线性电路的两个性质及其应用

本文提出了两个线性电路的性质,一个是利用变换受控源控制变量的方法,将受控源的输出特性改造成支路特性的形式,这样,受控源可用一条含源支路等效代替,另一个是支路移位的概念,按照这一概念,在电路中可以断开任一支路,或者,将两个回路间的公共支路一劈为二,而不改变电路的工作状态。掌握了上述的电路性质为分析电路增添了可供选择的方法。     

亚谐波注锁振荡器的分析

评估了各种注锁振荡器的分析方法,提出了亚谐波注锁振荡器的谐波平衡法。     

关于异步时序电路中时钟条件的讨论

本文通过对触发器特性方程的进一步研究将异步时序电路中触发器的时钟条件用布尔函数出来，直接反映在状态方程中，从而可以直接确定触发器的状态，这样，对异步时序电路的分析更直观，方便。     

组合电路最优Hopfield模型的判定算法

组合电路的故障检测问题是一个ＮＰ完全问题。根据组合电路的Ｈｏｐｆｉｅｌｄ神经网络模型，通过相容状态建立的齐次线性方程组的基础解系和感知机，提出了组合电路最优Ｈｏｐｆｉｅｌｄ模型存在性的实用判定算法，并给出了计算实例。     

Reaching Beyond the Net: Political Circuits and Participation in Toronto's G20 Protests

Using a survey of 359 participants in the 2010 protests against the G20 in Toronto, this paper examines the effects and effectiveness of the different communication media in informing diverse participants about the protest. It finds that the communication networks that surrounded the G20 summit protest in Toronto in 2010 were dense and interconnected. Drawing on Tilly's ‘political circuits’, the survey shows that activists at the core of these networks used a combination of online and offline modes of communication, while those outside of that core were reliant on fewer channels of information about the protests. These included people of colour, people who are not part of student networks, less educated people and people less involved in existing social movements. Using logistic regression models, we demonstrate that the digital divide may be less important than the structure and means of communication that make up the political circuits of a movement. Based on these models, we argue that communication modes such as social networking sites and the mainstream media may be important tools for bridging the gap between core and peripheral participants.     

采集系统报警电路

根据自动控制系统的要求，用一片555时基电路设计了一种报警电路。介绍了设计方法并对电路工作原理作了分析，同时给出软件的程序流程图。     

基于布尔差分的数字逻辑电路故障诊断

讨论了数字系统的故障分析的内涵,阐述了故障的可测性定理,并以组合逻辑电路为例,介绍如何利用布尔差分法求解其全部测试码,给出了多重故障测试码的公式,说明了布尔差分法数字系统故障诊断的局限性。     

Cultural Circuits of Climate Change in U.K. Broadsheet Newspapers, 1985–2003

This article argues for a cultural perspective to be brought to bear on studies of climate change risk perception. Developing the "circuit of culture" model, the article maintains that the producers and consumers of media texts are jointly engaged in dynamic, meaning-making activities that are context-specific and that change over time. A critical discourse analysis of climate change based on a database of newspaper reports from three U.K. broadsheet papers over the period 1985-2003 is presented. This empirical study identifies three distinct circuits of climate change-1985-1990, 1991-1996, 1997-2003-which are characterized by different framings of risks associated with climate change. The article concludes that there is evidence of social learning as actors build on their experiences in relation to climate change science and policy making. Two important factors in shaping the U.K.'s broadsheet newspapers' discourse on "dangerous" climate change emerge as the agency of top political figures and the dominant ideological standpoints in different newspapers.     

有模糊时间窗的车辆调度组合干扰管理研究

研究带有模糊时间窗的车辆调度组合干扰管理模型及其混合遗传算法.采用时间窗模糊化处理方法,定义客户满意度函数,根据干扰管理思想对车辆调度中组合性干扰事件进行分析,从配送路径、配送成本和客户满意度三个方面进行干扰辨识与度量,建立基于模糊时间窗的车辆调度组合干扰管理模型;构造模型求解的混合遗传算法,将最佳客户插入规则与遗传算法结合,同时在算法中嵌入模糊优化程序以处理问题的模糊特征;进行数值实验,实验结果验证了模型与算法的有效性.     

改善DDS输出LFM信号谱质的方法

分析了直接数字合成的相位截断杂散、幅度量化误差杂散和DAC非线性杂散的分布规律。根据这些噪声分布特点,提出了一种利用设计合理的外围电路和选择合理的控制字的方法,提高了直接数字合成技术产生的线性调频信号的频谱纯度,并用直接数字合成芯片AD9854设计了线性调频信号合成器。实验结果表明,用该方法产生的线性调频信号在带宽达30MHz时,无杂散动态范围达到了62dB,改善了近10dB。