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91.
Keisuke Yoshiki Hiroki Azuma Kazuhiko Yoshioka Mamoru Hashimoto Tsutomu Araki 《Optical Review》2005,12(5):415-419
We have investigated the fluorescence lifetime properties of 8 calcium ion probes, calcium-green-1, calcium green-2, calcium
green-5N, calcium orange, oregon green 488 BAPTA-6F, fluo-3, fluo-4, and fluo-5N. We found that the decay time of calcium
green-5N varied more sensitively with calcium concentration than calcium green-1 which was known to be a highly sensitive
probe. We have also found that the center of observable range of calcium concentration by fluorescence lifetime measurement
is lower than that by fluorescence intensity measurement. 相似文献
92.
We have developed a fetal movement monitoring system based on small displacement measurement of internal tissues. When ultrasonic pulses are transmitted to the fetus, the reflected ultrasonic waves which have a Doppler frequency shift due to the fetal movements are detected by using an ultrasonic pulsed Doppler technique. In this paper, we propose a displacement measurement method for internal tissues which is based on the Doppler signal digital detection technique. In the method, the received ultrasonic RF signals are sampled with a sampling frequency of four times higher than the centre frequency of the ultrasonic waves; the Doppler frequency shift signals are derived using digital signal processing. From the detected signals, the internal displacements are estimated using the arc-tangent method. The basic algorithm of the detection method has already been used in the area of blood flow sensing, however, we apply the algorithm to the displacement measurement of internal tissues. The comparison between the proposed method and the conventional method is presented. The fetal movement quantitative monitoring system based on the method which has been constructed is shown. 相似文献
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97.
Yoshiki Tsujino 《Infrared Physics & Technology》2010,53(1):50-60
As an approach for analyzing an uncooled infrared bolometer imager, a method is introduced which supposes that a thermal system is built into the infrared radiation detection mechanism. In this analysis, the bi-directional radiation energy flows between two thermal elements are considered and a radiation thermal conductance between them is defined. Based on the values of the radiation thermal conductances and conventional material thermal conductance, an equivalent thermal circuit for a bolometer detector element is extracted. Calculations were carried out using software written in visual C++. The analysis shows a Noise Equivalent Temperature Difference (NETD) of 50 mK is obtained as a typical value, assuming that no additional noise other than temperature fluctuation noise exists, and that the NETD becomes better as the system time constant built into the equivalent thermal circuit increases. 相似文献
98.
Miao J Chen CC Song C Nishino Y Kohmura Y Ishikawa T Ramunno-Johnson D Lee TK Risbud SH 《Physical review letters》2006,97(21):215503
In combination of direct phase retrieval of coherent x-ray diffraction patterns with a novel tomographic reconstruction algorithm, we, for the first time, carried out quantitative 3D imaging of a heat-treated GaN particle with each voxel corresponding to 17 x 17 x 17 nm3. We observed the platelet structure of GaN and the formation of small islands on the surface of the platelets, and successfully captured the internal GaN-Ga2O3 core shell structure in three dimensions. This work opens the door for nondestructive and quantitative imaging of 3D morphology and 3D internal structure of a wide range of materials at the nanometer scale resolution that are amorphous or possess only short-range atomic organization. 相似文献
99.