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91.
Theoretical and Mathematical Physics - The problem of providing complete presentations of reduction algebras associated to a pair of Lie algebras $$( \mathfrak{G} , \mathfrak{g} )$$ has previously... 相似文献
92.
Richard T. Newcomb II Jianzhong Su II 《Proceedings of the American Mathematical Society》1996,124(5):1411-1415
We define a class of weakly coercive Hamiltonians and then demonstrate the single valuedness of the associated Hamilton-Jacobi operators (in the viscosity sense).
93.
E. Kuchta R. J. Alvarez II Y. H. Li D. A. Krueger C. Y. She 《Applied physics. B, Lasers and optics》1990,50(2):129-132
The Doppler-free line shape of the 6s
2
1
S
0 – 6s
16p
1
1
P
1 transition at 553.5 nm in natural Ba in the presence of an argon or helium buffer gas has been measured at 744 K for gas pressures from 0.2 to 100 Torr. Using the measured data for pressures above 5 Torr, the broadening rate coefficients for the half width at half maximum (HWHM) are determined to be (4.9±0.5)10–9 and (5.0±0.5)10–9 s–1 cm–3 for helium and argon respectively. 相似文献
94.
Daryle H. Busch Rebecca A. Roesner Thomas L. Allison II Elena V. Rybak-Akimova Liszu Chung 《Journal of inclusion phenomena and macrocyclic chemistry》1998,30(3):185-196
The compressibilities of seven liquidphase, macrocyclic host-guest systems were determinedat approximately 25 °C and 3.4 × 107 Pa.Each two-component system consisted of a cyclodextrin,a calixarene, or a crown ether as host and anappropriate solvent as guest. In each case studied,the host-guest system was found to be lesscompressible than the pure solvent, with thedifferences ranging from 2 to 18% of the magnitudesof the pure solvent compressibilities. These findingshave enabled us to better understand how strong,ambient pressure, intermolecular host–guestinteractions influence the compressibility ofsolutions. Both inclusion and solvationcontribute. 相似文献
95.
液相色谱-电喷雾离子阱质谱法测定贝类中软骨藻酸 总被引:1,自引:0,他引:1
记忆缺失性贝类毒素(amnesicshellfishtoxin,简称.ASP)主要成分软骨藻酸(domoicacid,简称DA)是一种氨基酸类的生理活性物质(图1),因最早从红藻属的树枝软骨藻(chondriaarmata)分离出来而被命名为软骨藻酸。自1987年加拿大首次发生集体贝类食品中毒事件后,人们从赤潮藻类中的硅藻属(diatom)的多列尖刺菱形藻(nitzschpungensf.multiseries)中检测到了DA,随后,美国、加拿大、北欧一些国家,澳大利亚、日本等国先后从紫贻贝(myltilusedulis)、扇贝(pectenmaximus)、文蛤(callistachione)等贝类体内以及鲭鱼和石蟹的内脏中检测到了DA。鱼、贝通过滤食毒藻,将DA富积在体内,人类因食用被DA污染的鱼、贝而中毒,中毒症状包括恶心、呕吐、腹痛、腹泻等,同时有晕眩、 相似文献
96.
K. Kuroda E. S. Wilkins Jr C. E. Willoughby E. O. Kraemer F. L. Smith II S. L. Tompsett R. F. Hanzal B. R. Burmester R. R. Roepke H. H. Green J. C. Morgan E. J. King G. E. Vladimirov J. A. Epstein L. D. Behr J. W. Palmer G. Blumenthal und H. T. Clarke 《Fresenius' Journal of Analytical Chemistry》1937,108(1-2):73-80
Ohne Zusammenfassung 相似文献
97.
Prof. Dr. Andreas Gansäuer Dr. Daniel von Laufenberg Dr. Christian Kube Tobias Dahmen Antonius Michelmann Dr. Maike Behlendorf Rebecca Sure Meriam Seddiqzai Prof. Dr. Stefan Grimme Dr. Dhandapani V. Sadasivam Godfred D. Fianu Prof. Dr. Robert A. Flowers II 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):280-289
An atom‐economical and catalytic arylation of epoxide‐derived radicals is described. The key step of the catalytic system is a sequential electron and proton transfer for the rearomatization of the radical σ‐complex and catalyst regeneration. Kinetic, computational, spectroscopic, and cyclovoltammetric investigations highlight the key issues of the reaction mechanism and catalyst stabilization by collidine hydrochloride. Studies employing radicophiles rule out the participation of cations as reactive intermediates. 相似文献
98.
The ν3 band of UF6 isolated in solid xenon is shown to consist of a single sharp spectral feature. 相似文献
99.
James J. Devery III James J. Douglas John D. Nguyen Kevin P. Cole Robert A. Flowers II Corey R. J. Stephenson 《Chemical science》2015,6(1):537-541
Knowledge of the kinetic behavior of catalysts under synthetically relevant conditions is vital for the efficient use of compounds that mediate important transformations regardless of their composition or driving force. In particular, these data are of great importance to add perspective to the growing number of applications of photoactive transition metal complexes. Here we present kinetic, synthetic, and spectroscopic evidence of the mechanistic behavior of fac-Ir(ppy)3 in a visible light-mediated radical addition to 3-methylindole, demonstrating the instability of fac-Ir(ppy)3 under these conditions. During the reaction, rapid in situ functionalization of the photocatalyst occurs, eventually leading to deactivation. These findings demonstrate a conceivable deactivation process for catalytic single electron reactions in the presence of radicophilic ligands. Attempts to inhibit photocatalyst deactivation through structural modification provide further insight into catalyst selection for a given system of interest. 相似文献
100.
An experimental investigation was conducted on the performance and boundary layer characteristics of the Wortmann FX 63-137 airfoil with and without trip wire roughness. Data were obtained through use of a three-component strain gage force balance and static pressure measurement equipment at a test Reynolds number of R c = 100,000. Emphasis was placed on determining the effect of trip wire placement and size on such performance parameters as (C l /C d )max and (C l 3/2 /C d )max. Prediction of transition location by the criterion due to Tani and Gibbings was found to have limited application. Most trip wire locations resulted in degraded performance, but for some locations, minimum drag was reduced, maximum lift to drag ratio increased, and hysteresis averted. 相似文献