The preparation of reference samples for refractoriness under load （ non-differential, with rising temperature） of refractories was discussed. According to features and application of reference samples, quartz glass...The preparation of reference samples for refractoriness under load （ non-differential, with rising temperature） of refractories was discussed. According to features and application of reference samples, quartz glass was chosen as a stand-by reference material for uniformity and stability tests. Then, the true value was fixed by gathering the testing results from many labs with stable testing levels and reliable testing results in China. The testing results from these labs were used for normality test by Shapiro-wilk method; and for abnormality value test by Grubbs method, for equal observation test by Cochran method. After confirming no abnormality values among the testing results from the labs. the average values of reference samples were calculated and the uncertainty was appraised. The results show that the standard value of reference samples is 1 386 ℃ and the expanded uncertainty is 12 ℃.展开更多
In order to measure differential cross sections of the 10B(n,α)7Li reaction induced by MeV neutrons using the forward-backward coincidence method, a thin film 10B sample was designed and the 10B atom number was deter...In order to measure differential cross sections of the 10B(n,α)7Li reaction induced by MeV neutrons using the forward-backward coincidence method, a thin film 10B sample was designed and the 10B atom number was determined with a reference 10B film sample. Alpha counts of the 10B(nth,α)7Li reaction from the 10B thin film and the reference sample were measured using a gridded ionization chamber and thermal neutrons, which were moderated and thermalized by paraffin from fast neutrons produced in D(d,n)3He reaction on a 4.5 MV Van de Graaff. The neutron flux was normalized by measuring the fission yield of a small 238U fission chamber.展开更多
In this paper, finite sample properties of virtual reference feedback tuning control are considered, by using the theory of finite sample properties from system identification. To design a controller in closed loop sy...In this paper, finite sample properties of virtual reference feedback tuning control are considered, by using the theory of finite sample properties from system identification. To design a controller in closed loop system structure, the idea of virtual reference feedback tuning is proposed to avoid the identification process corresponding to the plant model. After constructing one identification cost without any knowledge of plant model, the author derives one bound on the difference between the expected identification cost and its sample identification cost under the condition that the number of data points is finite. Also the correlation between the plant input and external noise is considered in the derivation of this bound. Furthermore, the author continues to derive one probability bound to quantify this difference by using some probability inequalities and control theory.展开更多
文摘The preparation of reference samples for refractoriness under load （ non-differential, with rising temperature） of refractories was discussed. According to features and application of reference samples, quartz glass was chosen as a stand-by reference material for uniformity and stability tests. Then, the true value was fixed by gathering the testing results from many labs with stable testing levels and reliable testing results in China. The testing results from these labs were used for normality test by Shapiro-wilk method; and for abnormality value test by Grubbs method, for equal observation test by Cochran method. After confirming no abnormality values among the testing results from the labs. the average values of reference samples were calculated and the uncertainty was appraised. The results show that the standard value of reference samples is 1 386 ℃ and the expanded uncertainty is 12 ℃.
基金Supported by National Natural Science Foundation of China (10575006 and 10811120014) and China Nuclear Data Center
文摘In order to measure differential cross sections of the 10B(n,α)7Li reaction induced by MeV neutrons using the forward-backward coincidence method, a thin film 10B sample was designed and the 10B atom number was determined with a reference 10B film sample. Alpha counts of the 10B(nth,α)7Li reaction from the 10B thin film and the reference sample were measured using a gridded ionization chamber and thermal neutrons, which were moderated and thermalized by paraffin from fast neutrons produced in D(d,n)3He reaction on a 4.5 MV Van de Graaff. The neutron flux was normalized by measuring the fission yield of a small 238U fission chamber.
基金supported by Jiangxi Provincial National Science Foundation under Grant No.20142BAB206020
文摘In this paper, finite sample properties of virtual reference feedback tuning control are considered, by using the theory of finite sample properties from system identification. To design a controller in closed loop system structure, the idea of virtual reference feedback tuning is proposed to avoid the identification process corresponding to the plant model. After constructing one identification cost without any knowledge of plant model, the author derives one bound on the difference between the expected identification cost and its sample identification cost under the condition that the number of data points is finite. Also the correlation between the plant input and external noise is considered in the derivation of this bound. Furthermore, the author continues to derive one probability bound to quantify this difference by using some probability inequalities and control theory.
