A novel hydrocyclone with guide vanes, named as axial hydrocyclone(AHC), is designed to tackle the problem of oil–water separation faced by most mature oilfields. Optimal design of the AHC is carried out by using num...A novel hydrocyclone with guide vanes, named as axial hydrocyclone(AHC), is designed to tackle the problem of oil–water separation faced by most mature oilfields. Optimal design of the AHC is carried out by using numerical methods. The effects of guide vanes, cone angle, tapered angle and overflow pipe on the oil–water separation are discussed in this paper. The results show that a double swirling flow is generated in the tapered section where oil–water separation occurs. Both the cylindrical and the tapered section have important influences on AHC performance. On the basis of single factor results, response surface methodology is employed to optimize the AHC design. The experimental results indicate that the novel AHC has an excellent performance for the oil–water separation.展开更多
A data processing method was proposed for eliminating the end restraint in triaxial tests of soil. A digital image processing method was used to calculate the local deformations and local stresses for any region on th...A data processing method was proposed for eliminating the end restraint in triaxial tests of soil. A digital image processing method was used to calculate the local deformations and local stresses for any region on the surface of triaxial soil specimens. The principle and implementation of this digital image processing method were introduced as well as the calculation method for local mechanical properties of soil specimens. Comparisons were made between the test results calculated by the data from both the entire specimen and local regions, and it was found that the deformations were more uniform in the middle region compared with the entire specimen. In order to quantify the nonuniform characteristic of deformation, the non-uniformity coefficients of strain were defined and calculated. Traditional and end-lubricated triaxial tests were conducted under the same condition to investigate the effects of using local region data for deformation calculation on eliminating the end restraint of specimens. After the statistical analysis of all test results, it was concluded that for the tested soil specimen with the size of 39.1 mm × 80 ram, the utilization of the middle 35 mm region of traditional specimens in data processing had a better effect on eliminating end restraint compared with end lubrication. Furthermore, the local data analysis in this paper was validated through the comparisons with the test results from other researchers.展开更多
This paper studies nonparametric estimation of the regression function with surrogate outcome data under double-sampling designs, where a proxy response is observed for the full sample and the true response is observe...This paper studies nonparametric estimation of the regression function with surrogate outcome data under double-sampling designs, where a proxy response is observed for the full sample and the true response is observed on a validation set. A new estimation approach is proposed for estimating the regression function. The authors first estimate the regression function with a kernel smoother based on the validation subsample, and then improve the estimation by utilizing the information on the incomplete observations from the non-validation subsample and the surrogate of response from the full sample. Asymptotic normality of the proposed estimator is derived. The effectiveness of the proposed method is demonstrated via simulations.展开更多
基金Supported by the Scientific Research Project of Beijing Municipal Commission of Education(KM201510017008)the National Natural Science Foundation of China(21677018)+1 种基金the State Key Laboratory of Heavy Oil Processing(SKLOP201403002)the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions(CIT&TCD20150317)
文摘A novel hydrocyclone with guide vanes, named as axial hydrocyclone(AHC), is designed to tackle the problem of oil–water separation faced by most mature oilfields. Optimal design of the AHC is carried out by using numerical methods. The effects of guide vanes, cone angle, tapered angle and overflow pipe on the oil–water separation are discussed in this paper. The results show that a double swirling flow is generated in the tapered section where oil–water separation occurs. Both the cylindrical and the tapered section have important influences on AHC performance. On the basis of single factor results, response surface methodology is employed to optimize the AHC design. The experimental results indicate that the novel AHC has an excellent performance for the oil–water separation.
基金Supported by Major State Basic Research Development Program of China("973" Program,No.2010CB731502)
文摘A data processing method was proposed for eliminating the end restraint in triaxial tests of soil. A digital image processing method was used to calculate the local deformations and local stresses for any region on the surface of triaxial soil specimens. The principle and implementation of this digital image processing method were introduced as well as the calculation method for local mechanical properties of soil specimens. Comparisons were made between the test results calculated by the data from both the entire specimen and local regions, and it was found that the deformations were more uniform in the middle region compared with the entire specimen. In order to quantify the nonuniform characteristic of deformation, the non-uniformity coefficients of strain were defined and calculated. Traditional and end-lubricated triaxial tests were conducted under the same condition to investigate the effects of using local region data for deformation calculation on eliminating the end restraint of specimens. After the statistical analysis of all test results, it was concluded that for the tested soil specimen with the size of 39.1 mm × 80 ram, the utilization of the middle 35 mm region of traditional specimens in data processing had a better effect on eliminating end restraint compared with end lubrication. Furthermore, the local data analysis in this paper was validated through the comparisons with the test results from other researchers.
基金This research is supported by the National Natural Science Foundation of the US under Grant No. DMS- 0906482.
文摘This paper studies nonparametric estimation of the regression function with surrogate outcome data under double-sampling designs, where a proxy response is observed for the full sample and the true response is observed on a validation set. A new estimation approach is proposed for estimating the regression function. The authors first estimate the regression function with a kernel smoother based on the validation subsample, and then improve the estimation by utilizing the information on the incomplete observations from the non-validation subsample and the surrogate of response from the full sample. Asymptotic normality of the proposed estimator is derived. The effectiveness of the proposed method is demonstrated via simulations.
