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This work described the assignment of purity values to six carbohydrate certified reference materials, including glucose, fructose, galactose, lactose, xylose and sucrose, according to the ISO Guides 34 and 35. The CRMs' purity values were assigned based on the weighted average of quantitative nuclear magnetic resonance method and mass balance approach with high resolution liquid chromatography - evaporative light scattering detection. All the six CRMs with following value amount fractions: glucose (GBW10062) at a certified purity P ± U (k = 2) of (0.99 ± 0.005)%; fructose (GBW10063) at (0.99 ± 0.005)%; galactose (GBW10064) at (0.99 ± 0.007)%; lactose (GBW10065) at (0.99 ± 0.008)%; xylose (GBW10066) at (0.99 ± 0.007)% and sucrose (GBW10067) at (0.99 ± 0.008)%, respectively were certified. The homogeneity of the CRMs was determined by an in-house validated liquid chromatographic method. Potential degradation during storage was also investigated and a shelf-life based on this value was established. © 2013 Elsevier Ltd. All rights reserved. Source

Yuan Z.,China Institute of Metrology
Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument

Aiming at the problems of actual temperature measurements and the defects of classical radiance thermometry theory, the concept of generalized effective radiance temperature (GERT) is proposed, which adopts gray-body as the reference radiator. Furthermore, the relationship between the "subjective" characteristic (integral GERT) measured by band-pass radiation thermometer and the "objective" characteristic of surface effective radiation (GERT) is exposited with the equivalent wavelength theory. The general characteristics of the GERT and its conversion relationship with the generalized, effective and classical radiance temperatures are summarized. GERT theory is a development of the classic apparent temperature theory with blackbody as the reference radiator, which can express and explain the practical measurement results of radiation thermometers in theory, including the measurement results of the radiation thermometers with the correction function of instrument emissivity. Source

Zhang Z.,China Institute of Metrology
Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument

In comparison with traditional measurement standards, quantum measurement standards have a series of outstanding advantages, such as high accuracy and reproducibility at different laboratories, and etc. Therefore, quantum measurement standards developed rapidly in the passed forty years. At present, the quantum standards for length, time and electrical quantities have been established and the measurement accuracy was improved by several magnitudes. This paper describes the current achievements of the quantum standards for length, time and electrical quantities, and expatiates several suggested solutions to the quantum standard for mass (the difficult one) in international metrology field and the related progress. In the new century, quantum measurement standards will be developed and improved further. Source

Yang B.,China Institute of Metrology
Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering

In order to deal with the problem that empirical model of by-product gas consumption in iron and steel enterprises cannot accurately predict the by-product gas consumption, the analysis of by-product consumption user and its characteristics is carried out. Support vector machine is used to classify the by-product gas consumption. It combines Powell calculation, simulated annealing arithmetic calculation, and support vector regression machine (SVRM), a model of PSA (Powell simulated annealing)-SVRM to predict the by-product gas consumption has been established. By-product gas consumption data in some iron and steel enterprises are used in the model. The results show that the prediction accuracy for sintering, steelmaking and continuous casting processes is 94.8%, 94.9% and 100%, respectively, with the relative mean error of 2.5%, 2.8% and 2.1%, respectively, which indicates that this PSA-SVRM model is suitable to prediction of the by-product gas consumption. Wilcoxon sign rank test proves the effectiveness of PSA-SVRM model. Source

China Institute of Metrology and Zhejiang University | Date: 2012-08-16

The infrasound generating device based on a displacement-feedback type vibration exciter comprises a displacement-feedback type vibration exciter system, an infrasound generating chamber (

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