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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A Dielectrophoretic Chip With a 3-D Electric Field Gradient 总被引:1,自引:0,他引:1
992.
The relationship between hydrogen concentration precipitated as hydride particles and ultrasonic parameters, such as velocity and attenuation, was examined in Zircaloy-4 samples for potential applications in the Non-Destructive Test Field. Different amounts of hydrogen (up to 517 ppm) were introduced in the samples by gaseous charging. Ultrasonic attenuation measurements were performed with compressive waves at frequencies of 10 and 30 MHz, and propagation velocity measurements were performed at 10 MHz. Ultrasonic velocity showed an approximately linear increase with hydrogen concentration and it could be used as an assessment parameter when the hydrogen level is high enough. Attenuation versus hydrogen concentration has been fitted by a logarithmic equation at 10 MHz. At 30 MHz a fluctuating behavior of the attenuation prevented measurement of the hydrogen concentration. 相似文献
993.
Eugene Spafford discusses the books that have been most influential in shaping his attitudes about security and privacy. 相似文献
994.
995.
I. V. Shcherbatenko E. P. Ivanova V. I. Surikov 《Chemical and Petroleum Engineering》2007,43(5-6):335-342
A method is proposed for calculating the optimum density of lattice of blades of screw pump impeller that ensures, for a given
cavitation margin (inlet pressure), the first critical condition on the partial cavitation characteristic of the pump. The
equations obtained can be used also to calculate the permissible cavitation margin of screw centrifugal and screw mixed-flow
pumps as well as of stand-alone screw impeller, provided the geometric and operating conditions of the screw are given.
__________
Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 6, pp. 29–33, June, 2007. 相似文献
996.
997.
RM Bionta G Blewitt CB Bratton D Casper A Ciocio R Claus M Crouch ST Dye S Errede GW Foster W Gajewski KS Ganezer M Goldhaber TJ Haines TW Jones D Kielczewska WR Kropp JG Learned JM LoSecco J Matthews HS Park LR Price F Reines J Schulz S Seidel E Shumard D Sinclair HW Sobel JL Stone L Sulak R Svoboda G Thornton van der Velde JC C Wuest 《Canadian Metallurgical Quarterly》1987,36(1):30-36
998.
999.
Verghese S. Hauser J.R. Wortman J.J. Kerns S.E. 《Electron Devices, IEEE Transactions on》1989,36(7):1311-1317
An analysis of forward I -V characteristics for Al Schottky contacts to polycrystalline thin films is presented. Experimental results for lateral structures with various n- doping levels show the expected twofold exponential characteristics representing a transition from electrode-limited to bulk-limited conduction. At higher doping levels the bulk-limited characteristic is not a perfect exponential. The thermionic emission theory has been modified to include crystallite resistivity between grain boundaries and successfully matches experimental data 相似文献
1000.