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Complete kinetic model for esterification reaction of lauric acid with glycerol to synthesize glycerol monolaurate

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Chinese Journal of Chemical Engineering 2024年第6期70卷 211-221页

作者： Han-Qiao Hu Yue Zhang Ming Fan Yong Cai Guang-Wen Chu liang-liang Zhang Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Petrochemical Research Institute China National Petroleum CorporationBeijing 102206China

Glycerol monolaurate(GML)is a widely used industrial chemical with excellent emulsification and antibacterial *** direct esterification of glycerol with lauric acid is the main method to synthesize *** this work,the kinetic process of direct esterification was systematically studied using p-toluenesulfonic acid as catalyst.A complete kinetic model of consecutive esterification reaction has been established,and the kinetic equation of acid catalysis was *** isomerization reactions of GML and glycerol dilaurate were *** was found that the reaction was an equilibrium reaction and the reaction rate was faster than the esterification *** kinetic equations of the consecutive esterification reaction were obtained by experiments as k_(1)=(276+92261Xcat)exp(-37720/RT)and k_(2)=(80+4413Xcat)exp(-32240/RT).The kinetic results are beneficial to the optimization of operating conditions and reactor design in GML production process.

关键词： Glycerol monolaurate p-Toluenesulfonic acid Esterification Kinetics Mass transfer

The chlorine evolution reaction promoted by organocatalysts with amide functional groups

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Science China Chemistry 2024年第3期67卷 749-750页

作者： Lan Zhao liang-Nian He State Key Laboratory and Institute of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071China

Since the nineteenth century, the chlor-alkali process entails the electrochemical oxidation of sodium chloride solutions to Cl_(2) by the chlorine evolution reaction(CER) and the simultaneous production of sodium hyd... 详细信息

关键词： chlorine hydroxide promoted

Big Theta Equals Small Theta Generically

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Acta Mathematica Sinica,English Series 2024年第3期40卷 717-730页

作者： Rui CHEN Jia liang ZOU Institute for Advanced Study in Mathmatics Zhejiang UniversityHangzhou 310058P.R.China Department of Mathematics University of Michigan530 Church StAnn ArborMI 48109USA

In this paper we consider the theta correspondence over a non-Archimedean local *** the homological method and the theory of derivatives,we show that under a mild condition the bigtheta lift is irreducible.

关键词： Theta correspondence derivatives

Event-triggered predefined-time control for full-state constrained nonlinear systems: A novel command filtering error compensation method

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Science China(Technological Sciences) 2024年第9期67卷 2867-2880页

作者： PAN YingNan CHEN YiLin liang HongJing College of Control Science and Engineering Bohai UniversityJinzhou 121013China School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Laboratory of Electromagnetic Space Cognition and Intelligent Control Beijing 100089China

In this paper, a command filter-based adaptive fuzzy predefined-time event-triggered tracking control problem is investigated for uncertain nonlinear systems with time-varying full-state constraints. By designing a sliding mode differentiator, the inherent computational complexity problem within the predefined-time backstepping framework is solved. Different from the existing command filter-based finite-time and fixed-time control strategies that the convergence time of the filtering error is adjusted through the system initial value or numerous parameters, a novel command filtering error compensation method is presented,which tunes one control parameter to make the filtering error converge in the predefined time, thereby reducing the complexity of design and analysis of processing the filtering error. Then, an improved event-triggered mechanism(ETM) that builds upon the switching threshold strategy, in which an inverse cotangent function is designed to replace the residual term of the ETM,is proposed to gradually release the controller's dependence on the residual term with increasing time. Furthermore, a tan-type nonlinear mapping technique is applied to tackle the time-varying full-state constraints problem. By the predefined-time stability theory, all signals in the uncertain nonlinear systems exhibit predefined-time stability. Finally, the feasibility of the proposed algorithm is substantiated through two simulation results.

关键词： predefined-time control command filtering error compensation method event-triggered mechanism time-varying full-state constraints uncertain nonlinear systems

The higher-order topological pumping explored in the 2D acoustic crystal

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 127-133页

作者： Yanqiu Wang Bin liang Jianchun Cheng Key Laboratory of Modern Acoustics Ministry of EducationInstitute of AcousticsDepartment of PhysicsNanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

The topological pumping has been instrumental in advancing our understanding of topological phase transitions in various physical systems,which can be extended to uncover intriguing higher-order topological phases in the lower-dimensional ***,we propose a theoretical exploration of topological dipole pumping on an acoustic square superlattice by cyclically modulating intracell couplings,which shares the topological nature of an extended three-dimensional system with chiral hinge *** the multipole chiral numbers,we characterize the higher-order topological phases that arise during the *** evolution of topological phase transitions is verified by numerical simulations and shows corner states are transferred across the *** findings can inspire the construction of chiral hinge states in artificial crystals,opening up new possibilities for the design of devices allowing the unidirectional propagation of sound.

关键词： topological phases of matter Thouless pumping acoustic metamaterial

Polyelectrolyte Complexes and Coacervates Formed by De novo-Designed Peptides and Oligonucleotide

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Chinese Journal of Polymer Science 2024年第9期42卷 1333-1340,I0007页

作者： Tian-Hao Ren De-Hai liang Beijing National Laboratory for Molecular Sciences Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

The liquid-liquid phase separation of biopolymers in living cells contains multiple interactions and occurs in a dynamic *** the regulation mechanism is still a *** this work,we designed a series of peptides(XXLY)_(6)SSSGSS and studied their complexation and coacervation behavior with single-stranded ***“X”and“Y”are varied to combine known amounts of charged and non-charged amino acids,together with the introduction of secondary structures and pH *** show that the electrostatic interaction,which is described as charge density,controls both the strength of complexation and the degree of chain relaxation,and thus determines the growth and size of the *** hydrophobic interaction is prominent when the charges are ***,the secondary structures of peptides exhibit profound effect on the morphology of the phases,such as solid phase to liquid phase *** study gains insight into the phase separation under physiological *** is also helpful to create coacervates with desirable structures and functions.

关键词： Polyelectrolyte complex Coacervate Peptides Secondary structure Electrostatic interaction

A Fully-Integrated Memristor Chip for Edge Learning

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Nano-Micro Letters 2024年第9期16卷 123-127页

作者： Yanhong Zhang liang Chu Wenjun Li School of Electronics and Information Hangzhou Dianzi UniversityHangzhou 310018People’s Republic of China

It is still challenging to fully integrate computing in memory chip as edge learning *** recent work published on Science,a fully-integrated chip based on neuromorphic memristors was developed for edge learning as artificial neural networks with functionality of synapses,dendrites,and somas.A crossbar-array memristor chip facilitated edge learning including hardware realization,learning algorithm,and cycle-parallel sign-and threshold-based learning(STELLAR)*** motion control and demonstration platforms were executed to improve the edge learning ability for adapting to new scenarios.

关键词： Computing in memory Edge learning Fully-integrated chip

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基于空调负荷数据挖掘的配电网扩展规划方法

电力建设 2021年第11期42卷 100-107页

作者：苏宁李笑彤梁惠施贡晓旭吕风波席嫣娜齐步洋国网北京市电力公司经济技术研究院北京市100055 清华四川能源互联网研究院成都市610213 清华大学电机工程与应用电子技术系北京市100084

针对配电网规划领域负荷数据挖掘问题,基于实际数据,应用隐马尔科夫模型算法,建立空调负荷挖掘及需求侧响应评估模型,将空调负荷从用电数据中分离,准确描述需求侧响应限值。以配电系统折算到年的总成本最小为目标函数,提出扩展规划模型... 详细信息

针对配电网规划领域负荷数据挖掘问题,基于实际数据,应用隐马尔科夫模型算法,建立空调负荷挖掘及需求侧响应评估模型,将空调负荷从用电数据中分离,准确描述需求侧响应限值。以配电系统折算到年的总成本最小为目标函数,提出扩展规划模型并进行求解,最后通过IEEE 33节点算例对模型有效性进行验证。结果表明,所提数据挖掘算法能够有效挖掘用户需求侧响应潜力,有利于优化配电网规划方案,降低系统总成本,延缓配电网扩展投资,提高配电系统整体经济性,对配电网规划具有重要的现实意义和作用。

关键词：数据挖掘需求侧响应配电网规划

Divalent anion intercalation and etching-hydrolysis strategies to construct ultra-stable electrodes for seawater splitting

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Science China Chemistry 2024年第2期67卷 687-695页

作者： Jiajia Lu Yang Liu Han-Pu liang Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao266101China Henan Provincial Key Laboratory of Nanocomposites and Applications Institute of Nano-Structured Functional MaterialsHuanghe Science and Technology CollegeZhengzhou450006China School of Materials Science and Engineering Henan Normal UniversityXinxiang453007China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China Shandong Energy Institute Qingdao266101China

Developing stable electrodes for seawater splitting remains a great challenge due to the detachment of catalysts at a large operating current and severe anode corrosion caused by ***,divalent anion intercalation and etching-hydrolysis strategies are deployed to synthesize the ultra-stable anode,dendritic Fe(OH)_(3) grown on Ni(SO_4)_(0.3)(OH)_(1.4)–Ni(OH)_(2).Experimental results reveal that the anode exhibits good activity and excellent stability in alkaline simulated *** 500 h,the current density operated at 1.72 V remains 99.5%,about 210 m A cm^(-2).The outstanding stability originates from the etchinghydrolysis strategy,which strengthens the interaction between the catalyst and the carrier and retards thus the detachment of catalysts at a large current ***,theoretical simulations confirm that the intercalated divalent anions,such as SO_4^(2-) and CO_(3)^(2-),can weaken the adsorption strength of chlorine on the surface of catalysts and hinder the coupling and hybridization between chlorine and nickel,which slows down the anode corrosion and improves catalytic ***,the twoelectrode system shows the remarkable 95.1% energy efficiency at 2,000 A m-2and outstanding stability in 6 mol L^(-1) KOH +seawater at 80 ℃.

关键词： seawater splitting stability divalent anion intercalation etching-hydrolysis

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