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391.
The excess volumes of mixing of cyclohexylamine with n-hexane, n-heptene, n-octane, n-nonane, benzene, toluene, nitrobenzene, chlorobenzene and bromobenzene have been measured at 30°C. For all systems except for n-hexane, V
E
is positive over the entire mole fraction range. For the n-hexane mixtures, a sigmoid curve is obtained with negative V
E
at high mole fraction of amine. 相似文献
392.
I. García de la Fuente J. A. González J. C. Cobos C. Casanova 《Journal of solution chemistry》1995,24(8):827-835
The excess molar volumes V
m
E
at atmospheric pressure and at 25°C for binary mixtures of diethyl carbonate with n-heptane, n-decane, n-tetradecane, 2,2,4-trimethylpentane, cyclohexane, benzene, toluene, or tetrachloromethane have been obtained over the whole mole-fraction range from densities measured with a vibrating-tube densimeter. The V
m
E
are positive for all the systems investigated, except for the mixture with toluene which is negative. The results for V
m
E
together with data previously published on excess molar enthalpies H
m
E
and excess molar Gibbs energies G
m
E
, suggest interactions between carbonate and hydrocarbons which are stronger with aromatic than with aliphatic hydrocarbons.Thermodynamics of binary mixtures containing organic carbonates, Part 10. 相似文献
393.
394.
合成了一系列硅铝比为31—176的ZSM-11沸石,以甲苯-甲醇烷基化、间二甲苯异构化和甲苯歧化三个反应作为探针反应,研究了它们的催化性能。将其与酸性质和晶胞参数相关联发现,低硅铝比适于甲苯歧化,中硅铝比适于间二甲苯异构化,高硅铝比适于甲苯-甲醇烷基化反应。各反应所需的酸强度为甲苯歧化>间二甲苯歧化>间二甲苯异构化>甲苯-甲醇烷基化。Na~+的存在以及用4-甲基喹啉或(CH_3)_3SiCl中毒,可抑制强酸位,明显提高甲苯-甲醇烷基化反应生成对二甲苯的选择性,尤以(CH_3)_3SiCl中毒的低Al/u.c.的NaHZSM-11最佳。 相似文献
395.
Gas phase selective catalytic oxidation of toluene to benzaldehyde was studied on V2O5-Ag2O/η-Al2O3 catalyst prepared by impregnation. The catalyst was characterized by XRD, XPS, TEM,and FT-IR. The catalytic results showed that toluene conversion and selectivity for benzaldehyde on catalyst sample No.4 (V/(V Ag)=0.68) was higher than other catalysts with different V/Ag ratios. This was attributed to the higher surface area, larger pore volume and pore diameter of the catalyst sample No.4 than the other catalysts. The XRD patterns recorded from the catalyst before and after the oxidation reaction revealed that the new phases were developed, and this suggested that silver had entered the vanadium lattice. XPS results showed that the vanadium on the surface of No.4 and No.5 sample was more than that in the bulk, thus forming a vanadium rich layer on the surface. It was noted that when the catalyst was doped by potassium promoter, the toluene conversion and selectivity for benzaldehyde were higher than those on the undoped catalyst. This was attributed to the disordered structure of V2O5 lattice of the K-doped catalyst and a better interfacial contact between the particles. 相似文献
396.
Atri Deo Tripathi 《Journal of solution chemistry》1994,23(7):769-776
Relative permittivities are reported for binary liquid mixtures of acetylene tetrachloride (ATC) with toluene and acetone at 35°C. Measurements of refractive indices have also been made for the mixtures. The values of the quantity , the deviations of the relative permittivities of these mixtures from ideality, have been calculated. The negative values of obtained for ATC+ toluene mixtures may be explained as being due to a decrease in the degree of alignment of the molecular dipoles with changing composition of the mixture, whereas the positive values of obtained for ATC+acetone mixtures are attributed to the formation of molecular complex between acetone and CHCl2CHCl2. The values of the Kirkwood correlation parameter g for both sets of mixtures have been calculated using the relative permittivity data. 相似文献
397.
M. A. Ryashentseva 《Chemistry of Heterocyclic Compounds》2006,42(8):1018-1020
In the presence of Pd-and Cr-containing catalysts applied to γ-Al2O3 or sibunite 4,5,6,7-tetrahydroindole is converted into indole. Indole was obtained in quantitative yield on sulfided 0.15–0.5%
Pd/γ-Al2O3 catalyst at 360°C and on catalysts containing 5% Cr2O3, 5% La2O3 (or 5% polirit), 1% K2O/89% γ-Al2O3 at 475–480°C.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1176–1178, August, 2006. 相似文献
398.
Emmerich Wilhelm E. Jimenez G. Roux-Desgranges J. -P. E. Grolier 《Journal of solution chemistry》1991,20(1):17-28
Excess molar volumes V
E
and excess molar heat capacities C
P
E
at constant pressure have been measured, at 25°C, as a function of composition for the four binary liquid mixtures propylene carbonate (4-methyl-1,3-dioxolan-2-one, C4H6O3; PC) + benzene (C6H6;B), + toluene (C6H5CH3;T), + ethylbenzene (C6H5C2H5;EB), and + p-xylene (p-C6H4(CH3)2;p-X) using a vibrating-tube densimeter and a Picker flow microcalorimeter, respectively. All the excess volumes are negative and noticeably skewed towards the hydrocarbon side: V
E
(cm3-mol–1) at the minimum ranges from about –0.31 at x1=0.43 for {x1C4H6O3+x2p-C6H4(CH3)2}, to –0.45 at x1=0.40 for {x1C4H6O3+x2C6H5CH3}. For the systems (PC+T), (PC+EB) and (PC+p-X) the C
P
E
s are all positive and even more skewed. For instance, for (PC+T) the maximum is at x
1,max
=0.31 with C
P,max
E
=1.91 J-K–1-mol–1. Most interestingly, C
P
E
of {x1C4H6O3+x2C6H6} exhibits two maxima near the ends of the composition range and a minimum at x
1,min
=0.71 with C
P,min
E
=–0.23 J-K–1-mol–1. For this type of mixture, it is the first reported case of an M-shaped composition dependence of the excess molar heat capacity at constant pressure.Communicated at the Festsymposium celebrating Dr. Henry V. Kehiaian's 60th birthday, Clermont-Ferrand, France, 17–18 May 1990. 相似文献
399.
Infrared spectra of M(1,8-diaminooctane)Ni(CN)4G (M= Co, Ni or Cd; G=benzene, chlorobenzene, toluene, p-xylene, naphthalene or biphenyl) compounds are reported. The 1,8-diaminooctane molecules in the host permit the inclusion of bulky guest molecules. The spectral features suggest that the compounds are similar in structure to the Hofmann-type clathrates. 相似文献
400.