深入探讨了不间断供电电源(uninterruptable power system,UPS)的工作原理,包括其基本功能和多种工作方式的详细说明。首先,阐述了UPS如何在电源中断时保证关键设备持续供电,及其内部如何进行直流电与交流电之间的转换。其次,分析了不...深入探讨了不间断供电电源(uninterruptable power system,UPS)的工作原理,包括其基本功能和多种工作方式的详细说明。首先,阐述了UPS如何在电源中断时保证关键设备持续供电,及其内部如何进行直流电与交流电之间的转换。其次,分析了不同类型的UPS工作模式,涵盖了备用式、在线式和在线互动式UPS,并解释了其各自的适用场景与优势。在日常维护部分,提出了一系列重要的维护要点,确保UPS的可靠性与效能。维护策略分为使用环境的维护、主机系统的日常维护以及蓄电池的日常维护3个主要方面,希望为从业人员提供一定的参考。展开更多
A high precision, high antijamming multipoint infrared telemetry system was developed to measure the piston temperature in internal combustion engine. The temperature at the measuring point is converted into correspon...A high precision, high antijamming multipoint infrared telemetry system was developed to measure the piston temperature in internal combustion engine. The temperature at the measuring point is converted into corresponding voltage signal by the thermo-couple first. Then after the V/F stage, the voltage signal is converted into the frequency signal to drive the infrared light-emitting diode to transmit infrared pulses. At the receiver end, a photosensitive audion receives the infrared pulses. After conversion, the voltage recorded by the receiver stands for the magnitude of temperature at the measuring point. Test results of the system indicate that the system is practical and the system can perform multipoint looping temperature measurements for the piston.展开更多
Submicro α-Fe2O3 coatings were formed using electrophoretic deposition(EPD) technique in aqueous media. The zeta potentials of different α-Fe2O3 suspensions with different additives were measured as a function of p ...Submicro α-Fe2O3 coatings were formed using electrophoretic deposition(EPD) technique in aqueous media. The zeta potentials of different α-Fe2O3 suspensions with different additives were measured as a function of p H to identify the optimum suspension condition for deposition. Electrophoretic depositions of α-Fe2O3 coatings under different applied electric fields and deposition time were studied and the effects of applied voltages and deposition time on deposition rates and thicknesses were investigated. The particle packing densities of the deposits at various applied voltages and deposition time were also analyzed by a scanning electron microscope(SEM). The results show that crack-free α-Fe2O3 coatings with uniform microstructure and good adherence to the nickel substrates are successfully obtained. Electrophoretic deposited α-Fe2O3 coating from aqueous suspension is a feasible, low-cost and environmental friendly method.展开更多
GaN PIN betavoltaic nuclear batteries are demonstrated in this work. GaN epitaxial layers were grown on 2-inch sapphire sub-strates by MOCVD, and then the GaN PIN nuclear batteries were fabricated. Current-voltage （...GaN PIN betavoltaic nuclear batteries are demonstrated in this work. GaN epitaxial layers were grown on 2-inch sapphire sub-strates by MOCVD, and then the GaN PIN nuclear batteries were fabricated. Current-voltage （l-V） characteristic shows that the small leakage currents are 0.12 nA at 0 V and 1.76 nA at -10 V, respectively. With 147Pm the irradiation source, the maximum open circuit voltage and maximum short circuit current are 1.07 V and 0.554 nA, respectively. The fill factor （FF） of 24.7% for the battery was been obtained. The limited performance of the devices is mainly due to the low energy deposition in the microbatteries. Therefore, the GaN nuclear microbatteries are expected to be optimized by growing high quality GaN films, thin dead layer and so on.展开更多
文摘深入探讨了不间断供电电源(uninterruptable power system,UPS)的工作原理,包括其基本功能和多种工作方式的详细说明。首先,阐述了UPS如何在电源中断时保证关键设备持续供电,及其内部如何进行直流电与交流电之间的转换。其次,分析了不同类型的UPS工作模式,涵盖了备用式、在线式和在线互动式UPS,并解释了其各自的适用场景与优势。在日常维护部分,提出了一系列重要的维护要点,确保UPS的可靠性与效能。维护策略分为使用环境的维护、主机系统的日常维护以及蓄电池的日常维护3个主要方面,希望为从业人员提供一定的参考。
文摘A high precision, high antijamming multipoint infrared telemetry system was developed to measure the piston temperature in internal combustion engine. The temperature at the measuring point is converted into corresponding voltage signal by the thermo-couple first. Then after the V/F stage, the voltage signal is converted into the frequency signal to drive the infrared light-emitting diode to transmit infrared pulses. At the receiver end, a photosensitive audion receives the infrared pulses. After conversion, the voltage recorded by the receiver stands for the magnitude of temperature at the measuring point. Test results of the system indicate that the system is practical and the system can perform multipoint looping temperature measurements for the piston.
基金Project(51021063)supported by the National Natural Science Foundation for Innovation Group of ChinaProject(2012M521540)supported by China Postdoctoral Science Foundation+1 种基金Project(2013RS4027)supported by the Post Doctoral Scientific Foundation of Hunan Province,ChinaProject(CSUZC2013023)supported by the Precious Apparatus Open Share Foundation of Central South University,China
文摘Submicro α-Fe2O3 coatings were formed using electrophoretic deposition(EPD) technique in aqueous media. The zeta potentials of different α-Fe2O3 suspensions with different additives were measured as a function of p H to identify the optimum suspension condition for deposition. Electrophoretic depositions of α-Fe2O3 coatings under different applied electric fields and deposition time were studied and the effects of applied voltages and deposition time on deposition rates and thicknesses were investigated. The particle packing densities of the deposits at various applied voltages and deposition time were also analyzed by a scanning electron microscope(SEM). The results show that crack-free α-Fe2O3 coatings with uniform microstructure and good adherence to the nickel substrates are successfully obtained. Electrophoretic deposited α-Fe2O3 coating from aqueous suspension is a feasible, low-cost and environmental friendly method.
基金supported by the National Natural Science Foundation of China(Grant No.10875084)the Natural Science Foundation of Jiangsu Province(Grant No.BK2008174)+2 种基金the Applied Science Foundation of Suzhou(Grant No.SYJG0915)the National Basic Research Program of China(Grant No.G2009CB929300)supported by Department of Nuclear Science and Engineering,Nanjing University of Aeronautics and Astronautics
文摘GaN PIN betavoltaic nuclear batteries are demonstrated in this work. GaN epitaxial layers were grown on 2-inch sapphire sub-strates by MOCVD, and then the GaN PIN nuclear batteries were fabricated. Current-voltage （l-V） characteristic shows that the small leakage currents are 0.12 nA at 0 V and 1.76 nA at -10 V, respectively. With 147Pm the irradiation source, the maximum open circuit voltage and maximum short circuit current are 1.07 V and 0.554 nA, respectively. The fill factor （FF） of 24.7% for the battery was been obtained. The limited performance of the devices is mainly due to the low energy deposition in the microbatteries. Therefore, the GaN nuclear microbatteries are expected to be optimized by growing high quality GaN films, thin dead layer and so on.
