针对封闭式变电站中高压电缆在进行交流耐压同步局部放电测量试验时,试验引线通道紧张,无法安全连接试验设备的问题,设计了一套高压电缆交流耐压同步局放测量的试验引线系统。采用理论计算、仿真分析与试验的方式,开发一种小型化、轻量...针对封闭式变电站中高压电缆在进行交流耐压同步局部放电测量试验时,试验引线通道紧张,无法安全连接试验设备的问题,设计了一套高压电缆交流耐压同步局放测量的试验引线系统。采用理论计算、仿真分析与试验的方式,开发一种小型化、轻量化、整体预制与多次重复插拔式的220 k V高压电缆试验终端,以及能够实现柔性化、轻量化、多次重复收放的220 k V试验电缆。并在南京地区某220 k V电缆线路工程交接试验中进行了现场的应用验证,为开展高效安全的高压电缆交接试验,提高试验的可靠性与可操作性,提供了有利的技术支持与保障。展开更多
Verlinde has suggested that the gravity has an entropic origin, and a gravitational system could be regarded as a thermodynarnical system. It is well-known that the equipartition law of energy is invalid at very low t...Verlinde has suggested that the gravity has an entropic origin, and a gravitational system could be regarded as a thermodynarnical system. It is well-known that the equipartition law of energy is invalid at very low temperature. Therefore, entropic force should be modified while the temperature of the holographic screen is very low. It is shown that the modified entropic force is proportional to the square of the acceleration, while the temperature of the holographic screen is much lower than the Debye temperature TD. The modified entropic force returns to the Newton＇s law of gravitation while the temperature of the holographic screen is much higher than the Debye temperature. The modified entropic force is connected with modified Newtonian dynamics （MOND）. The constant ao involved in MOND is linear in the Debye frequency WD, which can be regarded as the largest frequency of the bits in screen. We find that there do have a strong connection between MOND and cosmology in the framework of Verlinde＇s entropic force, if the holographic screen is taken to be bound of the Universe. The Debye frequency is linear in the Hubble constant Ho.展开更多
A novel MEMS device boning system is presented. Aiming at the high velocity, high precision and high flexibility requirements, a novel manipulator of planar parallel structure is developed to substitute ordinary X-Y t...A novel MEMS device boning system is presented. Aiming at the high velocity, high precision and high flexibility requirements, a novel manipulator of planar parallel structure is developed to substitute ordinary X-Y table. In addition, the machine vision is implemented to improve the system＇ s flexibility. The initial angular positions of the joints are estimated by the extended Kalman filter algorithm. As a resuh, the manipulator＇s absolute locating accuracy in its workspace is guaranteed indirectly. For any MEMS device, the bonding system itself can be used as measurement equipment to create the device＇ s geometry model, which is the base to do off-line programming. A quite ideal trade-off between the system＇ s flexibility and efficiency is got. Finally, some verified motion specification of the manipulator, the bonding experimental results and the verified qualities of the bonded devices are provided.展开更多
Studied in this paper is a(2+1)-dimensional coupled nonlinear Schr?dinger system with variable coefficients,which describes the propagation of an optical beam inside the two-dimensional graded-index waveguide amplifie...Studied in this paper is a(2+1)-dimensional coupled nonlinear Schr?dinger system with variable coefficients,which describes the propagation of an optical beam inside the two-dimensional graded-index waveguide amplifier with the polarization effects. According to the similarity transformation, we derive the type-Ⅰ and type-Ⅱ rogue-wave solutions. We graphically present two types of the rouge wave and discuss the influence of the diffraction parameter on the rogue waves.When the diffraction parameters are exponentially-growing-periodic, exponential, linear and quadratic parameters, we obtain the periodic rogue wave and composite rogue waves respectively.展开更多
This paper is focused on the H_(∞) control problem for linear systems with interval timevarying delays.By employing a reciprocally convex combination approach and a delay decomposition approach,some new delay-depende...This paper is focused on the H_(∞) control problem for linear systems with interval timevarying delays.By employing a reciprocally convex combination approach and a delay decomposition approach,some new delay-dependent bounded real lemmas(BRLs) are derived such that the closedloop system is asymptotically stable with a prescribed H_(∞) level.The BRLs are then used to solve the H_(∞) controller design by incorporating with the cone complementary approach.Three numerical examples are finally given to show the validity of the proposed method.展开更多
文摘针对封闭式变电站中高压电缆在进行交流耐压同步局部放电测量试验时,试验引线通道紧张,无法安全连接试验设备的问题,设计了一套高压电缆交流耐压同步局放测量的试验引线系统。采用理论计算、仿真分析与试验的方式,开发一种小型化、轻量化、整体预制与多次重复插拔式的220 k V高压电缆试验终端,以及能够实现柔性化、轻量化、多次重复收放的220 k V试验电缆。并在南京地区某220 k V电缆线路工程交接试验中进行了现场的应用验证,为开展高效安全的高压电缆交接试验,提高试验的可靠性与可操作性,提供了有利的技术支持与保障。
基金Supported by the National Natural Science Foundation of China under Grant Nos.10525522 and 10875129
文摘Verlinde has suggested that the gravity has an entropic origin, and a gravitational system could be regarded as a thermodynarnical system. It is well-known that the equipartition law of energy is invalid at very low temperature. Therefore, entropic force should be modified while the temperature of the holographic screen is very low. It is shown that the modified entropic force is proportional to the square of the acceleration, while the temperature of the holographic screen is much lower than the Debye temperature TD. The modified entropic force returns to the Newton＇s law of gravitation while the temperature of the holographic screen is much higher than the Debye temperature. The modified entropic force is connected with modified Newtonian dynamics （MOND）. The constant ao involved in MOND is linear in the Debye frequency WD, which can be regarded as the largest frequency of the bits in screen. We find that there do have a strong connection between MOND and cosmology in the framework of Verlinde＇s entropic force, if the holographic screen is taken to be bound of the Universe. The Debye frequency is linear in the Hubble constant Ho.
基金Supported by the High Technology Research and Development Programme of China （No. 2003AA404060） and the National Natural Science Foundation of China （No.60405008）.
文摘A novel MEMS device boning system is presented. Aiming at the high velocity, high precision and high flexibility requirements, a novel manipulator of planar parallel structure is developed to substitute ordinary X-Y table. In addition, the machine vision is implemented to improve the system＇ s flexibility. The initial angular positions of the joints are estimated by the extended Kalman filter algorithm. As a resuh, the manipulator＇s absolute locating accuracy in its workspace is guaranteed indirectly. For any MEMS device, the bonding system itself can be used as measurement equipment to create the device＇ s geometry model, which is the base to do off-line programming. A quite ideal trade-off between the system＇ s flexibility and efficiency is got. Finally, some verified motion specification of the manipulator, the bonding experimental results and the verified qualities of the bonded devices are provided.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11772017,11272023,and 11471050the Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications),China(IPOC:2017ZZ05)the Fundamental Research Funds for the Central Universities of China under Grant No.2011BUPTYB02
文摘Studied in this paper is a(2+1)-dimensional coupled nonlinear Schr?dinger system with variable coefficients,which describes the propagation of an optical beam inside the two-dimensional graded-index waveguide amplifier with the polarization effects. According to the similarity transformation, we derive the type-Ⅰ and type-Ⅱ rogue-wave solutions. We graphically present two types of the rouge wave and discuss the influence of the diffraction parameter on the rogue waves.When the diffraction parameters are exponentially-growing-periodic, exponential, linear and quadratic parameters, we obtain the periodic rogue wave and composite rogue waves respectively.
基金supported by the National Nature Science Foundation of China under Grant No.61203136the Natural Science Foundation of Hunan Province of China Grant Nos.2015JJ5021 and 2015JJ3064the Construct Program of the Key Discipline in Hunan Province
文摘This paper is focused on the H_(∞) control problem for linear systems with interval timevarying delays.By employing a reciprocally convex combination approach and a delay decomposition approach,some new delay-dependent bounded real lemmas(BRLs) are derived such that the closedloop system is asymptotically stable with a prescribed H_(∞) level.The BRLs are then used to solve the H_(∞) controller design by incorporating with the cone complementary approach.Three numerical examples are finally given to show the validity of the proposed method.
