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Microscale spherical TiO_(2)powder prepared by hydrolysis of TiCl_(4)solution:Synthesis and kinetics

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Particuology 2024年第1期84卷 60-71页

作者： Peiyi Yan ying Zhang Shili zheng School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China Key Laboratory of Green Process and Engineering National Engineering Research Center of Green Recycling for Strategic Metal ResourcesInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization Panzhihua617000China

Hydrolysis of TiCl_(4)solution is capable of preparing microscale TiO_(2)*** research studied the synthesis of microscale spherical TiO_(2)powders and the hydrolysis *** effects of the flow field generated by different agitators and baffles in the crystallizer,the initial free acid concentration,the initial equivalent TiO_(2)concentration,and the temperature on the hydrolysis progress and powder morphology were systematically *** results show that the flow field in a crystallizer can significantly affect the morphology and particle size of the powders,and the axial flow can improve the sphericity of the *** increased free HCl and equivalent TiO_(2)concentrations in the pregnant solution inhibit the forward hydrolysis reaction,prolong the time to reach equilibrium,and reduce the *** appropriate temperature matching the compositions of the pregnant solution is crucial for the powder morphology and *** with sizes ranging from around 5 um-40μm can be tuned under controlled flow field,solution compositions,and temperature *** addition,the Cheng and Wunderlich modified Avrami equation was used for the crystallization kinetic *** effects of the free HCl concentration,equivalent TiO_(2)concentration,and hydrolysis temperature are reflected in the reaction rate constant and active nuclei reduction *** the free HCl and equivalent TiO_(2)concentrations will reduce the reaction rate constant and accelerate the deactivation of the active nuclei,thus increasing the final powder size,while increasing the temperature will lead to the opposite results.

关键词： TiCl_(4) Hydrolysis Microscale TiO_(2) Spherical Kinetics

Hot Workability of the as-Cast 21Cr Economical Duplex Stainless Steel Through Processing Map and Microstructural Studies Using Different Instability Criteria

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Acta Metallurgica Sinica(English Letters) 2017年第11期30卷 1080-1088页

作者： Jing Han Jia-Peng Sun ying Han huan Liu School of Mechanical and Electrical Engineering China University of Mining and Technology College of Mechanics and Materials Hohai University Key Laboratory of Advanced Structural Materials Ministry of EducationChangchun University of Technology

To develop a fundamental understanding of the flow behavior and optimal hot workability parameters of this material, the hot workability and deformation mechanisms of the as-cast 21Cr EDSS were studied using processing map technology combined with microstructure analysis and isothermal hot compression over the temperature range of 1000-1150 ℃ and strain rate range of 0.01-10 s-1. The processing maps and constitutive equation of peak stress were developed based on Prasad＇s and Murty＇s criteria. The results show that the processing maps exhibit a stable domain at 1000-1150 ℃ and 0.01-1 s-1. The instability domain is exhibited at high strain rates （≥1 s-l）. This implies that Murty＇s criterion can predict the unstable domain with high reliability. The detailed deformation mechanisms are also studied by microstructure observation, showing that the flow localization and microcracking are responsible for the flow instability.

关键词： Duplex stainless steel Constitutive relationship Processing map Hot deformation behavior

Navigation Finsler metrics on a gradient Ricci soliton

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 266-275页

作者： LI ying MO Xiao-huan WANG Xiao-yang Department of Applied Mathematics Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Pure and Applied Mathematics School of Mathematical SciencesPeking UniversityBeijing 100871China School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 100081China

In this paper,we study a class of Finsler metrics defined by a vector field on a gradient Ricci *** obtain a necessary and sufficient condition for these Finsler metrics on a compact gradient Ricci soliton to be of isotropic S-curvature by establishing a new integral *** we determine the Ricci curvature of navigation Finsler metrics of isotropic S-curvature on a gradient Ricci soliton generalizing result only known in the case when such soliton is of Einstein *** its application,we obtain the Ricci curvature of all navigation Finsler metrics of isotropic S-curvature on Gaussian shrinking soliton.

关键词： gradient Ricci soliton navigation Finsler metric isotropic S-curvature Ricci curvature Gaussian shrinking soliton

A Note on "Doubly Periodic Propagating Wave for (2+1)-Dimensional Breaking Soliton Equation"

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Communications in Theoretical Physics 2009年第1期51卷 79-80页

作者： zheng Chun-Long PAN Zhen-huan MA zheng-Yi School of Physics and Mechanical Engineering Shaoguan University Shaoguan 512005 China College of Mathematics and Physics Lishui University Lishui Zhejiang 323000 China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

In a recent paper [Commun. Theor. Phys. （Beijing, China） 49 （2008） 268], huang et al. gave a general variable separation solution to the （2＋1）-dimensional breaking soliton equation via a special Biicldund transformation and the variable separation approach. In terms of the derived variable separation solution and by introducing Jacobi elliptic functions, they claimed that nonelastic types of interaction between Jacobi elliptic function waves are investigated both analytically and graphically. We show that some inappropriateness or errors exist in their paper, and say nothing of the conclusion that some nonelastic types of interaction between Jacobi elliptic function waves in the （2＋1）-dimensional breaking soliton equation have been found.

关键词： breaking soliton equation variable separation solution interaction comment

Dynamics and response reshaping of nonlinear predator-prey system undergoing random abrupt disturbances

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Applied Mathematics and Mechanics(English Edition) 2021年第8期42卷 1123-1134页

作者： Lei XIA Jiaojiao SUN Zuguang ying Ronghua huan Weiqiu ZHU Department of Mechanics Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang UniversityHangzhou 310027China

An actual ecological predator-prey system often undergoes random environmental mutations owing to the impact of natural disasters and man-made destruction, which may destroy the balance between the species. In this paper,the stochastic dynamics of the nonlinear predator-prey system considering random environmental mutations is investigated, and a feedback control strategy is proposed to reshape the response of the predator-prey system against random abrupt environmental mutations. A delayed Markov jump system(MJS) is established to model such a predator-prey system. A novel first integral is constructed which leads to better approximation solutions of the ecosystem. Then, by applying the stochastic averaging method based on this novel first integral, the stochastic response of the predator-prey system is investigated, and an analytical feedback control is designed to reshape the response of the ecosystem from the disturbed state back to the undisturbed *** simulations finally illustrate the accuracy and effectiveness of the proposed procedure.

关键词： random excitation nonlinear dynamics reshaping control stationary probability density function(SPDF) predator-prey system

Simulation of Damage Evolution and Study of Multi-Fatigue Source Fracture of Steel Wire in Bridge Cables under the Action of Pre-Corrosion and Fatigue

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Computer Modeling in Engineering & Sciences 2019年第8期120卷 375-419页

作者： ying Wang Yuqian zheng Jiangsu Key Laboratory of Engineering Mechanics School of Civil EngineeringSoutheast UniversityNanjing211189China

A numerical simulation method for the damage evolution of high-strength steel wire in a bridge cable under the action of pre-corrosion and fatigue is presented in this *** on pitting accelerated crack nucleation theory in combination with continuum mechanics,cellular automata technology(CA)and finite element(FE)analysis,the damage evolution process of steel wire under pre-corrosion and fatigue is *** method automatically generates a high-strength steel wire model with initial random pitting defects,and on the basis of this model,the fatigue damage evolution process is simulated;thus,the fatigue life and fatigue performance of the corroded steel wire can be evaluated.A comparison of the numerical simulation results with the experimental results shows that this method has strong reliability and practicability in predicting the fatigue life of corroded steel wire and simulating the damage evolution *** on the method proposed in this paper,the fatigue life of steel wires with different degrees of corrosion under the action of different stress levels is *** results show that as the degree of corrosion increases,the fatigue properties of steel wire gradually decrease,and the influence of existing pitting corrosion on fatigue life is far greater than that on mass *** concentration is the main cause of fatigue life of corroded steel wire in advance *** addition,the fracture process of steel wire with multi-fatigue sources and the effect of the number and distribution of pits on the fatigue life of steel wire are *** results show that,compared with a stepped pitting distribution,a planar pitting distribution has a greater impact on the damage evolution *** fatigue life of steel wire is positively correlated with the number of pits and the angle and distance between pits.

关键词： Steel wire damage evolution pre-corrosion and fatigue multi-fatigue source fracture cellular automata

Almost Periodic Solutions by the Harmonic Balance Method

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Acta Mathematicae Applicatae Sinica 2022年第4期38卷 943-954页

作者： Ji-feng CHU Zuo-huan zheng Zhe ZHOU Department of Mathematics Shanghai Normal UniversityShanghai 200234China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China College of Mathematics and Statistics Hainan Normal UniversityHaikou 571158China

We consider non-autonomous ordinary differential equations in two *** is the one-dimensional case that admits a condition of hyperbolicity,and the other one is the higher-dimensional case that admits an exponential *** differential equations of this kind,we give a rigorous treatment of the Harmonic Balance Method to look for almost periodic solutions.

关键词： almost periodic solution Harmonic balance method exponential dichotomy

Low concentration isopropanol gas sensing properties of Ag nanoparticles decorated In_(2)O_(3) hollow spheres

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Journal of Advanced Ceramics 2022年第3期11卷 379-391页

作者： Chao ZHANG Yunchun huan ying LI Yifan LUO Marc DEBLIQUY College of Mechanical Engineering Yangzhou UniversityYangzhou225127China Materials Science Department University of MonsMons7000Belgium

In order to detect low concentrations of volatile organic compounds (VOCs) for the early diagnosis of lung cancer, sensors based on hollow spheres of In_(2)O_(3) were prepared through the soft template method. Ag nanoparticle decorated In_(2)O_(3) composites were synthesized via dipping and annealing. The microstructure, phase composition, element distribution, and state of Ag were analyzed by the scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The gas sensing tests showed that Ag-In_(2)O_(3) sensors had the highest response to isopropanol at 300 ℃. The best response of Ag-In_(2)O_(3) composite sensor was 5.2, which had a significant improvement compared with only In_(2)O_(3). Moreover, the response and recovery time of Ag-In_(2)O_(3) composite sensor was significantly shortened. The improved sensing properties of Ag-In_(2)O_(3) composite sensor could be attributed to the Schottky barrier created at Ag-In_(2)O_(3) interface and catalytical effect of Ag.

关键词： Ag-In_(2)O_(3) hollow spheres isopropanol gas sensor

Tunable Phase Structure of Side-chain Liquid Crystalline Polymers Enabled by Molecular Engineering of Dual Mesogenic Cores

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Chinese Journal of Polymer Science 2024年第10期42卷 1459-1469,I0009页

作者： Wen-huan Yao Lan-Sheng Liu Jie Zhao Yan-Xia Wang An-Zhi Ma zheng-Rui Ma Lan-ying Zhang Ruo-Chen Lan College of Chemistry and Chemical Engineering Hunan UniversityChangsha410082China Key Laboratory of Eco-Functional Polymer Materials of the Ministry of Education Key Laboratory of Eco-Environmental Polymer Materials of Gansu ProvinceCollege of Chemistry and Chemical EngineeringNorthwest Normal UniversityLanzhou730070China Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing100871China Institute of Advanced Materials&Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education College of Chemistry and Chemical EngineeringJiangxi Normal UniversityNanchang330022China

A series of novel side-chain liquid crystalline(SCLC)copolymers were synthesized by attaching two distinct mesogenic units,namely a chiral cholesteryl-based monomer(M1)and an achiral biphenyl-based monomer(M2),to a poly(3-mercaptopropylmethylsiloxane)(PMMS)backbone via thiol-ene click *** influence of side chain composition on the self-assembly behavior and phase structures of these SCLC copolymers was systematically investigated using different *** indicate that three distinct liquid crystalline phases and four unique molecular configurations were identified within the polymer series,with the emergence of the liquid crystalline phase being a synergistic outcome of the two distinct side *** study underscores the critical influence of side chain dimensions,rigidity,and spatial volume on the self-assembly structures and phase characteristics of liquid crystalline polymers,providing valuable insights for the rational design and development of advanced functional materials with tailored properties.

关键词： Liquid crystalline copolymers Self-assembly Phase structure Chiral molar ratio