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Modulation of Conformational Transition of Polypeptides under Slightly Acidic Environment

Chinese Journal of Chemistry 2022年第24期40卷 2981-2987,I0002页

作者： Jie Li Jiajie Zhang qi Long Weisheng Guo Menghua xiong Guangzhou First People's Hospital School of Biomedical Sciences and EngineeringSouth China University of TechnologyGuangzhou International CampusGuangzhouGuangdong511442 China National Engineering Research Center for Tissue Restoration and Reconstruction South China University of TechnologyGuangzhouGuangdong510006 China Translational Medicine Center Key Laboratory of Molecular TargetClinical PharmacologySchool of Pharmaceutical SciencesThe Second Affiliated HospitalGuangzhou Medical UniversityGuangzhouGuangdong510260 China Key Laboratory of Biomedical Engineering of Guangdong Province and Innovation Center for Tissue Restoration and ReconstructionSouth China University of TechnologyGuangzhouGuangdong510006 China Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education South China University of TechnologyGuangzhouGuangdong510006 China

Controlling the conformational transition of polypeptides under slightly acidic environment is ***,we report a class of pH-responsive helix-to-coil conformationally transitionable polypeptides(pCTPs)by simply conjugating tertiary amine groups(TAs)to *** conformation is highly dependent on the charge state of TAs,showing a helical structure when most TAs are deprotonated and a non-helical structure when majority of TAs are *** conformational transition pH can be modulated by tuning the hydrophobicity of TAs and the incorporation of hydrophobic monomers at a pH range of 7.2 to *** pCTP showed a vesicle-to-micelle transition when their conformation transformed from helix to coil,facilitating controlled drug *** study provided an approach to control the conformational transition of polypeptides under slightly acidic condition.

关键词： Peptides Conformational transition Helical structures pH responsiveness Drug delivery

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Accurate attitude estimation of HB2 standard model based on QNCF in hypersonic wind tunnel test

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Chinese Journal of Aeronautics 2020年第1期33卷 64-72页

作者： Haotian YANG Bin ZHOU qi WEI xiong WANG Xiaobin XU Rong ZHANG Department of Precision Instrument Tsinghua UniversityBeijing 100084China Xi’an Research Institute of High Technology Xi’an 710025China Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China

The accuracy of the HB2 standard model attitude measurement has an important impact on the hypersonic wind tunnel data *** limited size of the model and the existence of external vibrations make it challenging to obtain real-time reliable attitude *** reduce the influence of attitude errors on test results,this paper proposes a Quaternion Nonlinear Complementary Filter(QNCF)attitude determination algorithm based on Microelectromechanical Inertial Measurement Unit(MEMS-IMU).Firstly,the threshold-based PI control strategy is adopted to eliminate noise effect according to the Acceleration Magnitude Detector(AMD).Then,the flexible quaternion method is updated to carry out attitude estimation which is operational and easy to be embedded in the Field Programmable Gate Array(FPGA).Finally,a high-precision three-axis turntable test and a hypersonic wind tunnel test are *** results show that the pitchroll attitude errors are within 0.05°and 0.08°in the high-precision three-axis turntable test in a calculation time of 100 s respectively,and the attitude error is within 0.3°after the elastic angle correction in the hypersonic wind tunnel *** proposed method can provide accurate real-time attitude reference for the analysis of the actual movement of the model,exhibiting certain engineering application value with robustness and simplicity.

关键词： Attitude determination MEMS Nonlinear complementary filter Quaternion Wind tunnel test

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Fabrication and characterization of multi-scale coated boron powders with improved combustion performance:A brief review

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Defence Technology（防务技术） 2024年第1期31卷 27-40页

作者： Rui Liu Danfeng Yang Kunyu xiong Ying-Lei Wang qi-Long Yan Science and Technology on Combustion Internal Flow and Thermo-structure LaboratoryNorthwestern Polytechnical UniversityXi'an710072China Xi'an Modern Chemistry Research Institute Xi'an710065China

Boron has high mass and volume calorific values,but it is difficult to ignite and has low combustion *** literature review summarizes the strategies that are used to solve the above-mentioned problems,which include coatings of boron by using fluoride compounds,energetic composites,metal fuels,and metal *** techniques include recrystallization,dual-solvent,phase transfer,electrospinning,*** one of the effective coating agents,the fluorine compounds can react with the oxide shell of boron *** comparison,the energetic composites can effectively improve the flame temperature of boron powder and enhance the evaporation efficiency of oxide film as a condensed *** and metal oxides would react with boron powder to form metal borides with a lower ignition point,which could reduce its ignition temperature.

关键词： Boron powder coating Structure and morphology Condensed phase thermal reaction Ignition and combustion

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Selective hydrogenation of 4-nitrostyrene to 4-nitroethylbenzene catalyzed by Pd@Ru core–shell nanocubes

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Rare Metals 2022年第4期41卷 1189-1194页

作者： Jing-Jing Fang qi-Ming Liu xiong-Wu Kang Shao-Wei Chen New Energy Technology Institute School of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Department of Chemistry and Biochemistry University of CaliforniaCA 95064USA

It is a challenge to selectively hydrogenate 4-nitrostyrene to 4-nitroethylbenzene,due to the similar energy barrier of hydrogenation of the nitro and vinyl ***,we demonstrate that such selective hydrogenation can be achieved by Pd@Ru core–shell nanocubes that are pre-pared by epitaxial growth of a face-centered cubic Ru shell on Pd *** core–shell structure of Pd@Ru nanocubes is conflrmed by transmission electron microscopy,X-ray diffraction spectroscopy,and elemental mapping *** is found that the electronic structure and hence the catalytic activity of the Pd@Ru nanocubes can be readily modulated by the Ru shell *** is manifested in electrochemical CO stripping measurements where a decrease of CO adsorption energy is observed on Pd@Ru nanocubes with the increase of the Ru shell *** from this study suggest that deliberate structural engineering can be exploited to prepare bimetallic core–shell nanostructures for highly active and selective hydrogenation of organic molecules with multi-functional moieties.

关键词： hydrogenation styrene benzene

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Measurement of He2* density with an auxiliary measuring electrode in atmospheric pressure plasma jet

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Plasma Science and Technology 2019年第8期21卷 51-56页

作者： Bing qi Chunxu qiN Haikun SHANG Li xiong Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology Ministry of EducationNortheast Electric Power UniversityJilin132012People’s Republic of China College of Biomedical Engineering Jilin Medical UniversityJilin132013People’s Republic of China

In this study, the density of metastable He2* in an atmospheric-pressure plasma jet operating in helium with 0.001% nitrogen has been measured using an auxiliary measuring electrode *** the glow discharge mode, waveforms from two grounding electrodes, including one main discharge electrode and one auxiliary electrode, are *** isolated current peak formed by Penning ionization in waveforms from the auxiliary measuring electrode is identified to calculate the density of metastable He2*.In our discharge environment, the helium metastable densities along the jet axis direction are between 2.26×1013 and 1.74×1013 cm-3,which is in good agreement with the results measured by other *** measurement technique can be conveniently applied to the diagnosis of metastable He2* in an atmospheric-pressure plasma jet array.

关键词： atmospheric plasma jet dielectric barrier discharge density of metastable helium

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Efficient conversion of lignin to alkylphenols over highly stable inverse spinel MnFe_(2)O_(4) catalysts

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Frontiers of Chemical Science and Engineering 2023年第8期17卷 1085-1095页

作者： Yi qi Xuezhi Zeng Lingyingzi xiong Xuliang Lin Bowen Liu Yanlin qin Guangdong Provincial Key Laboratory of Plant Resources Biorefinery School of Chemical Engineering and Light IndustryGuangdong University of TechnologyGuangzhou 510006China

The aromatic properties of lignin make it a promising source of valuable chemicals and *** efficient and stable catalysts to effectively convert lignin into high-value chemicals is *** this work,MnFe_(2)O_(4) spinel catalysts with oxygen-rich vacancies and porous distribution were synthesized by a simple solvothermal process and used to catalyze the depolymerization of lignin in an isopropanol solvent *** specific surface area was 110.5 m^(2)∙g^(–1),which substantially increased the active sites for lignin depolymerization compared to *** conversion of lignin reached 94%,and the selectivity of alkylphenols exceeded 90% after 5 h at 250℃.Underpinned by characterizations,products,and density functional theory analysis,the results showed that the catalytic performance of MnFe_(2)O_(4) was attributed to the composition of Mn and Fe with strong Mn–O–Fe *** addition,the cycling experiments and characterization showed that the depolymerized lignin on MnFe_(2)O_(4) has excellent cycling ***,our work provides valuable insights into the mechanism of lignin catalytic depolymerization and paves the way for the industrial-scale application of this process.

关键词： lignin depolymerization spinel catalysts hydrogenation

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An improved algorithm for McDowell＇s analytical model of residual stress

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Frontiers of Mechanical Engineering 2014年第2期9卷 150-155页

作者： Zhaoxu qi Bin LI Liangshan xiong Department of Mechanical Engineering Huazhong University of Science and Technology Wuhan 430074 China

The analytical elastoplastic rolling/sliding model for two-dimensional contact proposed by McDowell is an important tool for predicting residual stress in rolling/sliding processes. In application of the model, a problem of low predicting precision near the surface layer of the component is found. According to the volume- constancy of plastic deformation, an improved algorithm for McDowell＇s model is proposed in order to improve its predicting accuracy of the surface residual stress. In the algorithm, a relationship between three normal stresses perpendicular to each other at any point within the component is derived, and the relationship is applied to McDowell＇s model. Meanwhile, an unnecessary hypothesis proposed by McDowell can be eliminated to make the model more reasonable. The simulation results show that the surface residual stress predicted by modified method is much closer to the FEM results than the results predicted by McDowell＇s model under the same simulation conditions.

关键词： residual stress McDowell's model volume- constancy of plastic deformation FEM elastoplastic rolling/sliding contact

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Perovskite-type B-site Bi-doped ceramic membranes for oxygen separation

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Chinese Science Bulletin 2000年第10期45卷 889-893页

作者： Zongping Shao You cong Guoxing xiong Shishan Sheng Weishen Yang Chinese Acad Sci Dalian Inst Chem Phys State Key Lab Catalysis Dalian 116023 Peoples R China

Novel mixed conducting oxides, B-site Bi-doped perovskites were exploited and synthesized. Cubic perovskite structures were formed for BaBi0.2COyFe0.8-yO3-δ (y≤0.4) and BaBixCo0.2Fe0.8-xO3-δ (x=0.1 -0.5). The materials exhibited considerable high oxygen permeability at high temperature. The oxygen permeation flux of BaBi0.2Co0.35Fe0.45O3-δmembrane reached about0.77×106 mol/cm2 ·s under an air/helium oxygen partial pressure gradient at 900 ℃, which was much higher than that of other bismuth-contained mixed conducting membranes. The permeation fluxes of the materials increased with the increase of cobalt content, but no apparent simple relationship was found with the bismuth content. The materials also demonstrated excellent reversibility of oxygen adsorption and desorption. Stable time-related oxygen permeation fluxes were found for BaBi0.2Co0.

关键词： Bi2O3 mixed conductor inorganic membrane perovskite oxygen permeation.

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A New Method for Correcting Vehicle License Plate Tilt

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International Journal of Automation and computing 2009年第2期6卷 210-216页

作者： Mei-Sen Pan qi xiong Jun-Biao Yan Department of Computer Science and Technology Hunan University of Arts and Science Changde 415000 PRC Office of Academic Affairs Hunan University of Arts and Science Changde 415000 PRC

In the course of vehicle license plate （VLP） automatic recognition, tilt correction is a very crucial process. According to Karhunen-Loeve （K-L） transformation, the coordinates of characters in the image are arranged into a two-dimensional covariance matrix, on the basis of which the centered process is carried out. Then, the eigenvector and the rotation angle α are computed in turn. The whole image is rotated by -α. Thus, image horizontal tilt correction is performed. In the vertical tilt correction process, three correction methods, which are K-L transformation method, the line fitting method based on K -means clustering （LFMBKC）, and the line fitting based on least squares （LFMBLS）, are put forward to compute the vertical tilt angle θ. After shear transformation （ST） is imposed on the rotated image, the final correction image is obtained. The experimental results verify that this proposed method can be easily implemented, and can quickly and accurately get the tilt angle. It provides a new effective way for the VLP image tilt correction as well.

关键词： Tilt correction K-L transformation projection profile Hough transformation.

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Synthesis and characterization of trimethoxysilyl-functionalized poly(phthalazinone ether ketone)

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Chinese Chemical Letters 2007年第9期18卷 1137-1140页

作者： qi Feng Jin Gong xiong Liao Xi Gao Jian Department of Polymer Science & Materials Dalian University of Technology Dalian 116012 China

A novel alkoxysilyl-functionalized poly(phthalazinone ether ketone) (PPEK) was prepared for the boundary lubricant application in micro-electro-mechanical system (MEMS). The synthesis of functionalized PPEK was started from the hydroxylation of PPEK, then following with the corresponding ring-opening reaction of 3-glycidoxypropyltrimethoxysilane (GPTMS). The structures of the functional PPEK were confirmed by FTIR, 1H NMR, 29Si NMR, and UV–vis spectrum.

关键词： Phthalazinone Poly(aryl ether ketone) Glycidoxypropyltrimethoxysilane Synthesis

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