目前,基于正交频分复用(Orthorgonal Frequency Division Multiplexing,OFDM)的多载波相位编码雷达的转发欺骗干扰主要通过调制转发和直接复制转发来实现。传统干扰形式简单,干扰信号滞后时延长、规律性强、可预测性高。本文将间歇采样...目前,基于正交频分复用(Orthorgonal Frequency Division Multiplexing,OFDM)的多载波相位编码雷达的转发欺骗干扰主要通过调制转发和直接复制转发来实现。传统干扰形式简单,干扰信号滞后时延长、规律性强、可预测性高。本文将间歇采样转发干扰思想引入到多载波相位编码体制雷达中,对经过伪噪声(Pseudo-Noise,PN)序列调制、P4码及混沌二相码(chaotic binary-phase code,CBPC)的OFDM雷达信号进行干扰效果分析;并在不同的干扰转发方式下,得到了各干扰参数与干扰效果间的映射关系,实现了对多载波相位编码雷达的幅度、数量、空间分布可控的逼真假目标干扰。结果表明:间歇采样直接转发干扰对信号编码方式的变化不敏感,但能形成单一假目标干扰;间歇采样重复转发干扰可形成逼真假目标串,且在采样占空比较小时,能对雷达系统形成近似压制式的干扰效果。展开更多
Under the inflammable or explosive environment, the direct measurement methods by opening up the explo- sion-proof shell of electrical installations were not adopted. So, it＇s impossible to have a quantitative analys...Under the inflammable or explosive environment, the direct measurement methods by opening up the explo- sion-proof shell of electrical installations were not adopted. So, it＇s impossible to have a quantitative analysis on the limit of conducted disturbance for electrical fast transient burst （EFT/B） in such dangerous environments. Transient conducted coupling model, which using EFT/B as its excitation source, can be built based on circuit and electromagnetic field theory. Furthermore, numerical analysis was performed. The results indicate that the capacitive coupling voltage is the same polarity as EFT/B, and is the main disturbance form of conducted coupling in mines. The inductive coupling voltage is reversed polarity with the ca- pacitive coupling voltage, and both peaks appear only in the rising time of EFT/B, which increase with the rising of load resistance. Moreover, the cable coupling voltage on the side of disturbance source is higher than the one on the other side in tunnel. To reduce the common resistance can suppress the resistive coupling disturbance.展开更多
Born of the America of 1960s, performance art comes along as a celebration of presentation rather than re-presentation, as a display form of art, and an art form that does not admit of duplication. This paper presents...Born of the America of 1960s, performance art comes along as a celebration of presentation rather than re-presentation, as a display form of art, and an art form that does not admit of duplication. This paper presents a reading of the seductive power of performance art as rooted in our theatrical nature. I will address performance art as an emancipated form of the theatrical, where by ＂theatrical＂ I mean a specific mode of presentation and a specific mode of perception： the mode of presentation of the self to the social and the mode of perception of the self through the social. Performance art, I will argue, is hardly an anomaly of our time. Rather, its source of disturbance and fascination lies in the natural, though excessive manifestation of our theatrical nature. By its appeal to the shocking, the perilous, or the mundane even, this form of art confirms what Paul Woodruff has addressed as ＂the necessity of watching and being watched.＂ Performance art shows us the danger of self-presentation, the recognition of the other gaze as the self＇s greatest need and greatest fear. It needs no words. Mere action is more seductive than speech and does not accept speech in return. Once it has been performed, it is no longer. In Nietzsche＇s words, it celebrates the fleeting moment＇s ＂greatest weight.＂ As Samuel Beckett used to tell his actors, performance artists seem to tell their spectators： ＂Go on failing. Go on. Only next time, try to fail better.＂展开更多
纽约哥伦比亚大学Uriel Weinreich教授的《接触中的语言:现象分析与难题化解》(Languagesin Contact:Findings and Problems)一书最早由荷兰海牙的Mouton公司在1953年出版,是"纽约语言学圆桌会书系"的第一本,1963年修订重印...纽约哥伦比亚大学Uriel Weinreich教授的《接触中的语言:现象分析与难题化解》(Languagesin Contact:Findings and Problems)一书最早由荷兰海牙的Mouton公司在1953年出版,是"纽约语言学圆桌会书系"的第一本,1963年修订重印时又增加了Andre Martinet教授的序。全书共有五章,148页。本文先介绍各章内容,再作一个短评。展开更多
基金Supported by the National Natural Science Foundation of China （50674093） the Project of Fujian Provincial Education Department （JA11098）
文摘Under the inflammable or explosive environment, the direct measurement methods by opening up the explo- sion-proof shell of electrical installations were not adopted. So, it＇s impossible to have a quantitative analysis on the limit of conducted disturbance for electrical fast transient burst （EFT/B） in such dangerous environments. Transient conducted coupling model, which using EFT/B as its excitation source, can be built based on circuit and electromagnetic field theory. Furthermore, numerical analysis was performed. The results indicate that the capacitive coupling voltage is the same polarity as EFT/B, and is the main disturbance form of conducted coupling in mines. The inductive coupling voltage is reversed polarity with the ca- pacitive coupling voltage, and both peaks appear only in the rising time of EFT/B, which increase with the rising of load resistance. Moreover, the cable coupling voltage on the side of disturbance source is higher than the one on the other side in tunnel. To reduce the common resistance can suppress the resistive coupling disturbance.
文摘Born of the America of 1960s, performance art comes along as a celebration of presentation rather than re-presentation, as a display form of art, and an art form that does not admit of duplication. This paper presents a reading of the seductive power of performance art as rooted in our theatrical nature. I will address performance art as an emancipated form of the theatrical, where by ＂theatrical＂ I mean a specific mode of presentation and a specific mode of perception： the mode of presentation of the self to the social and the mode of perception of the self through the social. Performance art, I will argue, is hardly an anomaly of our time. Rather, its source of disturbance and fascination lies in the natural, though excessive manifestation of our theatrical nature. By its appeal to the shocking, the perilous, or the mundane even, this form of art confirms what Paul Woodruff has addressed as ＂the necessity of watching and being watched.＂ Performance art shows us the danger of self-presentation, the recognition of the other gaze as the self＇s greatest need and greatest fear. It needs no words. Mere action is more seductive than speech and does not accept speech in return. Once it has been performed, it is no longer. In Nietzsche＇s words, it celebrates the fleeting moment＇s ＂greatest weight.＂ As Samuel Beckett used to tell his actors, performance artists seem to tell their spectators： ＂Go on failing. Go on. Only next time, try to fail better.＂
