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赵国良 《卫星电视与宽带多媒体》2007,(23):46-49
按预定计划,日本BS卫星第九频道模拟Hi-Vision放送于2007年9月30日正式停播。至此,这个世界上开播最早持续时间最长画质也最好的MUSE制模拟 相似文献
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1背景介绍常见的无线电作弊器材从实现方式上可分为模拟语音类设备和数传看字类设备,后者通常是利用现有各种无线数传芯片来实现,比如EZRadio PRO的Si4432、AMICCOM的A7139、NORDIC的n RF40x、n RF90x系列等等。由于数传类无线电作弊器材传输效率高、信号持续时间短,与需要长时间发射的模拟语音设备相比,难以被无线电监管部门的监测测向手段所定位,因此,随着各地无线电管 相似文献
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Zhen Gu Yi-Lun Ying Bing-Yong Yan Hui-Feng Wang Pin-Gang He Yi-Tao Long 《中国化学快报》2014,25(7):1029-1032
Nanopore technique plays an important role in single molecule detection, which illuminates the properties of an individual molecule by analyzing the blockage durations and currents. However, the traditional exponential function is lack of efficiency to describe the distributions of blockage durations in nanopore experiments. Herein, we introduced an exponentially modified Gaussian (EMG) function to fit the duration histograms of both simulated events and experimental events. In comparison with the traditional exponential function, our results demonstrated that the EMG provides a better fit while covers the entire range of the distributions. In particular, the fitted parameters of EMG could be directly used to discriminate the sequence length of the oligonucleotides at single molecule level. 相似文献
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通过某牵引拖挂装车式陆用火控雷达跑车试验,进行振动数据采集分析和处理得到垂直,纵向,横向三个方向的振动和加速度功率谱密度曲线,将之与美军标MIL.STD.810E与国军标GJB150中振动试验和加速度谱密度曲线进行比较,和工程实践对照,拓展形成一组更加符合实际条件且在实验室再现的功率谱密度曲线,并推荐将这组曲线作为陆用拖车载设备的振动试验条件。 相似文献
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The interference of high-order harmonics generated by two successive gas jets within a single laser pulse is discussed by a modeling with the inclusion of macroscopic propagation of the fundamental and harmonic fields in an ionizing medium. Based on the interference, we show that one can extract the laser Rayleigh range from the interference of harmonics and the accuracy of retrieve is independent of carrier-envelope phase while dependent on the pulse duration. Moreover~ we demonstrate that it is possible to optimize the single or range of harmonics with a high ratio relative to the adjacent orders by changing the separation of two gas jets, which is unavailable by using a single gas jet and linear polarized laser pulse. 相似文献
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In this article, we investigate Programming Evaluation and Review Technique networks with independently and generally distributed activity durations. For any path in this network, we select all the activities related to this path such that the completion time of the sub-network (only consisting of all the related activities) is equal to the completion time of this path. We use the elapsed time as the supplementary variables and model this sub-network as a Markov skeleton process, the state space is related to the subnetwork structure. Then use the backward equation to compute the distribution of the sub-network's completion time, which is an important rule in project management and scheduling. 相似文献
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Energy spectrum of multi-radiation of X-rays in a low energy Mather-type plasma focus device
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The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device (operated with argon gas). The analysis is based on the effect of anomalous resistances. To study the energy spectrum, a four-channel diode X-ray spectrometer was used along with a special set of filters. The filters were suitable for detection of medium range X-rays as well as hard X-rays with energy exceeding 30 keV. The results indicate that the anomalous resistivity effect during the post pinch phase may cause multi-radiation of X-rays with a total duration of 300 ± 50 ns. The significant contribution of Cu-Kα was due to the medium range X-rays, nonetheless, hard X-rays with energies greater than 15 keV also participate in the process. The total emitted X-ray energy in the forms of Cu-K and Cu-K/3 was around 0.14 ± 0.02 (J/Sr) and 0.04 ±0.01 (J/Sr), respectively. The total energy of the emitted hard X-ray (〉 15 keV) was around 0.12± 0.02 (J/Sr). 相似文献