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Chinese Chemical Letters 2015年第10期26卷 1319-1321页

作者： jiu-cun chen Jun-Zhi Li Jian-Hua Liu Li-Qun Xu Institute for Clean Energy & Advanced Materials Southwest University State Key Laboratory of Medicinal Chemical Biology Nankai University Chongqing Key Laboratory for Advanced Materials & Technologies of Clean Energies

A set of amphiphilic poly（ethylene glycol）-b-poly（ethylene brassylate）（PEG-b-PEB） copolymers based on the PEB hydrophobic block was first synthesized by ring-opening polymerization of ethylene brassylate with an organic catalyst. The EB/PEG molar ratios and reaction times were adjusted to achieve different chain lengths of PEB. Block copolymers that were characterized by1 H NMR and GPC could selfassemble into multimorphological aggregates in aqueous solution, which were characterized by DLS and TEM. The hydrophobic doxorubicin（DOX） was chosen as a drug model and successfully encapsulated into the nanoparticles. The release kinetics of DOX were investigated.

关键词： Poly(ethylene brassylate) Self-assembly Nanoparticles Controlled drug release

Analytical Solution for the Reissner-Sagoci Problem of a Piezoelectric Half-Space

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Acta Mechanica Solida Sinica 2024年第3期37卷 363-370页

作者： Keqiang Hu cun-Fa Gao Zengtao chen Zheng Zhong State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China Department of Mechanical Engineering University of AlbertaEdmontonABT6G 1H9Canada School of Science Harbin Institute of TechnologyShenzhen518055China

In this paper,a transversely isotropic piezoelectric half-space with the isotropy axis parallel to the z-axis is considered under rotation on a rigid circular disk bonded to the surface of the piezoelectric *** is a type of Reissner-Sagoci mixed boundary value *** utilizing the Hankel transform,the mixed boundary value problem is simplified into solving a pair of dual integral ***-field analytical expressions for displacement,stresses,and electric displacement inside the half-space are *** shear stresses and electric displacement on the surface are found to be singular at the edge of the rigid circular disk,and the stress intensity factors and electric displacement intensity factor are *** results show that material properties and geometric size have significant effects on displacement,shear stresses,and electric displacement.

关键词： Piezoelectric half-space Circular disk Reissner-Sagoci problem Stress intensity factor Electric displacement intensity factor

Atomistic study of inverse size effect induced by interfacial plasticity in pearlitic multi-principal element alloy

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Rare Metals 2024年第7期43卷 3341-3355页

作者： chen Yang Qiao-Sheng Xia cun-Hong Yin Dong-Peng Hua College of Mechanical Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Advanced Manufacturing Technology Ministry of EducationGuizhou UniversityGuiyang 550025China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China

Owing to the fine nano-laminated structure,the pearlitic multi-principal element alloy(PMPEA) exhibits excellent mechanical and tribological ***,the incomplete understanding of the size effect of its lamella thickness and the unclear understanding of the plasticity-interface interaction mechanism limit further optimization of *** this study,the FeCoNi/Ni_3Ti interface-mediated plastic deformation behavior in PMPEA and the variation of mechanical and tribological properties with lamella thickness within the nanoscale range using molecular dynamics(MD) simulation were *** results indicate that the mechanical and tribological properties of the PMPEA with lamella thicknesses below 10 nm have a significant inverse size effect,i.e.,the smaller the lamella thickness,the weaker the *** is because the plastic carrier-interface interaction mechanism changes from a strengthening mechanism that hinders dislocations to a weakening mechanism that promotes dislocations with the decreases in the lamella thickness,and the weakening effect becomes more pronounced as the lamella thickness decreases and the number of interfaces *** particular,the deformation behavior of Ni_3Ti lamellae changes from crystal-like to amorphous-like with decreasing ***,in the sample with larger lamella thickness,the occurrence of hierarchical slips in the body-centered cubic(BCC) phase due to the multiprincipal elements effect can better alleviate the stress concentration caused by the dislocation accumulation at the interface,so that the phase interface exhibits outstanding load-bearing *** the dislocation pattern in BCC phase shows a firm high-density cell,which makes the substrate exhibit a stable tribological response.

关键词： Multi-principal element alloy Nano-laminated structure Molecular dynamics simulation Nanoindentation and nanoscratch

Elastic three-dimensional phononic topological insulators with Dirac hierarchy

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 54-62页

作者： Shao-Yong Huo Qiu-Shuang Yang jiu-jiu chen Hong-Kang Li Long-Chao Yao Fu-Chun He Chun-Ming Fu College of Mechanical Engineering University of South ChinaHengyang 421001China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

Three-dimensional(3D)phononic topological insulators(TIs)featuring two-dimensional(2D)surface states and one-dimensional(1D)hinge states have opened up a new route for multi-dimensional robust wave transport,providing unprecedented methods for integrated acoustic sensors and energy harvesting ***,aiming at the elastic 3D phononic TI with gapless surface states and hinge states,the realization of elastic 3D phononic TIs with gapless surface states and hinge states is a significant challenge due to the complicated multi-mode polarization of elastic waves in 3D *** this study,we demonstrate an elastic 3D phononic TI with a Dirac hierarchy by elaborately operating the corresponding spatial symmetries of the chiral honeycomb ***,a 3D double Dirac cone of elastic wave can be achieved by doubling the lattice along the outof-plane direction to fold two iso-frequency Weyl *** topological phase transitions and 2D gapless two-fold Dirac surface states of elastic wave are realized by breaking the half-lattice spatial translation ***,based on the Brillouin zone folding along the in-plane direction,the 2D gapless two-fold surface Dirac cones are folded into four-fold surface Dirac ***,by inducing the relative radius of adjacent holes to break the in-plane spatial inversion symmetry,the fourfold surface Dirac cones are gapped and associated with a surface state inversion,in which the gapless 1D hinge Dirac dispersion is *** research offers a route for engineering the hierarchies of TIs in 3D elastic wave systems and provides new possibilities for designing 3D ultrasonic devices with unconventional functions.

关键词： Dirac topological hierarchy

Realizing the excellent oxidation resistance of an environmental barrier coating through aluminum surface modification

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Journal of Advanced Ceramics 2024年第7期13卷 976-986页

作者： Lin Dong Wen-Qi Yang Lin chen Guan-Jun Yang Chang-jiu Li State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an Aerospace Engine Company Limited in China Aerospace Science and Technology Corporation Xi’an 710065China

The lifetime of Si-based environmental barrier coatings(EBCs)is constrained by thermally grown SiO_(2)oxidelayer(SiO_(2)-TGO),which can cause premature cracking and *** address this issue,a new approach for surfacemodification using aluminum is *** oxidation performance was examined in a 50 vol%H_(2)O-50 vol%O_(2)environment at 1350℃for up to 300 *** results indicate that a dense ytterbium aluminum garnet(YbAG)layer wasformed after modification,decreasing the porosity by 80%.Due to the elimination of fast diffusion channels and the lowoxygen permeability of YbAG,aluminum modification significantly reduced the growth rate of SiO_(2)-TGO by nearly twoorders of ***,its thickness decreased by more than 70%after 300 h of exposure.A diffusioncontrolled oxidation mechanism indicates that the modified dense surface is equivalent to an initial SiO_(2)layer with a specificthickness,causing a shift in the oxidation time and increasing the oxidation *** research provides valuableinsights for designing Si-based EBC with improved lifetimes.

关键词： environmental barrier coating(EBC) oxidation modification diffusion cracking

Durable dual-state duplex Si-HfO_(2)with excellent oxidation and cracking resistance

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Journal of Advanced Ceramics 2024年第3期13卷 388-401页

作者： Lin chen Jing-Chuan Luo Wen-Qi Yang Chang-jiu Li Guan-Jun Yang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an Aerospace Engine Company Limited in CASC Xi’an 710065China

The lifetime of Si bond coatings in environmental barrier coatings is constrained by phase-transition-induced cracking of the SiO_(2)*** this study,Si-HfO_(2)dual-state duplex composite materials are proposed to address this issue by partially forming HfSiO_(4)and minimizing the SiO_(2)*** as-prepared composite exhibited a structure comprising discrete HfO_(2)“bricks”embedded in a continuous Si“mortar”,while the oxidized state transformed into discrete HfSiO_(4)“bricks”within continuous thin SiO_(2)“mortars”.The results indicate that continuous thin SiO_(2)contributes to reducing the oxidation rate to a level comparable to that of pure Si,and discrete HfSiO_(4)particles aid in relieving phase transition-induced stress and inhibiting crack propagation,thereby enhancing oxidation and cracking resistance ***,the composite with 20 mol%HfO_(2)and a mean particle size of~500 nm at 1370℃exhibited a service lifetime 10 times greater than that of pure *** research provides valuable insights for designing Si-based bond coatings with improved service lifetime.

关键词： oxidation environmental barrier coatings(EBCs) phase transition cracking bond coatings

d-d Orbital coupling induced by crystal-phase engineering assists acetonitrile electroreduction to ethylamine

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Journal of Energy Chemistry 2024年第2期89卷 216-225,I0006页

作者： Honggang Huang Yao chen Hui Fu cun chen Hanjun Li Zhe Zhang Feili Lai Shuxing Bai Nan Zhang Tianxi Liu Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122JiangsuChina Department of Chemistry KU LeuvenCelestijnenlaan 200FLeuven 3001Belgium College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071ShandongChina

The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in electrochemical acetonitrile reduction reaction(ARR)to ***,we successfully realize the structural transformation of Pd Cu metallic aerogels(MAs)from face-centered cubic(FCC)to body-centered cubic(BCC)through annealing ***,the BCC Pd Cu MAs exhibit excellent ARR performance with high ethylamine selectivity of 90.91%,Faradaic efficiency of 88.60%,yield rate of 316.0 mmol h^(-1)g^(-1)_(Pd+Cu)and long-term stability for consecutive electrolysis within 20 h at-0.55 V *** hydrogen electrode,outperforming than those of FCC Pd Cu *** the membrane electrode assembly system,BCC Pd Cu MAs also demonstrate excellent ethylamine yield rate of 389.5 mmol h^(-1)g^(-1)_(Pd+Cu).Density functional theory calculation reveals that the d-d orbital coupling in BCC Pd Cu MAs results in an evident correlation effect for the interaction of Pd and Cu sites,which boosts up the Cu sites electronic activities to enhance ARR *** work opens a new route to develop efficient ARR electrocatalysts from the perspective of crystalline structure transformation.

关键词： d-d Orbital coupling Crystal-phase engineering Metallic aerogels Acetonitrile electroreduction reaction Ethylamine

Compaction and seepage characteristics of broken coal and rock masses in coal mining:A review in laboratory tests

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第2期3卷 1-20页

作者： cun Zhang Yanhong chen Zhaopeng Ren Fangtian Wang School of Energy and Mining Engineering China University of Mining and Technology(Beijing)Beijing 100083China Engineering Research Center of Green and Intelligent Mining for Thick Coal Seam Ministry of EducationBeijing 100083China School of Mines China University of Mining&TechnologyXuzhou221116China

Broken coal and rock(BCR)are an important component medium of the caving zone in the goaf(or gob),as well as the main filling material of fault fracture zone and collapse *** compaction seepage characteristics of BCR directly affect the safe and efficient mining of coal ***,numerous laboratory studies have focused on the compaction seepage characteristics of *** paper first outlines the engineering problems involved in the BCR during coal mining including the air leakage,the spontaneous combustion,the gas drainage,and the un-derground reservoirs in the *** inrush related to tectonics such as faults and collapse columns and surface subsidence related to coal gangue filling and mining also involve the compaction seepage characteristics of *** on the field problems of BCR,many attempts have been made to mimic field environments in laboratory *** experimental equipment(cavity size and shape,acoustic emission,CT,etc.)and experimental design for the BCR were firstly *** main objects of laboratory analysis can be divided into compression tests and seepage *** the compaction test,the main research focuses on the bearing deformation characteristics(stress-strain curve),pore evolution characteristics,and re-crushing characteristics of *** seepage test mainly uses gas or water as the main medium to study the evolution characteristics of permeability under different compaction stress *** the laboratory tests,factors such as the type of coal and rock mass,particle size,particle shape,water pressure,temperature,and stress path are usually *** lateral compression test of BCR can be divided into three stages,including the self-adjustment stage,the broken stage,and the elastic stage or stable *** each stage,stress,deformation,porosity,energy,particle size and breakage rate all have their own *** test regarding the water permeability experiment of BCR is actually belong to variabl

关键词： Coal mining Broken coal and rock Laboratory test Engineering problems Experimental equipment Breakage characteristics Compaction characteristics Seepage characteristics

Targeting ASIC1a Promotes Neural Progenitor Cell Migration and Neurogenesis in Ischemic Stroke

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Research 2024年第1期2023卷 369-387页

作者： Hongfei Ge Tengyuan Zhou Chao Zhang Yupeng cun Weixiang chen Yang Yang Qian Zhang Huanhuan Li Jun Zhong Xuyang Zhang Hua Feng Rong Hu Department of Neurosurgery and Key Laboratory of Neurotrauma Southwest HospitalThird Military Medical University(Army Medical University)400038 ChongqingChina Medical Research Center Southwest HospitalThird Military Medical University(Army Medical University)400038 ChongqingChina Pediatric Research Institute Ministry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChildren’s Hospital of Chongqing Medical University400014 ChongqingChina

Cell replacement therapy using neural progenitor cells(NPCs)has been shown to be an effective treatment for ischemic ***,the therapeutic effect is unsatisfactory due to the imbalanced homeostasis of the local microenvironment after *** acidosis is a common imbalanced homeostasis in the penumbra and could activate acid-sensing ion channels 1a(ASIC1a),a subunit of proton-gated cation channels following ischemic ***,the role of ASIC1a in NPCs post-ischemia remains ***,our results indicated that ASIC1a was expressed in NPCs with channel functionality,which could be activated by extracellular *** evidence revealed that ASIC1a activation inhibited NPC migration and neurogenesis through RhoA signaling-mediated reorganization of filopodia formation,which could be primarily reversed by pharmacological or genetic disruption of *** vivo data showed that the knockout of the ASIC1a gene facilitated NPC migration and neurogenesis in the penumbra to improve behavioral recovery after stroke.

关键词： ASIC1a homeostasis inhibited

Biochar with self-doped N to activate peroxymonosulfate for bisphenol-A degradation via electron transfer mechanism:The active edge graphitic N site

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Chinese Chemical Letters 2024年第9期35卷 351-355页

作者： Yun-Xin Huang Lin-Qian Yu Ke-Yu chen Hao Wang Shou-Yan Zhao Bao-cheng Huang Ren-cun Jin School of Engineering Hangzhou Normal UniversityHangzhou 311121China Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change Hangzhou 311121China

Environmental endocrine disruptors,represented by bisphenol A(BPA),have been widely detected in the environment,bringing potential health risks to human ***-containing biocarbon catalyst can activate peroxymonosulfate(PMS)to degrade BPA in water,but its active sites remain ***,in this work,nitrogen-containing biochar,i.e.,C–Nedge,enriched with graphitic-N defects at the edges was prepared by one-pot co-pyrolysis of chitosan and potassium *** results showed that the C–Nedge/PMS system can effectively degrade 98%of BPA(50 mg/L).The electron transfer based non-radical oxidation mechanism was responsible for BPA *** graphitic-N doping endows biochar with strong electron transfer *** catalyst had good recovery and reuse *** catalytic oxidation was also feasible for other refractory pollutants removal and worked well for treating practical *** work may provide valuable information in unraveling the N doping configurationactivity relationship during activating PMS by biochar.

关键词： Peroxymonosulfate Carbon-based catalysts Edge graphitic-N Non-radicals Bisphenol A