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Chinese Journal of Chemistry 2022年第19期40卷 2305-2312页

作者： Yang Zhou yangkang Fu Mao Chen Department of Macromolecular Science State Key Laboratory of Molecular Engineering of PolymersFudan UniversityShanghai200438 China

Molecular weight distribution(MWD)is fundamental for polymer analysis,which influences many important properties of polymeric materials.In this work,we demonstrate the development of a computer-aided droplet-flow system that combines photo-mediated reversible-deactivation radical polymerization(RDRP)and chain transfer agent(CTA)diffusion strategy to enable facile MWD control for the first time.Synthetic advantages of this photo-flow polymerization allow controlled chain-growth to yield a variety of polymers of tunable MWDs in a broad range(Ð≈1.1—1.9)with predetermined molecular weights(Mn≈4—30 kDa)and good chain-end fidelity.Notably,the computer-aided platform has streamlined an automatic and high-throughput pathway to prepare polymer libraries of tunable MWDs.For copolymers,chemical compositions could be readily regulated besides MWDs with the droplet-flow platform.We believe that this work should be attractive for polymer engineering,and informative to create more flow polymerization techniques toward on-demand control of diverse polymer characters.

关键词： Photocatalysis Copolymerization Synthetic methods Molecular weight distribution Flow chemistry

Computer-Aided Living Polymerization Conducted under Continuous-Flow Conditions

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Chinese Journal of Chemistry 2022年第2期40卷 285-296页

作者： Zeyu Wang Yang Zhou Mao Chen State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China

Continuous-flow techniques have promoted the development of synthetic chemistry due to advantages such as outstanding mass/heat transfer,on-demand scalability,improved safety,precise regulation on reaction parameters,etc.Recently,the combination of flow polymerization with computer scienee has gained considerable interests,leading to a variety of cutting-edge synthetic techniques.This review summarizes emerging achievements realized via the integration of computer science and living flow polymerizations,including 1)high-throughput living polymerizations in flow,2)programmable regulations of dispersity profile,se-que nee and topology for polymers,3)modular desig n with on line mon itori ng,as well as 4)self-optimized living polymerizati ons in flow.We expect that this summary will furnish informative kno wledge to scie ntists in related directions and in spire new ideas to further empower on-demand polymer engineering with modern techniques.

关键词： Polymers Synthetic methods Polymerization Flow chemistry Computer-aided synthesis

Bimetallic Ni-Mo nitride@C_(3)N_(4) for highly active and stable water catalysis

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Frontiers of Materials Science 2022年第3期16卷 181-191页

作者： Xinping LI Min zhou Zhuoxun YIN Xinzhi MA Yang Zhou College of Chemistry and Chemical Engineering Qiqihar UniversityQiqihar 161006China School of Physics and Electronic Engineering Harbin Normal UniversityHarbin 150025China College of Science Qiqihar UniversityQiqihar 161006China

Non-noble metal electrocatalysts for water cracking have excellent pro-spects for development of sustainable and clean energy.Highly efficient electrocatalysts for the oxygen evolution reaction(OER)are very important for various energy storage and conversion systems such as water splitting devices and metal-air batteries.This study prepared a NiMo4@C_(3)N_(4) catalyst for OER and hydrogen evolution reaction(HER)by simple methods.The catalyst exhibited an excellent OER activity based on the response at a suitable temperature.To drive a current density of 10 mA-cm^(-2) for OER and HER,the overpotentials required for NiMo4@C_(3)N_(4)-800(prepared at 800℃)were 259 and 118 mV,respectively.A two-electrode system using NiMo4@C_(3)N_(4)-800 needed a very low cell potential of 1.572 V to reach a current density of 10 mA-cm^(-2).In addition,this catalyst showed excellent durability after long-term tests.It was seen to have good catalytic activity and broad application prospects.

关键词： stability oxygen reduction reaction watersplitting electrocatalyst

Uncertainty quantification of predicting stable structures for high-entropy alloys using Bayesian neural networks

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Journal of Energy Chemistry 2023年第6期81卷 118-124,I0005页

作者： Yonghui zhou Bo yang School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

High entropy alloys(HEAs)have excellent application prospects in catalysis because of their rich components and configuration space.In this work,we develop a Bayesian neural network(BNN)based on energies calculated with density functional theory to search the configuration space of the CoNiRhRu HEA system.The BNN model was developed by considering six independent features of Co-Ni,Co-Rh,CoRu,Ni-Rh,Ni-Ru,and Rh-Ru in different shells and energies of structures as the labels.The root mean squared error of the energy predicted by BNN is 1.37 me V/atom.Moreover,the influence of feature periodicity on the energy of HEA in theoretical calculations is discussed.We found that when the neural network is optimized to a certain extent,only using the accuracy indicator of root mean square error to evaluate model performance is no longer accurate in some scenarios.More importantly,we reveal the importance of uncertainty quantification for neural networks to predict new structures of HEAs with proper confidence based on BNN.

关键词： Uncertainty quantification High-entropy alloys Bayesian neural networks Energy prediction Structure screening

Efficient bifunctional catalysts of CoSe/N-doped carbon nanospheres supported Pt nanoparticles for methanol electrolysis of hydrogen generation

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Nano Research 2022年第10期15卷 8936-8945页

作者： Yang Zhou Qiaowei Wang Xinlong Tian Ligang Feng School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan Provincial Key Lab of Fine ChemistrySchool of Chemical Engineering and TechnologyHainan UniversityHaikou 570228China

Methanol electrolysis is significant but challenging as an energy-saving technique for electrochemical hydrogen production.Herein,we demonstrated a novel and efficient bifunctional catalyst of CoSe/N-doped carbon nanospheres supported Pt nanoparticles for hydrogen generation via methanol electrolysis;high catalytic performance for both methanol oxidation(MOR)and hydrogen evolution(HER)was observed benefitting from the effective interaction of metal and support effect as well as the oxophilic characteristics of cobalt selenide.Theoretical calculation disclosed the increased charge density of Pt induced by the CoSe/NC support has a bifunctional ability for optimizing the H*adsorption energy for hydrogen evolution reaction and weakening the CO adsorption energy of methanol oxidation reaction.Specifically,the largely improved CO-tolerance ability was observed in the CO-stripping technique,where about 90 mV less of the peak potential for CO oxidation than that of Pt/C catalyst was observed,resulting from a strong electronic effect as indicated by the spectroscopic analysis.The peak current density of 84.2 mA·cm^(–2) was found for MOR,which was about 3.1 times higher than that of Pt/C;and a low overpotential of 32 mV was required to reach 10 mA·cm^(–2) for HER in 0.5 mol·L^(–1) H_(2)SO_(4) with 1.0 mol·L^(–1) CH3OH.When serviced as both anode and cathode catalyst in a methanol electrolyzer,a low cell potential of 0.67 V to offer 10 mA cm^(-2) was obtained,about 170 mV less than that of Pt/C catalyst;moreover,it was 1.1 V lower than that of water-splitting(1.77 V),indicating a promising energy-saving technique for hydrogen generation.They also showed very good catalytic stability and anti-poisoning ability during the catalysis process.This work would help understand the metal-support interaction for hydrogen generation vis methanol electrolysis.

关键词： bifunctional electrocatalyst methanol electrolysis hydrogen evolution reaction Pt-based catalysts metal-organic frameworks

Distributed Event-Triggered Tracking Control of Heterogeneous Discrete-Time Multi-Agent Systems with Unknown Parameters

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Journal of Systems Science & Complexity 2022年第4期35卷 1330-1347页

作者： yang Ruohan zhou Deyun School of Electronics and Information Northwestern Polytechnical UniversityXi’an710072China

In this paper,a novel design framework is developed to solve the cooperative tracking problem of heterogeneous discrete-time multi-agent systems with unknown agent parameters and directed communication topologies.First,a distributed event-triggered observer is developed to handle the heterogeneity of the multi-agent systems.An event-triggering mechanism is proposed to reduce the amount of data transmission between neighboring agents.Then,based on the proposed observer,a discrete-time distributed model reference adaptive controller is presented to deal with the unknown parameters of the multi-agent systems.It is shown that by using the proposed observer and the model reference adaptive controller,the proposed design framework could achieve output tracking of the unknown multi-agent systems for any communication graph containing a directed spanning tree.Finally,an example is presented to illustrate the effectiveness of the proposed controller.

关键词： Adaptive control cooperative control distributed control event-triggered control heterogeneous multi-agent systems

Effect of feeding parameters on ingot segregation and shrinkage pore in vacuum arc remelting

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Journal of Iron and Steel Research(International) 2023年第6期30卷 1268-1278页

作者： Dong-bin Jiang Fu-zhong yang Jian Zhang Yang Zhou Li-feng Zhang School of Metallurgy and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Chengdu Advanced Metal Materials Industrial Technology Institute Chengdu 610303SichuanChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

The feeding parameters in the final stage of vacuum arc remelting process obviously affect the solute segregation and shrinkage pore depth.Coupled with the electromagnetic field,fluid flow,and solute transport,a numerical model was built to investigate the effect of feeding parameters on the ingot solidification phenomena.The Nb segregation and shrinkage pore depth in the solidified ingot were measured.The results show that the liquid moves along the solidification front and the vertex flow is formed in the liquid pool,which promotes solute transport.In the solidified ingot,the Nb segregation in the lower part is negative,while that in the upper part is positive.With the differential electrode applied,the positive segregation is slightly reduced but the segregation distribution remains unchanged.As the feeding current decreases,the positive segregation zone moves toward the ingot top surface,due to the final solidification position moving upward.With the feeding time extended,the positive segregation moves to the top surface and the shrinkage pore depth is reduced.As the feeding time is set at 12 min,the shrinkage pore depth can be reduced to 21 mm.

关键词： Vacuum arc remelting Feeding parameter Macrosegregation Shrinkage pore Solidification

A physical layer security scheme for full-duplex communication systems with residual self-interference and non-eavesdropping CSI

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Digital Communications and Networks 2021年第3期7卷 352-361页

作者： Weijia Lei Yang Zhou Xiuzhen Lin School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

We discuss the physical layer security scheme in the Full-Duplex(FD)MIMO point-to-point two-way communication system with residual self-interference,in which legitimate nodes send confidential information and null space Artificial Noise(AN)while receiving information.Because the Channel State Information(CSI)of the eavesdropper is unavailable,we optimize the covariance matrices of the information signal as well as the allocation of the antenna for transmitting and receiving to minimize the signal power consumption under the target rate constraint.As a result,the power of AN is maximized within the limit of total power,so the interception capability of the eavesdropper is suppressed as much as possible.Since self-interference cannot be completely eliminated,the optimization process of one legitimate node depends on the optimization result of the other.By substituting self-interference power in the secrecy rate formula with its average value,the joint optimization process at the two nodes is transformed into two separate and solvable optimization processes.Then,the Water-Filling Algorithm(WFA)and bisection algorithm are used to get the optimal covariance matrices of the signal.Furthermore,we derive the theoretical lower bound of ergodic achievable secrecy rate under rayleigh channels to evaluate the performance of the scheme.The simulation results show that the theoretical derivation is correct,and the actual achievable rate is very close to the target rate,which means that the approximation in the optimization is feasible.The results also show that secrecy transmission can be realized because a considerable secrecy rate can be achieved.

关键词： Physical layer security Full-duplex Self-interference Eavesdropping CSI Multi-antenna

Peripheral and central control of obesity by primary cilia

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Journal of Genetics and Genomics 2023年第5期50卷 295-304页

作者： Yue Wu Jun zhou Yunfan yang Center for Cell Structure and Function Shandong Provincial Key Laboratory of Animal Resistance BiologyCollaborative Innovation Center of Cell Biology in Universities of ShandongCollege of Life SciencesShandong Normal UniversityJinanShandong 250014China State Key Laboratory of Medicinal Chemical Biology Haihe Laboratory of Cell EcosystemCollege of Life SciencesNankai UniversityTianjin 300071China Department of Cell Biology School of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong 250012China

Primary cilia are hair-like structures that protrude from the cell surface.They are capable of sensing external cues and conveying a vast array of signals into cells to regulate a variety of physiological activities.Mutations in cilium-associated genes are linked to a group of diseases with overlapping clinical manifestations,collectively known as ciliopathies.A significant proportion of human ciliopathy cases are accompanied by metabolic disorders such as obesity and type 2 diabetes.Nevertheless,the mechanisms through which dysfunction of primary cilia contributes to obesity are complex.In this review,we present an overview of primary cilia and highlight obesity-related ciliopathies.We also discuss the potential role of primary cilia in peripheral organs,with a focus on adipose tissues.In addition,we emphasize the significance of primary cilia in the central regulation of obesity,especially the involvement of ciliary signaling in the hypothalamic control of feeding behavior.This review therefore proposes a framework of both peripheral and central regulation of obesity by primary cilia,which may benefit further exploration of the ciliary role in metabolic regulation.

关键词： Ciliopathy Metabolism Adipose tissue Adipogenesis Hypothalamus

Molecular dynamics study of water diffusion in an amphiphilic block copolymer with large difference in the blocks＇ glass transition temperatures

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Frontiers of Chemical Science and Engineering 2017年第3期11卷 440-447页

作者： Yang Zhou Phillip Choi Department of Chemical and Materials Engineering University of Alberta Edmonton Edmonton AB T6G 1H9 Canada

Isothermal-isobaric molecular dynamics simu- lation was used to study the diffusion mechanism of water in polyurethane-block-poly（N-isopropyl acrylamide）（PU- block-PNIPAm） with a hydrophobic PU/hydrophilic PNIPAm mass ratio of 1.4 to 1 at 298 K and 450 K. Here, the experimental glass transition temperature （Tg） of PU is 243 K while that of PNIPAm is 383 K. Different amounts of water up to 15 wt-% were added to PU-block- PNIPAm. We were able to reproduce the specific volumes and glass transition temperatures （250 K and 390 K） of PU- block-PNIPAm. The computed self-diffusion coefficient of water increased exponentially with increasing water concentration at both temperatures （i.e., following the free volume model of Fujita）. It suggested that water diffusion in PU-block-PNIPAm depends only on its fractional free volume despite the free volume inhomo- geneity. It is noted that at 298 K, PU is rubbery while PNIPAm is glassy. Regardless of temperature, radial distribution functions showed that water formed clusters with sizes in the range of 0.2-0.4 nm in PU-block- PNIPAm. At low water concentrations, more clusters were found in the PU domain but at high water concentrations, more in the PNIPAm domain. It is believed that water molecules diffuse as clusters rather than as individual molecules.

关键词： molecular dynamics simulation amphiphilic block copolymer free volume water diffusivity fujita model