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191.
J Grenner P Nilsson B Katbamna 《The Journal of the Acoustical Society of America》1989,86(6):2223-2228
Sixty guinea pigs were exposed to a steady-state broadband noise with a falling frequency spectrum. The sound-pressure level was varied between 96 and 117 dB SPL, and the duration of the exposure was varied from 3 to 12 h. After 4-5 weeks, the auditory thresholds were determined by electrocochleography at 14 frequencies, and the results were compared with a control group. With increasing sound-pressure level, the thresholds became elevated at all frequencies. The maximum threshold elevation also exhibited a slight shift toward higher frequencies. With increasing exposure time, the threshold elevations increased and shifted into the high-frequency region, whereas the low-frequency region was less affected. Linear regression analysis showed that the average threshold elevation between 1 and 20 kHz did not deviate from that predicted by the equal-energy hypothesis. However, the high-frequency loss at 5-20 kHz was very dependent on the exposure time, whereas the 1- to 4-kHz loss was not. There was no sign of any critical intensity with sudden increments in threshold elevation. 相似文献
192.
193.
Brenning N. Axnas I. Nilsson J.O. Eninger J.E. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1997,25(1):83-88
The requirements on preionization for the formation of spatially homogeneous pulsed avalanche discharges are examined. We derive two formulas which apply in the case of a slowly rising electric field, one which gives the required preionization density at breakdown, and one which gives the required preionization rate. These quantities are expressed as functions of the electrochemical properties of the gas, the neutral density, and the electric field rise time. We also treat the statistical effect that the electrons tend to form groups, in contrast to being randomly distributed in space, during the prebreakdown phase. This process is found to increase the required preionization rate significantly, typically by a factor of five for a discharge at atmospheric pressure 相似文献
194.
J. Persson U. Berzinsh T. Nilsson M. Gustavsson 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1992,23(1):67-70
The hyperfine structure of the metastable atomic states 5d 36s 2 4 P 3/2 and4 P 5/2 in181Ta has been studied using high resolution laser spectroscopy and laser radio-frequency double-resonance methods. 相似文献
195.
Solid-phase extraction for combinatorial libraries 总被引:3,自引:0,他引:3
Nilsson UJ 《Journal of chromatography. A》2000,885(1-2):305-319
Solid-phase extraction (SPE) has during the last three years emerged as a convenient method for the purification of compound libraries prepared by solution synthesis. The widespread use of SPE in combinatorial chemistry can be explained by straightforward SPE method development facilitated by the availability of numerous commercial SPE resins. High-speed automated SPE is readily accomplished by taking advantage of commercial laboratory robot systems. The present review summarizes and discusses advancements made in the use of different SPE resins and molecule tagging techniques for optimization of ion-exchange, reversed-phase, normal-phase and fluorous-phase SPE in combinatorial chemistry. 相似文献
196.
Sauer R Nilsson S Roentgen P Heuberger W Graf V Hangleiter A Spycher R 《Physical review. B, Condensed matter》1992,46(15):9525-9537
197.
Dr. Christian Pett Dr. Waqas Nasir Dr. Carina Sihlbom M. Sc. Britt‐Marie Olsson M. Sc. Vanessa Caixeta Dr. Manuel Schorlemer Dr. René P. Zahedi Prof. Göran Larson Dr. Jonas Nilsson Prof. Ulrika Westerlind 《Angewandte Chemie (International ed. in English)》2018,57(30):9320-9324
Distinct structural changes of the α2,3/α2,6‐sialic acid glycosidic linkages on glycoproteins are of importance in cancer biology, inflammatory diseases, and virus tropism. Current glycoproteomic methodologies are, however, not amenable toward high‐throughput characterization of sialic acid isomers. To enable such assignments, a mass spectrometry method utilizing synthetic model glycopeptides for the analysis of oxonium ion intensity ratios was developed. This method was successfully applied in large‐scale glycoproteomics, thus allowing the site‐specific structural characterization of sialic acid isomers. 相似文献
198.
Zinser M Humbert F Nilsson T Schwab W Blaich T Borge MJ Chulkov LV Eickhoff H Elze TW Emling H Franzke B Freiesleben H Geissel H Grimm K Guillemaud-Mueller D Hansen PG Holzmann R Irnich H Jonson B Keller JG Klepper O Klingler H Kratz JV Kulessa R Lambrecht D Leifels Y Magel A Mohar M Mueller AC Münzenberg G Nickel F Nyman G Richter A Riisager K Scheidenberger C Schrieder G Sherrill BM Simon H Stelzer K Stroth J Tengblad O Trautmann W Wajda E Zude E 《Physical review letters》1995,75(9):1719-1722
199.
In this work (1)H NMR self-diffusion experiments have been performed to determine the self-diffusion coefficients of n-octyl beta-d-glucoside and n-nonyl beta-d-glucoside in alpha-cyclodextrin and beta-cyclodextrin solutions at 25 degrees C. Two questions are addressed. The first concerns the general influence on nonionic surfactant transport properties when cyclodextrins are present in solution. The second question concerns the influence of surfactant-chain length and cyclodextrin cavity volume on the association constant. The self-diffusion coefficients of the alkyl glucosides, in cyclodextrin-containing solutions, depend on the cyclodextrin concentration on account of the formation of complexes. The cyclodextrin diffusion is only mildly influenced, since the complex has similar diffusion coefficients as the free cyclodextrin. There are some obstruction effects at the highest surfactant concentrations which decrease the cyclodextrin diffusion. A set of equations to model the self-diffusion coefficients of the surfactant and cyclodextrin was developed and is presented. On the basis of such equations, properties such as association constants, and micelle and complex diffusion coefficients can be estimated. 相似文献
200.
Ester hydrolysis by Sephadex-bound catalysts was studied in a flow-through system. Three different immobilized preparations were synthesized and used: histamine-, coimmobilized histamine-octylamine-, and octylamine-Sephadex; octylamine-Sephadex was used as a reference. Immobilization was carried out using water-soluble carbodiimide, which gave amide linkages between carboxymethyl Sephadex and the groups attached. It was found that the coimmobilized histamine-octylamine preparation was three times more efficient than immobilized histamine alone in the hydrolysis of the esterp-nitrophenylcaproate, whereas hardly any difference was found in the hydrolysis of the less hydrophobic substratep-nitrophenylacetate. We attribute this enhancement of the hydrolysis ofp-nitrophenylcaproate to local enrichment of the substrate on the histamine-octylamine matrix caused by the presence of hydrophobic octyl groups. 相似文献