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71.
72.
Fu Z Ochsner MA de Hoog HP Tomczak N Nallani M 《Chemical communications (Cambridge, England)》2011,47(10):2862-2864
Multicompartmentalized polymersomes are formed using block co-polymers PMOXA-PDMS-PMOXA and PS-PIAT, and are subsequently proven to be capable of selective encapsulation of biomacromolecules. This architecture mimics the compartmentalization found in cells and may serve as a simple, albeit robust, model system. 相似文献
73.
Aminopeptidases catalyze the cleavage of specific amino acids from the amino terminus of protein or peptide substrates. A
proline-specific aminopeptidase was purified to homogeneity from the culture-free extract of Streptomyces lavendulae ATCC 14162 in sequential steps comprising ammonium sulfate precipitation, ultra-filtration, and column chromatography on
Q-sepharose and Sephadex G-100. The purified protein showed approximately 60 kDa in SDS-PAGE and was optimally active at pH
6.5 and 40 °C. Kinetic studies showed a K
m and V
max of 0.23 mM and 0.087 μmol/min, respectively, using Pro-p-NA, the substrate with maximum specificity. Enzyme activity was inhibited by PMSF and ions like Zn2+, Co2+, and Ni2+. However, unlike other aminopeptidases, the activity was enhanced in the presence of DTT, 1,10-phenanthroline, EDTA, amastatin,
and bestatin. Ions like Ca2+, Mg2+, and Mn2+ also enhanced the activity. 相似文献
74.
Ponnusamy Shanmugam Suchithra Madhavan Kodirajan Selvakumar Vadivel Vaithiyanathan Baby Viswambharan 《Tetrahedron letters》2009,50(19):2213-1593
A one-pot synthesis of mono- and bis-Morita-Baylis-Hillman adducts of 1,1′-ferrocenedialdehyde has been achieved. These adducts undergo a facile and efficient stereoselective isomerization with a number of saturated, unsaturated, aromatic alcohols, phenols and thiophenol with a montmorillonite K10 clay catalyst to afford highly functionalized trisubstituted alkene derivatives of ferrocene. The synthetic utility of isomerized derivatives has been demonstrated by a ferrocene appended novel macrocycle synthesis, a ferrocenyl bis-triazole synthesis and an evaluation of the liquid crystalline property of a cholesterol derivative of ferrocene. 相似文献
75.
P. Praveen Kumar S. Tamilselvan Victor Antony Raj J. Madhavan 《Optics Communications》2008,281(10):2989-2995
Single crystals of pure, Cu2+and Mg2+ doped l-histidine acetate (LHA) were grown successfully by slow evaporation technique. The X-ray diffraction (XRD) studies were carried out for the pure and doped grown crystals. Absorption of these grown crystals was analyzed using UV-vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 nm to 1500 nm. The pure and doped crystals are characterized by Fourier transform Raman (FT-Raman), thermal and photoconductivity studies. Vickers microhardness tests were carried out for the pure and doped crystals and the mechanical strengths were found. The dielectric constant and the dielectric loss with frequency were also studied. 相似文献
76.
Periodic intensity variation with temperature of SRS in liquids, with fine periods of the order of 1–2°C at room temperature, have been observed by us and other workers. We report our experimental results and also offer an explanation for the thermospectrum based on the non-linear interactions between the laser and Raman waves in the liquid media. Calculated periods based on this hypothesis agree fairly well with our experimental results and those of other workers as well. 相似文献
77.
Summary The utility of controlled potential coulometry for the accurate estimation of ferrocyanides has been established. The method is accurate and rapid and in both these aspects it compares favourably with other methods of estimation. The details for coulometric method have been worked out and the extent of interference of other radicals like chloride has been investigated. 相似文献
78.
79.
80.
Mahmud Abu-Odeh Dr. Katharina Bleher Neethinathan Johnee Britto Prof. Dr. Peter Comba Dr. Michael Gast Prof. Madhavan Jaccob Dr. Marion Kerscher Dr. Saskia Krieg Marius Kurth 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(44):11377-11390
The nonheme iron(IV)-oxido complex trans-N3-[(L1)FeIV=O(Cl)]+, where L1 is a derivative of the tetradentate bispidine 2,4-di(pyridine-2-yl)-3,7-diazabicyclo[3.3.1]nonane-1-one, is known to have an S=1 electronic ground state and to be an extremely reactive oxidant for oxygen atom transfer (OAT) and hydrogen atom abstraction (HAA) processes. Here we show that, in spite of this ferryl oxidant having the “wrong” spin ground state, it is the most reactive nonheme iron model system known so far and of a similar order of reactivity as nonheme iron enzymes (C−H abstraction of cyclohexane, −90 °C (propionitrile), t1/2=3.5 sec). Discussed are spectroscopic and kinetic data, supported by a DFT-based theoretical analysis, which indicate that substrate oxidation is significantly faster than self-decay processes due to an intramolecular demethylation pathway and formation of an oxido-bridged diiron(III) intermediate. It is also shown that the iron(III)-chlorido-hydroxido/cyclohexyl radical intermediate, resulting from C−H abstraction, selectively produces chlorocyclohexane in a rebound process. However, the life-time of the intermediate is so long that other reaction channels (known as cage escape) become important, and much of the C−H abstraction therefore is unproductive. In bulk reactions at ambient temperature and at longer time scales, there is formation of significant amounts of oxidation product – selectively of chlorocyclohexane – and it is shown that this originates from oxidation of the oxido-bridged diiron(III) resting state. 相似文献