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Synergistic silver-mediated and palladium-catalyzed nondirected olefination of aryl C–H bond: quick access to multi-substituted aryl olefins

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Science China Chemistry 2024年第3期67卷 882-889页

作者： Jian Yao Lili Shao Xiaohong huo Xiaoming w.ng Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 20032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

Transition metal-catalyzed olefination of aryl C-H bond is a pow.rful tool for the synthesis of alkenes. w.ile the Pd-catalyzed oxidative C-H olefination of arenes, also know. as Fujiw.ra-Moritani reaction, has been established as one of the most efficient methods, the substrates are largely limited to terminal olefins w.th electron-w.thdraw.ng group(s). Herein, w. report a synergistic silver-mediated and palladium-catalyzed non-directed C-H olefination of arenes w.th vinyl(pseudo)halides, w.ich offers a complementary strategy to the typical Fujiw.ra-Moritani reaction. The reactions proceeded w.ll for a variety of halogenated arenes, heteroarenes, and olefin substrates, providing an efficient access to various multi-substituted aryl olefins, including trisubstituted/tetrasubstituted olefins and several complex olefins derived from medicines or natural products. Mechanistic studies indicated a bimetallic Pd/Ag cooperation is operative in the catalysis, i.e., the reaction is initiated by aryl C-H bond cleavage via ligation w.th phosphine/Ag species, follow.d by transferring of the aryl moiety to a vinyl palladium intermediate,w.ich is in turn formed by oxidative addition of vinyl(pseudo)halide to a Pd complex. This method enables the synthesis of a w.de range of challenging multi-substituted vinyl products from simple arenes(directing-group free) in a streamlined and controllable fashion.

关键词： direct C–H olefination multi-substituted aryl alkenes bimetallic Pd/Ag cooperation C–H functionalization

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Intensifying electrified flow.through w.ter treatment technologies via local environment modification

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Frontiers of Environmental Science & Engineering 2024年第6期18卷 17-25页

作者： Zheng-Yang huo Xiaoxiong w.ng Xia Huang Menachem Elimelech School of Environment and Natural Resources Institute of Ecological CivilizationRenmin University of ChinaBeijing 100872China Institute for Ocean Engineering Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Center of Double Helix Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Department of Chemical and Environmental Engineering Yale UniversityNew HavenCT 06520-8286USA

Removing high-risk and persistent contaminants from w.ter is challenging,because they typically exist at low.concentrations in complex w.ter *** flow.through technologies are viable to overcome the limitations induced by mass transport for efficient contaminant *** the local environment of the flow.through electrodes offers opportunities to further improve the reaction kinetics and selectivity for achieving near-complete removal of these contaminants from ***,w. present state-of-the-art local environment modification approaches that can be incorporated into electrified flow.through technologies to intensify w.ter *** first show.methods of nanospace incorporation,local geometry adjustment,and microporous structure optimization that can induce spatial confinement,enhanced local electric field,and microperiodic vortex,respectively,for local environment *** then discuss w.y local environment modification can complement the flow.through electrodes for improving the reaction rate and ***,w. outline appropriate scenarios of intensifying electrified flow.through technologies through local environment modification for fit-for-purpose w.ter treatment applications.

关键词： Point-of-use w.ter treatment Electrified membrane Advection-enhanced mass transport w.ter decontamination and disinfection Emerging contaminants

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Diversity and ecological assembly process of aerobic anoxygenic phototrophic bacteria in a low.irradiation area,Three Gorges Reservoir

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Journal of Environmental Sciences 2024年第9期143卷 116-125页

作者： Lixin huo Anran Ma Hong Liu Xingzu w.ng Cheng Song Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400714China Chongqing School University of Chinese Academy of SciencesCollege of Resources and EnvironmentChongqing 400714China Key Laboratory of Reservoir Aquatic Environment Chinese Academy of SciencesChongqing 400714China University of Chinese Academy of Sciences Beijing 100049China

Aerobic anoxygenic phototrophic bacteria(AAPB)are significant bacterial groups in aquatic ecosystems,know. for their rapid grow.h and photoheterotrophic ***,the distribution and ecological assembly process of AAPB in low.irradiation freshw.ter basins remain unclear,w.rranting further *** this study,w. present the diversity,abundance,spatial variations,ecological process,and community interaction of AAPB in sediment of Three Gorges Reservoir(TGR)under low.*** findings demonstrate the dominant genera of AAPB community that exist in the TGR area also are appeared in different w.ters,w.th some regional ***,the concentration of pufM gene,an indicator for AAPB,maintains a consistently high numerical level ranging from(2.21±0.44)×10^(4)to(9.98±0.30)×10^(7)gene copies/*** solar irradiation is suggested as the major factor affecting AAPB,it remains unclear w.ether and how.AAPB differ betw.en regions due to varying solar irradiation *** results show.spatial differences betw.en total bacteria and AAPB communities,w.th significant differences observed only in *** and environmental factor contributed less than 10%to the spatial difference of community,w.th sediment type and environmental factors being the key factors influencing microbial community *** stochastic process plays a dominant role in the aggregation and replacement of AAPB communities,among w.ich the most contribution is dispersal *** AAPB netw.rk,Yoonia and Gemmobacter are the hubs for *** results valuable insights into the AAPB communities in TGR w.th low.irradiation.

关键词： Three Gorges Reservoir(TGR) Aerobic anoxygenic phototrophic bacteria(AAPB) Bacterial community Null model Community assembly

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Colloid-facilitated release of polybrominated diphenyl ethers at an e-w.ste recycling site: evidence from undisturbed soil core leaching experiments

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 91-101页

作者： Zebin huo Mengjun Xi Lianrui Xu Chuanjia Jiang w.i Chen College of Environmental Science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China

Polybrominated diphenyl ethers (PBDEs), a class of persistent organic pollutants, have been frequently detected in soil at e-w.ste recycling sites. How.ver, the key factors controlling the transport of PBDEs from surface soil to the vadose zone and groundw.ter are unclear. Here, colloid-enhanced leaching of PBDEs from undisturbed soil cores collected at an e-w.ste recycling site in Tianjin, China, is reported. Spatially heterogeneous release of colloids and PBDEs w.s observed in all the tested soil cores under chemical and hydrodynamic perturbations, indicating the presence of preferential flow.paths. Colloid concentration in the effluent significantly increased as ionic strength decreased (from 10 to 0.01 mmol/L), probably due to the stronger electrostatic repulsion betw.en colloidal particles and the soil matrix at low.r ionic strength. In contrast, colloid mobilization w.s not significantly affected by the changes in pH of the influent (from 4.0 to 10.0) and flow.rate (from a Darcy velocity of 1.5 to 6.0 cm/h). The concentrations of 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE-209), the predominant PBDE congener at the site, detected in the leachate (ranging from 1.09 to 3.43 ng/L) w.re much low.r than previously reported results from packed column leaching tests, and w.re positively correlated w.th colloid concentrations. This indicates that remobilization of colloids at e-w.ste recycling sites can promote the leaching and dow.w.rd migration of PBDEs from surface soil. The findings highlight the potential risk of surface soil PBDE contamination to groundw.ter quality and call for further understanding of colloid-facilitated transport for predicting the fate of PBDEs at e-w.ste recycling sites.

关键词： Polybrominated diphenyl ether Colloid-facilitated transport E-w.ste recycling site Undisturbed soil core Groundw.ter quality

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Facile synthesis of composite polyferric magnesium-silicate-sulfate coagulant w.th enhanced performance in w.ter and w.stew.ter

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 574-584页

作者： Xiangtao huo Rongxia Chai Lizheng Gou Mei Zhang Min Guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The coagulation process is a w.dely applied technology in w.ter and w.stew.ter *** composite polyferric mag-nesium-silicate-sulfate(PFMS)coagulants w.re synthesized using Na_(2)SiO_(3)·9H_(2)O,Fe_(2)(SO_(4))_(3),and MgSO_(4) as raw.materials in this *** effects of aging time,Fe:Si:Mg,and OH:M molar ratios(M represents the metal ions)on the coagulation performance of the as-pre-pared PFMS w.re systematically investigated to obtain optimum *** results show.d that PFMS coagulant exhibited good co-agulation properties in the treatment of simulated humic acid-kaolin surface w.ter and reactive dye *** the molar ratio w.s controlled at Fe:Si:Mg=2:2:1 and OH:M=0.32,the obtained PFMS presented excellent stability and a high coagulation *** removal efficiency of ultraviolet UV254 w.s 99.81%,and the residual turbidity of the surface w.ter reached 0.56 NTU at a dosage of 30 mg·L^(-1).After standing the coagulant for 120 d in the laboratory,the removal efficiency of UV254 and residual turbidity of the surface w.-ter w.re 88.12%and 0.68 NTU,respectively,w.ich accord w.th the surface w.ter treatment *** addition,the coagulation performance in the treatment of reactive dye w.stew.ter w.s greatly improved by combining the advantages of magnesium and iron *** w.th polyferric silicate-sulfate(PFS)and polymagnesium silicate-sulfate(PMS),the PFMS coagulant played a better decolor-ization role w.thin the pH range of 7-13.

关键词： polyferric-magnesium-silicate-sulfate composite coagulants w.ter and w.stew.ter excellent stability high coagulation ef-ficiency decolorization

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Integral precession calibration method of PIGA on linear vibration table

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Chinese Journal of Aeronautics 2024年第3期37卷 219-236页

作者： Chuang SUN Shun-qing REN Jun-w.i CAO Ru huo Department of Automation Tsinghua UniversityBeijing 100084China School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China Faculty of Information technology Beijing University of TechnologyBeijing 100124China

Linear vibration table can provide harmonic accelerations to excite the nonlinear error terms of Pendulous Integrating Gyro Accelerometer(PIGA).Integral precession calibration method is proposed to calibrate PIGA on a linear vibration table in this *** on the precise expressions of PIGA’s inputs,the error calibration model of PIGA is *** angular velocity errors of PIGA are suppressed by integer periodic precession and the errors caused by non-integer periods vibrating are *** complete calibration process,including planning,preparation,PIGA testing,and coefficient identification,is designed to optimize the test operations and evaluate the calibration *** effect of the main errors on calibration uncertainty is analyzed and the relative sensitivity function is proposed to further optimize the test *** and simulation results verify that the proposed 10-position calibration method can improve calibration uncertainties after compensating for the related *** order of calibration uncertainties of the second-and third-order coefficients are decreased to 10^(-8)(rad.s^(-1))/g^(2)and 10^(-8)(rad.s^(-1))/g3,*** w.th the other tw. classical calibration methods,the calibration uncertainties of PIGA’s nonlinear error coefficients can be effectively reduced and the proportional residual errors are decreased less than 3×10-6(rad.s^(-1))/g by using the proposed calibration method.

关键词： PIGA Linear vibration table Vibration measurement Calibration Error analysis Uncertainty analysis

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Considering individual game behavior and time delay in the multi-channel rumor propagation model

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Communications in Theoretical Physics 2024年第7期76卷 9-29页

作者： Yafang Dong Liang'an huo Xiaoxiao Xie Ming Li Business School University of Shanghai for Science and TechnologyShanghai 200093China School of Intelligent Emergency Management University of Shanghai for Science and TechnologyShanghai 200093China

The rapid development of the Internet has accelerated the spread of rumors,posing challenges to social cohesion and *** address this,a multi-channel rumor propagation model incorporating individual game behavior and time delay is *** depicts individuals strategically choosing propagation channels in the rumor spread process,capturing real-w.rld intricacies more ***,the model allow.ng spreaders to choose betw.en text and video information base *** adoption hinges on benefits versus costs,w.th payoffs dictating strategy and the propagation process determining an individual's *** theoretical analysis of the model,the propagation threshold and equilibrium points are *** the stability of the model is further demonstrated based on Routh-Hurw.tz judgment and Descartes'Rule of *** simulations are conducted to verify the correctness of the theoretical results and the sensitivity of the model to key *** outcomes reveal that increasing the propagation cost of spreaders can significantly curb the spread of *** contrast to the classical ISR model,rumors spread faster and more w.dely in the improved multi-channel rumor propagation model in this paper,w.ich is a feature more aligned w.th real-w.rld ***,the validity and predictive ability of the model are verified by using real rumor propagation data sets,indicating that the improved multi-channel rumor propagation model has good practical application and predictive value.

关键词： multi-channel rumor propagation time delay game behavior

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Generalized nth-Order Perturbation Method Based on Loop Subdivision Surface Boundary Element Method for Three-Dimensional Broadband Structural Acoustic Uncertainty Analysis

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 2053-2077页

作者： Ruijin huo Qingxiang Pei Xiaohui Yuan Yanming Xu College of Architecture and Civil Engineering Xinyang Normal UniversityXinyang464000China Henan Unsaturated Soil and Special Soil Engineering Technology Research Center Xinyang Normal UniversityXinyang464000China Henan International Joint Laboratory of Structural Mechanics and Computational Simulation College of Architecture and Civil EngineeringHuanghuai UniversityZhumadian463000China

In this paper,a generalized nth-order perturbation method based on the isogeometric boundary element method is proposed for the uncertainty analysis of broadband structural acoustic scattering *** Burton-Miller method is employed to solve the problem of non-unique solutions that may be encountered in the external acoustic field,and the nth-order discretization formulation of the boundary integral equation is *** addition,the computation of loop subdivision surfaces and the subdivision rules are *** order to confirm the effectiveness of the algorithm,the computed results are contrasted and analyzed w.th the results under Monte Carlo simulations(MCs)through several numerical examples.

关键词： Perturbation method loop subdivision surface isogeometric boundary element method uncertainty analysis

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Synergistic asymmetric diarylation of tethered alkenes via C–H functionalization of simple(hetero)arenes

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Science China Chemistry 2024年第8期67卷 2710-2718页

作者： Jian Yao Can Zhao Lili Shao Xiaohong huo Xiaoming w.ng Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in Chemical Synthesis Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

By virtue of the atom-and step-economy, utilization of simple arenes as a supplant of pre-prepared aryl metal species or aryl halides for the synthesis of arylated chiral molecules has attracted great attention from the synthetic community. w.ile transition-metal-catalyzed enantioselective diarylation of tethered alkenes has been employed to prepare important chiral cyclic compounds, the direct use of simple arenes as aryl precursors is still underdeveloped, probably due to the difficulties in the effective control of the reactivity, site-selectivity and/or enantioselectivity. Herein w. report an asymmetric Pd/Ag dual metal catalytic system for the non-directed, site-and enantioselective domino Heck/intermolecular C–H functionalization of *** studies show.d that Pd and Ag act in cooperation in the catalysis and the chiral bisphosphine ligand plays a bifunctional role, i.e., assisting the silver species in the cleavage of the aryl C–H bond, w.ile inducing the enantioselectivity on direct complexation w.th palladium. This method provides an efficient approach to the corresponding chiral oxindoles w.th good enantiomeric excesses from a broad scope of arenes, including fluoroarenes, heteroarenes and several complex products derived from medicines or natural products.

关键词： asymmetric Pd/Ag dual metal catalytic system simple arenes C–H functionalization bifunctional role chiral oxindoles

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Shear band evolution and acoustic emission characteristics of sandstone containing non-persistent flaw.

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 497-513页

作者： Shuting Miao Peng-Zhi Pan Chuanqing Zhang Lei huo State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China CASIC Research Institute of Intelligent Decision Engineering Wuhan430040China

Direct shear tests w.re conducted on sandstone specimens under different constant normal stresses to study the coalescence of cracks betw.en non-persistent flaw. and the shear sliding characteristics of the shear-formed *** image correlation and acoustic emission(AE)techniques w.re used to monitor the evolution of shear bands at the rock bridge area and microcracking *** experimental results revealed that the shear stresses corresponding to the peak and sub-peak in the stressdisplacement curve are significantly affected by the normal *** localization bands emerged at both the tip of joints and the rock bridge,and their extension and interaction near the peak stress caused a surge in the AE hit rate and a significant decrease in the AE b *** and curvilinear strain bands w.re detected at low.normal stress,w.ile high normal stress generally led to more microcracking events and longer coplanar cracks at the rock bridge ***,an increase in normal stress resulted in a higher AE count rate and more energetic AE events during friction sliding along the shearformed *** w.s observed that the elastic energy released during the crack coalescence at the prepeak stage w.s much greater than that released during friction sliding at the post-peak *** than 75%of AE events w.re located in the low.frequency band(0e100 kHz),and this proportion continued to rise w.th increasing normal ***,more AE events of low.AF value and high RA value w.re observed in specimens subjected to high normal stress,indicating that greater normal stress led to more microcracks of shear nature.

关键词： Shear band evolution Acoustic emission(AE) Crack coalescence Normal stress Shear sliding

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