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981.
982.
In the malware analysis, it is a common method to monitor malware dynamically in a virtual environment. However, with so many branches of executable pathes, path explosion problem will probably occur, leaving some executable pathes uncovered, and hence harming the comprehensiveness of analysis. To solve this problem, we propose a malware analysis method based on symbolic execution tree. This method introduces sinknode and solves the execution of malicious code path by constructing the symbolic execution tree, so improves the analysis of comprehensive. Experiments to analyze the samples of malware show that the method can enhance the efficiency of the analysis with lower time complexity. 相似文献
983.
Vehicle ignition system is the main electromagnetic interference source. Electromagnetic radiation produced by ignition system will produce the interference to electromagnetic environment around. It is necessary to study the electromagnetic interference (EMI) principle, noise paths and suppression method. We analyze the electromagnetic interference principle of ignition system, and harness trouble-shooting related to electromagnetic interference is also tested. Results show that the spark discharge between spark plug electrodes is the main interference source in ignition system. Then, the paths of conducted interference and the reason of radiated emission are discussed in detail. Finally, two kinds of power supply cord EMI filters are designed and implemented on the basis of analysis results. Experimental results indicate that the filter can reduce the noise of power-wire in broadband range. Simultaneously, the radiation emission performance from power wire is also reduced observably. The proposed mixing filter has been demonstrated in this paper to perform satisfactorily with excellent effectiveness in suppression of conducted EMI from 10 MHz to 110 MHz, and the object car can also pass the EMC standard tests. 相似文献
984.
Fast modeling of the motor broadband equivalent circuit model 总被引:2,自引:0,他引:2
This paper proposes a modeling method of the motor broadband equivalent circuit model. The impedance amplitude-frequency characteristics of the motor terminal through measuring are obtained. The impedance amplitude-frequency characteristics are devided into several regions based on its first resonant point information,and the motor broadband circuit topology is developed with each region equaling a resonance unit. The RLC parameters of resonance unit are extracted through frequency and corresponding impedance of the any non-resonant and resonant point in each unit. This proposed method is used to build DC and AC motor broadband equivalent circuit model. Their impedance amplitude-frequency characteristics are simulated by the Saber software. The measurement results and the simulation result of references are compared. The DC motor simulation results coincide with the measurement results in 0.1~50 MHz,and the AC motor is in 0.1~40 MHz. The results show that the motor broadband circuit model is reliable and feasible. 相似文献
985.
随着人们对环境与食品安全的关注,有机产品的消费需求应运而生,有机烟草生产也开始在国内出现.为了探索有机烤烟种植方式的可行性,作者于2008年至2010年在大理州宾川县拉乌乡开展了有机烟叶生产试验示范,从种植技术、烤烟农艺性状、病害发生、常规化学成分、产量效益等,综合分析了有机种植与常规种植的差异,为有机烟叶规模化生产提供指导.结果表明,种植密度对烟叶中后期病害的发生影响较大,有机种植应适当降低种植密度;施肥量不仅影响烤烟生长、产量与品质,而且与烟叶中后期病害程度直接相关;有机种植的初烤烟叶较常规种植的产量平均减少18.7%,因此发展有机烤烟种植,主管部门应出台相应的补贴政策. 相似文献
986.
987.
基于AHP-模糊综合评价法的沙棘涵养水源功能评价 总被引:1,自引:0,他引:1
采用专家咨询、现场调查和文献查阅相结合的方法并参考森林生态服务功能评估规范,构建了沙棘涵养水源功能评价的指标体系,并参照其他植被涵养水源功能参数及经验公式计算等对指标体系进行等级划分。将层次分析法和模糊综合评价模型相结合,对晋、陕、蒙砒砂岩区沙棘涵养水源功能进行评价。结果表明,沙棘在砒砂岩区涵养水源方面发挥了良好的生态服务功能,其大面积种植对于改善砒砂岩区的生态环境起到了显著作用,具有良好的开发潜质和前景。研究显示,该评价方法可操作性较好,结果客观可信,具有一定的推广价值和应用性。 相似文献
988.
本文发表贵阳市种子植物新记录21属,共27种(包括变种).凭证标本存于贵阳市林业种苗站.
十、 忍冬科Caprifoliaceae
(一) 双盾木属Dipelta Maxim. 相似文献
989.
990.