturated many satellite gamma-ray detectors, being the brightest transient event ever observed in the Galaxy. AMANDA-II was used to search for down-going muons indicative of high-energy gammas and/or neutrinos from this object. The data revealed no significant signal, so upper limits (at 90% C.L.) on the normalization constant were set: 0.05(0.5) TeV-1 m;{-2} s;{-1} for gamma=-1.47 (-2) in the gamma flux and 0.4(6.1) TeV-1 m;{-2} s;{-1} for gamma=-1.47 (-2) in the high-energy neutrino flux. 相似文献