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41.
E. L. Gromnitskaya A. G. Lyapin O. V. Stalgorova I. V. Danilov V. V. Brazhkin 《JETP Letters》2013,96(12):789-793
The elastic moduli and volume of H2O-D2O (1: 1) isotopically mixed ice (solid solution) have been studied at the solid-phase amorphization of normal 1h ice under compression at a temperature of 77 K and at the transition from high-density amorphous ice to low-density amorphous ice with subsequent successive crystallization to cubic (1c) and hexagonal (1h) ice at isobaric (0.05 GPa) heating. Comparison of the results with the respective data for H2O and D2O ices indicates that the observed concentration (in the isotopic composition) dependences of the elastic moduli and their derivatives for different phases of ice at isotopic hydrogen substitution in the H2O, H2O-D2O (1: 1), and D2O chain can be both monotonic and significantly nonmonotonic. 相似文献
42.
Khalil EL KHATABI Ilham AANOUZ Reda El-MERNISSI Atul Kumar SINGH Mohammed Aziz AJANA Tahar LAKHLIFI Shashank KUMAR Mohammed BOUACHRINE 《Turkish Journal of Chemistry》2021,45(3):647
Alzheimer’s disease (AD) is a multifactorial and polygenic disease. It is the most prevalent reason for dementia in the aging population. A dataset of twenty-six 1,2,3-triazole-based derivatives previously synthetized and evaluated for acetylcholinesterase inhibitory activity were subjected to the three-dimensional quantitative structure-activity relationship (3D-QSAR) study. Good predictability was achieved for comparative molecular field analysis (CoMFA) (Q2 = 0.604, R2 = 0.863, rext2 = 0.701) and comparative molecular similarity indices analysis (CoMSIA) (Q2 = 0.606, R2 = 0.854, rext2 = 0.647). The molecular features characteristics provided by the 3D-QSAR contour plots were quite useful for designing and improving the activity of acetylcholinesterase of this class. Based on these findings, a new series of 1,2,3-triazole based derivatives were designed, among which compound A1 with the highest predictive activity was subjected to detailed molecular docking and compared to the most active compound. The selected compounds were further subjected to 20 ns molecular dynamics (MD) simulations to study the comparative conformation dynamics of the protein after ligand binding, revealing promising results for the designed molecule. Therefore, this study could provide worthy guidance for further experimental analysis of highly effective acetylcholinesterase inhibitors. 相似文献
43.
Anowar Tozri Moez Bejar Essebti Dhahri EL Kébir Hlil 《Central European Journal of Physics》2009,7(1):89-95
X-ray powder diffraction (XRD) and magnetic measurements were performed in order to investigate the effect of Na+ ion substitution for Ca2+ ions on the crystallographic structure, the character of magnetic ordering, and the effect of transition temperature in La0.7Ca0.3−x
Na
x
MnO3 manganites series (0 ⩽ × ⩽ 0.2). All samples crystallise in an orthorhombic structure with the Pnma space group. We have found a strong dependence of structural and magnetic properties on the cation-size disorder parameter
σ
2. The temperature dependence of magnetization of all samples obeys the Bloch T
3/2 law. The values of the spin wave constant at low temperature B increase with the increase of x and the Curie temperature decreases. It is concluded that the substitution of Ca by Na+ ions causes a decrease in total exchange integral Aof the samples.
相似文献
44.
Monte Carlo simulation has been used to study the magnetic properties and hysteresis loops of a single nanocube, consisting of a ferromagnetic core of spin- surrounded by a ferromagnetic shell of spin-1 with antiferromagnetic interface coupling. We find a number of characteristic phenomena. In particular, the effects of the shell coupling and the interface coupling on both the compensation temperature and the magnetization profiles are investigated. The effects of the interface coupling on the hysteresis loops are also examined. 相似文献
45.
JETP Letters - Pyridine has recently attracted significant attention because of its polymorphism and capability to form polymerized hydrocarbons at high pressures that have great technological... 相似文献
46.
Using Monte Carlo simulations with the Metropolis algorithm, we have studied the influence of crystal-field interaction on the critical behavior of magnetic spin-1 Ising film on a cubic lattice structure. The phase diagrams in the (kBTc/J,R=Js/J) plane are obtained for different values of the crystal-field interaction. We found that the special point Rsp(Rc), at which the critical temperature is independent of the film thickness N, is independent of the crystal-field interaction and that the system may exhibit a tricritical behavior. 相似文献
47.
48.
Crystallinity and fluorine substitution effects on the proton conductivity of porous hydroxyapatites
Porous calcium hydroxyapatite (p-HAp) was prepared by wet chemical methods. The poorly crystalline structure and the high surface specific area (235 m2/g) of this hydroxyapatite have effects on the variation of the electrical properties. Good linearity of logarithm of conductivity versus the relative humidity in the range from 19% to 88% (RH) was observed using the complex impedance spectroscopy. The proton conduction was affected by the relative humidity related to H2O adsorption on the material surfaces. The fluorine substitution in p-HAp also modifies the crystalline and the proton conduction properties. 相似文献
49.
Continuous approximations to the solution of systems of Volterraintegral equations of the first and second kinds are soughtby methods using spline functions of degree m, deficiency-(k1),i.e. in Cmk, and a fixed quadrature rule of degree p-1,p m-1. The resulting method is called an (m, k)-method. Thestability behaviour of the (m, 1)- and the (m, m)-method isstudied for arbitrarily finite m. Also studied is the stabilityof the (m, m-1)-method for second-kind systems. Convergenceresults and asymptotic formulae for the discretization errorare obtained. 相似文献
50.