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41.
High-resolution IR-UV multiple resonance methods are employed to elucidate the photodissociation dynamics of quantum state-selected Ar-HOD and Ar-H(2)O van der Waals clusters. A single mode pulsed OPO operating in the region of the OH second overtone is used to prepare individual rovibrational states that are selectively photodissociated at specific excimer wavelengths. Subsequent fluorescence excitation of the resulting OH (OD) fragments yields dynamical information on the photofragmentation event and any resulting intracluster collisions. This technique is used to characterize spectroscopically the Pi(1(01)), nu(OH)=3<--Sigma(0(00)), v(OH)=0 overtone band of the Ar-HOD complex with an origin at 10648.27 cm(-1). The effects of Ar complexation on the dissociation dynamics are inferred by comparison of the OD photofragment quantum state distributions resulting from dissociation of single rovibrational states of the complex with those from isolated HOD photodissociation. The important role played by the initial internal state of the complex is demonstrated by comparison of the current Ar-HOD data with previously published results for the Ar-H(2)O Sigma(0(00))[03(-)> state. We interpret the dramatic differences in the dynamics of the two systems as manifestations of the nodal structure of the vibrational state in the parent complex and the way in which it governs the collision probability between the Ar atom and the escaping photofragments. 相似文献
42.
A Monte Carlo correction program for quantitative microanalysis on PC computer is introduced in this paper. The elastic scattering is described by the screened Rutherford cross section. Instead of computing the energy loss according to the actual path between two scatterings we have defined the Bethe inelastic cross section determined by the Bethe-slowing-down approximation. It is assumed that it causes no angular departure of the scattered electron. In the second model we took into account the angular dependence of inelastic scattering assuming that the primary electron interacts with quasi-free atom electrons. On the basis of these two models analytical Monte Carlo programmes were developed and experimentally tested on some oxide glass. Our results are fully comparable to those obtained by ten world microprobe laboratories using classical ZAF correction or Bence-Albee methods. We have found that introducing angular part of the inelastic cross section analytical results did not significantly change. All of our results were carried out for bulk specimens but extending it to layers is under the development. 相似文献
43.
Ondrej imo Alfonz Rybr Juraj Alfldi Vladimír Ptoprstý 《Journal of heterocyclic chemistry》1999,36(2):453-456
The 6-(3-hydroxypropylamino)-3-methylpyrimidine-2,4-dione (1) did not afford the expected 6-(3-chloro-propylamino)- derivative on reaction with thionyl chloride, but, instead, the pyrimidine rings were joined via a sulfur bridge to give 9,9′-thiobis(1,2,3,4,7,8-hexahydro-7-melnyl-6H-pyrimido[1,6-a]pyrirnidine-6,8-dione) ( 3 ). An identical 9,9′-thiobis- derivative 3 was obtained when reacting thionyl chloride with 1,2,3,4,7,8-hexahydro-7-methyl-6H-pyrimido[1,6-a]pyrimidine-6,8-dione ( 4 ). We suppose the sulfoxide- derivative 2 to be the intermediate of both routes: it underwent reduction to the final sulfide 3 in excess thionyl chloride. 相似文献
44.
45.
Farhad Shahrokhi Ondrej Sýkora László A. Székely Imrich Vrt’o 《Discrete Applied Mathematics》2007,155(9):1106-1115
The k-planar crossing number of a graph is the minimum number of crossings of its edges over all possible drawings of the graph in k planes. We propose algorithms and methods for k-planar drawings of general graphs together with lower bound techniques. We give exact results for the k-planar crossing number of K2k+1,q, for k?2. We prove tight bounds for complete graphs. We also study the rectilinear k-planar crossing number. 相似文献
46.
Mariá n Fabian Ondrej F. K. Kalenda Jan Kolá r 《Proceedings of the American Mathematical Society》2005,133(1):295-303
If is an infinite-dimensional Banach space, with separable dual, and is an analytic set such that any point can be reached from by a continuous path contained (except for the point ) in the interior of , then is the range of the derivative of a -smooth function on with bounded nonempty support.
47.
Dr. Ondrej Kyseĺ 《International journal of quantum chemistry》1990,38(2):119-120
48.
W. Kundrat 《Fresenius' Journal of Analytical Chemistry》1968,243(1):624-630
Zusammenfassung Ein qualitativer Schnelltest für die Erfassung von Antibiotica, Sulfaniliden und anderen Chemotherapeutica wird beschrieben. Als Testkeim dient eine Reinkultur von Bac. stearothermophilus; die Testdauer beträgt bei einer Temperatur von 65° C nur 50 min. Die Methode ist für die Bestimmung von Reinigungs- und/oder Desinfektionsmitteln sowie für Konservierungsmittel ungeeignet.
Methods for the determination of residues of antibiotics in animal products
A rapid qualitative diffusiontest using Bac. stearothermophilus as test organism for the detection of antibiotics, sulphanilamides and other chemotherapeutic agents is described. The test requires 50 min at a temperature of 65° C. The method is not applicable to the evaluation of detergents, disinfectants and preservatives as used in food industry.相似文献
49.
This paper presents the synthesis of a series of 5,6‐dihydro‐4H,8H‐pyrimido[1,2,3‐cd]purine‐8,10(9H)‐dione ring system derivatives with a [1,2,3]triazole ring bonded in position 2. The procedure is based on cycloaddition of substituted alkyl azides to the terminal triple bond of 5,6‐dihydro‐2‐ethynyl‐9‐methyl‐4H,8H‐pyrimido[1,2,3‐cd]purine‐8,10(9H)‐dione ( 4 ). This cycloaddition produced two regioisomers ?5,6‐dihydro‐9‐methyl‐2‐(1‐substituted‐1H‐[1,2,3]triazol‐5‐yl)‐4H,8H‐pyrimido[1,2,3‐cd]purine‐8,10(9H)‐dione ( 7 ) and 2‐(1‐substituted‐1H‐[1,2,3]triazol‐4‐yl) derivative 8 . The required 2‐ethynyl deriva tive 4 was obtained from the starting 2‐unsubstituted compound 1 by bromination to yield the 2‐bromo derivative 2 , which was converted by Sonogashira reaction to trimethylsilylethyne 3 and finally, the protective trimethylsilyl group was removed by hydrolysis. 相似文献
50.