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1.
Cross-axis synchronous flow-through coil planet centrifuge (type XLL). I. Design of the apparatus and studies on retention of stationary phase 总被引:1,自引:0,他引:1
The fourth prototype holds a pair of column holders in the lateral position at 15 cm from the center of the rotary shaft horizontally mounted on the rotary frame at 7.6 cm from the central axis of the apparatus. Using short coils of 2.6 mm I.D. PTFE (polytetrafluoroethylene) tubing with 7.6 cm and 24 cm helical diameters, retention of the stationary phase was measured in ten pairs of two-phase solvent systems under various experimental conditions. Satisfactory retention was obtained by choosing proper combinations of three factors, i.e., the direction of planetary motion, head-tail elution mode, and inward-outward elution mode. The polar butanol solvent systems showed excellent retention from 65 to 80% in the 7.6 cm helical diameter left-handed coil. 相似文献
2.
Virginia Trimble 《Brazilian Journal of Physics》2013,43(5-6):296-303
The first symposium on gravitational collapse and other aspects of relativistic astrophysics (Texas 1, in retrospect) was inspired by one idea—gravitational collapse of massive objects as an energy source—and one observational discovery—the large red shifts of optical counterparts of the quasistellar radiosources (soon quasars, even when radio quiet). Since that time, there has been fierce interplay at Symposia 2–26 between new ideas, new observations (or experiments if you are a physicist) and old ideas given new life. The talk and this paper explore a subset of the interactions. Texas has typically been a broad church, admitting nonstandard ideas and disputed data. Very approximately, half are still part of our universe of discourse. 相似文献
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Selden Y. Trimble 《Mathematische Zeitschrift》1969,109(2):112-114
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Trimble T Tang L Vasiljevic N Dimitrov N van Schilfgaarde M Friesen C Thompson CV Seel SC Floro JA Sieradzki K 《Physical review letters》2005,95(16):166106
Experimental results are presented for stress evolution, in vacuum and electrolyte, for the first monolayer of Cu on Au(111). In electrolyte the monolayer is pseudomorphic and the stress-thickness change is -0.60 N/m, while conventional epitaxy theory predicts a value of +7.76 N/m. In vacuum, the monolayer is incoherent with the underlying gold. Using a combination of first-principles based calculations and molecular dynamic simulations we analyzed these results and demonstrate that in electrolyte, overlayer coherency is maintained owing to anion adsorption. 相似文献
5.
A new, self-contained, proof of a coherence result for categories equipped with two symmetric monoidal structures bridged by a natural transformation is given. It is shown that this coherence result is sufficient for ω × ω-indexed family of iterated reduced bar constructions based on such a category. 相似文献
6.
Background
Tone languages such as Thai and Mandarin Chinese use differences in fundamental frequency (F0, pitch) to distinguish lexical meaning. Previous behavioral studies have shown that native speakers of a non-tone language have difficulty discriminating among tone contrasts and are sensitive to different F0 dimensions than speakers of a tone language. The aim of the present ERP study was to investigate the effect of language background and training on the non-attentive processing of lexical tones. EEG was recorded from 12 adult native speakers of Mandarin Chinese, 12 native speakers of American English, and 11 Thai speakers while they were watching a movie and were presented with multiple tokens of low-falling, mid-level and high-rising Thai lexical tones. High-rising or low-falling tokens were presented as deviants among mid-level standard tokens, and vice versa. EEG data and data from a behavioral discrimination task were collected before and after a two-day perceptual categorization training task.Results
Behavioral discrimination improved after training in both the Chinese and the English groups. Low-falling tone deviants versus standards elicited a mismatch negativity (MMN) in all language groups. Before, but not after training, the English speakers showed a larger MMN compared to the Chinese, even though English speakers performed worst in the behavioral tasks. The MMN was followed by a late negativity, which became smaller with improved discrimination. The High-rising deviants versus standards elicited a late negativity, which was left-lateralized only in the English and Chinese groups.Conclusion
Results showed that native speakers of English, Chinese and Thai recruited largely similar mechanisms when non-attentively processing Thai lexical tones. However, native Thai speakers differed from the Chinese and English speakers with respect to the processing of late F0 contour differences (high-rising versus mid-level tones). In addition, native speakers of a non-tone language (English) were initially more sensitive to F0 onset differences (low-falling versus mid-level contrast), which was suppressed as a result of training. This result converges with results from previous behavioral studies and supports the view that attentive as well as non-attentive processing of F0 contrasts is affected by language background, but is malleable even in adult learners. 相似文献7.
RD Harris WS Baker Van Stipdonk MJ RM Crooks EA Schweikert 《Rapid communications in mass spectrometry : RCM》1999,13(14):1374-1380
A suite of keV polyatomic or 'cluster' projectiles was used to bombard unoxidized and oxidized self-assembled monolayer surfaces. Negative secondary ion yields, collected at the limit of single ion impacts, were measured and compared for both molecular and fragment ions. In contrast to targets that are orders of magnitude thicker than the penetration range of the primary ions, secondary ion yields from polyatomic projectile impacts on self-assembled monolayers show little to no enhancement when compared with monatomic projectiles at the same velocity. This unusual trend is most likely due to the structural arrangement and bonding characteristics of the monolayer molecules with the Au(111). Copyright 1999 John Wiley & Sons, Ltd. 相似文献
8.
Michel Belley Effiette Sauer Daniel Beaudoin Petar Duspara Laird A. Trimble Pascal Dubé 《Tetrahedron letters》2006,47(2):159-162
Catalytic hydrogenation of (2-nitrophenyl)acetonitriles bearing an electron-withdrawing substituent α to the nitrile, using Pd/C and (Ph3P)4Pd, affords N-hydroxy-2-aminoindoles in good to excellent yields. (Ph3P)4Pd decreases the reduction rate of the intermediate hydroxylamine and acts as a catalyst during the cyclization onto the nitrile. 相似文献
9.
G. Prange E. O. Whittier C. S. Trimble E. Pijanowski R. Lucentini Elsa Drago S. Bezzi S. Sacconi J. Großfeld B. W. Hammer C. R. Barnicoat M. Baumann A. Iwanowa A. Ljutenberg T. Dudkina H. Schmalfuß O. Benecke A. Koss Ciusa Waller H. Toms R. T. M. Haines J. C. Drummond N. Evers A. G. Jones W. Smith I. Tveraaen Alf Klem W. Leithe R. Strohecker A. F. H. Ward und G. D. France 《Fresenius' Journal of Analytical Chemistry》1937,108(7-8):292-304
Ohne Zusammenfassung 相似文献
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