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Some special exact solutions in nonlocal Alice-Bob sine-Gordon systems

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Communications in Theoretical Physics 2023年第2期75卷 39-45页

作者： Zong-ao zhang Sen-Yue Lou School of Mathematics and Statistics Ningbo UniversityNingbo315211China School of Physical Science and Technology Ningbo UniversityNingbo315211China

Three nonlocal Alice-Bob sine-Gordon(ABSG) systems with the parity and time reversal nonlocality and/or space-time exchange nonlocality are investigated. For the common local SG equation, two types of N-soliton solutions and three types of periodic solutions are presented. The multiple solutions, breather solution, double kink solution, and periodic solutions of the ABSG systems are obtained from the symmetry reductions of a coupled local sine-Gordon system.

关键词： sine-Gordon equation parity and time reversal soliton solutions periodic solutions

Back-Stepping Control for Flexible Air-Breathing Hypersonic Vehicles Based on Uncertainty and Disturbance Estimator

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Journal of Beijing Institute of Technology 2020年第4期29卷 504-513页

作者： Lin Cao Dong zhang ao zhang System Engineering Institute of Sichuan Aerospace Chengdu 610100China College of Astronautics Northwestern Polytechnical UniversityXi’an 710072China

A theoretical framework of nonlinear flight control for a flexible air-breathing hypersonic vehicle(FAHV)is proposed in this *** order to suppress the system uncertainty and external disturbance,an uncertainty and disturbance estimator(UDE)based back-stepping control strategy is designed for a dynamic state-feedback controller to provide stable velocity and altitude ***,the longitudinal dynamics of FAHV is simplified into a closure loop form with lumped uncertainty and *** the UDE is applied to estimate the lumped uncertainty and disturbance for the purpose of control input *** a nonlinear tracking differentiator is introduced to solve the problem of“explosion of term”in the back-stepping *** stability of the UDE-based control strategy is proved by using Lyapunov stability ***,simulation results are presented to demonstrate the capacity of the proposed control strategy.

关键词： flexible air-breathing hypersonic vehicle(FAHV) uncertainty and disturbance estimator(UDE) back-stepping control

Generalized degradation reliability model considering phase transition

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Journal of Systems Engineering and Electronics 2022年第3期33卷 748-758页

作者： zhang ao WANG Zhihua WU Qiong LIU Chengrui School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Institute of Spacecraft System Engineering China Academy of Space TechnologyBeijing 100094China Beijing Institute of Control Engineering Beijing 100094China

Aiming to evaluate the reliability of phase-transition degrading systems,a generalized stochastic degradation model with phase transition is constructed,and the corresponding analytical reliability function is formulated under the concept of the first hitting *** phase-varying stochastic property and the phase-varying nonlinearity are considered simultaneously in the proposed *** capture the phase-varying stochastic pro-perty,a Wiener process is adopted to model the non-monotonous degradation phase,while a Gamma process is utilized to model the monotonous *** addition,the phase-varying non-linearity is captured by different transformed time scale *** facilitate the practical application of the proposed model,identification of phase model type and estimation of model parameters are discussed,and the initial guesses for parameters optimization are also *** on the constructed model,two simulation studies are carried out to verify the analytical reliability function and analyze the influence of model ***,a practical case study is conducted for illustration.

关键词： degradation phase transition reliability stochastic process nonlinearity

Anchorage properties at the interface between soil and roots with branches

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Journal of Forestry Research 2017年第1期28卷 83-93页

作者： Xiaodong Ji Lihua Chen ao zhang Key Laboratory of Soil and Water Conservation and Desertification Combating Ministry of Education of ChinaBeijing Forestry University100083 BeijingChina

Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve （F-S curve）. The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures： breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches： the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage.

关键词： Root-soil interface mechanics Pullout test method Root branches Branch angle

Alectinib: a novel second generation anaplastic lymphoma kinase(ALK) inhibitor for overcoming clinically-acquired resistance

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Acta Pharmaceutica Sinica B 2015年第1期5卷 34-37页

作者： Zilan Song Meining Wang ao zhang CAS Key Laboratory of Receptor Research Synthetic Organic & Medicinal Chemistry LaboratoryShanghai Institute of Materia Medica (SIMM) Chinese Academy of Sciences

The development of inhibitors for the tyrosine anaplastic lymphoma kinase (ALK) has advanced rapidly, driven by biology and medicinal chemistry. The first generation ALK inhibitor crizotinib was granted US FDA approval with only four years of preclinical and clinical testing. Although this drug offers significant clinical benefit to the ALK-positive patients, resistance has been developed through a variety of mechanisms. In addition to ceritinib, alectinib is another second-generation ALK inhibitor launched in 2014 in Japan. This drug has a unique chemical structure bearing a 5H-benzo[b] carbazol-11(611)-one structural scaffold with an IC50 value of 1.9 nmol/L, and is highly potent against ALK bearing the gatekeeper mutation L1196M with an IC50 of 1.56 nmoL/L. In the clinic, alectinib is highly efficacious in treatment of ALK-positive non-small cell lung cancer (NSCLC), and retains potency to combat crizotinib-resistant ALK mutations L11.96.M, F1174L, R1275Q and C1156Y. (C) 2015 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V. All rights reserved.

关键词： Tyrosine anaplastic lymphoma kinase Alectinib Crizotinib Non-suaall cell lung cancer Resistance ALK mutations EML4-ALK

Three-dimensional Molecular Geometry of PEG Hydrogels by an “Expansion-Contraction” Method through Monte Carlo Simulations

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Chinese Journal of Polymer Science 2015年第5期33卷 721-731页

作者： ao-kai zhang 凌君 Yu-wei Sun 付国东 School of Chemistry and Chemical Engineering Southeast University Department of Polymer Science and Engineering Zhejiang University

Three-dimensional（3-D） coarse-grained Monte Carlo algorithms were used to simulate the conformations of swollen hydrogels formed by copper（I）-catalyzed azide-alkyne cycloaddition（Cu AAC）. The simulation consists of three successive steps including diffusion, cross-linking and relaxation. The cross-linking of multifunctional reaction sites is simulated instantly followed by fast crosslinking. In order to explore the validity of this approach pristine poly（ethylene glycol）（PEG） hydrogels with tri- and tetra-functional reaction sites（G3 and G4 respectively） were prepared and characterized. The data from the simulations were found to be in good agreement with experimental results such as PEG lengths between crosslinks, pore volume and pore radius distribution, indicating the validity of the modeling algorithm. The calculated PEG lengths in G3 and G4 networks are close（≈ 4.6 nm）. The 3-D visual topological structure of the hydrogel network suggests that the ＂ideal＂ hydrogel is far from cubic, diamond or any well defined structures of regular repeating cells.

关键词： Monte Carlo Hydrogel Molecular geometry Cu AAC

Synthesis Study toward Mayamycin

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Chinese Journal of Chemistry 2013年第1期31卷 93-99页

作者： Kui Wu Meining Wang Qizheng Yao ao zhang Department of Medicinal Chemistry China Pharmaceutical University Nanjing Jiangsu 210009 China Synthetic Organic & Medicinal Chemistry Laboratory Shanghai Institute ofMateria Medica Chinese Academy of Sciences Shanghai 201203 China

Natural product mayamycin is the first example in the angucycline class featuring a C-glycoside linkage at the C5-position of the benz[a]anthracenone core with remarkable biological activities. We successfully synthesized the two retrosynthetic fragments, but found that the final C-glycosylation did not occur. Alternatively, an A-ring satu- rated aglycon was prepared, but the proposed C-glycosylation still did not proceed. Finally, a simplified substrate was used and the subsequent C-glycosylation went through smoothly, giving a two-ring less analogue of mayamy- cin.

关键词： natural product angucycline mayamycin total synthesis C-glycosilation

CeO_2 as the Oxygen Carrier for Partial Oxidation of Methane to Synthesis Gas in Molten Salts: Thermodynamic Analysis and Experimental Investigation

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Journal of Natural Gas Chemistry 2007年第1期16卷 6-11页

作者： Yonggang Wei Hua Wang Fang He Xianquan ao Chiyuan zhang Faculty of Materials and Metallurgy Engineering Kunming University of Science and Technology Kunming 650093 Yunnan China

A new technique -- the direct partial oxidation of methane to synthesis gas using lattice oxygen in molten salts medium has been introduced. Using CeO2 as the oxygen carrier, thermodynamic data were calculated in the reaction process, and the results indicated that direct partial oxidation of methane to synthesis gas using lattice oxygen of cerium oxide is feasible in theory. In a stainless steel reactor, the effects of temperature and varying amounts of γ-Al2O3 supported CeO2 on cn4 conversion, H2 and CO selectivity, were investigated, respectively. The results show that 10% CeO2/γ-Al2O3 has the maximal reaction activity at a temperature of 865 ℃ and above, the H2/CO ratio in the gas that has been produced reaches 2 and the CH4 conversion, H2 and CO selectivity reached the following percentages： i.e. 61%, 89%, and 91% at 870 ℃, respectively. In addition, increase of reaction temperature is favorable for the partial oxidation of methane.

关键词： partial oxidation methane cerium oxide synthesis gas molten salt

基于锥形超晶格p-AlInGaN层的AlGaN基深紫外发光二极管性能优化

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原子与分子物理学报 2025年第1期42卷 101-107页

作者：许愿张傲翔张鹏飞王芳刘俊杰刘玉怀郑州大学电气与信息工程学院电子材料与系统国际联合研究中心、河南省电子材料与系统国际联合实验室郑州450001 郑州大学智能传感研究院郑州450001 郑州大学产业技术研究院有限公司郑州450001 郑州唯独电子科技有限公司郑州450001 北方民族大学电气与信息工程学院银川750001

为了解决AlGaN基深紫外(DUV)发光二极管(LED)中的严重电子溢出和低空穴注入的问题,本文提出了一种新型锥形超晶格p-AlInGaN层,它大幅改善了基于AlGaN的DUV LED的光电特性.与传统结构相比,所提出结构的输出功率提高了337.8%;同时它的内... 详细信息

为了解决AlGaN基深紫外(DUV)发光二极管(LED)中的严重电子溢出和低空穴注入的问题,本文提出了一种新型锥形超晶格p-AlInGaN层,它大幅改善了基于AlGaN的DUV LED的光电特性.与传统结构相比,所提出结构的输出功率提高了337.8%;同时它的内部量子效率(IQE)也高达96%,并且没有效率下降现象.仿真计算结果表明,锥形超晶格p-AlInGaN层的引入明显增加了多量子阱(MQWs)内载流子的浓度并降低了量子阱(QWs)内的电场,导致了更高的辐射复合率,为改善DUV LED的性能提供了一个有吸引力的解决方案.

关键词：深紫外发光二极管 AlInGaN 锥形超晶格内部量子效率辐射复合