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991.
992.
The effects of ageing treatments on transformation temperatures, hardness, and precipitation kinetics in a Cu-14.2Zn-8.5Al (wt%) shape-memory alloy were investigated. Quench-ageing treatment temperatures varied from 100 to 500° C with times up to 200 h after the solution treatment. The martensitic transformation temperature, M
s, of the hot-rolled material was decreased from 55 to 51 °C by the solution treatment. The temperature hysteresis (A
f-M
f) was 50° C for the hot-rolled condition, but was reduced to 30° C after the solution treatment. The maximum hardness for material aged at 500° C was lower than that for that aged at 300 or 400° C. The apparent activation energy for hardness increase in this alloy was 110 kJ mol–1, compared with 72 kJ mol–1 for the similar copper-based shape-memory alloy Cu-21.2 Zn- 6.0 Al. The ordering temperatures for B2 and DO3 superlattices were in the neighbourhood of 480 and 260° C, respectively. The tensile ductility and yield strength of this alloy were significantly reduced by the ageing treatment at 400° C. 相似文献
993.
Parker J. Anthony Kenyon Robert V. Young Lwarence R. 《IEEE transactions on bio-medical engineering》1985,(1):28-36
Two methods of measuring ocular torsion from digital images of the eyes were developed and tested. One method measures torsion from the translation of two landmarks using a rectilinear coordinate system. The second method measures torsion from the translation of two landmarks using a polar coordinate system. The center for the polar sampling is the center of the pupil. After thresholding and filtering the images, landmark translation is measured from the interpolated peak in the normalized cross correlation of the reference landmark with the image. 相似文献
994.
Stable single-frequency fiber ring laser for 25-GHz ITU-T grids utilizing saturable absorber filter 总被引:1,自引:0,他引:1
Han Young Ryu Won-Kyu Lee Han Seb Moon Seung Kwan Kim Ho Suhng Suh Donghan Lee 《Photonics Technology Letters, IEEE》2005,17(9):1824-1826
A stable single-frequency fiber ring laser is proposed that operates in a single mode for more than an hour by incorporating unpumped erbium-doped fiber (EDF) as a saturable absorber filter and optimizing the length of EDF used as gain medium. This laser can be continuously tuned to 25-GHz spacing that precisely matches the ITU-T grids by temperature control of etalon filter. This laser had a signal-to-source spontaneous emission ratio higher than 70 dB, and lasing frequencies of 361 channels was matched to ITU-T grids with excellent flatness. Frequency offset from the ITU-T grid was less than 0.14 GHz. The linewidth and the relative intensity noise value was less than 1.3 kHz and 130 dB/Hz (above 250 kHz), respectively. 相似文献
995.
996.
997.
Bon Ki Koo Young Kyu Choi Chang Woo Chu Jae Chul Kim Byoung Tae Choi 《ETRI Journal》2005,27(2):235-238
A new mesh reconstruction scheme for approximating a surface from a set of unorganized 3D points is proposed. The proposed method, called a shrink‐wrapped boundary face (SWBF) algorithm, produces the final surface by iteratively shrinking the initial mesh generated from the definition of the boundary faces. SWBF surmounts the genus‐0 spherical topology restriction of previous shrink‐wrapping‐based mesh generation techniques and can be applied to any type of surface topology. Furthermore, SWBF is significantly faster than a related algorithm of Jeong and others, as SWBF requires only a local nearest‐point‐search in the shrinking process. Our experiments show that SWBF is very robust and efficient for surface reconstruction from an unorganized point cloud. 相似文献
998.
Such devices would be useful for monitoring line voltages in, for example, SF6 gas-insulated bus ducts. The theory of the devices is described and the results of tests on a laboratory prototype are presented. Furthermore, the design of a device monolithically integrating a capacitive divider and an integrated-optics Mach-Zehnder interferometer is proposed 相似文献
999.
Hyunjin Lim Sooyoun Park Hyeonsik Cheong Hyun-Min Choi Young Chool Kim 《Diamond and Related Materials》2010,19(10):1254-1258
We have performed low-temperature (8 K) photoluminescence (PL) measurements on 71 natural and 12 high-pressure-and-high-temperature (HPHT)-treated type IIa diamonds. The GR1, NV0, NV?, H4, and H3 defect center PL signals are compared. Some distinct differences in the PL lineshape, intensity, and appearance of side-band PL signals are observed. Furthermore, we processed 6 of the natural diamond samples with the HPHT treatment to investigate the effect of the treatment on the PL spectrum. By systematically analyzing the differences in the PL spectra, we developed a scheme to discriminate natural and HPHT-treated diamonds with 99% validity. 相似文献
1000.
Young Wook Jung Dong-Shig Oh Meejeong Kim Jae-Woo Park 《Nutrient Cycling in Agroecosystems》2010,87(2):261-275
LEACHN model is useful to describe the nitrogen transport and transformation in soil but requires many input parameters. A
sensitivity analysis can help to sort out the sensitive ones among many input parameters. A global sensitivity analysis technique,
Latin Hypercube One factor At a Time (LH-OAT) method, was applied to LEACHN model in this study. Only a few parameters were
found to be sensitive compared to many input parameters of the model from the sensitivity analysis. Using the results from
the sensitivity analysis, calibration and validation of LEACHN model for nitrate leaching was performed for the experimental
results from pot experiments that consisted of six types with different soil depth in mini-lysimeters and different fertilizer
additions. The results indicated that the use of LH-OAT method could help the facile field application of LEACHN model. Model
fitting could be improved by adopting current values in yearly crop parameters in validation. 相似文献