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931.
Edward Z. Tronick Ph.D. 《Psychoanalytic Inquiry》2013,33(3):473-491
The question of the uniqueness of relationships is examined: How do relationships come to be unique? What are some of the features of their uniqueness? And how can relationships, be it the mother—infant relationship or the patient—therapist relationship, have unique rather than archetypical effects on other relationships? A model of relationship uniqueness is presented that argues that mother and infant, and patient and therapist, co-create dyadic states of consciousness—states of making implicit and explicit sense of the world—out of their normally messy exchanges of age-possible meanings. These co-creative processes lead to change in the infant's and child's state of knowing the world, and also change the way the patient makes sense of the world and ways of being with others. Additionally presented are (I) a critique of attachment theory's assumption that the mother—infant relationship is the prototype of later relationships; (2) a critique of models of therapeutic change that see adult analysis as working primarily in the same domain as the workings of the mother-infant relationship; (3) a brain model of co-creative relational processes, Relational Activation Patterns (RAPs); and (4) possible psychodynamic processes in infants. 相似文献
932.
Dynamic balance between grain refinement and grain growth during high-pressure torsion of Cu powders
Haiming Wen Rinat K. Islamgaliev Konstantin M. Nesterov Ruslan Z. Valiev Enrique J. Lavernia 《Philosophical Magazine Letters》2013,93(8):481-489
High-pressure torsion (HPT) was applied to unmilled coarse-grained (CG) Cu powders with low initial dislocation density and cryomilled nanocrystalline (nc) Cu powders with high initial dislocation density, with identical processing parameters. HPT of unmilled CG Cu powders resulted in exceptional grain refinement and increase in dislocation density, whereas significant grain growth and decrease in dislocation density occurred during HPT of cryomilled nc Cu powders. Equilibrium structures were achieved under both conditions, with very similar stable grain sizes and dislocation densities, suggesting dynamic balances between deformation-induced grain refinement and grain growth, and between deformation-induced dislocation accumulation and dislocation annihilation. The equilibrium structures are governed by these two dynamic balances. 相似文献
933.
A new modulated structure with a superlattice having parameters a = 2.209nm, b = 3.826nm, c = 1.037nm and f = g = n = 90 has been found in GaN nanoparticles synthesized by a dc arc plasma method. The nanoparticles transformed further into particles with holes at their centres under electron-beam irradiation during high-resolution electron microscopy observations. At the same time, Ga atoms were extruded on to the surface of the nanoparticles and formed an amorphous layer. A series of simulations of high-resolution images and electron diffraction patterns revealed that the modulation could be attributed to aggregations of N vacancies founded during the electron bombardment. Molecular mechanics calculations show that the aggregation of N vacancies is far more energetically favourable than that of Ga vacancies. The stability of the GaN particles is discussed. 相似文献
934.
935.
Grain growth subjected to the interplay of stochastic and curvature-driven mechanisms in a single-phase system has been investigated. Numerical results have shown that when the grains are smaller than several tens of nanometres the dominating mechanism is stochastic diffusion control of boundaries. As the grains grow the influence of the deterministic curvature-driven mechanism increases and finally controls the process. In terms of finite-difference solutions to the Fokker–Planck continuity equation, the predicted grain size approaches a log-normal distribution, which agrees well with experimental observations. 相似文献
936.
937.
Transformation and misfit dislocations are used to describe the motion of glissile interfaces with one set of misfit dislocations in the framework of the Frank?Bilby equation. The sweep of these glissile interfaces brings about an invariant-plane-strain type shape deformation. Our approach explains the glissile motion of martensitic interfaces and small-angle symmetrical tilt grain boundaries. It is consistent with the phenomenological theory of martensite crystallography but more flexible. 相似文献
938.
The roughening kinetics of Ti1? x Al x N (0?x? 1) films 600 nm thick synthesized by reactive dc magnetron sputtering on Si(100) substrates has been investigated by atomic force microscopy (AFM). The quantification of surface roughening was achieved by calculation of both vertical root-mean-square roughness and lateral correlation lengths of the film surface using the height-height correction functions of measured AFM images. For all the Ti1? x Al x N films, a steady roughness exponent α = 0.94 ± 0.03 was determined. The evolution of the surface topography as a function of Al concentration is discussed in terms of the competition between surface diffusion and shadowing instability during sputter deposition. 相似文献
939.
The superheating behaviour of embedded particles induced by semicoherent interfaces has been observed in many circumstances. In this paper, a phenomeno‐ logical model for melt nucleation on misfit dislocations at a semicoherent interface is proposed. A kinetic limit for semicoherent-interface-induced superheating, which is in good agreement with the results of experiments and computer simulations, is derived from this model. Calculations and analyses based on the model reveal that melting prefers to initiate at the semicoherent interface and that superheating of embedded particles is possible for a melt nucleation contact angle less than 90°. Among the matrix-dependent parameters, the contact angle and the shear modulus of the matrix are found to be dominant in determining the superheating of embedded particles. 相似文献
940.
J. C. Jiang † E. I. Meletis C. L. Chen Y. Lin Z. Zhang W. K. Chu 《Philosophical Magazine Letters》2013,93(7):443-450
We report the detailed microstructural study of a CaCu3Ti4O12 (CCTO) thin film using transmission electron microscopy (TEM). The CCTO thin film studied in this work was deposited on a (001)-oriented LaAlO3 (LAO) substrate by pulsed-laser ablation and has a high dielectric constant of about 104 at 1?MHz at room temperature; however, the mechanism for such a dielectric property is not yet understood. Plan-view TEM studies show that the CCTO samples have orthogonal domain structures with the edge nearly parallel to either the [100] or the [010] direction of the CCTO. A minor anatase TiO2 phase was found at the domain boundaries. The CCTO and the TiO2 phases are separated by an amorphous-like layer that has a thickness of several nanometres. Cross-sectional TEM studies reveal that both CCTO and TiO2 in the films are c axis oriented with a very sharp interface to the LAO-(001) substrate and possess a unique crystallographic orientation relationship of (001) CCTO //(001)TiO 2 //(001) LAO and [100] CCTO //[100] TiO 2 //[100] LAO. The Rutherford back-scattering ion chanelling studies suggest a composition of Ca1.5Cu3Ti5.5O16 for the film, in which the extra calcium, titanium and oxygen form the anatase TiO2 phase and amorphous calcium oxide layer that separates the CCTO and TiO2 phases. Such nanocomposite-like structures may provide an important clue to the mechanism of the dielectric property of these films. 相似文献