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A Sallen-Key low-pass filter configuration with improved stop-band attenuation is presented. The proposed configuration simply connects an additional capacitor which is in parallel to the filter's output to effectively reduce the high-frequency impedance and consequently the undesired high-frequency feedthrough. The relationship between the additional capacitor and high-frequency feedthrough is also...
Contact resistance between a carbon nanotube and a metal is governed by the structure of the contact. In order to investigate an effect of the contact structure between a multi-walled carbon nanotube (MWNT) and the metal on electric properties, we studied the structural change of the contact region during the passage of a current by in-situ transmission electron microscopy with the simultaneous current...
To measure high-current, contacting with the wire directly is a certain danger. This article describes a pincer current transformer what the principle of electromagnetic induction be used in, using non-contact of the current measurement methods. In addition, the current strength meter site may not be the city's conditions. In this paper, CPU used in this design of instruments is made by the U.S. company...
The paper investigates the relationship between R&D investment choice and accounting flexibility in China for the first time by using empirical method. The results indicate that managers are more likely to cut R&D investments when the accounting flexibility is low, which means Chinese managers use R&D investment as a tool for real earnings management. Our results are consistent with theoretical...
A testing device for torque extraction generator based on IPC is presented in this paper. It may be automatic and manual operating. Its hardware adopts industry PC, multifunction cards, communication card, kinds of sensor and electric equipment. The brushless dc motor is adopted as the drive electrical machinery. Its software is Windows XP and LabView technology. It can measure voltage, current, power,...
By analyzing the subjects and objects, as well as the targets, we suggest that indicators of performance evaluation should be chosen from two fields, financial and non-financial. Financial indicators are chosen from such types as profitability, solvency, operational capacity and developing capacity, while non-financial indicators are from development and innovation, human resource, industry impact...
It is one of the highlights in the third revision of overall land use planning in China that strengthens the planning management, guarantees the land use and realizes the goal of the planning. This paper introduces the systems of the management measures for implementation of the land use planning in China, land use planning guidelines and its essence, makes systematic analysis to some prominent problems...
The operation of medical insurance in Dalian has been stable since the implement of "Dalian Urban Employee Basic Medical Insurance Measure". However, some problems, such as huge fund cash surplus and incomplete covering, still exist. The purpose of this paper is to establish the predictive model of balance between income and expenditure of medical insurance fund, whose factors are policy...
As a means of continuous improvement for the existing process, 6σ is more and more popular to enterprises. The purpose and the main implementing methods in all phases of DMAIC model of 6σ are introduced. The difference between the process capability index and the process performance index is analyzed. The significance of the application of process capability analysis in measurement phase is discussed...
While the insensitive of new slapper detonator ensuring the security, it proposes some special requirements on initiating conditions that metal foil may detonate in specific high voltage and high impulse current. But generation of high impulse current increases not only the technical difficulty of the power, but also the volume, power consumption and cost of the entire system. This article presents...
Earning is one of the most important accounting information disclosed by the enterprises, particularly in the capital market environment, as well as the medium-term annual earnings figures in the report are one of the most important information transferred by listed companies to investors. Now in financial theory, the assessment models often predict and analyze a company's value based on accounting...
This paper presents a novel method to detect the volt-ampere characteristic of vacuum arc. Highlights of this paper can be concluded that: the basic structure, computation models, designing principles and procedure, and selection criterions of materiel and electromagnetic parameters of the coil are analyzed respectively. The main clue of this paper is the operating principles of the Rogowski Coil...
This paper presents a new technique for online identification of an induction motor rotor time constant. The technique is designed for a shaft-sensorless indirect field-oriented control induction motor drive with a model reference adaptive system (MRAS)-based speed estimator. The MRAS estimator is sensitive to the changes in the rotor time constant, and on line identification of that parameter is...
This paper presents a new protection scheme for AC zonal distribution system proposed for future marine power systems based on active impedance estimation. This technique actively imposes small transient disturbances onto the system at a point of measurement to excite the system in real time and estimate the system impedance over a broad frequency range at that point. The identified impedance can...
Economical and ecological motives are pushing shoreside power supply by power electronics systems for merchant ships as well as for cruise ships. Also, final tests of on-ship power systems and generation are simplified considerably. Fault scenarios on-ship and within the harbour grid and the variability of the parameters of on-ship distribution - each ship is special, and large consumers or generators...
Magnetic field emissions extending from low frequency to several MHz are the main electromagnetic phenomenon that characterize the emissions of electrified traction lines. In this paper a general model is proposed based on Biot-Savart law as a low frequency approximation and Hertzian dipole equations for the extension to the high frequency range. The current in the line conductors are computed with...
Aeroplane design is defined by many objectives. One of them is the reduction of weight while maintaining safety, functions and performance. As power measurement campaigns have revealed, weight can be saved, as the electrical system exhibits low capacity utilisation. This is, as there are many requirements (on certification, safety and function) to meet. Also, there are systems, which do not exhibit...
The method of energy feedback by using SVPWM control algorithm for three-level inverter is proposed. So how to apply SVPWM for three-level into inverter is analyzed. How to calculate the dwell time of voltage vector and how to know region of preference vector by using the judgment on two-level are acquired. Then achievement of PWM sequence is analyzed, and some PWM sequences are mended in order to...
Recent aircraft include a sea of electric and electronic systems. These systems are very important to ensure right function of other systems and whole aircraft. Every electric facility needs suitable power supply unit. Because of that power supply unit is most important for electric systems, pilot of the aircraft or operator of the unmanned air vehicle need to know status of power supply unit. The...
A major demand of the aviation industry is the reduction of emissions in combination with cost efficiency improvement. One possible approach to face this challenge is the replacement of the conventional auxiliary power unit by a fuel cell system within a “more electric aircraft” design. In order to integrate a fuel cell system into the grid architecture of modern aircraft new protection arrangements...
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