共查询到19条相似文献,搜索用时 429 毫秒
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为用集成运算放大器LM324制作的微电流放大器电路图.集成运算放大器是一种高电压增益、高输入电阻和低输出电阻的多级直接耦合放大电路,它不仅能够放大交流信号,而且能够放大缓慢变化的信号或直流信号.图1中ICI(1/4LM324)为信号放大部分,采用差动输入,外部输出调零. 相似文献
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塑料闪烁体阵列探测器(PSD,简称塑闪阵列探测器)的输出信号经过前置放大器和滤波成形电路后输出准高斯波形,利用峰值保持电路可对准高斯波形信号的峰值进行采样和保持,以便后续的电子学系统对其进行进一步的分析。本工作采用180 nm CMOS工艺设计并实现了一款峰值保持电路ASIC芯片,每通道主要由跨导放大器(OTA)、电流镜和充电电容三部分电路组成。实验室电子学功能和性能测试结果表明:峰值保持电路功能良好;输入动态范围为33~940 mV,非线性误差优于0.8%,下垂速率好于8.6 μV/μs,峰值探测延迟时间小于35 ns,芯片单通道静态功耗为825 μW,达到设计要求。 相似文献
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韦尔代常数(Verdet)是决定光纤电流传感器(FOCT)灵敏度的重要因素之一。根据萨格纳克(Sagnac)干涉原理计算得到校准信号,并测量FOCT的实际输出信号,通过比较这两组信号建立目标函数,基于单纯形算法进行参数优化,从而得到石英光纤的韦尔代常数。实验结果与经典模型计算结果基本吻合。FOCT的输出信号经过测量电路会引入相位差;另外受到调制器和外界环境的影响,干涉回路的工作点会产生漂移,导致输出信号不对称而产生直流量。考虑到以上因素,提出的这种方法还能同时测量出电路的相位差、干涉回路的工作点以及反映非线性畸变的直流量。 相似文献
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为了在基于脉冲式中红外量子级联激光器的气体检测系统中,精确提取窄脉冲传感信号的幅度,设计并实现了一种微秒级窄脉冲锁相放大器.根据微秒级窄脉冲的特点,窄脉冲信号经过窄带通滤波电路,得到基频正弦波信号,再经过主放大、移相、相敏检波电路,得到与脉冲幅值有关的直流信号.利用信号发生器产生的幅度、频率、相位可调的窄脉冲待测信号,对锁相放大器进行功能验证实验.结果表明,锁相放大器输出直流信号与输入信号的幅度呈良好的线性关系,线性拟合度约为98.043%;信号幅值的相对测量误差不超过3%;在1 h的测试时间内,信号波动范围在1‰以内.利用配备的不同浓度的一氧化碳样品及研制的锁相放大器,开展了一氧化碳气体检测实验.在0~180 ppm范围内,随着一氧化碳浓度的增加,锁相放大器的输出电压值与一氧化碳浓度呈现良好的e指数关系.根据A11an方差预测的系统检测下限为0.4123ppm.与商用锁相放大器相比,该放大器具有体积小、成本低、易于集成等特点,在基于脉冲式中红外量子级联激光器的气体检测中具有较好的应用前景. 相似文献
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研究和建议了一种用于产生亚12fs脉冲的基于脉冲波前匹配的LBO超宽带光学参量啁啾脉冲放大器。实验结果表明LBO超宽带光学参量啁啾脉冲放大器可以输出大于60nm(FWHM)的增益光谱带宽,为了利用这种放大器产生转换限制的脉冲输出,给出了一种将超宽带光学参量啁啾脉冲放大器与脉冲波前匹配相结合的方法,这种方法等价于信号光脉冲波前无斜置的放大,克服了超宽带参量啁啾脉冲放大器中由于信号光的脉冲波前斜置而导致很难获得最短压缩脉冲输出的缺陷,从而允许产生转换限制的亚12fs脉冲。 相似文献
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以七芯光纤激光器为例,提出一种提高多芯光纤激光器总输出光功率中共相位模式所占比例的方法,即把多芯光纤激光器作为种子光源,输出信号光再经过多芯光纤放大器进行放大。基于速率方程组对激光器和放大器中的模式竞争进行了数值分析。计算表明:激光器输出端与放大器输入端之间距离存在一个最佳值,以使得放大器输出信号中低阶模式功率占总输出功率的比例最低,可以下降到小于1%。研究表明:级联放大系统可以有效增强共相位模式同时抑制低阶模式,比传统的塔耳博特腔激光器具有更好的光束质量。 相似文献
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Injection of high-Z impurities into plasma has been proved
to be able to reduce the localized thermal load and mechanical forces on
the in-vessel components and the vacuum vessel, caused by
disruptions in Tokamaks. An advanced prediction and mitigation
system of disruption is implemented in HL-2A to safely shut down
plasmas by using the laser ablation of high-Z impurities with a
perturbation real-time measuring and processing system. The
injection is usually triggered by the amplitude and frequency of
the MHD perturbation field which is detected with a Mirnov coil and leads
to the onset of a mitigated disruption within a few milliseconds. It
could be a simple and potential approach to significantly reducing the
plasma thermal energy and magnetic energy before a disruption,
thereby achieving safe plasma termination. The plasma
response to impurity injection, a mechanism for improving plasma
thermal and current quench in major disruptions, the design of
the disruption prediction warner, and an evaluation of the mitigation success rate
are discussed in the present paper. 相似文献
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Short-duration electrical pulses play important roles in ultrafast time-domain metrology: they are used to sample rapidly varying signals or as probe signals in ranging radars, time-domain reflectometry and in communication. In this work, we design a nonlinear transmission, which is loaded with resonant tunneling diode to be suitable for microwave A/D conversion. A resonant tunneling diode (RTD) has a negative differential resistance that means when the voltage increases the current decreases. The equivalent circuit of monostable line is given. The simulation is performed by using OrCad program. Results show that a spike is produced and after a charging time constant, another switching occurs. Hence – similar to a relaxation oscillator – the spiking period is determined by the amplitude and frequency of the input current. The transmission line itself ensures the generation and propagation of identical spikes, such as solitons formed after few diodes. 相似文献
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收缩螺旋涡线诱导速度的快速收敛法 总被引:1,自引:0,他引:1
给出了一种计算收缩涡线(桨尖涡和内部涡线)诱导速度所有组元的快速收敛方法,该方法是由Rand和Chiu的方法(计算螺旋涡线诱导速度快速收敛法)发展而来的,它以寻求上下界截断积分解析表达式为基础。其优点是能计算尾迹中任意一点的诱导速度,并且考虑了尾迹收缩。该方法不仅避免了离散涡线引起的截断误差。而且减小了沿有限方位角所产生的误差。 相似文献
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J. J. Savović M. M. Kuzmanović M. S. Pavlović M. Stoiljković D. P. Ranković M. Marinković 《光谱学快报》2013,46(4):166-173
Radial distributions of plasma parameters, temperature, and electron number density, together with radial distribution of analyte absorption and emission, were investigated in order to obtain insight into the radial symmetry of low-current (≤ 10 A), atmospheric pressure, argon stabilized arc with tangential introduction of the aerosol. For plasma diagnostics, several methods were used: measurements of Hβ line profile, absolute intensity measurements of the argon 430.01-nm line, and of the spectrally adjacent continuum and power interruption technique. It was found that the inevitable asymmetry in aerosol introduction has negligible influence on basic plasma parameters but influences considerably the spatial distribution of the analyte particle spectral absorption and emission. 相似文献