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Ring-opening Copolymerization of ε-Caprolactone and δ-Valerolactone Catalyzed by a 2,6-Bis(amino)phenol Zinc Complex

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Chinese Journal of Polymer Science 2020年第3期38卷 240-247,I0006页

作者： Qian Hu Su-Yun Jie Pierre Braunstein bo-geng li State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China Universitéde Strasbourg CNRSCHIMIE UMR 7177Laboratoire de Chimie de Coordination67081 Strasbourg CedexFrance

In combination with methyllithium,a 2,6-bis(amino)phenol zinc complex 1 was used in the ring-opening polymerization ofδ-valerolactone in the absence or presence of benzyl alcohol and showed high efficiency,mainly producing cyclic and linear polyvalerolactones,respectively.On the basis of homopolymerization,the ring-opening copolymerization ofε-caprolactone andδ-valerolactone was investigated.The P(CL-co-VL)random copolymers,PCL-b-PVL and PVL-b-PCL diblock copolymers,were prepared by varying the feeding strategy(premixing or sequential feeding).The copolymer composition was adjusted by varying the feeding ratio of two monomers.The structure and thermal properties of obtained polymers were characterized by GPC,1 H-NMR,13 C-NMR,MALDI-TOF mass spectroscopy,and DSC,respectively.

关键词： Zn complex Copolymerization Block copolymer Random copolymer

Nickel(Ⅱ) a-Diimine Catalysts with Carboxyl Groups for Ethylene Oligomerization and Polymerization

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Chinese Journal of Polymer Science 2016年第2期34卷 221-228页

作者： Bing liu Meng-zhe Fang 介素云 Zhi-yang Bu bo-geng li State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China

A series of nickel（II） α-diimine complexes with strong electron-withdrawing carboxyl groups, having reactive hydrogen atoms, were prepared and used as precatalysts for ethylene oligomerization and/or polymerization. The influence of metal halides and ligand structure on the catalytic activity and properties of products was investigated. The results showed that nickel bromide was much more active than nickel chloride, and the substituents at the ortho-position of aryl ring had large influence on the properties of products. Therefore, the products ranging from liquid oligomers to polymers could be readily obtained by the variation of the substituents on the ligands and reaction conditions.

关键词： α-Diimine Nickel Ethylene Oligomerization Polymerization.

Fabrication of metal-organic framework-based nanofibrous separator via one-pot electrospinning strategy

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Nano Research 2021年第5期14卷 1465-1470页

作者： Congcong Chen Weidong Zhang He Zhu bo-geng li Yingying Lu Shiping Zhu State Key Lab of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou310027China Institute of Pharmaceutical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou310027China School of Science and Engineering The Chinese University of Hong KongShenzhenShenzhen518172China Department of Chemical Engineering McMaster UniversityHamiltonOntarioL8S 4L7Canada

Metal-organic framework(MOF)/polymer composites have attracted extensive attention in the recent years.However,it still remains challenging to efficiently and effectively fabricate these composite materials.In this study,we propose a facile one-pot electrospinning strategy for preparation of HKUST-1/polyacrylonitrile(PAN)nanofibrous membranes from a homogeneous stock solution containing HKUST-1 precursors and PAN.MOF crystallization and polymer solidification occur simultaneously during the electrospinning process,thus avoiding the issues of aggregation and troublesome multistep fabrication of the conventional approach.The obtained HKUST-1/PAN electrospun membranes show uniform MOF distribution throughout the nanofibers and yield good mechanical properties.The membranes are used as separators in li-metal full batteries under harsh testing conditions,using an ultrathin li-metal anode,a high mass loading cathode,and the HKUST-1/PAN nanofibrous separator.The results demonstrate significantly improved cycling performance(capacity retention of 83.1%after 200 cycles)under a low negative to positive capacity ratio(N/P ratio of 1.86).The improvement can be attributed to an enhanced wettability of the separator towards electrolyte stemmed from the nanofibrous structure,and a uniform lithium ion flux stabilized by the open metal sites of uniformly distributed HKUST-1 particles in the membrane during cycling.

关键词： one-pot electrospinning strategy metal-organic framework composite nanofibrous membrane battery separator

Rare esophageal carcinoma-primary adenoid cystic carcinoma of the esophagus: A case report

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World Journal of Clinical Cases 2024年第3期12卷 630-636页

作者： li-Dan geng Jie li li Yuan Xiao-bo Du Department of Oncology Mianyang Central HospitalMianyang 621000Sichuan ProvinceChina

BACKGROUND Esophageal adenoid cystic carcinoma(EACC)is an exceedingly rare malignant tumor of the esophagus,posing significant challenges in the clinic.CASE SUMMARY This report detailed the case of a 72-year-old male whose diagnosis of EACC was confirmed through postoperative histopathological examination.The patient underwent thoracoscopy-assisted radical resection of the esophageal tumor,coupled with lymph node dissection.Pathological findings revealed an adenoid cystic carcinoma infiltrating the entire layer of the muscularis propria,locally extending into the outer membrane of the esophageal fiber,involving the cardia and exhibiting no lymph node metastasis.The patient’s condition was classified as primary EACC,T3N0M0,per the American Joint Committee on Cancer(2017;8th edition).One month after surgery,the patient received postoperative adjuvant radiation therapy.CONCLUSION In addressing the rarity and high potential for biopsy misdiagnosis of EACC,this study delved into its diagnostic methods and treatment.

关键词： Esophageal adenoid cystic carcinoma Malignant tumor Lymph node dissection Adjuvant radiation therapy Misdiagnosis Case report

Structural engineered living materials

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Nano Research 2024年第2期17卷 715-733页

作者： Yang geng Zian Jia ling li 635 Prices Fork Road Department of Mechanical EngineeringVirginia Polytechnic Institute and State UniversityBlacksburg VA24061USA

Biological structural materials not only exhibit remarkable mechanical properties but also often embody dynamic characteristics such as environmental responsiveness,autonomy,and self-healing,which are difficult to achieve in conventional engineering materials.By merging materials science,synthetic biology,and other disciplines,engineered living materials(ELMs)provide a promising solution to combine living organisms with abiotic components,thus facilitating the construction of functional“living”materials.like natural materials,ELMs possess vitality and hold immense application potential in areas such as medicine,electronics,and construction,captivating increasing research attention recently.As an emerging branch of ELMs,structural ELMs aim to mimic living biological structural materials by achieving desired mechanical performance while maintaining important“living”characteristics.Here we summarize the recent progress and provide our perspectives for this emerging research area.We first summarize the superiority of structural ELMs by reviewing biological structural materials and biomimetic material design strategies.Subsequently,we provide a systematic discussion on the definition and classifications of structural ELMs,their mechanical performance,and physiological behaviors.Finally,we summarize some critical challenges faced by structural ELMs and highlight directions of future development.We hope this review article can provide a timely summary of the state of the art and relevant perspectives for future development of structural ELMs.

关键词： structural materials engineered living materials(ELMs) structural ELMs composites mechanical properties

Concurrent hetero-/homo-geneous electrocatalysts to bi-phasically mediate sulfur species for lithium-sulfur batteries

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Journal of Energy Chemistry 2024年第6期93卷 663-668,I0016页

作者： Rui-bo lingHu Jin-Xiu Chen Jin-Hao Zhang bo-Quan li Qing-Shan Fu Gulnur Kalimuldina geng-Zhi Sun Yunhu Han Long Kong Xi’an Institute of Flexible Electronics(IFE) Northwestern Polytechnical UniversityXi’an 710129ShaanxiChina Institute of Advanced Materials Nanjing Tech UniversityNanjing 211816JiangsuChina Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Department of Mechanical and Aerospace Engineering School of Engineering and Digital SciencesNazarbayev UniversityKabanbay Batyr Ave.53Astana 010000Kazakhstan

Expediting redox kinetics of sulfur species on conductive scaffolds with limited charge accessible surface is considered as an imperative approach to realize energy-dense and power-intensive lithium-sulfur(li-S)batteries.In this work,the concept of concurrent hetero-/homo-geneous electrocatalysts is proposed to simultaneously mediate liquid-solid conversion of lithium polysulfides(liPSs)and solid lithium disulfide/sulfide(li_(2)S_(2)/li_(2)S)propagation,the latter of which suffers from sluggish reduction kinetics due to buried conductive scaffold surface by extensive deposition of li_(2)S_(2)/li_(2)S.The selected model material to verify this concept is a two-in-one catalyst:carbon nanotube(CNT)scaffold supported iron-cobalt(Fe-Co)alloy nanoparticles and partially carbonized selenium(C-Se)component.The Fe-Co alloy serves as a heterogeneous electrocatalyst to seed li_(2)S_(2)/li_(2)S through sulphifilic active sites,while the C-Se sustainably releases soluble lithium polyselenides and functions as a homogeneous electrocatalyst to propagate li_(2)S_(2)/li_(2)S via solution pathways.Such bi-phasic mediation of the sulfur species benefits reduction kinetics of liPS conversion,especially for the massive li_(2)S_(2)/li_(2)S growth scenario by affording an additional solution directed route in case of conductive surface being largely buried.This strategy endows the li-S batteries with improved cycling stability(836 mA h g^(-1)after 180 cycles),rate capability(547 mA h g^(-1)at 4 C)and high sulfur loading superiority(2.96 mA h cm^(-2)at 2.4 mg cm^(-2)).This work hopes to enlighten the employment of bi-phasic electrocatalysts to dictate liquid-solid transformation of intermediates for conversion chemistry batteries.

关键词： lithium-sulfur batteries Electrocatalysis lithium polysulfides Sulfur cathode Energy density

Multi-physics multi-scale simulation of unique equiaxed-to-columnar-to-equiaxed transition during the whole solidification process of Al-li alloy laser welding

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Journal of Materials Science & Technology 2024年第4期171卷 235-251页

作者： Chu Han Ping Jiang Shaoning geng liangyuan Ren School of Mechanical Science and Engineering Huazhong University of Science&Technology(HUST)Wuhan430074China

In this study,a novel multi-physics multi-scale model with the dilute multicomponent phase-field method in three-dimensional(3D)space was developed to investigate the complex microstructure evolu-tion in the molten pool during laser welding of Al-li alloy.To accurately compute mass data within both two and three-dimensional computational domains,three efficient computing methods,including central processing unit parallel computing,adaptive mesh refinement,and moving-frame algorithm,were uti-lized.Emphasis was placed on the distinctive equiaxed-to-columnar-to-equiaxed transition phenomenon that occurs during the entire solidification process of Al-li alloy laser welding.Simulation results indi-cated that the growth distance of columnar grains that epitaxially grew from the base metal(BM)de-creased as the nucleation rate increased.As the nucleation rate increased,the morphology of the newly formed grains near the fusion boundary(FB)changed from columnar to equiaxed,and newly formed equiaxed grains changed from having high-order dendrites to no obvious dendrite structure.When the nucleation rate was sufficiently high,non-dendritic equiaxed grains could directly form near the FB,and there was nearly no epitaxial growth from the BM.Additionally,simulation results illustrated the com-petition among multiple grains with varying orientations that grow in 3D space near the FB.Finally,how equiaxed grain bands develop was elucidated.The equiaxed band not only hindered the growth of early columnar grains but also some of its grains could grow epitaxially to form new columnar grains.These predicted results were in good agreement with experimental measurements and observations.

关键词： Laser welding Al-li alloy Equiaxed-to-columnar-to-equiaxed transition Multi-physics multi-scale model Multicomponent alloys 3D phase-field model

boosting reversible charging of li-ion batteries at low temperatures by a synergy of propylene carbonate-based electrolyte and defective graphite

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Nano Research 2024年第3期17卷 1491-1499页

作者： Yingqiang Wu Jiao Zhang Jinli liu li Sheng bo Zhang limin Wang Siqi Shi li Wang Hong Xu Xiangming He Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences(CAS)Changchun 130022China China National Quality Supervision and Inspection Center for Industrial Explosive Materials Nanjing University of Science and TechnologyNanjing 210094China School of Materials Science and Engineering Materials Genome InstituteShanghai UniversityShanghai 200444China

Propylene carbonate(PC)-based electrolytes have exhibited significant advantages in boosting the low-temperature discharging of graphite-based li-ion batteries.However,it is still unclear whether they can improve the charging property and suppress lithium plating.Studying this topic is challenging due to the problem of electrochemical compatibility.To overcome this issue,we introduced graphite with phase defects.The results show that the pouch-type full batteries using PC-based electrolyte exhibit steady performance over 500 cycles and can be reversibly charged over 30 times at-20℃ with an average Coulombic efficiency of 99.95%,while the corresponding value for the conventional ethylene carbonate(EC)-based electrolyte sample is only 31.20%.This indicates that the use of PC-based electrolyte significantly suppresses lithium plating during low-temperature charging.We further demonstrate that the improved performance is mainly attributed to the unique solvation structure,where PF-6more anions participate in solvation,leading to the formation of a stable F-rich solid state electrolyte interface on the graphite surface and a lower reduction tendency of li+ions.This work inspires new ideas for the design of PC-based electrolytes for low-temperature charging and fast-charging batteries.

关键词： lithium-ion batteries graphite propylene carbonate low-temperature charging

Enhancing Relational Triple Extraction in Specific Domains:Semantic Enhancement and Synergy of Large Language Models and Small Pre-Trained Language Models

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Computers, Materials & Continua 2024年第5期79卷 2481-2503页

作者： Jiakai li Jianpeng Hu geng Zhang School of Electronic and Electrical Engineering Shanghai University of Engineering ScienceShanghai201620China

In the process of constructing domain-specific knowledge graphs,the task of relational triple extraction plays a critical role in transforming unstructured text into structured information.Existing relational triple extraction models facemultiple challenges when processing domain-specific data,including insufficient utilization of semantic interaction information between entities and relations,difficulties in handling challenging samples,and the scarcity of domain-specific datasets.To address these issues,our study introduces three innovative components:Relation semantic enhancement,data augmentation,and a voting strategy,all designed to significantly improve the model’s performance in tackling domain-specific relational triple extraction tasks.We first propose an innovative attention interaction module.This method significantly enhances the semantic interaction capabilities between entities and relations by integrating semantic information fromrelation labels.Second,we propose a voting strategy that effectively combines the strengths of large languagemodels(LLMs)and fine-tuned small pre-trained language models(SLMs)to reevaluate challenging samples,thereby improving the model’s adaptability in specific domains.Additionally,we explore the use of LLMs for data augmentation,aiming to generate domain-specific datasets to alleviate the scarcity of domain data.Experiments conducted on three domain-specific datasets demonstrate that our model outperforms existing comparative models in several aspects,with F1 scores exceeding the State of the Art models by 2%,1.6%,and 0.6%,respectively,validating the effectiveness and generalizability of our approach.

关键词： Relational triple extraction semantic interaction large language models data augmentation specific domains