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51.
Internal electrodes, adjacent to insulating walls at defined zeta potential, lead to a non-continuous potential distribution at the wall. Hence, simplified treatment appears problematic due to the singularity of the electrical field strength. To avoid this difficulty, we develop a hybrid model, which solves the electrical problem, including a resolution of the EDL, while the flow problem is solved in the fluid bulk only. We apply this hybrid model to investigate the position of internal electrodes with regard to their influence onto the flow field, driven by electroosmosis in a modular rectangular microchannel. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
52.
Summary: The barbituric acid moiety of the presented dyes shows multifunctional properties like acidochromism, solvatochromism, and adjustable hydrogen-bonding pattern for molecular recognition. Hydrogen-bonding ability, acidity and solvatochromic effects are studied for a series of N-alkyl substituted 5-(4-nitrophenyl)-barbiturates. Solvatochromism and metal ion complexation are also investigated using chromophoric thiobarbituric acid derivatives. 相似文献
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Pr4(SeO3)2(SeO4)F6 and NaSm(SeO3)(SeO4): Selenite‐Selenates of Rare Earth Elements Light green single crystals of Pr4(SeO3)2(SeO4)F6 have been obtained from the decomposition of Pr2(SeO4)3 in the presence of LiF in a gold ampoule. The monoclinic compound (C2/c, Z = 4, a = 2230.5(3), b = 710.54(9), c = 835.6(1) pm, β = 98.05(2)°, Rall = 0.0341) contains two crystallographically different Pr3+ ions. Pr(1)3+ is attached by six fluoride ions and two chelating SeO32– groups (CN = 10), Pr(2)3+ is surrounded by four fluoride ions, three monodentate SeO32– and two SeO42– groups. One of the latter acts as a chelating ligand, so the CN of Pr(2)3+ is 10. The selenite ions are themselves coordinated by five and the selenate ions by four Pr3+ ions. The coordination number of the F– ions is three and four, respectively. The linkage of the coordination polyhedra leads to cavities in the crystal structure which incorporate the lone pairs of the selenite ions. The reaction of Sm2(SeO4)3 and NaCl in gold ampoules yielded light yellow single crystals of NaSm(SeO3)(SeO4). The monoclinic compound (P21/c, Z = 4, a = 1066.9(2), b = 691.66(8), c = 825.88(9) pm, β = 91.00(2)°, Rall = 0.0530) contains tenfold oxygen coordinated Sm3+ ions. The oxygen atoms belong to five SeO32– and two SeO42– ions. Two of the SeO32– groups as well as one of the SeO42– groups act as a chelating ligand. The sodium ions are surrounded by five SeO42– ions and one SeO32– group. One of the selenate ions is attached chelating leading to a coordination number of seven. Each selenite group is coordinated by six (5 × Sm3+ and 1 × Na+), each selenate ion by seven cations (5 × Na+ and 2 × Sm3+). 相似文献
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Gd3(SeO3)4F: A Fluoride Selenite with μ3‐SeO32– and μ3‐F– Capped Gd3 Rings The decomposition of Gd2(SeO4)3 in the presence of LiF in sealed gold ampoules yields single crystals of Gd3(SeO3)4F (hexagonal, P63mc, Z = 2, a = 1044.3(1), b = 694.32(7) pm, Rall = 0.0286). In the crystal structure one SeO32– group and one F– ion cap a ring of three Gd atoms. Furthermore, the crystal structure is strongly influenced by the lone pairs of the SeO32– ions. 相似文献
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Pure anatase-TiO2 and/or titanate nanotubes, photochromic Ag loaded titanium dioxide nanotubes (TNTs) and AgCl loaded titanate nanotubes were synthesized by hydrothermal method. The pH value during the neutralization process plays a crucial role in controlling the morphology and composition of the nanotubes. All these nanotubes were confirmed by XRD, TEM, EDS and XPS analysis. Most of them have open ends with inner/outer diameters of 7/10 nm and several hundred nanometers in length. For photochromic behavior in the case of AgCl-titanate nanotubes, the red color can be clearly observed after irradiation by red light, while the yellow, green, blue ones displayed pale black after the corresponding irradiation. On the other hand, Ag loaded TNT sample exhibited multicolor photochromism corresponding to that of incident light. The photoreduction of silver halide to Ag particle in the case of loaded AgCl particles and a particle-plasmon-assisted electron transfer from Ag nanoparticles to TiO2 in the case of loaded Ag particles are considered to be responsible for this different behavior. 相似文献
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The ruthenium(II)-supported heteropolyanions [HXW7O28Ru(dmso)3]6-(X=P, 1; As, 2) are composed of a Ru(dmso)3 group attached to an unprecedented heptatungstate fragment via two Ru-O-W bonds and one Ru-O-X bond, which represents a fundamentally novel mode of Ru-coordination to a polyoxoanion framework. Multinuclear 183W, 31P, 13C, and 1H NMR studies indicate high stability of 1 and 2 in solution. 相似文献
59.
Thalictoside (I), a novel glycoside containing a nitro group, has been isolated from Thalictrum aquilegifolium and the structure has been established by chemical transformations, spectral analysis and synthesis. 相似文献
60.