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51.
Marwa A. El-Ghobashy Ibrahim A. Salem Sahar R. Abdel-Rahman Mohamed A. Salem 《国际化学动力学杂志》2023,55(1):25-38
The heterogeneous catalytic oxidation of Chromotrope 2B (C2B) dye with H2O2 and the aluminum oxide hydroxide (AlOOH) modified with ammonia complexes of CuII, CoII, NiII, and CrIII (AlOOH/[Mn+(amm)m]) as catalysts were studied. The AlOOH/[CuII(amm)4] is the most efficient catalyst and therefore it was chosen as the potential catalyst for the oxidative degradation of C2B in an aqueous solution. The AlOOH/[CuII(amm)4] was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM), techniques. The rate of reaction was dependent on the type of the metal complex supported on the AlOOH, initial concentration of the dye and H2O2, catalyst dose, pH, the concentration of NaCl, and temperature. The catalytic activity of the AlOOH/[Mn+(amm)m] according to the kind of metal ion decreased in the order: CuII > CoII > CrIII > NiII. Other catalysts consisting of the AlOOH supported with CuII complexed with ethylenediamine, ethanolamine, 1,3 propanediamine, and 1,4 butanediamine, (AlOOH/[CuII(amine)m]), were also investigated. The activity of the (AlOOH/[CuII(amine)m]) as catalyst according to the type of ligand followed the order: 1,4 butanediamine > 1,3 propanediamine > ethanolamine > ethylenediamine > ammonia. The reaction rate increased with increasing the catalyst dose, concentration of H2O2, C2B, and NaCl, pH, and temperature. Since the reusability results for the AlOOH/[CuII(amm)4] revealed good stability over seven cycles, it can thus be considered a promising and cost-effective catalyst for the removal of harmful dyes from wastewater. 相似文献
52.
Lauren M. Gehman Kalyan V. Vasudevan Rachel R. Butorac Salem S. Al-Deyab Alan H. Cowley 《Journal of chemical crystallography》2011,41(7):998-1001
Abstract
The coordination of decamethyleuropocene to a “clamshell” 1,2-bis(imino)acenaphthene (BIAN) ligand is accompanied by a one-electron redox process. The crystal structure of the Eu3+ product has been determined. The complex crystallizes in the triclinic space group P-1, with a = 12.065(2), b = 15.391(3), c = 17.266(4) ?, α = 73.71, β = 73.93(3), γ = 81.40(3)°, V = 2948.3(10) ?3 and Z = 2. The pyridine moiety of the clamshell ligand is not coordinated to the Eu3+ center. 相似文献53.
We present pseudo-potential calculations of geometrical structures of stable isomers of LiAr
n
clusters with both an electronic ground state and excited states of the lithium atom. The Li atom is perturbed by argon atoms
in LiAr
n
clusters. Its electronic structure obtained as the eigenfunctions of a single-electron operator describing the electron in
the field of a Li+Ar
n
core, the Li+ and Ar atoms are replaced by pseudo-potentials. These pseudo-potentials include core-polarization operators to account for
the polarization and correlation of the inert core with the valence Lithium electron [J Chem Phys 116, 1839 1]. The geometry optimization of the ground and excited states of LiAr
n
(n = 1–12) clusters is carried out via the Basin-Hopping method of Wales et al. [J Phys Chem 101, 5111 2; J Chem Phys 285, 1368 3]. The geometries of the ground and ionic states of LiAr
n
clusters were used to determine the energy of the high excited states of the neutral LiAr
n
clusters. The variation of the excited state energies of LiAr
n
clusters as a function of the number of argon atoms shows an approximate Rydberg character, corresponding to the picture
of an excited electron surrounding an ionic cluster core, is already reached for the 3s state. The result of optical transitions calculations shows that the absorption spectral features are sensitive to isomer
structure. It is clearly the case for transitions close to the 2p levels of Li which are distorted by the cluster environment. 相似文献
54.
Yussri Salem 《Surface and interface analysis : SIA》2022,54(7):775-785
The current study aims to characterize a heavily corroded bronze statue from Pharaonic Egypt, in terms of the morphology and mechanism of corrosion. The characterization was carried out by a combination of methods, including the scanning electron microscope equipped with energy dispersive X-ray spectroscopy (SEM–EDS), USB digital microscope, X-ray micro-diffraction, and Raman micro-spectroscopy. Insights into the morphology and corrosion mechanisms of two corrosion stages are presented. Specifically, the metallic-wall layer was first converted into grayish-brown corrosion mottled with green and gray spots in the central part, in which a greenish-white corrosion phase was formed in the second stage. The EDS analysis of the greenish-white phase revealed the predominance of tin, copper, oxygen, and carbon and a low chlorine content. The greenish-white phase consisted of four corrosion products: romarchite, cassiterite, malachite, and a small amount of atacamite. The morphology developed upon corrosion was attributed to the selective dissolution and depletion of copper in the central layer, internal oxidation of tin, and conversion of cuprite into malachite. Moreover, the usual bronze corrosion products were formed as a superficial layer on the statue. 相似文献
55.
Sherif A. Tawfik S.M. El-Sheikh N.M. Salem 《Physica E: Low-dimensional Systems and Nanostructures》2011,44(1):111-114
We investigate the field emission properties of nitrogenated and boronated carbon nanotubes using time-dependent density functional theory, where the wave function propagation is performed using the Crank–Nicholson algorithm. We extract the current–voltage characteristics of the emitted electrons from nanotubes with different doping configurations. We found that boron doping alone either impedes, or slightly enhances, field emission. Nitrogen generally enhances the emission current, and the current is sensitive to the location of the nitrogen dopant in the nanotube. Doping with both nitrogen and boron will generally enhance emission, and the closer the nitrogen dopant is to the tip, the higher is the emitted current. The emitted charge cloud from nitrogen-doped carbon nanotubes, however, diffuse more than that from pristine ones, our simulations show the emergence of a branching structure from the charge cloud, which suggests that nitrogenated carbon nanotubes are less convenient for use in precision beam applications. 相似文献
56.
Mahmoud Farouk Salman A. Alrokayan Ahamad Imran Khalid M. Abu-Salah Mohamed Ghazzali Khalid A. Al-Farhan Salem El-Gohary Mamdouh Adly 《Chemical Papers》2013,67(2):229-235
3-Substituted quinazoline-2,4(1H,3H)-dione and 2,3-di-substituted quinazolineone derivatives attract considerable interest due to their pharmacological properties. In this paper, we report the synthesis of N-substituted-3-nitrophthalimide derivatives II?CIII, the reactions of phthalimide III with amines, hydrazines, and amino acid derivatives to synthesise a small library of 3-substituted-5-nitroquinazoline-2,4(1H,3H)-diones IV?CXIV and 2,3-di-substituted-6-nitro-quinazolineones XVIII?CXIX. 相似文献
57.
Hussein A.H. Salem 《Mathematical and Computer Modelling》2009,49(3-4):829-834
In this paper, we investigate the solvability of a multi-term fractional differential equation in a reflexive Banach space relative to weak topology. A particular case of our main result is treated. 相似文献
58.
Quantitative determination of tetroxoprim and sulphadiazine in serum and urine was performed using reversed phase high performance liquid chromatography. Protein precipitation using 10% perchloric acid was utilized for purification of serum samples while urine samples were diluted prior to analysis. The mobile phase consisted of triethylammonium acetate buffer (85%), acetonitrile (12%) and methanol (3%), with a final pH of 4.2. The eluent was monitored at 280 nm. Benzoic acid was used as an internal standard. Standardization, validation and application of the method is described. 相似文献
59.
The present work is devoted to the experimental and numerical study ofthe interaction of a turbulent plane jet with a rectangular cavity.Several flow regimes have been found to occur: the non-oscillationregime, the stable oscillation regime and an unstable oscillationregime. The first two regimes have been particularly considered. Theexperimental study has been carried out using hot wire anemometry andsome visualisations. The numerical predictions based on statisticalmodelling have been made using on the one hand the standard k– model and on the other hand a two-scales split spectrum model. The structuralproperties of the flow have been described for the different situations.For the oscillatory regime, a parametrical study allowed to determinethe influence of the jet exit location and the Reynolds number on thefrequency of the jet flapping. The one point closures have been able topredict the oscillatory regime, and in particular the two-scales modelled to improved results because better account is taken of lag effectsin unsteady non-equilibrium situations. 相似文献
60.
The qualitative uncertainty principle proved by Benedicks asserts that f and its Fourier transform \(\hat f\) cannot both concentrated in subsets of finite Lebesgue measure. In this paper we obtain some uncertainty principles concerning sets of finite measure in the Jacobi setting. 相似文献