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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 311-318页

作者： Lin Shibin Jeramy c.Ashlock zhu Liming Qin Zexiang Li Bo zhu xingji Zhai changhai State Key Laboratory of Precision Blasting Jianghan UniversityWuhan 430056China Hubei Key Laboratory of Blasting Engineering Jianghan UniversityWuhan 430056China Department of civil Construction&Environmental EngineeringIowa State UniversityAmesIA 50010USA Wuhan Airport Road Development co. Ltd.Wuhan 430065China School of civil and Environmental Engineering Harbin Institute of TechnologyShenzhen 518055China Key Lab of Structures Dynamic Behavior and control of the Ministry of Education Harbin Institute of TechnologyHarbin 150090China Key Lab of Smart Prevention and Mitigation of civil Engineering Disaster of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin 150090China

A trigger system is typically employed in active seismic testing to trigger and synchronize multichannel surface wave data *** effect of the trigger system on the dispersion image of surface waves is empirically known to be negligible,however,theoretical explanation regarding the effect of the trigger system is *** study systematically examines the theory for surface wave dispersion analysis and proves that the effect of the trigger system on a dispersion image is negligible via a solid theoretical ***,based on the new theoretical explanation,an alternative method that uses only the relative phase difference between sensors to extract dispersion characteristics with better conceptual clarity is *** active surface wave testing cases are considered to validate the theory and *** results indicate that(1)an accurate trigger system is not necessary for surface wave data acquisition,and(2)it is unnecessary to assume that the impact point is the generation point of the surface waves for the experimental dispersion analysis.

关键词： site investigation surface waves data acquisition dispersion

carbon coated LaFe_(0.92)Pd_(0.08)O_(3) composites for catalytic transfer hydrogenation:Balance in the ability of substrates adsorption and conversion

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Nano Research 2024年第5期17卷 3724-3732页

作者： Bowen Wang Nan Zhang Ping xiao Jian Zhang Sónia A.c.carabineiro Junjiang zhu Hubei Key Laboratory of Biomass Fibers and Eco-dyeing&Finishing College of Chemistry and Chemical EngineeringWuhan Textile UniversityWuhan 430200China college of chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035China LAQV-REQUIMTE Department of ChemistryNOVA School of Science and TechnologyUniversidade NOVA de LisboaLargo da Torre2829-516 CaparicaPortugal

catalytic transfer hydrogenation(cTH)is a green and efficient pathway for selective hydrogenation of unsaturated aldehydes and ***,managing the abilities of solid catalysts to adsorb substrates and to convert them into desired products is a challenging ***,we report the synthesis of carbon coated LaFe_(0.92)Pd_(0.08)O_(3) composites(LFPO-8@c)for cTH of benzaldehyde(BzH)into benzyl alcohol(BzOH),using isopropanol(IPA)as hydrogen *** coating with carbon improves the ability to adsorb/transfer reactants from solution to active sites,and the doping of Pd2+at Fe3+site strengthens the ability of LaFeO_(3) to convert BzH into BzOH.A balanced point between them(i.e.,abilities to adsorb BzH and to convert BzH into BzOH)is obtained at LFPO-8@c,which exhibits a BzOH formation rate of 3.88 mmol·gcat^(-1)·h^(-1) at 180℃ for 3 h,which is 1.50 and 2.72 times faster than those of LFPO-8 and LaFeO_(3)@c.A reaction mechanism is proposed,in which the acidic sites(e.g.,Fe^(4+),oxygen vacancy)are used for the activation of c=O bond of BzH and O-H bond of IPA,and the basic sites(e.g.,lattice oxygen)for the activation ofα-H(O-H)bond of IPA.

关键词： LaFe_(0.92)Pd_(0.08)O_(3) porous carbon catalytic transfer hydrogenation isopropanol reaction mechanism

Benzoyl cyanide, a general radical acylating reagent for photoredox-catalyzed benzylic site-selective acylation reactions

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Science china chemistry 2024年第11期67卷 3833-3843页

作者： Zhaodong zhu Jingjing Wu Frontiers Science center for Transformative Molecules Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs School of Chemistry and Chemical Engineering Zhangjiang Institute for Advanced Study Shanghai Jiao Tong University

Based on rational design, benzoyl cyanide, a well-known ionic acylating reagent, has been developed as a general radical acylating reagent for benzylic site-selective acylation reactions for the first time. Using visible-light photoredox-catalyzed single electron transfer(SET) and hydrogen atom transfer(HAT) strategies, two different direct benzylic c–H acylation reactions with high atom economy have been developed. This newly developed radical acylating reagent could also be used to achieve three component acyltrifluoromethylation of styrenes, which is usually challenging to achieve by other means. All of these reactions proceed under mild nickel-free and NHc-free conditions with high functional group tolerance. In addition, based on our detailed mechanistic experiments, the process of radical-radical cross-coupling mechanism was suggested for these transformations.

关键词： photoredox catalysis benzylic c–H acylation radical acylating reagent HAT catalysis acyltrifluoromethylation

Modulating the degree of O vacancy defects to achieve selective control of electrochemical cO_(2) reduction products

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chinese chemical Letters 2024年第5期35卷 482-486页

作者： Tianbo Jia Lili Wang Zhouhao zhu Baikang zhu Yingtang Zhou Guoxing zhu Mingshan zhu Hengcong Tao School of Petrochemical Engineering&Environment Zhejiang Ocean UniversityZhoushan 316022China Department of General Practice First Medical CenterChinese PLA General HospitalBeijing 100853China National&Local Joint Engineering Research center of Harbor Oil&Gas Storage and Transportation Technology Zhoushan 316022China School of chemistry and chemical Engineering Jiangsu UniversityZhenjiang 212013China Guangdong Key Laboratory of Environmental Pollution and Health School of EnvironmentJinan UniversityGuangzhou 511443China

conversion of cO_(2) into high-value products using electrochemical cO_(2) reduction(EcR)technology is an effective way to alleviate global warming and reach carbon *** oxygen vacancies in heterogenous catalysis are generally considered as a powerful method to enhance the performance of EcR by promoting cO_(2) adsorption and ***,the extent of defects in oxygen vacancies-activity relation has rarely been ***,we prepared cu-cd bimetallic catalysts with adjustable oxygen defect degree by controlling the amount of cadmium *** transform infrared spectroscopy characterization results reveal that the formation of oxygen vacancies is attributed to the asymmetric stretching of cu-O by the addition of *** results show that the oxygen defect degree can modulate the selectivity of EcR products.A low degree of oxygen defects(cuO)is generally associated with lower product Faraday efficiency(FE_(c2)/FE_(c1)≈114%),but overabundant oxygen vacancies(cuO_(2.625)-cdO_(0.375))are not entirely favorable to improving EcR activity(FE_(c2)/FE_(c1)≈125%)and single selectivity,while an appropriate degree of oxygen vacancies(cuO_(2.75)-cdO_(0.25))can facilitate the EcR process toward single product selective production(FE_(c2)/FE_(c1)≈296%).The theoretical calculation showed that the O vacancy formed on cuO and the interface between cdO and cuO were conducive to enhancing the formation of ^(*)cOOH intermediate and promoting the generation of ethylene *** study provides a new approach and insight into the selective production of single products for future industrial applications of EcR.

关键词： cO_(2) O-vacancies Bimetallic catalysts copper oxide cadmium oxide Selective

controllable chemical redox reactions to couple microbial degradation for organic contaminated sites remediation:A review

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Journal of Environmental Sciences 2024年第5期139卷 428-445页

作者： Bin chen Jiang xu Lizhong zhu college of Environmental and Resource Sciences Zhejiang UniversityHangzhou 310058China Zhejiang Provincial Key Laboratory of Organic Pollution Process and control Zhejiang UniversityHangzhou 310058China Zhejiang Agriculture&Forest University Lin'an 311300China

Global environmental concern over organic contaminated sites has been progressively conspicuous during the process of urbanization and industrial *** traditional physical or chemical remediation technologies may significantly destroy the soil structure and function,coupling moderate chemical degradation with microbial remediation becomes a potential way for the green,economic,and efficient remediation of contaminated ***,this work systematically elucidates why and how to couple chemical technology with microbial remediation,mainly focused on the controllable redox reactions of organic *** rational design of materials structure,selective generation of reactive oxygen species,and estimation of degradation pathway are described for chemical ***,current progress on efficient and selective reductions of organic contaminants(i.e.,dechlorination,defluorination,-NO_(2) reduction)is *** with the microbial remediation of contaminated sites,several consideration factors of how to couple chemical and microbial remediation are proposed based on both fundamental and practical points of *** review will advance the understanding and development of chemical-microbial coupled remediation for organic contaminated sites.

关键词： Soil remediation Groundwater remediation Rational design Reactive species Environmental nanotechnology

c@Ag core‒shell structure as lubricating additives towards high efficient lubrication

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Friction 2024年第9期12卷 1991-2003页

作者： Dong AO xiaoqiang FAN Minhao zhu Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Tribology Research Institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Efficient cooperative lubrication can be achieved via the introduction of core‒shell structure lubricant additives with hard core and soft shell,for obtaining the expected anti-wear performance from the structural changes in the friction *** this study,c@Ag microspheres with a core‒shell structure were prepared by the redox method with carbon spheres as the core and Ag nanoparticles as the *** tribological behaviors as base oil(G1830)additive with different concentrations were investigated in *** with base oil,the addition of c@Ag particles at 0.5 wt%can reduce the coefficient of friction(cOF)and wear volume(Wv)up to 15.5%and 88%,*** importantly,c@Ag particles provide superior lubrication performance to single additive(like carbon sphere(cS)and Ag nanoparticle).c@Ag core‒shell particles contribute to the formation of tribo-film by melt bonding of flexible Ag and carbon sphere(cS)toward excellent self-repair performance and high-efficiency ***,core‒shell structural nanoparticles with hard-core and soft-shell hold bright future for high-performance lubrication application.

关键词： c@Ag microspheres tribo-film self-repair performance high-efficiency lubrication

Maximal operators of pseudo-differential operators with rough symbols

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Applied Mathematics(A Journal of chinese Universities) 2024年第1期39卷 174-180页

作者： Ramla Benhamoud zhu xiang-rong School of Mathematical Sciences Zhejiang Normal UniversityJinhua 321004China

consider a pseudo-differential operator T_(a)f(x)=∫_(R^(n))e^(ix,ζ)a(x,ζ)f(ζ)dζwhere the symbol a is in the rough Hormander class L^(∞)S_(ρ)^(m)with m∈R andρ∈[0,1].In this note,when 1≤p≤2,if n(ρ-1)/p and a∈L^(∞)S_(ρ)^(m),then for any f∈S(R^(n))and x∈R^(n),we prove that M(T_(a)f)(x)≤c(M(|f|^(p))(x))^(1/p) where M is the Hardy-Littlewood maximal *** theorem improves the known results and the bound on m is sharp,in the sense that n(ρ-1)/p can not be replaced by a larger constant.

关键词： pseudo-differential operator rough Hormander class H-L maximal operator

Topological Stability and Entropy for certain Set-valued Maps

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Acta Mathematica Sinica,English Series 2024年第4期40卷 962-984页

作者： Yu ZHANG Yu Jun zhu School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China

In this paper,the dynamics(including shadowing property,expansiveness,topological stability and entropy)of several types of upper semi-continuous set-valued maps are mainly considered from differentiable dynamical systems points of *** is shown that(1)if f is a hyperbolic endomorphism then for eachε>0 there exists a c^(1)-neighborhood U of f such that the induced set-valued map F_(f,U)has theε-shadowing property,and moreover,if f is an expanding endomorphism then there exists a c^(1)-neighborhood U of f such that the induced set-valued map F_(f,U)has the Lipschitz shadowing property;(2)when a set-valued map F is generated by finite expanding endomorphisms,it has the shadowing property,and moreover,if the collection of the generators has no coincidence point then F is expansive and hence is topologically stable;(3)if f is an expanding endomorphism then for eachε>0 there exists a c^(1)-neighborhood U of f such that h(F_(f,U,ε))=h(f);(4)when F is generated by finite expanding endomorphisms with no coincidence point,the entropy formula of F is ***,the dynamics of the set-valued maps based on discontinuous maps on the interval are also considered.

关键词： Set-valued map orbit space hyperbolic endomorphism perturbation shadowing expansiveness topological stability entropy

Effect of confining pressure on rock breaking by high-pressure waterjet-assisted TBM

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Underground Space 2024年第5期18卷 151-161页

作者： chen xu Yujie zhu xiaoli Liu Fei chen Min zhu Enzhi Wang Sijing Wang School of Resource and Environment Engineering Wuhan University of TechnologyWuhan 430070China changjiang Institute of Survey PlanningDesign and ResearchWuhan 430010China State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources Wuhan 430010China

High-pressure waterjet-assisted tunnel boring machine(WTBM)is an efficient method for improving the tunneling performance of a tunnel boring machine(TBM)and reducing the wear of its disc cutters in hard rock with high *** pressure directly affects the efficiency of rock breaking and the configuration of the disc *** this study,we evaluated the effect of confining pressure on WTBM rock breaking by developing a self-designed and manufactured experimental system,including confining pressure loading,TBM disc-cutter penetration,and high-pressure *** macro fracture,acoustic emission(AE),peak normal force drop,and specific energy(SE)were analyzed for four different confining pressures(10,20,30,and 35 MPa).The results showed that the cutting depth of the waterjet increased linearly as the waterjet pressure increased and decreased with the gradual increase in the nozzle moving *** expansion and development of cracks formed rock debris,and the size of the rock fragments decreased with an increase in confining *** the waterjet pressure was 280 MPa,the nozzle moving velocity was 800 mm/min and the kerf space was 75 mm,which indicated that the confining pressure,which was 23.16 MPa,minimized the cutting SE under this ***,regardless of the confining pressure,the maximum normal force of WTBM was less than that of a TBM,whereas the SE of WTBM was less than that of complete TBM cutting mode(cTcM).The average force drop and average drop rate of SE were approximately 25%,and 80%,*** results of this study can inspire the design and mechanism of a TBM assisted by a high-pressure waterjet.

关键词： Waterjet Tunnel boring machine(TBM) confining pressure Specific energy Force drop