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31.
R. Wallace 《Chemical physics letters》1976,37(1):115-118
The approximate eigenfunctions of the Morse oscillator, expressed in terms of Laguerre polynomials, are shown to form an approximately orthogonal basis. Analytic expressions for the matrix elements of common operators are obtained within this representation. With such matrix elements in closed form, the Morse oscillator becomes, as the harmonic oscillator has been, a practical building block in molecular theory. 相似文献
32.
Duane C. Wallace 《International journal of quantum chemistry》1994,52(2):425-435
The multiparticle correlation expansion for the entropy of a classical monatomic liquid is presented. This entropy expresses the physical picture in which there is no free particle motion, but, rather, each atom moves within a cage formed by its neighbors. The liquid expansion, including only pair correlations, gives an excellent account of the experimental entropy of most liquid metals, of liquid argon, and of the hard-sphere liquid. The pair correlation entropy is well approximated by a universal function of temperature. Higher-order correlation entropy, due to n-particle irreducible correlations for n ≥ 3, is significant in only a few liquid metals, and its occurrence suggests the presence of n-body forces. When the liquid theory is applied to the study of melting, we discover the important classification of normal and anomalous melting, according to whether there is not or is a significant change in the electronic structure upon melting, and we discover the universal disordering entropy for melting of a monatomic crystal. Interesting directions for future research are extension to include orientational correlations of molecules, theoretical calculation of the entropy of water, application to the entropy of the amorphous state, and correlational entropy of compressed argon. We clarify the relation among different entropy expansions in the recent literature. © 1994 John Wiley & Sons, Inc. 相似文献
33.
[reaction: see text] The palladium-catalyzed coupling of a range of enol triflates with amides, carbamates, and sulfonamides has been developed. This offers a simple and widely applicable synthesis of enamides, which may not be readily available by other means. 相似文献
34.
35.
Marcantonio KM Frey LF Liu Y Chen Y Strine J Phenix B Wallace DJ Chen CY 《Organic letters》2004,6(21):3723-3725
[reaction: see text] The palladium-catalyzed cyanation reaction is known to be sensitive to dissolved cyanide. Investigation into some causes of high levels of dissolved cyanide is presented here, along with a robust solution to this problem. 相似文献
36.
The metabolism of (+/-)fenfluramine, 1-(m-trifluoromethylphenyl)-2-N-ethylpropane, an anoretic agent, was investigated in humans. The analysis method was based on the use of ion-exchange resin extraction, solid-phase purification on the Bond Elut1M C8 cartridge, gradient elution high-performance liquid chromatography, enzymic hydrolysis of conjugates, further purification by Bond Elut C8 cartridge, derivatisation and capillary column gas chromatography-mass spectrometry (GC-MS). After administration of a 1 mg kg-1 oral dose, four metabolites plus unchanged fenfluramine were recovered in the 0-24 h urine from human volunteers and characterised by GC-MS. In the conjugated form, fenfluramine, norfenfluramine and m-trifluoromethylhippuric acid were detected by GC-MS. In the aglycone form, the major metabolite, 1-(m-trifluoromethylphenyl)-1,2-propane diol (fenfluramine diol), was monitored using GC-MS. The mass spectral characteristics of the m-trifluoromethylhippuric acid methyl ester, 1-(m-trifluoromethylphenyl)-1,2-propane ditrifluoracetate derivatives and the norfenfluramine and fenfluramine free base obtained under electron-impact ionization are presented. The metabolism of fenfluramine is discussed including a metabolic pathway in man accounting for the formation of its biotransformation products. 相似文献
37.
We report a novel source of tunable, coherent radiation in the vacuum ultraviolet, which use resonantly enhanced difference-frequency mixing in xenon gas Efficiencies are high (o.4%) at modest input laser intensities. With existing dye lasers the range of tunability will span the 152–200 nm region. 相似文献
38.
39.
Rajeev Rajasekharan‐Nair Dean Moore Dr. Kirsten Chalmers Dr. Dawn Wallace Louise M. Diamond Lisa Darby Dr. David R. Armstrong Dr. John Reglinski Dr. Mark D. Spicer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(7):2487-2495
The alkylation reactions of soft scorpionates are reported. The hydrotris(S‐alkyl‐methimazolyl)borate dications (alkyl=methyl, allyl, benzyl), which were prepared by the reaction of TmMe anion and primary alkyl halides, have been isolated and structurally characterised. The reaction is, however, not universally successful. DFT analysis of these alkylation reactions (C?S versus B? H alkylation) indicates that the observed outcome is driven by kinetic factors. Extending the study to incorporate alternative imine thiones (mercaptobenzothiazole, bz; thiazoline, tz) led to the structural characterisation of di[aquo‐μ‐aquohydrotris(mercaptobenzothiazolyl)boratosodium], which contains sodium atoms in the κ3‐S,S,S coordination mode. Alkylation of Na[Tbz] and Na[tzTtz] leads to decomposition resulting in the formation of the simple S‐alkylated heterocycles. The analysis of the species involved in these reactions shows an inherent weakness in the B? N bond in soft scorpionates, which has implications for their use in more advanced chemistry. 相似文献
40.
Warburton RE McCarthy A Wallace AM Hernandez-Marin S Hadfield RH Nam SW Buller GS 《Optics letters》2007,32(15):2266-2268
We demonstrate subcentimeter depth profiling at a stand off distance of 330 m using a time-of-flight approach based on time-correlated single-photon counting. For the first time to our knowledge, the photon-counting time-of-flight technique was demonstrated at a wavelength of 1550 nm using a superconducting nanowire single-photon detector. The performance achieved suggests that a system using superconducting detectors has the potential for low-light-level and eye-safe operation. The system's instrumental response was 70 ps full width at half-maximum, which meant that 1 cm surface-to-surface resolution could be achieved by locating the centroids of each return signal. A depth resolution of 4 mm was achieved by employing an optimized signal-processing algorithm based on a reversible jump Markov chain Monte Carlo method. 相似文献