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11.
Determination of molybdenum in plasma using graphite furnace atomic absorption spectrometry 总被引:1,自引:0,他引:1
A sensitive method is described for the determination of Mo in plasma or serum by graphite furnace atomic absorption spectrometry. The method involves extraction of the metal as the 8-hydroxyquinoline complex and is free of the interference effects that prevent the direct analysis of plasma for Mo. Recoveries of internal standards were excellent and results from the analysis of a National Institute of Standards and Technology Standard Reference Material were in good agreement with certified values. The sensitivity of the method, based on the analysis of 1 ml of plasma, is ca. 3 ng ml-1. 相似文献
12.
Rhodium(II) catalysts and PhIO in benzene convert homoallylic carbamates into the corresponding aziridines at room temperature. 相似文献
13.
Filby MH Humphries TD Turner DR Kataky R Kruusma J Steed JW 《Chemical communications (Cambridge, England)》2006,(2):156-158
Two types of calix[4]arene derived hosts for anions with, respectively, 1,3-alternate and cone conformations have been prepared; the 1,3-alternate system binds dicarboxylate anions in a ditopic manner while the cone compounds are deprotonated by carboxylates. 相似文献
14.
A weak Cayley table isomorphism is a bijection φ: G → H of groups such that φ(xy) ~ φ(x)φ(y) for all x, y ∈ G. Here ~denotes conjugacy. When G = H the set of all weak Cayley table isomorphisms φ: G → G forms a group 𝒲(G) that contains the automorphism group Aut(G) and the inverse map I: G → G, x → x ?1. Let 𝒲0(G) = ?Aut(G), I? ≤ 𝒲(G) and say that G has trivial weak Cayley table group if 𝒲(G) = 𝒲0(G). We show that all finite irreducible Coxeter groups (except possibly E 8) have trivial weak Cayley table group, as well as most alternating groups. We also consider some sporadic simple groups. 相似文献
15.
Stephen P. Humphries 《代数通讯》2013,41(4):1233-1242
In this paper we show that the braid groups B n and the symmetric automorphism groups H(n) of the free group F n,n = 3,4 act in a non-linear way on an algebra with straightening law (ordinal Hodge algebra). We indicate various properties of these rings. 相似文献
16.
Filby MH Dickson SJ Zaccheroni N Prodi L Bonacchi S Montalti M Paterson MJ Humphries TD Chiorboli C Steed JW 《Journal of the American Chemical Society》2008,130(12):4105-4113
The synthesis, photophysical, and anion-binding properties of a series of di-, tri-, and tetrapodal anion-binding hosts based on aminopyridinium units with pyrenyl reporter groups are described. The ditopic mesitylene-derived calix[4]arene-based host 4 binds strongly to dicarboxylates, particularly malonate, in a 2:1 anion:host ratio but is essentially nonemissive in the presence of all anions except chloride because of intramolecular quenching by the pyridinium units. Addition of chloride results in a conformational change, giving an initial increase in emission assigned to intramolecular excimer formation. Further chloride addition also results in an increase in the intensity of the pyrenyl monomer emission as chloride binding reduces the acceptor ability of the pyridinium groups. This behavior is not exhibited by control compounds 5 and 6, which lack the ditopic geometry and calixarene spacer unit; however, tripodal 6 forms 1:2 anion:host complexes with a range of anions. 相似文献
17.
18.
The purpose of this paper is to investigate the problem of finding the common element of the set of common fixed points of a countable family of nonexpansive mappings, the set of an equilibrium problem and the set of solutions of the variational inequality prob- lem for a relaxed cocoercive and Lipschitz continuous mapping in Hilbert spaces. Then, we show that the sequence converges strongly to a common element of the above three sets under some parameter controlling conditions, which are connected with Yao, Liou, Yao[17], Takahashi[12] and many others. 相似文献
19.
Rutkowski H.L. Hewett D.W. Humphries S. Jr. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1991,19(5):782-789
An overview of the development of arc ion sources for heavy ion fusion is presented. Two approaches to heavy ion fusion (HIF)-the RF linac-storage ring approach and the induction linac approach-are described. RF linac schemes require low emittance and moderate current levels, because the beam is accumulated in storage rings before being focused on target. The induction linac approach requires low emittance and high current, because this is a single-pass approach to HIF and one wishes to limit the number of beams in the machine. The RF scheme generally uses long pulse sources together with a buncher of RFQ. The induction linac approach requires sources in the microsecond pulse length range, with good optics being maintained during the pulse. Emphasis is on the induction linac approach pursued at the Lawrence Berkeley Laboratory 相似文献
20.