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Reentry Attitude Tracking Control for Hypersonic Vehicle with Reaction Control Systems via Improved Model Predictive Control Approach

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Computer Modeling in Engineering & Sciences 2020年第1期122卷 131-148页

作者： kai liu Zheng Hou Zhiyong She Jian guo 无 School of Aeronautics and Astronautics Dalian University of TechnologyDalian116024China Key Laboratory of Advanced Technology for Aerospace Vehicles Dalian116024China Beijing Institute of Aerospace Technology Beijing100074China

This paper studies the reentry attitude tracking control problem for hypersonic vehicles(HSV)equipped with reaction control systems(RCS)and aerodynamic *** attitude dynamical model of the hypersonic vehicles is established,and the simplified longitudinal and lateral dynamic models are obtained,***,the compound control allocation strategy is provided and the model predictive controller is designed for the pitch ***,considering the complicated jet interaction effect of HSV during RCS is working,an improved model predictive control approach is presented by introducing the online parameter estimation of the jet interaction coefficient for dealing with the uncertainty and ***,considering the strong coupling effect between the yaw channel and roll channel,a coupled model predictive controller is designed by introducing the feedback of sideslip angle into the roll control channel to eliminate the coupling ***,the comparison simulations using the classical control method,MPC and IMPC approach are given to demonstrate the effectiveness and efficiency of the presented IMPC scheme.

关键词： Hypersonic vehicle reentry attitude control mode predictive control jet interference factor reaction control systems

Hydrodynamic performances and wakes induced by a generic submarine operating near the free surface in continuously stratified fluid

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Journal of Hydrodynamics 2023年第3期35卷 396-406页

作者： liu-shuai Cao Gang Gao En-kai guo De-cheng Wan School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The wake of a submarine is a crucial element that greatly affects its stealth and hydrodynamic *** investigate the propagation and evolution characteristics of submarine wakes in a stratified fluid,particularly under free surface conditions,a numerical method to simulate the linearly stratified environment was developed.A thermocline model based on Boussinesq assumption was introduced to match the continuously stratified *** volume of fluid(VOF)method was utilized to capture free surface waves,while a fully structured grid and the SST k-ωturbulence model were combined to solve the complex flow of *** independence study in homogenous flow near the free surface was initially ***,the hydrodynamic performance,wake evolution characteristics,free surface signatures as well as decay of velocity under different stratification levels were *** demonstrated that the numerical method employed was efficient in simulating stratified ***,it showed that density stratification had a significant impact on the hydrodynamics and wake characteristics of a submarine,especially under strong density stratification circumstances.

关键词： Wakes submarine free surface stratified fluid hydrodynamics

Engineering atomic Rb-N configurations to tune radical pathways for highly selective photocatalytic H2O2 synthesis coupled with biomass valorization

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Journal of Energy Chemistry 2025年第1期100卷 215-225页

作者： Jiaye Li Shuang Pan Yihuang Chen Qiong liu College of Chemistry and Materials Engineering Wenzhou University Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology (China) Institute of Analysis Guangdong Academy of Sciences (China National Analytical CenterGuangzhou)

Photocatalytic oxygen reduction for hydrogen peroxide （H2O2） synthesis presents a green and costeffective production ***,achieving highly selective H2O2synthesis remains challenging,necessitating precise control over free radical reaction pathways and minimizing undesirable oxidative ***,we report for the visible light-driven simultaneous co-photocatalytic reduction of O2to H2O2and oxidation of biomass using the atomic rubidium-nitride modified carbon nitride（CNRb）.The optimized CNRb catalyst demonstrates a record photoreduction rate of 8.01 mM h-1for H2O2generation and photooxidation rate of 3.75 mM h-1for furfuryl alcohol to furoic acid,achieving a remarkable solar-to-chemical conversion （SCC） efficiency of up to 2.27%.Experimental characterizations and DFT calculation disclosed that the introducing atomic Rb–N configurations allows for the high-selective generation of superoxide radicals while suppressing hydroxyl free radical *** is because the Rb–N serves as the new alternative site to perceive a stronger connection position for O2adsorption and reinforce the capability to extract protons,thereby triggering a high selective redox product *** study holds great potential in precisely regulating reactive radical processes at the atomic level,thereby paving the way for efficient synthesis of H2O2coupled with biomass valorization.

关键词： Atomic economy Radical pathway regulation Rubidium atom coordination Biomass valorization

Mitigation of blackout problem for reentry vehicle in traveling magnetic field with induced current

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Plasma Science and Technology 2020年第12期22卷 37-47页

作者： Shaoshuai guo kai XIE Bin SUN Shaowei liu School of Aerospace Science and Technology Xidian UniversityXi'an 710071People's Republic of China

In this paper, a novel solution mitigating the radio blackout problem is proposed, which improves existing traveling magnetic field(TMF)-based methods. The most significant advance lies in replacing the external injection with self-induced current, which does not require electrodes. The improved analytical model is derived to evaluate the electron density reduction taking into consideration the self-induced current for various TMF velocities. The plasma reduction performance is analyzed for several conditions including the total absence of injected current. The results show that the velocity may be used to trade off the injected current and, when sufficiently large, eliminates the need for an injected current while mitigating radio blackout. The effectiveness of this solution to the blackout problem is demonstrated in commonly used aerospace communication bands. With a field strength of less than 0.15 T, increasing the velocity from40 m s^-1 to 3100 m s^-1 is all that is required to obviate the need for an injected current. Moreover,typical reduction ratios for electronic density tolerance(2, 1.9, 1.75 and 3 times for the L-, S-, Cand X-bands, respectively, at an altitude of 40 km) remain unchanged. Increasing the velocity of the TMF is much easier than injecting current via a metal electrode into a high-temperature flow field. The TMF method appears practical in regard to possible future applications.

关键词： blackout traveling magnetic field self-induced current traveling magnetic field velocity

Hydrodynamics and bubble behaviour in a three-phase two-stage internal loop airlift reactor

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Chinese Journal of Chemical Engineering 2018年第6期26卷 1359-1369页

作者： Dan Li kai guo Jingnan Li Yiping Huang Junchao Zhou Hui liu Chunjiang liu School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China State Key Laboratory of Chemical Engineering Tianjin University Tianjin 300072 China China Construction Industrial & Energy Engineering Co. Ltd. Nanjing210000 China

Local hydrodynamics of a gas–liquid–solid system,such as bubble circulation regime,gas holdup,liquid velocity and axial profile of solid concentration,are studied in a two-stage internal loop airlift *** correlations for gas holdup and liquid velocity are proposed to ease the reactor design and *** bubble circulation regimes were displayed in the first(lower) and second(upper) *** superficial gas velocity and solid loading can promote regime transition of the second stage,and the gas holdup of the second stage is higher than that of the lower *** addition,the effects of solid loading on bubble behaviour are experimentally investigated for each *** is found that bubble size in the downcomer decreases with the presence of solid particles,and bubble size distribution widens under higher superficial gas velocity and lower solid loading.

关键词： Two-stage internal loop airlift reactor Hydrodynamics Bubble Multiphase flow

Cobalt coordination modified double-schiff-base with low solubility as a long-cycle life anode for sodium-ion batteries

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Progress in Natural Science:Materials International 2022年第4期32卷 510-516页

作者： Mengyuan Yue Huinan guo Zhaoxia Yuan Weiqin Li Yafei liu kai Chen Yusang guo Yijing Wang Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Renewable Energy Conversion and Storage Center College of Chemistry Nankai University

Sodium-ion batteries（SIBs） have been recently considered as an intriguing candidate for next-generation battery systems with their advantages in large-scale energy storage applications. However, the design of electrode materials of SIBs still suffers from severe volume expansion and low capacity caused by the larger ion radius, high redox potential and heavy atom weight of Na. Organic electrode materials with structural flexibility have attracted great attention recently for their potential in alleviating volume expansion. However, most organic electrode materials suffer from dissolution in electrolytes and consequent capacity fading during the long-term cycling process. In this work, a method coordinating with Co2+was applied to solve the shuttle effect of H4salphdc(N, N'-phenylene-bis-（salicylideneimine） dicarboxylic acid). By virtue of the Co2+coordination, the Co（H2salphdc）electrode delivered a desirable discharge capacity of 123 m Ah g-1after 1500 cycles at the current density of 200m A g-1, while the H4salphdc electrode exhibited severe capacity fading. Such excellent electrochemical performance can be credited to the Co2+coordination repressing the electrode dissolution and improving the structure stability.

关键词： Double-Schiff-base Sodium-ion battery Shuttle effects

沉积温度对氮化铝压电薄膜性能影响及机制分析

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光电子·激光 2025年第1期36卷 107-112页

作者：郭燕刘小军王进南京理工大学泰州科技学院天津三安光电有限公司

高频光电通信器件对压电材料特性要求越来越高，氮化铝（AlN）薄膜由于其优异的压电特性而备受关注，高取向高压电AlN薄膜沉积工艺优化成为其应用拓展的瓶颈技术之一，众多制备工艺参数中温度是影响AlN薄膜晶格取向的关键参数之一。本... 详细信息

高频光电通信器件对压电材料特性要求越来越高，氮化铝（AlN）薄膜由于其优异的压电特性而备受关注，高取向高压电AlN薄膜沉积工艺优化成为其应用拓展的瓶颈技术之一，众多制备工艺参数中温度是影响AlN薄膜晶格取向的关键参数之一。本文采用磁控溅射的方法沉积AlN薄膜，研究了沉积温度对AlN薄膜晶体取向及压电性能的影响，X射线衍射（X-ray diffraction, XRD）测试结果表明，250℃下可获得（100）取向AlN,300℃下AlN则优先（002）取向；压电测试结果表明，250℃下压电常数d*33达最大值0.79 V,表现出较优的压电特性。基于原子力显微镜（atomic force microscopy, AFM）结果及温度对价键稳定性影响分析探索了温度对其生长的影响机制。

关键词：氮化铝(AlN) 衬底温度取向生长压电特性

Interconnections between diabetic corneal neuropathy and diabetic retinopathy:diagnostic and therapeutic implications

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Neural Regeneration Research 2025年第8期20卷 2169-2180页

作者： Mingyi Yu Faith Teo En Ning Chang liu Yu-Chi liu Tissue Engineering and Stem Cell Group Singapore Eye Research InstituteSingapore Yong Loo Lin School of Medicine National University of SingaporeSingapore Department of Cornea and External Eye Disease Singapore National Eye CenterSingapore Ophthalmology and Visual Sciences Academic Clinical Program Duke-NUS Medical SchoolSingapore

Diabetic corneal neuropathy and diabetic retinopathy are ocular complications occurring in the context of diabetes *** corneal neuropathy refers to the progressive damage of corneal *** retinopathy has traditionally been considered as damage to the retinal ***,growing evidence suggests that diabetic retinopathy is a complex neurovascular disorder resulting from dysfunction of the neurovascular unit,which includes both the retinal vascular structures and neural *** retinopathy is one of the leading causes of blindness and is frequently screened for as part of diabetic ocular ***,diabetic corneal neuropathy is commonly overlooked and underdiagnosed,leading to severe ocular surface *** studies have found that these two conditions tend to occur together,and they share similarities in their pathogenesis pathways,being triggered by a status of chronic *** review aims to discuss the interconnection between diabetic corneal neuropathy and diabetic retinopathy,whether diabetic corneal neuropathy precedes diabetic retinopathy,as well as the relation between the stage of diabetic retinopathy and the severity of corneal *** also endeavor to explore the relevance of a corneal screening in diabetic eyes and the possibility of using corneal nerve measurements to monitor the progression of diabetic retinopathy.

关键词： cornea corneal nerves diabetes diabetic corneal neuropathy diabetic retinopathy retina

柱前衍生化反相高效液相色谱法测定蝉蜕中3种氨基酸含量

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安徽中医药大学学报 2017年第2期36卷 80-83页

作者：张楠刘劲松王国凯郑娟刘松照安徽中医药大学药学院现代中药安徽省重点实验室安徽合肥230012

目的建立柱前衍生化反相高效液相色谱法测定蝉蜕中天冬氨酸、酪氨酸和缬氨酸3种氨基酸含量的方法。方法采用酸水解法制备氨基酸样品溶液,以异硫氰酸苯酯柱前衍生化后进行高效液相色谱分析。采用Kromasil C18色谱柱(250 mm×4.6 mm),梯... 详细信息

目的建立柱前衍生化反相高效液相色谱法测定蝉蜕中天冬氨酸、酪氨酸和缬氨酸3种氨基酸含量的方法。方法采用酸水解法制备氨基酸样品溶液,以异硫氰酸苯酯柱前衍生化后进行高效液相色谱分析。采用Kromasil C18色谱柱(250 mm×4.6 mm),梯度洗脱,流动相A为0.1 mol/L醋酸钠缓冲液-乙腈(93∶7),流动相B为乙腈-水(4∶1),流速1.0 mL/min,柱温为43℃,检测波长254nm,进样量20μL。结果氨基酸衍生溶液在36h内保持稳定,3种氨基酸在线性范围内峰面积与浓度的相关系数均大于0.999 0,加样回收率(n=6)分别为95.62%、101.26%和100.00%。结论所建立的检测方法稳定可靠,精密度和重复性良好,可用于蝉蜕中天冬氨酸、酪氨酸、缬氨酸含量测定。

关键词：柱前衍生化蝉蜕氨基酸高效液相色谱法