Measuring the internal stress of Al alloy forgings accurately is critical for controlling the deformation during the subsequent machine process.In this work,the crack compliance method was used to calculate the intern...Measuring the internal stress of Al alloy forgings accurately is critical for controlling the deformation during the subsequent machine process.In this work,the crack compliance method was used to calculate the internal residual stress of Al-Cu high strength alloys,and the effect of various model parameters of crack compliance method on the calculated precision was studied by combining the numerical simulation and experimental method.The results show that the precision first increased and then decreased with increasing the crack range.The decreased precision when using a high crack range was due to the strain fluctuation during the machining process,and the optimized crack range was 71%of the thickness of forgings.Low orders of Legendre polynomial can result in residual stress curve more smooth,while high orders led to the occurrence of distortion.The Tikhonov regularization method effectively suppressed the distortion of residual stress caused by the fluctuation of strain data,which significantly improved the precision.In addition,The crack compliance method with optimized parameters was used to measure the residual stress of Al-Cu alloy with different quenching methods.The calculated results demonstrated that the distribution of residual stress was obtained accurately.展开更多
The overuse of clinical laboratory services has been documented for many years. This overuse use does not contribute to the quality of medical care, does not shorten hospital stay, nor reduce mortality. The utilizatio...The overuse of clinical laboratory services has been documented for many years. This overuse use does not contribute to the quality of medical care, does not shorten hospital stay, nor reduce mortality. The utilization of diagnostic laboratories has increased over the last decade around the world. This increased laboratory use is appropriate if it allows accurate diagnoses to be made, ideal treatment to be identified and monitored, accurate prognoses to be established, and patients’ hospital stays to be shortened. Thus, improving the appropriateness of testing behavior and reducing the number of laboratory tests have been recognized as essential parts of quality improvement program. In this study, the effectiveness of a computer-based system in improving the laboratory test-ordering in a general hospital was investigated. The study was conducted through four stages, the preparation stage, the pre-intervention stage, the post-intervention 1) stage and post-intervention 2) stage. Guideline and computer system were developed during preparation stage. Medical records were reviewed against guideline recommendations before any intervention during the pre-intervention stage, after guideline dissemination through educational workshops during the post intervention 1) stage, and after implementation of the computer system with the new requesting form during the post intervention 2) stage. The study revealed that the computer-based system achieved a statistically significant increase in the percentage of appropriate use from 44.6% in the post-intervention 1) stage to 55.6%, and a statistically significant increase in the compliance with guideline by prescriber as well as increased in guideline conformity rate from 16.7% in the post-intervention 1) stage to 32.5% in the post-intervention 2) stage, and decreased in the percentage of prescribers whose level was unsatisfactory from 85.4% the post-intervention 1) stage to 66.7% in the post-intervention 2) stage.展开更多
基金Project(51875583)supported by the National Natural Science Foundation of ChinaProject(zzyjkt2018-03)supported by the State Key Laboratory of High Performance Complex Manufacturing,China。
文摘Measuring the internal stress of Al alloy forgings accurately is critical for controlling the deformation during the subsequent machine process.In this work,the crack compliance method was used to calculate the internal residual stress of Al-Cu high strength alloys,and the effect of various model parameters of crack compliance method on the calculated precision was studied by combining the numerical simulation and experimental method.The results show that the precision first increased and then decreased with increasing the crack range.The decreased precision when using a high crack range was due to the strain fluctuation during the machining process,and the optimized crack range was 71%of the thickness of forgings.Low orders of Legendre polynomial can result in residual stress curve more smooth,while high orders led to the occurrence of distortion.The Tikhonov regularization method effectively suppressed the distortion of residual stress caused by the fluctuation of strain data,which significantly improved the precision.In addition,The crack compliance method with optimized parameters was used to measure the residual stress of Al-Cu alloy with different quenching methods.The calculated results demonstrated that the distribution of residual stress was obtained accurately.
文摘The overuse of clinical laboratory services has been documented for many years. This overuse use does not contribute to the quality of medical care, does not shorten hospital stay, nor reduce mortality. The utilization of diagnostic laboratories has increased over the last decade around the world. This increased laboratory use is appropriate if it allows accurate diagnoses to be made, ideal treatment to be identified and monitored, accurate prognoses to be established, and patients’ hospital stays to be shortened. Thus, improving the appropriateness of testing behavior and reducing the number of laboratory tests have been recognized as essential parts of quality improvement program. In this study, the effectiveness of a computer-based system in improving the laboratory test-ordering in a general hospital was investigated. The study was conducted through four stages, the preparation stage, the pre-intervention stage, the post-intervention 1) stage and post-intervention 2) stage. Guideline and computer system were developed during preparation stage. Medical records were reviewed against guideline recommendations before any intervention during the pre-intervention stage, after guideline dissemination through educational workshops during the post intervention 1) stage, and after implementation of the computer system with the new requesting form during the post intervention 2) stage. The study revealed that the computer-based system achieved a statistically significant increase in the percentage of appropriate use from 44.6% in the post-intervention 1) stage to 55.6%, and a statistically significant increase in the compliance with guideline by prescriber as well as increased in guideline conformity rate from 16.7% in the post-intervention 1) stage to 32.5% in the post-intervention 2) stage, and decreased in the percentage of prescribers whose level was unsatisfactory from 85.4% the post-intervention 1) stage to 66.7% in the post-intervention 2) stage.
