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81.
A. A. M. Arafa 《Journal of statistical physics》2011,145(5):1357-1367
In this paper, Adomian’s decomposition method (ADM) has been used for solving time-fractional host-parasitoid system. The
derivatives are understood in the Caputo sense. The reason of using fractional order differential equations (FOD) is that
FOD are naturally related to systems with memory which exists in most biological systems. Also they are closely related to
fractals which are abundant in biological systems. Numerical example justifies the proposed scheme. 相似文献
82.
In this paper, generalized Euler method (GEM) and homotopy analysis method (HAM) are performed to solve the problem of the population dynamics of the human immunodeficiency type 1 virus (HIV-1). We introduce fractional orders to the model of HIV-1 whose components are plasma densities of uninfected CD4+ T-cells, the infected such cells and the free virus. The effect of the drug treatment of HIV-1 will be discussed in this paper. 相似文献
83.
84.
Mohamed A. Abdelgawad Mohammed Elmowafy Arafa Musa Mohammad M. Al-Sanea AbdElAziz A. Nayl Mohammed M. Ghoneim Yasmine M. Ahmed Hossam M. Hassan Asmaa M. AboulMagd Heba F. Salem Nada S. Abdelwahab 《Molecules (Basel, Switzerland)》2022,27(2)
Foods with medical value have been proven to be beneficial, and they are extensively employed since they integrate two essential elements: food and medication. Accordingly, diabetic patients can benefit from papaya because the fruit is low in sugar and high in antioxidants. An RP-HPLC method was designed for studying the pharmacokinetics of metformin (MET) when concurrently administered with papaya extract. A mobile phase of 0.5 mM of KH2PO4 solution and methanol (65:35, v/v), pH = 5 ± 0.2 using aqueous phosphoric acid and NaOH, and guaifenesin (GUF) were used as an internal standard. To perform non-compartmental pharmacokinetic analysis, the Pharmacokinetic program (PK Solver) was used. The method’s greenness was analyzed using two tools: the Analytical GREEnness calculator and the RGB additive color model. Taking papaya with MET improved the rate of absorption substantially (time for reaching maximum concentration (Tmax) significantly decreased by 75% while maximum plasma concentration (Cmax) increased by 7.33%). The extent of absorption reduced by 22.90%. Furthermore, the amount of medication distributed increased (30.83 L for MET concurrently used with papaya extract versus 24.25 L for MET used alone) and the clearance rate rose by roughly 13.50%. The results of the greenness assessment indicated that the method is environmentally friendly. Taking papaya with MET changed the pharmacokinetics of the drug dramatically. Hence, this combination will be particularly effective in maintaining quick blood glucose control. 相似文献
85.
A technique based on the optical density (D) measurement of the etched track is useful for charged particles spectroscopy using SSNTD. It was shown that the stopping power of alpha particles in CR-39 is proportional to D. We measured the optical density and derived an expression to estimate the range of alpha particles in CR-39 detector as a function of the bulk etching rate and etching time. The relation between the etching time, track parameters (depth, radius) and D for different alpha particles energy and etching conditions were studied. A relation describing D as a function of track size is proposed. 相似文献
86.
Alberto PlazaGiuseppe Bifulco Arafa I. HamedCosimo Pizza Sonia Piacente 《Tetrahedron letters》2003,44(47):8553-8558
Argeloside A and B, two novel 14,15-secopregnane glycosides characterized by the presence of two hemiketal functions involved in two five-membered rings, were isolated from Solenostemma argel fruits. Their structures have been established by ESIMS and NMR experiments. In particular the relative configuration of the molecules has been defined by combining the available NMR data with quantum chemical calculations of the geometries and 13C chemical shifts. 相似文献
87.
Ali Ali Arafa Fathi Sultan Ahmed Sultan Ibrahim Sayed Shafie 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1956,7(1):75-80
Zusammenfassung Ein Hitzdrahtmanometer bildet, mit einem Thermistor in eine Wheatstone-Anordnung geschaltet, ein Thermistor-Pirani-Messgerät hoher Empfindlichkeit, das in einem weiten Gebiet eine lineare Druck-Strom-Abhängigkeit zeigt. Dabei wird von der verstärkenden Wirkung der negativen Widerstandcharakteristik eines Thermistors Gebrauch gemacht, um die von winzigen Druckänderungen herrührenden kleinen Widerstandvariationen zu verstärken. 相似文献
88.
Eman Turky Shamkhy Isam Hussain T. Al-Karkhi Emad A. Jaffar Al-Mulla 《Research on Chemical Intermediates》2013,39(6):2463-2471
A new Schiff base N-[(E)-(2-hydroxyphenyl)methylidene]-N’-[(Z)-(2-hydroxyphenyl)methylidene]ethanebis(thioamide) (LC) containing sulfur, nitrogen, and oxygen atoms has been synthesized by condensation of ethanebis(thioamide) with 2-hydroxybenzaldehyde. Metal complexes were synthesized by reaction of the new ligand with copper(II) and cobalt(II) as nitrate salts and with rhodium(III) as chloride salt, using hot absolute ethanol as solvent. All the new compounds were characterized by use of different physicochemical techniques including UV–visible spectroscopy, magnetic susceptibility, IR spectroscopy, molar conductance, and determination of metal content. It is proposed the paramagnetic copper and cobalt complexes adopt octahedral geometry whereas the diamagnetic rhodium complex has octahedral geometry. 相似文献
89.
Isam M. Arafa Mohammad F. Gharaibeh Mazin Shatnawi Javier Perez 《Journal of Non》2012,358(6-7):1044-1051
Three hybrid materials composed of planar s-triazine rings and polyhedral silica (SiO2), phenylsilsesquioxane (PhSiO1.5) and diphenylsiloxane (Ph2SiO) building blocks were investigated by differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS) techniques. These measurements revealed that the geometrically dissimilar components were fully integrated into intact glassy hybrid structures. Their DSC thermograms showed that these hybrids are thermally stable below 350 °C with moderate glass transition temperatures (Tg) of 56–110 °C consistent with the increasing structural connectivity of the silicone component. The SAXS data was analyzed to obtain different structural information using Porod, Guinier and Kratky approximations. The general features of each of the SAXS profiles of these hybrids are very similar to those of polyphenylsilsesquioxane (PPhSQ). The SAXS profiles reveal that these hybrids can be described as nano-scale primary particles that are self-organized in macromolecular ensembles to form extended unfolded textures of varying scattering lengths (91–168 Å). The obtained hybrid particles adopt either 3-D bulk fractals with open structures or 2-D surface fractals with dense cores. The short interfacial thickness (< 3 Å) and the low thermal fluctuation parameters strongly suggest that these particles are held together by substantial cohesion forces. 相似文献
90.
In this paper, the homotopy analysis method (HAM) has been employed to obtain analytical solution of a two reaction–diffusion systems of fractional order (fractional Schnakenberg systems) which has been modeling morphogen systems in developmental biology. Different from all other analytic methods, HAM provides us with a simple way to adjust and control the convergence region of solution series by choosing proper values for auxiliary parameter h. The fractional derivative is described in the Caputo sense. The reason of using fractional order differential equations (FOD) is that FOD are naturally related to systems with memory which exists in most biological systems. Also they are closely related to fractals which are abundant in biological systems. The results derived of the fractional system are of a more general nature. Respectively, solutions of FOD spread at a faster rate than the classical differential equations, and may exhibit asymmetry. However, the fundamental solutions of these equations still exhibit useful scaling properties that make them attractive for applications. 相似文献