期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
利用两台单工机实现通信中转的方法
1
作者 刘小钢 《气象与减灾研究》 1997年第2期47-48,共2页
关键词 单工机 B A 双工 话音信号 与非门 通信 发射状态 接收状态 转台
下载PDF
CMOS Mixers for 2.4GHz WLAN Transceivers 被引量:2
2
作者 池保勇 石秉学 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第5期472-475,共4页
A down-conversion mixer and an up-conversion mixer for 2.4GHz WLAN transceivers are presented.The down-conversion mixer uses a class-AB input stage to get high linearity and to realize input impedance matching and sin... A down-conversion mixer and an up-conversion mixer for 2.4GHz WLAN transceivers are presented.The down-conversion mixer uses a class-AB input stage to get high linearity and to realize input impedance matching and single-ended to differential conversion.The mixers are implemented in 0.18μm CMOS process.The measured results are given to show their performance. 展开更多
关键词 WLAN transceivers MIXER Gilbert cell
下载PDF
Two Different Role Division Control Strategies for Torque and Axial Force of Conical Bearingless Switched Reluctance Motor 被引量:1
3
作者 HAO Zhenyang MIAO Wei +1 位作者 CAO Xin ZHANG Qiyao 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第6期848-857,共10页
Although the five-degree-of-freedom magnetic levitation system composed of two conical bearingless switched reluctance motors(CBSRMs)owns the simplest structure,the torque and levitation forces are coupled greatly.The... Although the five-degree-of-freedom magnetic levitation system composed of two conical bearingless switched reluctance motors(CBSRMs)owns the simplest structure,the torque and levitation forces are coupled greatly.Therefore,it is difficult to make the rotor rotate and be fully levitated simultaneously.To solve this problem,two different role division control strategies are proposed in this paper,i.e.individual role division and mutual role division control strategies.The difference between them is the selection of motor which controls the torque or the axial force.In order to understand the characteristics of control variables,the principle and mathematical model of CBSRM are introduced.After that,two control strategies are explained in detail.To verify the demonstrated performance,the simulations are completed with MATLAB/Simulink. 展开更多
关键词 five-degree-of-freedom magnetic levitation conical bearingless switched reluctance motor(CBSRM) individual role division control mutual role division control
下载PDF
Novel method for detection of anomalous structure characteristics of ID precision ultrathin monocrystalline silicon section cutting tool
4
作者 陈宗农 郭明 +1 位作者 王庆九 余学功 《Journal of Zhejiang University Science》 CSCD 2002年第3期263-267,共5页
The structure characteristics of ID precision ultrathin monocrystalline silicon section cutting machine tool spindle with force monitoring bearings functioning as force measuring sensors were detected with the new H... The structure characteristics of ID precision ultrathin monocrystalline silicon section cutting machine tool spindle with force monitoring bearings functioning as force measuring sensors were detected with the new Hilbert theory based signal wave envelope detection method, presented to replace the conventional hardware device in order to ensure that the signal is measured online with high fidelity. According to the probability of anomalous incidents in the cutting process, a mathematical recognition model has been designed and verified on an STC 22ID machine. 展开更多
关键词 Machine tool spindle BEARING Monocrystalline silicon section Signal analysis
下载PDF
Development of a one-axis manipulator for laser-assisted machining 被引量:1
5
作者 KIM Dong-hyeon LEE Choon-man 《Journal of Central South University》 SCIE EI CAS 2013年第2期378-384,共7页
Laser-assisted machining has been considered as a new alternative machining method of difficult-to-cut materials. A laser module with one-axis manipulator is developed to focus on preheating laser beam effectively. Fi... Laser-assisted machining has been considered as a new alternative machining method of difficult-to-cut materials. A laser module with one-axis manipulator is developed to focus on preheating laser beam effectively. First of all, the thermal characteristic analysis was performed to verify the importance of laser module location. Laser module should be moved within 1 mm. Analysis conditions of three positions in driving range of the one-axis manipulator are selected. And a C coupling is used as a connection device for spindle and laser module. An initial model has one C coupling, and the number of C coupling has been increased from 1 to 2 in an improved model. And the analysis is carried out again for the one-axis manipulator. The results of the static analysis, the maximum displacement and the maximum stress are decreased by 22% and 11%, respectively, for the improved model when the laser module is located at farthest away from the spindle unit. As a result of the modal analysis, the first natural frequency mode is increased by 13%, 18% and 12% at these positions of the improved model, respectively. The harmonic analysis of the improved model was performed by analyzing the results of the modal analysis. The maximum deformation was 0.33 mm in driving unit at 222 Hz. And the maximum compliance of the ISO axis direction was 0.23 mm/N. Finally, the one-axis manipulator has been fabricated successfully using the analysis result. 展开更多
关键词 finite element analysis (FEA) laser-assisted machining MANIPULATOR
下载PDF
Optimal Batching Structures of Single Machine Scheduling
6
作者 FENG Mi-luo 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第1期132-137,共6页
A batch is a subset of jobs which must be processed jointly in either serial or parallel form. For the single machine, batching, total completion time scheduling problems, the algorithmic aspects have been extensively... A batch is a subset of jobs which must be processed jointly in either serial or parallel form. For the single machine, batching, total completion time scheduling problems, the algorithmic aspects have been extensively studied in the literature. This paper presents the optimal hatching structures of the problems on the batching ways: all jobs in exactly N(arbitrary fix batch number and 1 〈 N 〈 n) batches. 展开更多
关键词 SCHEDULING BATCHING batch number total complete time
下载PDF
New lightweight geomaterials:Biocemented sand mixed with expanded polystyrene beads 被引量:4
7
作者 XIAO Yang HE Xiang LIU HanLong 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第7期1118-1120,共3页
Lightweight geomaterial(LWGM)possesses such merit characteristics as low unit weight,environmental protection(recycling these materials instead of stockpiling them),buffering mechanical property and thermal insula... Lightweight geomaterial(LWGM)possesses such merit characteristics as low unit weight,environmental protection(recycling these materials instead of stockpiling them),buffering mechanical property and thermal insulation[1].LWGM,an attractive substitute for earth fills, 展开更多
关键词 lightweight beads polystyrene expanded attractive instead recycling Portland insulation hydraulic
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部