共查询到19条相似文献,搜索用时 328 毫秒
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分析了直冷电冰箱单路、双路、多路循环及双机、双级制冷循环,进行了系统匹配性、市场占有率、成本及其COP值比较。针对双路循环存在的频繁开停机现象,提出了完善控制方式及采用双稳态电磁阀的变温技术。变温室蒸发器与冷冻室蒸发器串联,其前串联双稳态电磁阀2,并在变温室蒸发器上并联双稳态电磁阀1,据变温室温度设定改变双稳态电磁阀通断实现两个循环支路交替制冷。冷藏室温度控制压缩机启停,变温室温度仅控制双稳态电磁阀通断,实现切换制冷剂流向目的。应用该循环方式及相关措施研制的BCD-188CH直冷电冰箱最大负荷日耗电0.38度,变温情况下耗电在0.35度以下,最低达0.31度。 相似文献
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针对反作用控制系统(Reaction Control System,RCS)快速响应电磁阀频繁工作的特性,从节能控制的角度出发,设计了一种基于脉宽调制(Pulse Width Modulation,PWM)技术的电磁阀控制驱动方案。建立电磁阀电路模型,通过仿真计算,确定了PWM频率及占空比对电磁阀线圈电流的影响,为电磁阀驱动电路参数的选取提供依据。搭建RCS电磁阀电流测试平台,设定PWM占空比为50%,试验结果表明:流经电磁阀的保持电流仅为开启电流的1/2,既能保证电磁阀正常开启,又避免了电磁阀处于高负载工作状态,有效地验证了该节能控制方案的正确性。 相似文献
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描述了合肥同步辐射光源二期工程中,电子储存环升级的闭轨测量系统及其在设备研制中的应用。介绍了性能稳定可靠的Bergoz束流位置监测电子学信号处理器。升级后的闭轨测量系统中处理电子学电路的束流位置分辨率可达1μm,系统误差小于10μm。整个测试系统的分辨率小于3μm。利用该高精度闭轨测量系统和基于束流准直系统完成了束流准直四极铁磁中心的测量,并和控制系统完成了储存环全环闭轨反馈校正试验。一个完整的束流位置监测系统已投入了在线运行,保障了为用户提供高稳定高品质的光源。 相似文献
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《中国光学与应用光学文摘》2005,(2)
O437 2005021105 声光双稳态系统的周期驱动混沌=Acousto-optic bistable system chaos anti-control via periodic signal drive[刊,中]/ 张涛(中国科技大学物理系.安徽,合肥(230026)),冯忠耀 …//光子学报.-2004,33(5).-557-559 利用外周期信号对处于周期态的声光双稳态系统进 行驱动,在合适的驱动强度和频率下,系统可能从周期态 转换为李雅普诺夫指数意义下的混沌态。提出了这一混 相似文献
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为了分析方波驱动长螺线管内磁场畸变机理,利用麦克斯韦方程研究了螺线管内外的磁场分布情况。首先,利用麦克斯韦方程,分别建立了正弦波驱动螺线管内外电场、磁场模型,并结合安培环路定律和电磁感应定律选取了合适的边界条件,得到了正弦波驱动长螺线管的磁场分布;其次,通过傅里叶变换将方波信号变换为多个正弦信号叠加的形式,从而得到了方波驱动长螺线管磁场分布;最后,通过仿真试验重点分析了方波驱动信号频率对磁场的影响,并得出结论:方波驱动长螺线管磁场波形会失真、畸变,驱动信号频率较低、距离螺线管轴线距离较近处,磁场的方波特性较好。 相似文献
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The coordinate of a white noise driven harmonic oscillator is used as a stochastic source term in bistable dynamics. This new kind of Gaussian colored noise gives rise to resonance phenomena due to a peak in the spectrum. We investigate its effect on linear and bistable systems. We derive a Markovian approximation for driven bistable oscillators and overdamped systems. In the resonance region computer simulations were carried out using an extension of Fox' algorithm procedure for colored noise. We find an increase of the transition rates in bistable systems as compared with the case of bistable systems driven by white and exponentially correlated noise. 相似文献
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Instead of a continuous system driven by Gaussian white noise, logical stochastic resonance will be investigated in a nonlinear bistable system with two thresholds driven by dichotomous noise, which shows a phenomenon different from Gaussian white noise. We can realize two parallel logical operations by simply adjusting the values of these two thresholds. Besides, to quantify the reliability of obtaining the correct logic output, we numerically calculate the success probability, and effects of dichotomous noise on the success probability are observed, these observations show that the reliability of realizing logical operation in the bistable system can be improved through optimizing parameters of dichotomous noise. 相似文献
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为了实现远程控制电磁阀及监测输水管道水压,提高农业灌溉效率;采用STM32微控制器及Android嵌入式系统,开发出一种对电磁阀进行控制及水压监测系统。微控制器通过串口连接GPRS模块,从而接收命令控制电磁阀和发送水压数据;Android手机客户端实现阀门控制界面和水压数据显示功能;云服务器负责连接GPRS模块和手机客户端,并且管理底层设备与用户信息。该系统已运用在某智能节水灌溉公司的实验大棚基地中,实验结果表明,系统能实时进行远程控制及监测,并能确保输水系统正常运行。该系统能够推动农业现代化的发展,减少人力成本,提高生产效率。 相似文献
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在注气持续时间短、注入气体质量大的快速电磁阀测量中,采用高频响应压力传感器在电磁阀出口测量了气体的动态压力,通过真空室注气前后的压强差测量了注入气体的质量。研究表明,驱动电流、位移限定以及背景气压对气体注入特性有显著影响。当阀片受到的电磁力远大于背景气压造成的阻力时,增大驱动电流和增大背景气压都会加速流道口气体流动,提高气体注入量;电磁阀最高流速超过当地声速,流道应该设计成扩张式,且流道的长度要求尽可能短;电磁阀的注气持续时间主要由阀片的运动时间以及阀片关闭后气体在流道内扩散速率决定的。 相似文献
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Masoller C 《Physical review letters》2003,90(2):020601
I study bistable time-delayed feedback systems driven by noise. Based on a two-state model with transition rates depending on the earlier state of the system I calculate analytically the residence-time distribution function. I show that the distribution function has a detailed structure, reflective of the effect of the feedback. By using an adequate indicator I give evidence of resonant behavior in dependence on the noise level. I also predict that this feedback-induced effect might be observed in two well-known optical bistable systems. 相似文献
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In this paper we propose a new scheme to achieve chaos control and synchronization in Bragg acousto-optic bistable systems. In the scheme, we use the output of one system to drive two identical chaotic systems. Using the maximal conditional Lyapunov exponent (MCLE) as the criterion, we analyze the conditions for realizing chaos synchronization. Numerical calculation shows that the two identical systems in chaos with negative MCLEs and driven by a chaotic system can go into chaotic synchronization whether or not they were in chaos initially. The two systems can go into different periodic states from chaos following an inverse period-doubling bifurcation route as well when driven by a periodic system. 相似文献
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The magnetic resonance line of conduction electrons in solids may exhibit bistable hysteresis if several conditions are fulfilled. Its mechanism is presented and the manifestation of bistability in the ESR of conduction electrons in single crystal and polycrystalline samples is discussed. The characteristics of the dynamics of the bistability show that bistable resonance can be assimilated to one-dimensional overdamped motion of the spin system in the nuclear field space, driven by a bistable potential. It is shown for the first time that noise acting on this bistable resonance can create order, by the phenomenon of stochastic resonance. 相似文献