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61.
L LinHui Ye YanLin Jiang DongXing Hua Hui Zheng Tao Li ZhiHuan Ge YuCheng Li XiangQing Lou JianLing Cao ZhongXin Song YuShou Xiao Jun Li QiTe Qiao Rui You HaiBo Chen RuiJiu Xu HuShan Wang JianSong Guo ZhongYan Zhang XueYing Li Chen Hu ZhengGuo Chen RuoFu Wang Meng Xu ZhiGuo Yue Ke Tang Bin Zang YongDong Zhang XueHeng Yao XiangWu Chen JinDa Bai Zhen 《中国科学:物理学 力学 天文学(英文版)》2011,54(1):136-140
Knockout reaction experiment was carried out by using the 6He beams at 61.2 MeV/u impinging on a CH2 target. The α core fragments at forward angles were detected in coincidence with the recoiled protons at larger angles. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism can be distinguished by the relation between the polar angles of the core fragments and the recoiled protons, respectively. It is demonstrated that the core knockout mechanism may result in some strong contamination to the real invariant mass spectrum.
相似文献62.
Zang L Macyk W Lange C Maier WF Antonius C Meissner D Kisch H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(2):379-384
Amorphous microporous metal oxides of titanium (AMM-Ti) modified with chlorides of PtIV, IrIV, RhIII, AuIII, PdII, CoII, and NiII have been prepared by the sol-gel method and characterized by various surface analytical methods. These hybrid AMM-Ti powders are catalysts for the photodegradation of 4-chlorophenol (4-CP) in aqueous solution when illuminated with visible (lambda > or = 400 or 455 nm) or UV (lambda > or = 335 nm) light. The initial rate depends on the dopant level and is highest at 3.0% Pt in the case of PtIV/AMM-Ti. When employed in a photoelectrochemical cell, the activity spectrum of the photocurrent extends downward to about 600 nm, as does the photodegradation of 4-CP. It is suggested that the metal salt acts as a redox-active chromophore, transmitting the photogenerated charges to the amorphous matrix. 相似文献
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We present results from a novel variational method for the study of beam propagation in a Kerr medium with nonlinear absorption. This new method combines the variational method and a nonlinear absorption equation and gives a concise expression for the combination. The results obtained with this method show good quantitative agreement with numerical solutions obtained with the finite-difference method. It is shown that the variational method takes much less time than a numerical simulation with the finite-difference method for analysis of beam propagation in a thick medium with nonlinear absorption and nonlinear refraction. The new method makes detailed analysis of beam propagation in a Kerr medium with nonlinear absorption very simple and fast. 相似文献
65.
Sze-Shiang Feng Zi Yao De-Pin Zhao De-Si Zang 《International Journal of Theoretical Physics》2001,40(9):1581-1593
We evaluate exactly both the nonrelativistic and relativistic fermion determinant in 2+1 dimensions in a constant background field at finite temperature. The effect of finite chemical potential is also considered. In both cases, the systems are decoupled into an infinite number of 1+1 fermions by Fourier transformation in the -variable. The total effective actions demonstrate nonextensiveness in the -dimension. 相似文献
66.
采用皮秒532nm 激光激发,研究了ZnWO4晶体的受激拉曼散射和本征荧光发射.在SRS光谱中观察到一级(558.7nm)和二级(588.6nm)斯托克斯光,线宽分别为130和77cm-1, 一级斯托克斯光的抽运阈值为6.8mJ.在532nm激光抽运下ZnWO4晶体的荧光光谱呈现出由能量为2.30,2.45和2.83eV的3个高斯分量组成的独特结构.光致发光表明晶体具有从400nm到650nm的宽带本征发光,其峰值波长为472.0nm,相应于钨氧之间的辐射跃迁.
关键词:
晶体
钨酸锌
受激拉曼散射
闪烁体 相似文献
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Combined neural network and reduced FRF techniques for slight damage detection using measured response data 总被引:2,自引:0,他引:2
Summary This paper deals with structural damage detection using measured frequency response functions (FRF) as input data to artificial
neural networks (ANN). A major obstacle, the impracticality of using full-size FRF data with ANNs, was circumvented by applying
a data-reduction technique based on principal component analysis (PCA). The compressed FRFs, represented by their projection
onto the most significant principal components, were used as the ANN input variables instead of the raw FRF data. The output
is a prediction of the actual state of the specimen, i.e. healthy or damaged. A further advantage of this particular approach
is its ability to deal with relatively high measurement noise, which is a common occurrence when dealing with industrial structures.
The methodology was applied to detect three different states of a space antenna: reference, slight mass damage and slight
stiffness damage. About 600 FRF measurements, each with 1024 spectral points, were included in the analysis. Six 2-hidden
layer networks, each with an individually-optimised architecture for a specific FRF reduction level, were used for damage
detection. The results showed that it was possible to distinguish between the three states of the antenna with good accuracy,
subject to using an adequate number of principal components together with a suitable neural network configuration. It was
also found that the quality of the raw FRF data remained a major consideration, though the method was able to filter out some
of the measurement noise. The convergence and detection properties of the networks were improved significantly by removing
those FRFs associated with measurement errors.
Received 9 March 2000; accepted for publication 12 December 2000 相似文献
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