目的心脏手术患者液体治疗策略历来存有争论。文中旨在观察目标导向血流动力学管理策略对非体外循环冠状动脉搭桥手术患者预后的影响。方法选取安徽医科大学第一附属医院2016年1-12月择期行非体外循环冠状动脉搭桥术的98例患者纳入研究...目的心脏手术患者液体治疗策略历来存有争论。文中旨在观察目标导向血流动力学管理策略对非体外循环冠状动脉搭桥手术患者预后的影响。方法选取安徽医科大学第一附属医院2016年1-12月择期行非体外循环冠状动脉搭桥术的98例患者纳入研究。以2016年6月20日进行质量改进为截点。质量改进前56例患者纳入对照组、质量改进后42例患者纳入试验组。质量改进措施为采用以每博量变异和心脏指数为目标导向液体治疗输注液体,标准化使用血管活性药物,优化血流动力学。通过电子病历系统采集术中和术后数据,比较两组患者的液体出入量、术后住院天数和并发症、术后苏醒时间、24小时胸腔引流量、6小时内拔管率、ICU驻留时间、术后第1天肌钙蛋白I水平、30天病死率以及半年病死率。结果采用目标导向血流动力学管理后,试验组较对照组液体总入量差异无统计学意义,其中万汶输注量显著增加[(676.79±380.90)mL vs(890.48±222.58)mL]、晶体输注量显著减少[(663.84±224.97)mL vs(430.24±201.76)mL]、尿量显著增加[(516.07±224.87)mL vs(695.24±311.53)mL],液体正平衡显著减少[(683.82±556.08)mL vs(456.43±505.36)mL],差异均有统计学意义(P<0.05);自体血回输、红细胞输注比例、出血量两组间差异无统计学意义(P>0.05)。两组术后苏醒时间、24小时胸腔引流量、6小时内拔管率、术后第1天肌钙蛋白I水平、ICU驻留时间无统计学差异(P>0.05)。两组术后住院天数试验组较对照组显著减少(11.81 d vs 13.82 d,P<0.05)。对其对数转换后进行多元线性回归分析,得出质量改进措施的标准化系数B为-0.296(SE=0.061,P<0.05),说明其他条件相同时,采用目标导向血流动力学管理能减少术后住院天数19.4%(95%CI 7.3%～31.5%)。术后并发症从41.07%下降至16.67%,差异有统计学意义(P<0.05)。结论非体外循环冠状动脉搭桥术中采用目标导向血流动力学管理策略可有效降低术后并发症、减少术后住院天数,改善患者短期预后。展开更多
The deformation and failure of coal and rock is energy-driving results according to thermodynamics.It is important to study the strain energy characteristics of coal-rock composite samples to better understand the def...The deformation and failure of coal and rock is energy-driving results according to thermodynamics.It is important to study the strain energy characteristics of coal-rock composite samples to better understand the deformation and failure mechanism of of coal-rock composite structures.In this research,laboratory tests and numerical simulation of uniaxial compressions of coal-rock composite samples were carried out with five different loading rates.The test results show that strength,deformation,acoustic emission(AE)and energy evolution of coal-rock composite sample all have obvious loading rate effects.The uniaxial compressive strength and elastic modulus increase with the increase of loading rate.And with the increase of loading rate,the AE energy at the peak strength of coal-rock composites increases first,then decreases,and then increases.With the increase of loading rate,the AE cumulative count first decreases and then increases.And the total absorption energy and dissipation energy of coal-rock composite samples show non-linear increasing trends,while release elastic strain energy increases first and then decreases.The laboratory experiments conducted on coal-rock composite samples were simulated numerically using the particle flow code(PFC).With careful selection of suitable material constitutive models for coal and rock,and accurate estimation and calibration of mechanical parameters of coal-rock composite sample,it was possible to obtain a good agreement between the laboratory experimental and numerical results.This research can provide references for understanding failure of underground coalrock composite structure by using energy related measuring methods.展开更多
The stability control of surrounding rock for large or super-large section chamber is a difficult technical problem in deep mining condition.Based on the in-site geological conditions of Longgu coal mine,this paper us...The stability control of surrounding rock for large or super-large section chamber is a difficult technical problem in deep mining condition.Based on the in-site geological conditions of Longgu coal mine,this paper used the dynamic module of FLAC3D to study the response characteristics of deep super-large section chamber under dynamic and static combined loading condition.Results showed that under the static loading condition,the maximum vertical stress,deformation and failure range are large,where the stress concentration coefficient is 1.64.The maximum roof-to-floor and two-sides deformations are 54.6 mm and 53.1 mm,respectively.Then,under the dynamic and static combined loading condition:(1)The influence of dynamic load frequency on the two-sides is more obvious;(2)The dynamic load amplitude has the greatest influence on the stress concentration degree,and the plastic failure tends to develop to the deeper;(3)With the dynamic load source distance increase,the response of surrounding rock is gradually attenuated.On this basis,empirical equations for each dynamic load conditions were obtained by using regression analysis method,and all correlation coefficients are greater than 0.99.This research provided reference for the supporting design of deep super-large section chamber under same or similar conditions.展开更多
文摘目的心脏手术患者液体治疗策略历来存有争论。文中旨在观察目标导向血流动力学管理策略对非体外循环冠状动脉搭桥手术患者预后的影响。方法选取安徽医科大学第一附属医院2016年1-12月择期行非体外循环冠状动脉搭桥术的98例患者纳入研究。以2016年6月20日进行质量改进为截点。质量改进前56例患者纳入对照组、质量改进后42例患者纳入试验组。质量改进措施为采用以每博量变异和心脏指数为目标导向液体治疗输注液体,标准化使用血管活性药物,优化血流动力学。通过电子病历系统采集术中和术后数据,比较两组患者的液体出入量、术后住院天数和并发症、术后苏醒时间、24小时胸腔引流量、6小时内拔管率、ICU驻留时间、术后第1天肌钙蛋白I水平、30天病死率以及半年病死率。结果采用目标导向血流动力学管理后,试验组较对照组液体总入量差异无统计学意义,其中万汶输注量显著增加[(676.79±380.90)mL vs(890.48±222.58)mL]、晶体输注量显著减少[(663.84±224.97)mL vs(430.24±201.76)mL]、尿量显著增加[(516.07±224.87)mL vs(695.24±311.53)mL],液体正平衡显著减少[(683.82±556.08)mL vs(456.43±505.36)mL],差异均有统计学意义(P<0.05);自体血回输、红细胞输注比例、出血量两组间差异无统计学意义(P>0.05)。两组术后苏醒时间、24小时胸腔引流量、6小时内拔管率、术后第1天肌钙蛋白I水平、ICU驻留时间无统计学差异(P>0.05)。两组术后住院天数试验组较对照组显著减少(11.81 d vs 13.82 d,P<0.05)。对其对数转换后进行多元线性回归分析,得出质量改进措施的标准化系数B为-0.296(SE=0.061,P<0.05),说明其他条件相同时,采用目标导向血流动力学管理能减少术后住院天数19.4%(95%CI 7.3%～31.5%)。术后并发症从41.07%下降至16.67%,差异有统计学意义(P<0.05)。结论非体外循环冠状动脉搭桥术中采用目标导向血流动力学管理策略可有效降低术后并发症、减少术后住院天数,改善患者短期预后。
文摘报道了一种实现高能量输出的激光二极管(LD)泵浦无水冷全固态Nd∶YAG双程放大器结构。整个放大系统采用了泵浦与晶体棒集成的模块以及半导体制冷器(TEC),从而实现了激光系统的小型化。总腔长为730 mm。在10 Hz重复频率下,主振荡器得到了最大脉冲能量为350 m J的激光输出。脉宽为9.7 ns,光束质量M^2在两个方向分别为7.7和12.3。并进行了双程放大的研究,双程放大后得到了740 m J、10 ns的激光输出。
基金Projects(51774196,51804181,51874190)supported by the National Natural Science Foundation of ChinaProject(2019GSF111020)supported by the Key R&D Program of Shandong Province,ChinaProject(201908370205)supported by the China Scholarship Council。
文摘The deformation and failure of coal and rock is energy-driving results according to thermodynamics.It is important to study the strain energy characteristics of coal-rock composite samples to better understand the deformation and failure mechanism of of coal-rock composite structures.In this research,laboratory tests and numerical simulation of uniaxial compressions of coal-rock composite samples were carried out with five different loading rates.The test results show that strength,deformation,acoustic emission(AE)and energy evolution of coal-rock composite sample all have obvious loading rate effects.The uniaxial compressive strength and elastic modulus increase with the increase of loading rate.And with the increase of loading rate,the AE energy at the peak strength of coal-rock composites increases first,then decreases,and then increases.With the increase of loading rate,the AE cumulative count first decreases and then increases.And the total absorption energy and dissipation energy of coal-rock composite samples show non-linear increasing trends,while release elastic strain energy increases first and then decreases.The laboratory experiments conducted on coal-rock composite samples were simulated numerically using the particle flow code(PFC).With careful selection of suitable material constitutive models for coal and rock,and accurate estimation and calibration of mechanical parameters of coal-rock composite sample,it was possible to obtain a good agreement between the laboratory experimental and numerical results.This research can provide references for understanding failure of underground coalrock composite structure by using energy related measuring methods.
基金Project(2018YFC0604703)supported by the National Key R&D Program of ChinaProjects(51804181,51874190)supported by the National Natural Science Foundation of China+3 种基金Project(ZR2018QEE002)supported by the Shandong Province Natural Science Fund,ChinaProject(ZR2018ZA0603)supported by the Major Program of Shandong Province Natural Science Foundation,ChinaProject(2019GSF116003)supported by the Key R&D Project of Shandong Province,ChinaProject(SDKDYC190234)supported by the Shandong University of Science and Technology,Graduate Student Technology Innovation Project,China。
文摘The stability control of surrounding rock for large or super-large section chamber is a difficult technical problem in deep mining condition.Based on the in-site geological conditions of Longgu coal mine,this paper used the dynamic module of FLAC3D to study the response characteristics of deep super-large section chamber under dynamic and static combined loading condition.Results showed that under the static loading condition,the maximum vertical stress,deformation and failure range are large,where the stress concentration coefficient is 1.64.The maximum roof-to-floor and two-sides deformations are 54.6 mm and 53.1 mm,respectively.Then,under the dynamic and static combined loading condition:(1)The influence of dynamic load frequency on the two-sides is more obvious;(2)The dynamic load amplitude has the greatest influence on the stress concentration degree,and the plastic failure tends to develop to the deeper;(3)With the dynamic load source distance increase,the response of surrounding rock is gradually attenuated.On this basis,empirical equations for each dynamic load conditions were obtained by using regression analysis method,and all correlation coefficients are greater than 0.99.This research provided reference for the supporting design of deep super-large section chamber under same or similar conditions.
