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71.
72.
C. H. Shek J. K. L. Lai G. M. Lin Z. F. Tang 《Metallurgical and Materials Transactions A》1997,28(6):1337-1340
The fracture toughness J
Ic
(ρ) and fractal dimension D
f
of fractured surfaces of CuNiAl single crystal have been measured at temperatures in the range 20 °C to 120 °C, in which
thermoelastic martensitic transformation takes place. The parent phase has higher fracture toughness than the martensite phase
due to stress-induced transformation. The relationship between J
Ic
(ρ) and D
f
has been studied. It was found that log J
Ic
(ρ) is linearly related to D
f
if the failure involves a single mechanism. The slope of the plot may either be positive or negative for brittle or ductile
failure, respectively. The difference in the J
Ic
(ρ)-D
f
correlation can be understood in terms of the micromechanism of fracture. 相似文献
73.
Groups of algebraic integers used for coding QAM signals 总被引:2,自引:0,他引:2
Xue-dong Dong Cheong Boon Soh Gunawan E. Li-zhong Tang 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1998,44(5):1848-1860
Linear block codes over Gaussian integers and Eisenstein integers were used for coding over two-dimensional signal space. A group of Gaussian integers with 22n elements was constructed to code quadrature amplitude modulation (QAM) signals such that a differentially coherent method can be applied to demodulate the QAM signals. This paper shows that one subgroup of the multiplicative group of units in the algebraic integer ring of any quadratic number field with unique factorization, modulo the ideal (Pn), can be used to obtain a QAM signal space of 2p2n-2 points, where p is any given odd prime number. Furthermore, one subgroup of the multiplicative group of units in the quotient ring Z[ω]/(pn) can be used to obtain a QAM signal space of 6p2n-2 points; one subgroup of the multiplicative group of units in the quotient ring Z[i](pn) can be used to obtain a QAM signal space of 4p2n-2 points which is symmetrical over the quadrants of the complex plane and useful for differentially coherent detection of QAM signals; the multiplicative group of units in the quotient ring Z[ω]/(2n) can be used to obtain a QAM signal space of 3·22n-2 points, where i=√-1, ω=(-1+√-3)/2=(-1+i√3)/2, p is any given odd prime number, Z[i] and Z[ω] are, respectively, the Gaussian integer ring and the Eisenstein integer ring. These multiplicative groups can also be used to construct block codes over Gaussian integers or Eisenstein integers which are able to correct some error patterns 相似文献
74.
Yan Shuicheng Wang Huan Liu Jianzhuang Tang Xiaoou Thomas S. Huang 《Frontiers of Computer Science in China》2007,1(4):407-412
The techniques for image analysis and classification generally consider the image sample labels fixed and without uncertainties.
The rank regression problem studied in this paper is based on the training samples with uncertain labels, which often is the
case for the manual estimated image labels. A core ranking model is designed first as the bilinear fusing of multiple candidate
kernels. Then, the parameters for feature selection and kernel selection are learned simultaneously by maximum a posteriori
for given samples and uncertain labels. The provable convergency Expectation Maximization (EM) method is used for inferring
these parameters in an iterative manner. The effectiveness of the proposed algorithm is finally validated by the extensive
experiments on age ranking task and human tracking task. The popular FG-NET and the large scale Yamaha aging database are
used for the age estimation experiments, and our algorithm outperforms those state-of-the-art algorithms ever reported by
other interrelated literatures significantly. The experiment result of human tracking task also validates its advantage over
conventional linear regression algorithm.
A short version of this paper appeared in ICME07. 相似文献
75.
Nonlinear boundary element analysis provides a more accurate and detailing tool for the design of switched reluctance machines than conventional equivalent-circuit methods. Design optimization through more detailed analysis and simulation can reduce development and prototyping costs and time to market. Firstly, magnetic field modeling of an industrial switched reluctance machine by the boundary element method is reported in this paper. Secondly, performance prediction and dynamic simulation of motor and control design are presented. Thirdly, magnetic forces that cause noise and vibration are studied, to include the effects of motor and control design variations on noise in the design process. Testing of such a motor in the NEMA 215-Frame size is carried out to verify the accuracy of modeling and simulation 相似文献
76.
77.
用傅里叶变换红外扫描光致发光方法研究了Hg1-xCdxTe体单晶样品,该方法可直接得到HgCdTe晶片组分的二维平面分布,并可得到辐射复合在复合机制中所占比重的平面分布,以及晶体中非平衡载流子寿命的分布 相似文献
78.
79.
To investigate the prognostic factors of primary liver cancer (PLC) and improve the long-term results, 1,248 cases of PLC were analysed. Univariate analysis demonstrated that discovery approach, staging of PLC, original gamma-GPT, resection, radical resection, original AFP, tumor size, tumor number, and tumor capsule have very significant effects on prognosis of PLC (all P < 0.001); cirrhosis, HBsAg, local resection, and tumor embolus in portal vein were also significant difference (all P < 0.05); age, sex, original AFP, hepatitis, and differentiation of PLC cells were no significant difference (all P > 0.05). Multivariate analysis demonstrated that original gamma-GPT, radical resection, tumor size, and tumor number were the most significant prognostic factors (all P < 0.001). Some aspects improving long-term survival were discussed. 相似文献
80.
金刚石光电导探测器研制及在软X光测量中的初步应用 总被引:1,自引:0,他引:1
介绍了我们自己设计制造的天然Ⅱa型金刚石光导探测器的结构,原理,制造工艺,实验标定及其在ICF实验中软X光测量中的应用等。 相似文献