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21.
Lahcen Hssaini Francisca Hernandez Manuel Viuda-Martos Jamal Charafi Rachid Razouk Karim Houmanat Rachida Ouaabou Said Ennahli Driss Elothmani Ilham Hmid Marie Laure Fauconnier Hafida Hanine 《Molecules (Basel, Switzerland)》2021,26(9)
In the present study, chromatic coordinates, phenolic acids, flavonoids and antioxidant capacity assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS) and lipid peroxidation inhibition capacity (LPIC) essays and their relative IC50 were investigated in 25 fig cultivars growing in Morocco. The aims of this study were to determine (i) the variation in these compounds among light and dark-colored cultivars, (ii) their partitioning between fruit peel and pulp and (iii) to display network connections among these variables. Twelve phenolic compounds (PCs) were isolated in peel extract versus eight in pulp samples. Anthocyanins, mainly cyanidin-3,5-diglucoside and cyanidin-3-O-rutinoside, were the predominant compounds in peels, where the mean concentrations were 75.90 ± 18.76 and 77.97 ± 18.95 µg/g dw, respectively. On the other hand, (−)-epicatechin and cyanidin-3-O-rutinoside were the major compounds in the pulp extracts, where the mean values were 5.23 ± 4.03 and 9.01 ± 5.67 µg/g dw, respectively. A two-dimensional hierarchically clustered heatmap was applied to the dataset to explore correlations in the dataset and similarities between cultivars, without dimensionality reduction. Results showed that anthocyanins, particularly pelargonidin-3-O-rutinoside, cyanidin-3,5-diglucoside and cyanidin-3-O-rutinoside, were the main contributors to the peels’ free radical scavenging capacity. This capacity was particularly higher in the peel of dark-colored figs compared to the fruit pulp. The local cultivar “INRA 1301” showed the most promising phenolic profile due to its very high levels of almost all detected PCs, especially (−)-epicatechin, quercetin-3-O-rutinoside, quercetin-3-O-glucoside, cyanidine-3,5-diglucoside, cyanidine-3-O-rutinoside and pelargonidin-3-O-rutinoside (54.66, 141.08, 35.48, 494.08, 478.66, 12.56 µg/g dw, respectively). Having the darkest figs in the collection (L* = 25.72, c* = 22.09 and h° = 20.99), this cultivar has also combined promising IC50 values, which were of 19.85, 40.58 and 124.78 µg/mL for DPPH, ABTS and LPIC essays, respectively. 相似文献
22.
Study of a cysteine derivative as a corrosion inhibitor for carbon steel in phosphoric acid solution
H. Zarrok A. Zarrouk R. Salghi B. Hammouti M. Elbakri M. Ebn Touhami F. Bentiss H. Oudda 《Research on Chemical Intermediates》2014,40(2):801-815
Inhibition of corrosion of carbon steel in phosphoric acid solution by use of l-cysteine methyl ester hydrochloride has been investigated by measurement of weight loss and use of electrochemical methods. The efficiency of inhibition was increased by increasing the concentration of the inhibitor and reduced by increasing the temperature. Polarization studies revealed that this compound behaves as mixed-type inhibitor. Electrochemical impedance spectroscopy showed that dissolution of the steel occurs as a result of charge-transfer. Adsorption of the inhibitor obeyed the Langmuir adsorption isotherm. Kinetic and thermodynamic data were calculated and are discussed. 相似文献
23.
Chi‐Cheung Su Meinan He Jiayan Shi Rachid Amine Jian Zhang Khalil Amine 《Angewandte Chemie (International ed. in English)》2020,59(41):18229-18233
Despite the exceptionally high energy density of lithium metal anodes, the practical application of lithium‐metal batteries (LMBs) is still impeded by the instability of the interphase between the lithium metal and the electrolyte. To formulate a functional electrolyte system that can stabilize the lithium‐metal anode, the solvation behavior of the solvent molecules must be understood because the electrochemical properties of a solvent can be heavily influenced by its solvation status. We unambiguously demonstrated the solvation rule for the solid‐electrolyte interphase (SEI) enabler in an electrolyte system. In this study, fluoroethylene carbonate was used as the SEI enabler due to its ability to form a robust SEI on the lithium metal surface, allowing relatively stable LMB cycling. The results revealed that the solvation number of fluoroethylene carbonate must be ≥1 to ensure the formation of a stable SEI in which the sacrificial reduction of the SEI enabler subsequently leads to the stable cycling of LMBs. 相似文献
24.
Numerical modeling of multiphase flow generally requires a special procedure at the solid wall in order to be consistent with Young's law for static contact angles. The standard approach in the lattice Boltzmann method, which consists of imposing fictive densities at the solid lattice sites, is shown to be deficient for this task. Indeed, fictive mass transfer along the boundary could happen and potentially spoil the numerical results. In particular, when the contact angle is less than 90 degrees, the deficiencies of the standard model are major. Various videos that demonstrate this behavior are provided (Supporting Information). A new approach is proposed and consists of directly imposing the contact angle at the boundaries in much the same way as Dirichlet boundary conditions are generally imposed. The proposed method is able to retrieve analytical solutions for static contact angles in the case of straight and curved boundaries even when variable density and viscosity ratios between the phases are considered. Although the proposed wetting boundary condition is shown to significantly improve the numerical results for one particular class of lattice Boltzmann model, it is believed that other lattice Boltzmann multiphase schemes could also benefit from the underlying ideas of the proposed method. The proposed algorithm is two‐dimensional, and the D2Q9 lattice is used. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
25.
H. Eleuch N. Rachid 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,57(2):259-264
We study the photon statistics of the field emitted from a semiconductor microcavity containing a quantum well in the non-linear
regime. The q-deformed boson concept (quon) allows us to derive an analytical expression of the autocorrelation function in
non-resonant pumping. The dependence of the dynamical behavior of the autocorrelation function on the q deformation parameter
is discussed. 相似文献
26.
Fadela Iftene Ghislain David Bernard Boutevin Rémi Auvergne Ali Alaaeddine Rachid Meghabar 《Journal of polymer science. Part A, Polymer chemistry》2012,50(12):2432-2443
Three new vinyl ether monomers containing phosphonate moieties were synthesized from transetherification reaction. We showed that the yield was dependent on the spacer length between the vinyl oxy group and the phosphonate moieties: when the spacer is a single methylene side reaction may occur, leading to the formation of acetal compounds. Free‐radical copolymerizations of phosphonate‐containing vinyl ether monomers with maleic anhydride were carried out, leading to alternated copolymers of rather low molecular weights (from 1000 to 7000 g/mol). Both gel permeation chromatography and 31P NMR analyses enhanced possible intramolecular transfer reactions occurring from the phosphonate moieties. Kinetic investigation showed that the electron‐withdrawing character of the phosphonate moieties tends to decrease the rate of copolymerization. Nevertheless, almost complete monomers conversion was reached after 30 min of reaction with dimethyl vinyloxyethylphosphonate (VEC2PMe). Then, radical copolymerization of VEC2PMe with a series of electron‐accepting monomers, that is, dibutyl maleate, dibutylitaconate, itaconic anhydride, butyl maleimide, and methyl maleimide, led to a series of alternated copolymers. From kinetic investigation, we showed that the higher the electron‐accepting effect, the faster the vinyl ether consumption and the higher the molecular weights. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
27.
Falck JR Barma DK Baati R Mioskowski C 《Angewandte Chemie (International ed. in English)》2001,40(7):1281-1283
28.
29.
Zaid Faska Aicha Bellioua Mohamed Bouklah Lhou Majidi Rachid Fihi Abdelahamid Bouyanzer Belkheir Hammouti 《Monatshefte für Chemie / Chemical Monthly》2008,139(12):1417-1422
The inhibitive action of pulegone and pulegone oxide toward acid corrosion of steel in molar hydrochloric acid was studied
by weight loss measurements, potentiodynamic polarization, and impedance spectroscopy (EIS) methods. The pulegone is extracted
starting from oil of Pennyroyal Mint (Mentha pulegium). The natural compound was found to delay the corrosion rate. The pulegone oxide is prepared by oxidation of pulegone. The
inhibition efficiency was found to increase with the inhibitor content to attain 81 and 75% at 5 g dm−3 for pulegone and pulegone oxide. The increase in temperature leads to an increase in the inhibition efficiency of the natural
compared.
Correspondence: Belkheir Hammouti, Laboratoire de chimie Appliquée & Environnement, Faculté des Sciences, B.P. 717, 60000
Oujda, Morocco. 相似文献
30.
Antonio Herrera Nazario Martín Rachid Chioua Ángel Sánchez-Vázquez John Almy 《Tetrahedron》2009,65(8):1697-2715
Two alternative methods for the preparation of new pyrimidine Diels-Alder cycloadducts from the readily available 2,4-bis(methylsulfanyl)-5,6-dihydrocyclobuta[d]pyrimidine are presented. In the first method, the in situ generated pyrimidine ortho-quinodimethane reacts with various dienophiles to form the respective cycloadducts bearing two methylthio groups, which can be easily replaced by other functional groups. In the second method, one or both of the methylsulfanyl groups of the starting pyrimidine are replaced first and the resulting functionalized pyrimidines are able to undergo Diels-Alder cyclization with different dienophiles to form pyrimidine cycloadducts. These alternative synthetic strategies provide access to a wide variety of pyrimidine cycloadducts with a different substitution pattern on the pyrimidine ring. Yield data indicate that the electronic nature of the functional groups strongly influence the efficiency of the cycloaddition reaction. 相似文献