This paper presents a novel precision delay circuit design for high-speed data acquisition systems. Many studies have suggested that various advanced electronic measurement apparatuses require that the delay circuit s...This paper presents a novel precision delay circuit design for high-speed data acquisition systems. Many studies have suggested that various advanced electronic measurement apparatuses require that the delay circuit should have a high precision and a short delay interval. Practically, however, such measurement apparatuses are low in preci- sion and long in delay interval at present. The structure and function of a data acquisition system is introduced first; then the principle of ramp-based precision delay circuits and the digitally programmable delay generator is studied and the precision delay circuit is designed. The authors also demonstrated 8-bit programmable delay circuits with a timing pre- cision of 10 ps. Therefore the programmable precision delay circuit here presented has a higher precision, shorter inter- val and more detectable function than any other precision delay circuit.展开更多
Authors developed a highly effective brushless DC motor with a simple operation principle. If the operation principle of the motor is simple, a drive circuit will also become simple and its production cost will be low...Authors developed a highly effective brushless DC motor with a simple operation principle. If the operation principle of the motor is simple, a drive circuit will also become simple and its production cost will be lower. From the above fact, Minato motor was noticed. In this motor, a unidirectional current flows in the electromagnets. In other words, unidirectional windings are used. In this motor, only strong repulsive force is utilized when a permanent magnet of a rotor and an electromagnet of a stator are adjacent. Hence, torque constant becomes higher and the efficiency of the motor is high. However, an effective value of the electromagnetic current increases because a large current flows in a short period. Therefore, copper loss increases and the efficiency of the motor decreases. In order to solve above defects, a new motor is proposed. From the experiment, it is clarified that the efficiency of the proposed motor is higher than that of the commercial motors.展开更多
Business Directory defines economic power as ＂conditions of having sufficient productive resources at command that give the capacity to make and enforce economic decisions, such as allocation of resources and apporti...Business Directory defines economic power as ＂conditions of having sufficient productive resources at command that give the capacity to make and enforce economic decisions, such as allocation of resources and apportioning of goods and services＂. This qualitative definition may be sufficient for general discussions, but it does not offer any quantitative measurements for management and control. Is there a way to measure economic power for analysis and synthesis of economic systems in this 21st century？ This paper answers this question by introducing a set of quantitative terms from the field of electrical engineering, used in power measurement and control of electrical systems. Circuit theory concepts are introduced to show how the relationship between cash and cash flow in finance is analogous to that of electric charge and electric current and how education level, as economic potential, is analogous to electrical potential that causes current to flow in a circuit. An individual is identified as the basic cash flow source in the economy. Circuit models for an individual as well as a typical production facility are developed and demonstrated with an example. Equations for the measurement of economic power, losses, efficiency, and power factor are presented. It is shown that the individuals are the basic cash flow sources and producers of economic power.展开更多
Graphene is a promising material as both active components and additives in electrochemical energy storage devices. The properties of graphene strongly depend on the fabrication methods. The applications of reduced gr...Graphene is a promising material as both active components and additives in electrochemical energy storage devices. The properties of graphene strongly depend on the fabrication methods. The applications of reduced graphene oxide as electrode materials have been well studied and reviewed, but the using of "pristine" graphene as electrode material for energy storage is still a new topic. In this paper, we review state-of-the-art progress in the fabrication of "pristine" graphene by different methods and the electrochemical performance of graphene-based electrodes. The achievements in this area will be summarized and compared with the graphene oxide route in terms of cost, scalability, material properties and performances, and the challenges in these methods will be discussed as well.展开更多
Harvesting mechanical energy from our surroundings to acquire a steady and high power output has attracted intensive interest due to the fast development of portable electronics. In this work the disk-structured tribo...Harvesting mechanical energy from our surroundings to acquire a steady and high power output has attracted intensive interest due to the fast development of portable electronics. In this work the disk-structured triboelectric nanogenerator （TENG） was prepared based on the mature printed drcuit board （PCB） technology and the composite structure for effectively improving the utilization in space. A narrow grating of 1~ was designed to produce high output. Operated at a rotation rate of 1,000 rpm, the TENG produces a high output power density of 267 mW/cm2 （total power output of 25.7 W） at a matched load of 0.93 MfZ After introducing a transformer, the output power can be managed so that it can be directly used to charge a battery for a smart phone. With the PCB production technology, fabrication of high performance TENG at low cost and large-scale becomes feasible.展开更多
文摘This paper presents a novel precision delay circuit design for high-speed data acquisition systems. Many studies have suggested that various advanced electronic measurement apparatuses require that the delay circuit should have a high precision and a short delay interval. Practically, however, such measurement apparatuses are low in preci- sion and long in delay interval at present. The structure and function of a data acquisition system is introduced first; then the principle of ramp-based precision delay circuits and the digitally programmable delay generator is studied and the precision delay circuit is designed. The authors also demonstrated 8-bit programmable delay circuits with a timing pre- cision of 10 ps. Therefore the programmable precision delay circuit here presented has a higher precision, shorter inter- val and more detectable function than any other precision delay circuit.
文摘Authors developed a highly effective brushless DC motor with a simple operation principle. If the operation principle of the motor is simple, a drive circuit will also become simple and its production cost will be lower. From the above fact, Minato motor was noticed. In this motor, a unidirectional current flows in the electromagnets. In other words, unidirectional windings are used. In this motor, only strong repulsive force is utilized when a permanent magnet of a rotor and an electromagnet of a stator are adjacent. Hence, torque constant becomes higher and the efficiency of the motor is high. However, an effective value of the electromagnetic current increases because a large current flows in a short period. Therefore, copper loss increases and the efficiency of the motor decreases. In order to solve above defects, a new motor is proposed. From the experiment, it is clarified that the efficiency of the proposed motor is higher than that of the commercial motors.
文摘Business Directory defines economic power as ＂conditions of having sufficient productive resources at command that give the capacity to make and enforce economic decisions, such as allocation of resources and apportioning of goods and services＂. This qualitative definition may be sufficient for general discussions, but it does not offer any quantitative measurements for management and control. Is there a way to measure economic power for analysis and synthesis of economic systems in this 21st century？ This paper answers this question by introducing a set of quantitative terms from the field of electrical engineering, used in power measurement and control of electrical systems. Circuit theory concepts are introduced to show how the relationship between cash and cash flow in finance is analogous to that of electric charge and electric current and how education level, as economic potential, is analogous to electrical potential that causes current to flow in a circuit. An individual is identified as the basic cash flow source in the economy. Circuit models for an individual as well as a typical production facility are developed and demonstrated with an example. Equations for the measurement of economic power, losses, efficiency, and power factor are presented. It is shown that the individuals are the basic cash flow sources and producers of economic power.
基金supported by the National Natural Science Foundation of China(Grant Nos.51125009&91434118)the National Natural Science Foundation for Creative Research Group(Grant No.21221061)the Hundred Talents Program of the Chinese Academy of Sciences
文摘Graphene is a promising material as both active components and additives in electrochemical energy storage devices. The properties of graphene strongly depend on the fabrication methods. The applications of reduced graphene oxide as electrode materials have been well studied and reviewed, but the using of "pristine" graphene as electrode material for energy storage is still a new topic. In this paper, we review state-of-the-art progress in the fabrication of "pristine" graphene by different methods and the electrochemical performance of graphene-based electrodes. The achievements in this area will be summarized and compared with the graphene oxide route in terms of cost, scalability, material properties and performances, and the challenges in these methods will be discussed as well.
文摘Harvesting mechanical energy from our surroundings to acquire a steady and high power output has attracted intensive interest due to the fast development of portable electronics. In this work the disk-structured triboelectric nanogenerator （TENG） was prepared based on the mature printed drcuit board （PCB） technology and the composite structure for effectively improving the utilization in space. A narrow grating of 1~ was designed to produce high output. Operated at a rotation rate of 1,000 rpm, the TENG produces a high output power density of 267 mW/cm2 （total power output of 25.7 W） at a matched load of 0.93 MfZ After introducing a transformer, the output power can be managed so that it can be directly used to charge a battery for a smart phone. With the PCB production technology, fabrication of high performance TENG at low cost and large-scale becomes feasible.
