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直流型电源分频计数式时间继电器的研究
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作者 周坚 《机床电器》 1997年第6期10-12,共3页
本文介绍了直流型电源分频计数式时间继电器的设计方案。包括CD4060集成电路简介、50Hz时基电路的组成以及方案的可行性分析等。
关键词 电源分频计数 时间继电器 机床 自动控制系统
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计数分频型混合式时间继电器
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作者 李敏俐 《民用飞机设计与研究》 1994年第2期55-57,共3页
关键词 飞机 继电器 计数分频 时间继电器
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计数分频式时间继电器
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作者 李敏俐 《机电元件》 1994年第2期4-6,共3页
介绍了一种计数分频式时间继电器的设计原理。该继电器可获得宽范围的长、短延时,其在体积、精度、可靠性等方面均优于模拟式时间继电器。
关键词 计数分频 模拟式 延时继电器
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一种用EPROM实现的天线方位比较电路
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作者 赵雪梅 杨建军 《微计算机信息》 北大核心 2007年第20期247-248,共2页
本文介绍了实现天线方位码可停在任意角度的实际电路设计,该设计采用数值大小比较器比较模拟天线方位与E-PROM全译码送出的二进制数据(即利用拨码开关设定的数据作为控制输入的角度)。当需要比较的数据达到一致时,便控制了模拟天线即55... 本文介绍了实现天线方位码可停在任意角度的实际电路设计,该设计采用数值大小比较器比较模拟天线方位与E-PROM全译码送出的二进制数据(即利用拨码开关设定的数据作为控制输入的角度)。当需要比较的数据达到一致时,便控制了模拟天线即555振荡器脉冲到分频计数器的输入,分频计数器停止计数,天线停在拨码开关设定的角度,这里实际电路角度控制精确度为1度,如果需要提高精确度,只是增加位数,基本方法不变。 展开更多
关键词 EPROM 数值大小比较器 天线方位码 分频计数 555时基电路
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LS7266R1在数字运动控制器中的应用
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作者 雷江 夏泽中 周祖德 《集成电路应用》 2000年第1期15-17,23,共4页
本文介绍了一种高速计数器LS7266R1,描述了其特点及功能,并介绍了它在高性能数字运动控制器中的应用。
关键词 计数 数字运动控制器 LS7266R1 分频计数
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索尼磁尺的模拟显示电路设计 被引量:3
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作者 杨秋霞 杨景明 吴晓辉 《电力自动化设备》 EI CSCD 北大核心 2004年第4期49-51,共3页
以索尼磁尺在可逆式冷轧机中的应用为例,介绍了索尼磁尺的工作原理,并详细说明了其信号处理和显示电路的设计方法,为索尼磁尺的可靠使用及轧机调试的方便性提供了简单有效的方法。
关键词 索尼磁尺 轨机 分频计数 鉴向
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光传送网中信号速率自动识别的方案研究
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作者 石国武 关卫华 +1 位作者 陈章渊 吴德明 《光通信研究》 北大核心 2002年第5期15-17,21,共4页
文章提出了光传送网中信号速率自动识别的 3种实现方案 ,分析了它们可能遇到的问题和采取的技术方法 ,并对它们进行了对比 .
关键词 光传送网 自动交换光网络 信号速率自动识别 ASON 时钟提取 滤波采样 分频计数
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接收器中并行数据与字节时钟同步的电路设计 被引量:1
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作者 周玲 林福昌 《电子科技》 2006年第5期57-59,共3页
在串并转换接收器中,并行数据在字节时钟的作用下并行输出。如何保证同一时刻输出的并行数据属于同一个字节,即并行数据与字节时钟的同步,是串并转换接受器中的一个关键问题。根据串并转换电路可以使用移位寄存结构,字节时钟可以在串行... 在串并转换接收器中,并行数据在字节时钟的作用下并行输出。如何保证同一时刻输出的并行数据属于同一个字节,即并行数据与字节时钟的同步,是串并转换接受器中的一个关键问题。根据串并转换电路可以使用移位寄存结构,字节时钟可以在串行时钟的基础上使用计数器得到,而计数器又模可变的特点,设计了一种在数据的串并转换中进行并行数据与字节时钟同步的电路,经过理论分析与软件仿真,证明电路性能良好可行。 展开更多
关键词 串并转换 计数分频 时钟同步 同步确认
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HLS时序系统的研制及其在线运行
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作者 李川 曲广治 +2 位作者 高云峰 刘功发 王贵诚 《中国科学技术大学学报》 CAS CSCD 北大核心 2007年第1期87-92,共6页
研制了用于国家同步辐射实验室(NSRL)合肥光源(HLS)二期工程中的时序系统.系统共输出18路时序脉冲列,提供电子枪、微波源、冲击磁铁、切割磁铁、能谱靶、开关磁铁及调制器1~6各一路触发脉冲,另有6路备份时序脉冲输出.各路脉冲... 研制了用于国家同步辐射实验室(NSRL)合肥光源(HLS)二期工程中的时序系统.系统共输出18路时序脉冲列,提供电子枪、微波源、冲击磁铁、切割磁铁、能谱靶、开关磁铁及调制器1~6各一路触发脉冲,另有6路备份时序脉冲输出.各路脉冲周期、延时及脉宽均可步进调节,最小步长为0.1μs,系统定时精度好于10ns.该系统在线稳定运行时间已超过两年,文中介绍了该系统的软、硬件结构. 展开更多
关键词 时序脉冲 前沿抖动时间 计数分频 周期形成器 延时器
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基于FPGA的出租车计费系统设计 被引量:1
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作者 李平 《微型电脑应用》 2015年第7期31-33,5,共3页
分析了出租车计费系统各模块的功能要求、基本原理以及实现方法。设计采用VHDL硬件描述语言进行编程,基于Quartus II9.0软件平台进行编译和仿真。介绍了采用EP2C35F678C8 FPGA芯片设计出租车计费系统的方法,阐述了该计费系统的主要组成... 分析了出租车计费系统各模块的功能要求、基本原理以及实现方法。设计采用VHDL硬件描述语言进行编程,基于Quartus II9.0软件平台进行编译和仿真。介绍了采用EP2C35F678C8 FPGA芯片设计出租车计费系统的方法,阐述了该计费系统的主要组成单元:分频模块、计程模块、计时模块和计费模块等模块的设计,同时,给出了详细的仿真波形,基本实现了出租车基本计费功能,还能模拟汽车启动、停止、暂停等状态,同时,提高了计费系统的可靠性、通用性。 展开更多
关键词 现场可编程门阵列(FPGA) 数码管 计数分频 自顶向下
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A Novel ADC Architecture for Digital Voltage Regulator Module Controllers
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作者 郭健民 张科 +1 位作者 孔明 李文宏 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第12期2112-2117,共6页
The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators' transform from volta... The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators' transform from voltage to frequency,the A/D conversion of ring-ADC achieves good linearity and precise calibration against process variations compared with the delay-line ADC. A differential pulse counting discriminator also helps decrease the power consumption of the ring-ADC. It is fabricated with a Chartered 0.35μm CMOS process, and the measurement results of the integral and differential nonlinearity performance are 0.92LSB and 1.2LSB respectively. The maximum gain error measured in ten sample chips is ± 3.85%. With sampling rate of 500kHz and when the voltage regulator module (VRM) works in steady state, the ring-ADC's average power consumption is 2.56mW. The ring-ADC is verified to meet the requirements for digital VRM controller application. 展开更多
关键词 voltage regulator modules DC-DC ring-ADC delay-line ADC differential pulse counting discrim-inator
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Validation of a FFQ (Food Frequency Questionnaire) for Older People
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作者 Jose Eduardo Corrente Dirce Maria Lobo Marchioni Regina Mara Fisberg 《Journal of Life Sciences》 2013年第8期878-882,共5页
Nutrition data for older adults is an area that has few studies mainly in Brazil. Due to the importance to know the behavior of this age group, the aim of this study was to develop and validate a frequency food questi... Nutrition data for older adults is an area that has few studies mainly in Brazil. Due to the importance to know the behavior of this age group, the aim of this study was to develop and validate a frequency food questionnaire (FFQ) for older people in Brazil. It was considered a sample of 73 subjects from the city of Avar6, Sao Paulo, Brazil, and it was applied three 24-hour recalls and a FFQ developed for adults. Data from the three 24-hour recalls were transformed in nutrient intake as well as the data from FFQ. Statistical analysis was performed in order to get correlations between data from the mean of three 24-hour recalls and FFQ for some nutrients. It was found high correlations among them, concluding that the FFQ is valid to get nutrient intakes for older people. 展开更多
关键词 Older people food frequency questionnaire CORRELATIONS nutrient intake.
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A novel method for integrating chromatographic fingerprint analytical units of Chinese materia medica:the matching frequency statistical moment method
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作者 LI Haiying PAN Xue +4 位作者 WANG Mincun LI Wenjiao HE Peng HUANG Sheng HE Fuyuan 《Digital Chinese Medicine》 CAS 2024年第3期294-308,共15页
Objective To facilitate the quality evaluation suitable for the unique characteristics of Chinese materia medica(CMM)by developing and implementing a novel approach known as the matching frequency statistical moment(M... Objective To facilitate the quality evaluation suitable for the unique characteristics of Chinese materia medica(CMM)by developing and implementing a novel approach known as the matching frequency statistical moment(MFSM)method.Methods This study established the MFSM method.To demonstrate its effectiveness,we applied this novel approach to analyze Danxi Granules(丹膝颗粒,DXG)and its constituent herbal materials.To begin with,the ultra-performance liquid chromatography(UPLC)was applied to obtain the chromatographic fingerprints of DXG and its constituent herbal materi-als.Next,the MFSM was leveraged to compress and integrate them into a new fingerprint with fewer analytical units.Then,we characterized the properties and variability of both the original and integrated fingerprints by calculating total quantum statistical moment(TQSM)parameters,information entropy and information amount,along with their relative standard deviation(RSD).Finally,we compared the TQSM parameters,information entropy and infor-mation amount,and their RSD between the traditional and novel fingerprints to validate the new analytical method.Results The chromatographic peaks of DXG and its 12 raw herbal materials were divided and integrated into peak families by the MFSM method.Before integration,the ranges of the peak number,three TQSM parameters,information entropy and information amount for each peak or peak family of UPLC fingerprints of DXG and its 12 raw herbal materials were 95.07−209.73,9390−183064μv·s,5.928−21.33 min,22.62−106.69 min^(2),4.230−6.539,and 50530−974186μv·s,respectively.After integration,the ranges of these parameters were 10.00−88.00,9390−183064μv·s,5.951−22.02 min,22.27−104.73 min^(2),2.223−5.277,and 38159−807200μv·s,respectively.Correspondingly,the RSD of all the aforementioned pa-rameters before integration were 2.12%−9.15%,6.04%−49.78%,1.15%−23.10%,3.97%−25.79%,1.49%−19.86%,and 6.64%−51.20%,respectively.However,after integration,they changed to 0.00%,6.04%−49.87%,1.73%−23.02%,3.84%−26.85%,1.17%−16.54%,and 6.40%−48.59%,respectively.The results demonstrated that in the newly integrated fingerprint,the analytical units of constituent herbal materials,information entropy and information amount were significantly reduced(P<0.05),while the TQSM parameters remained unchanged(P>0.05).Additionally,the RSD of the TQSM parameters,information entropy,and information amount didn’t show significant difference before and after integration(P>0.05),but the RSD of the number and area of the integrated analytical units significantly decreased(P<0.05).Conclusion The MFSM method could reduce the analytical units of constituent herbal mate-rials while maintain the properties and variability from their original fingerprint.Thus,it could serve as a feasible and reliable tool to reduce difficulties in analyzing multi-compo-nents within CMMs and facilitating the evaluation of their quality. 展开更多
关键词 Chromatographic fingerprints Analytical units Matching frequency statistical moment method Chinese materia medica Danxi Granule(丹膝颗粒 DXG) Quality evaluation
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Application of Bayesian approach to hydrological frequency analysis 被引量:7
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作者 LIANG ZhongMin LI BinQuan +1 位作者 YU ZhongBo CHANG Wen Juan 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第5期1183-1192,共10页
An existing Bayesian flood frequency analysis method is applied to quantile estimation for Pearson type three (P-III) probability distribution. The method couples prior and sample information under the framework of Ba... An existing Bayesian flood frequency analysis method is applied to quantile estimation for Pearson type three (P-III) probability distribution. The method couples prior and sample information under the framework of Bayesian formula, and the Markov Chain Monte Carlo (MCMC) sampling approach is used to estimate posterior distributions of parameters. Different from the original sampling algorithm (i.e. the important sampling) used in the existing approach, we use the adaptive metropolis (AM) sampling technique to generate a large number of parameter sets from Bayesian parameter posterior distributions in this paper. Consequently, the sampling distributions for quantiles or the hydrological design values are constructed. The sampling distributions of quantiles are estimated as the Bayesian method can provide not only various kinds of point estimators for quantiles, e.g. the expectation estimator, but also quantitative evaluation on uncertainties of these point estimators. Therefore, the Bayesian method brings more useful information to hydrological frequency analysis. As an example, the flood extreme sample series at a gauge are used to demonstrate the procedure of application. 展开更多
关键词 Bayesian theory hydrological frequency analysis Markov Chain Monte Carlo prior distribution posterior distribution
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