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51.
Wanda?M.?Aylward Peter?G.?PickupEmail author 《Journal of Solid State Electrochemistry》2004,8(10):742-747
Sulfonated ormosil hydrogels (~80% water) were prepared using tetramethyl orthosilicate as a silica precursor and 2(4-chlorosulfonylphenyl)ethyltrichlorosilane to provide sulfonate functionality for ion-exchange and ion conductivity. Ruthenium(III) hexamine was used as a redox probe in electrochemical studies performed on porous carbon fibre paper electrodes impregnated with the gel. The gel-modified electrodes extracted Ru(NH3)63+ from solutions in 0.1 M CF3CO2Na(aq) with a partition coefficient of ~36, and with ~100% of the sulfonate sites being accessible for ion exchange. The Ru(NH3)63+/2+ couple exhibited reversible and facile electrochemistry in the gel, with a Ru(NH3)62+ diffusion coefficient of 4.9×10–8 cm2 s–1 determined by chronoamperometry. This is an order of magnitude higher than the mobility of this complex in Nafion. The hydrogel-modified electrodes were stable for days, and could be repeatedly loaded with Ru(NH3)63+.Special Issue to celebrate the 70th birthday of Professor Zbigniew Galus 相似文献
52.
Zurowska B Mroziński J Julve M Lloret F Maslejova A Sawka-Dobrowolska W 《Inorganic chemistry》2002,41(7):1771-1777
Thiocyanatonickel(II) and thiocyanatocobalt(II) complexes of the composition Ni(NCS)(2)(HIm)(2) (1) and Co(NCS)(2)(HIm)(2) (2), where HIm = imidazole, were prepared and studied. In particular, the crystal structure of Ni(NCS)(2)(HIm)(2) was determined by X-ray methods. This compound crystallizes in the monoclinic system, space group P2(1)/n, with a = 7.720(1) A, b = 5.557(1) A, c = 13.774(3) A, beta = 102.54(3) degrees, and Z = 2. Its structure consists of a one-dimensional polymeric chain in which nickel(II) ions are bridged by two thiocyanate groups bonding in an end-to-end fashion in a trans arrangement. The Ni...Ni distance is 5.557(1) A. The crystal packing is determined by the intermolecular hydrogen bonds and ring-stacking interactions. From their X-ray powder-diffraction patterns and IR spectra, the complexes 1 and 2 were found to be mutually isomorphous. The coordination compounds were identified and characterized using elemental analysis, magnetic measurements, and infrared and ligand-field spectra. Both complexes are first examples of ferromagnetically coupled one-dimensional polymeric compounds with double end-to-end thiocyanate bridges. The magnetic properties of the title compounds were investigated over the 1.9-290 K temperature range. The compounds exhibit long-range magnetic ordering with T(c) equal to 5.0 and 5.5 K for 1 and 2, respectively. Their isothermal magnetization was also studied. The magnetostructural properties of the nickel(II) compound obtained are discussed and compared to those of other double end-to-end thiocyanate-bridged nickel(II) complexes. 相似文献
53.
Summary The 1,3-dipolar cycloaddition reactions of 4,6-diazaphenanthrene 6-phenacylide formed in situ from the appropriate quaternary bromide in basic medium were investigated; as dipolarophiles acrylonitrile, ethyl acrylate,n-butyl acrylate and diethyl maleate were used.
1,3-Dipolare Cycloadditionsreaktionen von 4,6-Diazaphenanthren-6-phenacylid
Zusammenfassung Es wurden die 1,3-dipolaren Cycloadditionen von 4,6-Diazaphenanthren-6-phenacylid untersucht, welches in situ aus dem entsprechenden quaternären Bromid in Gegenwart von Alkali dargestellt wurde. Als Dipolarophile wurden Acrylnitril, Ethylacrylat,n-Buthylacrylat und Diethylmaleat eingesetzt.相似文献
54.
55.
Spectroscopic investigations have been undertaken on the effects of lanthanide ions on the spectrum of the anticancer agent, daunomycin. The visible spectral perturbations due to the metal ions resulted in hypochromic effects in the 480 nm region and in shifts towards longer wavelength. The different metal ions investigated did not give any significant difference in the, spectral character. Data analysis according to the methods of molar ratio, continuous variation and graphical approaches based on simplex matrix theory indicated the presence of predominantly a ML2 species at metal to ligand ratios, less than one. Data also suggested the presence of ML and ML3 as well. 相似文献
56.
Małgorzata T. Kaczmarek Maciej Kubicki Wanda Radecka-Paryzek 《Structural chemistry》2010,21(4):779-786
The self-assembled formation of dinuclear lanthanide salicylaldimines is proved by the X-ray diffraction analysis of europium
and gadolinium nitrate complexes containing N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine (H2L). The [Eu2(H2L)2(μ-H2L)2(NO3)6] complex, isostructural with the gadolinium complex, displays nine-coordinate distorted tricapped trigonal prism geometry
with a different coordination mode of four undeprotonated salicylaldimines, which act as terminal monodentate and μ-bridging
ditopic ligands using exclusively the oxygens as donor atoms with the nitrogen atoms not being involved in the coordination
environment. These complexes along with similar lanthanum, erbium, thulium, and lutetium complexes were prepared in situ in
a one-step metal promoted condensation reaction between salicylaldehyde and 4-methyl-1,3-phenylenediamine in the presence
of lanthanide nitrates. They were isolated and characterized by microanalysis and spectroscopic (IR, ESI–MS, UV–Vis, and 1H NMR) data with reference to the preformed N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine, which was obtained separately and structurally determined by single crystal
X-ray analysis. 相似文献
57.
Hanna B. Szczeniak Violetta Patroniak Wanda Radecka‐Paryzek Maciej Kubicki 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(8):o371-o373
The crystal structure of the title compound, C7H24N44+·3ClO4−·Cl−, is mainly determined by electrostatic interactions between the charged species and a number of relatively weak N—H...O and N—H...Cl− hydrogen bonds. The rich structure of such hydrogen bonds creates infinite layers of ions extending along the [001] direction. The tetracation has the gttttttg conformation, similar to the single previously known example of such a cation. The presence of two different anions can be connected with the undecided competition between them, and some of the packing advantages of such a situation are found in the crystal structure. 相似文献
58.
Mikołajczyk M Krysiak JA Midura WH Wieczorek MW Rózycka-Sokołowska E 《The Journal of organic chemistry》2006,71(23):8818-8823
A new one-pot synthesis of heterocyclic and carbocyclic vinyl sulfoxides has been developed which involves reaction of alpha-phosphorylvinyl sulfoxides with carbonyl compounds bearing oxygen, nitrogen, and carbon nucleophilic centers. Use of optically active alpha-phosphorylvinyl p-tolyl sulfoxides in this tandem Michael addition/Horner olefination reaction leads to the corresponding optically active cyclic sulfoxides. In this way, a variety of optically active chromene, pyrrolizine, chinoline, and cyclopentene sulfoxides have been efficiently prepared. 相似文献
59.
60.
Yuelie Lu Tingjian Xiang Charles Bernard Liang Huang Aaron Siegmund Gary Guo Wanda Tormos Kevin Koch Laurence E. Burgess Prabha Ibrahim 《Tetrahedron》2006,62(50):11714-11723
A concise, scaleable synthesis of building block 10 for p38 kinase inhibitor B is described. The key step is the one-pot construction of 5-aryl-3-methyl-2-methylsulfanyl-6-pyridin-4-yl-3H-pyrimidin-4-one 4 from arylacetic acid ethyl ester 1. Subsequent hydrolysis of the thiomethyl group to the hydroxy group and chlorination provided the key intermediate, 2-chloro-3-methyl-6-pyridin-4-yl-5-aryl-3H-pyrimidin-4-one 10. This class of reactive building blocks enabled the rapid evaluation of a variety of side chains at the 2-position of the pyrimidinone in SAR studies of inhibitors of p38 MAP kinase. 相似文献