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331.
Use of LiPF6 in EC:DEC as electrolyte has allowed electrochemical extraction of Li from LiV1−yMyS2 and LiTi1−yMyS2 (M=Cr or Fe). The data show access not only to the Ti(IV)/Ti(III) and V(IV)/V(III) redox couples, but also to the V(V)/V(IV) and Fe(III)/Fe(II) couples in these layered sulfides. However, the Cr(IV)/Cr(III) couple could not be accessed. The concept of redox-couple pinning is outlined and applied to the V(V)/V(IV) and Fe(III)/Fe(II) couples, which are pinned at the top of the S-3p bands. Holes associated with the “pinned” couples occupy orbitals of dominant S-3p character, but they have sufficient cation-3d character to prevent condensation of the holes into p-p antibonding states of disulfide bonds. Strong covalent bonding in the pinned couples creates itinerant-electron states in the partially occupied couples. Application to the metallic, ferromagnetic thiospinel Cu[Cr2]S4 favors location of the itinerant holes in states of a pinned Cu(II)/Cu(I) couple having primarily S-3p character. 相似文献
332.
Qi‐Long Zhang Zhi‐Lei Wu Hong Xu Bin Zhai Yu‐Fang Wang Guang‐Wei Feng Ya‐Li Huang 《无机化学与普通化学杂志》2016,642(5):414-418
The tetranuclear nickel cluster {[Ni4(L)4(C2H5OH)4] · 7H2O} ( 1 ) was synthesized based on the tridentate Schiff base ligand H2L = 1‐phenyl‐3‐[(2‐hydroxyphenyl)imino]‐1‐butanone. The structure of 1 was determined by single‐crystal X‐ray diffraction. It exhibits a discrete [Ni4O4] cluster. Magnetic studies indicate that ferromagnetic interactions exist within compound 1 . Furthermore, thermogravimetric analysis and PXRD patterns in various solvents reveal thermal and solvent stability of compound 1 . 相似文献
333.
The mechanism of the growth of the dendrites in the Ni-Cu films is studied by comparing them with the aggregates obtained by Monte Carlo (MC) simulations according to the diffusion-limited aggregation (DLA) model. The films were grown by electrodeposition. The structural analysis of the films carried out using the x-ray diffraction showed that the films have a face-centered cubic structure. Scanning electron microscope (SEM) was used for morphological observations and the film compositions were determined by energy dispersive x-ray spectroscopy. The observed SEM images are compared with the patterns obtained by MC simulations according to DLA model in which the sticking probability, P between the particles is used as a parameter. For all samples between the least and the densest aggregates in the films, the critical exponents of the density-density correlation functions, α were within the interval 0.160 ± 0.005-0.124 ± 0.006, and the fractal dimensions, Df, varies from 1.825 ± 0.006 to 1.809 ± 0.008 according to the method of two-point correlation function. These values are also verified by the mass-radius method. The pattern with α and Df within these intervals was obtained by MC simulations to DLA model while the sticking probability, P was within the interval from 0.35 to 0.40 obtained by varying P (1-0.001). The results showed that the DLA model in this binary system is a possible mechanism for the formation of the ramified pattern of Ni-Cu within the Ni-rich base part of the Ni-Cu films due to the diffusive characteristics of Cu. 相似文献
334.
Antiferromagnetic/ferromagnetic (AF/F) NiMn/Fe37Co48Hf15 films were investigated with respect to their exchange bias, in-plane unidirectional anisotropy, polarisation and high frequency behaviour. After deposition, carried out by r.f. magnetron sputtering, the films were post-annealed for 4 h at 300 °C in a static magnetic field, in order to induce exchange-bias, which results in a unidirectional anisotropy. Dependent on the presence of a bi-layer or multi-layer sandwich structure the films show a different exchange-bias field-ferromagnetic inter-layer thickness behaviour with exchange-bias fields μ0?Heb between 2 and 10 mT. The in-plane uniaxial (single film) or unidirectional anisotropy fields μ0*HUF were between 4 and 18 mT. This results in a significant increase of the cut-off frequency in the GHz range in comparison to a single Fe37Co48Hf15 film, which is shown by frequency-dependent permeability plots. High damping in the imaginary part of the permeability, i.e., high resonance line broadening could be observed for films with high coercivity μ0*Hc of around 7 mT in the easy axis of magnetisation. 相似文献
335.
N doped TiO is nonmagnetic, in which spin-split impurity states are not induced near the Fermi energy (EF) by N dopant. N doped TiO2 along with transition-metal (TM) doped TiO is magnetic, in which spin-split impurity states are induced across EF. The magnetic moment is determined by the 3d4s electron configurations and the valence states of TM-dopant ions when they substitute Ti. Hence, the origin of ferromagnetism of N doped TiO2 and TiO is not closely related to the width of the band gaps of host oxides, but would be crucially related to that if the dopant can induce spin-split impurity states near EF. 相似文献
336.
Ferromagnetic nanoparticles insertions in nematic liquid crystals (NLC) in twisted configuration are studied and a theoretical model is proposed to explain the results. Experimental observation revealed that nanoparticles tend to overcrowd in long strings parallel to the rubbing direction of the alignment substrate of the LC cell. Their behavior under external field was studied and their interaction with their nematic host is described using elastic continuum theory. 相似文献
337.
Room-temperature magnetic properties of planar nanowire arrays of Fe have been studied using comprehensive analysis of FMR and magnetometry data. It has been shown that the Fe NWs are ferromagnetic at room temperature and their magnetic properties are mainly governed by shape anisotropy. Combining parameters derived from the FMR study with experimental data of magnetometry, simulations of hysteresis loops have been performed based on Stoner–Wohlfarth approach. Calculations show that magnetisation reversal of Fe NWs has a coherent-rotation type of localised character. As NW thickness decreases, localisation of the magnetisation reversal mode is found to enhance due to increased inhomogeneity of thinner NWs. 相似文献
338.
339.
H.K. Lachowicz T. Kulik R. ?uberek L. Ma?kiński M. Ku?miński A. ?lawska-Waniewska J.S. Muñoz 《Journal of magnetism and magnetic materials》1998,190(3):253
Co67Fe4Mo2Si17B11 metallic glass ribbon has been subjected to the isothermal annealing at temperatures in the range 250–600°C so as to produce a series of samples with gradually coarser microstructure. For this series of samples a giant increase of the coercivity, exceeding five orders of magnitude, is observed. It shows a possibility to tailor soft or hard magnets using the same parent material. An abrupt increase of the coercivity occurs in a relatively small range of annealing temperatures between 480 and 520°C, and is mainly due to a strengthening of the pinning effect of the precipitates (fine crystalline structure) on the domain walls. Samples annealed at higher temperatures become fully crystallized. First, the metastable phase(s) is created which decomposes to the stable phases at still higher temperature. Coercivity for fully crystallized samples shows first a narrow plateau and afterwards a gradual decrease of its value with increasing temperature of annealing. Magnetic and microstructural properties of the samples, annealed at various temperatures, were investigated applying a number of complementary techniques including DSC and TGM methods, X-ray diffraction, TEM, strain-modulated FMR spectroscopy as well as conventional magnetic measurements. 相似文献
340.
本文经过推导,找到了一种可用来计算电力电子变流器电路中周期非正弦电流在铁磁器件中引起涡流损耗的微分电流法,并用实例说明了它的应用,证明了它较传统的Fourier谐波分析方法简单、方便,有实用价值。 相似文献