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Controlled cationic ring-opening polymerization of l-lactide by organic ion pair: novel approach to isotactic-rich and crystalline polylactide

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Science China Chemistry 2025年第1期68卷 394-402页

作者： zhiqiang ding Mingqian Wang zijing zhou Bin Wang Yuesheng li Tianjin Key laboratory of Composite & Functional Materials School of Materials Science and Engineering Tianjin University

living/controlled cationic ring-opening polymerization （ROP） of l-lactide is a promising approach to isotactic-rich and crystalline poly（l-lactide）.In contrast with the unsubstituted lactones,l-lA can not be polymerized by organic lewis acids or carbenium ions,and the state of the art in this field is the cationic ROP of l-lA catalyzed by Br?nsted acid/alcohol system via activated monomer ***,we reported the first example of controlled cationic ROP of l-lA by using Meerweintype ion pair[Me3O]+[B（C6F5）4]-as the catalyst.[Me3O]+[B（C6F5）4]-promoted rapid l-lA cationic polymerization in the absence of alcohol,producing isotactic-rich and crystalline PllA without transesterification and epimerization side *** activated chain end mechanism,involving twice SN2 substitution and configuration-inversion （S→R→S） with the assistance of released Me2O,was proposed and further verified by density functional theory and control *** work expands the catalytic toolbox of isotactic-rich and crystalline polylactide *** represents a unique example of cationic-controlled polymerization of l-lA catalyzed by an organic ion pair.

关键词： organic ion pair controlled cationic ring-opening polymerization activated chain end mechanism isotactic-rich polylactide

Deciphering the role of mtH2O2 in hepatic ischemia-reperfusion injury mechanisms with low-background super-resolution fluorogenic probe

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Science China Chemistry 2025年第1期68卷 297-307页

作者： Bin Fang limin Wang Haoqin li Jiaxin zhang Yang ding Pan Pan li Bo Peng Hua Bai lin li Frontiers Science Center for Flexible Electronics Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials &Engineering Northwestern Polytechnical University Institute of Flexible Electronics (IFE Future Technologies) Xiamen University

Hepatic ischemia-reperfusion injury（HIRI） is characterized by mitochondrial dysfunction and oxidative stress. Monitoring mitochondrial hydrogen peroxide（mtH2O2） levels in real-time through super-resolution imaging is crucial for elucidating its distribution in live cells and its mechanism of action during HIRI. However, low-background fluorogenic probes have been overlooked in the context of super-resolution imaging. In this study, we developed a low-background fluorogenic probe（MitoWG） with the potential for super-resolution morphology-correlated mitochondrial identification to track the fluctuates of mtH2O2in HIRI. Activation of the desirable fluorescence properties of the probe by mtH2O2was confirmed using structural illumination microscopy（SIM）, enabling high-quality mitochondrial imaging with exceptional specificity and *** in mtH2O2levels were successfully observed in both cellular and rat models of HIRI. Furthermore, we associated the decline in mitochondrial redox homeostasis with accelerated mtH2O2production during HIRI, which triggered mitophagy deficiency and led to cell death. In conclusion, Mito-WG possesses excellent photophysical and low-background properties for SIM imaging, making it a promising tool for mtH2O2tracking in HIRI research and clinical diagnosis.

关键词： hepatic ischemia-reperfusion injury low-background mtH2O2-activatable super-resolution imaging fluorogenic probe

Magnetic/Magnetostrictive Properties Together with Resistivity and Corrosion Behaviors of CoFe_2 and Its Composite with CoFe_2N

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Journal of Materials Science & Technology 2017年第7期33卷 744-750页

作者： B.Q.Geng Y.Q.Ma M.Wang z.l.ding W.H.Song B.C.zhao Key laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China

The CoFe_2alloy（CF） was prepared by reducing CoFe_2O_4 in the H_2 ambient. Subsequently the CF sample was nitrided in the NH_3 atmosphere to produce the composite of CoFe_2N and CoFe_2. The magnetostriction, thermal expansion, resistivity and corrosion resistance of CF sample and the nitrided sample（CFN）at 1000？C were investigated. The saturation magnetostriction coefficiency λ_s and thermal expansion coefficient ？ at 300 K for the nitrided CFN were 50 ppm and 10 ppm/K, respectively, approximately equal to those for the CF sample. However, compared with CF, CFN presents a decrease in temperature coefficient R_λ（300 K） of magnetostriction by 11%. The smaller resistivity and improved corrosion resistance in the H_2SO_4 solution may expand the applications of the CoFe_2 in the fields needing lower resistivity or in the acidic environment.

关键词： CoFe alloy CoFe_2N alloy Magnetostriction Resistivity Corrosion resistance

Pulsed dynamic electrolysis enhanced PEMWE hydrogen production:Revealing the effects of pulsed electric fields on protons mass transport and hydrogen bubble escape

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Journal of Energy Chemistry 2025年第1期100卷 201-214页

作者： Xuewei zhang Wei zhou Yuming Huang liang Xie Tonghui li Huimin Kang lijie Wang Yang Yu Yani ding Junfeng li Jiaxiang Chen Miaoting Sun Shuo Cheng Xiaoxiao Meng Jihui Gao Guangbo zhao School of Energy Science and Engineering Harbin Institute of Technology China Datang Technology Innovation Co. Ltd

The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis （PEMWE） emerging as the preeminent pathway for hydrogen *** remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable *** impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles *** address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis *** to constant voltage electrolysis (hydrogen production rate:51.6 m l h-1,energy consumption:5.37 kWh Nm-3H2),this strategy (hydrogen production rate:66 m l h-1,energy consumption:3.83 kWh Nm-3H2) increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic （PV） system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 *** combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis （PDE） dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode *** such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport *** promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.

关键词： Electrolysis

Mechanisms of High Coercivity in Ni/NiO Composite Films by Post Annealing

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材料科学与工程学报 2007年第6期25卷 858-860页

作者： J.B. Yi J. ding Mansoor Bin Abdul Jalil B.H. liu S. Thongmee J.H. Yin z.l. zhao Department of Materials Science and Engineering National University of Singapore 119260 Singapore Department of Electrical ＆ Computer Engineering National University of Singapore 119260 Singapore

A coercivity as large as 2.4 kOe has been achieved in the Ni/NiO composite film after an annealing under a magnetic field of 10 kOe and an O_2 partial pressure of 0.001 *** coercivity was attributed to the strong exchange coupling of Ni and *** grain size of Ni and NiO was observed after the *** enhanced coercivity is probably associated with the domain wall pinning by local energy minima,the distribution of Ni and NiO,and the domain structure in the interface of Ni/NiO generated under the presence of the magnetic field during the post-annealing.

关键词：矫顽性镍氧化镍复合薄膜焊后退火交换耦合

Interfacial bonding mechanism in Al/coated steel dissimilar refill friction stir spot welds

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Journal of Materials Science & Technology 2019年第6期35卷 1027-1038页

作者： z. Shen Y. ding J. Chen B. Shalch Amirkhiz J.z. Wen l. Fu A.P. Gerlich School of Materials Science and Engineering Northwestern Poly technical University Xi'an 710072 China Shanxi Key laboratory of Friction Welding Technologies Northwestern Polytechnical University Xi'an 710072 China State Key laboratory of Solidification Processing Northwestern Poly technical University Xi'an 710072 China Centre of Advance Materials Joining Department of Mechanical and Mechatronics Engineering University of Waterloo 200 University Ave. Waterloo N2L3G1 Ontario Canada CanmetMATERIAlS Natural Resources Canada Hamilton L8P 0A5 Canada

Defect-free dissimilar Al/zinc coated steel and Al/AlSi coated steel welds were successfully fabricated by refill friction stir spot welding. However, Al alloy and uncoated steel could not be welded under the same welding condition. Al-zn eutectic layer formed at the Al/zinc coated steel interface showed nonuniformity in thickness and nanoscale intermetallic(IMC) produced was discontinuous. The bonding formation between the Al-zn layer and the surrounding materials was attributed to a liquid/solid reaction mechanism. Bonding formation at Al alloy and AlSi coated steel interface was attributed to a solid/solid reaction mechanism, as the joining process did not involve with melting of base metals or AlSi coating materials. Kissing bond formed at the weld boundary acted as a crack initiation and propagation site,and the present study showed that weld strength of Al 5754/AlSi coated steel was greatly influenced by properties of original IMC layer.

关键词： Refill friction stir spot welding Al alloy Steel Coated materials Joining mechanism

Multilinear Singular and Fractional Integrals

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Acta Mathematica Sinica,English Series 2006年第2期22卷 347-356页

作者： Yong ding Shan zhen lU Kz YABUTA School of Matematical Sciences Beijing Normal Unioversity School of Science and Technology Kwansei Gakuin University

In this paper, we treat a class of non-standard commutators with higher order remainders in the lipschitz spaces and give （l^v, l^q）, （H^p, l^q） boundedness and the boundedness in the Triebel- lizorkin spaces. Our... 详细信息

关键词： commutators multilinear operators singular and fractional integrals lp spaces Hardy

Preliminary Study on Corrosion Behaviour of Carbon Steel in Oil–Water Two-Phase Fluids

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Journal of Materials Science & Technology 2015年第12期31卷 1274-1281页

作者： z.Y.Hu D.l.Duan S.H.Hou X.J.ding S.li Institute of Metal Research Chinese Academy of Sciences

The corrosion behavior of type 1045（AISI） carbon steel（CS） in oil-water fluids was investigated by considering the surface wetting state as the breakthrough *** surface water wetting percentage（SWWP）and corrosion weight loss of CS in different oil-water fluids were *** morphology and composition of the corrosion films were detected via scanning electron microscopy,electron-probe facescanning technology and Fourier-transform infrared *** results indicated that the corrosion weight loss of CS in the oil-water fluids corresponded with SWWP and that the corrosion process was influenced by the participation of oil.

关键词： Carbon steel Corrosion behavior Wetting Fluid flow Fourier transform infrared(FTIR) spectroscopy

Electrochemical studies of Meldola blue-modified bilayer lipid membranes

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Chinese Science Bulletin 1997年第3期42卷 203-207页

作者： ding, l Wang, EK CHINESE ACAD SCI CHANGCHUN INST APPL CHEMELECTROANALYT CHEM LABCHANGCHUN 130022PEOPLES R CHINA

BIlAYER lipid membranes (BlM) have been extensively regarded as a basic structure that forms the matrix of biological membranes. The properties of BlM may be altered by incorporation and modification and can be employed to study many membrane processes. Especially biosensors and bi-molecular electronic devices made by BlM have a wide application. Many kinds of organic dyes are known as biological stains and often used in biology, physiology, pharmacology and medicine. In general, coloring and staining processes involve adsorp-

关键词： Meldola blue bilayer lipid membranes (BlM) electrochemistry.