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21.
22.
The primary amino group of 3-(2-aminoethyl)-3-(4-chlorophenyl)-2,3-dihydro-1H-isoindol-1-one ( 1 ) was acylated with acetyl chloride, benzoyl chloride and phenyl acetyl chloride to form the amides 2a -c, respectively. These were cyclized in phosphorus oxychloride to give the 1-substituted-4a-(4-chlorophenyl)-4,4a-dihydropyrimido [6,1-a]isoindol-9(3H)-ones 3a-c . Heating of 1 in formic acid lead to the formation of 4a-(4-chlorophenyl)-4,4a-dihydropyrimido[6,1-a]isoindol-9(3H) -one (3d) . Heating of 1 in the presence of phosgene lead to the formation of 4a-(4-chlorophenyl)-2,3,4,4a-tetrahydropyrimido[6,1-a]isoindole-1, 9-dione (4). 相似文献
23.
The correlation between the intensities of the M+˙ and [M ? H]+ ions of 47 cyclic acetals and thioacetals of alkyl formylphenoxyacetates and propionates as well as the fragmentation patterns in the vicinity of the molecular ion are discussed. The characteristic differences between the spectra of 1,3-dioxolanes, 1,3-oxathiolanes, 1,3-dithiolanes and 1,3-dioxanes are presented. 相似文献
24.
Izabela Michalak Agnieszka Saeid Katarzyna Chojnacka 《Central European Journal of Chemistry》2013,11(2):313-319
In this study, the effect of the increase in the initial concentration of Na(I) ions in the solution during biosorption of Cr(III) ions by two edible algae: marine macroalga — Enteromorpha prolifera and microalga — Spirulina sp. was investigated. During biosorption, essential elements are exchanged with alkali and alkaline earth metal ions (e.g. Na(I) ions), which are naturally bound with the biomass. The goal of this study was to investigate the effect of the increase in concentration of Na(I) ions on biosorption performance. The equilibrium of the process is described by Langmuir equation. It was found that with the increase in the initial concentration of NaCl (from 132 to 7331 mg L?1), there was a lower biosorption capacity of Enteromorpha prolifera (from 85.8 to 51.0 mg g?1) and Spirulina sp. (74.2 to 20.7 mg g?1) towards Cr(III) ions. It was also possible to determine the number of times the solution used in the biosorption process can be recycled and yet mantain high biosorption capacity. The determined numbers were: 16 for Enteromorpha prolifera and 19 for Spirulina sp. 相似文献
25.
26.
The mass spectra of some tertiary aliphatic nitroaldehydes, nitroketones, nitroesters, nitronitriles and related nitrocarbonyl compounds are discussed and compared with those of some analogous nitro compounds lacking the carbonyl function. The M+˙ ? NO2˙ and in several cases M+˙ ? HNO2 fragmentation seem to be the most characteristic features of all tertiary aliphatic nitro compounds. In the presence of the primary nitro group, the loss of NHO2 is always observed. 相似文献
27.
Summary. Several compounds may exist in LnCl3–MCl mixtures. Those corresponding to the M
2
LnCl5 and MLn
2Cl7 stoichiometries are formed in a few systems only, with diverse stability strongly dependent on both the corresponding lanthanide
and alkali metal. On the other hand, M
3
LnCl6 that occur in most systems have a far larger stability range and melt congruently. These latter compounds were investigated
in the present work by differential scanning calorimetry and electrical conductivity measurements. The thermodynamic and transport
properties were correlated to structural features and related to the mechanism of compound formation.
Corresponding author. E-mail: Marcelle.Gaune-Escard@polytech.univ-mrs.fr
Received October 2, 2002; accepted November 6, 2002
Published online April 24, 2003
RID="a"
ID="a" This paper is dedicated to Professor H. Gamsj?ger on the occasion of his birthday 相似文献
28.
Iwona E. Malka Tomasz Czujko Jerzy Bystrzycki Leszek R. Jaroszewicz 《Central European Journal of Chemistry》2011,9(4):701-705
The hydrogenation properties of magnesium hydride mechanically milled with iron fluorides (FeF2 and FeF3), were investigated by Temperature Programmed Desorption (TPD) and volumetric methods using a Sieverts-type apparatus, as
prepared upon dehydrogenation and finally upon subsequent hydrogenation. The activation energy of hydrogen desorption (Ea), calculated from the Kissinger formula using TPD measurements obtained with different heating rates, showed significant
decreases of Ea in comparison to that of milled MgH2 without any dopants. Moreover, the influence of these metal fluorides on the thermodynamics of the decomposition process
was also examined. In the case of the FeF2 dopant, rehydrogenation following desorption caused the complete decomposition of the iron fluoride to BCC iron and the formation
of a predominant MgH2 phase. In contrast to FeF2, the addition of FeF3 led to the formation of β-MgH2 as a major phase coexisting with Mg2FeH6 and MgF2 compounds. The presence of pure Fe in the MgH2+FeF2 composite, as opposed to MgH2+FeF3 containing Mg2FeH6 and MgF2, did not cause any significant influence on the sorption properties of MgH2. Moreover, the original material doped with FeF3 predominantly showed iron in the Mg2FeH6 compound, while the FeF2 dopant iron mostly showed the nearly pure BCC metallic phase
相似文献
29.
On the basis of conventional scaling theory, the two-point scaling theory was modified in order to describe the influence
of composition on the partial molar heat capacity and volume during the micellization process. To verify the theory, isobaric
heat capacities and densities of aqueous sodium octanoate solutions were measured over wide composition and temperature ranges
and the modified approach was used to analyze the calculated partial molar heat capacities and volumes of the surfactant in
water. The results obtained indicate that the micellization process is subject to the scaling laws. The results were compared
with those for other systems. Peculiar behavior of the critical indices was observed and correlated with the structure of
the micelles. 相似文献
30.