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Reversible isomerization of donor-acceptor Stenhouse adduct derivatives in water through dendritic confinement

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Science China Chemistry 2024年第5期67卷 1636-1646页

作者： Jiaxing zhang Qingyun Zhao Xinyan Su Afang zhang Wen Li International Joint Laboratory of Biomimetic and Smart Polymers School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

Modulating reversible isomerization of hydrophobic dyes in aqueous solutions is greatly desired. Here we report on reversible isomerization of solvatochromic donor-acceptor Stenhouse adducts(DASAs) in water through the confinement from dendritic oligoethylene glycols(OEGs). Dendronization of DASAs with dendritic OEGs affords them characteristic thermoresponsiveness. These dendronized DASAs spontaneously isomerize in water from hydrophobic linear state into hydrophilic cyclic state at room temperature due to the strong hydration. However, hydrophobic microenvironment through thermally dehydration and collapse of the dendritic OEGs at elevated temperatures confines hydration of the DASA moieties and mediates their interactions with the collapsed hydrophobic OEG domains, affording their isomerization recovery in water efficiently from the hydrophilic cyclic state into the hydrophobic linear state. The confinement-mediated reversible isomerization of DASA moieties in water can be repeated through alternative photo-irradiation and thermal dehydrations, exhibiting excellent fatigue resistance.

关键词： dendrimers donor-acceptor Stenhouse adducts isomerization confinement thermoresponsiveness

Chronic administration of triclosan leads to liver fibrosis through hepcidin-ferroportin axis-mediated iron overload

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Journal of Environmental Sciences 2024年第3期137卷 144-154页

作者： Jing Liu Lecong zhang Fang Xu Ping zhang Yang Song College of Eco-Environmental Engineering Guizhou Minzu UniversityGuiyang 550025China The Institute of Karst Wetland Ecology Guizhou Minzu UniversityGuiyang 550025China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Triclosan(TCS)has been manufactured as an antibacterial compound for half a ***,it is widely used in various personal care products;however,its potential adverse effects raise a lot of ***,we create a long-term oral administration mouse model and identify the corresponding hepatotoxicity of *** discover that daily intragastric administration of 10 mg/kg TCS to mice for 12 weeks results in severe hepatic *** study displays that hepatic iron increased 18%,23%and 29%upon oral TCS treatment for4,8 and 12 weeks,*** by hepatic iron variation,splenic and duodenal iron are increased,which indicates systemic iron *** only excessive iron accumulated in the liver,abnormal hepatic malondialdehyde,prostaglandin synthase 2 and glutathione peroxidase 4 are pointed to *** study uncovers that hepcidin expression increases 7%,10%,4%in serum and 2.4-,4.8-,and 2.3-fold on transcriptional levels upon TCS exposure for 4,8 and 12 weeks,*** together,the mice in the TCS-treated group show disordered systemic iron homeostasis via the upregulated hepatic hepcidin-ferroportin ***,both hepatic iron overload(systemic level)and hepatocyte ferroptosis(cellular level)are accused of TCS-induced liver ***■,an iron scavenger,significantly ameliorates TCS-induced liver *** summary,this study confirms the impact of TCS on liver fibrosis;a critical signal pathway is also *** significance of the current study is to prompt us to reevaluate the“pros and cons”of TCS applications.

关键词： Triclosan Iron metabolism Hepcidin Hepatotoxicity Liver fibrosis

Optimal Planning of Hybrid AC/DC Low-voltage Distribution Networks Considering DC Conversion of Three-phase Four-wire Low-voltage AC Systems

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 141-153页

作者： Bo zhang Lu zhang Wei Tang Gen Li Chen Wang the College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China the Electric Energy Group Department of Engineering TechnologyTechnical University of Denmark(DTU)2750 BallerupDenmark the Power Distribution Technology Center State Grid Beijing Electric Power Research InstituteBeijing 100075China

The increasing integration of distributed household photovoltaics(PVs)and electric vehicles(EVs)may further ag gravate voltage violations and unbalance of low-voltage distribu tion networks(LVDNs).DC distribution networks can increase the accommodation of PVs and EVs and mitigate mutilple pow er quality problems by the flexible power regulation capability of voltage source *** paper proposes schemes to es tablish hybrid AC/DC LVDNs considering the conversion of the existing three-phase four-wire low-voltage AC systems to DC op *** characteristics and DC conversion constraints of typical LVDNs are *** addition,converter configura tions for typical LVDNs are proposed based on the three-phase four-wire characteristics and quantitative analysis of various DC ***,an optimal planning method of hybrid AC/DC LVDNs is proposed,which is modeled as a bi-level programming model considering the annual investments and three-phase *** are conducted to verify the effectiveness of the proposed optimal planning *** ulation results show that the proposed optimal planning method can increase the integration of PVs while simultaneously reduc ing issues related to voltage violation and unbalance.

关键词： Optimal planning low-voltage distribution net work three-phase unbalance DC conversion

Compensated acceleration feedback based active disturbance rejection control for launch vehicles

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Chinese Journal of Aeronautics 2024年第4期37卷 464-478页

作者： Xiaoyan zhang Wenchao XUE Zibo LIU Ran zhang Huifeng LI Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Astronautics Beihang UniversityBeijing 100191China

In this paper, the attitude tracking and load relief control problems against wind disturbances and uncertain aerodynamics as well as the engine thrust of launch vehicles are ***, a framework of Compensated Acceleration Feedback based Active Disturbance Rejection Control(CAF-ADRC) is established to achieve both desired attitude tracking and load relief performances. In particular, the total disturbance that includes the effects caused by both aerocoefficient perturbations and disturbances is estimated by constructing an Extended State Observer(ESO) to achieve attitude tracking. Furthermore, combined with the normal acceleration due to the engine thrust, the accelerometer measurement is also compensated to enhance the load relief ***, the quantitative analysis of ESO and the entire closed-loop system are studied. It can be concluded that the desired attitude tracking and load relief performances can be achieved simultaneously under the proposed approach. Besides, tuning laws of the proposed approach are systematically given, which are divided into ESO, Proportional Derivative(PD) and Compensated Acceleration Feedback(CAF) modules. Moreover, the performances under CAF-ADRC approach can be better than those under CAF based PD(CAF-PD) approach by tuning load relief ***, the approach presented is applied to a typical control problem of launch vehicles with wind disturbances and parameter uncertainties.

关键词： Launch vehicles Uncertainty analysis Active disturbance rejection control(ADRC) Load relief control Extended state observer(ESO)

Numerical Investigation on Characteristics of Supercritical CO_(2)Heat Transfer in Vertical Circular Tubes with Circumferentially Half-Side Heating

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Journal of Thermal Science 2024年第5期33卷 1744-1756页

作者： zhang Yan zhang Xinyi YAN Chenshuai WU Wenhua GAO Erman School of Energy and Power Engineering Northeast Electric Power UniversityJilin 132012China

The design of heat exchangers in the advanced supercritical power conversion system cannot be separated from the study of heat transfer ***-side heating mode is often encountered for solar receiver and supercritical ***,the characteristics of supercritical CO_(2)(sCO_(2))convection heat transfer in vertical tubes with circumferentially half-side heating was numerically investigated through the SST k-ωturbulent model which matches well with the experimental ***,heat transfer between sCO_(2)upflow and downflow was *** to film boiling heat transfer at subcritical pressure,numerical results were processed according to the supercritical pseudo-phase transition hypothesis,with liquid-like phase in the tube core region and vapor-like film in the region near the heated tube *** structure of two layers was demarcated by pseudo-critical temperature T_(pc).Therefore,sCO_(2)heat transfer was assessed according to double thermal resistances caused by vapor-like film near the wall and core liquid-like *** findings suggest that wall temperature for upflow is higher than that for downflow,which is attributed to larger thermal resistance in the fluid domain for upflow than that for *** difference guarantees the excellent heat transfer performance for downflow than *** is also further concluded that the formation of vapor-like film near the wall due to pseudo-phase transition plays a key role in dominating wall temperature and inducing heat transfer deterioration in half-side heating *** present contribution is significant to the design of supercritical heat exchanger under half-side heating mode.

关键词： supercritical CO_(2) pseudo-phase transition half-side heating thermal resistance flow direction

Characteristics of a pre-combustion plasma jet igniter

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Chinese Journal of Aeronautics 2024年第7期37卷 178-189页

作者： Jinlu YU Baowen zhang Yang YU Bingbing ZHAO Lei zhang Aviation Engineering School Air Force Engineering UniversityXi’an 710038China Equipment Management and Unmanned Aerial Vehicle Engineering School Air Force Engineering UniversityXi’an 710038China

Plasma ignition technology has delivered good performance in the aerospace industry. In this study, a pre-combustion plasma jet igniter was designed, and its characteristics were examined from three aspects: the morphology, temperature, and discharge characteristics and process of ignition. Images of the OH distribution were obtained by using an OH Planar Laser-Induced Fluorescence(OH-PLIF) experimental system. Results have shown that the proposed plasma jet had a higher OH concentration, longer length, and larger area than those of a traditional igniter. The stability of discharge of the igniter was improved as the equivalence ratio φ was increased, and reducing gas flow reduced the pulsation of the plasma jet. When the input current was increased from 15A to 35 A, the highest average temperature increased from 5127 K to 7987 K. An increase in the equivalence ratio reduced the region of arc ionization, but expanded the regions of the core combustion reaction and the outer flame. Herein, this study has obtained a deep understanding of the jet and ignition law and developed a new idea for the application of plasma in the ignition field.A pre-combustion plasma jet igniter can significantly improve the efficiency of ignition and shorten the ignition process compared with a traditional igniter.

关键词： Pre-combustion plasma igniter Plasma Jet temperature field Ignition process Arc Flame

Churning loss characteristics of a wet three-phase high-speed reluctance motor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 251-267页

作者： Zhenzhou zhang Mingzhu DAI Chenchen zhang Yi CHEN Bin MENG College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China

With the increasing requirements of electro-hydrostatic actuators(EHAs)for power,volume,and pressure,there is a growing tendency in the industry to combine the motor and pump to form a so-called'motor pump'to improve the *** this paper,a novel structure for a wet three-phase high-speed reluctance motor pump is proposed,which can further improve integration by removing the dynamic seal on the pump shaft,thereby avoiding the problems of dynamic seal wear and oil leakage and improving heat dissipation under high-speed working ***,after the motor is wetted,the churning loss caused by immersion of the rotor in the oil causes additional fluid resistance *** on fundamental fluid mechanics,an analytical model of the churning torque of a wet motor was *** verify the accuracy of the analytical model,a simulation model of churning loss was established based on computational fluid dynamics(CFD),and the churning torque and flow field state were ***,an experimental prototype was designed and manufactured,and a test bench for churning loss was *** oil churning torque was measured at different speeds and *** results from the analytical,simulation,and experimental models agreed *** experimental results validated the analytical model and CFD *** research provides a practical method for calculating the churning loss and serves as guidance for future optimization of churning loss reduction.

关键词： Motor pump Wet motor Churning loss Analytical model Computational fluid dynamics(CFD)

Recent Progress in Improving Rate Performance of Cellulose-Derived Carbon Materials for Sodium-Ion Batteries

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Nano-Micro Letters 2024年第8期16卷 102-147页

作者： Fujuan Wang Tianyun zhang Tian zhang Tianqi He Fen Ran State Key Laboratory of Advanced Processing and Recycling of Non‑Ferrous Metals Lanzhou University of TechnologyLanzhou 730050People’s Republic of China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China School of Mechanical and Electronical Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China

Cellulose-derived carbon is regarded as one of the most promising candidates for high-performance anode materials in sodium-ion batteries;however,its poor rate performance at higher current density remains a challenge to achieve high power density sodium-ion *** present review comprehensively elucidates the structural characteristics of cellulose-based materials and cellulose-derived carbon materials,explores the limitations in enhancing rate performance arising from ion diffusion and electronic transfer at the level of cellulose-derived carbon materials,and proposes corresponding strategies to improve rate performance targeted at various precursors of cellulose-based *** review also presents an update on recent progress in cellulose-based materials and cellulose-derived carbon materials,with particular focuses on their molecular,crystalline,and aggregation ***,the relationship between storage sodium and rate performance the carbon materials is elucidated through theoretical calculations and characterization ***,future perspectives regarding challenges and opportunities in the research field of cellulose-derived carbon anodes are briefly highlighted.

关键词： Cellulose Hard carbon Anode materials Rate performance Sodium-ion batteries

Game theory based finite-time formation control using artificial potentials for tethered space net robot

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Chinese Journal of Aeronautics 2024年第8期37卷 358-372页

作者： Yifeng MA Yizhai zhang Panfeng HUANG Ya LIU Fan zhang The Research Center for Intelligent Robotics School of AstronauticsNorthwestern Polytechnical UniversityXi’an 710072China School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The Tethered Space Net Robot(TSNR)is an innovative solution for active space debris capture and *** large envelope and simple capture method make it an attractive option for this ***,capturing maneuverable debris with the flexible and elastic underactuated net poses significant *** address this,a novel formation control method for the TSNR is proposed through the integration of differential game theory and robust adaptive control in this ***,the trajectory of the TSNR is obtained through the solution of a real-time feedback pursuit-evasion game with a dynamic target,where the primary condition is to ensure the stability of the ***,to minimize tracking errors and maintain a specific configuration,a robust adaptive formation control scheme with Artificial Potential Field(APF)based on a Finite-Time Convergent Extended State Observer(FTCESO)is *** proposed control method has a key advantage in suppressing complex oscillations by a new adaptive law,thus precisely maintaining the ***,numerical simulations are performed to demonstrate the effectiveness of the proposed scheme.

关键词： Game theory Formation control Artificial potential field Relative distance constraint Tethered space net robot(TSNR)