为了研究大连多岩溶区的复杂地质条件对基坑开挖的影响,运用有限差分软件FLAC^(3D)对不同溶洞位置的基坑进行模拟,得到位移变化规律。同时利用单元安全状态评价指标ZSI(Zone State Index)对不同溶洞位置下基坑周围土体进行评价,针对影...为了研究大连多岩溶区的复杂地质条件对基坑开挖的影响,运用有限差分软件FLAC^(3D)对不同溶洞位置的基坑进行模拟,得到位移变化规律。同时利用单元安全状态评价指标ZSI(Zone State Index)对不同溶洞位置下基坑周围土体进行评价,针对影响较大区域溶洞提出合理的溶洞处理方案。研究结果表明:溶洞对基坑稳定性影响程度由大到小依次是被动区、过渡区、主动区。针对被动区溶洞采取开挖前注浆处理,通过对大连地区深基坑进行数值模拟确定的不同溶洞位置对基坑影响程度具有一定的指导意义,可为岩溶地区深基坑工程的设计与施工提供参考。展开更多
Objective:To evaluate surgical outcomes after implantation of the Zephyr ZSI 475 inflatable penile prosthesis(IPP)and patients’quality of life.Methods:From December 2014 to September 2018,15 patients underwent prosth...Objective:To evaluate surgical outcomes after implantation of the Zephyr ZSI 475 inflatable penile prosthesis(IPP)and patients’quality of life.Methods:From December 2014 to September 2018,15 patients underwent prosthesis implantation with ZSI 475.A retrospective review of clinical data was performed.Patients’quality of life after implantation was investigated with Quality of Life and Sexuality with Penile Prosthesis(QoLSPP)questionnaire.Results:The median age of patients was 57 years and the average follow-up time was 22 months.Twelve patients received a standard implantation due to severe erectile dysfunction(ED);three patients also presented penile curvature and additional corporoplasty with grafting was necessary.Three procedures had to be interrupted due to defects of the insertion tools.In one case a manufacturing defect resulted in a pump leak.In one case,a severe postoperative complication occurred,which requested explanation of the device.During the follow-up,four patients experienced mechanical failure of the prosthesis.Results of QoLSPP questionnaire at 12 months were skewed toward the positive end of the scale in all domains.Conclusion:In our initial experience,ZSI 475 suffered a high rate of mechanical failures;on the other hand,the company showed great commitment in order to improve the quality and reliability of the device.The lower cost of ZSI 475 may add to the chances of the product to become a cost-effective alternative to treat those patient who need a IPP.展开更多
针对临近暗渠的富水区基坑开挖施工复杂性,将单元状态指标ZSI(Zone State Index)和流-固耦合相结合,并采用有限差分法进行三维数值模拟分析。首先使用FLAC3D三维快速拉格朗日差分程序,建立了青岛地铁基坑的实际工程模型,依次计算求解了...针对临近暗渠的富水区基坑开挖施工复杂性,将单元状态指标ZSI(Zone State Index)和流-固耦合相结合,并采用有限差分法进行三维数值模拟分析。首先使用FLAC3D三维快速拉格朗日差分程序,建立了青岛地铁基坑的实际工程模型,依次计算求解了暗渠附近土体的垂直位移、水平位移和塑性区,进而采用ZSI方法对基坑开挖时暗渠附近土体的破坏状态以及渗透性系数进行了分析。模拟结果表明,暗渠的变形随着基坑的开挖深度的增加而增大,且靠近基坑的位置暗渠沉降位移最大值为4.15 mm,有渗流位移比无渗流位移大;基坑周围土体塑性区随开挖深度增加而增大,呈中部集中趋势;模拟计算位移值与实际监测数据变化趋势吻合,证明了模拟的正确性,且地下水的作用不可忽略。ZSI分析结果表明,随着基坑逐步开挖,暗渠附近土体的破坏范围逐渐增大,且在第三步开挖施工后,破坏区显著增大且呈中部集中趋势,渗透性系数在破坏区也相应增大。ZSI分析法将土体的破坏状态数量化,能精确直观地反映深挖基坑附近暗渠土体的破坏状态。ZSI与实测结果较为吻合,说明了单元状态指标可以对富水区邻近暗渠基坑开挖进行安全性评价与分析,为基坑施工的顺利进行提供保障。展开更多
The 3Φinduction motor is a broadly used electric machine in industrial applications,which plays a vital role in industries because of having plenty of beneficial impacts like low cost and easiness but the problems lik...The 3Φinduction motor is a broadly used electric machine in industrial applications,which plays a vital role in industries because of having plenty of beneficial impacts like low cost and easiness but the problems like decrease in motor speed due to load,high consumption of current and high ripple occurrence of ripples have reduced its preferences.The ultimate objective of this study is to control change in motor speed due to load variations.An improved Trans Z Source Inverter(ΓZSI)with a clamping diode is employed to maintain constant input voltage,reduce ripples and voltage overshoot.To operate induction motor at rated speed,different controllers are used.The conventional Proportional-Inte-gral(PI)controller suffers from high settling time and maximum peak overshoot.To overcome these limitations,Fractional Order Proportional Integral Derivative(FOPID)controller optimized by Gray Wolf Optimization(GWO)technique is employed to provide better performance by eliminating maximum peak overshoot pro-blems.The proposed speed controller provides good dynamic response and controls the induction motor more effectively.The complete setup is implemented in MATLAB Simulation to verify the simulation results.The proposed approach provides optimal performance with high torque and speed along with less steady state error.展开更多
以大东山隧道的石英岩为研究对象,进行循环加卸载条件下岩石蠕变–渗流耦合试验,分析了岩石加卸载过程中的蠕变、渗透性变化规律和渗流–蠕变耦合机理,得到压密阶段、裂纹扩展阶段和裂纹贯通阶段岩石体积应变的发展规律,总结了渗透率与...以大东山隧道的石英岩为研究对象,进行循环加卸载条件下岩石蠕变–渗流耦合试验,分析了岩石加卸载过程中的蠕变、渗透性变化规律和渗流–蠕变耦合机理,得到压密阶段、裂纹扩展阶段和裂纹贯通阶段岩石体积应变的发展规律,总结了渗透率与体积应变之间的关系。试验表明:轴向荷载0~50 MPa为压密阶段,继续加载则产生不可恢复变形,当达到160 MPa时蠕变曲线进入加速段;随着轴向荷载水平的增加,渗透率总体趋势先降低后增高,最小值出现在最大压密点,蠕变过程进入加速段以后渗透率急剧增大。采用FLAC3D中的Cvisc模型为蓝本,以体积应变为桥梁建立ZSI(zone state index)与渗透率的关系,自主开发了基于应变软化的改进非线性蠕变西原模型,对试验结果进行验证。数值模拟表明:靠近进水端的渗透率比出水端变化快,不同应力下ZSI值云图的破损区与试验中岩样的"V"型剪切带破坏模式基本一致,渗透率的理论曲线与计算曲线吻合较好。说明提出的模型能够很好地反映加卸载条件下岩石蠕变–渗流耦合特性和局部破坏规律。展开更多
In recent years, Z-source inverters (ZSI) have been proposed as an replacement power conversion concept which it has both voltage buck and boost abilities. In addition, ZSI doesn’t require dead-time to protection sho...In recent years, Z-source inverters (ZSI) have been proposed as an replacement power conversion concept which it has both voltage buck and boost abilities. In addition, ZSI doesn’t require dead-time to protection short circuit at two switches any of the same phase leg in the inverter bridge and to achieve optimal harmonic of current, voltage. This paper presents two different control methods (CM) for ZSI. The aim of this study to compare between two modulation methods, there are modi?ed space vector pulse width modulation method (MSVM) and the simple boost control (SBC) about the unique harmonic performance features, the total average and peak switching device power of the inverter system. In addition, this paper also analyzes about the ability exceed modulation index in linear region of two CM using MATLAB/Simulink.展开更多
To solve the disadvantages of the traditional Z-source inverter(ZSI),this paper investigates a series-type switched-inductor Z-source inverter(SSI-ZSI)topology.It not only preserves the advantages of the traditional Z...To solve the disadvantages of the traditional Z-source inverter(ZSI),this paper investigates a series-type switched-inductor Z-source inverter(SSI-ZSI)topology.It not only preserves the advantages of the traditional ZSI,but also improves the voltage gain.On the condition of the same voltage gain,the capacitor voltage stress is reduced,the soft start characteristic can be achieved and the inverter can be immune to the damage of the inrush current.The circuit structure and operating principle are analyzed in detail;the simulation model and the experimental platform are built.The simulation and experimental results verify the rationality and superiority of the circuit topology.展开更多
文摘为了研究大连多岩溶区的复杂地质条件对基坑开挖的影响,运用有限差分软件FLAC^(3D)对不同溶洞位置的基坑进行模拟,得到位移变化规律。同时利用单元安全状态评价指标ZSI(Zone State Index)对不同溶洞位置下基坑周围土体进行评价,针对影响较大区域溶洞提出合理的溶洞处理方案。研究结果表明:溶洞对基坑稳定性影响程度由大到小依次是被动区、过渡区、主动区。针对被动区溶洞采取开挖前注浆处理,通过对大连地区深基坑进行数值模拟确定的不同溶洞位置对基坑影响程度具有一定的指导意义,可为岩溶地区深基坑工程的设计与施工提供参考。
文摘Objective:To evaluate surgical outcomes after implantation of the Zephyr ZSI 475 inflatable penile prosthesis(IPP)and patients’quality of life.Methods:From December 2014 to September 2018,15 patients underwent prosthesis implantation with ZSI 475.A retrospective review of clinical data was performed.Patients’quality of life after implantation was investigated with Quality of Life and Sexuality with Penile Prosthesis(QoLSPP)questionnaire.Results:The median age of patients was 57 years and the average follow-up time was 22 months.Twelve patients received a standard implantation due to severe erectile dysfunction(ED);three patients also presented penile curvature and additional corporoplasty with grafting was necessary.Three procedures had to be interrupted due to defects of the insertion tools.In one case a manufacturing defect resulted in a pump leak.In one case,a severe postoperative complication occurred,which requested explanation of the device.During the follow-up,four patients experienced mechanical failure of the prosthesis.Results of QoLSPP questionnaire at 12 months were skewed toward the positive end of the scale in all domains.Conclusion:In our initial experience,ZSI 475 suffered a high rate of mechanical failures;on the other hand,the company showed great commitment in order to improve the quality and reliability of the device.The lower cost of ZSI 475 may add to the chances of the product to become a cost-effective alternative to treat those patient who need a IPP.
文摘针对临近暗渠的富水区基坑开挖施工复杂性,将单元状态指标ZSI(Zone State Index)和流-固耦合相结合,并采用有限差分法进行三维数值模拟分析。首先使用FLAC3D三维快速拉格朗日差分程序,建立了青岛地铁基坑的实际工程模型,依次计算求解了暗渠附近土体的垂直位移、水平位移和塑性区,进而采用ZSI方法对基坑开挖时暗渠附近土体的破坏状态以及渗透性系数进行了分析。模拟结果表明,暗渠的变形随着基坑的开挖深度的增加而增大,且靠近基坑的位置暗渠沉降位移最大值为4.15 mm,有渗流位移比无渗流位移大;基坑周围土体塑性区随开挖深度增加而增大,呈中部集中趋势;模拟计算位移值与实际监测数据变化趋势吻合,证明了模拟的正确性,且地下水的作用不可忽略。ZSI分析结果表明,随着基坑逐步开挖,暗渠附近土体的破坏范围逐渐增大,且在第三步开挖施工后,破坏区显著增大且呈中部集中趋势,渗透性系数在破坏区也相应增大。ZSI分析法将土体的破坏状态数量化,能精确直观地反映深挖基坑附近暗渠土体的破坏状态。ZSI与实测结果较为吻合,说明了单元状态指标可以对富水区邻近暗渠基坑开挖进行安全性评价与分析,为基坑施工的顺利进行提供保障。
文摘The 3Φinduction motor is a broadly used electric machine in industrial applications,which plays a vital role in industries because of having plenty of beneficial impacts like low cost and easiness but the problems like decrease in motor speed due to load,high consumption of current and high ripple occurrence of ripples have reduced its preferences.The ultimate objective of this study is to control change in motor speed due to load variations.An improved Trans Z Source Inverter(ΓZSI)with a clamping diode is employed to maintain constant input voltage,reduce ripples and voltage overshoot.To operate induction motor at rated speed,different controllers are used.The conventional Proportional-Inte-gral(PI)controller suffers from high settling time and maximum peak overshoot.To overcome these limitations,Fractional Order Proportional Integral Derivative(FOPID)controller optimized by Gray Wolf Optimization(GWO)technique is employed to provide better performance by eliminating maximum peak overshoot pro-blems.The proposed speed controller provides good dynamic response and controls the induction motor more effectively.The complete setup is implemented in MATLAB Simulation to verify the simulation results.The proposed approach provides optimal performance with high torque and speed along with less steady state error.
文摘以大东山隧道的石英岩为研究对象,进行循环加卸载条件下岩石蠕变–渗流耦合试验,分析了岩石加卸载过程中的蠕变、渗透性变化规律和渗流–蠕变耦合机理,得到压密阶段、裂纹扩展阶段和裂纹贯通阶段岩石体积应变的发展规律,总结了渗透率与体积应变之间的关系。试验表明:轴向荷载0~50 MPa为压密阶段,继续加载则产生不可恢复变形,当达到160 MPa时蠕变曲线进入加速段;随着轴向荷载水平的增加,渗透率总体趋势先降低后增高,最小值出现在最大压密点,蠕变过程进入加速段以后渗透率急剧增大。采用FLAC3D中的Cvisc模型为蓝本,以体积应变为桥梁建立ZSI(zone state index)与渗透率的关系,自主开发了基于应变软化的改进非线性蠕变西原模型,对试验结果进行验证。数值模拟表明:靠近进水端的渗透率比出水端变化快,不同应力下ZSI值云图的破损区与试验中岩样的"V"型剪切带破坏模式基本一致,渗透率的理论曲线与计算曲线吻合较好。说明提出的模型能够很好地反映加卸载条件下岩石蠕变–渗流耦合特性和局部破坏规律。
文摘In recent years, Z-source inverters (ZSI) have been proposed as an replacement power conversion concept which it has both voltage buck and boost abilities. In addition, ZSI doesn’t require dead-time to protection short circuit at two switches any of the same phase leg in the inverter bridge and to achieve optimal harmonic of current, voltage. This paper presents two different control methods (CM) for ZSI. The aim of this study to compare between two modulation methods, there are modi?ed space vector pulse width modulation method (MSVM) and the simple boost control (SBC) about the unique harmonic performance features, the total average and peak switching device power of the inverter system. In addition, this paper also analyzes about the ability exceed modulation index in linear region of two CM using MATLAB/Simulink.
文摘To solve the disadvantages of the traditional Z-source inverter(ZSI),this paper investigates a series-type switched-inductor Z-source inverter(SSI-ZSI)topology.It not only preserves the advantages of the traditional ZSI,but also improves the voltage gain.On the condition of the same voltage gain,the capacitor voltage stress is reduced,the soft start characteristic can be achieved and the inverter can be immune to the damage of the inrush current.The circuit structure and operating principle are analyzed in detail;the simulation model and the experimental platform are built.The simulation and experimental results verify the rationality and superiority of the circuit topology.
