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Preheating-assisted solid-state friction stir repair of Al-Mg-Si alloy plate at different rotational speeds

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 725-736页

作者： Hui Wang Yidi li ming Zhang Wei Gong Ruilin Lai Yunping li State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Research Institute of light Alloy Central South UniversityChangsha 410083China

Additive friction stir deposition(AFSD)is a novel structural repair and manufacturing technology has become a research hotspot at home and abroad in the past five *** this work,the microstructural evolution and mechanical performance of the Al-Mg-Si alloy plate repaired by the preheating-assisted AFSD process were *** evaluate the tool rotation speed and substrate preheating for repair quality,the AFSD technique was used to additively repair 5 mm depth blind holes on 6061 aluminum alloy *** results showed that preheat-assisted AFSD repair significantly improved joint bonding and joint strength compared to the control non-preheat substrate ***,increasing rotation speed was also beneficial to improve the metallurgical bonding of the interface and avoid volume *** preheating conditions,the UTS and elongation were positively correlated with rotation *** the process parameters of preheated substrate and tool rotation speed of 1000 r/min,defect-free specimens could be obtained accompanied by tensile fracture occurring in the substrate rather than the repaired *** UTS and elongation reached the maximum values of 164.2MPa and 13.4%,which are equivalent to 99.4%and 140%of the heated substrate,respectively.

关键词： additive friction stir deposition structural repair tool rotation speed Al alloy

TBAB hydrate formation and growth in a microdevice under static and dynamic conditions

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Petroleum Science 2024年第2期21卷 1396-1404页

作者： Xingxun li ming liu Qingping li Weixin Pang Guangjin Chen Changyu Sun State Key Laboratory of Heavy Oil Processing China University of Petroleum BeijingBeijing102249China State Key Laboratory of Natural Gas Hydrate CNOOC Research Institute Co.Ltd.Beijing100027China

The natural gas hydrate has become one of the most promising future green energy sources on the *** natural gas hydrates mostly exist in the sediments with porous structure, so a solid understanding of the hydrate formation and growth processes in the porous medium is of significance for the exploitation of natural gas hydrate. The micro-packed bed device is one of the efficient microfluidic devices in the engineering field, but it has been rarely used for the hydrate-based research. In this study, a transparent micro-packed bed device filled with glass beads was developed to mimic the porous condition of sediments, and used to in-situ visualize the hydrate formation and growth habits in the pore spaces under both static and dynamic conditions. For the static experiment, two types of hydrate growth patterns in porous medium were observed and identified in the micro-packed bed device, which were the graincoating growth and pore-filling growth. For the dynamic condition, the hydrate formation, growth,distribution habits and hydrate blockage phenomena in the pore spaces were in-situ visually *** impacts of flowrate and subcooling on the pressure variation of the micro-packed bed and the duration of the hydrate growth under dynamic flow condition in pores were in-situ monitored and analyzed. The higher flowrate could result in the faster hydrate growth and more severe blockage in pores, but the effect of subcooling condition might be less significant at the high flowrate.

关键词： Hydrate formation Hydrate growth Microdevice In-situ measurement

Local environment regulation of transition metal dichalcogenide-based single-atom catalysts

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Rare Metals 2024年第9期43卷 4019-4037页

作者： ming-Hui li Jing li Xiao-Yu Zheng Yao Zhou Advanced Research Institute of Multidisciplinary Science and School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100081China Laser Micro/Nano Fabrication Laboratory School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China

Single-atom catalysts have risen significant attention in the realm of green electrocatalytic energy conversion to address energy and environmental sustainability *** metal dichalcogenide(TMD)-based single-atom catalysts are considered highly effective in electrocatalysis due to the TMDs'notable specific surface area,tunable elemental species and efficient utilization of single *** order to enhance electrocatalytic performance,it is imperative to elaborately engineer the local environment surrounding the active sites of single atoms within *** this review,we initially explore the effects of synthesis methods on single-atom active sites and the influence of loading of single atoms on catalytic performance for *** modulation strategies of the local environment surrounding single-atom sites in TMDs are elaborated,including substitution engineering,surface adsorption,vacancies,spatial confinement and dual-atom site *** each modulation strategy,the effects of diverse local environments on various electrocatalytic applications are presented,such as the oxygen evolution reaction,oxygen reduction reaction,nitrogen reduction reaction,CO_(2)reduction reaction and CO ***,this study presents a comprehensive overview of the challenges encountered and the potential directions for the advancement of single-atom catalysts based on TMDs in the realm of electrocatalysis.

关键词： Single-atom catalysts Transition metal dichalcogenide Local environment Electrocatalysis

Molecular solid solution of lanthanide-titanium-oxo clusters with enhanced photocatalytic hydrogen evolution

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Science China Chemistry 2024年第2期67卷 529-535页

作者： Rong Chen Chao-Long Chen Hui Zhang zi-Han Wang Fu-li Sun ming-Hao Du Gui-lin Zhuang Cheng Wang La-Sheng Long Lan-Sun Zheng Xiang-Jian Kong Collaborative Innovation Centre of Chemistry for Energy Materials State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry College of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China College of Chemical Engineering Zhejiang University of TechnologyHangzhou310032China

Molecular solid solutions of metal clusters containing different metal centers with well-defined structures can accurately regulate the HOMO-LUMO gap,but are rarely ***,a series of colorless lanthanide-titanium-oxo clusters Ln_(2)Ti_4(μ_(2)-O)_(2)(μ_(3)-O)_4(Piv)_(10)(THF)_(2)(Ln_(2)Ti_4,Ln = Eu,Gd,Tb,and Ce,HPiv = pivalic acid) were synthesized by the reaction of pivalic acid with Ln(Ac)_(3) and titanium *** light yellow crystal of cluster solid solutions Eu_(2)Ti_(4-x)Cd_(x),containing a mixture of Eu_(2)Ti_4 and Eu_(2)Ti_(3)Cd,was obtained by in situ doping Cd^(2+) and S^(2–).Eu_(2)Ti_(3.92)Cd_(0.08) displays efficient photocatalytic hydrogen evolution activity without a co-catalyst,which is up to 2.6 times that of Eu_(2)Ti_*** time-resolved transient absorption spectroscopy and spin-polarized density functional calculations showed that the enhanced photocatalytic performance of Eu_(2)Ti_(4-x)Cd_(x) can be attributed to the narrower HOMO-LUMO gap and lower LUMO position than that of Eu_(2)Ti_*** studyprovides an in situ doping method to realize the simple preparation of cluster solid solution.

关键词： molecular solid solution lanthanide-titanium-oxo clusters photocatalytic hydrogen evolution

Spherical Polyelectrolyte Brush Nanoreactor:Preparation of Hollow TiO_(2) Nanospheres and Characterization by Small Angle X-Ray Scattering

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Chinese Journal of Polymer Science 2024年第9期42卷 1393-1400,I0009页

作者： Yu-Hua Zhang zi-Yu Zhang Xin liu En-Guang Ma Jiang-Tao Guo li li Xu-Hong Guo State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai200237China Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology College of Chemistry and Chemical EngineeringDezhou UniversityDezhou253023China Institute of Bast Fiber Crops&Center of Southern Economic Crops Chinese Academy of Agricultural SciencesChangsha410205China

Titanium dioxide(TiO_(2))hollow nanoparticles present significant potential for photocatalytic applications while their straightforward preparation with precise structure control is still *** work reports the approach to preparing tunable hollow TiO_(2) nanospheres by utilization of spherical polyelectrolyte brushes(SPB)as nanoreactors and *** the preparation,the evolution of the structure was characterized by small angle X-ray scattering(SAXS),and in combination with dynamic light scattering and transmission electron *** formation of TiO_(2) shell within the brush(SPB@TiO_(2))is confirmed by the significant increase of the electron density,and its internal structure has been analyzed by fitting SAXS data,which can be influenced by Titanium precursors and ammonia *** calcining SPB@TiO_(2) in a muffle furnace,hollow TiO_(2) nanospheres are produced,and their transition to the anatase crystal form is triggered,as confirmed by X-ray diffraction *** the advantages of their hollow structure,these TiO_(2) nanospheres exhibit exceptional catalytic degradation efficiency of methylene blue(MB),tetracycline(TC),and 2,4-dichlorophenoxyacetic acid(2,4-D),and also demonstrate excellent recyclability.

关键词： Spherical polyelectrolyte brush Nanoreactor Hollow titanium dioxide X-ray scattering

Hybrid treatment of varied orthodontic appliances for a patient with skeletal class II and temporomandibular joint disorders:A case report and review of literature

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World Journal of Clinical Cases 2024年第2期12卷 431-442页

作者： Tong Lu li Mei Bao-Chao li zi-Wei Huang Huang li Department of Orthodontics Nanjing Stomatological HospitalThe Affiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008Jiangsu ProvinceChina Discipline of Orthodontics Department of Oral ScienceFaculty of DentistryUniversity of OtagoDunedin 9016New Zealand

BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a *** TMD symptoms occur during orthodontic treatment,an immediate pause of orthodontic adjustments is recommended;the treatment can resume when the symptoms are managed and *** SUMMARY This case report presents a patient(26-year-old,female)with angle class I,skeletal class II and *** treatment was a hybrid of clear aligners,fixed appliances and temporary anchorage devices(TADs).After 3 mo resting and treatment on her TMD,the patient’s TMD symptom alleviated,but her anterior occlusion displayed deep ***,the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep *** the levelling,the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her *** careful examination of temporomandibular joints(TMJ)position,the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her ***,the improved facial appearance and relatively stable occlusion were *** 1-year follow-up records showed there was no obvious change in TMJ morphology,and her occlusion was *** TMD screening and monitoring is of great clinical importance in the TMD susceptible *** treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.

关键词： Temporomandibular disorder Skeletal class II Deep overbite Dual bite Invisible mandibular advancement appliance Case report

Beyond 1,4-addition of in-situ generated(aza-)quinone methides and indole imine methides

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Chinese Chemical Letters 2024年第7期35卷 35-53页

作者： Yan-li li Zhi-ming li Kai-Kai Wang Xiao-Long He Medical College Xinxiang UniversityXinxiang 453000China School of Pharmacy Xinxiang UniversityXinxiang 453000China School of Food and Bioengineering Xihua UniversityChengdu 610039China

The conjugate addition of in-situ generated(aza-)quinone methides(QMs)and indole imine methides(IIMs)emerged as a powerful protocol to access densely functionalized benzenes and *** alcohols,aminobenzhydryl alcohols,and varied indolylmethanols served as most effective precursors for the in-situ generation of such reactive species under acid *** relevant propargylic alcohol has proven to be an elegant precursor to generate the propargylic-QMs and-IIMs via the acid promoted dehydration process,thus enabling diverse challenging remote activation to proceed conjugate1,6-and 1,***,the heteroarene has proven to be workable to transfer the LUMO of the p-QMs and 2-IIMs,thus inducing the remote nucleophilic dearomative *** conjugate additions of(aza-)p-QMs and varied IIMs has made significant contribution in the field of remote activation chemistry in past *** review summarizes the latest advances of the remote conjugate additions of the in-situ generated QMs and IIMs.

关键词： Conjugate addition QMs IIMs LUMO Remote activation Dearomative addition

Thoracic spinal cord injury and paraplegia caused by intradural cement leakage after percutaneous kyphoplasty: A case report

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World Journal of Clinical Cases 2024年第10期12卷 1837-1843页

作者： zi Mao Zhi-Hong Xiong Jun-Feng li Department of Pain Management The Affiliated Hospital of Yunnan UniversityKunming 650000Yunnan ProvinceChina Department of Medical Administration The Affiliated Hospital of Yunnan UniversityKunming 650000Yunnan ProvinceChina

BACKGROUND Percutaneous kyphoplasty(PKP)is a pivotal intervention for osteoporotic fractures,pathological vertebral compression fractures,and vertebral bone *** its efficacy,the procedure presents challenges,notably complications arising from intradural cement *** and accurate diagnosis,coupled with emergent intervention is imperative to improve patient *** case report illuminates the intricacies and potential complications associated with PKP,emphasizing the critical need for vigilant monitoring,prompt diagnosis,and immediate intervention to mitigate adverse *** SUMMARY A 58-year-old male patient,experiencing a T7 osteoporosis-related pathological compression fracture,underwent PKP at a local *** weeks postprocedure,the patient developed paraplegic and dysuric symptoms,necessitating emergency decompression *** improvement was achieved,marked by the restoration of muscle strength,sensation,and *** PKP Intradural cement leakage following PKP is unusual and potentially *** imaging examinations,urgent evaluation,and the decompression surgery are essential,which help alleviate symptoms associated with spinal damage,markedly improving the overall prognosis.

关键词： Percutaneous kyphoplasty Intradural cement leakage Complication Decompression surgery Case report

Exploring the Pathogenesis of Autoimmune liver Diseases from the Heterogeneity of Target Cells

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Journal of Clinical and Translational Hepatology 2024年第7期12卷 659-666页

作者： zi-Xuan Qiu lin-Xiang Huang Xiao-Xiao Wang zi-Long Wang Xiao-He li Bo Feng Peking University People’s Hospital Peking University Hepatology InstituteBeijing Key Laboratory of Hepatitis C and Immunotherapy for Liver DiseasesBeijing International Cooperation Base for Science and Technology on NAFLD DiagnosisBeijingChina

The incidence of autoimmune liver diseases(ALDs)and research on their pathogenesis are increasing ***,except for autoimmune hepatitis,which responds well to immunosuppression,primary biliary cholangitis and primary sclerosing cholangitis are insensitive to immunosuppressive *** the known effects of the environment,genetics,and immunity on ALDs,the heterogeneity of target cells provides new insights into their *** review started by exploring the heterogeneity in the development,structures,and functions of hepatocytes and epithelial cells of the small and large bile *** example,cytokeratin(CK)8 and CK18 are primarily expressed in hepatocytes,while CK7 and CK19 are primarily expressed in intrahepatic ***,emerging technologies of single-cell RNA sequencing and spatial transcriptomic are being applied to study *** review offered a new perspective on understanding the pathogenic mechanisms and potential treatment strategies for ALDs.

关键词： Autoimmune hepatitis Primary biliary cholangitis Primary sclerosing cholangitis Disease heterogeneity Single-cell RNA sequencing Pathogenesis