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971.
臭氧(O3)浓度通常被认为是一个地方污染水平的基准,所以其绝对值的准确性至关藿要.在差分光学吸收光谱技术(DOAS)对O3的测量过程中,光谱反演波段的选择可直接决定O3浓度的测量准确度.文章主要研究了在不同光谱波段O3特征吸收结构和差分光学厚度(D')的不同,在不同光谱波段O3浓度反演的干扰来源以及影响程度,确定了实际检测时大气消光对不同波段光强的影响,最后通过对多种污染物标准气体进行了同时临测,计算出标准气体在不同光谱分辨率不同O3浓度时的测量误差,确定了对O3的最适用光谱波段范围.在此波段既能够实现对痕量气体的准确定性定量,又能达到测量所需要的高灵敏度,强选择性和适用的时间分辨率. 相似文献
972.
A new concept and its methodology for studying human meridians are presented based on rigorous and scientific observation
on the objective existence of human meridians in view of biomedical optics. According to this methodology, the infrared radiant
characteristics of acupuncture meridians over human body and the optical transport properties of light propagating along the
meridian are reported. This study, thus, confirms the existence of acupuncture meridians, sheds new light on an approach to
investigation of human meridians and offers a new perspective in understanding the potential meridian functions such as energy
and information transfer and physiological regulation.
Supported by the National Key Basic Research Program of China (Grant No. 2006CB504505), the National Natural Science Foundation
of China (Grant Nos. 60578056 and 30572309), the Science Research Foundation of Ministry of Health & United Fujian Provincial
Health and Education Project for Tackling the Key Research of China (Grant No. WKJ2005-2-004), the Young Scientists and Technicians
Innovation Project of Fujian Province (Grant No. 2007F3026), and the Fund from Fujian Normal University (Grant No. 2008100218) 相似文献
973.
数字全息图在微电路检测、粒度分析、透明场测量等小孔径、小视场对象测量和细胞观测等显微测量方面有着广泛的应用前景。根据离轴数字全息图的频谱特点,提出采用复数滤波器,利用计算机及相关算法对离轴数字全息图进行滤波,消除其零级及共轭像,同时可以得到全息图的相位分布。讨论了复数滤波器的设计方法,给出了实验结果。为数字全息图的压缩、再现和相息图制作提供了方便。 相似文献
974.
975.
976.
977.
Chih T’sung Shih Zhi Wei Zeng Yin Cheng Chang Yao-Jen Lee Shiuh Chao 《Optical Review》2009,16(4):413-415
We provided a single-mode bent MOS-cross-section rib waveguide design with 0.9 dB/cm bending loss at 25 μm bending radius.
The peak position for the TE-like mode was tuned to the gate oxide around which the maximum amount of free carriers are accumulated
to optimize the free carrier dispersion effect. 相似文献
978.
F. F. Karpeshin M. B. Trzhaskovskaya J. Zhang 《The European Physical Journal A - Hadrons and Nuclei》2009,39(3):341-348
A mechanism of triggering the 12.7keV E3 transition, based on the new decay mode of the 31y isomer via resonance internal conversion and emission of a 1.4keV X-ray
quantum, is considered. Actually, this decay mode was observed previously in the decay of 45- and 46-fold ions of 125Te . For the purpose of triggering, the atomic radiative vertex has to be induced by resonance radiation. This mechanism makes
triggering by an order of magnitude more efficient than triggering a bare nucleus, and is achieved at a lower combination
frequency. An experiment is proposed for the direct observation of the new decay mode. This also offers a new way of resonance
scattering of these X-rays. Triggering through higher-lying 2573 and 2805keV states is also considered. The results are extended
to the general problem of triggering. The main obstacle for enhancing the efficiency is a high internal conversion rate. For
this reason, shape isomers with low multipole order --E1 , M1 , and with a high enough energy of triggering transition are of interest for triggering. The partial ionization of the outer
electrons will also help. The same recommendations hold for triggering isomers in laser-produced plasma. 相似文献
979.
F. Liang Y. H. Yang J. Wang 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(3):337-341
We propose an electrical scheme for the generation of a pure spin current without a charge current in a two-terminal device,
which
consists of a scattering region of a two-dimensional electron gas
(2DEG) with Rashba (R) and/or Dresselhaus (S) spin-orbit interaction (SOI)
and two normal leads. The SOI is modulated by a time-dependent gate
voltage to pump a spin current. Based on a tight-binding model and
the Keldysh Green’s function technique, we obtain the analytical
expression of the spin current. It is shown that a pure spin current
can be pumped out, and its magnitude could be modulated by
device parameters such as the oscillating frequency of the SOI, as
well as the SOI strength. Moreover, the spin polarisation direction of
the spin current could also be tuned by the strength ratio between
RSOI and DSOI. Our proposal provides not only a fully electrical means
to generate a pure spin current but also a way to control the spin
polarisation direction of the generated spin current. 相似文献
980.
S. Gleyzes A. El Amili R. A. Cornelussen P. Lalanne C. I. Westbrook A. Aspect J. Estève G. Moreau A. Martinez X. Lafosse L. Ferlazzo J. C. Harmand D. Mailly A. Ramdane 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(1):107-111
We study a Fabry-Perot cavity formed from a ridge waveguide on a AlGaAs substrate. We experimentally determined the propagation
losses in the waveguide at 780 nm, the wavelength of Rb atoms. We have also made a numerical and analytical estimate of the
losses induced by the presence of the gap which would allow the interaction of cold atoms with the cavity field. We found
that the intrinsic finesse of the gapped cavity can be on the order of F∼30, which, when one takes into account the losses
due to mirror transmission, corresponds to a cooperativity parameter for our system C∼1. 相似文献