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Ichiro?OdaEmail author Yukihisa?Wada Sadao?Takeuchi Ikuo?KonishiEmail author Yoshio?Tsunazawa 《Optical Review》2003,10(5):422-426
This paper describes a new near infrared (NIR) spectroscopic imager that has an expanded detection dynamic range intended for measurements with various transmitter-receiver (T-R) distances. Simultaneous multi-distance measurements for 48 points of the human forehead were performed to record brain activation by a mental test called digit span. Similarity Index (SI) analysis of 48 time-course curves was introduced for the evaluation of the result. A new mapping method toward depth direction is also shown for total hemoglobin and SI values. Simultaneous multi-distance measurements are useful for the brain functional analysis to distinguish depth variation. 相似文献
954.
L. Yang J. Chen H. Yang J. Dong 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,33(2):215-219
We have constructed four types single-wall carbon nanotube intramolecular junctions (IMJs) of (5,5)/(8,0), (5,5)/(10,0), (5,5)/(9,0)A, and (5,5)/(9,0)B along a common axis, and calculated their electronic and transport properties using a tight binding-based Green's function
approach that is particular suitable for realistic calculation of electronic transport property in extended system. Our results
show that quasi-localized states can appear in the metal/semiconductor heterojunctions ((5,5)/(8,0) and (5,5)/(10,0)junctions),
which is desirable for the design of a quantum device; and the conductance of M-M IMJs is very sensitive to the connectivity
of the matching tubes, certain configurations of connection completely stop the flow of electron, while others permit the
transmission of the current through the interface. These results may have implications for the device assembly and manipulation
process of all carbon nanotubes-based microelectronic elements.
Received 14 January 2003 / Received in final form 25 February 2003 Published online 4 June 2003
RID="a"
ID="a"e-mail: lfyzz@yahoo.com.cn 相似文献
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Jing Sun Fengchao Yu Tinggen Shen Yuequn Zhou Baoguo Yuan 《Journal of Russian Laser Research》2008,29(5):418-427
In this paper, we use the theory of spontaneous emission of two-level atoms embedded in photonic crystals. The unavoidable
existence of a localized field with a defect mode and its basic properties are confirmed, which enables one to study the inherent
laws of spontaneous emission from doped media. We combine the theory of spontaneous emission with numerical simulation for
studying stimulated emission in a doped localized field and conditions for increasing the emission. The inherent laws for
the cases where transmissivity is larger than unity and the negative imaginary part of the complex refractive index in doped
compound lattices appears are also studied. The analysis of two-dimensional nested rectangle photonic crystal fibers (PCFs)
with and without active impurities was performed using the finite-difference time-domain (FDTD) method. We find that, when
active impurities are introduced into photonic crystal fibers, the negative imaginary part of the complex refractive index
appears and the doped mode with high quality factor and great mode density occurs in the photonic forbidden band, thus amplifying
substantially the stimulated emission. 相似文献
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The nitrogen laser pumped dye laser output has been studied with emphasis on the behaviour of amplified spontaneous emission
(ASE) with respect to the tuning wavelength, pump energy, dyes and their concentration and solvents. Spectral spread of ASE
is narrower than fluorescence and its maximum is shifted towards the red side. However, lasing occurs beyond the ASE region.
ASE is small at high gain wavelength and increases at the edges of the gain curve. Laser energy is highest at the ASE peak
with minimum ASE present in the output. ASE is reduced with increased laser energy in the energy transfer dye lasers. 相似文献
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