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Robust-augmentation nonlinear dynamic inversion control of over-actuated coaxial high-speed helicopter in transition mode

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Chinese Journal of Aeronautics 2024年第8期37卷 404-420页

作者： Yuqing QIU Yan LI Jinxi LANG Yuxian LIU zhong wang School of Automation Northwestern Polytechnical UniversityXi’an 710129China

As the elevator and rudder can be used actively for control,in addition to the rotors,Coaxial High-speed Helicopters(CHHs)have the problems of control redundancy and changing control authority in the transition *** paper presents a robust-augmentation transitioning flight control design for a CHH under the adverse conditions of parametric uncertainties and external ***,based on control characteristic analysis,an Adaptive Filtered Nonlinear Dynamic Inversion(AFNDI)controller is proposed for the angular rate to handle the effect of unknown unstructured uncertainties and external *** analysis proves that the presented angular rate controller can guarantee steady-state and transient ***,the attitude angle and velocity controllers are also ***,an Incremental-based Nonlinear Prioritizing Control Allocation(INPCA)method is designed to take into account control surface transition and changing control authority,which efficiently distributes the required moments between coaxial rotors and aero-surfaces,and avoids the control reversal problem of the yaw *** the proposed control architecture,the low-pass filter is introduced to alleviate the adverse influence of time delay and measurement ***,the effectiveness of the proposed controller is demonstrated through nonlinear numerical simulations,and is compared with existing *** results show that the proposed control law can improve both capabilities of disturbance rejection and fast response,and works satisfactorily for the CHH transitioning control characteristic.

关键词： Coaxial high-speed helicopter Transition mode Attitude control Control allocation Robust adaptive control

Temperature dependence of pyro-phototronic effect on self-powered ZnO/perovskite heterostructured photodetectors

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Nano Research 2016年第12期9卷 3695-3704页

作者： Wenbo Peng Ruomeng Yu Xingfu wang Zhaona wang Haiyang Zou Yongning He zhong Lin wang School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia 30332-0245 USA School of Electronic and Information Engineering Xi'an Jiaotong University Xi'an 710049 China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing 100083 China

Self-powered ZnO/perovskite heterostructured ultraviolet （UV） photodetectors （PDs） based on the pyro-phototronic effect have been recently reported as a promising solution for energy-efficient, ultrafast-response, and high-performance UV PDs. In this study, the temperature dependence of the pyro-phototronic effect on the photo-sensing performance of self-powered ZnO/perovskite heterostructured PDs was investigated. The current responses of these PDs to UV light were enhanced by 174.1% at 77 K and 28.7% at 300 K owing to the improved pyro-phototronic effect at low temperatures. The fundamentals of the pyro-phototronic effect were thoroughly studied by analyzing the charge- transfer process and the time constant of the current response of the PDs upon UV illumination. This work presents in-depth understandings about the pyro- phototronic effect on the ZnO/perovskite heterostructure and provides guidance for the design and development of corresponding optoelectronics for ultrafast photo sensing, optothermal detection, and biocompatible optoelectronic probes.

关键词： self-powered ZnO perovskite pyro-phototronic effect temperature dependence

Three-dimensional graphene and its composite for gas sensors

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Rare Metals 2021年第6期40卷 1494-1514页

作者： Meng Hao Wen Zeng Yan-Qiong Li zhong-Chang wang College of Materials Science and Engineering Chongqing UniversityChongqing 400030China School of Electronic and Electrical Engineering Chongqing University of Arts and SciencesChongqing 400030China International Iberian Nanotechnology Laboratory(INL) Avenida Mestre Jose VeigaBraga 4715-330Portugal

As a two-dimensional(2D)material,graphene shows excellent advantages in the field of gas sensors due to its inherent large specific surface area and unique electrical ***,in the practical application of gas detection,graphene sheet is easy to form irreversible agglomeration and has some limitations such as low sensitivity,long response time and slow recovery speed,which greatly reduce its gas sensing *** a gas sensing material,three-dimensional(3D)porous graphene has been extensively studied in recent years owing to its larger specific surface area and stable *** order to synthesize graphene with different three-dimensional structures,many methods have been ***,the synthesis and assembly of three-dimensional graphene and its composites were reviewed,with emphasis on the application of three-dimensional graphene and its composites in the field of gas *** challenges and development prospects of three-dimensional graphene materials in the application of gas sensors were briefly described.

关键词： Three-dimensional graphene Gas sensor Sensitivity Composites material

Influence of non-iso-velocity casting on flow-field index of a 41-ton six-strand Tundish by physical and numerical modeling

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Journal of Iron and Steel Research International 2023年第1期30卷 51-63页

作者： Hang-hang Zhu Min wang Cheng Yao zhong-liang wang Xiao-liang wang Yan-ping Bao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Technical Support Center for Prevention and Control of Disastrous Accidents in Metal Smelting Beijing 100083China Fengbao Special Steel Co. Ltd.Linzhou 456552HenanChina

The flow-field index in a 41-ton six-strand tundish is considered through adjusting the ratio of the casting velocity between the strands to eliminate the negative impact of iso-velocity casting in multi-strand tundish on the consistency of each strand due to the large ratio of length to width with narrow shape structure,resulting in poor consistency of each *** particular,the response time of strand-1 and strand-6 is relatively long,which affects the uniformity of the temperature field and flow field of the entire *** the basis of verifying that the error between the numerical simulations and hydraulic experiments is less than 6%,six cases with the casting velocity ratio changing from 0.8 to 1.3(with an interval of 0.1)are considered by calculation of numerical *** is concluded that the consistency of each flow can be obviously improved by increasing the casting velocity ratio between side-strand and *** increasing the casting velocity ratio,the flow field in the tundish became much active,the temperature field presented well uniformity,and the tracer concentration distribution in local dead zones was improved.

关键词： Six-strand tundish Non-iso-velocity casting Casting velocity ratio Residence time distribution curve Tracer concentration

Catalytic oxidation of vinyl chloride over Co-Ce composite oxides derived from ZIF-67 template:Effect of cerium incorporation

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Journal of Rare Earths 2023年第6期41卷 870-880,I0003页

作者： Hongliang Zhang Shuoming wang Mingju wang Guanghao Li Lihang Yu Xuehua Liu zhong wang Chuanhui Zhang Institute of Materials for Energy and Environment College of Materials Science and EngineeringQingdao UniversityQingdao 266071China Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China

Transition metal oxides are regarded as an economical and efficient catalytic alternate for catalytic oxidation of volatile organic compounds(VOCs)*** morphological decoration and the incorporation of extrinsic metals were demonstrated to be effective strategies for achieving noticeable catalytic *** this work,a novel Co-Ce composite oxides catalyst was obtained by the pyrolysis of ZIF-67 template with the impregnation of certain cerium cations(denoted as ZIF-CoCe).Compared with the reference Co-Ce composite oxides by the sol-gel(denoted as SG-CoCe)and physical mixing(denoted as MIX-CoCe)methods,ZIF-CoCe delivers significantly higher catalytic activity for vinyl chloride oxidation,which are demonstrated to be closely related with its superior redox capacity,more abundance of surface active Co^(3+)sites and adsorbed active oxygen species from oxygen *** addition,the unique cage-like morphological feature of the Co-based catalysts derived from ZIF-67 template plays a crucial function in kinetically facilitating the mass transfer of catalytic reaction and promoting the catalytic VC oxidation *** regard to in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTs)analysis,enol and carboxylic acid species are identified to be the key organic intermediates during catalytic vinyl chloride oxidation.

关键词： Rare earth Catalytic oxidation Cerium incorporation Redox behavior Surface oxygen species

SYNERGISTIC EFFECTS OF NOVOLAC-BASED CHAR FORMER WITH A PHOSPHORUS/NITROGEN-CONTAINING FLAME RETARD ANT IN POLYAMIDE 6

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Chinese Journal of Polymer Science 2012年第1期30卷 72-81页

作者： Wei-cheng Xiong Li Chen De-yi wang Fei Song Yu-zhong wang Center for Degradation an-d Flame--Retardant Polymeric Materials College of-Chemistry State Key Laboratory of Polymer Materials Engineering National Engineering Laboratory of Eco-Friendly Polymeric Materials （Sichuan） Sichuan University Chengdu 610064 China

The synergistic effect of phosphorus oxynitride（PON） with a novolac-based char former modified by salification （NA-metal salt） on the flame retardance of polyamide 6（PA6） was *** this purpose,various flame-retardant PA6 systems were melt-compounded with PON,PON/NA,PON/NA-V_2O_5 and PON/NA-Fe_2O_3,and their flame retardance was evaluated by measuring the limiting oxygen index（LOI） values and UL-94 vertical burning *** results showed that,compared with the PA6/PON/NA system,the combination of two char formers（NA-V_2O_5,NA-Fe_2O_3） with PON could obviously improve the char formation and flame retardance of *** flame retardance and cone calorimetric analyses showed the stronger synergism as well as the better flame retardant performance of PON/NA-Fe_2O_3 flame retardant system. The effects of different char formers on the flame retardance and thermal stability of this system were also discussed.

关键词： Polyamide Flame retardance Novolac resin Synergistic effect

Preparation of anionically polymerized butadiene-co-styrene copolymer-multiwalled carbon nanotubes nanocomposites

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Chinese Chemical Letters 2012年第10期23卷 1205-1208页

作者： zhong Guang wang Jing Hua Ling Xu Key Laboratory of Rubber-Plastics Ministry of Education Qingdao University of Science and TechnologyQingdao 266042China

Poly（butadiene-co-styrene） copolymer/multi-walled carbon nanotubes （SB-MWNTs） nanocomposites are prepared via termi- nating anionically synthesized living poly（butadiene-styryl）lithium with acyl chlorides on the MWNTs, which obtained from the carboxylation and acylation of the MWNTs. Results from the characterization of the SB-MWNTs nanocomposites, including its soluble in solvent, UV-vis and TEM of the dissolved samples, TGA and SEM of nanocomposites are presented and discussed respectively. MWNTs treated by SB can be easily distributed in the SBR （styrene-butadiene rubber） matrix.

关键词： Carbon nanotubes Styrene Butadiene Anionically

Left-definite boundary conditions of Sturm-Liouville problems when the interval shrinks to a point

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Applied Mathematics(A Journal of Chinese Universities) 2011年第1期26卷 29-37页

作者： GAO Yun-lan wang zhong WU Hong-you Department of Mathematics Inner Mongolia University of Technology Huhhot 010051 China Department of Mathematics ZhaoQing University Zhaoqing 526061 China Department of Mathematics Northern Illinois University DeKalb IL60115 USA

On the condition that the interval of the problem shrinks to a point, we investigated the separated boundary conditions Sα,β of left-definite Sturm-Liouville problem, and answered the following question： Is there a co ∈ J such that Sα,β is always left-definite or semi-left-definite for the Sturm-Liouville equation for each c ∈ （a, co）？

关键词： Left-definite Sturm-Liouville problem semi-left-definite Sturm-Liouville problem separatedboundary condition.

Testing Serial Correlation in Semiparametric Varying-Coefficient Partially Linear EV Models

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Acta Mathematicae Applicatae Sinica 2008年第1期24卷 99-116页

作者： Xue-mei Hu Zhi-zhong wang Feng Liu School of Mathematics and Computing Technology Central South University Changsha 410075 China School of Mathematics and Physics Chongqing Institute of Technology Chongqing 400050 China

This paper studies estimation and serial correlation test of a semiparametric varying-coefficient partially linear EV model of the form Y = X^Tβ ＋Z^Tα（T）＋ε,ξ = X ＋ η with the identifying condition E[（ε,η^T）^T] =0, Cov[（ε,η^T）^T] = σ^2Ip＋1. The estimators of interested regression parameters /3 , and the model error variance σ2, as well as the nonparametric components α（T）, are constructed. Under some regular conditions, we show that the estimators of the unknown vector β and the unknown parameter σ2 are strongly consistent and asymptotically normal and that the estimator of α（T） achieves the optimal strong convergence rate of the usual nonparametric regression. Based on these estimators and asymptotic properties, we propose the VN,p test statistic and empirical log-likelihood ratio statistic for testing serial correlation in the model. The proposed statistics are shown to have asymptotic normal or chi-square distributions under the null hypothesis of no serial correlation. Some simulation studies are conducted to illustrate the finite sample performance of the proposed tests.

关键词： Varying-coefficient model partial linear EV model the generalized least squares estimation serial correlation empirical likelihood