Objective To evaluate the value of renal parenchymal volume and thickness by non-contrast spiral CT in evaluating the differential glomerular filtration rate ( GFR) for chronic obstructed kidneys,and to compare the co...Objective To evaluate the value of renal parenchymal volume and thickness by non-contrast spiral CT in evaluating the differential glomerular filtration rate ( GFR) for chronic obstructed kidneys,and to compare the correlations between two morphologic indices of renal parenchyma and GFR for chronic obstructed kidneys.展开更多
This paper investigates the equivalent model for the friction boundary condition between blank and holder during sheet metal forming simulation, and proposes an equivalent algorithm, the thickness threshold value algo...This paper investigates the equivalent model for the friction boundary condition between blank and holder during sheet metal forming simulation, and proposes an equivalent algorithm, the thickness threshold value algorithm, for the first time based on thickness weighting. This algorithm assumes that the holder clearance is uniform during sheet metal forming; and the main reason for the unevenness of friction force distribution under the holder is that the uneven deformation of the blank leads to its uneven thickness distribution, which makes the local pressure on the blank distributed unevenly. The algorithm proposed in this paper can effectively simulate the influence of the unevenness on the forming process. Validity of this algorithm is verified by a comparison between the simulation results and the experimental ones for the drawing process of a car spring base.展开更多
文摘Objective To evaluate the value of renal parenchymal volume and thickness by non-contrast spiral CT in evaluating the differential glomerular filtration rate ( GFR) for chronic obstructed kidneys,and to compare the correlations between two morphologic indices of renal parenchyma and GFR for chronic obstructed kidneys.
基金Project supported by Project 985-Automotive Engineering of Jilin University.
文摘This paper investigates the equivalent model for the friction boundary condition between blank and holder during sheet metal forming simulation, and proposes an equivalent algorithm, the thickness threshold value algorithm, for the first time based on thickness weighting. This algorithm assumes that the holder clearance is uniform during sheet metal forming; and the main reason for the unevenness of friction force distribution under the holder is that the uneven deformation of the blank leads to its uneven thickness distribution, which makes the local pressure on the blank distributed unevenly. The algorithm proposed in this paper can effectively simulate the influence of the unevenness on the forming process. Validity of this algorithm is verified by a comparison between the simulation results and the experimental ones for the drawing process of a car spring base.