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Photochemical multicomponent transformation of acceptor-only diazoalkanes by merging their cycloaddition and carbene reactivities

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Chinese Chemical Letters 2023年第9期34卷 138-142页

作者： Bao-Gui Cai guo-yong xu Jun xuan Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials College of Chemistry&Chemical EngineeringAnhui UniversityHefei 230601China Key Laboratory of Structure and Functional Regulation of Hybrid Materials Ministry of EducationHefei 230601China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China

Herein,we report an efficient photochemical method for the synthesis of poly-substituted pyrazoles through a multicomponent reaction of acceptor-only diazoalkanes,alkynes,and solvents(cyclic ethers or nitriles).The key to this success was driven by the photolysis of acceptor-only diazoalkanes to form free carbene species and the fast in situ[3+2]-cycloaddition formation of nucleophilic N–H pyrazole *** work also serves as an entry to allow future reaction design on the combination of carbene reactivity of diazoalkanes with their other reaction modes.

关键词： Photochemical synthesis Multicomponent reaction Diazoalkanes Carbene Pyrazoles

Time Dependence of Entropy Flux and Entropy Production of a Dissipative Dynamical System Driven by Non-Gaussian Noise

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Communications in Theoretical Physics 2008年第6期49卷 1561-1566页

作者： guo yong-Feng xu Wei LI Dong-Xi XIE Wen-Xian Department of Applied Mathematics Northwestern Polytechnical University Xi＇an 710072 China

A stochastic dissipative dynamical system driven by non-Gaussian noise is investigated. A general approximate Fokker-Planck equation of the system is derived through a path-integral approach. Based on the definition of Shannon＇s information entropy, the exact time dependence of entropy flux and entropy production of the system is calculated both in the absence and in the presence of non-equilibrium constraint. The present calculation can be used to interpret the interplay of the dissipative constant and non-Gaussian noise on the entropy flux and entropy production.

关键词： information entropy entropy flux and entropy production non-Gaussian noise Fokker-Planck equation

Visible Light-Promoted Sulfoxonium Ylides Synthesis from Aryl Diazoacetates and Sulfoxides

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Chinese Journal of Chemistry 2021年第6期39卷 1646-1650页

作者： Juan Lu Lei Li Xiang-Kui He guo-yong xu Jun xuan Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials College of Chemistry&Chemical EngineeringAnhui UniversityHefeiAnhui 230601China Key Laboratory of Structure and Functional Regulation of Hybrid Materials(Anhui University) Ministry of EducationHefeiAnhui 230601 China Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province School of ScienceWestlake University18 Shilongshan RoadHangzhouZhejiang 310024China Institute of Physical Science and Information Technology Anhui UniversityHefeiAnhui 230601China

A visible light-promoted reaction of donor/acceptor diazoalkanes with sulfoxides towards the synthesis of synthetically useful sulfoxonium ylides was *** reaction occurred under sole visible light irradiation without the need of any transition-metals or additives,affording the corresponding sulfoxonium ylides in moderate to good *** success of late-stage modification of natural isolates or drug candidates,scale-up reaction and transformation of sulfoxonium ylides to other useful molecules further rendered the approach valuable.

关键词： Sulfoxonium ylides Synthetic methods Carbene Visible Light Diazo compounds

Transition-metal-free synthesis of 1,4-benzoxazepines via[4+3]-cycloaddition of para-quinone methides with azaoxyallyl cations

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Science China Chemistry 2021年第1期64卷 61-65页

作者： Shuang-Jing Zhou Xiao Cheng Chun-Xia Hu guo-yong xu Wen-Jing Xiao Jun xuan Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials and Key Laboratory of Functional Inorganic Materials of Anhui Province College of Chemistry&Chemical EngineeringAnhui UniversityHefei 230601China Key Laboratory of Structure and Functional Regulation of Hybrid Materials(Anhui University) Ministry of EducationHefei 230601China Key Laboratory of Pesticide&Chemical Biology Ministry of EducationCollege of ChemistryCentral China Normal UniversityWuhan 430079China AInstitute of Physical Science and Information Technology Anhui University.Hefei 230601China

A formal[4+3]-cycloaddition reaction of ortho-hydroxyphenyl-substituted para-quinone methides(p-QMs)with in-situ generated azaoxyallyl cations is *** reaction occurs under very mild reaction conditions(transition-metal free,room temperature,cheap inorganic base)and provides a very efficient route to a series of biologically important 1,4-benzoxazepine derivatives in good to excellent yields.

关键词： 1,4-benzoxazepines para-quinone methides azaoxyallyl cations cycloaddition transition-metal-free

Controllable Preparation of Branched Polyolefins with Various Microstructural Units via Chain-walking Ethylene and Pentene Polymerizations

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Chinese Journal of Polymer Science 2023年第6期41卷 905-914,I0008页

作者： Hong-Ju Liu Wan-Lu Tian Xiao-Yue Wang Tong Lei Pei Li guo-yong xu Chao Li Shao-Jie Zhang Fu-Zhou Wang Institutes of Physical Science and Information Technology School of Computer Science and TechnologyAnhui UniversityHefei 230601China

Branched polyolefins with controllable topology structures were generated from the chain-walking(co)polymerizations of ethylene,1-pentene(1P)and 2-pentene(2P)using Brookhart-typeα-diimine Ni(II)-based catalysts possessing different para-substituted groups,{[(4-R-2-Et-6-Me-C6H2N=C)2Nap]NiBr2,Nap:1,8-naphthdiyl;R=CHMePh,Ni1;R=Ph,Ni2;R=H,Ni3}.The X-ray diffraction analysis demonstrated that the crystalline structure of Ni1′is in centrosymmetric dimer structure mode with the bimetallic Ni center connected by two bromide *** para-sec-phenethyl moiety in the catalyst Ni1 obviously improved its catalytic performance and thermal stability in the ethylene *** Ni1/Et2AlCl system showed great catalytic activities(up to 7.73×106 g·mol-1·h-1)and achieved polyethylene(PE)with alkyl chains,including Me,Et,n-Pr,n-Bu,sec-Bu branches and longer chains(Lg).Compared with the 1-pentene polymerization,this catalyst system successfully mediated the polymerization of 2P to give highly branched polymers with approximately 195 branches/1000C possessing Me,Et,and n-Pr branches and a long methylene sequence due to the monomer *** Et branches derived from 2,3-insertion is slightly less than the sum of Me and n-Pr branches derived from 3,2-insertion,indicating that the 3,2-insertion mode is a slightly favorable pathway in the polymerization of 2P.

关键词： polymerization insertion chains

Efficient Mechanisms to Improve TCP Performance over OBS Networks

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China Communications 2010年第2期7卷 87-91页

作者： Hong Xiaobin, Zhou Jun, Wu Jian, guo Hongxiang, Zuo yong, xu Kun, Lin Jintong Key Laboratory of Information Photonics and Optical Communications, Ministry of Education Institute of Optical Communications and Optoelectronics, Beijing University of Posts and Telecommunications, Beijing 100876, China Key Laboratory of Information Photonics and Optical Communications Ministry of Education Institute of Optical Communications and Optoelectronics Beijing University of Posts and Telecommunications

Transmission Control Protocol (TCP) performance over Optical Burst Switching (OBS) is experimentally investigated on an OBS network testbed, concluding that burst losses will lead to a significant drop in the available TCP bandwidth. Two mechanisms are introduced to improve TCP performance. One is concerning the burst assembly optimization and another is based on the novel assembly and scheduling mechanism to reduce the burst losses.

关键词： OBS ACK TCP burst loss probability scheduling algorithm

Reducing the measurement errors in nonadiabatic holonomic quantum computers

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 64-70页

作者： guo-Fu xu Department of Physics Shandong University

Nonadiabatic holonomic quantum computers serve as the physical platform for nonadiabatic holonomic quantum *** quantum computation has entered the noisy intermediate-scale era, building accurate intermediate-scale nonadiabatic holonomic quantum computers is clearly necessary. Given that measurements are the sole means of extracting information, they play an indispensable role in nonadiabatic holonomic quantum computers. Accordingly, developing methods to reduce measurement errors in nonadiabatic holonomic quantum computers is of great importance. However, while much attention has been given to the research on nonadiabatic holonomic gates, the research on reducing measurement errors in nonadiabatic holonomic quantum computers is severely lacking. In this study, we propose a measurement error reduction method tailored for intermediate-scale nonadiabatic holonomic quantum computers. The reason we say this is because our method can not only reduce the measurement errors in the computer but also be useful in mitigating errors originating from nonadiabatic holonomic gates. Given these features,our method significantly advances the construction of accurate intermediate-scale nonadiabatic holonomic quantum computers.

关键词： quantum holonomy quantum computation measurement errors

Deciphering the role of ultra-low-loaded rhodium in NiFe-MIL-53 for superior oxygen evolution reaction

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Journal of Energy Chemistry 2025年第1期100卷 77-86页

作者： Jinzhi Jia Jinhua Zhang Kailu guo Lanyue Zhang Gening Du Hao You Junfeng Huang Mudong Tu Hua Li yong Peng Wei Dou Cailing xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering School of Materials and Energy Lanzhou University College of Chemistry and Chemical Engineering Luoyang Normal University

Designing highly active and stable electrocatalysts of oxygen evolution reaction （OER） is one of the crucial *** this study,a novel OER electrocatalyst,NiFe-MIL-53 modified with ultra-low rhodium（Rh@NiFe-MIL-53）,is successfully prepared via the hydrothermal ***-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active *** importantly,the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe（OH）2after doping Rh is beneficial for improving the electrochemical stability of the catalyst.X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@***,theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap,regulates the d-band center （εd）,accelerates the charge transfer,and optimizes the adsorption behavior of oxygen-containing intermediates,thereby lowering the energy barrier of rate-determining ***,the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity （240 mV） with a small Tafel slope of 48.2 mV dec-1and long-term durability (over1270 h at 10 m A cm-2and 110 h at 200 mA cm-2).This work presents a new perspective on designing highly efficient OER electrocatalysts.

关键词： NiFe-MIL-53 Rh Electrochemical reconstruction Catalytic mechanism Oxygen evolution reaction

农民合作社“农超对接”对接关系稳定性及其影响因素分析

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商业经济与管理 2017年第10期 13-23页

作者：郭锦墉徐磊江西农业大学人文与公共管理学院江西南昌330045 江西农业大学经济管理学院江西南昌330045

文章基于"农超对接"的"SSCP范式"理论分析框架,采用江西省农民合作社的抽样调查数据,研究农民合作社"农超对接"对接关系稳定性及其影响因素。首先,采用生存分析法,分析农民合作社"农超对接"对接关系稳定性情况;然后,运用COX比例风险模型... 详细信息

文章基于"农超对接"的"SSCP范式"理论分析框架,采用江西省农民合作社的抽样调查数据,研究农民合作社"农超对接"对接关系稳定性及其影响因素。首先,采用生存分析法,分析农民合作社"农超对接"对接关系稳定性情况;然后,运用COX比例风险模型,分析农民合作社"农超对接"对接关系稳定性的影响因素。研究结果表明:主营水产的合作社、示范合作社、政府领办的合作社"农超对接"对接关系稳定性更强;政府政策实施效果、合作社能力是影响合作社"农超对接"对接关系稳定性的最显著因素。因此,政府应该分类指导合作社参与"农超对接";各级政府保障相关政策的贯彻落实;合作社加强自身能力提升,平衡与超市间的对接关系。

关键词：合作社 “农超对接” 关系稳定性生存分析 COX模型