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951.
SJ Freedman DF Geesaman R Gilman MC Green RJ Holt HE Jackson ER Kinney R Kowalczyk C Marchand J Napolitano J Nelson DH Potterveld B Zeidman RE Segel T Tung D Beck G Boyd D Collins BW Filippone CE Jones J Jourdan RD McKeown R Milner R Walker PE Bosted Z Meziani R Minehart 《Canadian Metallurgical Quarterly》1993,48(4):1864-1878
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Lawrence N. Virgin 《Dynamical Systems: An International Journal》1989,4(1):56-70
An approach to studying the critical forcing parameters of an oscillator with a softening spring characteristic is developed. The harmonic response of the system is limited within a region of the phase plane, the boundary of which corresponds to a level of constant total energy for the underlying conservative system. This approach may be a useful conceptual aid in the understanding of the difficult problem of roll motion leading to capsize of a floating vessel. 相似文献
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Lawrence G. Tagg 《World Patent Information》1984,6(2):78-79
The paper describes an aggressive marketing campaign directed by Newcastle City Libraries to promote the value of patent information to companies in the North East of England. It records how the project is staffed and funded, the strategy employed in making contact with key executives in each firm and the benefits derived by those companies using patent information. 相似文献
958.
BACKGROUND: Doppler echocardiography is current tool for hemodynamic evaluation of mitral prosthetic heart valves. It's accepted that the area and the gradients by Doppler echocardiography are not influenced at rest by valvular type and valvular size. We evaluated the influence of valvular type, mechanical-biological, and size on exercise hemodynamic of normally-functioning mitral prosthesis. Thirty-seven patients with mitral prosthesis, mean age 56 +/- 10 years, underwent exercise Doppler echocardiography. Peak and mean prosthetic gradient were obtained at rest, during and at maximal exercise with a nonimaging transducer. Mechanical prosthesis were 23 and biological valves 14. Valvular size was less than 26 mm in 7 patients and more than 28 mm in 20 patients. Exercise increased the heart rate from 80 +/- 14 to 143 +/- 22 (p < 0.001), peak gradient from 11.4 +/- 4 to 26.1 +/- 7 mm Hg (p < 0.001) and mean gradient from 4.8 +/- 1 to 13.7 +/- 5 mm Hg (p < 0.001). We found similar peak (11.4 +/- 3 & 11.3 +/- 4) and mean gradient (3.4 +/- 1 & 2.9 +/- 0.7) at rest between mechanical and biological valves; at maximum exercise, peak (26 +/- 7 & 26 +/- 6) and mean gradient (13.9 +/- 6 & 13.2 +/- 4) were also similar. Prosthesis with > 28-mm-size compared with prosthesis < 26-mm-size showed minor peak gradient at second step (21.3 +/- 4 & 26.4 +/- 6, p < 0.05) and at peak exercise (25.4 +/- 7 & 29.8 +/- 8, ns). Hemodynamics on exercise using Doppler echocardiography was not influenced by valvular type (mechanical-biological) in normal mitral prosthesis. However, mitral prosthesis of small size showed worse on hemodynamics exercise than bigger ones. 相似文献
959.
Nutrition plays a significant role in preventing the incidence and prevalence of disease and more importantly, promoting health. Nutrition screening is an important tool used by nurses and dietitians to identify and assess clients at risk for nutritional compromise. 相似文献
960.
Solutions and parametric studies are presented for the buckling of rectangular plates whose axes of material orthotropy coincide with the axes of the plate. The results presented apply to homogeneous orthotropic plates, stiffened orthotropic plates, and laminated composite material plates having flexural orthotropy (i.e. single ply and multiply unidirectional, and symmetric cross-ply composite plates). The plates considered are subjected to uniform uniaxial compression and simply supported on the loaded edges. The boundary conditions are different on the two unloaded edges; one edge being free and the other edge being elastically restrained against rotation. Parametric studies showing the effect of the orthotropic properties of the plate materials, the plate aspect ratio, the rotational restraint of the one unloaded edge and the buckle half-wavelength are discussed. Results in the form of nondimensional buckling curves are given in terms of orthotropy ratios and in terms of properties of common unidirectionally reinforced composite material. The use of the solution in conjunction with experimental data to predict the edge rotational restraint coefficient for thin-walled composite material beams is described. 相似文献