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1.
W.P. RDZANEK JR 《Journal of sound and vibration》2002,249(2):307-323
The standardized mutual active and reactive sound power of a clamped plate, representing the energy aspect of the reciprocal interactions of two different in vacuo modes, has been computed. It was assumed that the vibrations are axisymmetric, elastic and time harmonic, the plate's transverse deflection is small as compared with the plate's size, and that the vibration velocity is small as compared with the acoustic wavenumber generated. The Kirchhoff-Love theory of a perfectly elastic plate was used. The integral formulae for the mutual sound power were transformed into their Hankel representations which made possible their subsequent computation. A closed path integral was used to express the integral in its Hankel representation to compute the mutual active sound power. The asymptotic stationary phase method was used to compute the two magnitudes, i.e., the mutual active and reactive sound power. The results obtained are the asymptotic formulae valid for the acoustically fast waves. The oscillating as well as the non-oscillating terms have been identified in the formulae to make possible their further separate analysis. The availability of the asymptotic formulae makes possible some fast numerical computations of the mutual sound power. Moreover, the formulae presented herein, together with those for the individual modes known from the literature, make a complete basis for further computations of the total sound power of the plate's damped and forced vibrations in fluid. 相似文献
2.
3.
Alves GA Amato S Anjos JC Appel JA Astorga J Bracker SB Cremaldi LM Darling CL Dixon RL Errede D Fenker HC Gay C Green DR Halling AM Jedicke R Karchin PE Kwan S Leuking LH Mantsch PM de Mello Neto JR Metheny J Milburn RH de Miranda JM da Motta Filho H Napier A Passmore D Rafatian A dos Reis AC Ross WR Santoro AF Sheaff M Souza MH Spalding WJ Stoughton C Streetman ME Summers DJ Takach SF Wallace A Wu Z 《Physical review D: Particles and fields》1994,49(9):R4317-R4320
4.
Alves GA Amato S Anjos JC Appel JA Astorga J Bracker SB Cremaldi LM Dagenhart WD Darling CL Dixon RL Errede D Fenker HC Gay C Green DR Jedicke R Karchin PE Kennedy C Kwan S Lueking LH de Mello Neto JR Metheny J Milburn RH de Miranda JM da Motta Filho H Napier A Passmore D Rafatian A dos Reis AC Ross WR Santoro AF Sheaff M Souza MH Spalding WJ Stoughton C Streetman ME Summers DJ Takach SF Wallace A Wu Z 《Physical review letters》1996,77(12):2388-2391
5.
Alves GA Amato S Anjos JC Appel JA Bracker SB Cremaldi LM Darling CL Dixon RL Errede D Fenker HC Gay C Green DR Jedicke R Kaplan D Karchin PE Kwan S Leedom I Lueking LH Luste GJ Mantsch PM de Mello Neto JR Metheny J Milburn RH de Miranda JM da Motta Filho H Napier A Rafatian A dos Reis AC Reucroft S Ross WR Santoro AF Sheaff M Souza MH Spalding WJ Stoughton C Streetman ME Summers DJ Takach SF Wu Z 《Physical review letters》1993,70(6):722-725
6.
Gas Phase Intercalation of Graphite by SbCl4F Gas Phase Intercalation of Graphite by SbCl4F using a two-zone technique is a method to prepare intercalation compounds of different stage index n in temperature range between 120 and 140°C. The reaction is a process of successive decrease of stage index. Increasing the reaction time, i. e. concentration, regions of pure stages alternate with two-phase regions. Intercalation compounds were characterized by X-ray technique, EPMA, and chemical methods. The compounds are stable in ordinary air, with aqueous HCl as well as KOH only pentavalent but not any trivalent antimony can be removed. The identity periods along c-axis in pure stages are Ic = 9.33 Å (n = 1), 12.72 Å (n = 2), 16.06 Å (n = 3) and 19.40 Å (n = 4). A (√7 × √ 7) 19.1° in-plane structure of intercalants was found. The uptake curve of mass with time reveals a discontinuity connected with formation of stage 2. Concave shape of curve during starting period at 120 and 125°C will be interpreted as a consequence of an induction time. From X-ray and EPMA studies it may be concluded that nucleation at the prismatic crystal edges controls the kinetics of reaction. Assuming a first order kinetics of filling the vacant sites, the same activation energy in case of formation of stage 1 and stage 2 have been determined approximately (97 and 102 kJ/mol). 相似文献
7.
H. Preiss 《无机化学与普通化学杂志》1972,389(3):280-292
The mass spectra of fifth group halids and some of their substitution products have been studied. Fragmentation processes, charge distributions as well as relative stabilities of fragment ions and double-charged ions are discussed. Appearance potentials have been measured and discussed, with reference to decomposition reactions and abundance considerations of fragment ions. In some cases polymeric ions were found in mass spectra. 相似文献
8.
Sigrid S. Dehmlow und Ivor L. Preiss 《Fresenius' Journal of Analytical Chemistry》1963,194(3):183-187
Zusammenfassung Es wird ein Trennverfahren für Silber und die drei Platinmetalle Ruthenium, Palladium und Rhodium beschrieben, das besonders für radiochemische Untersuchungen geeignet ist. In der angegebenen Reihenfolge wird das Ag als AgCl, das Ru gelöst in Tetrachlorkohlenstoff, das Pd als Dimethylglyoximkomplex und das Rh in wäßriger Phase oder als metallisches Rh bestimmt. Die Methode liefert in der kurzen Zeit von 10–12 min eine quantitative Halbmikrotrennung dieser Elemente mit ausgezeichneter Ausbeute und hohem Reinheitsgrad.
Die United States Atomic Energy Commission unterstützte die Arbeit.
Beurlaubt vom Chemischen Zentralblatt, Berlin, Deutschland.
Besonderen Dank sagen wir Frau Dr. I. M. Ladenbauer-Bellis für ihre Anregungen und Unterstützung und den Mitarbeitern des Elektronenbeschleunigers der Yale Universität für ihre Mitarbeit. 相似文献
Summary A quantitative, rapid method for the separation of silver and the three platinum metals palladium, ruthenium, and rhodium was developed for radiochemical studies and is shown to be suitable for semi-micro quantitative applications. The separation must be done in the following order: Ag is precipitated as AgCl, Ru is extracted into CCl4, Pd is precipitated as dimethylglyoxime complex, and Rh is determined either in aqueous phase or as Rh-metal. The method requires 10–12 minutes giving reproducable, quantitative separations of high chemical yield and high purity.
Die United States Atomic Energy Commission unterstützte die Arbeit.
Beurlaubt vom Chemischen Zentralblatt, Berlin, Deutschland.
Besonderen Dank sagen wir Frau Dr. I. M. Ladenbauer-Bellis für ihre Anregungen und Unterstützung und den Mitarbeitern des Elektronenbeschleunigers der Yale Universität für ihre Mitarbeit. 相似文献
9.
Binary organic-inorganic gels have been prepared by mixing a carbonaceous hydrosol and a Nb2O5 or Ta2O5 sol derived by hydrolysis of the alkoxides. The gels are pyrolyzed under an inert atmosphere into precursors in which carbon and the metal oxides are mixed very intimately. High temperature treatment converts the precursors into the cubic face centered carbides. The precursors as well as the carbides have been shown to be micro- and mesoporous materials. Measurements of nitrogen adsorption reveal a characteristic change of the shapes of the isotherms (Type I Type IV) and of the hysteresis loops (H4H2H1) during the thermal processes. Pore widening has been observed with rising temperature. The phenomena of crystallization, carbothermal reduction and sintering were found to control the pore shape and size. The results of the adsorption measurement correlate well with those of the thermoanalytical and X-ray diffraction studies.Dedicated to Professor Dr. rer.nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday 相似文献
10.
H. Buss H. W. Kohlschütter und M. Preiss 《Fresenius' Journal of Analytical Chemistry》1963,193(5):326-331
Zusammenfassung In Mitteilung I ist ein Verfahren für die maßanalytische Bestimmung von Phosphat in reinen Lösungen von Phosphorsäure oder Alkaliphosphaten beschrieben worden, bei dem Phosphat als Ammoniumzinkphosphat gefällt und nach der Auflösung von Ammoniumzinkphosphat Zink komplexometrisch titriert wird.In Mitteilung II wird dieses Verfahren auf technisch wichtige Produkte angewendet. Bei dieser Anwendung sind der maßanalytischen Bestimmung Aufschlüsse und Fällungen von Ammoniumphosphormolybdat bzw. Ammoniummagnesiumphosphat vorgeschaltet.Es werden Arbeitsvorschriften für die Überführung von Ammoniumphosphormolybdat bzw. Ammoniummagnesiumphosphat in Ammoniumzinkphosphat gegeben, das nach der Auflösung wie in Mitteilung I titriert werden kann.Die Leistungsfähigkeit des Verfahrens wird diskutiert. Es ist schneller als ein Verfahren mit gravimetrischer Endbestimmung. Es ist zur Serienanalyse geeignet.Die Untersuchung wurde mit Unterstützung der Deutschen Forschungsgemeinschaft durchgeführt.I. Mitteilung: H.Buss, H. W.Kohlschütter u. M.Preiss: diese Z.193, 264 (1963). 相似文献