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Three-dimensional conjugated macrocycle with large polyaromatic blocks constructed by post-π-extension

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Science China Chemistry 2020年第11期63卷 1626-1631页

作者： Shun-He Liu Hao Hou Ze-Ying Deng Xin-Rong Wang Chun tang Yang-Yang Ju Liu-Bin Feng yuan-zhi tan State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China

Generally,the conjugated homo-macrocycles(CHMs)are synthesized by covalently linking the repeating ***,large subunits are often difficult to conjugate together due to severe ***,large polyaromatic blocks can not only incorporate its appealing electronic and optical properties into CHMs but also distort the CHMs from planar to three-dimensional(3D)molecular *** we synthesized the 3D CHM composed of large polyaromatic units by post-π-***,cyclo-m-phenylenes,as the cyclic precursor,wereπ-extended by C-C coupling and then subjected to dehydrocyclization,affording cyclo-1,3-dibenzo[e,l]pyrenylenes(CMDP).The structures of CMDPs were unambiguously characterized by single crystal X-ray diffraction,showing a congested and strained 3D conformation,which was also confirmed by theoretical *** with the monomer,CMDPs showed redshifted absorption and emission,as well as a ten-fold enhancement in photoluminescence quantum yield,which could be attributed to their 3D conformation.

关键词： macrocycle 7r-extension polyaromatic photoluminescence

Electrochemical hydrogen-storage capacity of graphene can achieve a carbon-hydrogen atomic ratio of 1:1

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Science China Chemistry 2022年第2期65卷 318-321页

作者： Quanfeng He Lanping Zeng Lianhuan Han Juan Peng Matthew M.Sartin yuan-zhi tan Dongping Zhan Zhong-Qun Tian State Key Laboratory of Physical Chemistry of Solid Surfaces Fujian Science&Technology Innovation Laboratory for Energy Materials of ChinaEngineering Research Center of Electrochemical Technologies of Ministry of EducationGraphene Industry and Engineering Research InstituteDepartment of ChemistryCollege of Chemistry and Chemical EngineeringDepartment of Mechanical and Electrical EngineeringSchool of Aerospace EngineeringXiamen UniversityXiamen 361005China Department of Chemistry College of Chemistry and Chemical EngineeringNingxia UniversityYinchuan 750021China

As a promising hydrogen-storage material,graphene is expected to have a theoretical capacity of 7.7 wt%,which means a carbon-hydrogen atomic ratio of 1:***,it has not been demonstrated yet by experiment,and the aim of the *** of Energy is to achieve 5.5 wt%in *** designed a spatially-confined electrochemical system and found that the storage capacity of hydrogen adatoms on single layer graphene(SLG)is as high as 7.3 wt%,which indicates a carbon-hydrogen atomic ratio of 1:1 by considering the sp^(3) defects of ***,SLG was deposited on a large-area polycrystalline platinum(Pt)foil by chemical vapor deposition(CVD);then,a micropipette with reference electrode,counter electrode and electrolyte solution inside was impacted on the SLG/Pt foil(the working electrode)to construct the spatially-confined electrochemical *** SLG-uncovered Pt atoms act as the catalytic sites to convert protons(H^(+))to hydrogen adatoms(H_(ad)),which then spill over and are chemically adsorbed on SLG through surface diffusion during the cathodic *** the electrode processes are reversible,the H_(ad) amount can be measured by the anodic stripping *** is the first experimental evidence for the theoretically expected hydrogen-storage capacity on graphene at ambient environment,especially by using H+rather than hydrogen gas(H_(2))as the hydrogen source,which is of significance for the practical utilization of hydrogen energy.

关键词： graphene hydrogen storage surface electrochemistry adsorption desorption spillover surface diffusion

Supramolecular assembly of functionalized curved carbon-rich molecules

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Supramolecular assembly of functionalized curved carbon-rich...

Highly coupled off-resonance lattice design in diffraction-limited light sources

全国第十九届大环化学暨第十一届超分子化学学术讨论会

作者： yuan-zhi tan Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University

Aromatic carbon-rich molecules(CRMs) show fascinating electronic properties, which are promising in organic electronics, photovoltaics, sensing [1].The nature of sp hybrid carbon prefers the planar geometrical structure, however, introducing additional strain to carbon framework can distort the planar structure, resulting in curved ***, incorporating non-hexagonal rings

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Nuclear Science and Techniques 2024年第9期35卷 92-102页

作者： Yi-Hao Gong Shun-Qiang Tian Xin-Zhong Liu Shou-zhi Xuan Li-yuan tan Ling-Long Mao Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201204 ShanghaiChina Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 ShanghaiChina University of Chinese Academy of Sciences 100049 BeijingChina

The round-beam operation presents many benefits for scientific experiments regarding synchrotron radiation and the weak-ening influences of intra-beam scattering in diffraction-limited synchrotron light sources.A round-beam generation method based on the global setting of skew quadrupoles and the application of a non-dominated sorting genetic algorithm was pro-posed in this *** schemes,including large-emittance coupling introduced via betatron coupling and vertical disper-sion,were explored in a candidate lattice for an upgrade-proposal of the Shanghai synchrotron radiation *** variations with lattice imperfections and their influence on the beam dynamics of beam optic distortions were *** results demonstrated that a precise coupling control ranging from 10 to 100%was achieved under low optical distortion,whereas full-coupling generation and its robustness were achieved by our proposed method by adjusting the skew quadrupole components located in the dispersion-free *** Touschek lifetime increased by a factor of 2–2.5.

关键词： Diffraction-limited storage ring(DLSR) Shanghai synchrotron radiation facility upgrade(SSRF-U) Round beam Off-resonance coupling

Growth process,defects,and dopants of bulkβ-Ga_(2)O_(3)semiconductor single crystals

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China Foundry 2024年第5期21卷 491-506页

作者： Yan-shen Wang Ming-zhi Zhu yuan Liu School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology(Ministry of Education) Beijing 100084China

β-gallium oxide(β-Ga2O3),as the typical representative of the fourth generation of semiconductors,has attracted increasing attention owing to its ultra-wide bandgap,superior optical properties,and excellent tolerance to high temperature and *** to the single crystals of other semiconductors,high-quality and large-sizeβ-Ga_(2)O_(3)single crystals can be grown with low-cost melting methods,making them highly *** this review,the growth process,defects,and dopants ofβ-Ga_(2)O_(3)are primarily ***,the growth process(e.g.,decomposition,crucible corrosion,spiral growth,and development)ofβ-Ga_(2)O_(3)single crystals are summarized and compared in ***,the defects ofβ-Ga_(2)O_(3)single crystals and the influence of defects on Schottky barrier diode(SBD)devices are emphatically ***,the influences of impurities and intrinsic defects on the electronic and optical properties ofβ-Ga_(2)O_(3)are also briefly *** this comprehensive analysis,the article offers a concise summary of the current state,challenges and prospects ofβ-Ga_(2)O_(3)single crystals.

关键词： β-Ga_(2)O_(3) single-crystal growth defects dopants semiconductor

Boundary Points,Minimal L^(2)Integrals and Concavity PropertyⅢ—Linearity on Riemann Surfaces and Fibrations over Open Riemann Surfaces

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2091-2152页

作者： Qi An GUAN zhi Tong MI Zheng yuan School of Mathematical Sciences Peking UniversityBeijing 100871P.R.China School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044P.R.China Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190P.R.China

In this article,we consider a modified version of minimal L^(2) integrals on sublevel sets of plurisubharmonic functions related to modules at boundary points,and obtain a concavity property of the modified *** applications,we give characterizations for the concavity degenerating to linearity on open Riemann surfaces and on fibrations over open Riemann surfaces.

关键词： Minimal L^(2)integrals plurisubharmonic functions boundary points weakly pseudoconvex Kähler manifold

Single-atom Ag-loaded carbon nitride photocatalysts for efficient degradation of acetaminophen:The role of Ag-atom and O_(2)

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Journal of Environmental Sciences 2024年第5期139卷 12-22页

作者： Yi yuan Wen-Long Wang zhi-Wei Wang Jin Wang Qian-yuan Wu Key Laboratory of Microorganism Application and Risk Control of Shenzhen Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental SafetyInstitute of Environment and EcologyShenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Shenzhen Environmental Science and New Energy Technology Engineering Laboratory Tsinghua-Berkeley Shenzhen InstituteShenzhen 518055China College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071China

Carbon nitride has been extensively used as a visible-light photocatalyst,but it has the disadvantages of a low specific surface area,rapid electron-hole recombination,and relatively low light *** this study,single-atom Ag was successfully anchored on ultrathin carbon nitride(UTCN)via thermal polymerization,the catalyst obtained is called *** Ag hardly changed the carbon nitride's layered and porous physical *** exhibited efficient visible-light photocatalytic performances in the degradation of various recalcitrant pollutants,eliminations of 85% were achieved by visible-light irradiation for *** with Ag improved the photocatalytic performance of UTCN by narrowing the forbidden band gap from 2.49 to 2.36 e V and suppressing electron-hole pair *** addition,Ag doping facilitated O_(2) adsorption on UTCN by decreasing the adsorption energy from -0.2 to -2.22 e V and favored the formation of O_(2)^(·-).Electron spin resonance and radical-quenching experiments showed that O_(2)^(·-)was the major reactive species in the degradation of Acetaminophen(paracetamol,APAP).

关键词： Ag single atom Carbon nitride Photocatalysis Visible light Adsorption energy Reactive species

Enhancing whole yeast genome rearrangements through multiple LoxPsym sequences

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Science China(Life Sciences) 2024年第9期67卷 2045-2047页

作者： Bing-zhi Li Ying-Jin yuan Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Frontiers Research Institute for Synthetic Biology Tianjin UniversityTianjin 300072China

Genomic rearrangements play a significant role in disease,evolution,and tumorigenesis(Mani and Chinnaiyan,2010).While single nucleotide polymorphisms(SNPs)and small insertions/deletions contribute substantially to gen... 详细信息

关键词： insertion sequences

Constructing highly safe and long-life calcium ion batteries based on hydratedvanadium oxide cathodes featuring a pillar structure

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Rare Metals 2024年第6期43卷 2597-2612页

作者： Chun-Fang Wang Shi-Wei Zhang Lan Huang yuan-Min Zhu Feng Liu Jian-Chuan Wang Li-Ming tan Chun-Yi zhi Cui-Ping Han Powder Metallurgy Research Institute Central South UniversityChangsha410083China Songshan Lake Materials Laboratory Dongguan 523808China Research Institute of Interdisciplinary Science and School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China Faculty of Materials Science and Energy Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Calcium-ion batteries(CIBs)have generated intense interest due to the growing demand for safer,cheaper,and large-scale energy storage ***,their development is still in its infancy,owing to the lack of suitable cathodes for sustaining reversiblc Ca^(2+)intercalation/***,layered H_(2)V_(3)O_(8)(HVO)with Zn^(2+)pre-insertion(ZHVO)is reported as a high-rate and highly durable cathode material for *** existence of Zn^(2+)and H_(2)O pillars could expand the interlayer spacing up to 1.8 nm,which is favorable for the diffusion of bulky Ca^(2+).The formation of Zn-O bonds facilitates electron transfer and enhances electrical ***,the ZHVO cathode achieves superior capacity performance(213.9 mAh·g^(-1)at 0.2 A·g^(-1))and long lifespan(78.3%for 1,000 cycles at 5 A·g^(-1))compared to pristine *** functional theory(DFT)calculations revealed that Zn^(2+)moved during Ca^(2+)intercalation,thereby reducing the diffusion energy barrier and facilitating Ca^(2+)***,a safe aqueous calcium ion cell was successfully assembled.

关键词： Multivalent batteries Calcium-ion batteries Layered structure Vanadium oxide Cathode materials