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Footprint Problem with Angle of Attack Optimization for High lifting Reentry Vehicle

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Chinese Journal of Aeronautics 2012年第2期25卷 243-251页

作者： li Huifeng ZHANG Ran li zhaoying ZHANG Rui School of Astronautics Beihang UniversityBeijing 100191China

A formal analysis to footprint problem with effects of angle of attack （AOA） is presented. First a flexible and rapid standardized method for footprint generation is developed. Zero bank angle control strategy and the maximum crossrange method are used to obtain virtual target set; afterward, closed-loop bank angle guidance law is used to find footprint by solving closest approach problem for each element in virtual target set. Then based on quasi-equilibrium glide condition, the typical inequality reentry trajectory constraints are converted to angle of attack lower boundary constraint. Constrained by the lower boundary, an original and practical angle of attack parametric method is proposed. By using parametric angle of attack profile, optimization algorithm for angle of attack is designed and the impact of angle of attack to footprint is discussed. Simulations with different angle of attack profiles are presented to demonstrate the performance of the proposed footprint solution method and validity of optimal algorithm.

关键词： reentry angle of attack optimization footprint trajectory constraints bank angle control

Comparative study on pyrolysis of bamboo in microwave pyrolysis-reforming reaction by binary compound impregnation and chemical liquid deposition modified HZSM-5

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Journal of Environmental Sciences 2020年第8期32卷 186-196页

作者： Haoran Du Zhaoping Zhong Bo Zhang Kun Shi zhaoying li Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education Southeast UniversityJiangsu 210096China

The deactivation of catalyst is a significant reason for its limited application during the catalytic fast pyrolysis(CFP)*** reduce the coke formation,binary compound impregnation(BCI)and chemical liquid deposition(CLD)were used to modify HZSM-5 *** the same time,the self-designed microwave reactor separated the pyrolysis of bamboo and catalytic upgrading of primary vapor,which made the catalytic effect more *** results indicated that CLD used TiO 2 deposition to cover external acid sites,while BCI by phosphorus-nickel could cover and partly destroy superficial acid sites through two different *** the scope of the loaded amount studied,the yield of aromatic hydrocarbons in the oil phase increased at first and then decreased,while the coke formation reduced ***(benzene,toluene and xylene),the most valuable product in bio-oil,drastically increased by 39.1%and 22.6%respectively over the CLD and BCI modified *** the catalytic performance as well as cost,CLD over HZSM-5 has more advantages in the CFP process to upgrade bio-oil.

关键词： Bamboo Modified HZSM-5 Microwave Binary compound impregnation Chemical liquid deposition

Lane departure warning systems and lane line detection methods based on image processing and semantic segmentation:A review

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第6期7卷 748-774页

作者： Weiwei Chen Weixing Wang Kevin Wang zhaoying li Huan li Sheng liu School of Information Engineering Chang’an UniversityXi'an 710064China Xi’an Aeronautical Polytechnic Institute Xi'an 710089China Royal Institute of Technology Stockholm 10044Sweden Audible Inc. NewarkNJ 07102USA School of Computer Science and Engineering Xi’an University of TechnologyXi'an 710048China

Recently,the development and application of lane line departure warning systems have been in the *** any of the systems,the key part of lane line tracking,lane line identification,or lane line departure warning is whether it can accurately and quickly detect lane *** 1990 s,they have been studied and implemented for the situations defined by the good viewing conditions and the clear lane markings on *** then,the accuracy for particular situations,the robustness for a wide range of scenarios,time efficiency and integration into higher-order tasks define visual lane line detection and tracking as a continuing research *** present,these kinds of lane marking line detection methods based on machine vision and image processing can be divided into two categories:the traditional image processing and semantic segmentation(includes deep learning)*** former mainly involves feature-based and model-based steps,and which can be classified into similarity-and discontinuity-based ones;and the model-based step includes different parametric straight line,curve or pattern *** semantic segmentation includes different machine learning,neural network and deep learning methods,which is the new trend for the research and application of lane line departure warning *** paper describes and analyzes the lane line departure warning systems,image processing algorithms and semantic segmentation methods for lane line detection.

关键词： Traffic engineering Lane departure warning Lane line detection Image processing Image analysis Semantic segmentation

Synthetic process and spark plasma sintering of SrIrO_(3) composite oxide

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Journal of Advanced Ceramics 2013年第4期2卷 347-352页

作者： Yongshang TIAN Yansheng GONG zhaoying li Feng JIANG Hongyun JIN Faculty of Material Science and Chemistry China University of GeosciencesWuhan 430074People’s Republic of China Engineering Research Center and Application of Nano-Geomaterials of Ministry of Education China University of GeosciencesWuhan 430074People’s Republic of China

Single phase of SrIrO_(3) powders and ceramics were obtained by solid-state chemical reaction method and spark plasma sintering(SPS)technique,*** evolutions,characteristics,morphology and resistivity of the samples were studied by using thermogravimetric analysis-differential scanning calorimetry(TG-DSC),X-ray diffractometry(XRD),field emission scanning electron microscopy(FESEM)and four-point probe method,*** results showed that the reaction process to form SrIrO_(3) phase occurred between SrCO_(3) and IrO_(2) directly during the heating *** using optimum fabrication conditions established from the TG-DSC results,single phase of SrIrO_(3) powders was synthesized at 800-1000℃.SrIrO_(3) ceramics were sintered by SPS technique at 1000-1100℃with a pressure of 30 MPa,showing a high relative density of 92%-96%and dense *** room-temperature resistivity of SrIrO_(3) ceramics was about 2×10^(-4)Ω×*** present study can provide high-quality ceramic target for the preparation of SrIrO_(3) films in traditional physical vapor deposition(PVD)method.

关键词： SrIrO_(3) powder controllable synthesis spark plasma sintering(SPS)

Adaptive Proportion Navigation Guidance for Vehicle Terminal Flight

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Adaptive Proportion Navigation Guidance for Vehicle Terminal...

Robust Mode Transition Attitude Control of Tail-Sitter Unmanned Aerial Vehicles 36

第25届中国控制与决策会议

作者： li zhaoying Zhang Ran li Huifeng School of Astronautics Beihang University

ISBN: (纸本)9781467355322

The guidance system of terminal flight is to guide the vehicle flies into the target precisely in a specific direction while satisfy all the constraints. A new adaptive proportion navigation guidance method is proposed. First the constraints are analyzed. To provide enough time for the lateral and longitudinal adjustments, a convergence strategy is designed and it improves the performance of proportion navigation guidance greatly. By considering the dynamics of vehicle, the execute errors of guidance commands are eliminated with an on-line navigation constants adaptive law. The angle rates of flight path angle and heading angle are converted into angle of attack and bank angle commands through command allocation. The simulation results show that the proposed terminal guidance method is precise and reliable.

关键词： Proportion Navigation Guidance Terminal Flight Constraints Commands Allocation

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Robust Mode Transition Attitude Control of Tail-Sitter Unman...

RESEARCH OF MICRO ELECTRO DISCHARGE MACHINING EQUIPMENT AND PROCESS TECHNIQUES

第36届中国控制会议

作者： liU Deyuan liU Hao li zhaoying School of Astronautics Beihang Univeristy

ISBN: (纸本)9781538629185

In this paper, an attitude control strategy is proposed for a class of tail-sitter aerial vehicles, which is required to achieve the desired tracking control performance during the mode transition. The resulted controller is constructed by a nominal controller and a robust compensator to reduce the effects of nonlinear dynamics and uncertainties. Theoretical analysis and numerical simulation results are given to show the effectiveness of the constructed closed-loop control system.

关键词： Tail-sitter aerial vehicle robust control nonlinear system uncertain system

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Chinese Journal of Mechanical Engineering 2002年第2期15卷 177-181页

作者： li Yong Guo Min li Fang Zhou zhaoying Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084, China Department of Precision Instruments and Mechanology Tsinghua University 北京 100084

Micro electro discharge machining (micro EDM) is a feasible way tomanufacture micro structures and has potential application in advanced industrial fields. For therealization of micro EDM, it is necessary to pay careful attention to its equipment design and thedevelopment of process techniques. The present status of research and development of micro EDMequipment and process techniques is overviewed. A micro electro discharge machine incorporated withan inchworm type of micro feed mechanism is introduced, and a micro electro discharge machine fordrilling micro holes suitable to industrial use is also introduced. Some of the machiningexperiments carried out on the micro EDM prototypes are shown and the feasibility of the micro EDMtechnology to practical use is discussed.

关键词： Micro electro discharge machining Inchworm mechanism Friction drivemechanism Micro electrode Micro hole Micro structure

Robust attitude control for a tail-sitter aircraft 36

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Robust attitude control for a tail-sitter aircraft

Cloning and Sequence Analysis of Carbonic Anhydrase-related Protein 10-like in Apis mellifera

第36届中国控制会议

作者： lixin Zhang zhaoying li Hao liu Chao Wang School of Astronautics Beihang University

ISBN: (纸本)9781538629185

Many challenges of modeling and control exist in the tail-sitter aircraft,including parameter uncertainty,highly coupling,nonlinearity,and external *** this paper,the model of a tail-sitter aircraft is simplified at the nominal condition to obtain the nominal linear invariant *** a robust controller based on the H control theory is proposed to deal with the attitude tracking control problem and decrease the effects of multiple *** is proved that the closed-loop system has robust stability,and the tracking error can converge to *** is shown that the proposed robust controller can maintain the attitude angle adjustment accuracy and robustness to the model uncertainty and external disturbance.

关键词： Tail-sitter aircraft attitude dynamics robust control

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Agricultural Biotechnology 2012年第4期1卷 46-48,53页

作者： zhaoying li Department of Biological Science and Technology Shaanxi Institute of Education

[ Objective ] This study aimed to clone and analyze the gene sequence encoding carbonic anhydrase-related protein lO-like （ CARP X） from Apis mellif era. [Method] The cDNA sequence of CARPX gene was cloned through RT-PCR, and then analyzed with bioinformatic method. [Result] The full-length cDNA sequence of CARPX was 972 bp long and encoded 324 amino acid residues, including a signal peptide and two transmembrane domains. The predicted molecular mass was 37.1 kDa and the predicted isoeleetric point was 7.458. The CARP X from A. mellifera shared close relationship with proteins from Apisflorae, Bombtas impatiens, Bombus terrestris, Nasonia vitripennis and Acyrthosiphon pisum. The insect CARP X family may include two subfamilies. [ Conclusion] The results pro- vide basis for studying CARPs family.

关键词： Apis mellifera CARP X gene Cloning Sequence analysis Protein structure