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111.
Calculation of surface wave motions due to a subsurface point force: an application of elastodynamic reciprocity 总被引:1,自引:0,他引:1
Achenbach JD 《The Journal of the Acoustical Society of America》2000,107(4):1892-1897
The elastodynamic reciprocity theorem for two time-harmonic elastodynamic states of the same body is used to determine the surface wave motions generated by a subsurface point load of arbitrary direction in an isotropic, homogeneous, elastic half-space. The actual surface wave motions due to the point load expressed in a suitably general form represent one of the states, while the other one is an appropriately selected auxiliary solution consisting of incoming and outgoing surface waves. A direct application of the reciprocity theorem yields the desired information on the generated surface wave motion. 相似文献
112.
113.
114.
Robert W. Bastian 《Journal of voice》1987,1(3)
Laryngeal image biofeedback (LIB) is a new therapeutic technique for selected patients with abnormal vocal production. In particular, patients with false vocal fold phonation or psychogenic aphonia/dysphonia who have failed traditional voice therapy have been found to respond to LIB. The apparatus and procedure used for this technique are presented along with suggested criteria for patient selection. 相似文献
115.
116.
Mass spectra of compounds of the kawain-type show significant ions, which are formed by unexpected hydrogen transfers. The spectra of deuterated kawains give information about the origin of the hydrogen atoms involved. 相似文献
117.
118.
Damoder P. Reddy Jan D. Achenbach 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1968,19(3):473-485
Zusammenfassung Ein halb-unendlicher dünner elastischer Stab wird einer monoton ansteigenden Störung am freien Ende unterworfen. Die unstetige Wellenbewegung für endliche Verzerrungen wird untersucht, und die Bedingungen zur Bildung von Stössen werden aufgestellt. Eine implizite Lösung für die Wellenbewegung im Gebiete einfacher Wellen wird mittels der Methode der Charakteristiken erhalten. Eine andere und explizite Lösung in diesem Gebiete wird gefunden durch Anwendung der Theorie sich fortpflanzender Diskontinuitätsflächen, als eine Taylor-Reihe um die Ankunftszeit der Wellenfront. Es wird gezeigt dass der Koeffizient des ersten Gliedes in der Entwicklung eine Lösung für eine homogene nichtlineare gewöhnliche Differentialgleichung ecster Ordnung darstellt. Die übrigen Koeffizienten befriedigen lineare, jedoch inhomogene gewöhnliche Differentialgleichungen mit veränderlichen Koeffizienten. Für den Fall einer rampenartigen Belastung und für Stossbildung an der Wellenfront wird für schwache Stösse durch Anwendung einer Methode von Friedrichs die Vereinigung von einfachen Wellen untersucht. Als Beispiel wird die Entlastung eines Stabes betrachtet, der einer anfänglichen Dehnung von 50% unterworfen ist. 相似文献
119.
Maas FE Achenbach P Aulenbacher K Baunack S Capozza L Diefenbach J Grimm K Imai Y Hammel T von Harrach D Kabuss EM Kothe R Lee JH Lorente A Lopes Ginja A Nungesser L Schilling E Stephan G Weinrich C Altarev I Arvieux J Collin B Frascaria R Guidal M Kunne R Marchand D Morlet M Ong S van de Wiele J Kowalski S Plaster B Suleiman R Taylor S 《Physical review letters》2004,93(2):022002
We report on a measurement of the parity-violating asymmetry in the scattering of longitudinally polarized electrons on unpolarized protons at a Q2 of 0.230 (GeV/c)(2) and a scattering angle of theta (e) = 30 degrees - 40 degrees. Using a large acceptance fast PbF2 calorimeter with a solid angle of delta omega = 0.62 sr, the A4 experiment is the first parity violation experiment to count individual scattering events. The measured asymmetry is A(phys)=(-5.44+/-0.54(stat)+/-0.26(sys))x10(-6). The standard model expectation assuming no strangeness contributions to the vector form factors is A(0) = (-6.30+/-0.43) x 10(-6). The difference is a direct measurement of the strangeness contribution to the vector form factors of the proton. The extracted value is G(s)(E) + 0.225G(s)(M) = 0.039+/-0.034 or F(s)(1) + 0.130F(s)(2) = 0.032+/-0.028. 相似文献
120.
Jonathan S. Schulze Timothy P. Lodge Christopher W. Macosko Jens Hepperle Helmut Münstedt Heike Bastian Dino Ferri David J. Groves Yong Hoon Kim Mike Lyon Thomas Schweizer Terry Virkler Erik Wassner Wim Zoetelief 《Rheologica Acta》2001,40(5):457-466
The transient uniaxial extensional viscosity η
e
of linear low density polyethylene (LLDPE) has been measured using the commercial Rheometric Scientific RME and the Münstedt
Tensile Rheometer in an effort to compare the performance of available extensional rheometers. The RME indicated a significant
strain hardening of the LLDPE, especially at a strain rate of 1 s−1. In contrast, the Münstedt rheometer showed the LLDPE to be only slightly strain hardening. This artificial strain hardening
effect in the RME resulted from the strain rate applied to the sample, determined from the sample deformation, being up to
20% less than the set strain rate. These results initiated a round-robin experiment in which the same LLDPE was tested on
several RMEs in various locations around the world. All but one of the RMEs indicated a deviation between set and applied
strain rates of at least 10%, especially at strain rates above 0.1 s−1. The strain rate deviation was found to depend strongly on the value of the basis length L
0
, and may result from the upper pair of belts not properly gripping the sample during extension. Thus visual inspection of
the sample deformation is necessary to determine the applied strain rate. The most accurate measurements of η
e
with respect to the strain rate deviation were obtained when the correct L
0
value and belt arrangement were used. A list of recommendations for running an RME test is provided. Future work focusing
on the fluid mechanics during the test may identify fully the cause of the strain rate deviation, but from a practical point
of view the problem can be corrected for in the determination of η
e
.
Received: 27 September 2000/Accepted: 5 February 2001 相似文献