Magnetic-valve controllable reactor(MCR)has characteristics of DC bias and different types of magnetic flux density in the magnetic circuit and winding current distortion.These characteristics not only lead to loss ca...Magnetic-valve controllable reactor(MCR)has characteristics of DC bias and different types of magnetic flux density in the magnetic circuit and winding current distortion.These characteristics not only lead to loss calculation method of MCR different from that of power transformer,but also make it more difficult to calculate the core loss and wingding loss of MCR accurately.Our study combines core partition method with dynamic inverse J-A model to calculate the core loss of MCR.The winding loss coefficient of MCR is proposed,which takes into account the influence of harmonics and magnetic flux leakage on the winding loss of MCR.The result shows that the proposed core loss calculation method and winding loss coefficient are effective and correct for the loss calculation of MCR.展开更多
A SPICE sub-circuit model is developed for high-voltage LDMOS transistors integrated in PDP driver ICs. The model accounts for intrinsic LDMOS phenomena such as the quasi-saturation effects, voltage-dependent drift re...A SPICE sub-circuit model is developed for high-voltage LDMOS transistors integrated in PDP driver ICs. The model accounts for intrinsic LDMOS phenomena such as the quasi-saturation effects, voltage-dependent drift resistance, self-heating effects, and Miller capacitance. In contrast to most physical or sub-circuit models, the proposed model not only provides precise simulated results,but also brings a very fast modeling procedure. Furthermore,the model also can be embedded in a commercial SPICE simulator easily. The simulation results using the presented models agree well with the measured ones and the error is less than 5%.展开更多
A 109.9 m ice core was extracted at a location about 300 m away from the Dome A summit （80°00′S, 77°21″E） by the Chinese team of the International Trans-Antarctic Science Expedition （ITASE） during the ...A 109.9 m ice core was extracted at a location about 300 m away from the Dome A summit （80°00′S, 77°21″E） by the Chinese team of the International Trans-Antarctic Science Expedition （ITASE） during the 21st Chinese National Antarctica Research Expedition （CHINARE） in January 2005. Two independent methods were used for dating the ice core, volcanic event markers shown by prominent non-sea-salt sulfate （nss-SO4^2-） and the Herron and Langway （H-L） firn densification model. Six promi- nent volcanic events （Agung 1963 AD, Tambora 1815 AD, Kuwae 1453 AD, Unknown 1259 AD, Taupo 186 AD and Pinatubo 1050 BC） were identified by comparison with other Antarctic ice cores. Based on the mean accumulation rates be- tween adjacent events, we estimate the age at the tim pore close-off depth （102 m） was 3516±100 a BP. This is the oldest close-off age ever reported from the Antarctic and the Greenland ice sheets. Calculations using the H-L model show that the age at the same depth is 3581±100 a BP. The two dating techniques differ by 65 years, or -1.8% of the record. We calculated the bottom age of the ice core as 4009±150 a BP using the volcanic dating method and 4115±150 a BP using the H-L model method.展开更多
基金National Natural Science Foundation of China(No.51367010)Science and Technology Program of Gansu Province(No.17JR5RA083)Program for Excellent Team of Scientific Research in Lanzhou Jiaotong University(No.201701)。
文摘Magnetic-valve controllable reactor(MCR)has characteristics of DC bias and different types of magnetic flux density in the magnetic circuit and winding current distortion.These characteristics not only lead to loss calculation method of MCR different from that of power transformer,but also make it more difficult to calculate the core loss and wingding loss of MCR accurately.Our study combines core partition method with dynamic inverse J-A model to calculate the core loss of MCR.The winding loss coefficient of MCR is proposed,which takes into account the influence of harmonics and magnetic flux leakage on the winding loss of MCR.The result shows that the proposed core loss calculation method and winding loss coefficient are effective and correct for the loss calculation of MCR.
基金the National High Technology Research and Development Program of China(No.2004AA1Z1060)~~
文摘A SPICE sub-circuit model is developed for high-voltage LDMOS transistors integrated in PDP driver ICs. The model accounts for intrinsic LDMOS phenomena such as the quasi-saturation effects, voltage-dependent drift resistance, self-heating effects, and Miller capacitance. In contrast to most physical or sub-circuit models, the proposed model not only provides precise simulated results,but also brings a very fast modeling procedure. Furthermore,the model also can be embedded in a commercial SPICE simulator easily. The simulation results using the presented models agree well with the measured ones and the error is less than 5%.
基金supported by National Natural Scientific Foundation of China (Grant Nos.40776002,40825017,41171052)the Hundred Talent Project of Chinese Academy of Sciences,the Polar Scientific Explore Organizing Committee Foundation (Grant Nos. 20080202,0852H71001)State Oceanic Administration of People’s Republic of China Project on Climate in Polar Regions (Grant Nos.CHINARE2012-04-04 and CHINARE2012- 02-02)
文摘A 109.9 m ice core was extracted at a location about 300 m away from the Dome A summit （80°00′S, 77°21″E） by the Chinese team of the International Trans-Antarctic Science Expedition （ITASE） during the 21st Chinese National Antarctica Research Expedition （CHINARE） in January 2005. Two independent methods were used for dating the ice core, volcanic event markers shown by prominent non-sea-salt sulfate （nss-SO4^2-） and the Herron and Langway （H-L） firn densification model. Six promi- nent volcanic events （Agung 1963 AD, Tambora 1815 AD, Kuwae 1453 AD, Unknown 1259 AD, Taupo 186 AD and Pinatubo 1050 BC） were identified by comparison with other Antarctic ice cores. Based on the mean accumulation rates be- tween adjacent events, we estimate the age at the tim pore close-off depth （102 m） was 3516±100 a BP. This is the oldest close-off age ever reported from the Antarctic and the Greenland ice sheets. Calculations using the H-L model show that the age at the same depth is 3581±100 a BP. The two dating techniques differ by 65 years, or -1.8% of the record. We calculated the bottom age of the ice core as 4009±150 a BP using the volcanic dating method and 4115±150 a BP using the H-L model method.
