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SRAM (Static Random Access Memory)-based FPGA (Field-Programmable Gate Array) is widely used in aircraft with its high-performance and reconfigurable characteristics. It has been proved that SRAM memory cells of the device are extremely sensitive to single particle effects of atmospheric neutrons. SEU (Single Event Upset) failure chain was proposed according to the SRAM-based FPGA three-tier architecture...
In the aircraft lightning indirect effects test, the lightning attachment points are represented by the current generator and return conductor attachments to the aircraft. The airframe and return conductors form a complex non-uniform multi-conductor transmission line. In order to analyze the distributed parameters of the coaxial return conductor system, the simplified model is built in the work to...
To improve the measurement accuracy of self-integral Rogowski coil, the ahead phenomenon of its wave peak is analyzed. To find the authentic reason of this phenomenon, the equivalent parameter model of the sampling resistor is established. Both the analysis of the equivalent parameter model and experiment results show that distributed inductance in the sampling resistor is the critical factor for...
The plastic encapsulated DC/DC converters have been widely used in data communication, oa equipment, industrial instruments etc. in these years. One of the fundamental problem which obstacle to its further application is the unreliability of the pins. In light of a batch of plastic encapsulated DC/DC converters with unweldable pins, four group contrast experiments are designed to analyze the failure...
The CTR(Current Transfer Ratio) is usually used as characterization parameters in the optocoupler ALT(Accelerated Life Test). With the adventage of high reliability components, the time of ALT becomes too long to meet the needs of engineering. The CTR degradation appears after more than a year in the accelerated test of optocoupler storage life. The low-frequency noise of optocoupler is a characterization...
Bipolar junction transistors can be used as switch transistors in satellite power system. In order to confirm that weather water vapor control and passive layer process effecting on transistor performance and Aluminum corrosion, 88 silicon NPN switching transistors with different process used in this paper. Experiments with temperature cycling and power on, the contrastive groups of which were with...
Optocoupler is widely used in the field of aerospace and military, its reliability is attached more importance Current transfer ratio (CTR) is a conventional electric parameter used to evaluate its reliability. But it can not reflect microscopic changes of device internal defects directly. In order to study the influence of defects to output noise, defects simulation of optocoupler based on low-frequency...
We can reduce the grounding resistance of grounding object by reducing the resistivity of the soil, increasing the size of the area of ground, selecting the appropriate shape of the grounding (depth of the vertical ground) and increasing the number of vertical ground, etc. However, when the spot area is limited and soil resistivity is high, traditional grounding technology is difficult to achieve...
For the needs of routing and ventilation, the enclosures of electric equipments are always with a lot of aperture. Although the sizes of these apertures are very small, electromagnetic field can be coupled in the shield while the frequency of the incident wave is relatively higher. The electromagnetic simulating software FEKO is used to analysis the influence on HIRF coupling brought by different-shaped...
The very low frequency (VLF) transmitting station can be used to provide communication underwater or on water surface with submerged submarines. And it is an important means for submarine command and communications. As the VLF transmitting antenna system has a complex structure and a large size, the radiation field may cause a potential harm on staff as well as to the public. In this paper, the United...
In order to measure the pulsed magnetic field, a pulsed magnetic field measurement system was developed in this paper, using a sensor called GMR. The output signals of this system were acquired and stored with an oscilloscope. The pulsed magnetic field measurement system was verified by experiments, with the pulsed magnetic field generated by the lightning pulsed magnetic field simulator. The results...
Analysis and evaluation on land carrying capacity is the key content of environmental impact assessment of urban master planning, even an important criterion of determining the feasibility of resource and environment in urban planning. Currently, most cities are all facing the problem of land resource shortage, land carrying capacity has become the pivotal factor for restricting the urban development,...
Grounding is one of the measures to reduce electromagnetic interference. Different cable shielded layer grounding methods are applied for different practice conditions. The variation of the induced current on the shielded cable layer is studied under different grounding methods (one-end grounding, two-end grounding equal-interval multi-point grounding) through using FEKO. The different grounding resistance...
This paper make experiments and analyze with the acquisition system of multichannel weak photocurrent for Laser particle size analyzer. It is found using analog multiplexers directly switching multi-channel photocurrent will have a pulse spike. Through the analysis of photocurrent source output port, it was found that distributed capacitance will cause a pulse spike after switch closed. Then proposed...
As nondestructive technologies, Geophysical methods have been widely used to detect the hidden trouble of dyke. However each geophysical method has not only its own advantage but also its limitations, so it is difficult to choose one from them to solve all problems from shallow to deep. This article takes advantage of high-density resistivity method to conduct a detailed detection in the shallow part...
Feng Shui is also called geomancy, ground phase—which fuses the astronomy, geography, human science, and so on and maximizing the pursuit of the heaven, the earth and the human in one—is one ancient comprehensive ecological environmentology, and continue to be used so far. We taking the residential areas for example, from the view of urban planning specifically describe the application of the ancient...
Quality of the performance and parameters of electronic devices under high-low temperature environments is one of the most important aspects for evaluating its reliability. To the problem that the junction temperature control of electronic devices is not accurate in large batch testing under high-low temperature environments, this paper establishes the junction temperature change equation with time...
Aiming at high demand of water resources and serious water pollution owing to the rapid economic development in riverside area, the paper study in optimal water resources deployment for sustainable development, through the equilibrium analysis of water supply and the coordinated development of water quality conservation. From the point of the conservation, protection of water resources, analysis the...
Large urbanized polders, are always with developed economy and concentrated population, in which the lacking river storage capacity makes the risk of flood and waterlog increase. Therefore, it's much more necessary to study more accurate method of drainage calculation and the relationship between the drainage modulus and the drainage area for the drainage strategy in urbanized polder. According to...
A small-size acceleration measurement system based on ARM is designed and developed in this paper. It adopts Micro-machined capacitive integrated chip Model1221 as sensor and SD card as Data memory. Combined with communication port, application software is designed to display, store and deal with the data measured. By measuring the centripetal acceleration of rotating body at a uniform velocity, the...
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