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Intermolecular Acid-Base-Pairs Containing Poly(p-Terphenyl-co-Isatin Piperidinium) for High temperature Proton Exchange Membrane Fuel Cells

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Energy & Environmental Materials 2024年第3期7卷 410-418页

作者： Xiaofeng Hao Zhen Li Min Xiao Zhiheng Huang Dongmei Han Sheng Huang Wei Liu Shuanjin Wang Yuezhong Meng The Key Laboratory of low-carbon Chemistry & Energy Conservation of Guangdong Province State Key Laboratory of Optoelectronic Materials and TechnologiesSchool of Materials Science and EngineeringSun Yat-sen University School of Chemical Engineering and Technology Sun Yat-sen University Institute of Chemistry Henan Provincial Academy of Sciences Research center of Green Catalysts College of ChemistryZhengzhou University

How to optimize and regulate the distribution of phosphoric acid in matrix,and pursuing the improved electrochemical performance and service lifetime of high temperature proton exchange membrane （HT-PEMs） fuel cell are significant ***,bifunctional poly （p-terphenyl-co-isatin piperidinium） copolymer with tethered phosphonic acid （t-PA） and intrinsic tertiary amine base groups are firstly prepared and investigated as *** distinctive architecture of the copolymer provides a well-designed platform for rapid proton *** not only transports through the hydrogen bond network formed by the adsorbed free phosphoric acid （f-PA）anchored by the tertiary amine base groups,but also rely upon the proton channel constructed by the ionic cluster formed by the t-PA *** the design of the structure,the bifunctional copolymers with lower PA uptake level （lower PA leaching and higher voltage stability,which is a top leading result in disclosed *** results demonstrate that the design of intermolecular acid-base-pairs can improve the proton conductivity without sacrificing the intrinsic chemical stability or mechanical property of the thin membrane,realizing win-win demands between the mechanical robustness and electrochemical properties of HT-PEMs.

关键词： bifunctional copolymer high temperature proton exchange membrane intermolecular acid–base-pairs phosphonic acid retention phosphonic acid uptake level

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Molecular mechanism for the unusual enhancement of the second-step chemiluminescence production from the carcinogenic tetrabromohydroquinone and H2O_(2)

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Journal of Environmental sciences 2024年第7期141卷 330-342页

作者： Zi-Han Wang Chun-Hua Huang Zhi-Sheng Liu Li Mao Ben-Zhan Zhu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Environment and Resources University of Chinese Academy of SciencesBeijing 100049China

We have found recently that two-step intrinsic hydroxyl radical(·OH)-dependent chemiluminescence(CL)could be produced by carcinogenic tetrahaloquinone and H_(2)O_(2).However,the first-step CL was too fast to clearly detect the stepwise generation of·OH and CL,and to distinguish the exact dividing point between the first-step and second-step *** we found that,extremely clear two-step intrinsic CL could be produced by the relative slow reaction of tetrabromohydroquinone(TBHQ)with H_(2)O_(2),which was directly dependent on the two-step·OH ***,the second-step,but not the first-step CL production of TBHQ/H_(2)O_(2)(CRET donor)was markedly enhanced by fluorescein(a typical xanthene dye,CRET acceptor)through a unique chemiluminescence resonance energy transfer(CRET)*** novel CRET system of TBHQ/H_(2)O_(2)/fluorescein was successfully applied for the sensitive detection of TBHQ with the detection limit as low as 2.5μmol/*** findings will help to develop more sensitive and highly efficient CL or CRET systems and specific CL sensor to detect the carcinogenic haloquinones,which may have broad environmental applications.

关键词： Two-step chemiluminescence Bromohydroquinone Hydrogen peroxide Hydroxyl radical CRET

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Accelerated generation of holograms with ultra-low memory symmetrically high-compressed look-up table

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Chinese Physics B 2024年第4期33卷 466-471页

作者：杨燕朱建英孙敏远毕勇 Applied Laser Research center Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of sciences Beijing 100049China

Computer-generated holography technology has been widely applied,and as research in this field deepens,the demand for memory and computational power in small AR and VR devices continues to *** paper presents a hologram generation method,i.e.,a symmetrically high-compressed look-up table method,which can reduce memory usage by50%.In offline computing,half of the basic horizontal and vertical modulation factors are stored,halving the memory requirements without affecting inline ***,its potential extends to various holographic applications,including the production of optical diffraction elements.

关键词： computergenerated hologram look-up table holography

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Developmental toxicity assessment of neonicotinoids and organophosphate esters with a human embryonic stem cell-and metabolism-based fast-screening model

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Journal of Environmental sciences 2024年第3期137卷 370-381页

作者： Shuxian Zhang Miaomiao Zhao Shichang Li Renjun Yang Nuoya Yin Francesco Faiola State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

In recent years,neonicotinoids(NEOs)and organophosphate esters(OPEs)have been widely used as substitutes for traditional pesticides and brominated fame-retardants,*** studies have shown that those compounds can be frequently detected in environmental and human samples,are able to penetrate the placental barrier,and are toxic to ***,it is reasonable to speculate that NEOs and OPEs may have potential adverse effects in humans,especially during *** employed a human embryonic stem cell differentiation-and liver S9 fraction metabolism-based fast screening model to assess the potential embryonic toxicity of those two types of *** show that four NEO and five OPE prototypes targeted mostly ectoderm specification,as neural ectoderm and neural crest genes were down-regulated,and surface ectoderm and placode markers *** liver S9 fraction's treatment could generally reduce the effects of the chemicals,except in a few specific instances,indicating the liver may detoxify NEOs and *** findings suggest that NEOs and OPEs interfere with human early embryonic development.

关键词： Neonicotinoids Organophosphate esters Human embryonic stem cells Fast screening model Developmental toxicity

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NSNO:Neumann Series Neural Operator for Solving Helmholtz Equations in Inhomogeneous Medium

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Journal of Systems Science & Complexity 2024年第2期37卷 413-440页

作者： CHEN Fukai LIU Ziyang LIN Guochang CHEN Junqing SHI Zuoqiang Department of Mathematical sciences Tsinghua UniversityBeijing 100084China Yau Mathematical sciences center Tsinghua UniversityBeijing 100084China Yanqi Lake Beijing Institute of Mathematical sciences and Applications Beijing 101408China

In this paper,the authors propose Neumann series neural operator(NSNO)to learn the solution operator of Helmholtz equation from inhomogeneity coefficients and source terms to *** equation is a crucial partial differential equation(PDE)with applications in various scientific and engineering ***,efficient solver of Helmholtz equation is still a big challenge especially in the case of high ***,deep learning has shown great potential in solving PDEs especially in learning solution *** by Neumann series in Helmholtz equation,the authors design a novel network architecture in which U-Net is embedded inside to capture the multiscale *** experiments show that the proposed NSNO significantly outperforms the state-of-the-art FNO with at least 60%lower relative L^(2)-error,especially in the large wavenumber case,and has 50%lower computational cost and less data ***,NSNO can be used as the surrogate model in inverse scattering *** tests show that NSNO is able to give comparable results with traditional finite difference forward solver while the computational cost is reduced tremendously.

关键词： Helmholtz equation inverse problem neumann series neural network solution operator

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Characteristics and source apportionment of ambient volatile organic compounds and ozone generation sensitivity in urban Jiaozuo,China

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Journal of Environmental sciences 2024年第4期138卷 607-625页

作者： Pengzhao Li Chun Chen Dan Liu Jie Lian Wei Li Chuanyi Fan Liangyu Yan Yue Gao Miao Wang Hang Liu Xiaole Pan Jing Mao State Centre for International Cooperation on Designer low-Carbon and Environmental Materials School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Henan Key Laboratory of Environmental Monitoring Technology Henan Ecological Environment Monitoring and Safety CenterZhengzhou 450046China Jiaozuo Ecological Environment Monitoring center of Henan Province Jiaozuo 454003China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

In recent years,many cities have taken measures to reduce volatile organic compounds(VOCs),an important precursor of ozone(O_(3)),to alleviate O_(3) pollution in China.116 VOC species were measured by online and offline methods in the urban area of Jiaozuo from May to October in 2021 to analyze the compositional *** sources were analyzed by a positive matrix factorization(PMF)model,and the sensitivity of ozone generation was determined by ozone isopleth plotting research(OZIPR)*** results showed that the average volume concentration of total VOCs was 30.54 ppbv and showed a bimodal feature due to the rush-hour traffic in the morning and at *** most dominant VOC groups were oxygenated VOCs(OVOCs,29.3%)and alkanes(26.7%),and the most abundant VOC species were acetone and ***,based on the maximum incremental reactivity(MIR)method,the major VOC groups in terms of ozone formation potential(OFP)contribution were OVOCs(68.09μg/m^(3),31.5%),aromatics(62.90μg/m^(3),29.1%)and alkene/alkynes(54.90μg/m^(3),25.4%).This indicates that the control of OVOCs,aromatics and alkene/alkynes should take *** sources of VOCs were quantified by PMF,including fixed sources of fossil fuel combustion(27.8%),industrial processes(25.9%),vehicle exhaust(19.7%),natural and secondary formation(13.9%)and solvent usage(12.7%).The empirical kinetic modeling approach(EKMA)curve obtained by OZIPR on O_(3) exceedance days indicated that the O_(3) sensitivity varied in different *** results provide theoretical support for O_(3) pollution prevention and control in Jiaozuo.

关键词： Volatile organic compounds(VOCs) Online and offline measurement Ozone formation potential(OFP) Positive matrix factorization(PMF) Ozone isopleth plotting research(OZIPR) Jiaozuo

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Construction and Research Progress of the Chinese Meridian Project in 2022–2023

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空间科学学报 2024年第4期44卷 704-711页

作者： WANG Chi CHEN Zhiqing XU Jiyao National Space Science center Chinese Academy of SciencesBeijing 100190

The Chinese Meridian Project(CMP)is a major national science and technology infrastructure constructed in two *** first phase of the CMP has been operating for more than a solar *** 2022 to 2023,utilizing the monitoring data collected by the CMP,scientists made major breakthroughs in fields of ionosphere,middle and upper atmosphere,and coupling between *** construction of the second phase of the CMP is nearly finished,and the project is expected to operate as a whole in 2025 after national acceptance of the second *** whole project was built in an architecture of so-called“One Chain,Three Networks and Four Focuses”.It is promising to make a three-dimensional observation of the whole solar-terrestrial *** science community is looking forward to the great contribution of the CMP to space weather and space physics research.

关键词： Chinese Meridian Project(CMP) Magnetosphere Ionosphere Middle and upper atmosphere

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Significant effect of ordered micro-domain on cell boundary phase distribution and demagnetization curve squareness of Sm_(2)Co_(17)-type magnet

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Rare Metals 2024年第4期43卷 1724-1735页

作者： Zhuang Liu Hai-Chen Wu Chao-Yue Zhang Chao-Qun Zhu Guo-Xin Chen Huan-Ming Lu Ren-Jie Chen Aru Yan CISRI&NIMTE Joint Innovation center for Rare Earth Permanent Magnets Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China University of Chinese Academy of sciences Beijing100049China Analytical center Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China

Cu-rich cell boundary phase is difficult to precipitate evenly,resulting in a generally poor demagnetization curve squareness for Fe-rich Sm_(2)Co_(17)-type magnet,which is a key factor limiting the further improvement of magnetic energy *** this study,we report that nanoscale strip-like ordered micro-domains distributed in1:7H disordered matrix phase of the solid solution precursor is a new factor significantly affecting the precipitation and distribution of the cell boundary *** strip-like and continuous micro-twin structure with twin boundaries neatly perpendicular to the C-axis is observed after sintering *** solution treatment,sequential and long strip-like micro-twins gradually transform into disordered state along the basal plane,forming narrow disordered 1:7H(TbCu_(7)-type structure)phase between the separated strip-like ordered *** disordering transformation takes place via broken down of the long strip-like ordered micro-domains,which is accomplished by narrowing along the width direction followed by reduction of the ***,a new model revealing the effect of the ordered micro-domains on the formation of the cell boundary phase is *** boundaries enriched in Cu have already existed in the precursor with long strip-like ordered ***,the Cu-rich cell boundary phase acting as strong pinning centers cannot be precipitated homogeneously and distributed continuously after aging,resulting in a poor demagnetization curve squareness of Sm_(2)Co_(17)-type *** results indicate that significant broken down of the nanoscale ordered micro-domains in solution precursor is the key factor improving the distribution of cell boundary phase in Sm_(2)Co_(17)-type magnets.

关键词： Sm_(2)Co_(17) magnets Solution precursor Ordered micro-domains Disordering transformation Cellular structure

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C_(Ar)-Br bond cleavage via cooperative EnT/NHC catalysis: mild access to indolines

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Science China Chemistry 2024年第3期67卷 922-927页

作者： Yi-Xiong Dong Cao-Bo Li Ming-Lei Jin Zhong-Hua Gao Song Ye Beijing National Laboratory for Molecular sciences CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of sciences Beijing 100049China

The cooperative visible-light mediated and NHC-catalyzed dearomative arylation-acylation of N-(2-bromobenzoyl)indoles with aldehydes was developed, affording the corresponding highly functionalized polycyclic indolines in moderate to good yields with exclusive diastereoselectivities. Mechanism investigations support the activation of CAr-Br bond via visible-light mediated energy transfer(EnT) and the following single-electron-transfer(SET) with Breslow intermediate under NHC catalysis to give key aryl radical and ketyl radical. This protocol demonstrates the cleavage of CAr-Br bond under mild cooperative EnT/NHC catalysis.

关键词： energy transfer N-heterocyclic carbenes photocatalysis aryl radicals indolines

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Water-soluble chitosan promotes remediation of Pb-contaminated soil by Hylotelephium spectabile

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 109-122页

作者： Bingxin Guo Yiwei Zhang Junxing Yang Tianwei Qian Junmei Guo Xiaona Liu Yuan Jiao Tongbin Chen Guodi Zheng Wenjun Li Fei Qi College of Environmental Science and Engineering Taiyuan University of TechnologyShanxi Key Laboratory of Earth Surface Processes and Resource Ecological Security in Fenhe River BasinShanxi Engineering Research Center of Low Carbon Remediation for Water and Soil Pollution in Yellow River BasinJinzhong 030600China center for Environmental Remediation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of sciences Beijing 100049China Shanxi Transportation Holding Ecological Environment Co. Ltd.Shanxi 030000China Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China

Water-soluble chitosan(WSC)has been studied for its ability to mobilize soil Pb and promote the phytoremediation by Hylotelephium spectabile in Pb-contaminated *** aimed to clarify the internal mechanism by which wSC impacts phytoremediation by examining plant growth and Pb accumulation performance of *** as well as the Pb form,functional groups,and mineral phases of Pb-contaminated *** effectively decreased soil pH and activated Pb migration in rhizosphere soils,with a considerable increase in water-soluble and acid-extractable Pb by 29%-102%and 9%-65%,respectively,and a clear decreasing trend in reducible and oxidizable ***-transform infrared spectroscopy revealed a significant increase in amino and hydroxyl groups in the soil generated by *** coordination of Pb with amino and hydroxyl groups may play an important role in the formation of Pb complexes and activation of Pb in *** field trials,the application of WSC significantly increased Pb accumulation in *** by 125.44%,reaching 92 g/hm^(2).Moreover,the organic matter and nitrogen in the soils were increased by WSc,which improved the growth conditions of *** obvious growth inhibition was observed in either the pot or field ***,WSC is a promising chelating agent for mobilizing Pb in ***,WSC can be potentially used to boost ***-mediated phytoremediation of Pb-contaminatedfarmland.

关键词： Phytoremediation Pb-contaminated soil Water-soluble chitosan Hylotelephium spectabile Fourier transform infrared spectroscopy

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