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921.
922.
亮度增益和等效背景照度是衡量像增强器性能的两个重要参数,针对这两个参数的测试要求,本文阐述像增强器亮度增益和等效背景测试仪的计算机模拟与结构设计。并利用研制的测试仪对多种型号的像增强器的亮度增益和等效背景照度进行了测试,给出并分析了测试结果。结果表明,本测试仪的计算机模拟和结构设计是合理有效的。 相似文献
923.
V Galli 《Analytica chimica acta》2003,482(1):37-45
It is of interest to measure the short chain organic acid content in natural latex serum, and capillary electrophoresis (CE) has proved to be a good tool for this study. However, for some acids, a higher sensitivity than that provided by the standard methods was needed. Therefore, a stacking effect was optimised and applied both for standards and real samples. Large-volume injection of sample solutions prepared in low conductivity matrices containing 50% acetonitrile (v/v) and 0.5% NaCl (w/v) gave the best results with enhancement factors over 17 and recoveries ranging from 83±14 to 122±4%. 相似文献
924.
925.
926.
A. B. Mirgorodskaya L. Ya. Zakharova F. G. Valeeva A. V. Zakharov L. Z. Rizvanova L. A. Kudryavtseva H. E. Harlampidi A. I. Konovalov 《Russian Chemical Bulletin》2007,56(10):2000-2007
The variation of the microscopic properties (surface potential, micropolarity, etc.) of the interface of cetyltrimethylammonium bromide micelles upon the addition of a background electrolyte or the nonionic
surfactant Triton X-100 decreases the rates of ion-molecular reactions, namely, alkaline hydrolysis of carboxylic acid esters
and tetracoordinate phosphorus acid esters, and results in the shift of acid-base equilibria.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1933–1940, October, 2007. 相似文献
927.
U. A. Yajnik 《Pramana》2004,63(6):1317-1330
We present an overview of the implications of the WMAP data for particle physics. The standard parameter set ∈, η and ξ characterising
the inflaton potential can be related to the power-law indices characterising deviation of the CMB spectrum from the scale
invariant form. Different classes of inflation potentials are in turn naturally associated with different unified schemes.
At present WMAP does not exclude any but a few simple unified models. In particular, hybrid models favoured by supersymmetric
unification continue to be viable. However future improvement in data leading to better determination of the ‘running’ of
power-law indices should help to narrow the possibilities for unified models. The main conclusion is that WMAP is consistent
with the paradigm of GUT scale (1016 GeV) inflation. 相似文献
928.
C. J. de Lima M. Simões L. SilveiraJr. F. L. Silveira A. B. Villaverde M. T. T. Pacheco 《Journal of Applied Spectroscopy》2007,74(1):107-114
This work demonstrates a multifiber optical catheter with bending control of the distal end, whose main use is to collect
Raman signal for biospectroscopy. Also, a method for fiber background subtraction is presented, allowing removal of fiber
emission peaks from gross Raman spectrum. The fiber optic catheter with seven fiber optics wrapped up in a resin and a biocompatible
flexible teflon tube has been modified to incorporate a mechanical device with gauntlet, which allows bending of the distal
extremity to access a desired location obeying the anatomy of the organ. The mechanical device (gauntlet) was built halfway
from the catheter proximal excitation tip, allowing the bending of the distal end of about 38 mm diameter. Dispersive Raman
spectra at 785 nm excitation wavelength from samples were measured without and with bending (from 120 mm decreasing to 14
mm) of the distal end of the catheter. An optical catheter without the gauntlet was used as a reference. Results demonstrated
that both catheters (with bending mechanism and standard one) had about the same Raman signal when the device was bent semicircularly
to 38 mm diameter (bending limit for the mechanism), with negligible implication to the Raman signal-to-noise relation (SNR)
from sample. When both catheters were bent in a full turn, the Raman signal decreased to about 40% when bending reached 14
mm diameter, mainly due to losses introduced by changes in the fiber total internal reflection. The background removal was
efficient, with minimum residual from fiber peaks. This optical catherer could be very useful in laser diagnosis and clinical
applications, introducing a way to control the fiber tip position and angle on the tissue or organ.
Published in Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 97–102, January–February, 2007. 相似文献
929.
复杂背景是影响场景文字自动定位算法性能的重要因素。为消除背景干扰,本文首先根据谱残差理论获取显著性区域,然后利用基于笔画特征的点对梯度方向差比例图与基于傅里叶谱统计特征的后验概率图取得显著性区域的文字置信图,最后借助图模型融合视觉显著性图、文字置信图与HSI颜色特征最终达到抑制自然图像背景并突出前景文字的效果。在ICDAR2011场景文字定位竞赛数据库与实验室场景中文数据库中的实验结果表明,本算法可较好的抑制自然图像中复杂背景,并有效提升算法的性能。 相似文献
930.
针对传统的目标徘徊检测方法在实时性和准确性等方面的不足,本文提出了一种基于目标轨迹分量曲线的行人徘徊检测算法。首先采用帧差法的背景模板建模方法来建立初始背景。然后用改进的结合背景差分的三帧差分法检测前景目标,通过Mean-shift算法对前景目标进行跟踪。最后将得到的运动轨迹做正交分解,根据根据轨迹的X,Y轴分量曲线来对徘徊行为进行识别。实验表明,该方法能够对几种典型的徘徊行为进行实时、精确判断,同时可以检测出其他复杂的徘徊行为,有较好的实时性和准确率。 相似文献