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Synthesis of Hydroxystilbene Derivatives and their Antioxidant Activity by DPPH Method

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Chemical Research in Chinese Universities 2006年第6期22卷 742-746页

作者： LI Yue-qing SONG qi-ling chen Ping-ping ZHAO Wei-jie WANG Shi-sheng State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 116012 P. R. China

Five hydroxystilbene derivatives were synthesized and their structures were determined using high-resolution mass spectrometry, ^1H NMB, and IR. In this study, the antioxidant activities of eight hydroxystilbenes （five synthesized hydroxystilbene derivatives and three other compounds） were evaluated with the free radiced scavenging model 1,1-diphenyl-2-picrylhydraxyl. It was observed that there exists a very significant linear rehtionship between the reciprocal of the EC50 value of each of the compounds and the maximum wavelength of the ultraviolet absorption peaks, It is believed that this result will be helpful for the further synthesis of such antioxidants.

关键词： Polyhydroxystilbene Antioxidant activity 1,1-Diphenyl-2-picrylhydrazyl (DPPH)

Design of novel RGO/2D strip-like ZIF-8/DMAOP ternary hybrid structure towards high-efficiency microwave absorption, active and passive anti-corrosion, and synergistic antibacterial performance

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Nano Research 2024年第3期17卷 913-926页

作者： Tanlin chen Yingrui Tian Zihao Guo Yao chen qing qi Fanbin Meng Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Shenzhen Institute of Southwest Jiaotong University Shenzhen 518000China

In order to meet the requirements of the marine environment for microwave absorption(MA)materials,we put forward the strategy of constructing multi-functional composite materials,which integrate microwave absorption,anti-corrosion,and antibacterial ***,graphene oxide(GO)was used as a template to induce the growth of zeolitic imidazolate framework-8(ZIF-8),simultaneously as a two-dimensional(2D)nanocontainers to load corrosion inhibitors to achieve pH-responsive and self-healing ***,quaternary ammonium salt(dimethyl octadecyl(3-trimethoxylsilyl propyl)ammonium chloride(DMAOP))and sodium ascorbate(VCNa)were introduced to achieve synergistic antibacterial activity and the reduction of *** 2D strip-like structure of ZIF-8 was due to the confined growth induced by the electrostatic attraction between ZIF-8 and GO *** as-obtained reduced GO(RGO)/ZIF-8/DMAOP5 exhibited excellent microwave absorption(MA)properties,with a minimum reflection loss(RL)value of-47.08 dB at 12.73 GHz when the thickness was 2.8 ***,the effective absorption bandwidth reached 6.84 *** soaking in 3.5%NaCl solution for 35 days,the RGO/ZIF-8/DMAOP5-0.7%coating still achieved an impedance value of 4.585×107Ω·cm^(2) and a protective efficiency of 99.994%,providing superior anti-corrosion *** addition,fantastic antibacterial activity was obtained,with the antibacterial rates of RGO/ZIF-8/DMAOP_(10) reaching 99.39%and 100%against Escherichia coli and Staphylococcus *** work could open new avenues towards the development of a new generation of multifunctional MA materials.

关键词： two-dimensional(2D)strip-like zeolitic imidazolate framework-8(ZIF-8) microwave absorption active and passive anti-corrosion antibacterial

Effect of ceramic work rolls on surface roughness of rolled SUS304 ultra-thin strips

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Journal of Iron and Steel Research International 2024年第7期31卷 1704-1718页

作者： Peng-cheng Li Tao Wang chen-chen Zhao qi Liu qing-xue Huang College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment of Ministry of Education Taiyuan University of TechnologyTaiyuan 030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina

Surface morphology and roughness are important parameters of surface quality of cold-rolled ultra-thin strip *** order to study the effect of Si_(3)N_(4) ceramic work rolls on the surface roughness of SUS304 ultra-thin strip,ABAQUS finite element model calculation,3D laser profilometry,and other methods were adopted based on the physical characteristics of Si_(3)N_(4) ceramic roll and 9Cr2MoV steel roll,like anti-flattening performance and oil *** surface morphology and roughness of SUS304 ultra-thin strip rolled by different material work rolls under oil lubrication conditions were *** results showed that under the rolling force of 10 kN,the maximum flattening amount of Si_(3)N_(4) ceramic roll was reduced by 35.14%compared to that of 9Cr2MoV steel *** reduction rate of SUS304 ultra-thin strip rolled by ceramic roll was 34.19%,while that rolled by steel roll was only 22%;Si_(3)N_(4) ceramic roll can further increase the number of alternating convex peaks and concave valleys in the rolled thin strip,reduce the profile steepness,reduce surface roughness,and enhance the planarization effect of surface micro-convex bodies,with improving surface quality and surface ***,the mechanism of Si_(3)N_(4) ceramic roll significantly improving the surface roughness of rolled SUS304 ultra-thin strip was proposed.

关键词： Ceramic work roll-Steel roll SUS304 ultra-thin strip Reduction Surface roughness

Privacy Protection for Blockchain-Based Healthcare IoT Systems: A Survey

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1757-1776页

作者： Minfeng qi Ziyuan Wang qing-Long Han Jun Zhang Shiping chen Yang Xiang School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyHawthorn3122VictoriaAustralia Faculty of Data Science City University of MacaoMacaoChina CSIRO Data61 SydneyNew South WalesAustralia

To enable precision medicine and remote patient monitoring,internet of healthcare things(IoHT)has gained significant interest as a promising *** the widespread use of IoHT,nonetheless,privacy infringements such as IoHT data leakage have raised serious public *** the other side,blockchain and distributed ledger technologies have demonstrated great potential for enhancing trustworthiness and privacy protection for IoHT *** this survey,a holistic review of existing blockchain-based IoHT systems is conducted to indicate the feasibility of combining blockchain and IoHT in privacy *** addition,various types of privacy challenges in IoHT are identified by examining general data protection regulation(GDPR).More importantly,an associated study of cutting-edge privacy-preserving techniques for the identified IoHT privacy challenges is ***,several challenges in four promising research areas for blockchain-based IoHT systems are pointed out,with the intent of motivating researchers working in these fields to develop possible solutions.

关键词： Blockchain internet of healthcare things(IoHT) privacy-preserving techniques(PPTs).

Enhancement of comprehensive properties of Nb-Si based in-situ composites by Ho rare earth doping

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Rare Metals 2024年第9期43卷 4508-4520页

作者： Wei Wei qi Wang Rui-Run chen Chao-Wen Zheng Yan-qing Su National Key Laboratory for Precision Hot Processing of Metals School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China

This study examines the microstructure,mechanical properties(with a focus on room-temperature toughness),and oxidation resistance of Ho-doped NbDSi based in-situ *** base alloy consists of the coarse primary Nb_(5)Si_(3)phase and the Nb_(5)Si_(3)+Nbss(Nb solid solution)eutectic *** doping influences the solidification *** the Ho doping is higher than0.2 at%,the alloys transform into eutectic *** can be solid-solved in trace amounts in the Nbss ***,most of Ho forms a stable Ho oxide phase,which alleviates oxygen contamination problem to some ***,the interface separation between Ho oxide and other phases reduces the plastic deformation ***,with 0.4 at%Ho doping,the K_(Q)value is18.03 MPa·m^(1/2),which is 31.1%higher than that of the base *** strength of the Ho-doped alloys does not deteriorate with an increase in ***,the large network-like Ho_(2)O_(3)in the 0.8Ho alloy causes a decrease in toughness and *** addition,the Ho oxide phase effectively blocks the inward oxygen *** 0.8 at%Ho doping,the oxidation mass gain per unit area is 10.16 mg·cm^(2),which is 39.7%lower than that of the base alloy.

关键词： Nb-Si based composites Rare earth elements Ho Microstructure Properties

Joint training with local soft attention and dual cross-neighbor label smoothing for unsupervised person re-identification

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Computational Visual Media 2024年第3期10卷 543-558页

作者： qing Han Longfei Li Weidong Min qi Wang qingpeng Zeng Shimiao Cui Jiongjin chen School of Mathematics and Computer Sciences Nanchang UniversityNanchang 330031China Institute of Metaverse Nanchang UniversityNanchang 330031China Jiangxi Key Laboratory of Smart City Nanchang 330031China

Existing unsupervised person re-identification approaches fail to fully capture thefine-grained features of local regions,which can result in people with similar appearances and different identities being assigned the same label after *** identity-independent information contained in different local regions leads to different levels of local *** address these challenges,joint training with local soft attention and dual cross-neighbor label smoothing(DCLS)is proposed in this ***,the joint training is divided into global and local parts,whereby a soft attention mechanism is proposed for the local branch to accurately capture the subtle differences in local regions,which improves the ability of the re-identification model in identifying a person’s local significant ***,DCLS is designed to progressively mitigate label noise in different local *** DCLS uses global and local similarity metrics to semantically align the global and local regions of the person and further determines the proximity association between local regions through the cross information of neighboring regions,thereby achieving label smoothing of the global and local regions throughout the training *** extensive experiments,the proposed method outperformed existing methods under unsupervised settings on several standard person re-identification datasets.

关键词： person re-identification(Re-ID) unsupervised learning(USL) local soft attention joint training dual cross-neighbor label smoothing(DCLS)

Advanced organic electrode materials for aqueous rechargeable batteries

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Science China Chemistry 2024年第1期67卷 137-164页

作者： Gaojing Yang Yaxun Zhu qi Zhao Zhimeng Hao Yong Lu qing Zhao Jun chen Frontiers Science Center for New Organic Matter Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)College of ChemistryNankai UniversityTianjin 300071China

Organic electrode materials take advantages of potentially sustainable production and structural tunability compared with present commercial inorganic electrode ***,their applications in traditional rechargeable batteries with nonaqueous electrolytes suffer from the premature failure and safety *** comparison,aqueous rechargeable batteries based on organic electrode materials have received extensive attentions in recent years for low-cost and sustainable energy storage systems due to their inherent *** review aims to provide a comprehensive summary on the recent progress in advanced organic electrode materials for aqueous rechargeable *** start from the overview of working principles and general design strategies of organic electrode materials in aqueous rechargeable *** the research advances of organic electrode materials in various aqueous rechargeable batteries are highlighted in terms of charge carriers(monovalent ions,multivalent ions,and anions).We emphasized the characteristics of organic electrode materials in various charge ***,the critical challenges and future efforts of aqueous organic rechargeable batteries are *** organic electrode materials with better electronic conductivity and fast reaction kinetics are still needed to build advanced aqueous batteries for commercial applications.

关键词： organic electrode materials aqueous batteries organic batteries rechargeable batteries

Relaxor antiferroelectric-relaxor ferroelectric crossover in NaNbO_(3)-based lead-free ceramics for high-efficiency large-capacitive energy storage

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Chinese Chemical Letters 2024年第7期35卷 465-469页

作者： Shuangliang Xie Yuyue chen qing He Liang chen Jikun Yang Shiqing Deng Yimei Zhu He qi School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering Department of Physical ChemistryUniversity of Science and Technology BeijingBeijing 100083China School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China Department of Condensed Matter Physics and Materials Science Brookhaven National LaboratoryUptonNew York 11973United States

Relaxor ferroic dielectrics have garnered increasing attention in the past decade as promising materials for energy *** them,relaxor antiferroelectrics(AFEs)and relaxor ferroelectrics(FEs)have shown great promise in term of high energy storage density and efficiency,*** this study,a unique phase transition from relaxor AFE to relaxor FE was achieved for the first time by introducing strong-ferroelectricity BaTiO_(3)into NaNbO_(3)-BiFeO_(3)system,leading to an evolution from AFE R hierarchical nanodomains to FE polar nanoregions.A novel medium state,consisting of relaxor AFE and relaxor FE,was identified in the crossover of 0.88NaNbO_(3)–0.07BiFeO_(3)–0.05BaTiO_(3)ceramic,exhibiting a distinctive core-shell grain structure due to the composition *** harnessing the advantages of high energy storage density from relaxor AFE and large efficiency from relaxor FE,the ceramic showcased excellent overall energy storage *** achieved a substantial recoverable energy storage density W_(rec)~13.1 J/cm^(3)and an ultrahigh efficiencyη~88.9%.These remarkable values shattered the trade-off relationship typically observed in most dielectric capacitors between W_(rec)andη.The findings of this study provide valuable insights for the design of ceramic capacitors with enhanced performance,specifically targeting the development of next generation pulse power devices.

关键词： Relaxor ferroelectric Antiferroelectric Core-shell Energy storage High efficiency

Effect of alumina occurrence form on metallurgical properties of hematite and magnetite pellets

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Journal of Iron and Steel Research International 2024年第4期31卷 797-809页

作者： Jian Pan chen-mei Tang Cong-cong Yang De-qing Zhu Zheng-qi Guo Wei-qun Huang School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083HunanChina Exploration and Development of Geology and Mineral Resources Co. Ltd.Nanchang 330030JiangxiChina

The effect of alumina occurrence form on the metallurgical properties of both hematite and magnetite pellets was investigated at the same Al_(2)O level of 2 wt.%,including reduction index(RI),low-temperature reduction disintegration index(RDI),reduction swelling index(RSI),and high-temperature softening-dripping *** mineralogy of fired pellets was also studied to reveal the influence of alumina occurrence form on the phase composition and *** the results,the alumina occurrence form presents tremendous impacts on the metallurgical perfor-mance of both magnetite and hematite *** of all alumina occurrence forms contributes to inferior reducibility of pellets,especially in the case of gibbsite for magnetite pellets with a RI of 58.4%and kaolinite for hematite pellets with a RI of 56.8%.However,addition of all alumina occurrence forms improves the RDI of magnetite pellets,while there is no significant difference among various alumina occurrence *** contrast,alumina occurrence forms have little influence on the RDI of hematite *** presence of free alumina,gibbsite,and kaolinite tends to improve the RSI of hematite and magnetite pellets,whereas hercynite gives the opposite trend with a RSI of 25.6%.For softening-dripping performance of magnetite pellets,all alumina occurrence forms contribute to narrower softening-melting ***,alumina,gibbsite,and kaolinite give narrower softening-dripping interval,at 229,217,and 88℃,respectively,whereas addition of hercynite results in the largest melting range at 276℃ due to its high melting *** hematite pellets,free alumina,gibbsite,and hercynite tend to enlarge melting range,whereas kaolinite contributes to lower dripping temperature of 1148℃ and narrow softening-dripping interval of 88℃ due to the formation of a greater amount of slag phase at high temperatures.

关键词： Oxidized pellet Magnetite Hematite Alumina occurrence form Metallurgical performance Blast furnace