电涌保护器(SPD)是一种能够有效减少雷击电磁脉冲对电气、电子系统设备的危害及防御雷电灾害的装置,在防雷工程中应用十分广泛,而 SPD 的专用过电流后备保护器(SCB)技术也日趋成熟,该技术可使防雷系统更加安全可靠运行。本文根据 SPD不...电涌保护器(SPD)是一种能够有效减少雷击电磁脉冲对电气、电子系统设备的危害及防御雷电灾害的装置,在防雷工程中应用十分广泛,而 SPD 的专用过电流后备保护器(SCB)技术也日趋成熟,该技术可使防雷系统更加安全可靠运行。本文根据 SPD不同使用工况的实际应用,结合建筑物雷电分区、接线形式、设备绝缘耐冲击电压等有关要求,对 SPD 及其专用过电流后备保护器 的选型及安装进行了相关阐述及探讨。展开更多
As for ultra-low permeability reservoir,the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops.Combined with non-linear porous f...As for ultra-low permeability reservoir,the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops.Combined with non-linear porous flow characteristics,the concept of dimensionless pressure sweep efficiency and deliverability index are put forward to evaluate the physical models' well pattern adaptability.Through experiments,the models' pressure distribution is measured and on which basis,the pressure gradient fields are drawn and the porous flow regions of these models are divided into dead oil region,non-linear porous flow region,and quasi-linear porous flow region with the help of twin-core non-linear porous flow curve.The results indicate that rectangular well pattern in fracture reservoirs has the best adaptability,while the worst is inverted nine-spot equilateral well pattern.With the increase of drawdown pressure,dead oil region decreases,pressure sweep efficiency and deliverability index increase; meantime,the deliverability index of rectangular well pattern has much more rational increase.Under the same drawdown pressure,the rectangular well pattern has the largest pressure sweep efficiency.展开更多
The investigation of the interplay between geometry and nonlinearity may open the road to the control of extreme waves. We study three-dimensional localization and dispersive shocks in a bent cigar shaped potential by...The investigation of the interplay between geometry and nonlinearity may open the road to the control of extreme waves. We study three-dimensional localization and dispersive shocks in a bent cigar shaped potential by the nonlinear Schro¨ dinger equation. At high bending and high nonlinearity, topological trapping is frustrated by the generation of curved wave-breaking. Four-dimensional parallel simulations confirm the theoretical model. This work may contribute to novel devices based on geometrically constrained highly nonlinear dynamics and tests and analogs of fundamental physical theories in curved space.展开更多
文摘电涌保护器(SPD)是一种能够有效减少雷击电磁脉冲对电气、电子系统设备的危害及防御雷电灾害的装置,在防雷工程中应用十分广泛,而 SPD 的专用过电流后备保护器(SCB)技术也日趋成熟,该技术可使防雷系统更加安全可靠运行。本文根据 SPD不同使用工况的实际应用,结合建筑物雷电分区、接线形式、设备绝缘耐冲击电压等有关要求,对 SPD 及其专用过电流后备保护器 的选型及安装进行了相关阐述及探讨。
基金Project(2011ZX05013-006)supported by the National Science and Technology Project of China
文摘As for ultra-low permeability reservoir,the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops.Combined with non-linear porous flow characteristics,the concept of dimensionless pressure sweep efficiency and deliverability index are put forward to evaluate the physical models' well pattern adaptability.Through experiments,the models' pressure distribution is measured and on which basis,the pressure gradient fields are drawn and the porous flow regions of these models are divided into dead oil region,non-linear porous flow region,and quasi-linear porous flow region with the help of twin-core non-linear porous flow curve.The results indicate that rectangular well pattern in fracture reservoirs has the best adaptability,while the worst is inverted nine-spot equilateral well pattern.With the increase of drawdown pressure,dead oil region decreases,pressure sweep efficiency and deliverability index increase; meantime,the deliverability index of rectangular well pattern has much more rational increase.Under the same drawdown pressure,the rectangular well pattern has the largest pressure sweep efficiency.
基金the support of a grant from the John Templeton Foundation(58277)support by the European Research Council Grant ERC-POC-2014 Vanguard(664782)
文摘The investigation of the interplay between geometry and nonlinearity may open the road to the control of extreme waves. We study three-dimensional localization and dispersive shocks in a bent cigar shaped potential by the nonlinear Schro¨ dinger equation. At high bending and high nonlinearity, topological trapping is frustrated by the generation of curved wave-breaking. Four-dimensional parallel simulations confirm the theoretical model. This work may contribute to novel devices based on geometrically constrained highly nonlinear dynamics and tests and analogs of fundamental physical theories in curved space.
