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双引擎飞艇发动机转速测量与保持的研究和应用 被引量:3
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作者 石剑锋 谢少荣 《机电一体化》 2004年第4期30-32,共3页
双引擎飞艇在飞行过程中,由于多种因素的作用,左右发动机的转速常常不能保持一致,对飞艇的巡航有很大的影响。该文通过对飞艇发动机速度的调节机构的分析,得到飞艇左右发动机转速不一样的机械原因,并提出了用霍尔传感器非接触测量飞艇... 双引擎飞艇在飞行过程中,由于多种因素的作用,左右发动机的转速常常不能保持一致,对飞艇的巡航有很大的影响。该文通过对飞艇发动机速度的调节机构的分析,得到飞艇左右发动机转速不一样的机械原因,并提出了用霍尔传感器非接触测量飞艇发动机转速,通过单片机分析处理,调节左右发动机转速,使其保持一致。通过试验,本系统取得较好效果。 展开更多
关键词 单片机 转速保持 脉宽调制 双引擎飞艇 发动机 转速测
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用簧片式测转速装置检测内藏微电机的小家电产品之转速
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作者 庄表中 《振动与冲击》 EI CSCD 2000年第3期84-84,共1页
关键词 水家电 转速 簧片式转速装置
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单片机在转速巡测数据采集与处理系统中的应用
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作者 曾慧玲 周庆忠 李志强 《计算机系统应用》 1998年第5期44-45,共2页
本文应用单片机为核心设计构成的转速巡测数据采集与处理系统,可快速地采集与处理多点测量值,较好地实现了巡测过程的自动化和智能化,具有工作稳定可靠、操作方便和性价比高的特点。
关键词 单片机 转速 数据采集系统 数据处理系统
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Lauda循环水浴器制冷故障分析与处理
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作者 李承靖 袁伟 +5 位作者 杨波 李阳 王政炜 刘琦 苏会忠 李鑫 《设备管理与维修》 2017年第10期50-51,共2页
Lauda循环水浴器制冷故障报警,分析故障原因,依据故障排查原则,对线路及各个外围传感器逐个排查,运用工具检测与理论计算分析相结合,最终确定故障点并进行了故障处理,设备恢复正常。
关键词 Lauda 循环水浴 制冷故障 温度传感器 转速测
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The Application of Reverse Transcription-loop-mediated Isothermal Amplification for the Rapid Detection of Maize Chlorotic Dwarf Virus
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作者 徐颖 张峰 +1 位作者 于莹 邱志君 《Agricultural Science & Technology》 CAS 2017年第12期2450-2453,共4页
Maize chlorotic dwarf virus (MCDV) is a quarantine pest as approved by Chinese government. A rapid, sensitive and specific MCDV detection method using reverse transcription-loop-mediated isothermal amplification (R... Maize chlorotic dwarf virus (MCDV) is a quarantine pest as approved by Chinese government. A rapid, sensitive and specific MCDV detection method using reverse transcription-loop-mediated isothermal amplification (RT-LAMP) was estab- lished in this study. Based on the sequence of MCDV coat protein coding gene, specific primers were designed and similar sensitivities were observed between RT- LAMP and RT-PCR, except that RT-LAMP was quicker, and the reaction could be finished within 1 h. In addition, the presence or absence of the fluorescent display in daylight allows naked easy detection of the amplification of MCDV genomic RNA using calcein. The RT-LAMP assay was applied successfully to detect MCDV in maize seeds, and the result by the addition of calcein was consistent with the result detected by the real time turbidimeter. 展开更多
关键词 Maize chlorotic dwarf virus (MCDV) Reverse transcription loop-mediatedisothermal amplification (RT-LAMP) Rapid detection
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Development of a simple RPM measurement system 被引量:2
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作者 Akash Kumar Anindya Debnath +4 位作者 Antar Banik Kabirul Islam Mondal Partha Pratim Biswas Rik Bhattacharyya T K Maiti 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2020年第2期193-196,共4页
The design and development of a timer based revolution per minute(RPM)measurement system were described in this paper.The rotating shaft of a dc motor was used to measure the RPM and timer integrated circuit(IC)555 wa... The design and development of a timer based revolution per minute(RPM)measurement system were described in this paper.The rotating shaft of a dc motor was used to measure the RPM and timer integrated circuit(IC)555 was used in astable mode.The frequency of timer output waveform measured by a digital storage oscilloscope(DSO)is almost linearly proportional to the RPM of rotating shaft,and the RPM also linearly varies with the change of the external input voltage level.Hence the linear relationship between the frequency of timer output waveform and the RPM can be obtained.The main advantages of this developed system are linear input-output relationship,small size,easy to carry and cost effective. 展开更多
关键词 IC 555 astable multivibrator RPM measurement
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单片机在转速巡测系统中的应用 被引量:4
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作者 曾慧玲 《电子技术(上海)》 北大核心 1998年第7期27-28,共2页
文章介绍了一种以单片机为核心构成的转速巡测数据采集与处理系统,该系统可对生产过程中多路测量点的转速以在线的方式快速地进行数据的采集与处理,实现了巡测过程的自动化和智能化,具有工作稳定可靠、操作灵活方便和性价比高的特点... 文章介绍了一种以单片机为核心构成的转速巡测数据采集与处理系统,该系统可对生产过程中多路测量点的转速以在线的方式快速地进行数据的采集与处理,实现了巡测过程的自动化和智能化,具有工作稳定可靠、操作灵活方便和性价比高的特点,较好地满足了现代工业生产发展的需要。 展开更多
关键词 单片机 转速 多路采集 数据处理
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A new method for high precsion instantaneous speedmeasurement of hydraulic system 被引量:1
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作者 LIU Jia-min GU Li-chen SUN Yu 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第4期307-314,共8页
The instantaneous speed of a hydraulic system contains a wealth of operational information,and its accurate extraction is the basis for condition monitoring and fault diagnosis.In order to solve the problem of high ha... The instantaneous speed of a hydraulic system contains a wealth of operational information,and its accurate extraction is the basis for condition monitoring and fault diagnosis.In order to solve the problem of high hardware requirement for instantaneous speed measurement based on data acquisition card,a new method of high precision measurement is proposed.In this method,the time-displacement information of each tooth is obtained from the pulsed square wave signal of the gear disk collected by magnetoelectric sensors.The time-displacement curve is interpolated by the cubic spline interpolation method,and then the instantaneous speed is calculated by the five-point digital differential formula.The experimental results show that the method improves the speed measurement resolution and reduces the quantization error.The high precision instantaneous speed signal can also be acquired by hardware devices with less teeth and low sampling frequency.The related research results provide a theoretical basis and a method for improving the accuracy of instantaneous speed measurement. 展开更多
关键词 instantaneous speed measurement variable speed hydraulic system cubic spline interpolation five-point digital differentiation
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Method of measuring rotation speed of high spinning projectile based on plane magnetic induction coil
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作者 CAO Yong-hong XUE Kai-yun JING Yong-qiang 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第4期317-323,共7页
For the test of rotation speed of high spinning projectile, the general formula of the motional electromotive force (MEMF) of planar magnetic induction coil (PMIC) is derived in case of 3D rotation in a stable mag... For the test of rotation speed of high spinning projectile, the general formula of the motional electromotive force (MEMF) of planar magnetic induction coil (PMIC) is derived in case of 3D rotation in a stable magnetic field. Under a reasona-ble assumption, the MEMF of PMIC is simplified after the aforementioned general formula is used to calculate high spinning PMIC in the geomagnetic field environment. The determination approach of half-cycle is discussed and the method of rotation speed test is studied, and a test is conducted in the paper. The rotation speed curve obtained by the approach in this paper is consistent with the curve by telemetry. 展开更多
关键词 planar magnetic induction coil 3D rotation high spinning projectile determination approach of half-cycle rotation speed test method
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Design of driving wheel speed test device based on magnetoelectric sensor 被引量:1
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作者 HOU Zhi-wei CHEN Chang-xin +2 位作者 MA Tie-hua WANG Yu JIAO Bin 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2020年第2期186-192,共7页
In order to study the transmission efficiency of engine and optimize the structure of driving wheel,the rotational speed storage test device of driving wheel in tracked vehicle based on magnetoelectric sensor was desi... In order to study the transmission efficiency of engine and optimize the structure of driving wheel,the rotational speed storage test device of driving wheel in tracked vehicle based on magnetoelectric sensor was designed.The device consisted of a mounting bracket,a sensor and a tester.The mounting bracket was installed in vehicle body after fixing the tester and sensor to mounting bracket beside the driving wheel.Using the storage test instrument,the wireless trigger technology was applied to synchronously record and stored the rotational speed data of the driving wheel in tracked vehicle.After the experiment was finished,the data was read out through the upper computer.Both valid data and satisfactory results were obtained through both simulated and actual vehicle tests. 展开更多
关键词 tracked vehicle storage test driving wheel test magnetoelectric sensor
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Research on variable frequency and speed regulation of motor system based on PLC
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作者 Min ZHENG 《International Journal of Technology Management》 2015年第2期41-43,共3页
This paper presents the composition, control scheme and signal processing method of frequency conversion motor speed testing system based on $7-200 PLC, and design the hardware circuit, the trapezoidal chart procedure... This paper presents the composition, control scheme and signal processing method of frequency conversion motor speed testing system based on $7-200 PLC, and design the hardware circuit, the trapezoidal chart procedure and touch screen display program. The debugging test shows that the system is simple, practical, and related design work has laid the foundation for the future. 展开更多
关键词 INVERTER frequency control touch screen $7-200 PLC PID
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Continuous on-line adaptation of the rotor time constant in FOC induction machine system
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作者 齐昕 Ma Xianghua +1 位作者 Wang Changsong Xi Anmin 《High Technology Letters》 EI CAS 2013年第3期254-260,共7页
Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation ... Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation of the rotor field. A new approach serves for rotor time constant on-line adaptation by setting the stator current to be zero for a short period. A smooth eorrector is designed to prevent ab- normal detection result from making adaptation. Impact of zero current duration on detection error and rotor speed is analyzed by experiments. 展开更多
关键词 rotor time constant field oriented control (FOC) on-line adaptation inductionmotor
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New Rectangular-like Columns: Advanced Swing Jet Grouting Test and Quality Confirmation
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作者 Tsutomu Tsuchiya, Hiroyuki Abe Kazuhiko Komatsu 《Journal of Civil Engineering and Architecture》 2018年第3期213-224,共12页
Ordinary columns of jet grouting are circular or fan-shaped. But in recent years, such shapes as candy-shaped columns were put to practical use. They are constructed by switching the rotational speed of the stem in on... Ordinary columns of jet grouting are circular or fan-shaped. But in recent years, such shapes as candy-shaped columns were put to practical use. They are constructed by switching the rotational speed of the stem in one rotation. We applied this method to swing jet grouting. That is, we changed the rotational speeds in the swing jet grouting to make elongated columns near rectangle. The test construction was succeeded and the columns’ shapes conformed to those designed. In addition, the quality was confirmed to be as good as ordinary columns. Radii (distances from center to outer ends) were 1.03 to 1.21 times as large as those designed. Improvement ratios were 95% or more in any position. Strengths were varied by location, but they satisfied design strength 1.5 kN/m2 at any position. We concluded that this new column can be applied to practice in the same way as ordinary columns. 展开更多
关键词 Swing jet grouting rectangular-like column flexible shape efficiency
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Effects of automatic variable preload device on performance of spindle 被引量:1
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作者 KIM Dong-Hyeon LEE Choon-Man 《Journal of Central South University》 SCIE EI CAS 2012年第1期150-154,共5页
To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed regions.A... To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed regions.An automatic variable preload device was fabricated using an eccentric mass.By installing the fabricated device on a spindle,the effect of the automatic variable preload device on the performance of the spindle was analyzed.In the results of the vibration measurement of the spindle,the vibration is increased by 20%-37% according to measurement points at the maximum rotation speed of 5 000 r/min.And,in the results of the noise measurement of the spindle,the spindle rotation speed is increased by about 1.9% and 1.5% at the front and side of the spindle,respectively.Based on the results of this analysis,an improved method that reduces such effects on the performance of the spindle is proposed. 展开更多
关键词 machine tool spindle automatic variable preload device VIBRATION noise
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Effect of ball-milling parameter on mechanical and damping properties of sintered Mg-Zr alloy
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作者 刘子利 刘希琴 +2 位作者 沈平 朱秀荣 孟亮 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第11期2092-2095,共4页
Effects of ball-milling parameter on structures and properties of sintered Mg-l.5Zr (mass fraction, %) alloy were researched by metallographic analysis, mechanical properties tests and DMA technology. The results in... Effects of ball-milling parameter on structures and properties of sintered Mg-l.5Zr (mass fraction, %) alloy were researched by metallographic analysis, mechanical properties tests and DMA technology. The results indicate that with 310 r/min rotation speed, the microstructure of the sintered alloy is greatly refined, and Zr-phase distributes uniformly. The micro-hardness, bending strength and damping capacities are the greatest under 310 r/min rotation speed. The damping peak of sintered Mg-l.5Zr alloy increases with increasing frequency under the testing conditions. The relaxation time meets the Arrhenius relationship, and shows the characteristics of relaxation damping. 展开更多
关键词 Mg-Zr alloy ball-milling parameter damping capacities
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Thermo-mechanical properties of bowl-shaped grinding wheel and machining error compensation for grinding indexable inserts
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作者 张祥雷 姚斌 +3 位作者 陈彬强 孙维方 王萌萌 罗琪 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第10期3830-3836,共7页
In order to meet the technical requirements of grinding the circumferential cutting edge of indexable inserts, thermo-mechanical properties of bowl-shaped grinding wheel in high speed grinding process and the influenc... In order to meet the technical requirements of grinding the circumferential cutting edge of indexable inserts, thermo-mechanical properties of bowl-shaped grinding wheel in high speed grinding process and the influence of dimension variations of the grinding wheel on machining accuracy were investigated. Firstly, the variation trends of the dimension due to centrifugal force generated in different wheel speeds were studied and the effect of stress stiffening and spin softening was presented. Triangular heat flux distribution model was adopted to determine temperature distribution in grinding process. Temperature field cloud pictures were obtained by the finite element software. Then, dimension variation trends of wheel structure were acquired by considering the thermo-mechanical characteristic under combined action of centrifugal force and grinding heat at different speeds. A method of online dynamic monitoring and automatic compensation for dimension error of indexable insert was proposed. By experimental verification, the precision of the inserts satisfies the requirement of processing. 展开更多
关键词 bowl-shaped grinding wheel thermo-mechanical properties indexable insert machining accuracy COMPENSATION
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Temperature effect on translocation speed and capture rate of nanopore-based DNA detection 被引量:2
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作者 ZHANGYin WU GenSheng +5 位作者 MA Jian YUAN ZhiShan SI Wei LIU Lei SHA JingJie CHEN YunFei 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第3期519-525,共7页
We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are fir... We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are first considered.The DNA molecule translocation time is measured to be 2.44 ms at 2°C in both chambers,which is 1.57 times longer than at 20°C.Then the temperature difference effect is characterized in both chambers.The results show that the DNA translocation speed can be slowed down as long as one side temperature is lowered,irrespective of the temperature gradient direction.This indicates that the thermophoretic driving force generated by a temperature gradient has no obvious effect on the threading speed of DNA molecules,while the main reason for the slowed DNA translocation speed is the increased viscosity.Interestingly,the capture rate of DNA molecules is enhanced under a temperature gradient condition,and the capture rate during DNA translocation from hot side at 21°C to cold one at 2°C is 1.7 times larger than that under the condition of both chambers at 20°C.Finally,an optimized configuration is proposed to acquire higher capture rates and lower DNA translocation speeds. 展开更多
关键词 NANOPORE DNA detection temperature translocation speed capture rate
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Probing particle removal in brush scrubber cleaning with fluorescence technique 被引量:3
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作者 HUANG YaTing LI Yang +1 位作者 GUO Dan MENG ChunLing 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第12期2994-3000,共7页
Brush scrubber cleaning is widely used for post chemical mechanical polishing(CMP)cleaning in semiconductor manufacturing.In this study,an experimental system based on fluorescence technique and particle-tracking velo... Brush scrubber cleaning is widely used for post chemical mechanical polishing(CMP)cleaning in semiconductor manufacturing.In this study,an experimental system based on fluorescence technique and particle-tracking velocimetry(PTV)technique was employed to characterize the particle removal displacement and velocity in the interface between a transparent copper film and a porous polyvinyl alcohol(PVA)brush during the cleaning process.Several different cleaning conditions including rotation speeds,loading pressure and cleaning agent were examined and the particle removal rate was compared.Elastic and friction removal,hydrodynamic removal and mixed-type removal are the three types of particle removal.Particles with an arc trace and uniform velocity curves were removed by friction and elastic force which were related to the brush load.Particles with a random trace and fluctuant velocity curves were removed by hydrodynamic force which was determined by the brush rotation speed.The increase of particle removal rate(PRR)with brush rotation speed is a logistic function.It is easier to improve PRR by increasing the brush load or by adding surfactant than by increasing the brush rotation speed. 展开更多
关键词 brush-scrub post CMP(chemical mechanical polishing) cleaning particle removal fluorescence technique
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Quasi-equilibrium glide adaptive guidance for hypersonic vehicles 被引量:31
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作者 XU MingLiang CHEN KeJun +1 位作者 LIU LuHua TANG GuoJian 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第3期856-866,共11页
The entry-glide guidance strategy for hypersonic vehicles that can satisfy both terminal and path constraints is investigated in this paper.We propose a quasi-equilibrium glide adaptive guidance methodology based on t... The entry-glide guidance strategy for hypersonic vehicles that can satisfy both terminal and path constraints is investigated in this paper.We propose a quasi-equilibrium glide adaptive guidance methodology based on the quasi-equilibrium glide condition(QEGC),which innovatively utilizes the quasi-equilibrium glide phenomenon in lifting entry.With the aid of QEGC,both range and terminal velocity can be predicted analytically with high precision.The path constraints are converted into angle of attack constraints,which has been difficult to realize by using traditional predictive guidance methods.The algorithm is independent of the standard trajectory.All the guidance commands,including the bank angle and the angle of attack,are calculated analytically in real time,which endows the algorithm with sufficient adapbility.The results of a CAV-H vehicle guidance test show that the algorithm leads the vehicle along a quasi-equilibrium glide trajectory satisfying both the terminal and path constraints and has sufficient flexibility for occasional mission changes.Furthermore,the robustness of the guidance algorithm under disturbances is validated through a Monte Carlo simulation. 展开更多
关键词 hypersonic vehicles entry guidance quasi-equilibrium glide adaptive guidance analytical predictor-corrector (APC)
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PRICING CONVERTIBLE BONDS AND CHANGE OF PROBABILITY MEASURE
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作者 JIA Zhaoli ZHANG Shuguang 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2013年第6期968-977,共10页
The changes of numeraire can be used as a very powerful tool in pricing contingent claims in the context of a complete market.By using the method of numeraire changes to evaluate convertible bonds when the value of fi... The changes of numeraire can be used as a very powerful tool in pricing contingent claims in the context of a complete market.By using the method of numeraire changes to evaluate convertible bonds when the value of firm,and those of zero-coupon bonds follow general adapted stochastic processes in this paper,using Ito theorem and Gisanov theorem.A closed-form solution is derived under the stochastic volatility by using fast Fourier transforms. 展开更多
关键词 Convertible bonds European option numeraire changes stochastic volatility model.
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