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101.
Bauer DA Belcinski R Berg RC Bingham HH Bloom ED Buchanan CD Caldwell DO Chun SB Clark AR Dahl OI Eastman JJ Eberhard PH Eisner AM Fairfield KH Godfrey G Greenbaum GS Hauptman JM Hofmann W Holtzapple RL Khacheryan S Knöpfle KT Kofler RR Lambert DJ Loken SC Lu A Lynch GR Lys JE Madaras RJ Marsiske H Masek GE Miller ES Nicol NA Nygren DR Oyang YT Paar HP Palounek AP Pellett DE Ronan MT Ross RR Shapiro G Stephens RW Stevenson ML Strauss MG Sullivan MK Vernon W Wang EM Wang YX Wenzel WA Yamamoto H 《Physical review D: Particles and fields》1994,50(1):R13-R17
102.
Christopher D. Chouinard Christopher R. Beekman Robin H. J. Kemperman Harrison M. King Richard A. Yost 《International Journal for Ion Mobility Spectrometry》2017,20(1-2):31-39
Drift tube ion mobility spectrometry (DTIMS) coupled with mass spectrometry was evaluated for its capabilities in rapid separation of endogenous isomeric steroids. These compounds, which included eight isomer groups, were investigated as protonated and sodiated species and collision cross sections were measured for all ionization species of each steroid. Pregnenolone (CCSN2 176.7 Å2) and 5α-dihydroprogesterone (CCSN2 191.4 Å2) could be separated as protonated species, and aldosterone (CCSN2 197.7 Å2) and cortisone (CCSN2 211.7 Å2) could be separated as sodiated monomers. However, the sodiated dimers of the remaining isomers yielded increased separation, resulting in baseline resolution. Specific structural differences including ring conformation and the chirality of hydroxyl groups were compared to evaluate their relative effects on collision cross section in isomers. These results indicated that C5 ring conformation isomers androsterone and etiocholanolone, which both contain a C3 α-hydroxyl group, yielded similar dimer CCS. Yet these compounds were well resolved from their respective β-hydroxyl epimers, trans-androsterone and epietiocholanolone. Alternative drift gases were evaluated, and carbon dioxide drift gas offered slight improvement in isomer resolution well, including allowing separation of testosterone (CCSCO2 330.0 Å2), dehydroepiandrosterone (CCSCO2 312.6 Å2), and epitestosterone (CCSCO2 305.6 Å2). Finally, different metal cation adducts, including alkali, alkaline earth, and first row transition metal adducts were analyzed, and several of these species provided improved resolution between steroid epimers. Overall, this study shows that drift tube ion mobility is a promising tool for improved separation of isomeric steroids. 相似文献
103.
Friedrich Müller C. Morton E. C. Gilbert Cobb H. M. Partridge M. R. Thompson H. Th. St. Britton W. S. Hughes Beatrice M. Wilson W. B. Pleass A. Roche J. Roche E. B. R. Prideaux F. T. Winfield K. Drewski Fr. L. Hahn A. Petit Erich Müller F. Ishikawa T. Murooka Sho-Chow Woo Don M. Yost M. Delépine O. Stelling R. Bennewitz W. Pugh B. Stehlik N. Allen N. H. Furman I. Tananaeff und L. Tronstad 《Fresenius' Journal of Analytical Chemistry》1933,95(1-3):48-57
Ohne Zusammenfassung 相似文献
104.
In modeling flow in open channels, the traditional finite difference/finite volume schemes become inefficient and warrant special numerical treatment in the presence of shocks and discontinuities. The numerical oscillations that arise by making use of a second‐ and higher‐order schemes require some additional smoothing mechanism. A characteristic feature of high‐resolution schemes lies in smooth capturing of the shock fronts. This paper provides a general formulation for a flux‐corrected transport algorithm to the one‐dimensional open channel flow equations. The preliminary results presented show that the present algorithm is an efficient, conservative and robust tool that can be easily coded. To demonstrate the robustness of the present formulation, results are compared with other published numerical results, experimental data and analytical solutions when available. In particular, a comprehensive study on the effect of the source term, dry bed, variable width channel, steep sloping channel and flow with mixed flow conditions (as in a hydraulic jump) has been carried out to test the efficacy of the present algorithm. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
105.
Frederick J. Troendle Christopher D. Reddick Richard A. Yost 《Journal of the American Society for Mass Spectrometry》1999,10(12):735-1321
A novel quadrupole ion trap mass spectrometer laser microprobe instrument with an external ionization source was constructed and used to investigate the matrix-assisted laser desorption/ionization (MALDI) detection of pharmaceutical compounds in intact tissue. In addition to MALDI, laser desorption coupled with chemical ionization (LD/CI) was investigated. MALDI, using 2,5-dihydroxybenezoic acid (DHB) as a matrix, was employed to detect the anticancer drug paclitaxel from a thin section of rat liver tissue which had been incubated in a solution of paclitaxel. The results of that experiment showed that the ability to perform tandem mass spectrometry (MS/MS) with the quadrupole ion trap was crucial in the identification of drug compounds at trace levels in the complex tissue matrix. MALDI MS/MS was then used to detect the presence of paclitaxel in a human ovarian tumor at a concentration of approximately 50 mg/kg. Finally, the drug spiperone was detected in incubated rat liver tissue at an approximate level of 25 mg/kg using LD/CI (no MALDI matrix). Again, the MS/MS capability of the quadrupole ion trap was crucial in the identification of the drug at trace levels in the complex tissue matrix. 相似文献
106.
A De A Mitra A Ray SR Banerjee M Sengupta A Chatterjee S Kailas HS Patel MG Betigiri SK Dutta 《Pramana》1999,53(3):549-552
In this paper, we report our measurements of back-angle oxygen and carbon particle yields from 16O+89Y, 12C+93Nb reactions forming the same compound nucleus 105Ag at the same excitation energy and spin distribution. We find anomalously large oxygen yield and entrance channel dependence
at high excitation energies from 16O+89Y reaction implying formation of a dinuclear orbiting complex. Possible connection between nuclear orbiting and fast fission
is also discussed. 相似文献
107.
W.B. Fretter W.R. Graves H.H. Bingham D.M. Chew B.Y. Daugeras A.D. Johnson J.A. Kadyk L. Stutte G.H. Trilling F.C. Winkelmann G.P. Yost D. Bogert R. Hanft F.R. Huson S. Kahn D. Ljung S. Pruss W.M. Smart 《Physics letters. [Part B]》1975,57(2):197-200
In 205 GeV/cπ?p inelastic interactions, negative particles with transverse momentum greater than 1.0 GeV/c moving forward in the center of mass outnumber similar positive particles by a factor of 3.7 to 1, greatly in excess of the corresponding ratio for small transverse momentum. The asymmetry is reversed in the backward direction. The forward asymmetry is most prominent in 2-, 4-, and 6-prong interactions, but both forward and backward asymmetries are also substantial for higher multiplicity interactions. 相似文献
108.
Discriminations of interaural phase differences 总被引:1,自引:0,他引:1
W A Yost 《The Journal of the Acoustical Society of America》1974,55(6):1299-1303
109.
H.H. Bingham W.B. Fretter W.R. Graves F.C. Porter L. Stutte G.P. Yost L.A. Dunn R. Harris H.J. Lubatti K. Moriyasu W.J. Podolsky 《Nuclear Physics B》1975,88(2):275-284
A broad threshold dπ+π? enhancement has been observed in π?d → dπ+π?π? at 15 GeV/c. It can be described by a model which assumes terms involving intermediate production, plus a Deck type enhancement. A simple calculation based on π±p data is successful in reproducing the main features of the data. 相似文献
110.
W A Yost R Patterson S Sheft 《The Journal of the Acoustical Society of America》1998,104(4):2349-2361
Iterated rippled noise (IRN) is generated by a cascade of delay and add (the gain after the delay is 1.0) or delay and subtract (the gain is -1.0) operations. The delay and add/subtract operations impart a spectral ripple and a temporal regularity to the noise. The waveform fine structure is different in these two conditions, but the envelope can be extremely similar. Four experiments were used to determine conditions in which the processing of IRN stimuli might be mediated by the waveform fine structure or by the envelope. In experiments 1 and 3 listeners discriminated among three stimuli in a single-interval task: IRN stimuli generated with the delay and add operations (g = 1.0), IRN stimuli generated using the delay and subtract operations (g = -1.0), and a flat-spectrum noise stimulus. In experiment 2 the listeners were presented two IRN stimuli that differed in delay (4 vs 6 ms) and a flat-spectrum noise stimulus that was not an IRN stimulus. In experiments 1 and 2 both the envelope and waveform fine structure contained the spectral ripple and temporal regularity. In experiment 3 only the envelope had this spectral and temporal structure. In all experiments discrimination was determined as a function of high-pass filtering the stimuli, and listeners could discriminate between the two IRN stimuli up to frequency regions as high as 4000-6000 Hz. Listeners could discriminate the IRN stimuli from the flat-spectrum noise stimulus at even higher frequencies (as high as 8000 Hz), but these discriminations did not appear to depend on the pitch of the IRN stimuli. A control experiment (fourth experiment) suggests that IRN discriminations in high-frequency regions are probably not due entirely to low-frequency nonlinear distortion products. The results of the paper imply that pitch processing of IRN stimuli is based on the waveform fine structure. 相似文献