In this paper, the 1-D Burgers equation is studied, the existence of its mixed generalized solution and semi-discrete and fully discrete mixed finite element solu-tions are discussed, and their error estimates are ana...In this paper, the 1-D Burgers equation is studied, the existence of its mixed generalized solution and semi-discrete and fully discrete mixed finite element solu-tions are discussed, and their error estimates are analyzed. And finally, an example of numerical simulation of fully discrete mixed finite element solution is also given.展开更多
目的评估基于快速康复外科理念系统治疗骨质疏松性椎体压缩骨折的临床疗效。方法回顾2015年1月至2017年6月我科基于快速康复外科(ERAS)理念因骨质疏松性椎体压缩骨折(OVCFs)行椎体后凸成形术(PKP),且随访期间系统规律治疗原发病骨质疏...目的评估基于快速康复外科理念系统治疗骨质疏松性椎体压缩骨折的临床疗效。方法回顾2015年1月至2017年6月我科基于快速康复外科(ERAS)理念因骨质疏松性椎体压缩骨折(OVCFs)行椎体后凸成形术(PKP),且随访期间系统规律治疗原发病骨质疏松患者125例。收集术前及术后1周疼痛模拟VAS(visual analog scale)评分和伤残ODI(oswestry disability index)指数,记录术前及术后12个月骨密度(bone mass density,BMD)指标及血清I型胶原氨基端前肽(procollagen type1 amino-terminal propeptide, P1NP)、β胶原降解产物(beta collagen degradation products,β-CTX)及25-羟基维生素D(25(OH)D)等骨代谢指标进行比较分析。结果系统治疗1周后,VAS评分由入院时(6.35±1.0)分降至(1.34±0.9)分( P <0.001),ODI由入院时(44.8±5.3)%降至(16.8±3.5)%( P <0.001)。术后12个月,BMD指标 T 值由术前(-2.7±0.3)SD增至(-2.5±0.2)SD( P <0.001),骨代谢指标PINP由术前(57.0±17.7)ng/mL增至(73.3±19.7)ng/mL( P <0.001),β-CTX由术前(502.3±221.9)pg/mL降至(220.0±123.6)pg/mL( P <0.001),25(OH)D由术前(35.3±2.2)nmol/L增至(36.2±7.7)nmol/L( P =0.202)。结论①PKP手术可有效缓解OVCFs患者腰背痛,改善患者双下肢功能状态,提高其生活质量;②基于ERAS理念系统治疗OVCFs,可通过抑制骨吸收、促进新骨形成来提高骨密度、改善骨质,对预防骨质疏松再骨折具有重要意义。展开更多
In this paper we have studied the mixed finite element method for the non stationary conduct ic n-convection problems, where the coupled equations governing viscous incompressible flow and heat transfer process, and i...In this paper we have studied the mixed finite element method for the non stationary conduct ic n-convection problems, where the coupled equations governing viscous incompressible flow and heat transfer process, and incompressible fluid are the Boussinesq approximations to the nonstationary Navier-Stokes equations.We have discussed the existence of continuous, semi-discrete and fully discrete solutions, and derive the error estimates for the approximate solutions on the continuous and discrete time cases.展开更多
In this paper, a nonlinear Galerkin (semi-discrete) mixed element method for the non stationary conduction-convection problems is presented. The scheme is based on two finite element spaces XH and Xh for the approxima...In this paper, a nonlinear Galerkin (semi-discrete) mixed element method for the non stationary conduction-convection problems is presented. The scheme is based on two finite element spaces XH and Xh for the approximation of the velocity,defined respectively on a coarse grid with grid size H and another fine grid with grid size h << H, a finite element space Mh for the approximation of the pressuxe and two finite element spaces WH and Wh for the approximation of the temperature,also defined respectively on the coarse grid with grid size H and another fine grid with grid size h << H. Both of the non linearity and time dependence are treated only in the coarse space. We have proved that the error between the nonlinear Galerkin mixed element solution and standard Galerkin mixed element solutionis of the order of Hm+1(m>1), all in velocity (H1(Ω)2 norm), pressure (L2(Ω)norm) and temperature (H1 (Ω) norm).展开更多
文摘In this paper, the 1-D Burgers equation is studied, the existence of its mixed generalized solution and semi-discrete and fully discrete mixed finite element solu-tions are discussed, and their error estimates are analyzed. And finally, an example of numerical simulation of fully discrete mixed finite element solution is also given.
文摘目的评估基于快速康复外科理念系统治疗骨质疏松性椎体压缩骨折的临床疗效。方法回顾2015年1月至2017年6月我科基于快速康复外科(ERAS)理念因骨质疏松性椎体压缩骨折(OVCFs)行椎体后凸成形术(PKP),且随访期间系统规律治疗原发病骨质疏松患者125例。收集术前及术后1周疼痛模拟VAS(visual analog scale)评分和伤残ODI(oswestry disability index)指数,记录术前及术后12个月骨密度(bone mass density,BMD)指标及血清I型胶原氨基端前肽(procollagen type1 amino-terminal propeptide, P1NP)、β胶原降解产物(beta collagen degradation products,β-CTX)及25-羟基维生素D(25(OH)D)等骨代谢指标进行比较分析。结果系统治疗1周后,VAS评分由入院时(6.35±1.0)分降至(1.34±0.9)分( P <0.001),ODI由入院时(44.8±5.3)%降至(16.8±3.5)%( P <0.001)。术后12个月,BMD指标 T 值由术前(-2.7±0.3)SD增至(-2.5±0.2)SD( P <0.001),骨代谢指标PINP由术前(57.0±17.7)ng/mL增至(73.3±19.7)ng/mL( P <0.001),β-CTX由术前(502.3±221.9)pg/mL降至(220.0±123.6)pg/mL( P <0.001),25(OH)D由术前(35.3±2.2)nmol/L增至(36.2±7.7)nmol/L( P =0.202)。结论①PKP手术可有效缓解OVCFs患者腰背痛,改善患者双下肢功能状态,提高其生活质量;②基于ERAS理念系统治疗OVCFs,可通过抑制骨吸收、促进新骨形成来提高骨密度、改善骨质,对预防骨质疏松再骨折具有重要意义。
文摘In this paper we have studied the mixed finite element method for the non stationary conduct ic n-convection problems, where the coupled equations governing viscous incompressible flow and heat transfer process, and incompressible fluid are the Boussinesq approximations to the nonstationary Navier-Stokes equations.We have discussed the existence of continuous, semi-discrete and fully discrete solutions, and derive the error estimates for the approximate solutions on the continuous and discrete time cases.
文摘In this paper, a nonlinear Galerkin (semi-discrete) mixed element method for the non stationary conduction-convection problems is presented. The scheme is based on two finite element spaces XH and Xh for the approximation of the velocity,defined respectively on a coarse grid with grid size H and another fine grid with grid size h << H, a finite element space Mh for the approximation of the pressuxe and two finite element spaces WH and Wh for the approximation of the temperature,also defined respectively on the coarse grid with grid size H and another fine grid with grid size h << H. Both of the non linearity and time dependence are treated only in the coarse space. We have proved that the error between the nonlinear Galerkin mixed element solution and standard Galerkin mixed element solutionis of the order of Hm+1(m>1), all in velocity (H1(Ω)2 norm), pressure (L2(Ω)norm) and temperature (H1 (Ω) norm).
