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1.
F. R. Graziani 《Zeitschrift fur Physik C Particles and Fields》1987,33(3):397-405
Using massive gauge invariant QCD we show explicity how power like corrections to \(\Pi _{\mu v} \left( q \right) = i\int {dx} e^{iq'x} \left\langle {0\left| {j_\mu ^{em} \left( x \right)\bar j_v^{em} \left( 0 \right)} \right|0} \right\rangle \) arise. Using our result for the 1/q 4 contribution, a one to one correspondence is made between the gluon condensate and the effective gluon mass. By relating this mass to, \(\langle 0|\frac{{\alpha _s }}{\pi }G_{\mu v}^2 |0\rangle \) a value ofm gluon=750 MeV is found at ?q 2=10 GeV2. In addition, within the context of dimensional regularization, a new technique for evaluating two loop momentum integrals with massive propagators is introduced. This method is a derivative of the Mellin transform technique that was applied to ladder diagrams in the days of Reggeisation. 相似文献
2.
Maurizio Lenarda Renzo Ganzerla Adriana Lisini Mauro Graziani Tristano Boschi 《Transition Metal Chemistry》1981,6(4):199-203
Summary Platinum(0) and palladium(0) complexes of the type: P2M(R1R2C=CR3R4) (P=trisubstituted phosphine; R1, R2, R3 and R4 are different groups having electron acceptor or electron donor properties; M=Pt or Pd) with so called pushpull olefins, have been prepared and characterized. In some cases unusual patterns in the n.m.r. spectra of olefinic protons were observed. The spectra were analyzed by computer simulation and general rules for ABMX patterns for this type of complexes are given. 相似文献
3.
Rodolfo Graziani Maurizio Vidali Umberto Casellato Pietro Alessandro Vigato 《Transition Metal Chemistry》1978,3(1):239-242
Summary The structure of the heterobinuclear complex of Cu2+ and [UO2]2+ with the tetraanionic ligand derived from the condensation of 1,2-diaminoethane witho-acetoacetylphenol has been determined from diffractometer data and refined to R = 5.2%. The crystals are monoclinic,P21/a, witha = 26.22(2),b = 14.79(2),c = 8.10(1) Å and = 104.65(5)°; Z = 4. The ligand employed has two different coordination sets of atoms, N2O2 and O2O2, two oxygen atoms being common to both donor sets. In the complex the copper atom, which is retained in the inner N2O2 chamber, is five coordinate being axially bonded to a solvent molecule, whilst the uranyl ion is incorporated in the outer O2O2 chamber. Another molecule of solvent is retained to preserve the preferred seven coordination of uranium. 相似文献
4.
Summary The structure of the heterobinuclear complex of Ni2+ and [U022]2+ with the tetraanionic ligand derived from the condensation of 1,2-diaminoethane with o-acetoacetylphenol has been determined from diffractometer data and refined to R = 7.2%. The crystals are monoclinic, P21 /a, with = 20.65(2), b = 8.58(1), c = 14.68(2) Å and = 97.78(5); Z = 4. The ligand employed has two different coordination sets of atoms, N2O2 and O2O2, two oxygen atoms being common to both donor sets. In the complex the nickel ion, which is four coordinate but not square planar, is retained in the inner N2O2 chamber, whilst the uranyl ion is incorporated in the outer O2O2 chamber. A molecule of solvent is retained to preserve the preferred seven coordination of uranium. 相似文献
5.
W. Daniel Carlisle David E. Fenton Patrick B. Roberts Umberto Casellato Pietro A. Vigato Rodolfo Graziani 《Transition Metal Chemistry》1986,11(8):292-295
Summary The crystal structure of the dinuclear complex [Cu2(C26H30-N4O2)(H2O)2](BF4)2 was determined by x-ray crystallography. The crystals are triclinic, P¯1, witha = 10.945(5),b = 8.703(5),c = 8.495(5) Å, = 103.86(3)°, = 105.73(3)°, = 85.77(3)°, V = 756 Å3 Dc = 1.65 g cm–3 for Z = 1. The copper(II) atoms are 5-coordinate and square-pyramidal. Selected bond distances are: Cu-N, 1.91 Å (mean); Cu-O(base) = 1.90(1) and 1.91(1) Å; Cu-O(apical) = 2.47(1) Å; There are O(water)-H ... F interionic hydrogen bonds in the structure. The Cu .. Cu distance is 2.847 Å. 相似文献
6.
EI Rodriguez Martinez CI Barriga-Paulino MI Zapata CC Chinchilla AM López-Jiménez CM Gómez 《BMC neuroscience》2012,13(1):104-23
ABSTRACT: BACKGROUND: The peri-adolescent period is a crucial developmental moment of transition from childhood to emergent adulthood. The present report analyses the differences in Power Spectrum (PS) of the Electroencephalogram (EEG) between late childhood (24 children between 8 and 13 years old) and young adulthood (24 young adults between 18 and 23 years old). RESULTS: The narrow band analysis of the Electroencephalogram was computed in the frequency range of 0--20 Hz. The analysis of mean and variance suggested that six frequency ranges presented a different rate of maturation at these ages, namely: low delta, delta-theta, low alpha, high alpha, low beta and high beta. For most of these bands the maturation seems to occur later in anterior sites than posterior sites. Correlational analysis showed a lower pattern of correlation between different frequencies in children than in young adults, suggesting a certain asynchrony in the maturation of different rhythms. The topographical analysis revealed similar topographies of the different rhythms in children and young adults. Principal Component Analysis (PCA) demonstrated the same internal structure for the Electroencephalogram of both age groups. Principal Component Analysis allowed to separate four subcomponents in the alpha range. All these subcomponents peaked at a lower frequency in children than in young adults. CONCLUSIONS: The present approaches complement and solve some of the incertitudes when the classical brain broad rhythm analysis is applied. Children have a higher absolute power than young adults for frequency ranges between 0-20 Hz, the correlation of Power Spectrum (PS) with age and the variance age comparison showed that there are six ranges of frequencies that can distinguish the level of EEG maturation in children and adults. The establishment of maturational order of different frequencies and its possible maturational interdependence would require a complete series including all the different ages. 相似文献
7.
Viviana De Luca Paolo Digiamberardino Giovanna Di Pasquale Salvatore Graziani Antonino Pollicino Elena Umana Maria Gabriella Xibilia 《Journal of Polymer Science.Polymer Physics》2013,51(9):699-734
Smart systems adapt to the surrounding environments in a number of ways. They are capable to scavenge energy from available sources, sense and elaborate external stimuli and adequately react. Electro Active Polymers are playing a main role in the realization of smart systems for applications if fields such as bio inspired and autonomous robotics, medicine, and aerospace. This paper focus on the possibility to use Ionic Polymer Metal Composites as a class of materials relevant to the realization of post silicon smart systems. The three main aspects of this new technology, i.e., fabrication methods, modeling, and applications are described with emphasis to most recent results. Attention is given to main challenges and shortcomings to be solved for technology, modelling, and control of IPMC based devices that need to be solved before this new technology can be fully exploited in real world applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 相似文献
8.
Tamer Shoeib Junfang Zhao Houssain EI Aribi Alan C. Hopkinson K. W. Michael Siu 《Journal of the American Society for Mass Spectrometry》2013,24(1):38-48
The fragmentations of [AA + M]+ complexes, where AA = Phe, Tyr, Trp, or His, and M is a monovalent metal (Li, Na, or Ag), have been exhaustively studied through collision-induced dissociation (CID) and through deuterium labeling. Dissociations of the Li- and Ag-containing complexes gave a large number of fragment ions; by contrast, the sodium/amino acid complexes have lower binding energies, and dissociation resulted in much simpler spectra, with loss of the entire ligand dominating. Unambiguous assignments of these fragment ions were made and formation mechanisms are proposed. Of particular interest are fragmentations in which the charge was retained on the organic fragment and the metal was lost, either as a metal hydride (AgH) or hydroxide (LiOH) or as the silver atom (Ag?). Caption for Graphical Abstract
CID products of Li+, Na+, and Ag+ complexes of Phe, Tyr, Trp, and His are reported and mechanisms by which they are formed are proposed. 相似文献
9.
Gilles Aubert Laure Blanc-Féraud Daniele Graziani 《Applied Mathematics and Optimization》2013,67(1):73-96
The paper is concerned with the analysis of a new variational model to restore point-like and curve-like singularities in biological images. To this aim we investigate the variational properties of a suitable energy which governs these pathologies. Finally in order to realize numerical experiments we minimize, in the discrete setting, a regularized version of this functional by fast descent gradient scheme. 相似文献
10.
Doyle AW Fick J Himmelhaus M Eck W Graziani I Prudovsky I Grunze M Maciag T Neivandt DJ 《Langmuir : the ACS journal of surfaces and colloids》2004,20(21):8961-8965
Structural deformations of lipid hybrid bilayer membranes induced by signal peptideless (SPL) proteins have been studied for the first time using the inherently surface specific nonlinear optical technique of sum frequency generation vibrational spectroscopy. Specifically, deformations of 1,2-distearoylphosphatidylglycerol(DSPG) membranes induced by interaction with FGF-1, a SPL protein which is released asa function of cellular stress through a nonclassical pathway, have been investigated. FGF-1 was found to induce lipid alkyl chain deformations in previously highly ordered DSPG membranes at the extremely low concentration of 1 nM at 60 degrees C. The deformation process was shown to exhibit a degree of reversibility upon removal of the protein by rinsing with buffer solution. 相似文献