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71.
72.
The synthesis of diaryloxydiazirines, precursors to diaryloxycarbenes, is described. Thermolyses of the diazirines afford anticipated carbene products, but photolyses afford both carbenes and aryloxy radicals by alpha-scission. UV spectra of the carbenes and radicals are observed. [reaction: see text] 相似文献
73.
A novel Ru(II) complex possessing two sequentially linked viologen units, Ru-V(1)-V(2)(6+), was synthesized and characterized. Upon excitation of the Ru(II) unit (lambda(exc) = 532 nm, fwhm approximately 10 ns), a long-lived charge-separated (CS) state is observed (tau = 1.7 micros) by transient absorption spectroscopy. Unlike Ru(bpy)(3)(2+), which cleaves DNA upon photolysis through the formation of reactive oxygen species, such as (1)O(2) and O(2)(-), the photocleavage of plasmid DNA by Ru-V(1)-V(2)(6+) is observed both in air and under N(2) atmosphere (lambda(irr) > 395 nm). 相似文献
74.
Poon T Sivaguru J Franz R Jockusch S Martinez C Washington I Adam W Inoue Y Turro NJ 《Journal of the American Chemical Society》2004,126(34):10498-10499
Oxazolidinone-functionalized enecarbamates react stereoselectively with singlet oxygen to give methyldesoxybenzoin (MDB) in moderate to high enantiomeric excess. The stereochemical outcome depends on the E/Z substrate geometry, temperature, and solvent variables. The analysis of the differential activation parameters suggests a large contribution from the entropy term in determining the enantioselectivity. We demonstrate the utility of the temperature and solvent variables in determining the degree of the photochemical kinetic resolution of the enecarbamates; for example, in the photooxygenation at -70 degrees C in methanol, MDB may be obtained in methanol. 相似文献
75.
76.
Angela Mammana Dr. Gennaro Pescitelli Dr. Tomohiro Asakawa Dr. Steffen Jockusch Dr. Ana G. Petrovic Dr. Regina R. Monaco Dr. Roberto Purrello Prof. Nicholas J. Turro Prof. Koji Nakanishi Prof. George A. Ellestad Dr. Milan Balaz Prof. Nina Berova Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(44):11765-11765
77.
Wines TH Somasundaran P Turro NJ Jockusch S Ottaviani MF 《Journal of colloid and interface science》2005,285(1):318-325
Amphiphilic polymers can be used as tools to manipulate the behavior of reverse microemulsions. EPR spectroscopy employing the spin probe 5-doxyl stearic acid was used to study the adsorption of a comb type polymer (polymaleic anhydride octyl vinyl ether) and a diblock polymer (polybutadiene-ethylene oxide) onto reverse microemulsion droplets formed from Aerosol-OT/heptane/water. The findings indicate that the comb type polymer was adsorbed by the reverse microemulsion drops at low polymer concentrations causing a structural change of the micelle. 相似文献
78.
Sivaguru J Saito H Poon T Omonuwa T Franz R Jockusch S Hooper C Inoue Y Adam W Turro NJ 《Organic letters》2005,7(11):2089-2092
[reaction: see text]. Oxazolidinone-functionalized enecarbamates show contrasting behavior upon oxidation by singlet oxygen and by ozone. The observed stereoselectivity difference indicates that the oxidation with ozone is subject to classic steric effects, whereas the very high selectivity in the photooxidation with singlet oxygen is derived from vibrational deactivation. 相似文献
79.
80.
Nicholas J. Turro Yoshifumi Tanimoto Gavriella Gabor 《Photochemistry and photobiology》1980,31(6):527-532
Abstract— The absorption and fluorescence spectra of two functional ionic detergents containing an indole chromophore have been studied as micelle probes and have been compared to the corresponding spectra of 1-methylindole. The quenching of the fluorescence of the probes by NO- 2 and Co2+ has also been investigated. Based on the results obtained, it is concluded that 1-methylindole is associated with the surface of HDTBr micelles, whereas it is located in the interior of SDS micelles. The chromophore of the indole detergents is considered to be located in the interior of HDTBr and SDS micelles. 相似文献