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Microenvironment and electronic state modulation of Pd nanoparticles within MOFs for enhancing low-temperature activity towards DCPD hydrogenation
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作者 Zhiyuan Liu Changan Wang +8 位作者 Ping Yang Wei Wang Hongyi Gao Guoqing An Siqi Liu Juan Chen Tingting Guo Xinmeng Xu Ge Wang 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第9期112-122,共11页
Precise control of the local environment and electronic state of the guest is an important method of controlling catalytic activity and reaction pathways.In this paper,guest Pd NPs were introduced into a series of hos... Precise control of the local environment and electronic state of the guest is an important method of controlling catalytic activity and reaction pathways.In this paper,guest Pd NPs were introduced into a series of host UiO-67 MOFs with different functional ligands and metal nodes,the microenvironment and local electronic structure of Pd is modulated by introducing bipyridine groups and changing metal nodes(Ce_(6)O_(6) or Zr_(6)O_(6)).The bipyridine groups not only promoted the dispersion Pd NPs,but also facilitated electron transfer between Pd and UiO-67 MOFs through the formation of Pd-N bridges.Compared with Zr6 clusters,the tunability and orbital hybridisation of the 4f electronic structure in the Ce_(6) clusters modulate the electronic structure of Pd through the construction of the Ce-O-Pd interfaces.The optimal catalyst Pd/UiO-67(Ce)-bpy presented excellent low-temperature activity towards dicyclopentadiene hydrogenation with a conversion of>99% and a selectivity of>99%(50℃,10 bar).The results show that the synergy of Ce-O-Pd and Pd-N promotes the formation of active Pd^(δ+),which not only enhances the adsorption of H_(2) and electron-rich C=C bonds,but also contributes to the reduction of proton migration distance and improves proton utilization efficiency.These results provide valuable insights for investigating the regulatory role of the host MOFs,the nature of host-guest interactions,and their correlation with catalytic performance. 展开更多
关键词 Interface regulation Pd^(δ+) MICROENVIRONMENT Electronic state HYDROGENATION
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Frequency Regulation of Alternating Current Microgrid Based on Hierarchical Control Using Fuzzy Logic
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作者 WU Xueyang SHAN Yinghao SHEN Bo 《Journal of Donghua University(English Edition)》 CAS 2024年第5期536-544,共9页
An alternating current(AC)microgrid is a system that integrates renewable power,power converters,controllers and loads.Hierarchical control can manage the frequency of the microgrid to prevent imbalance and collapse o... An alternating current(AC)microgrid is a system that integrates renewable power,power converters,controllers and loads.Hierarchical control can manage the frequency of the microgrid to prevent imbalance and collapse of the system.The existing frequency control methods use traditional proportion integration(PI)controllers,which cannot adjust PI parameters in real-time to respond to the status changes of the system.Hierarchical control driven by fuzzy logic allows real-time adjustment of the PI parameters and the method used a two-layer control structure.The primary control used droop control to adjust power distribution,and fuzzy logic was used in the voltage loop of the primary control.The secondary control was added to make up for frequency deviation caused by droop control,and fuzzy logic was used in the secondary frequency control to deal with the dynamic change of frequency caused by the disturbances of loads.The proposed method was simulated in Matlab/Simulink.In the primary control,the proposed method reduced the total harmonic distortion(THD)of two cycles of the output voltage from 4.19%to 3.89%;in the secondary control,the proposed method reduced the frequency fluctuation of the system by about 0.03 Hz and 0.04 Hz when the load was increased and decreased,respectively.The results show that the proposed methods have a better effect on frequency maintenance and voltage control of the AC microgrid. 展开更多
关键词 fuzzy logic hierarchical control frequency regulation droop control alternating current(AC)microgrid
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新型节电防窃抽油机拖动装置的应用
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作者 王军民 龚新强 +1 位作者 李淑萍 薄保中 《石油工业技术监督》 2002年第2期31-32,共2页
介绍了一种新型节电防窃抽油机拖动装置及其油田现场应用情况。这种装置由 1.14kV超高转差异步电动机和控制保护装置构成 ,与配电保护变压器和卡锁装置跌落熔断器一起组成采油井电力及驱动系统的节电、防窃电系统。现场应用表明 ,这种... 介绍了一种新型节电防窃抽油机拖动装置及其油田现场应用情况。这种装置由 1.14kV超高转差异步电动机和控制保护装置构成 ,与配电保护变压器和卡锁装置跌落熔断器一起组成采油井电力及驱动系统的节电、防窃电系统。现场应用表明 ,这种装置节电效果显著 ,同时解决了油井的窃电问题 。 展开更多
关键词 抽油机 防窃 电节 拖动装置 应用
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Physical layer design of wireless sensor network nodes 被引量:5
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作者 钟子果 胡爱群 王丹 《Journal of Southeast University(English Edition)》 EI CAS 2006年第1期21-25,共5页
Major consideration dimensions for the physical layer design of wireless sensor network (WSN) nodes is analyzed by comparing different wireless communication approaches, diverse mature standards, important radio fre... Major consideration dimensions for the physical layer design of wireless sensor network (WSN) nodes is analyzed by comparing different wireless communication approaches, diverse mature standards, important radio frequency (RF) parameters and various microcontroller unit (MCU) solutions. An implementation of the WSN node is presented with experimental results and a novel "one processor working at two frequencies" energy saving strategy. The lifetime estimation issue is analyzed with consideration to the periodical listen required by common WSN media access control (MAC) algorithms. It can be concluded that the startup time of the RF which determines the best sleep time ratio and the shortest backoff slot time of MAC, the RF frequency and modulation methods which determinate the RX and TX current, and the overall energy consumption of the dual frequency MCU SOC ( system on chip) are the most essential factors for the WSN node physical layer design. 展开更多
关键词 wireless sensor network node physical layer radio frequency energy consumption node lifetime
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Multiple Node Upset in SEU Hardened Storage Cells 被引量:4
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作者 刘必慰 郝跃 陈书明 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第2期244-250,共7页
We study the problem of multiple node upset (MNU) using three-dimensional device simulation. The results show the transient floating node and charge lateral diffusion are the key reasons for MNU. We compare the MNU ... We study the problem of multiple node upset (MNU) using three-dimensional device simulation. The results show the transient floating node and charge lateral diffusion are the key reasons for MNU. We compare the MNU with multiple bit upset (MBU),and find that their characteristics are different. Methods to avoid MNU are also discussed. 展开更多
关键词 multiple node upset hardened cell charge collection
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Research on thermocouple transient thermometry technology based on LabVIEW 被引量:3
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作者 王瑞 张志杰 +2 位作者 赵晨阳 穆欣荣 翟永 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第2期111-115,共5页
Based on LabVlEW platform, a distributed dynamic storage testing system is designed for measuring transient high temperature signals of explosion field. Using a highpower semiconductor laser as heat source, a traceabl... Based on LabVlEW platform, a distributed dynamic storage testing system is designed for measuring transient high temperature signals of explosion field. Using a highpower semiconductor laser as heat source, a traceable dynamic calibration system is established to perform dynamic calibration of thermocouples. With quantumbehaved particle swam optimization (QP-SO) algorithm on MATLAB platform, a model of dynamic compensation filter is established. It is used by LabVIEW that calls MATLAB Script nodes or COM components to accomplish the mixed programming of LabVIEW and MATLAB, further to compensate the temperature values of the thermocouples dynamically. The experimental results show that the technique that combines temperature measurement system with LabVIEW platform is applied well in testing the explosion temperature of ther mobaric weaponry and makes the compensation values closer to the actual signals. 展开更多
关键词 temperature test dynamic calibratiom MATLAB Script node COM eomponent thermoeouple
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Application study of dynamic voltage scaling policies
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作者 卜爱国 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期406-409,共4页
Based on the fundamental relationship among the circuit power, the circuit delay and the supply voltage, four theorems associated with the application of dynamic voltage scaling (DVS) policies are proposed and prove... Based on the fundamental relationship among the circuit power, the circuit delay and the supply voltage, four theorems associated with the application of dynamic voltage scaling (DVS) policies are proposed and proved. First, the existence characteristics of the optimal supply voltage for a single task are proved, which suggests that the optimal supply voltage for the single task should be selected only within a one-dimensional term, and the corresponding task end time by the optimal supply voltage should be identical with its deadline. Then, it is pointed out that the minimum energy consumption that the DVS policy can obtain when completing a single task is certainly lower than that of the dynamic power management (DPM) policy or the combined DVS+DPM policy under the same conditions. Finally, the theorem of energy consumption minimization for a multi-task group is proposed, which declares that it is necessary to keep the processor in the execution state during the whole task period to obtain the minimum energy consumption, while satisfying the deadline constraints of any task. 展开更多
关键词 dynamic voltage scaling dynamic power management circuit power circuit delay
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An Augmented Jacobian Method for Power Flow Analysis of Weakly Looped Distribution Systems with PV Buses
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作者 陈星莺 余昆 单渊达 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期216-220,共5页
A power flow analysis method for weakly looped distribution systems with PV buses is proposed in this paper. The proposed method is computationally more efficient and more robust compared with the conventional compens... A power flow analysis method for weakly looped distribution systems with PV buses is proposed in this paper. The proposed method is computationally more efficient and more robust compared with the conventional compensation methods. The robustness is achieved by embedding the boundary conditions of loops and PV buses into the Jacobian matrix. The computational efficiency is achieved by the carefully designed factorization of Jacobian matrix. Test results on a 33 bus system are presented. 展开更多
关键词 power flow radial distribution systems weakly loops PV bus
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Novel forward mode AC/AC converters with high frequency link 被引量:1
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作者 李磊 陈道炼 胡育文 《Journal of Southeast University(English Edition)》 EI CAS 2003年第3期246-249,共4页
A circuit configuration and a circuit topologic family of the novel forward mode AC/AC converters with high frequency link are presented. The circuit configuration is constituted of input cycloconverter, high frequenc... A circuit configuration and a circuit topologic family of the novel forward mode AC/AC converters with high frequency link are presented. The circuit configuration is constituted of input cycloconverter, high frequency transformer, output cycloconverter, input and output filters. The circuit topologic family includes eight circuit topologies, such as full-bridge-full-wave mode, etc. The bi-polarity phase-shifted control strategy and steady principles are thoroughly investigated. The output characteristics are obtained. By using the bi-polarity phase-shifted control strategy with phase-shifted control between the output cycloconveter and the input cycloconverter, commutation overlap period of the output cycloconverter, and polarity selection of the output filtering inductance current and the input voltage, the leakage inductance energy and the output filtering inductance current are naturally commutated, and surge voltage and surge current of the cycloconverters are overcome. The converters have such advantages as simple topology, two-stage power conversions(LFAC/HFAC/LFAC), bi-directional power flow, high frequency electrical isolation, good output waveforms, and strong ability to stabilize voltage. The converters lay key technical foundation on a new-type of regulated sinusoidal AC power supplies and electronic transformers. The correction and advancement of the converters are well verified by a principle test. 展开更多
关键词 forward mode high frequency link AC/AC converter bi-polarity phase-shifted control CYCLOCONVERTER
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A NOVEL AERONAUTICAL STATIC INVERTER WITH HIGH FREQUENCY PULSE DC LINK
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作者 陈道炼 刘志政 +1 位作者 严仰光 胡育文 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1999年第1期48-54,共7页
A new combined soft switching technique and a novel topology of aeronautical static inverter with high frequency pulse dc link are proposed in this paper, namely an electrical isolated converter can realize soft swi... A new combined soft switching technique and a novel topology of aeronautical static inverter with high frequency pulse dc link are proposed in this paper, namely an electrical isolated converter can realize soft switching of two stage cascade converters. It lays technical foundation for high power density, high efficiency and low cost aeronautical static inverter. The operation and design approach of this topology are carefully analyzed and studied. The validity of this topology is verified by simulation and test. 展开更多
关键词 INVERTERS high frequency links active clamp circuits combined soft switching techniques three state discrete pulse modulation
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Toward Energy-Efficient and Trustworthy eHealth Monitoring System 被引量:1
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作者 Ajmal Sawand Soufiene Djahel +1 位作者 Zonghua Zhang Farid Na?t-Abdesselam 《China Communications》 SCIE CSCD 2015年第1期46-65,共20页
The rapid technological convergence between Internet of Things (loT), Wireless Body Area Networks (WBANs) and cloud computing has made e-healthcare emerge as a promising application domain, which has significant p... The rapid technological convergence between Internet of Things (loT), Wireless Body Area Networks (WBANs) and cloud computing has made e-healthcare emerge as a promising application domain, which has significant potential to improve the quality of medical care. In particular, patient-centric health monitoring plays a vital role in e-healthcare service, involving a set of important operations ranging from medical data collection and aggregation, data transmission and segregation, to data analytics. This survey paper firstly presents an architectural framework to describe the entire monitoring life cycle and highlight the essential service components. More detailed discussions are then devoted to {/em data collection} at patient side, which we argue that it serves as fundamental basis in achieving robust, efficient, and secure health monitoring. Subsequently, a profound discussion of the security threats targeting eHealth monitoring systems is presented, and the major limitations of the existing solutions are analyzed and extensively discussed. Finally, a set of design challenges is identified in order to achieve high quality and secure patient-centric monitoring schemes, along with some potential solutions. 展开更多
关键词 eHealthcare wireless body area networks cyber physical systems mobile crowd sensing security privacy by design trust.
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Monitoring Seasonal Variations of Ionospheric TEC Using GPS Measurements 被引量:3
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作者 CAI Changsheng 《Geo-Spatial Information Science》 2007年第2期96-99,共4页
The regional ionospheric model is adopted to determine satellite-plus-receiver differential delay. The satellite-plus-receiver differential delay is estimated as constant values for each day. Dual-frequency GPS pseudo... The regional ionospheric model is adopted to determine satellite-plus-receiver differential delay. The satellite-plus-receiver differential delay is estimated as constant values for each day. Dual-frequency GPS pseudo-ranges observables are used to compute vertical TEC (VTEC). All the monthly mean VTEC profiles are represented by graphs using GPS data of the Beijing IGS site between 2000 and 2004. The monthly averaged values and amplitudes of VTEC are also represented by graphs. The results indicate that the VTEC has seasonal dependency. The monthly averaged values and amplitudes of VTEC in 2000 are about 2 times larger than that in 2004. The maximum VTEC values are observed in March and April, while the minimum VTEC values are observed in December. The seasonal variations trend is found to be similar after polynomial fitting between 2000 and 2004. 展开更多
关键词 GPS differential delay IONOSPHERE TEC
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Influences of collector DLZ on chalcopyrite and pyrite flotation 被引量:6
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作者 顾帼华 孙小俊 +1 位作者 李建华 胡岳华 《Journal of Central South University》 SCIE EI CAS 2010年第2期285-288,共4页
The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments,zeta potential measurements and infrared spectrum analysis.Flotation test r... The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments,zeta potential measurements and infrared spectrum analysis.Flotation test results indicate that DLZ is the selective collector of chalcopyrite.Especially,the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems,while the recovery of pyrite is less than 10%.When using CaO as pH regulator,at pH=7-11,the floatability of pyrite is depressed and the recovery is less than 5%.Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ,confirming that collector DLZ shows selectivity to chalcopyrite and pyrite.And FTIR results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface. 展开更多
关键词 CHALCOPYRITE PYRITE COLLECTOR FLOTATION zeta potential
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Energy Efficient Switch Policy for Small Cells 被引量:1
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作者 GAN Xiaoying WANG Luyang +4 位作者 FENG Xinxin LIU Jing YU Hui ZHANG Zhizhong LIU Haitao 《China Communications》 SCIE CSCD 2015年第1期78-88,共11页
Switch policy is essential for small cells to properly serve variable number of users in an energy efficient way.However,frequently switching small cell base stations(SBSs) may increase the network operating cost,espe... Switch policy is essential for small cells to properly serve variable number of users in an energy efficient way.However,frequently switching small cell base stations(SBSs) may increase the network operating cost,especially when there is an nonnegligible start-up energy cost.To this end,by observing the variety of user number,we focus on the design of a switch policy which minimize the cumulative energy consumption.A given user transmission rate is guaranteed and the capability of SBSs are limited as well.According to the knowledge on user number variety,we classify the energy consumption problem into two cases.In complete information case,to minimize the cumulative energy consumption,an offline solution is proposed according to critical segments.A heuristic algorithm for incomplete information case(HAIIC) is proposed by tracking the difference of cumulative energy consumption.The upper bound of the Energy Consumption Ratio(ECR) for HAIIC is derived as well.In addition,a practical Q-learning based probabilistic policy is proposed.Simulation results show that the proposed HAIIC algorithm is able to save energy efficiently. 展开更多
关键词 heterogeneous network small cell switch policy Q-LEARNING
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Optimization design of an electroabsorption modulator integrated with spot-size converter 被引量:1
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作者 HOU Lian-ping WANG Wei ZHU Hong-liang 《Optoelectronics Letters》 EI 2005年第2期83-87,共5页
A novel 1.55 μm spot-size converter integrated with electroabsorption modulator is designed and fabricated with conventional photolithography and chemical wet etching process.For the modulator,we employed a deeply-et... A novel 1.55 μm spot-size converter integrated with electroabsorption modulator is designed and fabricated with conventional photolithography and chemical wet etching process.For the modulator,we employed a deeply-etched ridge waveguide structure with polyimide on each side of its walls.For the spot-size converter,we employed a buried double-core structure in which a ridge-based passive waveguide is incorporated.The wide and thin passive waveguide is optically combined with a laterally tapered active waveguide to control the mode size.By simulation,the figure of merit is 4.17(dB/V/(100 μm)) and the beam divergence angles in the horizontal and vertical directions are as small as 11.2°×13.0°,respectively. 展开更多
关键词 优化设计 电吸收调节器 EAM 变流气 波导
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Neural adaptive PSD decoupling controller and its application in three-phase electrode adjusting system of submerged arc furnace 被引量:4
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作者 贺建军 刘郁乔 +1 位作者 喻寿益 桂卫华 《Journal of Central South University》 SCIE EI CAS 2013年第2期405-412,共8页
Taking three-phase electrode adjusting system of submerged arc furnace as study object which has nonlinear, time-variant, multivariable and strong coupling features, a neural adaptive PSD(proportion, sum and different... Taking three-phase electrode adjusting system of submerged arc furnace as study object which has nonlinear, time-variant, multivariable and strong coupling features, a neural adaptive PSD(proportion, sum and differential) dispersive decoupling controller was developed by combining neural adaptive PSD algorithm with dispersive decoupling network. In this work, the production technology process and control difficulties of submerged arc furnace were simply introduced, the necessity of establishing a neural adaptive PSD dispersive decoupling controller was discussed, the design method and the implementation steps of the controller are expounded in detail, and the block diagram of the controlled system is presented. By comparison with experimental results of the conventional PID controller and the adaptive PSD controller, the decoupling ability, adaptive ability, self-learning ability and robustness of the neural adaptive PSD dispersive decoupling controller have been testified effectively. The controller is applicable to the three-phase electrode adjusting system of submerged arc furnace, and it will play an important role for achieving the power balance of three-phrase electrodes, saving energy and reducing consumption in the process of smelting. 展开更多
关键词 PSD algorithm decoupling controller submerged arc furnace three phase electrode
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Integrated design of brushless motor drive and control system for robot joints 被引量:4
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作者 MO Shuai LI Xu +4 位作者 YANG Zhen-ning ZHOU Chang-peng GAO Han-jun CEN Guo-jian HUANG Yun-sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第12期3818-3828,共11页
To meet the requirements of high performance, low cost, and easy operation of the robot, a brushless motor drive and control system for the robot joint is designed, including CAN bus, WPF upper host computer developme... To meet the requirements of high performance, low cost, and easy operation of the robot, a brushless motor drive and control system for the robot joint is designed, including CAN bus, WPF upper host computer development, and magnetic encoders, and other sensors, in which the STM32 F103 chip is used as the main control chip, and the DRV8323 is a brushless motor drive chip. The principle of field-oriented control(FOC) brushless motor drive is elaborated.Meanwhile, the drive and control system design is completed from both hardware and software aspects. Finally, the PID algorithm is used for the closed-loop speed test of the robot joint. The experimental result shows that the designed robot joints and control system run smoothly and reliably, have the characteristics of modularization and miniaturization, and are suitable for the control of micro-service robots and manipulators. 展开更多
关键词 robot joint brushless motor control system upper computer
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Initial Pre-stress Finding and Structural Behaviors Analysis of Cable Net Based on Linear Adjustment Theory 被引量:4
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作者 任涛 陈务军 付功义 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第2期155-160,共6页
The tensile cable-strut structure is a self-equilibrate pre-stressed system.The initial pre-stress cal- culation is the fundamental structural analysis.A new numerical procedure was developed.The force density method ... The tensile cable-strut structure is a self-equilibrate pre-stressed system.The initial pre-stress cal- culation is the fundamental structural analysis.A new numerical procedure was developed.The force density method is the cornerstone of analytical formula,and then introduced into linear adjustment theory;the least square least norm solution,the optimized initial pre-stress,is yielded.The initial pre-stress and structural performances of a particular single-layer saddle-shaped cable-net structure were analyzed with the developed method,which is proved to be efficient and correct.The modal analyses were performed with respect to various pre-stress levels.Finally,the structural performances were investigated comprehensively. 展开更多
关键词 linear adjustment theory tensile cable-net structure initial pre-stress single-layer saddle-shaped cable net structural performances analysis
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Vector control of induction motor based on fractional-order intelligent-integral speed controller 被引量:2
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作者 MIAO Zhong-cui HAN Tian-liang +1 位作者 DANG Jian-wu JU Mei 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第2期125-133,共9页
To improve dynamic and static performances and robustness of the induction motor speed control system based on vector control,an improved fractional-order intelligent proportional integral(IPIλ)controller was applied... To improve dynamic and static performances and robustness of the induction motor speed control system based on vector control,an improved fractional-order intelligent proportional integral(IPIλ)controller was applied to the speed controller of the vector control system,which combined the intelligent fractional integral with the proportion according to the variation of deviation.Compared with proportional integral(PI)and fractional-order proportional integral(FOPI)controllers,the IPIλcontroller achieved better control performance.The stimulation results indicate that the IPIλcontroller can not only track the given speed quickly and accurately,but also have better anti-interference and robustness for load and parameters variations. 展开更多
关键词 fractional-order intelligent-integral induction motor speed controller
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A Distributed Cell Outage Compensation Mechanism Based on RS Power Adjustment in LTE Networks 被引量:2
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作者 LI Wenjing YU Peng YIN Mengjun MENG Luoming 《China Communications》 SCIE CSCD 2014年第A01期40-47,共8页
To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation managemen... To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation management mechanism. After detecting and analyzing the outage, a cell outage compensation algorithm based on reference signal power adjustment is proposed. The simulation results show that the proposed mechanism can mitigate the performance degradation significantly. Compared with other algorithms, the proposed scheme is more effective in compensating the coverage gap induced by cell outage 展开更多
关键词 LTE cell outage compensation (COC) reference signal power PSO
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