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An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality

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Science China Chemistry 2024年第9期67卷 2998-3003页

作者： Qi liu xue-dong li liang Cheng li liu Beijing National Laboratory for Molecular Sciences(BNLMS) 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 central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which provides efficient methods for the preparation of axially chiral ***,developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination *** this work,we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent *** addition,the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis *** methodology provided a straightforward and sustainable access to a broad range of biaryl-2-carboxylic acid and in excellent yields(up to 92%)and excellent central-to-axial chirality conversion(up to 99%conversion percentage).This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization.

关键词： br?nsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion

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Fe(NO_3)_3-9H_2O-catalyzed aerobic oxidation of sulfides to sulfoxides under mild conditions with the aid of trifluoroethanol

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Chinese Chemical Letters 2015年第5期26卷 539-542页

作者： xue-dong li Ran Ma liang-Nian He State Key Laboratory of Elemento-Organic Chemistry Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Nankai University

Selective oxidation of sulfides to sulfoxides was successfully performed by employing readily available Fe（NO3）3-9H2O as the active catalyst with oxygen as the oxidant in 2,2,2-trifluoroethanol （TFE） without the formation of sulfones. Nitrate anion could play a crucial role in promoting the reaction due to the oxidation capacity under acidic media. High yields of sulfoxides were exclusively obtained from the corresponding sulfides. Furthermore, both aromatic and aliphatic sulfides gave moderate to high yields of sulfoxides with this protocol.

关键词： FeiNO3)3.9H2O TFE Oxidation Sulfox[des

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The Effect of the Relative Velocity on Traffic Flow

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Communications in Theoretical Physics 2002年第8期38卷 230-234页

作者： xue Yu dong li-Yun YUAN Yi-Wu DAI Shi-Qiang Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China Department of Physics Guangxi University Nanning 530003 China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

The optimal velocity model of traffc is extended to take the relative velocity into account. The traffcbehavior is investigated numerically and analytically with this model. It is shown that the car interaction with therelative velocity can effect the stability of the traffic flow and raise critical density. The jamming transition between thefreely moving and jamming phases is investigated with the linear stability analysis and nonlinear perturbation *** traffic jam is described by the kink solution of the modified Korteweg-de Vries equation. The theoretical result isin good agreement with the simulation.

关键词： optimal velocity model, relative velocity, jamming transition, traffic flow

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Inhibitory effect of tenomodulin versus ranibizumab on in vitro angiogenesis

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International Journal of Ophthalmology(English edition) 2017年第8期10卷 1212-1216页

作者： Wei Wang Guang-Xu liu Yue-Hua li xue-dong li Yan He Department of Ophthalmology Beijing Chao-Yang HospitalCapital Medical University Department of Epidemiology and Health Statistics School of Public HealthCapital Medical University

AIM： To evaluate anti-angiogenic effect of tenomodulin （TNMD） and ranibizumab on cell proliferation and capillary- like morphogenesis of vascular endothelial cells under the stimulation of vascular endothelial growth factor （VEGF） in vitro. METHODS： The effects of TNMD and ranibizumab on VEGF-induced proliferation of human umbilical vein endothelial cells （HUVECs） were evaluated by MTT assay, and the effects of TNMD and ranibizumab on capillary- like structures formed by HUVECs under the stimulation of VEGF were examined in culture. Capillary-like morphogenesis of HUVECs was quantitatively evaluated, and total lengths of tube-like structures per field were measured in a masked way. RESULTS： HUVECs with both ranibizumab and TNMD protein showed MTT reduction in VEGF-stimulated cell proliferation as expected, while MTT absorbance in the HUVECs with TNMD was significantly declined than that with ranibizumab （P〈O.01）. The capillary-like structures formed by HUVECs were markedly impaired by the presence of both TNMD and ranibizumab in the culture medium. The total length of the capillary-like structures per field was significantly shorter in the medium with TNMD than that of ranibizumab （P〈0.01）. The inhibitory effect of TNMD on tube formation in vitro angiogenesis was significantly stronger than that of ranibizumab. CONCLUSION： TNMD may have stronger inhibitory effect than ranibizumab on in vitro angiogenesis.

关键词： tenomodulin ranibizumab inhibitory effect proliferation angiogenesis

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Facile molybdenum and aluminum recovery from spent hydrogenation catalyst

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Chinese Journal of Chemical Engineering 2024年第5期69卷 72-78页

作者： Zhenhui Lv Jianan li dong xue Tao Yang Gang Wang Chong Peng State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024China Dalian Research Institute of Petroleum and Petrochemicals SINOPECDalian 116041China

Industrial catalyst waste has emerged as a hazardous pollutant that requires safe and proper disposal after the unloading *** a valuable and sustainable strategy for its treatment is a significant challenge compared to traditional *** this study,we present a facile method for the recovery of molybdenum and aluminum contents from spent Mo-Ni/Al_(2)O_(3) hydrogenation catalysts through crystallization separation and ***,the recovered molybdenum and aluminum are utilized as active metals and carriers for the preparation of new *** properties were thoroughly analyzed and investigated using various characterization *** hydrogenation activity of these newly prepared catalysts was evaluated on a fixed-bed small-scale device and compared with a reference catalyst synthesized from commercial raw ***,the hydrogenation activity of the catalysts was further assessed by using the entire distillate oil of coal liquefaction as the raw oil,specifically focusing on denitrogenation and aromatic *** work not only offers an effective solution for recycling catalysts but also promotes sustainable development.

关键词： Waste treatment Alumina Hydrogenation Catalyst Crystallization Precipitation

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Effect of Bimodal Quasicrystal Phase on the Dynamic Recrystallization of Mg–Zn–Gd Alloy during High-Pressure Torsion

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1128-1134页

作者： Ping li Shuangwu Xia Junfu dong liangwei Dai Zhicheng Luo Kemin xue School of Material Science and Engineering Hefei University of TechnologyHefei230009China

The Mg–Zn–Gd alloy with quasicrystal icosahedral phase was processed by high-pressure torsion (HPT). The effect of bimodal I-phase on the dynamic recrystallization was analyzed by transmission electron microscopy. The results showed that the block I-phase can stimulate obvious particle-stimulated nucleation and dynamic recrystallization (DRX) grains were preferentially formed after HPT for 5 turns, while the granular I-phase only promoted the generation of sub-grains. The orientation relationship was determined as twofold//[1210] and fivefold//(0002)_(Mg). Moreover, after HPT for 9 turns, the DRX grains induced by block I-phase appeared to grow up and coarsened. Compared with block I-phase, the grains induced by granular I-phase presented much smaller size and distributed more homogeneous due to the strong pinning effect.

关键词： High-pressure torsion(HPT)-Quasicrystal phase Dynamic recrystallization Particle-stimulated nucleation Orientation relationship

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Photocatalytic vinyl radical-mediated multicomponent 1,4-/1,8-carboimination across alkynes and olefins/(hetero)arenes

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Science China Chemistry 2024年第2期67卷 558-567页

作者： Shan-Shan li Yu-Shi Jiang xue-ling Luo Xuming Ran Yuqiang li dong Wu Cheng-xue Pan Peng-Ju Xia School of Chemistry and Pharmaceutical Sciences Guangxi Normal UniversityGuilin541004China Shanghai Artificial Intelligence Laboratory Shanghai200433China The Institute for Advanced Studies Wuhan UniversityWuhan430064China

We developed a highly selective and efficient multicomponent transformation by utilizing alkynes and olefins/(hetero)arenes through photoinduced energy-transfer *** reaction involves the formation of three distinct chemical bonds,namely C(sp~3)–C(sp~2),C(sp~2)–C(sp~3),and C(sp~3)–N,in a single coordinated *** strategy used a vinyl radical-mediated radical relay approach under mild conditions,exhibiting a broad substrate scope(>70 examples),excellent functional-group tolerance,and remarkable regio-and *** the utilization of a combination of experimental techniques and density functional theory(DFT),we delved deeper into the mechanistic intricacies of this distinctive *** revealed that the selective radical addition to electron-deficient alkynes,rather than olefins,was governed by the inherent reactivity of alkyl *** discovery presented a highly effective approach for the synthesis of stereodefined multisubstituted alkenes.

关键词： alkyne-olefin coupling DFT studies regio-and anti-stereoselectivity multisubstituted alkenes

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Unraveling role of double-exchange interaction in electrochemical water oxidation by external magnetic field

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Rare Metals 2024年第1期43卷 289-297页

作者： Jun li Jun-Ming li Hong Hong dong-xue liu Qing-Qi Cao Dun-Hui Wang National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory for Nanotechnology Nanjing UniversityNanjing 210093China School of Electronics and Information Hangzhou Dianzi UniversityHangzhou 310018China

Double-exchange(DE) interaction plays an important role in electrocatalytic oxygen evolution reaction(OER).However,precise achievement of DE interaction often requires foreign dopants or vacancy engineering,leading to destabilization of the catalysts and deterioration of *** contrast,the utilization of environmentally friendly,contactless,and continuously adjustable magnetic fields to study the OER process is profitable to avoid aforementioned interference factors and further elucidate the direct relationship_(0.5)between DE interaction and OER ***,by using cobalt hydroxide carbonate(Co(OH)(CO_(3))·xH_(2)O,CoHC) nanostructures as a proof-of-concept study,external magnetic fields are carefully implemented to verify the role of DE interaction during water oxidation *** studies reveal that external magnetic fields effectively enhance the reaction rate of the catalyst,the overpotential decreases from 386 to 355 mV(100 mA·cm^(-2)),while Tafel slopes drastically decline from 93 to 67 mV·dec^(-1)(1.0 T).Moreover,magnetic field increment exhibits robust *** in situ Raman and impedance measurements under external field,it can be found that magnetic field promotes the electron migration between Co^(2+) and Co^(3+) in the CoHC catalysts with the assistance of DE interactions,thus boosting the OER efficiency.

关键词： Magnetic field Double-exchange(DE)interaction Electrocatalysis Oxygen evolution reaction(OER) Cobalt hydroxide carbonate

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Biomimetic design of highly flexible metal oxide nanofibrous membranes with exceptional mechanical performance for superior phosphopeptide enrichment

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Nano Research 2024年第5期17卷 4270-4278页

作者： xue Mao Zhen-Zhen li dong-lian Hao Wei-dong Han Gao-Peng li Yao-Yu Wang Kun Zhang School of Textile Science and Engineering Key Laboratory of Functional Textile Material and Product(Ministry of Education)Xi’an Polytechnic UniversityXi’an 710048China Key Laboratory of Magnetic Molecules&Magnetic Information Materials of the Ministry of Education School of Chemistry&Material ScienceShanxi Normal UniversityTaiyuan 030031China Department of Clinical Laboratory The Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710004China Shanghai iProteome Biotechnology Co. LtdShanghai 201210China College of Chemistry&Materials Science Northwest UniversityXi'an 710127China

Developing free-standing and mechanical robust membrane materials capable of superior enrichment of phosphopeptides for analyzing and identifying the specific phosphoproteome of cancer cells is significant in understanding the molecular mechanisms of cancer development and exploring new therapeutic approaches,but still a significant challenge in materials *** this end,we firstly constructed highly flexible ZrTiO_(4) nanofibrous membranes(NFMs)with excellent mechanical stability through a cost-effective and scalable electrospinning and subsequent calcination ***,to further increase the enrichment capacity of the phosphopeptide,the biomimetic TiO_(2)@ZrTiO_(4) NFMs with root hair or leaf like branch microstructure are developed by the hydrothermal post-synthetic modification of ZrTiO_(4) NFMs through growing unfurling TiO_(2) nanosheets onto the ZrTiO_(4) ***,remarkable flexibility and mechanical stability enable the resulting TiO_(2)@ZrTiO_(4) NFMs excellent practicability,while the biomimetic microstructure allows it outstanding enrichment ability of the phosphopeptide and identification ability of the specific phosphoproteins in the digest of cervical cancer ***,6770 phosphopeptides can be enriched by TiO_(2)@ZrTiO_(4) NFMs(2205 corresponding phosphoproteins can be identified),and the value is much higher than that of ZrTiO_(4) NFMs(6399 phosphopeptides and 2132 identified phosphoproteins)and commercial high-performance TiO_(2) particles(4525 phosphopeptides and 1811 identified phosphoproteins).These results demonstrate the super ability of TiO_(2)@ZrTiO_(4) NFMs in phosphopeptide enrichment and great potential for exploring the pathogenesis of cancer.

关键词： inorganic nanofibers flexible ceramic nanofibrous membranes biomimetic materials exceptional mechanical performance flexibility

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Enhanced hydrogen evolution reaction in FePt film with remanence due to decrease in domain walls

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Rare Metals 2024年第3期43卷 1108-1115页

作者： Hong Hong dong-xue liu Jun li Jun-Ming li li-Qian Wu Bo Yang Qing-Qi Cao Dun-Hui Wang National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced MicrostructuresJiangsu Provincial Key Laboratory for NanotechnologySchool of PhysicsNanjing UniversityNanjing210093China Hangzhou Dianzi University Hangzhou310018China Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang110819China

As an effective strategy to improve the properties of electrocatalysts,magnetic field-assisted electrocatalytic water splitting has attracted increasing attention ***,the corresponding enhancements mostly depend on the exertion of an external magnetic field during electrochemical reactions,which results in a high cost of industrial production,and makes the magnetic field manipulation of electrocatalysis become a challenging *** this work,instead of the external magnetic field,a bias magnetic field is self-supplied by the remanence state of a ferromagnetic electrocatalyst of *** to the assistance of this bias magnetic field,the FePt film in the remanence state shows the overpotential of 229 mV during hydrogen evolution reaction,which is much lower than that in its demagnetization state(283 mV).Our findings demonstrate that the remanence in ferromagnetic electrocatalysts can improve the catalytic performance,which is attributed to the decrease in domain walls.

关键词： Remanence Magnetic domains Electrocatalysis Hydrogen evolution reaction(HER)

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