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Role of methoxy and C_(α)-based substituents in electrochemical oxidation mechanisms and bond cleavage selectivity of β-O-4 lignin model compounds

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Green Energy & Environment 2024年第1期9卷 114-125页

作者： yang zhou Qiang Zeng Hongyan He Kejia wu Fuqiao Liu Xuehui Li School of Chemistry and Chemical Engineering The Guangdong Provincial Key Laboratory of Green Chemical Product TechnologyState Key Laboratory of Pulp and Paper EngineeringSouth China University of TechnologyGuangzhouGuangdong510640China CAS Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China

In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.

关键词： Lignin model compounds β-O-4 dimers Electrochemical oxidation Oxidation mechanisms Substituent effect

Plasma-etching on monolithic MOFs-based MIM filter boosted chemical sensing

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Nano Research 2024年第4期17卷 2800-2807页

作者： Jianxi Liu Li Feng Zhihuan Li yang wu Feng zhou Yadong Xu Research&Development Institute Northwestern Polytechnical University in ShenzhenShenzhen 518057China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Yantai Zhongke Research Institute of Advanced Materials and Green Chemical Engineering Shandong Laboratory of Advanced Materials and Green Manufacturing at YantaiYantai 264006China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Metal-insulator-metal(MIM)cavity as a lithography-free structure to control light transmission and reflection has great potential in the field of optical ***,the dense top metal layer of the MIM prohibits any external medium from entering the dielectric insulation layer,which limits the application of the cavity in the sensing ***,we demonstrate a series of monolithic metal-organic frameworks(MOFs)based MIM cavities,which are treated by plasma etching to provide channels for chemical diffusion and to advance *** modulate the bandwidth of the MIM filters by controlling the MOF thickness as insulator *** plasma-etching is applied to build channels on the top metal layer without altering their saturation and brightness for chemical sensing *** etching time regulates the number and size of channels on the top metal *** behavior is demonstrated on the plasma-etched MOFs-based MIM cavity when external chemicals diffuse in the *** addition,we generate patterned structure of the MOFs-based MIM cavity via plasma-mask method,which can transfer to different substrates and produce a controllable structure color change for chemical *** MIM cavity may promote the advancement and applications of structural color in security imaging,color display,information anticounterfeiting,and color printing.

关键词： metal-organic frameworks(MOFs) spin-coating metal-insulator-metal filter patterns sensing

Sensing Matrix Optimization for Random Stepped-Frequency Signal Based on Two-Dimensional Ambiguity Function

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Chinese Journal of Electronics 2024年第1期33卷 161-174页

作者： Mingjiu LYU Hao CHEN Jun yang Xia wu Ming zhou Xiaoyan MA Radar NCO School Air Force Early Warning Academy Department of Early Warning Technology Air Force Early Warning Academy

Compressive sensing technique has been widely applied to achieve range-Doppler reconstruction of high frequency radar by utilizing sparse random stepped-frequency(SRSF) signal, which can suppress the complex electromagnetic interference and greatly reduce the coherent processing interval. An important way to improve the performance of sparse signal reconstruction is to optimize the sensing matrix(SM). However, the existing research on the SM optimization needs to design a measurement matrix with superior performance, which needs a large amount of computation and does not consider the influence of the waveform parameters design. In order to improve the superior reconstruction performance, a novel SM optimization approach for SRSF signal is proposed by using two-dimensional ambiguity function(TDAF) in this paper. Firstly, based on the two-dimensional sparse reconstruction model of the SRSFs, the internal relationship between the waveform parameters and the SM was derived. Secondly, the SM optimization problem was directly transformed into the waveform design of SRSFs. Furthermore, on the basis of analyzing the relationship between the mutual coherence matrix of SM and the TDAF matrix of SRSFs, the purpose of optimizing the SM can be achieved by designing the TDAF of the SRSFs. Based on this analysis, a sparse waveform optimization method with joint constraints of maximum and mean sidelobes of the TDAF by using the genetic algorithm was derived. Compared with the traditional SM optimization method, our method not only avoids generating a new measurement matrix, but also further reduces the complexity of the waveform optimization. Simulation experiments verified the effectiveness of the proposed method.

关键词： Correlation Computational modeling Electromagnetic interference Optimization methods Signal reconstruction High frequency radar Sensors

Enhancement of liquid-liquid micromixing performance in curved capillary microreactor by generation of Dean vortices

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Chinese Journal of Chemical Engineering 2024年第4期68卷 76-82页

作者： Shaoyun wu Zhuang Ma Zichi yang Suying Zhao Caijin zhou Huidong Zheng Fujian Engineering Research Center of Advanced Manufacturing Technology for Fine Chemicals College of Chemical EngineeringFuzhou UniversityFuzhou 350108China Qingyuan Innovation Laboratory Quanzhou362114China

Micromixing efficiency is an important parameter for evaluating the multiphase mass transfer performance and reaction efficiency of *** this work,the novel curved capillary reactor with different shapes was designed to generate Dean flow,which was used to enhance the liquid-liquid micromixing *** Villermaux-Dushman probe reaction was employed to characterize the micromixing performance in different curved capillary *** effects of experiment parameters such as liquid flow rate,inner diameter,tube length,and curve diameter on micromixing performance were systematically *** the optimal conditions,the minimum value of the segmentation factor XS was *** was worth noting that at the low Reynolds number(Re<30),the change of curved shape on the capillary microreactor can significantly improve the micromixing performance with XS reduced by 37.5%.Further,the correlations of segment index XS with dimensionless factor such as Reynolds number or Dean number were developed,which can be used to predict the liquid-liquid micromixing performance in capillary microreactors.

关键词： Microreactor Process intensification Micromixing performance Dean flow

Advances of Electrochemical and Electrochemiluminescent Sensors Based on Covalent Organic Frameworks

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Nano-Micro Letters 2024年第2期16卷 395-422页

作者： Yue Cao Ru wu Yan‑Yan Gao yang zhou Jun‑Jie Zhu Key Laboratory for Organic Electronics and Information Displays(KLOEID)and Institute of Advanced Materials(IAM) Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023People’s Republic of China State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023People’s Republic of China

Covalent organic frameworks(COFs),a rapidly developing category of crystalline conjugated organic polymers,possess highly ordered structures,large specific surface areas,stable chemical properties,and tunable pore *** the first report of boroxine/boronate ester-linked COFs in 2005,COFs have rapidly gained popularity,showing important application prospects in various fields,such as sensing,catalysis,separation,and energy *** them,COFs-based electrochemical(EC)sensors with upgraded analytical performance are arousing extensive *** this review,therefore,we summarize the basic properties and the general synthesis methods of COFs used in the field of electroanalytical chemistry,with special emphasis on their usages in the fabrication of chemical sensors,ions sensors,immunosensors,and ***,the emerged COFs in the electrochemiluminescence(ECL)realm are thoroughly covered along with their preliminary ***,final conclusions on state-of-the-art COFs are provided in terms of EC and ECL sensors,as well as challenges and prospects for extending and improving the research and applications of COFs in electroanalytical chemistry.

关键词： Covalent organic frameworks Electrochemistry Electrochemiluminescence Sensors

Injection of a Self-propelled Polymer into a Small Circular Cavity

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Chinese Journal of Polymer Science 2024年第6期42卷 886-894页

作者： Chao Wang Yan-Li zhou Xiao yang Fan wu Meng-Bo Luo Department of Physics Taizhou UniversityTaizhou318000China Department of Physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active Polymer Injection Dynamics Simulation

Backtracking Routing Mechanism for Improving Link Failure Recovery

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wuhan University Journal of Natural Sciences 2007年第3期12卷 462-466页

作者： wu Jing zhou Jianguo yang Jianfeng YAN Puliu JIANG Hao School of Electronic Information Wuhan University Wuhan 430072 Hubei China

Failure-insensitive routing is a good mechanism to avoid packet dropping and disconnection of forwarding when some links fail, but multiple failure links may bring routing loop for the mechanism. Backtracking routing algorithm based on inverse shortest path tree rooted at destination is presented. The feasible restoration routing is obtained through searching from the start of the failure link and tracing back to the leaves of the shortest path tree with the destination as the root. The packets are forwarded from the mounted point with smaller sequence to the mount point with bigger sequence to decrease the possible of loop in case of multi-failures. The simulations and analysis indicate that backtracking routing algorithm improves the network survivability especially for large network, at the cost of the computation complexity in the same order as failure insensitive routing.

关键词： failure insensitive routing (FIR) shortest path tree (SPT) backtracking routing mechanism network survivability network usability

Sulphur-template method for facile manufacturing porous silicon electrodes with enhanced electrochemical performance

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Chinese Chemical Letters 2024年第8期35卷 433-436页

作者： Peng zhou Ziang Jiang yang Li Peng Xiao Feixiang wu Powder Metallurgy Research Institute School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083China

Sulphur(S)-template method based on conventional slurry-casting method has been developed to pro-duce porous silicon(Si)*** facile fabrication technology is suitable for current production line and expected to be widely applied to various electrode materials under large volume change during ***,S particles as template agent are mixed with active material Si,carbon conductor and binder forming uniform *** casting and drying,the electrodes are immersed in carbon disul-fide solution to remove S particles rapidly,generating pores in-situ at the original position of S *** analysis shows that the pores inside electrodes are able to shorten lithium ion diffusion paths,reduce normal expansion rate and decrease formation of cracks in the Si electrode(2 mg_(Si)/cm^(2)),demonstrating a reversible capacity of 951 mAh/g at 0.5 A/g after 100 cycles(with a capacity retention of 99.5%)and a capacity of-826 mAh/g at 2 A/g.

关键词： Sulphur-template Porous electrodes Silicon anodes Low volume expansion Lithium-ion batteries

Micromechanism and mathematical model of stress sensitivity in tight reservoirs of binary granular medium

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Petroleum Science 2024年第3期21卷 1780-1795页

作者： Jian-Bang wu Sheng-Lai yang Qiang Li Kun yang Can Huang Dao-Ping Lv Wei zhou State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China Laboratoire de G eologie Ecole Normale Sup erieure/CNRS UMR8538PSL Research UniversityParis75005France Research Institute of Exploration and Development Xinjiang Oilfield CompanyKaramay834000XinjiangChina

Research on reservoir rock stress sensitivity has traditionally focused on unary granular structures,neglecting the binary nature of real reservoirs,especially tight *** the stresssensitive behavior and mathematical characterization of binary granular media remains a challenging *** this study,we conducted online-NMR experiments to investigate the permeability and porosity evolution as well as stress-sensitive control mechanisms in tight sandy conglomerate *** results revealed stress sensitivity coefficients between 0.042 and 0.098 and permeability damage rates ranging from 65.6%to 90.9%,with an average pore compression coefficient of 0.0168—0.0208 MPa ***-scale compression occurred in three stages:filling,compression,and compaction,with matrix pores playing a dominant role in pore *** stress sensitivity of binary granular media was found to be influenced by the support structure and particle *** stress sensitivity was associated with small fine particle size,high fines content,high uniformity coefficient of particle size,high plastic deformation,and low Young's ***-supported samples exhibited a high irreversible permeability damage rate(average=74.2%)and stress sensitivity coefficients(average=0.089),with pore spaces more *** contrast,grain-supported samples showed low stress sensitivity coefficients(average=0.021)at high stress *** on the experiments,we developed a mathematical model for stress sensitivity in binary granular media,considering binary granular properties and nested interactions using Hertz contact deformation and Poiseuille *** describing the change in activity content of fines under stress,we characterized the non-stationary state of compressive deformation in the binary granular structure and classified the reservoir into three *** model was applied for production prediction using actual data from the Mahu reservoir in China,showing that the e

关键词： Stress sensitivity Binary granular medium Tight reservoir Online-NMR Reservoir energy retention rate