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861.
We aimed to investigate whether exposure to the Chinese famine (1959–1961) in early life was associated with depression in adulthood. We included 17,505 participants from the China health and retirement longitudinal study (CHARLS). Participants were classified into indirect and direct exposure groups. And the directly exposure groups including prenatal, childhood, adolescence/adult exposure groups. Depression was diagnosed by Center for Epidemiological Studies Depression Scale-10 (CES-D) score. Multivariate logistic regression model was used to calculate the odd ratios (ORs) and 95% confidence intervals (CIs) of depression. In women, prenatal, childhood, adolescence/adult exposure groups had higher depression risk than indirect exposure group (OR = 1.46, 1.40, and 1.67, respectively). However, there was no significant association between famine exposure and depression among men. Exposure to famine during prenatal (OR: 1.48; 95% CI: 1.07–2.06), childhood (OR: 1.47; 95% CI: 1.13–1.91), and adolescence/adult (OR: 1.63; 95% CI: 1.24–2.15) period were associated with depression among subjects living in rural, but not those living in urban. Exposure to the Chinese famine in early life had sex and area-specific associations with depression. 相似文献
862.
Yi-Ming Yu 《Journal of Academic Ethics》2018,16(2):173-193
This study compared the effects of three education models, namely, the bag-of-virtues (BV), values clarification (VC), and virtue ethics (VE) models, through qualitative and quantitative approaches. In the quantitative study (Study 1), a between-subjects design was adopted in sampling 120 freshman cadets from a Taiwanese military academy. For the qualitative study (Study 2), focus group interviews were conducted with 10 freshman cadets. The results show that the VC model was the most effective among the three moral education models, followed by the VE and BV models. 相似文献
863.
Self-determination theory proposes that the extent to which students’ motivation is self-determined is critical to learning outcomes. Based on occasional research evidence and our perceptions, we hypothesize that college students in certain majors have profiles that are higher in self-determined motivation than students in other majors. Specifically, our primary hypothesis is that students in the social sciences and humanities tend to be more self-determined, whereas students in business-related majors tend to be less self-determined. The results from two studies using large samples and advanced analytical methods support the primary hypotheses. Comparison results were also obtained for other majors (e.g., engineering and natural sciences), and supplemental analyses supported the critical role of self-determined motivation in learning outcomes among students in all majors. Study 2 also found support for two mechanisms for such differences, i.e., the majors’ learning climates and students’ individual differences in autonomous functioning. The current evidence suggests the importance of promoting more humanistic learning environments in certain academic disciplines. 相似文献
864.
Whether abduction is treated as an argument or as an inference, the mainstream view presupposes a tight connection between abduction and inference to the best explanation (IBE). This paper critically evaluates this link and supports a narrower view on abduction. Our main thesis is that merely the hypothesis-generative aspect, but not the evaluative aspect, is properly abductive in the sense introduced by C. S. Peirce. We show why equating abduction with IBE (or understanding them as inseparable parts) unnecessarily complicates argument evaluation by levelling the status of abduction as a third reasoning mode (besides deduction and induction). We also propose a scheme for abductive argument along with critical questions, and suggest retaining abduction alongside IBE as related but distinct categories. 相似文献
865.
Characteristics of the interaction of Cu-rich precipitates with irradiation-produced defects in α-Fe
A. C. Arokiam A. V. Barashev D. J. Bacon Yu. N. Osetsky 《Philosophical Magazine Letters》2013,93(9):491-501
The interaction between copper-rich precipitates in α-iron and either vacancies or self-interstitial atoms and their clusters is studied by atomic-scale modelling. Results are compared with predictions of elasticity theory and interpreted in terms of size misfit of precipitates and defects, and the modulus and cohesive energy differences between iron and copper. Interstitial defects are repelled by precipitates at large distance but, like vacancies, attracted at small distance. Hence, copper precipitates in iron can be sinks for both vacancy and interstitial defects, and can act as strong recombination centres under irradiation conditions. This leads to a tentative explanation for the mixed Cu–Fe structure of precipitates and the absence of precipitate growth under neutron irradiation conditions. More generally, both vacancy and interstitial defects may be strongly bound to precipitates with weaker cohesion than the matrix. 相似文献
866.
A formalism for optimized many body (OMB) potentials to describe the interatomic interactions in fcc metals is described. The OMB approach is based on the Tersoff potential, widely used to describe covalently bonded materials, and is closely related to the charge optimized many body (COMB) potential formalism for oxides. OMB extends to first nearest neighbors only, and employs a third-order Legendre polynomial to distinguish fcc and hcp structures, the strength of which can be adjusted to match the intrinsic stacking fault energy to arbitrary precision. The potential also predicts generalized stacking fault energy curves that are in very close agreement to the values determined from electronic-structure calculations. This potential is thus well-suited to investigating mechanical properties such as plastic deformation at the atomic scale. 相似文献
867.
M. Yu. Gutkin A. L. Kolesnikova I. A. Ovid'Ko N. V. Skiba 《Philosophical Magazine Letters》2013,93(12):651-657
A theoretical model is presented which describes a new mechanism of plastic deformation in fine-grained materials. In the framework of the model, rotational deformation occurs via motion of dipoles of grain-boundary disclinations and is associated with the emission of lattice dislocations from grain boundaries into adjacent grain interiors. Ranges of defect system parameters are identified in which the disclination motion is energetically favourable. It is shown that the mechanism can contribute to plastic flow in fine-grained materials prepared by highly non-equilibrium methods such as ball milling, severe deformation and high-pressure compaction. 相似文献
868.
The interaction between a glissile cluster of self-interstitial atoms and a vacancy has been studied in f -Fe by atomistic modelling and elasticity theory. It was found that vacancies can annihilate only with the cluster edge. Vacancies inside the cluster glide prism do not annihilate with interstitials but affect the cluster dynamic properties. Depending on the cluster size and ambient temperature, these vacancies reduce or even prevent cluster motion. Qualitative differences in the results of atomistic and elasticity theory approaches were found, thereby demonstrating the need for the atomistic approach. 相似文献
869.
O.Yu. Kontsevoi O. N. Mryasov Yu. N. Gornostyrev A. J. Freeman M. I. Katsnelson A. V. Trefilov 《Philosophical Magazine Letters》2013,93(5):427-433
The electronic structure of the 100 {010} edge dislocation in NiAl has been calculated using the real-space tight-binding linear muffin-tin orbital recursion method with a self-consistent treatment of electron density redistribution effects in the dislocation core. We demonstrate that quasilocalized states may exist in this metallic system as a result of specific lattice distortions in the dislocation core with 'broken bonds'. 相似文献
870.
Although it is well known that traditional metals and alloys will become brittle at low temperatures, the effect of low temperature on the mechanical properties of bulk metallic glasses (BMGs) is yet to be fully understood. In this research, the mechanical properties of Ce68Al10Cu20Co2 BMG are investigated at low temperatures. It is found that the yield strength of the Ce-based BMG increases significantly with the decrease of temperature. The elastic moduli of the BMG also increase monotonically with the drop of temperature, indicating the continuous stiffening of the BMG, while both Poisson's ratio and global plasticity decline at low temperatures. It is considered that the stiffer atomic bonds of the Ce-based BMG at low temperatures result in the increase of strength, and the higher energy required for nucleation of shear bands also leads to the increase in yield strength. 相似文献