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Chemoselective epoxidation of electron-deficient olefins with molecular oxygen via conjugated olefins epoxidation and BHT hydroxylation

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Science China Chemistry 2024年第9期67卷 3012-3018页

作者： jia nie Huanfeng jiang Chuanle Zhu School of Chemistry and Chemical Engineering Key Lab of Functional Molecular Engineering of Guangdong ProvinceSouth China University of TechnologyGuangzhou 510640China Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing South China University of TechnologyGuangzhou 510640China

The chemoselective epoxidation of electron-deficient olefins in the presence of electron-rich alkene moieties is *** chemoselective epoxidation strategy undergoes a conjugated olefin epoxidation and BHT hydroxylation process to give various useful oxiranes in high yields,especially for the 2-substituted ***,this protocol features mild conditions,is transition-metal free,operationally simple,and gram-scalable,and tolerates diverse functional *** candidate HSD-16 is synthesized smoothly by this *** studies indicate molecular oxygen is the terminal oxidant and the O-source of the oxiranes.

关键词： chemoselective epoxidation alkene fluorine molecular oxygen

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Ameliorating the Strength-Modulus Synergy in GNPs Reinforced Mg-Zn-Zr Composites via Multidirectional Forging and Hot Extrusion Deformation

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 425-437页

作者： Yuhao Chen Kaibo nie Kunkun Deng Zhilong Liu Quanxin shi College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Compressor Technology(Compressor Technology Laboratory of Anhui Province) Hefei 230031China Instrumental Analysis Center Taiyuan University of TechnologyTaiyuan 030024China

The integration of lightweight and high-modulus magnesium-based materials is becoming increasingly valued as structural materials due to the complexity and intelligence of industrial products like automobiles and *** this study,the graphene nanoplatelets(GNPs)/Mg-Zn-Zr composites with 0.5 wt%GNPs were successfully prepared by the combination of multidirectional forging(MDF)and hot extrusion(Ex).The newly-developed composites after multi-step deformation possessed excellent strength and modulus,with a tensile strength exceeding 375 MPa and an elastic modulus reaching 54 *** results revealed that the stripping and thinning of GNPs bands parallel to the extrusion direction occurred after MDF+Ex,which promoted the dynamic recrystallization and the formation of numerous fine *** significant improvement in comprehensive mechanical performances of the composites could be primarily ascribed to the refinement of grain size caused by the optimized distribution of GNPs,and efficient load transfer facilitated by the tight interface.

关键词： Magnesium matrix composites Graphene nanoplatelets(GNPs) Multi-step deformation Microstructure Strength-modulus

Monitoring of Cell Membrane Microenvironment Based on DNA Nanodevices

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Chemical Research in Chinese Universities 2024年第2期40卷 255-267页

作者： NAN Hexin CAI Ming KUANG shi nie Zhou State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan Provincial Key Laboratory of Biomacromolecular Chemical BiologyHunan UniversityChangsha410082P.R.China

The cell membrane is a critical barrier for cellular homeostasis,integral to signaling and intercellular communication,and vital for understanding cellular functions and disease *** its microenvironment is crucial for uncovering the molecular basis of physiological and pathological processes associated with the cell membrane,driving the development of bioanalytical toolkits capable of dynamically monitoring the cell surface *** the continuous advancement of functional nucleic acids and dynamic DNA nanotechnology,DNA nanodevices with controllable nanosized geometry,specific molecular recognition,and selective membrane-localization properties offer a versatile platform for probing the cell membrane *** this review,we summarize the current biosensing and membrane-anchoring mechanisms of DNA nanodevices and highlight their use in studying key cell membrane events,including membrane lipid dynamics,transmembrane transport,receptor dimerization,and signal ***,we discuss the challenges and potential future applications of DNA nanodevices in advancing cell membrane biology research and biomedical applications.

关键词： DNA nanodevice Cell membrane Cellular micro-environment Monitoring

Facile synthesis of W-Mo bimetallic oxides with high adsorption properties from secondary resources

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Tungsten 2024年第4期6卷 806-820页

作者： jia-Li Cheng Yang-Si Liu Xiao-Li Xi Zuo-Ren nie Collaborative Innovation Center of Capital Resource-Recycling Material Technology College of Materials Science and Engineering Beijing University of Technology National Engineering Laboratory for Industrial Big-Data Application Technology Beijing University of Technology Key Laboratory of Advanced Functional Materials Ministry of Education Beijing University of Technology

A simple solvothermal method was used to obtain W-Mo bimetallic oxides from W-Mo alloy scrap,and pure metal powders were also used as the raw materials to simulate *** products had a sea urchin-like structure with abundant oxygen vacancies and the products prepared at low temperatures forms a sosoloid resembling orthorhombic *** WMo bimetallic oxide prepared at the reaction temperature of 120 ℃ exhibited excellent selective adsorption performance for methylene blue（MB）,which the adsorption rate of MB reached 99% in 12 min and the adsorption rate reached 90% after6 adsorption *** the W-Mo molar ratio is 1:3,the maximum adsorption capacity of sample for MB can reach1148 mg·*** adsorption process followed the Langmuir and pseudo-second-order models,which is surface-controlled monolayer *** experimental results show the feasibility of preparing W-Mo bimetal oxide products from pure materials and *** process is simple and effective,which offered a potential approach for secondary resource recycling and reusing.

关键词： Oxygen vacancy Selective adsorption Solvothermal W–Mo alloy scrap W–Mo bimetallic oxide

Effect of Sc on Al_(3)Fe phase and mechanical properties of as-cast AA5052 aluminum alloy

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China Foundry 2024年第3期21卷 257-264页

作者： Yang Li Qing Yu Feng-feng Chen jia-wen He Hong-mei Yang Meng-nie Li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical *** studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the *** this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%*** results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc *** ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.

关键词： AA5052 aluminum alloy Al3Fe phase mechanical properties grain boundary

Dual modification of LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2) cathode materials by K^(+) doping and Li_(3)PO_(4) coating for lithium ions batteries

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Rare Metals 2024年第7期43卷 3007-3018页

作者： Wei Xiao jia-Le Wang Zhi-Cheng Yi Cheng-Jin Liu Chang Miao Yu Xin Shu-Qing nie College of Chemistry and Environmental Engineering Yangtze UniversityJingzhou 434023China

Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the lattice to widen the(003) plane to 0.4746 nm with a lower cationic disordered degree of 1.87%.Moreover,the surface residual lithium salts are treated by H_3PO_4 to generate a uniform Li_(3)PO_(4) coating layer of approximately 11.41 nm,which completely covers on the surface of secondary spherical particles to improve the interfacial *** 25℃,the NCM-KP electrode delivers a discharge specific capacity of 148.9 mAh·g^(-1) with a remarkable capacity retention ratio of 84.1% after 200 cycles at 1.0C and retains a high reversible specific capacity of 154.4 mAh·g^(-1) at *** at 1.0C and 60℃,it can maintain a reversible discharge specific capacity of 114.6 mAh·g^(-1) with 0.21% of capacity decay per cycle after 200 cycles,which is significantly lower than 0.40% for the pristine NCM ***,the charge transfer resistance of 238.89 Ω for the NCM-KP electrode is significantly lower than 947.41 Ω for the pristine NCM one by restricting the interfacial side ***,combining K+doping and Li_(3)PO_(4) coating is an effective strategy to enable the significant improvement of the electrochemical property of high-nickel cathode materials,which may be mainly attributed to the widened diffusion pathway and the formed Li_(3)PO_(4) protective layer,thus promoting Li~+diffusion rate and preventing the erosion of HF.

关键词： High-nickel cathode material Residual lithium K^(+)doping Li_(3)PO_(4)coating Lithium ions battery

Avoiding Sabatier's limitation through pulsed electrocatalysis for enhanced nitrogen oxidation performance

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Journal of Energy Chemistry 2024年第8期95卷 484-489,I0010页

作者： Xiping Guan Zhongfen nie Linlin Zhang Mingxia Guo Chuanwei shi Chunlei Gu Xia Liu Xin Ding College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071ShandongChina State Key Laboratory of Fine Chemicals Dalian University of Technology(DUT)Dalian 116024LiaoningChina

*** The activation and conversion of the Earth’s abundant inert nitrogen resources into high-value-added products epitomize one of nature’s most critical processes[1-3].Nitric acid(HNO_(3)),as a pivotal industrial raw material,showcases an extensive range of applications and possesses substantial economic value in the production of indispensable chemical compounds[4-6].

关键词： value performance abundant

Simulation and evaluation study of atmospheric aerosol nonsphericity as a function of particle size

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Particuology 2024年第7期90卷 281-291页

作者： Qianjun Mao Xin nie School of Urban Construction Wuhan University of Science and TechnologyWuhan430065China College of New Energy and Materials Northeast Petroleum UniversityDaqing163318China

Aerosol nonsphericity causes great uncertainty in radiative forcing assessments and climate *** considerable studies have attempted to quantify this uncertainty,the relationship between aerosol nonsphericity and particle size is usually not considered,thus reducing the accuracy of the *** this study,a coupled inversion algorithm combining an improved stochastic particle swarm optimization algorithm and angular light scattering is used for the nonparametric estimation of aerosol nonsphericity variation with particle size,and the optimal sample selection method is employed to screen the *** on the verification of inversion accuracy,the variation of aerosol aspect ratio with particle size based on the ellipsoidal model in global regions has been obtained from Aerosol Robotic Network(AERONET)data,and the effect of nonsphericity on radiative forcing and dry deposition has been *** results show that the aspect ratio increases with particle size in all regions,with the maximum ranging from 1.4 to 1.8 in the desert,reflecting the differences in aerosol composition at different particle *** radiation calculations,considering aerosol nonsphericity makes the aerosol cooling effect weaker and surface radiative fluxes increase,but hardly changes the aerosol absorption,with maximum differences of 9.22%and 22.12%at the bottom and top of the atmosphere,***,the differences in radiative forcing between aspect ratios as a function of particle size and not varying with particle size are not significant,averaging less than 2%.Besides,the aspect ratio not varying with particle size underestimates the deposition velocity of small particles and overestimates that of large particles compared to that as a function of particle size,with maximum differences of 7%and 4%,respectively.

关键词： Aerosol nonsphericity Inversion Aspect ratio Radiative forcing Dry deposition velocity

Symmetric Brownian motor subjected to Lévy noise

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Chinese Physics B 2024年第2期33卷 222-227页

作者：贾考胡兰聂林如 Faculty of Science Kunming University of Science and TechnologyKunming 650500China

In the past few years,attention has mainly been focused on the symmetric Brownian motor(BM)with Gaussian noises,whose current and energy conversion efficiency are very ***,we investigate the operating performance of the symmetric BM subjected to Lévy *** numerical simulations,it is found that the operating performance of the motor can be greatly improved in asymmetric Lévy *** any load,the Lévy noises with smaller stable indexes can let the motor give rise to a much greater *** a load,the energy conversion efficiency of the motor can be enhanced by adjusting the stable indexes of the Lévy noises with symmetry *** results of this research are of great significance for opening up BM’s intrinsic physical mechanism and promoting the development of nanotechnology.

关键词： symmetric Brownian motor average velocity energy conversion efficiency Lévy noise