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三相交流调压模块在线性调压式恒流源中的应用 被引量:1
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作者 曹科峰 邓建军 +4 位作者 赵娟 朱利君 杨磊 叶超 张纪昌 《电源技术应用》 2003年第6期43-44,共2页
某大功率恒流源,其负载为0.05~0.1Ω的感性或电阻性,输出电流200~500A连续可调,并对稳定度、准确度、重复性、纹波等技术指标均有较高要求由于采用了三相交流调压模块,使调整管的管压降被控制在5~10V范围内,从而使调整管的数量成倍... 某大功率恒流源,其负载为0.05~0.1Ω的感性或电阻性,输出电流200~500A连续可调,并对稳定度、准确度、重复性、纹波等技术指标均有较高要求由于采用了三相交流调压模块,使调整管的管压降被控制在5~10V范围内,从而使调整管的数量成倍地减少,既简化了散热措施,优化了结构布局,而且达到了提高技术性能指标。 展开更多
关键词 线性调压式恒流源 三相交流模块 恒流源主电路 电阻性 可靠性
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带线性调压器的开关电源芯片MC33998
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作者 曾洁 《国外电子元器件》 2004年第9期67-68,共2页
关键词 线性调压 开关电源 MC33998 MOTOROLA公司
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线性调压器功耗减少电路
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作者 路凯 《电子与仪表》 1994年第1期46-47,共2页
关键词 线性调压 电路
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一种井下仪器用可调直流电源装置设计
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作者 李红伟 王国荣 +1 位作者 靳涛 黄莉婷 《电气应用》 北大核心 2010年第2期64-66,74,共4页
介绍了一种井下仪器用可调直流电源装置的设计方法,电源采用线性调压稳压电路,给出了系统结构图和主要部分的电路原理图,以及软件设计方案。所设计电源电压可调范围宽,稳压精度高;纹波干扰小,满足设计要求,经过实验室和现场试验,能可靠... 介绍了一种井下仪器用可调直流电源装置的设计方法,电源采用线性调压稳压电路,给出了系统结构图和主要部分的电路原理图,以及软件设计方案。所设计电源电压可调范围宽,稳压精度高;纹波干扰小,满足设计要求,经过实验室和现场试验,能可靠保证井下仪器正常稳定工作。 展开更多
关键词 直流电源 线性调压 数字滤波 PIC单片机
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电力电子技术在电源设计中的应用:线性电压调节器
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作者 邓隐北 孙永德(编译) 《磁性元件与电源》 2020年第8期146-150,156,共6页
1简单的线性调压器藉助于简单的线性调压器以提供稳定的电压源,对这一问题的最明显解决方法进行探讨。这可以按照分立(discrete)技术(即采用分立元件构成的方式)解决,也可由专用的集成电路(IC)调压器,或这二者的结合来解决。
关键词 电力电子技术 节器 分立元件 线性调压
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一种谐振开关电容变换器的再分析与改进 被引量:9
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作者 夏守行 张佐理 《电工技术学报》 EI CSCD 北大核心 2013年第4期126-132,共7页
针对一种常见的谐振降压式开关电容直流变换器,使用近似取值方法进行再分析,简化了以往理论分析结果,并指出该电路存在的一些问题。由此提出了一种恒流充电谐振放电工作方式的新式改进电路,在该电路工作的任意时间内,导通的开关器件总... 针对一种常见的谐振降压式开关电容直流变换器,使用近似取值方法进行再分析,简化了以往理论分析结果,并指出该电路存在的一些问题。由此提出了一种恒流充电谐振放电工作方式的新式改进电路,在该电路工作的任意时间内,导通的开关器件总处于有电流状态,避免了开关器件的导通电流在时间上分布过于集中,因而降低了电路峰值电流,提高了变换效率。通过推导,得出新改进电路的输出电压、变换效率及谐振平均电流的数学表达式,最后进行了实验验证。理论与实验均表明,新改进电路能在较大范围内进行近似线性的调频方式调压,为高效率谐振式开关电容直流变换器的设计提供了理论依据。 展开更多
关键词 谐振开关电容变换器 近似取值 恒流 线性调压 变换效率 平均电流
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异步电动机起动及节能智能控制技术综述 被引量:8
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作者 刘建业 安曙明 +2 位作者 付占稳 梁国壮 甄然 《电工技术杂志》 2004年第3期7-10,共4页
关键词 异步电动机 软起动器 节能 智能控制 软起动控制方式 线性调压控制
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Research on the imaging of concrete defect based on the pulse compression technique 被引量:3
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作者 李长征 张碧星 +1 位作者 师芳芳 谢馥励 《Applied Geophysics》 SCIE CSCD 2013年第3期337-348,359,共13页
When the synthetic aperture focusing technology (SAFT) is used for the detection of the concrete, the signal-to-noise ratio (SNR) and detection depth are not satisfactory. Therefore, the application of SAFT is usu... When the synthetic aperture focusing technology (SAFT) is used for the detection of the concrete, the signal-to-noise ratio (SNR) and detection depth are not satisfactory. Therefore, the application of SAFT is usually limited. In this paper, we propose an improved SAFT technique for the detection of concrete based on the pulse compression technique used in the Radar domain. The proposed method first transmits a linear frequency modulation (LFM) signal, and then compresses the echo signal using the matched filtering method, after which a compressed signal with a narrower main lobe and higher SNR is obtained. With our improved SAFT, the compressed signals are manipulated in the imaging process and the image contrast is improved. Results show that the SNR is improved and the imaging resolution is guaranteed compared with the conventional short-pulse method. From theoretical and experimental results, we show that the proposed method can suppress noise and improve imaging contrast, and can also be used to detect multiple defects in concrete. 展开更多
关键词 Concrete defect LFM pulse compression SAFT SNR
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A Novel CMOS Voltage Reference Based on Threshold Voltage Difference Between p-Type and n-Type MOSFETs
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作者 孔明 郭健民 +1 位作者 张科 李文宏 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第10期1546-1550,共5页
A novel MOS-only voltage reference is presented,which is based on the threshold voltage difference between p-type and n-type MOSFETs. Its precision is improved by the cancellation of the process variation. The referen... A novel MOS-only voltage reference is presented,which is based on the threshold voltage difference between p-type and n-type MOSFETs. Its precision is improved by the cancellation of the process variation. The reference has been successfully implemented in a Chartered 0.35μm CMOS process. The occupied chip area is 0. 022mm^2. Measurements indicate that without trimming, the average output voltage error is 6mV at room temperature compared with the simulation result. The temperature coefficient is 180ppm/℃ in the worst case in the temperature range of 0 to 100℃ ,and the line regulation is ± 1.1%. The reference is applied in an adaptive power MOSFET driver. 展开更多
关键词 MOS-only voltage reference threshold voltage temperature coefficient line regulation
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Design of a Bandgap Reference with a Wide Supply Voltage Range 被引量:4
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作者 孙越明 赵梦恋 吴晓波 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第8期1529-1534,共6页
An on-chip voltage reference with a wide supply voltage range is required by some applications,especially that of power management (PM) controller chips applied to telecommunication, automotive, lighting equipment, ... An on-chip voltage reference with a wide supply voltage range is required by some applications,especially that of power management (PM) controller chips applied to telecommunication, automotive, lighting equipment, etc., when high power supply voltage is needed. Accordingly,a new bandgap reference with a wide supply voltage range is proposed. Due to the improved structure,it features a high power supply rejection ratio (PSRR) and high temperature stability. In addition, an auxiliary micro-power reference is introduced to support the sleep mode of the PM chip and reduce its standby power consumption. The auxiliary reference provides bias currents in normal mode and a 1.28V reference voltage in sleep mode to replace the main reference and save power. Simulation results show that the reference provides a reference volt- age of 1.27V,which has a 3.5mV drift over the temperature range from -20 to 120~C and 56t^V deviation over a supply voltage range from 3 to 40V. The PSRR is higher than 100dB for frequency below 10kHz. The circuit was completed in 1.5tzm BCD (Bipolar-CMOS-DMOS) technology. The experimental results show that all main expectations are achieved. 展开更多
关键词 wide supply voltage range bandgap reference line regulation sleep mode micro power
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NEW TYPE OF WINDOWS FOR DIGITAL PULSE COMPRESSION IN FREQUENCY DOMAIN FOR BROADBAND LFM SIGNALS 被引量:3
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作者 HuangWei FangKeying HuTe XiangJingcheng 《Journal of Electronics(China)》 2005年第2期149-152,共4页
A new type of window called combined window is designed to get higher Ratio of Mainlobe to Sidelobes (RMS) and lower Mainlobe Widening Factor (MWF). Simulation results prove that the new window can solve the contradic... A new type of window called combined window is designed to get higher Ratio of Mainlobe to Sidelobes (RMS) and lower Mainlobe Widening Factor (MWF). Simulation results prove that the new window can solve the contradiction between RMS and MWF better than classic windows. 展开更多
关键词 Linear frequency modulation WINDOWS Pulse compression
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Coordinated regulation of active and repressive histone methylations by a dual-specificity histone demethylase ceKDM7A from Caenorhabditis elegans 被引量:2
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作者 Hanqing Lin Yiqin Wang +11 位作者 Yanru Wang Feng Tian Pu Pu Yi Yu Hailei Mao Ying Yang Ping Wang Lulu Hu Yan Lin Yi Liu Yanhui Xu Charlie Degui Chen 《Cell Research》 SCIE CAS CSCD 2010年第8期899-907,共9页
H3K9me2 and H3K27me2 are important epigenetic marks associated with transcription repression, while H3K4me3 is associated with transcription activation. It has been shown that active and repressive histone methylation... H3K9me2 and H3K27me2 are important epigenetic marks associated with transcription repression, while H3K4me3 is associated with transcription activation. It has been shown that active and repressive histone methylations distribute in a mutually exclusive manner, but the underlying mechanism was poorly understood. Here we identified ceKDM7A, a PHD (plant homeodomain)- and JmjC domain-containing protein, as a histone demethylase specific for H3K9me2 and H3K27me2. We further demonstrated that the PHD domain of ceKDM7A bound H3K4me3 and H3K4me3 co-localized with ceKDM7A at the genome-wide level. Disruption of the PHD domain binding to H3K4me3 reduced the demethylase activity in vivo, and loss of ceKDM7A reduced the expression of its associated target genes. These results indicate that ceKDM7A is recruited to the promoter to demethylate H3K9me2 and H3K27me2 and activate gene expression through the binding of the PHD domain to H3K4me3. Thus, our study identifies a dual-specificity histone demethylase and provides novel insights into the regulation of histone methylation. 展开更多
关键词 KDM7A DEMETHYLASE H3K9me2 H3K27me2 PHD JMJC HISTONE methylation
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Peritrophin-like protein from Litopenaeus vannamei (LvPT) involved in white spot syndrome virus (WSSV) infection in digestive tract challenged with reverse gavage
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作者 谢世筠 李富花 +2 位作者 张晓军 张继泉 相建海 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第6期1524-1530,共7页
The peritrophic membrane plays an important role in the defense system of the arthropod gut. The digestive tract is considered one of the major tissues targeted by white spot syndrome virus (WSSV) in shrimp. In this... The peritrophic membrane plays an important role in the defense system of the arthropod gut. The digestive tract is considered one of the major tissues targeted by white spot syndrome virus (WSSV) in shrimp. In this study, the nucleotide sequence encoding peritrophin-like protein of Litopenaeus vannamei (LvPT) was amplified from a yeast two-hybrid library of L. vannamei. The epitope peptide of LvPT was predicted with the GenScript OptimumAntigenTM design tool. An anti-LvPT polyclonal antibody was produced and shown to specifically bind a band at -27 kDa, identified as LvPT. The LvPT protein was expressed and its concentration determined. LvPT dsRNA (4 pg per shrimp) was used to inhibit LvPT expression in shrimp, and a WSSV challenge experiment was then performed with reverse gavage. The pleopods, stomachs, and guts were collected from the shrimp at 0, 24, 48, and 72 h post-infection (hpi). Viral load quantification showed that the levels of WSSV were significantly lower in the pleopods, stomachs, and guts of shrimp after LvPT dsRNA interference than in those of the controls at 48 and 72 hpi. Our results imply that LvPT plays an important role during WSSV infection of the digestive tract. 展开更多
关键词 Litopenaeus vannamei digestive tract peritrophin-like protein dsRNA interference binding specificity white spot syndrome virus (WSSV) reverse gavage
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A Parameter Determination Method of Distribution Voltage Regulators Considering Tap Change and Voltage Profile
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作者 Yuji Hanai Yasuhiro Hayashi +2 位作者 Junya Matsuki Yoshiaki Fuwa Kenjiro Mori 《Journal of Energy and Power Engineering》 2012年第1期117-125,共9页
This paper proposes a parameter determination method of distribution voltage regulators load ratio control transformers (LRT) and step voltage regulators (SVR) considering the tap change and voltage profile. The m... This paper proposes a parameter determination method of distribution voltage regulators load ratio control transformers (LRT) and step voltage regulators (SVR) considering the tap change and voltage profile. The method takes two procedures in order to simplify the optimization problem and to reduce calculation time. One is to simultaneously determine the control parameters of LRT and SVR minimizing voltage violations and voltage variations. The algorithm is based on particle swarm optimization (PSO), which is one of non-linear optimization methods by using a concept of swarm intelligence. Another is to determine the dead-band width of LRT and SVR on the basis of bi-evaluation of tap change and voltage margin. The concept of a Pareto optimal solution is used for the decision of the best dead-band width. As the results of numerical simulations using distribution network model, the validity of the proposed method has been affirmed. 展开更多
关键词 Distribution network voltage control LRT SVR control parameter deadband PSO.
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一种新型城市道路照明节能电源的研制 被引量:4
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作者 马荣兵 钱斌 李德银 《中国照明电器》 2018年第4期26-29,共4页
本文介绍了一种新型照明节能电源的电路拓扑,分析了其工作原理,给出了电路IGBT器件的非互补斩波控制时序,并进行了电路仿真,该节能电源在工作中不仅可以线性调压,而且没有谐波污染,电路运行稳定可靠,适合于大功率道路照明节能应用场合。
关键词 照明节能电源 非互补斩波控制 线性调压 道路照明
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