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111.
An approach was developed for the synthesis of new multifunctional photosensitive liquid-crystalline copolymers of the acryl
series containing azobenzene, ionophoric, and mesogenic groups in the same macromolecule. The phase behavior of the copolymers
was studied. Most of these copolymers were demonstrated to form nematic mesophases. An increase in the concentration of crown-containing
groups to 26 mol.% leads to amorphization of the copolymers. The influence of complexation of the crown ether groups of the
copolymers with potassium perchlorate on the mesomorphic properties of the systems was investigated. A comparative study of
the photooptical properties of the copolymers in solution and thin films was performed.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2332–2242, December, 2007. 相似文献
112.
113.
利用偶氮聚电解质上的偶氮苯基团作为“探针”,研究了支化侧链偶氮聚电解质PMAPB6P-AA的偶氮生色团H-聚集动力学过程.研究发现,在不同THF/H2O配比情况下,H-聚集的速率有很大差别,THF比例越小,生色团发生H-聚集的速率越大,即偶氮聚电解质在溶剂体系中的疏水聚集对发生H-聚集有重要推动作用.通过测定偶氮聚电解质上的“孤立”生色团和H-聚集体的紫外光谱最大吸收值变化,表征了H-聚集过程的动力学,并分别用一级和二级动力学方程进行了拟合.结果表明,偶氮聚电解质的H-聚集过程具有二级动力学过程的特点. 相似文献
114.
115.
Natalia A. Nikonorova Nikolai N. Smirnov Ricardo Diaz‐Calleja Alexander V. Yakimansky 《Journal of Polymer Science.Polymer Physics》2008,46(14):1488-1496
Local forms of molecular mobility of comb‐like random copolymethacrylates, containing side‐chain nonlinear optical chromophores and amyl‐ or octafluoroamyl‐groups, are studied. In the glassy state, two relaxation processes are found, which are due to reorientation of terminal polar groups (γ2‐process) and rotation of chromophore groups about their long axes (β‐process). For octafluoroamyl‐containing copolymers, the γ2‐process is superposition of the two molecular motions due to reorientation of terminal chromophore groups and ? CF2H groups. The intensity and relaxation times in the range of the γ2‐process depend on the chemical structure and concentration of chromophores in a copolymer. For the β‐process, the molecular mobility weakly depends on the chromophore structure, being mainly determined by the relative lengths of the rigid chromophore and flexible side chains. On the global spectrum of depolarization current it was observed the γ1‐process due to reorientation of (CH2)n spacers between chromophore groups and copolymer backbone. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1488–1496, 2008 相似文献
116.
Melvina Leolukman Peerasak Paoprasert Ian Mandel Solimar J. Diaz David J. Mcgee Padma Gopalan 《Journal of polymer science. Part A, Polymer chemistry》2009,47(19):5017-5026
Linear‐dendritic block copolymer hosts were synthesized by end‐functionalizing poly(methylmethacrylate) with dendrons that acted as hydrogen‐bonding acceptors for nonlinear optical chromophores. Second harmonic generation experiments indicate that the d33 coefficients and maximum chromophore loading are increased in linear‐dendritic block copolymer hosts over comparable homopolymer hosts. Transmission electron microscopy shows 5–10 nm chromophore domains, confirming the effective spatial dispersion of the chromophores. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5017–5026, 2009 相似文献
117.
A practical method has been devised for the synthesis of previously unknown push-pull azochromophores with 5-nitropyridin-2-yl
acceptor moiety from 2-amino-5-nitro-1-oxypyridine.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 35–41, January, 2007. 相似文献
118.
Chinnusamy Saravanan Sengodan Senthil Palaninathan Kannan 《Journal of polymer science. Part A, Polymer chemistry》2008,46(23):7843-7860
Copolymer containing new thermally reversible click chemistry‐assisted triazole‐substituted azobenzene and fulgimide units in the pendant F‐co‐A was prepared by free‐radical solution addition polymerization technique. The F and A were also prepared for comparison. The DSC analysis of F indicates that the polymer possessing the C‐form of fulgimide unit exhibited higher Tm than that of E‐form of the same polymer and revealed that the C‐form of fulgimide unit in F is highly ordered. The cis‐trans back isomerization behavior of the click chemistry‐assisted triazole‐substituted azobenzene unit in film A has thermal irreversibility, while in F‐co‐A it exhibited thermal reversibility. The UV‐exposed film of F‐co‐A heated around Tg leads to cis‐trans back isomerization of azobenzene unit and thermally stable C‐form of fulgimide which retains its conjugated structure where both the photochromic units are converted into planar conformations and exhibit high fluorescence properties. The fluorescence maxima of C‐form in F‐co‐A red shifted compared with F , because the substituted triazole ring in the azobenzene unit stabilized the C‐form of fulgimide unit. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7843–7860, 2008 相似文献
119.
The Langmuir monolayer of carboxylic methyl ester Gemini surfactants with the azobenzene spacer, referred to as MCm(azo)MCm, was prepared and the π‐A isotherms were measured. The result revealed an orientational picture of the azobenzene spacer at the air/water interface. Before irradiation, the planar trans‐azobenzene group adopted an approximate configuration parallel to the interface and lay on the air/water interface. After UV‐light irradiation, the spacer became the twisted cis‐one. Because of the location of the polar headgroups at the air/water interface, the two phenyl rings were also forced to take a near‐parallel orientation with the interface to reduce the free energy. As a result, the spacer thin‐layer was "thickened", which caused an elevation in collapse pressure. 相似文献
120.
Fabian Hoffmann Dr. Anna-Lena Leistner Dr. Susanne Kirchner Prof. Dr. Burkhard Luy Dr. Claudia Muhle-Goll Dr. Zbigniew Pianowski 《European journal of organic chemistry》2023,26(20):e202300227
Photochromic supramolecular hydrogels are prospective materials for light-triggered drug release and bionanotechnology. Here we present a structural analysis of peptide-derived photochromic supramolecular hydrogels, which were physically loaded with a selection of biologically related compounds, using advanced techniques of nuclear magnetic resonance. The results enable detailed and correct understanding of the loading process and will allow for correct design of pharmacologically relevant systems for phototriggered drug delivery. 相似文献