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Synthesis and properties of novel thermotropic liquid crystalline copoly(ester-imide)s

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Chinese Chemical Letters 2009年第12期20卷 1510-1513页

作者： Guo yao yi Gu State Key Laboratory of Polymer Materials Engineering of China College of Polymer Science and Engineering Sichuan University Chengdu 610065 China

Four novel copoly（ester-imide）s based on 3,3′,4,4′-biphenyltetracarboxylic dianhydride, bis（trimellitic acid anhydride） phenyl ester and di-p-aminophenyl ester of dicarboxylic acids were synthesized via two-step method in order to investigate whether two imide mesogenic units with different conformation and polarity could control the formation of LC-phase. Polarizes light microscopy （PLM） and differential scanning calorimetry （DSC） have shown that three polymers formed the nematic phase with ＂thread schlieren texture＂ and a polymer formed the nematic phase with ＂Inversion walls texture＂.

关键词： Copoly(ester-imide) Inversion walls texture Mesogenic unit Thermotropic liquid crystalline

Is playing-as-downloading feasible in an eMule P2P file sharing system?

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第6期11卷 465-475页

作者： Wen-yi WANG yao-wu CHEN Advanced Digital Technology and lnstruments Institute Zhejiang University Hangzhou 310027 China

Peer-to-peer(P2P) swarm technologies have been shown to be very efficient for large scale content distribution systems, such as the well-known BitTorrent and eMule ***, these systems have been designed for generic file sharing with little consideration of media streaming support, and the user cannot start a movie playback before it is completely *** playing-as-downloading capability would be particularly useful for a downloading peer to evaluate if a movie is valuable to be downloaded, and it could also help the P2P content distribution system to locate and eliminate the polluted *** this paper we address this issue by introducing a new algorithm, wish driven chunk distribution(WDCD), which enables the P2P file sharing system to support the video-on-demand(VOD) function while keeping the P2P native downloading speed.A new parameter named next-play-frequency is added to the content chunk to strike a replication balance between downloading and streaming *** modify the eMule as the test bed by adding the WDCD algorithm and then verify the prototype implementation by *** experimental results show that the proposed algorithm can keep the high downloading throughput performance of the eMule system with a good playing-as-downloading function.

关键词： Peer-to-peer(P2P) Video-on-demand(VOD) Playing-as-downloading eMule

A Quick Calculation Method for Radiation Pattern of Submillimeter Telescope with Deformation and Displacement

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Research in Astronomy and Astrophysics 2024年第3期24卷 249-265页

作者： Jia You yi-Wei yao Zheng Wang School of Automation Southeast UniversityNanjing 210096China

Radiation pattern captures the electromagnetic performance of reflector antennas,which is significantly affected by the deformation of the primary reflector due to gravity and the displacement of the secondary *** the design process of large reflector antennas,a substantial amount of time is often dedicated to iteratively adjusting structural parameters and validating electromagnetic *** improve the efficiency of the design process,we first propose an approximate calculation method of optical path difference(OPD)for the deformation of the primary reflector under gravity and the displacement of the secondary *** an OPD fitting function based on the modified Zernike polynomials is proposed to capture the phase difference of radiation over the aperture plane,based on which the radiation pattern will be obtained quickly by the aperture field integration *** experiments demonstrate the effectiveness of the proposed quick calculation method for analyzing the radiation pattern of a 10.4 m submillimeter telescope antenna at its highest operating frequency of 856 *** comparison with the numerical simulation method based on GRASP(which is an antenna electromagnetic analysis tool combining physical optics(PO)and physical theory of diffraction(PTD)),the quick calculation method reduces the time for radiation pattern analysis from more than one hour to less than two ***,the quick calculation method exhibits excellent accuracy for the figure of merit(FOM)of the radiation ***,the proposed quick calculation method can obtain the radiation pattern with high speed and *** to the time-consuming numerical simulation method(PO and PTD),it can be employed for quick analysis of the radiation pattern for the lateral displacement of the secondary reflector and the deformation of the primary reflector under gravity in the design process of a reflector antenna.

关键词： instrumentation high angular resolution-methods data analysis-methods analytical

Polymer translocation through nanopore under external electric field:dissipative particle dynamics study

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Applied Mathematics and Mechanics(English Edition) 2015年第12期36卷 1581-1592页

作者： Jinglin MAO yi yao Zhewei ZHOU Guohui HU Shanghai Institute of Applied Mathematics and Mechanics College of Sciences Shanghai University Shanghai Key Laboratory of Mechanics in Energy Engineering

The DNA sequencing technology has achieved a leapfrog development in recent years. As a new generation of the DNA sequencing technology, nanopore sequenc- ing has shown a broad application prospect and attracted vast research interests since it was proposed. In the present study, the dynamics of the electric-driven translocation of a homopolymer through a nanopore is investigated by the dissipative particle dynam- ics （DPD）, in which the homopolymer is modeled as a worm-like chain （WLC）. The DPD simulations show that the polymer chain undergoes conformation changes during the translocation process. The different structures of the polymer in the translocation process, i.e., single-file, double folded, and partially folded, and the induced current block- ades are analyzed. It is found that the current blockades have different magnitudes due to the polymer molecules traversing the pore with different folding conformations. The nanoscale vortices caused by the concentration polarization layers （CPLs） in the vicinity of the sheet are also studied. The results indicate that the translocation of the polymer has the effect of eliminating the vortices in the polyelectrolyte solution. These findings are expected to provide the theoretical guide for improving the nanopore sequencing tech- nique.

关键词： nanopore sequencing technology electric-driven translocation dissipative particle dynamics (DPD)

Multiconditional machining process quality prediction using deep transfer learning network

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Advances in Manufacturing 2023年第2期11卷 329-341页

作者： Bo-Hao Li Li-Ping Zhao yi-Yong yao State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong UniversityXi'an710049People's Republic of China School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an710049People's Republic of China

The quality prediction of machining processes is essential for maintaining process stability and improving component quality. The prediction accuracy of conventional methods relies on a significant amount of process signals under the same operating conditions. However, obtaining sufficient data during the machining process is difficult under most operating conditions, and conventional prediction methods require a certain amount of training data. Herein, a new multiconditional machining quality prediction model based on a deep transfer learning network is proposed. A process quality prediction model is built under multiple operating conditions. A deep convolutional neural network (CNN) is used to investigate the connections between multidimensional process signals and quality under source operating conditions. Three strategies, namely structure transfer, parameter transfer, and weight transfer, are used to transfer the trained CNN network to the target operating conditions. The machining quality prediction model predicts the machining quality of the target operating conditions using limited data. A multiconditional forging process is designed to validate the effectiveness of the proposed method. Compared with other data-driven methods, the proposed deep transfer learning network offers enhanced performance in terms of prediction accuracy under different conditions.

关键词： Multiconditional machining process Intelligent manufacturing Deep transfer learning Quality prediction Process stability

A novel predict-prevention quality control method of multi-stage manufacturing process towards zero defect manufacturing

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Advances in Manufacturing 2023年第2期11卷 280-294页

作者： Li-Ping Zhao Bo-Hao Li yi-Yong yao State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong UniversityXi'an710049People's Republic of China School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an710049People's Republic of China

Zero defection manufacturing (ZDM) is the pursuit of the manufacturing industry. However, there is a lack of the implementation method of ZDM in the multi-stage manufacturing process (MMP). Implementing ZDM and controlling product quality in MMP remains an urgent problem in intelligent manufacturing. A novel predict-prevention quality control method in MMP towards ZDM is proposed, including quality characteristics monitoring, key quality characteristics prediction, and assembly quality optimization. The stability of the quality characteristics is detected by analyzing the distribution of quality characteristics. By considering the correlations between different quality characteristics, a deep supervised long-short term memory (SLSTM) prediction network is built for time series prediction of quality characteristics. A long-short term memory-genetic algorithm (LSTM-GA) network is proposed to optimize the assembly quality. By utilizing the proposed quality control method in MMP, unqualified products can be avoided, and ZDM of MMP is implemented. Extensive empirical evaluations on the MMP of compressors validate the applicability and practicability of the proposed method.

关键词： Zero defection manufacturing(ZDM) Multi-stage manufacturing process(MMP) Moving window Deep supervised long-short term memory(SLSTM)network Assembly quality optimization

Cross-Polarized Single Photon Emission from Single Semiconductor Quantum Dots with V-Type Level Driven by Pulse Field

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Communications in Theoretical Physics 2008年第12期50卷 1417-1421页

作者： LIU Wen-Juan LI yao-yi School of Science Hunan University of Technology Zhuzhou 412008 China Department of Physics Wuhan University Wuhan 430072 China State Key Laboratory for Surface Physics Institute of Physics the Chinese Academy of Sciences Beijing 100080 China

The statistic properties of photon emissions from single semiconductor quantum dots with V-type leveldriven by pulses are investigated *** on quantum regression theorem and master equations,the dynamicequations of the second-order correlation function of the photon emissions are *** calculated results reveal thatthe efficiency of single photon emissions from two orthogonal polarization eigenstates(|x〉and |y〉)reaches the maximumwhen the input pulses area is about π,and the probability of the cross-polarized single photon emission from |x〉and |y〉decreases with increasing of pulse width.

关键词： semiconductor quantum dots cross-polarized single photon emission V-type system

Computational Intelligence Prediction Model Integrating Empirical Mode Decomposition,Principal Component Analysis,and Weighted k-Nearest Neighbor

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Journal of Electronic Science and Technology 2020年第4期18卷 341-349页

作者： Li Tang He-Ping Pan yi-Yong yao School of Management and Economics University of Electronic Science and Technology of ChinaChengdu 611731 Tianfu College Southwestern University of Finance and EconomicsChengdu 610052 Intelligent Finance Research Center Chongqing Institute of FinanceChongqing 400067

On the basis of machine leaning,suitable algorithms can make advanced time series *** paper proposes a complex k-nearest neighbor(KNN)model for predicting financial time *** model uses a complex feature extraction process integrating a forward rolling empirical mode decomposition(EMD)for financial time series signal analysis and principal component analysis(PCA)for the dimension *** information-rich features are extracted then input to a weighted KNN classifier where the features are weighted with PCA ***,prediction is generated via regression on the selected nearest *** structure of the model as a whole is *** test results on real historical data sets confirm the effectiveness of the models for predicting the Chinese stock index,an individual stock,and the EUR/USD exchange rate.

关键词： Empirical mode decomposition(EMD) k-nearest neighbor(KNN) principal component analysis(PCA) time series

Collaborative Simulation of Mechanical Structure and Control Systems of Leighton Chajnantor Telescope

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Research in Astronomy and Astrophysics 2023年第4期23卷 133-147页

作者： yi-Wei yao Wei-Rui Chen Zheng Wang School of Automation Southeast UniversityNanjing 210096China

Leighton Chajnantor Telescope(LCT)will be moved from the summit of Maunakea,Hawaii to Chajnantor Plateau,Chile and be refurbished *** wind disturbance at the new site will bring great challenges to the servo control of *** is necessary and important to develop a simulation platform that behaves as close as possible to the real telescope for testing the performance of the designed servo *** this paper,a collaborative simulation platform of LCT based on Adams and Matlab/Simulink is *** this platform,the mechanical structure model of LCT can be integrated with its control system model such that a collaborative simulation of the mechanical structure and the control system of LCT can be *** mechanical structure model of LCT,which contains both rigid body models(i.e.,the mount)and flexible body models(i.e.,the primary reflector),is developed by using *** servo system model and the wind disturbance model are constructed by using Matlab/*** conducting collaborative simulation,the performances of the servo controller based on the rigid body model and the rigid-flexible coupling model of LCT are *** comparison shows that the controller designed based on the rigid body model does not perform well when it is employed to control the rigid-flexible coupling model of ***,by readjusting parameters of the servo controller,its performance can be further improved when applied to the rigid-flexible coupling ***,an LCT model of integrated mechanical structure and control systems is very helpful for analyzing its performance more accurately and designing a better servo controller.

关键词： telescopes-submillimeter general-techniques miscellaneous