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111.
H. J. M. Bowen E. Page I. Valente R. J. Wade 《Journal of Radioanalytical and Nuclear Chemistry》1979,48(1-2):9-16
Radio-tracer experiments have shown that antimony, mercury and zinc interact to form complexes with humic and/or fulvic acids,
whose molar masses can be estimated by gel chromatography. Sb(III) and (V) humates are stable in the pH range 7–11, but are
largely dissociated below pH 4; humic acid does not reduce Sb(V) to Sb(III) in solution. Mercury forms a strong complex with
humic+fulvic acids. Zinc forms complexes with both humic acids and glycine, and the humic acid complex has similar elution
behaviour on dextran gel to a fraction from river water equilibrated with65Zn. At least one other form of zinc, in addition to Zn2+, occurs in this river. 相似文献
112.
An analysis of the contact mechanics and the forces of interaction in lateral force microscopy measurements is presented. This analysis allows for a new method of interpretation of the frictional forces, the lateral contact stiffness, and the contact shear strength. The technique was developed for the interpretation of frictional data obtained with colloidal probes, although results are presented which illustrate its ability to interpret measurements recorded with both colloidal probes and standard atomic force microscopy tips. The technique is found to compensate for the variations in the contact geometry, giving repeatable results for probes of different sizes. A critical review of other techniques which have been employed to interpret the frictional force in lateral force microscopy is also presented. Copyright 2000 Academic Press. 相似文献
113.
A procedure for the direct polarographic determination of aluminium is described, with particular reference to zinc-base die-casting alloys. Interfering elements are removed by electrolysis of a solution of the alloy in a mercury-cathode cell. The solution is polarographed at a carefully controlled pH in a supporting electrolyte of magnesium chloride and sodium sulfate of appropriate concentration. The precision and accuracy of the method are shown to be satisfactory by the analysis of standard samples from three different laboratories. 相似文献
114.
Equilibrium configurations of self-gravitating massless thermal radiation inside spherical boxes of radiusR in asymptotically anti-de Sitter space (A = -3/b
2) are constructed numerically for a range of central densities. For each box radius considered (R/b = 0, 1/2, 1, 2, 4, ), there is a unique configuration with maximal total mass and entropy, and another (at a lower central density) with maximum asymptotic red-shifted temperature. With the box removed toR=, the maximum total mass and entropy of self-gravitating thermal radiation areM
max 0.4598b0.7964(–A)–1/2 andS
max1.3560a
1/4
b
3/2 3.0910a
1/4(–A)–3/4, and the maximum red-shifted temperature is 相似文献
115.
116.
117.
Ryuto Kimura Yuh Hijikata Clothilde A. Eveleens Alister J. Page Stephan Irle 《Journal of computational chemistry》2019,40(2):375-380
Chemical vapor deposition (CVD) utilizing metal cluster nanoparticle catalysts is commonly used to synthesize carbon nanotubes (CNT), with oxygen-containing species such as water or alcohol included in the feedstock for enhanced yield. However, the etching effect of these additives on the growth mechanism has rarely been investigated, despite evidence suggesting that etching potentially affects the chirality distribution of product CNTs. We used quantum chemical methods to study how water-based etchant radicals (OH and H) may enhance the chiral selectivity during CVD growth using CNT cap models. Chemical reactivities of the caps with the etchant radicals were evaluated using density functional theory (DFT). It was found that the reactivities on the cap edges correlate with the chirality of the caps. These results suggest that proper selection of etchant species can provide opportunities for selective chirality control of the product CNTs. © 2018 Wiley Periodicals, Inc. 相似文献
118.
Electron paramagnetic resonance (EPR) investigations of Li2C2O4, Na2C2O4 mixed in proportion 1:0, 0:1, 1:1, 2:1 and 3:1 were carried out to measure the absorbed dose from photons and thermal neutrons in a mixed radiation field. A single line spectrum of CO2? radical anion centered around g=2.0045±0.0005 was obtained in the respective cases on gamma and neutron irradiation. Except Na2C2O4, other mixtures had shown increase in line width on neutron irradiation possibly due to relaxation effects. Of all combinations, the 2:1 mixture is the more sensitive material for gamma and thermal neutrons. Intensity of CO2? radical signal in 2:1 Li2C2O4:Na2C2O4 mixture was found to be linear from 0.006 to 11 kGy for gamma and 40–1530 kGy for thermal neutron doses. Radical signal was found to be stable over a period of 300 days with marginal fading of less than 1 percent. Experimental results thus obtained suggest 2:1 Li2C2O4:Na2C2O4 mixture as the potential neutron dosimeter for medium and high dose range. 相似文献
119.
D. N. Page 《Foundations of Physics》2009,39(10):1097-1108
A minor modification of the arguments of Press and Lightman leads to an estimate of the height of the tallest running, breathing
organism on a habitable planet as the Bohr radius multiplied by the three-tenths power of the ratio of the electrical to gravitational
forces between two protons (rather than the one-quarter power that Press got for the largest animal that would not break in
falling over, after making an assumption of unreasonable brittleness). My new estimate gives a height of about 3.6 meters
rather than Press’s original estimate of about 2.6 cm. It also implies that the number of atoms in the tallest runner is very
roughly of the order of the nine-tenths power of the ratio of the electrical to gravitational forces between two protons,
which is about 3×1032. 相似文献
120.
T. H. Page 《Analytical and bioanalytical chemistry》1904,43(6-7):414-414