Landslides in Tianshui Basin, Gansu Province, Northwest China, severely affect the local population and the economy;therefore,understanding their evolution and kinematics is of great interest for landslide risk assess...Landslides in Tianshui Basin, Gansu Province, Northwest China, severely affect the local population and the economy;therefore,understanding their evolution and kinematics is of great interest for landslide risk assessment and prevention. However, there is no unified classification standard for the types of loess landslides in Tianshui.In this study, we explored the landslide distribution and failure characteristics by means of field investigation,remotesensinginterpretation,geological mapping, drilling exploration and shearwave velocity tests, and established a database of Tianshui landslides. Our analysis shows that shear zones in mudstone usually develop in weak intercalated layers. Landslides occur mainly along the West Qinling faults on slopes with gradients of 10° to 25° and on southeast-and southwest-facing slopes.These landslides were classified into five types: loess landslides, loess–mudstone interface landslides, loess flow-slides, loess–mudstone plane landslides and loess–mudstone cutting landslides. We discussed the evolution and failure process of each landslide type and analyzed the formation mechanism and motion characteristics of large-scale landslides. The analysis results show that the landslides in the study area are characterized by a gentle slope, long runout and high risk. The relationship between the runout L and the vertical drop H of the large-scale landslides in the study area is L > 4 H. There are good correlations between the equivalent friction coefficient of largescale landslides and their maximum height, runout,area and volume. The sliding zone of large-scale landslides often develops in the bedrock contact zone or in a weak interlayer within mudstone. From microstructure analysis, undisturbed mudstone consists mainly of small aggregates with dispersed inter-aggregate pores, whereas sheared clay has a more homogeneous structure. Linear striations are well developed on shear surfaces, and the clay pores in those surfaces have a more uniform distribution than those in undisturbed clay.展开更多
Background: Hyperglycemia in hospitalized patients is associated with poor clinical outcomes. Scheduled Subcutaneous Insulin therapy has been recommended for better glycemic control. Aims: To compare efficacy and safe...Background: Hyperglycemia in hospitalized patients is associated with poor clinical outcomes. Scheduled Subcutaneous Insulin therapy has been recommended for better glycemic control. Aims: To compare efficacy and safety of traditional sliding scale insulin (SSI) versus modified 70/30 insulin versus basal plus supplemental scale (SS) insulin regimens for glycemic control of inpatients with diabetes. Methods: In a prospective trial, 62 patients with diabetes were randomized to receive either hospital SSI (N = 22), or twice daily 70/30 insulin plus supplemental lunchtime insulin for BG ≥ 150 mg/dL (N = 21) or once every night glargine plus prandial glulisine for BG ≥ 150 mg/dL (N = 19). 70/30 insulin and glargine were started respectively at 0.4 and 0.2 U/kg/day for BG ≤ 200 mg/dL or 0.5 and 0.3 U/kg/day for BG above 200 mg/dL. Results: Starting at BG level of 204 ± 68, 200 ± 50 and 241 ± 94 mg/dL in SSI, 70/30 insulin and glargine/glulisine groups respectively, (F(2,35.47) = 1.467, p = 0.244, Welch test), mean daily BG after first day of hospitalization was statistically significant (F(2,35.58) = 7.043, p = 0.003, Welch test) lower in 70/30 insulin group (171 ± 38 mg/dL) compared to (218 ± 71 mg/dL) in SSI group (p = 0.026) and (225 ± 65 mg/dL) in glargine/glulisine group (p = 0.01). Conclusions: With poorly educated nursing staff, basal plus SS insulin failed to provide adequate glycemic control. However, tailored 70/30 insulin regimen resulted in statistically significant glycemic control compared to traditional SSI.展开更多
An integral terminal sliding mode controller is proposed in order to control chaos in a rod-type plasma torch system.In this method, a new sliding surface is defined based on a combination of the conventional sliding ...An integral terminal sliding mode controller is proposed in order to control chaos in a rod-type plasma torch system.In this method, a new sliding surface is defined based on a combination of the conventional sliding surface in terminal sliding mode control and a nonlinear function of the integral of the system states. It is assumed that the dynamics of a chaotic system are unknown and also the system is exposed to disturbance and unstructured uncertainty. To achieve a chattering-free and high-speed response for such an unknown system, an adaptive neuro-fuzzy inference system is utilized in the next step to approximate the unknown part of the nonlinear dynamics. Then, the proposed integral terminal sliding mode controller stabilizes the approximated system based on Lyapunov＇s stability theory. In addition, a Bee algorithm is used to select the coefficients of integral terminal sliding mode controller to improve the performance of the proposed method. Simulation results demonstrate the improvement in the response speed, chattering rejection, transient response,and robustness against uncertainties.展开更多
基金This study was sponsored by National Natural Science Foundation of China(Grant No.41902269 and No.41702343)Project of China geological survey(Grant No.DD20190717)The authors express their sincere thanks to the reviewers and editor for their help.
文摘Landslides in Tianshui Basin, Gansu Province, Northwest China, severely affect the local population and the economy;therefore,understanding their evolution and kinematics is of great interest for landslide risk assessment and prevention. However, there is no unified classification standard for the types of loess landslides in Tianshui.In this study, we explored the landslide distribution and failure characteristics by means of field investigation,remotesensinginterpretation,geological mapping, drilling exploration and shearwave velocity tests, and established a database of Tianshui landslides. Our analysis shows that shear zones in mudstone usually develop in weak intercalated layers. Landslides occur mainly along the West Qinling faults on slopes with gradients of 10° to 25° and on southeast-and southwest-facing slopes.These landslides were classified into five types: loess landslides, loess–mudstone interface landslides, loess flow-slides, loess–mudstone plane landslides and loess–mudstone cutting landslides. We discussed the evolution and failure process of each landslide type and analyzed the formation mechanism and motion characteristics of large-scale landslides. The analysis results show that the landslides in the study area are characterized by a gentle slope, long runout and high risk. The relationship between the runout L and the vertical drop H of the large-scale landslides in the study area is L > 4 H. There are good correlations between the equivalent friction coefficient of largescale landslides and their maximum height, runout,area and volume. The sliding zone of large-scale landslides often develops in the bedrock contact zone or in a weak interlayer within mudstone. From microstructure analysis, undisturbed mudstone consists mainly of small aggregates with dispersed inter-aggregate pores, whereas sheared clay has a more homogeneous structure. Linear striations are well developed on shear surfaces, and the clay pores in those surfaces have a more uniform distribution than those in undisturbed clay.
文摘Background: Hyperglycemia in hospitalized patients is associated with poor clinical outcomes. Scheduled Subcutaneous Insulin therapy has been recommended for better glycemic control. Aims: To compare efficacy and safety of traditional sliding scale insulin (SSI) versus modified 70/30 insulin versus basal plus supplemental scale (SS) insulin regimens for glycemic control of inpatients with diabetes. Methods: In a prospective trial, 62 patients with diabetes were randomized to receive either hospital SSI (N = 22), or twice daily 70/30 insulin plus supplemental lunchtime insulin for BG ≥ 150 mg/dL (N = 21) or once every night glargine plus prandial glulisine for BG ≥ 150 mg/dL (N = 19). 70/30 insulin and glargine were started respectively at 0.4 and 0.2 U/kg/day for BG ≤ 200 mg/dL or 0.5 and 0.3 U/kg/day for BG above 200 mg/dL. Results: Starting at BG level of 204 ± 68, 200 ± 50 and 241 ± 94 mg/dL in SSI, 70/30 insulin and glargine/glulisine groups respectively, (F(2,35.47) = 1.467, p = 0.244, Welch test), mean daily BG after first day of hospitalization was statistically significant (F(2,35.58) = 7.043, p = 0.003, Welch test) lower in 70/30 insulin group (171 ± 38 mg/dL) compared to (218 ± 71 mg/dL) in SSI group (p = 0.026) and (225 ± 65 mg/dL) in glargine/glulisine group (p = 0.01). Conclusions: With poorly educated nursing staff, basal plus SS insulin failed to provide adequate glycemic control. However, tailored 70/30 insulin regimen resulted in statistically significant glycemic control compared to traditional SSI.
文摘An integral terminal sliding mode controller is proposed in order to control chaos in a rod-type plasma torch system.In this method, a new sliding surface is defined based on a combination of the conventional sliding surface in terminal sliding mode control and a nonlinear function of the integral of the system states. It is assumed that the dynamics of a chaotic system are unknown and also the system is exposed to disturbance and unstructured uncertainty. To achieve a chattering-free and high-speed response for such an unknown system, an adaptive neuro-fuzzy inference system is utilized in the next step to approximate the unknown part of the nonlinear dynamics. Then, the proposed integral terminal sliding mode controller stabilizes the approximated system based on Lyapunov＇s stability theory. In addition, a Bee algorithm is used to select the coefficients of integral terminal sliding mode controller to improve the performance of the proposed method. Simulation results demonstrate the improvement in the response speed, chattering rejection, transient response,and robustness against uncertainties.
