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91.
Xiaoxiao Dong Hong Zhao Zhihang Wang Miray Ouzounian Travis Shihao Hu Yongjian Guo Lipeng Zhang Quan Xu 《中国化学快报》1990,30(12):2333-2337
Enhanced dry self surfaces were fabricated which could dislodge up to 24.6% of contaminated particles with as few as 4 steps. 相似文献
92.
Taylor S. Alexander Travis J. Clay Bryan Maldonado Johny M. Nguyen David B.C. Martin 《Tetrahedron》2019,75(14):2229-2238
The γ-arylation of substituted silyl-activated butenolides has been studied using a broad scope of unsymmetrical hypervalent diaryliodonium salts via a palladium- or copper-catalysed coupling reaction, yielding interesting reactivity trends. The mild catalytic conditions and coupling partner variability provide access to synthetically useful building blocks toward the pursuit of aryl-lactone containing natural products and allows for facile diversification. 相似文献
93.
The application of cyclopropenium ion as a phase transfer catalyst for benzylic fluorination in high yields is reported. Integral to the mechanisms of these fluorination reactions was the role of in situ derived cyclopropenium fluoride complexes, the existence of which was supported by 1H, 19F NMR and UV–Vis spectroscopy. Density functional theory calculations were applied to gain insight into the mechanism of these reactions. 相似文献
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97.
Sally M. McIntyre Jill Wisnewski Ferguson Travis M. Witte R.S. Houk 《Spectrochimica Acta Part B: Atomic Spectroscopy》2011,66(3-4):248-254
The general method of comparing measured ion ratios to calculated ion ratios to determine a gas kinetic temperature (Tgas) is reviewed. Various mathematical refinements to the calculated partition functions are examined for their effect on the determined Tgas. It is found that (a) excited electronic states should be included for ArO+, neutral NO, and O2; (b) a 10% error in solvent load, sample gas flow rate, vibrational constant (ω), rotational constant (B) or measured ion ratio produces only a 1 to 3% error in Tgas; (c) a 10% error in dissociation energy (D0) creates nearly a 10% error in Tgas; and (d) high temperature corrections to the partition functions produce minimal change and can generally be neglected. 相似文献
98.
We give a new Jacobi–Trudi-type formula for characters of finite-dimensional irreducible representations in type using characters of the fundamental representations and non-intersecting lattice paths. We give equivalent determinant formulas for the decomposition multiplicities for tensor powers of the spin representation in type and the exterior representation in type . This gives a combinatorial proof of an identity of Katz and equates such a multiplicity with the dimension of an irreducible representation in type . By taking certain specializations, we obtain identities for -Catalan triangle numbers, a slight modification of the -Catalan number of Stump, -triangle versions of Motzkin and Riordan numbers, and generalizations of Touchard’s identity. We use (spin) rigid tableaux and crystal base theory to show some formulas relating Catalan, Motzkin, and Riordan triangle numbers. 相似文献
99.
Diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid (DTPA) is an octadentate aminopolycarboxylate complexing agent whose f-element complexes find important practical applications in nuclear medicine and in advanced nuclear fuel reprocessing. This investigation focuses primarily on the latter application, specifically on characterization of lanthanide–DTPA complexes of relevance to the Trivalent Actinide–Lanthanide Separations by Phosphorus reagent Extraction and Aqueous Komplexants (TALSPEAK) process. To function acceptably, the TALSPEAK process requires the presence of moderate concentrations (0.5–2.0 mol·L?1) of a (Na+/H+) lactate (or citrate) buffer. Competition between DTPA, lactate, and the extractant bis(2-ethylhexyl)phosphoric acid (HDEHP) for the lanthanides and trivalent actinides governs the course of the extraction process. To facilitate modeling and to support process improvements, the acid dissociation constants and stability constants for rare earth complexes with DTPA have been determined in 2.0 mol·L?1 ionic strength (NaClO4) media. The acid dissociation constants for DTPA and the stability constant for [Eu(DTPA)]2? also were determined in sodium trifluoromethanesulfonate at 2.0 mol·L?1 ionic strength to evaluate the potential impact of changing the nature of the electrolyte. The thermodynamic data are compared with earlier reports of similar data at lower ionic strength and used to complete calculations exploring the relative stability of lanthanide–DTPA and lactate complexes under TALSPEAK extraction conditions. Lanthanide–DTPA stability trends are discussed in comparison with literature data on a variety of other metal ions. 相似文献
100.
Much of modern chemistry is concerned with the properties and dynamics of chemical bonds. Although they have been described variously, the most familiar representation is that of a link connecting two atoms. However, no one has yet developed a scheme by which to partition a molecule into bond volumes with well‐defined properties. As a consequence, the chemical bond is left as nothing more than a heuristic devise. Here, we show molecules can be partitioned into bond‐bundles–volumes that share many of the properties associated with the conceptual bond. This partitioning follows naturally through an extension of Baders topological theory of molecular structure. Surprisingly, it also bounds regions of space containing nonbonding or lone‐pair electrons and leads to bond orders consistent with those expected from theories of directed valance. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献