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61.
A. A. Vertiy S. P. Gavrilov 《International Journal of Infrared and Millimeter Waves》1997,18(9):1761-1781
Tomographycal methods of image reconstruction of two-dimensional objects, surfaces or subsurface regions in millimeter wavelengths
band are suggested and considered. Experimental images obtained using antennas and waveguiding lines of different types and
radiation frequencyf≈33÷35GHz are represented. Volumetric dielectric objects and plane-parallel ferrite (or dielectric) plates distributed in
free space or in homogeneous dielectric medium have been taken as objects under investigation.
It is shown that in the frequency band under consideration, the images of investigated objects with characteristic dimensionA≈2λ÷7λ may be obtained by first-order diffraction tomography method (Born, Rytov or high frequency approximation of the first-order
for electromagnetic field). 相似文献
62.
63.
蚊蝇杀灭器及其发射光谱分析 总被引:1,自引:0,他引:1
文章首先介绍了蚊蝇杀灭器在佛山市两个单位的职工饭堂厨房和会议室或值班室的试验情况。然后围绕文中四个图说明了下面四个问题:一,展示了进行光谱分析的测量装置。二,将蚊蝇杀灭器黑光灯的发射光谱和日用荧光灯发射光谱作分析比较。三,指出黑光灯也是一种荧光灯,说明了它的发光机理。四,展示了国外一种高效黑光灯的发射光谱,它是用活性铈钙磷酸脂做荧光涂料,我们进一步深入探讨了这种黑光灯的发光机制,并介绍了它的其他用 相似文献
64.
Bin Zhu 《Journal of Algebraic Combinatorics》2008,27(1):35-54
We give a quiver representation theoretic interpretation of generalized cluster complexes defined by Fomin and Reading. Using
d-cluster categories defined by Keller as triangulated orbit categories of (bounded) derived categories of representations
of valued quivers, we define a d-compatibility degree (−∥−) on any pair of “colored” almost positive real Schur roots which generalizes previous definitions on the noncolored case
and call two such roots compatible, provided that their d-compatibility degree is zero. Associated to the root system Φ corresponding to the valued quiver, using this compatibility relation, we define a simplicial complex which has colored almost
positive real Schur roots as vertices and d-compatible subsets as simplices. If the valued quiver is an alternating quiver of a Dynkin diagram, then this complex is
the generalized cluster complex defined by Fomin and Reading.
Supported by the NSF of China (Grants 10471071) and by the Leverhulme Trust through the network ‘Algebras, Representations
and Applications’. 相似文献
65.
Michael Rathjen 《Mathematical Logic Quarterly》2008,54(1):83-97
Constructive set theory started with Myhill's seminal 1975 article [8]. This paper will be concerned with axiomatizations of the natural numbers in constructive set theory discerned in [3], clarifying the deductive relationships between these axiomatizations and the strength of various weak constructive set theories. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
66.
利用DirectDraw模块进行快速动画设计,重点对其直接操纵显存的特性和用后缓冲区实现动画中背景擦除和重绘的技巧进行探索,并结合火焰字的实例说明本文提出的方法是Win95下开发动画软件的一种切实可行的方法. 相似文献
67.
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69.
浙产山胡椒根挥发油化学成分的研究 总被引:1,自引:0,他引:1
采用水蒸汽蒸馏法提取挥发油,气相色谱-质谱联用法结合计算机检索对浙产山胡椒根挥发油的化学成分进行分析和鉴定,用气相色谱面积归一法计算各组分的相对百分含量。从山胡椒根的挥发油中,分析并鉴定出17种化合物。主要含1,2,3,3a,4,5,6,7-八氢-1,4-二甲基-7-(1-甲基乙烯基)-奥艹、4,6,6-三甲基-2-(3-甲基-1,3-丁二烯基)-3-氧杂环-辛烷、愈创木醇、1,2,3,5,6,7,8,8a-八氢-1,4-二甲基-7-(1-甲基乙烯基)-奥艹,它们占挥发油总量的84.75%。 相似文献
70.
This paper reports the theoretical study of combining Z-scan technique with Gauss-Bessel (GB) beams beside a phase object (PO) to measure the third-order nonlinear susceptibility components.By using this method,the sign of refractive index which depends on the shape of the close aperture Z-scan curve can be easily determined.Meanwhile,the magnitude of nonlinear coefficients can also be deduced by theoretical fit.The proposed method is advantageous for high sensitivity and imposes a lower stress in the cases of fragile materials,since small pulse energy is enough for the measurement of nonlinear coefficients.Predictions of the models are compared with Gaussian Z-scan measurement and GB Z-scan measurement.By using GB beams with a PO,the sensitivity of Z-scan measurements is found to be a factor of over 60 times greater than for Gaussian beams and 2 times greater than for Gaussian-Bessel beams. 相似文献