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861.
This paper presents a method used to the numeral eddy current sensor modelling based on the genetic neural network to settle its nonlinear problem. The principle and algorithms of genetic neural network are introduced. In this method, the nonlinear model parameters of the numeral eddy current sensor are optimized by genetic neural network (GNN) according to measurement data. So the method remains both the global searching ability of genetic algorithm and the good local searching ability of neural network. The nonlinear model has the advantages of strong robustness, on-line modelling and high precision. The maximum nonlinearity error can be reduced to 0.037% by using GNN. However, the maximum nonlinearity error is 0.075% using the least square method. 相似文献
862.
Size-dependence of optical properties and energy relaxation in CdSe/ZnS quantum dots (QDs) were investigated by two-colour femtosecond (fs) pump-probe (400/800 nm) and picosecond time-resolved photoluminescence (ps TRPL) experiments. Pump-probe measurement results show that there are two components for the excited carriers relaxation, the fast one with a time constant of several ps arises from the Auger-type recombination, which shows almost particle sizeindependence. The slow relaxation component with a time constant of several decades of ns can be clearly determined with ps TRPL spectroscopy in which the slow relaxation process shows strong particle size-dependence. The decay time constants increase from 21 to 34 ns with the decrease of particle size from 3.2 to 2.1 nm. The room-temperature decay lifetime is due to the thermal mixing of bright and dark excitons, and the size-dependence of slow relaxation process can be explained very well in terms of simple three-level model. 相似文献
863.
新建HI-13串列加速器辐射防护联锁系统采用PLC自动化控制,增加与优化了原系统的联锁控制逻辑,在充分保证人员辐射安全的同时,使系统状态显示更直观,操作更方便. 相似文献
864.
L-Fuzzy拓扑空间中一种新型的强F仿紧性 总被引:8,自引:1,他引:8
本文引入一种新型的强F仿紧性─—Ⅲ型强F仿紧性,它是基于α-局部有限族概念提出的,这种α-局部有限族概念可用于刻划强F可数紧性。 相似文献
865.
The time-of-flight mass spectrum (TOFMS) relative to the resonant two-photon ionization of gas phase p- dichlorobenzene was obtained in the wavelength range of 240 - 250 nm by a home-made system. A special design was made to reduce the effect of memory on the inner wall of the sample inlet system suitable for the investigation of semi-volatile organic compound. In this wavelength range, p-dichlorobenzene molecules firstly absorbed one photon to be excited from the ground state ^1Ag(So) to the first excited state ^1B2u (S1), then absorbed another photon to be ionized. The relationship between the signal intensity of p-dichlorobenzene molecular ion C6H4^35Cl2^+ at 248-nm wavelength and the laser power was given. The 1.52 power index of C6H4^35Cl2^+ was a typical identification of the 3/2 power law. The relationship between the ion signal intensity of C6H4^35Cl2^+ and the sample concentration was close to a linear one in the ppm(V/V) range, which led to a detection limit of 125 ppb(V/V) for p-dichlorobenzene. 相似文献
866.
1.引言考虑非线性代数方程组这里, 为连续的对角映射,二者的导函数均存在,但并不一定连续.这类非线性代数方程组具有丰富的实际背景.譬如,Stefan问题和许多弱非线性椭圆型偏微分方程,就可归结为(1.1)的数值求解问题.根据方程组(1.1)的特殊结构,并利用矩阵多重分裂思想,文tZ]讨论了一类并行非线性Gauss-Seidel型迭代算法.这类算法具有很好的数值性质和较高的并行效率·在此基础上,运用松弛加速技术,文[8]进一步研究了一类并行多分… 相似文献
867.
868.
完全分配格上的正则性注记 总被引:1,自引:0,他引:1
In this note,the author gives some characterizations of regularity and complete regularity of topological molecular lattices,the shows that any regular and strong normal topological molecular lattice is completely regular;finally proves that every paracompact and regular topological molecular lattics is stronge normal,and further completely regular. 相似文献
869.
Li Huishi 《数学年刊B辑(英文版)》1994,15(4):463-468
It is proved that for a left Noetherian z-graded ring A,if every finitely generated graded A-module has finite projective dimension(i.e-,A is gr-regular)then every finitely generated A-module has finite projective dimension(i.e.,A is regular).Some applications of this result to filtered rings and some classical cases are also given. 相似文献
870.
分裂图的自同态幺半群的正则性 总被引:4,自引:0,他引:4
对自同态么半群正则的分裂图进行了刻划,从而关于分裂图回答了Knauer提出的一个公开问题[1]。 相似文献