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Science China Chemistry 2024年第5期67卷 1647-1652页

作者： xu Liu Shi wang Siqi Liu Chengfang Liu Xiangchun Li jian Wu Dazhi Li Shihao xu Chongyang Liu Wen-yong Lai State Key Laboratory of Organic Electronics and Information Displays(SKLOEID) Institute of Advanced Materials(IAM)School of Chemistry and Life SciencesNanjing University of Posts&TelecommunicationsNanjing 210023China

Covalent organic frameworks(COFs) are attractive porous crystalline materials with extremely high stability, easy functionalization, and open channels, which are expected to be unique ion conductors/transporters in lithium ion batteries(LIBs). Despite recent advances, low ion conductivity and low transference number, resulting in low charging/discharging rate, low energy density, and short battery life, are the main issues that limit their direct application as solid electrolytes in LIBs. Here, we designed and synthesized a novel polyimide COF, namely, TAPA-PDI-COF, with abundant C=O groups, which has been successfully employed as high-performance solid electrolytes by doping TAPA-PDI-COF and succinonitrile(SN). Both the well-defined nanochannels of COFs and SN confined in the well-aligned channels restricted the free migration of anions, while C=O on COFs and CN groups of SN enhanced Li^(+) transport, thus achieving a high ion conductivity of 0.102 m S cm^(-1)at 80 °C and a high lithium-ion transference number of 0.855 at room temperature. According to density functional theory(DFT)calculations, Li-ion migration mainly adopted in-plane transport rather than the axial pathway, which may be due to the shorter hopping distances in the planar pathway. The results suggest an effective strategy for the design and development of all-solidstate ionic conductors for achieving high-performance LIBs.

关键词： lithium ion batteries(LIBs) covalent organic frameworks(COFs) solid-state ion conductors solid-state electrolytes ion conductivity

Proactive Caching at the Wireless Edge:A Novel Predictive User Popularity-Aware Approach

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1997-2017页

作者： Yunye wan Peng Chen Yunni Xia yong Ma Dongge Zhu xu wang Hui Liu Weiling Li Xianhua Niu Lei xu Yumin Dong College of Computer Science Chongqing UniversityChongqing400044China School of Computer and Software Engineering Xihua UniversityChengdu610039China School of Computer and Information Engineering Jiangxi Normal UniversityNanchang330022China Electric Power Research Institute of State Grid Ningxia Electric Power Co. Ltd.Yinchuan750002China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing400030China School of Computer Science and Technology Beijing Institute of TechnologyBeijing100083China School of Computer Science and Technology Dongguan University of TechnologyDongguan523808China School of Emergency Management Xihua UniversityChengdu610039China College of Computer and Information Science Chongqing Normal UniversityChongqing401331China

Mobile Edge Computing(MEC)is a promising technology that provides on-demand computing and efficient storage services as close to end users as *** an MEC environment,servers are deployed closer to mobile terminals to exploit storage infrastructure,improve content delivery efficiency,and enhance user ***,due to the limited capacity of edge servers,it remains a significant challenge to meet the changing,time-varying,and customized needs for highly diversified content of ***,techniques for caching content at the edge are becoming popular for addressing the above *** is capable of filling the communication gap between the users and content providers while relieving pressure on remote cloud ***,existing static caching strategies are still inefficient in handling the dynamics of the time-varying popularity of content and meeting users’demands for highly diversified entity *** address this challenge,we introduce a novel method for content caching over MEC,i.e.,*** synthesizes a content popularity prediction model,which takes users’stay time and their request traces as inputs,and a deep reinforcement learning model for yielding dynamic caching *** results demonstrate that PRIME,when tested upon the MovieLens 1M dataset for user request patterns and the Shanghai Telecom dataset for user mobility,outperforms its peers in terms of cache hit rates,transmission latency,and system cost.

关键词： Mobile edge computing content caching system average cost deep reinforcement learning collaborative mechanism

Dielectric Constant Calculation of Poly(vinylidene fluoride)Based on Finite Field and Density Functional Theory

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Chinese Journal of Polymer Science 2024年第5期42卷 655-662,I0009页

作者： yong-Zhi Lin Lu-Kun Feng Ya-Dong Li Chao-Fan Chang Cai-Zhen Zhu Ming-Liang wang jian xu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen518055China Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu610041China

In this study,we proposed a novel method that integrates density functional theory(DFT)with the finite field method to accurately estimate the polarizability and dielectric constant of *** approach effectively accounts for the influence of electronic and geometric conformation changed on the dielectric *** validated our method using polyethylene(PE)and polytetrafluoroethylene(PTFE)as benchmark materials,and found that it reliably predicted their dielectric ***,we explored the impact of conformation variations in poly(vinylidene fluoride)(PVDF)on its dielectric constant and *** resulting dielectric constants ofα-andγ-PVDF(3.0)showed excellent agreement with crystalline PVDF in *** findings illuminate the relationship between PVDF’s structural properties and its electrical behavior,offering valuable insights for material design and applications.

关键词： Dielectric constant PVDF Finite field DFT

High-Performance Recyclable Furan-based Epoxy Resin and Its Carbon Fiber Composites with Dense Hydrogen Bonding

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Chinese Journal of Polymer Science 2024年第1期42卷 73-86,I0008页

作者： Chang-Bo Zhao Lu-Kun Feng Hui Xie Ming-Liang wang Bing Guo Zhi-yong xue Cai-Zhen Zhu jian xu Advanced Materials Research Institute North China Electric Power UniversityBejing 102206China Institute of Low-Dimensional Materials Genome Initiative College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu 610041China School of Science and Shenzhen Key Laboratory of Flexible Printed Electronics Technology and Shenzhen Key Laboratory of Advanced Functional Carbon Materials Research and Comprehensive ApplicationHarbin Institute of TechnologyShenzhen 518055China

The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of *** the existence of dynamic chemical bonds in vitrimers often reduces both the thermal and mechanical properties of epoxy resins, it is challenging to produce recyclable epoxy vitrimers with both excellent mechanical properties and good thermal stability. Herein, a monomer 4-(((5-(hydroxymethyl)furan-2-yl)methylene)amino)phenol(FCN) containing furan ring with potential to form high density of hydrogen bonding among repeating units is designed and copolymerized with glycerol triglycidyl ether to yield epoxy resin(FCN-GTE), which intrinsically has dual hydrogen bond networks, dynamic imine structure and resultant high performance. Importantly, as compared to the BPA-GTE, the FCN-GTE exhibits significantly improved mechanical properties owing to the increased density of hydrogen bond network and physical crosslinking interaction. Furthermore, density functional theory(DFT) calculation and in situ FTIR analysis is conducted to decipher the formation mechanism of hydrogen bond network. In addition, the FCN-GTE possesses superior UV shielding, chemical degradation, and recyclability because of the existence of abundant imine bonds. Notably, the FCN-GTE-based carbon fiber composites could be completely recycled in an amine *** study provides a facile strategy for synthesizing recyclable biomass-based high-performance epoxy vitrimers and carbon fiber composites.

关键词： Furan Hydrogen bond network Dynamic Schiff base Carbon fiber composites Recycling

Analysis and optimization of performance parameters of the 220Rn chamber in flow-field mode using computational fluid dynamics method

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Nuclear Science and Techniques 2024年第10期35卷 130-145页

作者： Shao-Hua Hu yong-Jun Ye Zheng-Zhong He De-Tao Xiao Xiang-Yu xu jian-Kai wang Qing-Zhi Zhou School of Nuclear Science and Technology University of South China School of Resources Environment and Safety Engineering University of South China

The impact of the radiation dose produced by222Rn/220Rn and its progeny on human health has garnered increasing interest in the nuclear research field. The establishment of robust, regulatory, and competent220Rn chambers is crucial for accurately measuring radioactivity levels. However, studying the uniformity of the220Rn progeny through experimental methods is challenging, because measuring the concentration of220Rn and its progeny in multiple spatial locations simultaneously and in real time using experimental methods is difficult. Therefore, achieving precise control of the concentration of220Rn and its progeny as well as the reliable sampling of the progeny pose significant challenges. To solve this problem, this study uses computational fluid dynamics to obtain the flow-field data of the220Rn chamber under different wind speeds and progenyreplenishment rates. Qualitative analysis of the concentration distribution of the progeny and quantitative analysis of the progeny concentration and uniformity of the progeny concentration are conducted. The research findings indicated that the progeny concentration level is primarily influenced by wind speed and the progeny-complement rate. Wind speed also plays a crucial role in determining progeny concentration uniformity, whereas the progeny-complement rate has minimal impact on uniformity. To ensure the accuracy of220Rn progeny concentration sampling, we propose a methodology for selecting an appropriate sampling area based on varying progeny concentrations. This study holds immense importance for enhancing the regulation and measurement standards of220Rn and its progeny.

关键词： CFD simulation Progeny Regulatory Thoron

Charge regulation by ferromagnetic metal/LiF spin-polarized interface for high-performance Li metal anodes

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Rare Metals 2024年第3期43卷 995-1005页

作者： Ming-Yang Feng Shuang Zhou Yi-Fang Zhang Ya-Ping wang Chun-Yan Fu jian-Wen Li Yuan-Lang wan Zhi-Jia Zhang yong jiang An-Qiang Pan State Key Laboratory of Powder Metallurgy School of Materials Science and EngineeringCentral South UniversityChangsha410083China State Key Laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Advanced Fibers and Energy StorageSchool of Material Science and EngineeringTiangong UniversityTianjin300387China School of Materials Science and Engineering Hebei University of TechnologyTianjin300130China

The interfacial characteristics of the Li metal anode(LMA)play a crucial role in its overall *** various materials being applied to modify the interface,a comprehensive understanding of their specific mechanisms remains to be ***,we have prepared carbon cloth(CC)frameworks with their surfaces modified using ferromagnetic metal/LiF heterogeneous films(T^(M)-LiF-CC)as the substrate for LMA,which exhibit superior electrochemical *** ferromagnetic Co as a representative example,our study demonstrates that the enhanced performance of Co-LiF-CC,compared to bare CC,is attributed to the spinpolarized interface contributed by the Co/LiF *** and LiF play individual roles in redistributing electrons and Li^(+)to promote homogeneous Li *** nanoparticles play a crucial role in generating strong surface capacitance by storing electrons in spin-split bands,while LiF,with low surface diffusion barriers,ensures fast transportation of Li^(+).The Co-LiF-CC@Li electrodes deliver long lives of 7400 and 3600 h at 1 and 2 mA·cm^(-2)in symmetric cells,respectively;moreover,they enable full batteries with high and durable capacities,particularly when the N/P ratios are low(3.3 or even 1.7).

关键词： Lithium metal anode Interfacial charge Ferromagnetic metal Lithium fluoride Spin polarization

Identification and characterization of camptothecin tailoring enzymes in Nothapodytes tomentosa

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Journal of Integrative Plant Biology 2024年第6期66卷 1158-1169页

作者： Yin Chen jian-Ping Huang yong-jiang wang Meng-Ling Tu Junheng Li Bingyan xu Guoqing Peng Jing Yang Sheng-Xiong Huang State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for Economic Plants and Biotechnology Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

Camptothecin is a complex monoterpenoid indole alkaloid with remarkable antitumor *** that two C-10 modified camptothecin derivatives,topotecan and irinotecan,have been approved as potent anticancer agents,there is a critical need for methods to access other aromatic ringfunctionalized congeners(e.g.,C-9,C-10,etc.).However,contemporary methods for chemical oxidation are generally harsh and low-yielding when applied to the camptothecin scaffold,thereby limiting the development of modified *** herein,we have identified four tailoring enzymes responsible for C-9 modifications of camptothecin from Nothapodytes tomentosa,via metabolomic and transcriptomic *** consist of a cytochrome P450(Nt CPT9H)which catalyzes the regioselective oxidation of camptothecin to 9-hydroxycamptothecin,as well as two methyltransferases(Nt OMT1/2,converting 9-hydroxycamptothecin to 9-methoxycamptothecin),and a uridine diphosphate-glycosyltransferase(Nt UGT5,decorating 9-hydroxycamptothecin to9-β-D-glucosyloxycamptothecin).Importantly,the critical residues that contribute to the specific catalytic activity of Nt CPT9H have been elucidated through molecular docking and mutagenesis *** work provides a genetic basis for producing camptothecin derivatives through metabolic *** will hasten the discovery of novel C-9 modified camptothecin derivatives,with profound implications for pharmaceutical manufacture.

关键词： camptothecin biosynthesis enzymatic assay Nothapodytes tomentosa tailoring enzyme transcriptomic analysis

Unimolecular Self-Assembled Hemicyanine-Oleic Acid Conjugate Acts as a Novel Succinate Dehydrogenase Inhibitor to Amplify Photodynamic Therapy and Eliminate Cancer Stem Cells

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Research 2024年第2期6卷 449-461页

作者： Qiang wang Tian Yang Shiyou Li Chen xu Chong wang Yuxuan Xiong Xing wang jiangling wan Xiangliang Yang Zifu Li National Engineering Research Center for Nanomedicine College of Life Science and Technology.Huazhong University of Science and TechnologyWuhan 430074P.R.China Key Laboratory of Molecular Biophysics of Ministry of Education College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074P.R.China .3Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medical Huazhong University of Science and TechnologyWuhan 430074P.R.China Hubei Engineering Research Center for Biomaterials and Medical Protective Materials Huazhong University of Science and TechnologyWuhan 430074P.R.China Hubei Bioinformatics and Molecular Imaging Key Laboratory College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074P.R.China

Photodynamic therapy with reactive oxygen species production is a prospective treatment to combat cancer stem cells(CSCs).However,the innate drawbacks,including short lifetime and diffusion distance of reactive oxygen species and hypoxia within solid tumors,have become bottlenecks for clinical applications of photodynamic ***,we develop a mitochondria-targeting hemicyanine-oleic acid conjugate(CyOA),which can self-assemble into supramolecular nanoparticles(NPs)without any exogenous *** is also shown for targeting the mitochondrial complex II protein succinate dehydrogenase to inhibit oxidative phosphorylation and reverse tumor hypoxia,resulting in 50.4-fold higher phototoxicity against breast cancer stem cells(BCSCs)compared to SO_(3)-CyOA NPs that cannot target to *** 4T1 and BCSC tumor models,CyOA NPs achieve higher tumor inhibition and less lung metastasis nodules compared to the clinically used photosensitizer *** study develops a self-assembled small molecule that can serve as both oxidative phosphorylation inhibitor and photosensitizer for eradication of CSCs and treatment of solid tumors.

关键词： cyanine oxidative treatment

Enhancing Log Anomaly Detection with Semantic Embedding and Integrated Neural Network Innovations

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Computers, Materials & Continua 2024年第9期80卷 3991-4015页

作者： Zhanyang xu Zhe wang jian xu Hongyan Shi Hong Zhao School of Computer and Software Nanjing University of Information Science and TechnologyNanjing210044China

System logs,serving as a pivotal data source for performance monitoring and anomaly detection,play an indispensable role in assuring service stability and *** this,the majority of existing log-based anomaly detection methodologies predominantly depend on the sequence or quantity attributes of logs,utilizing solely a single Recurrent Neural Network(RNN)and its variant sequence models for *** approaches have not thoroughly exploited the semantic information embedded in logs,exhibit limited adaptability to novel logs,and a single model struggles to fully unearth the potential features within the log *** these challenges,this article proposes a hybrid architecture based on amultiscale convolutional neural network,efficient channel attention and mogrifier gated recurrent unit networks(LogCEM),which amalgamates multiple neural network *** on the superior performance of robustly optimized BERT approach(RoBERTa)in the realm of natural language processing,we employ RoBERTa to extract the original word vectors from each word in the log *** conjunction with the enhanced Smooth Inverse Frequency(SIF)algorithm,we generate more precise log sentence vectors,thereby achieving an in-depth representation of log ***,these log vector sequences are fed into a hybrid neural network,which fuses 1D Multi-Scale Convolutional Neural Network(MSCNN),Efficient Channel Attention Mechanism(ECA),and Mogrifier Gated Recurrent Unit(GRU).This amalgamation enables themodel to concurrently capture the local and global dependencies of the log sequence and autonomously learn the significance of different log sequences,thereby markedly enhancing the efficacy of log anomaly *** validate the effectiveness of the LogCEM model,we conducted evaluations on two authoritative open-source *** experimental results demonstrate that LogCEM not only exhibits excellent accuracy and robustness,but also outperfo

关键词： Deep learning log analysis anomaly detection natural language processing