Measurement uncertainty plays an important role in laser tracking measurement analyses. In the present work, the guides to the expression of uncertainty in measurement(GUM) uncertainty framework(GUF) and its supplemen...Measurement uncertainty plays an important role in laser tracking measurement analyses. In the present work, the guides to the expression of uncertainty in measurement(GUM) uncertainty framework(GUF) and its supplement, the Monte Carlo method, were used to estimate the uncertainty of task-specific laser tracker measurements. First, the sources of error in laser tracker measurement were analyzed in detail, including instruments, measuring network fusion, measurement strategies, measurement process factors(such as the operator), measurement environment, and task-specific data processing. Second, the GUM and Monte Carlo methods and their application to laser tracker measurement were presented. Finally, a case study involving the uncertainty estimation of a cylindricity measurement process using the GUF and Monte Carlo methods was illustrated. The expanded uncertainty results(at 95% confidence levels) obtained with the Monte Carlo method are 0.069 mm(least-squares criterion) and 0.062 mm(minimum zone criterion), respectively, while with the GUM uncertainty framework, none but the result of least-squares criterion can be got, which is 0.071 mm. Thus, the GUM uncertainty framework slightly underestimates the overall uncertainty by 10%. The results demonstrate that the two methods have different characteristics in task-specific uncertainty evaluations of laser tracker measurements. The results indicate that the Monte Carlo method is a practical tool for applying the principle of propagation of distributions and does not depend on the assumptions and limitations required by the law of propagation of uncertainties(GUF). These features of the Monte Carlo method reduce the risk of an unreliable measurement of uncertainty estimation, particularly in cases of complicated measurement models, without the need to evaluate partial derivatives. In addition, the impact of sampling strategy and evaluation method on the uncertainty of the measurement results can also be taken into account with Monte Carlo method, which plays a guiding role in measurement planning.展开更多
Several task-specific ionic liquids（TSILs） with weak alkalinity have been designed based on tetraalkyl-ammonium cation and L-alanine anion([N<sub>2222</sub>][L-Ala]) for the CO<sub>2</sub> ab...Several task-specific ionic liquids（TSILs） with weak alkalinity have been designed based on tetraalkyl-ammonium cation and L-alanine anion([N<sub>2222</sub>][L-Ala]) for the CO<sub>2</sub> absorption.[N<sub>2222</sub>][L-Ala]has been chosen as a green and efficient activator for methyldiethanolamine（MDEA）.The densities,viscosities and absorption properties of the equimolar[N<sub>2222</sub>][L-Ala]-MDEA blended absorbents were investigated.Low viscosity and density values support the idea that blended absorbents are preferred in the industrial applications.[N<sub>2222</sub>][L-Ala]-MDEA behave similarly to the aqueous counterparts but offer more advantages,such as large absorption capacities,fast absorption rate and relatively low damage to the environment.展开更多
基金Project(51318010402)supported by General Armament Department Pre-Research Program of China
文摘Measurement uncertainty plays an important role in laser tracking measurement analyses. In the present work, the guides to the expression of uncertainty in measurement(GUM) uncertainty framework(GUF) and its supplement, the Monte Carlo method, were used to estimate the uncertainty of task-specific laser tracker measurements. First, the sources of error in laser tracker measurement were analyzed in detail, including instruments, measuring network fusion, measurement strategies, measurement process factors(such as the operator), measurement environment, and task-specific data processing. Second, the GUM and Monte Carlo methods and their application to laser tracker measurement were presented. Finally, a case study involving the uncertainty estimation of a cylindricity measurement process using the GUF and Monte Carlo methods was illustrated. The expanded uncertainty results(at 95% confidence levels) obtained with the Monte Carlo method are 0.069 mm(least-squares criterion) and 0.062 mm(minimum zone criterion), respectively, while with the GUM uncertainty framework, none but the result of least-squares criterion can be got, which is 0.071 mm. Thus, the GUM uncertainty framework slightly underestimates the overall uncertainty by 10%. The results demonstrate that the two methods have different characteristics in task-specific uncertainty evaluations of laser tracker measurements. The results indicate that the Monte Carlo method is a practical tool for applying the principle of propagation of distributions and does not depend on the assumptions and limitations required by the law of propagation of uncertainties(GUF). These features of the Monte Carlo method reduce the risk of an unreliable measurement of uncertainty estimation, particularly in cases of complicated measurement models, without the need to evaluate partial derivatives. In addition, the impact of sampling strategy and evaluation method on the uncertainty of the measurement results can also be taken into account with Monte Carlo method, which plays a guiding role in measurement planning.
基金supported by the National Natural Science Foundation (21076101)Technological Support Project of Jiangsu Province(SBE 201000600)
文摘Several task-specific ionic liquids（TSILs） with weak alkalinity have been designed based on tetraalkyl-ammonium cation and L-alanine anion([N<sub>2222</sub>][L-Ala]) for the CO<sub>2</sub> absorption.[N<sub>2222</sub>][L-Ala]has been chosen as a green and efficient activator for methyldiethanolamine（MDEA）.The densities,viscosities and absorption properties of the equimolar[N<sub>2222</sub>][L-Ala]-MDEA blended absorbents were investigated.Low viscosity and density values support the idea that blended absorbents are preferred in the industrial applications.[N<sub>2222</sub>][L-Ala]-MDEA behave similarly to the aqueous counterparts but offer more advantages,such as large absorption capacities,fast absorption rate and relatively low damage to the environment.
