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Chinese Chemical Letters 2012年第11期23卷 1307-1310页

作者： An Qi Ju shan yi guang Hong Yao Xu College of Materials Science and Engineering&State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Donghua UniversityShanghai 201620China College of Chemistry&Chemical Engineering Donghua UniversityShanghai 201620China

A novel bifunctional comonomer 3-ammoniumcarboxylate-butenoic acid-methyl ester （ACBM） was synthesized tor preparing poly[acrylonitrile-co-（3-ammoniumcarboxylate-butenoic acid-methyl ester）] [P（AN-co-ACBM）] copolymer as a carbon fiber precursor. Differential scanning calorimetry results show that the P（AN-co-ACBM） exhibits a significantly improved stabilization performance compared with polyacrylonitrile （PAN）, such as lower cyclization temperature and smaller rate of heat release, which is mainly attributed to the initiation of ACBM through an ionic cyclization mechanism. Simultaneously, the rheological analysis shows that P（AN-co-ACBM） possesses better spinnabilitv than PAN.

关键词： Polyacrylonitrile Carbon fiber Thermal analysis DSC Polymerization

A versatile nanobuilding precursor for the effective architecture of well-defined organic/inorganic hybrid via click chemistry

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Chinese Chemical Letters 2012年第9期23卷 1095-1098页

作者： Ya Kun Zhu shan yi guang Hong Yao Xu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials&College of Material Science and Engineering Donghua UniversityChina Shanghai 201620 College of Chemistry Chemical Engineering and BiotechnologyDonghua UniversityChina Shanghai 201620

A novel octazido substituted nanobuilding precursor, octakis[dimethy（p-azidomethylene）siloxyl]octasilsesquioxane （ODA）, was prepared by the conventional diazo-transfer reaction of octalds[dimethy（p-chloromethylene）silyl]octasilsesquioxane （ODC） with NAN3, and its structure was characterized by FT-IR, 1H, a3C, 29Si NMR and MALDI-TOF MS, respectively. The structural rearrangement of POSS core in the synthesis strategy of ODA developed in this work was effectively prohibited in comparison with traditionary azidization process. The resultant ODA was not only soluble in common solvents such as CHC13, THF, toluene, DMF and DMSO, but also could effectively serve as a versatile nanobuilding precursor for the architecture of well-defined organic- inorganic hybrids via click chemistry.

关键词： Azides POSS Nanoparticles Structural Click chemistry

Synthesis and characterization of poly(methyl methacrylate-co-polyhedral oligomeric silsesquioxane)hybrid nanocomposites

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Chinese Chemical Letters 2007年第8期18卷 960-962页

作者： Ben Hong Yang Hong Yao Xu Cun Li shan yi guang School of Chemistry and Chemical Engineering Anhui University Hefei 230039 China College of Material Science and Engineering ＆ State Key Laboratory of Chemical Fibers and Polymeric Materials Donghua University Shanghai 200051 China Department of Chemical and Material Engineering Hefei University Hefei 230022 China

A novel poly（methyl methacrylate-co-polyhedral oligomeric silsesquioxane） hybrid nanocomposite was synthesized by free radical polymerization and characterized by 1H NMR, 29Si NMR, and TGA technologies. Compared wit... 详细信息

关键词： Poly(methyl methacrylate) Polyhedral silsesquioxane Nanoeomposite

Preparation and near-infrared optical limiting property of fluorene-containing functional polyacetylene

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Chinese Chemical Letters 2011年第10期22卷 1257-1260页

作者： Nai Bo Lin Yan Feng shan yi guang Hong Yao Xu College of Material Science and Engineering ＆ College of Chemistry and Chemical Engineering Donghua University Shanghai 201620 China College of Chemistry and Chemical Engineering Anhui University Hefei 230039 China

A novel functional polyacetylene containing fluorene group as a pendant,poly（2-（p-methylstyrene）-7-acetylene-9,9-dioctyl-fluorene）, was synthesized in moderate yield by[Rh（nbd）Cl]_2-Et_3N *** structures and properties of monomer and polymer were characterized and evaluated with FTIR,NMR,UV-vis,GPC and Z-scan,*** results show that the incorporation of fluorene into polyacetylene has endowed the resultant polymer with well optical limiting properties for laser at wavelength 780 nm based on two-photon absorption mechanism.

关键词： Substituted polyacetylene Fluorene Nonlinear optics Two-photon absorption

Acetylene/argon mixture plasma to build ultrathin carbon bridge of CF_(x)/C/MnO_(2) for high-rate lithium primary battery

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Rare Metals 2024年第6期43卷 2574-2584页

作者： Da-Wei Zou Xing-guang Fu Gao-Bang Chen yi-Fan Liu Bao-shan Wu Xian Jian School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 31300lChina

Forming an ultrathin conducting layer on a fluorinated carbon(CFx)surface for reducing severe electrochemical polarization in lithium/fluorinated carbon primary batteries(Li/CF_(x))remains a considerable challenge for achieving batteries with excellent rate ***,CFxwas modified by using acetylene/argon mixture plasma combined with MnO_(2)*** CF_(x)/C/MnO_(2)composite effectively reduced the voltage hysteresis and improved the electrochemical performance of Li/CF_(x).The excellent rate performance of CF_(x)/C/MnO_(2)was due to the high electrochemical activity provided by the atomicscale conductive carbon layer and ultrafine MnO_(2)*** with pristine CF_(x),the charge transfer resistance of the optimized CF_(x)/C/MnO_(2)decreased from 218.5 to 48.2Ω,the discharge rate increased from 2C to 10C,and the power density increased from 3.11 to 13.44 kW·g^(-1),The intrinsic reason for the enhanced rate performance was attributed to the fact that the ultrathin carbon layer acted as a conductive bridge to reduce the voltage hysteresis at the initial stage of the Li/CF_(x)discharge,and the high electrochemical activity of the ultrafine MnO_(2)particles provided a faster lithium-ion diffusion rate.

关键词： C_(2)H_(2)/Ar plasma Fluorinated carbon Lithium primary battery MnO_(2)

Porous Ti_(3)C_(2)T_(x) MXene nanosheets sandwiched between polyimide fiber mats for electromagnetic interference shielding

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Nano Research 2024年第3期17卷 2070-2078页

作者： Wenhao Liang Juntao Wu shan Zhang Pei-Yan Zhao yi Cong Yongqiang Guo guang-Sheng Wang Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China

With the rapid development of wireless communication technology and electronic devices,the issue of electromagnetic interference(EMI)is becoming increasingly *** a new and flexible electromagnetic interference shielding material has become a challenging ***,a sandwich-structured EMI shielding composite film was prepared using electrospinning and vacuum filtration *** this process,a porous MXene was synthesized through a reaction with cobalt acetate and served as the intermediate layer in the composite film to shield electromagnetic *** electrospun polyimide(PI)fibers were used as the top and bottom layers of the composite film,which can protect the porous MXene from *** lightweight and flexible composite film integrates electromagnetic interference shielding and thermal insulation capabilities,showing excellent comprehensive *** composite film achieves an EMI shielding effectiveness of 48.8 dB in X-band(8.2–12.4 GHz),and absolute shielding effectiveness of the composite film reached a satisfying 4142.43(dB·cm^(2))/*** to the design of a multi-layer porous structure,the density of the composite film is 0.65 g/***,the thermal conductivity of the film is 0.042 W/(m·K)due to the clamping of electrospun PI fibers,showing excellent thermal insulation ***,the composite film exhibits excellent high and low-temperature *** summary,this work provides a feasible strategy for preparing a lightweight polymer-based EMI shielding film.

关键词： porous MXene polyimide electromagnetic interference shielding thermal insulation

Essential Players in Cooperative Games with Graph Communication Structure

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Journal of the Operations Research Society of China 2024年第1期12卷 93-108页

作者： guang Zhang Jing-yi Ge Business School University of Shanghai for Science and TechnologyShanghai200093China

A class of cooperative games with graph communication structure is studied in this paper by considering some important players,namely essential *** the assumption that only connected coalitions containing essential players are able to cooperate and obtain their worths,the class of graph games with essential players is proposed as well as an allocation *** proposed value follows the spirit of the Myerson value defined by applying the Shapley value on a modified *** properties,feasible component efficiency,the inessential component property,and fairness,are provided to fully characterize this value,where feasible component efficiency and fairness follows the same ideas of component efficiency and fairness for classical graph games,and the inessential component property says that the total payoffs of the players in a non-feasible component is ***,some computational aspects of the proposed value and comparisons with disjunctive permission value for games with permission structure are also studied,respectively.

关键词： Cooperative game Graph structure Essential player Myerson value Computation Permission structure

Differentially private SGD with random features

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 1-23页

作者： WANG yi-guang GUO Zheng-chu Polytechnic Institute of Zhejiang University Zhejiang UniversityHangzhou 310015China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China

In the realm of large-scale machine learning,it is crucial to explore methods for reducing computational complexity and memory demands while maintaining generalization ***,since the collected data may contain some sensitive information,it is also of great significance to study privacy-preserving machine learning *** paper focuses on the performance of the differentially private stochastic gradient descent(SGD)algorithm based on random *** begin,the algorithm maps the original data into a lowdimensional space,thereby avoiding the traditional kernel method for large-scale data storage ***,the algorithm iteratively optimizes parameters using the stochastic gradient descent ***,the output perturbation mechanism is employed to introduce random noise,ensuring algorithmic *** prove that the proposed algorithm satisfies the differential privacy while achieving fast convergence rates under some mild conditions.

关键词： learning theory differential privacy stochastic gradient descent random features reproducing kernel Hilbert spaces

Enhancing Low-Frequency Microwave Absorption Through Structural Polarization Modulation of MXenes

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Nano-Micro Letters 2024年第10期16卷 435-452页

作者： Bo shan Yang Wang Xinyi Ji yi Huang College of Light Industry Science and Engineering State Key Laboratory of Biobased Fiber Manufacturing TechnologyTianjin University of Science and TechnologyTianjin 300457People's Republic of China National Institute for Advanced Materials Tianjin Key Laboratory of Metal and Molecule Based Material ChemistryKey Laboratory of Functional Polymer MaterialsCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)School of Materials Science and EngineeringNankai UniversityTianjin 300350People's Republic of China

Two-dimensional carbon-based materials have shown promising electromagnetic wave absorption capabilities in mid-and high-frequency ranges,but face challenges in low-frequency absorption due to limited control over polarization response mecha-nisms and ambiguous resonance *** this study,we pro-pose a novel approach to enhance absorption efficiency in aligned three-dimensional(3D)MXene/CNF(cellulose nanofibers)cavities by modifying polarization properties and manipulating resonance response in the 3D MXene *** controlled polarization mechanism results in a significant shift of the main absorption region from the X-band to the S-band,leading to a remarkable reflection loss value of-47.9 dB in the low-frequency ***,our findings revealed the importance of the oriented electromagnetic coupling in influencing electromagnetic response and microwave absorption *** present study inspired us to develop a generic strategy for low-frequency tuned absorption in the absence of magnetic element participation,while orientation-induced polarization and the derived magnetic resonance coupling are the key controlling factors of the method.

关键词： Hierarchical structure MXene Microwave absorption Low-frequency

Synthesis and optical limiting in copolymers of C_(60) and 1-phenyl-1-butyne

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Chinese Chemical Letters 2000年第1期11卷 21-22页

作者： Hong Yao XU shan yi guang Ben Zhong TANG (Department of Chemistry, Anhui University, Hefei 230039 Department of Chemistry, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong) Anhui Univ Dept Chem Hefei 230039 Peoples R China Hong Kong Univ Sci & Technol Dept Chem Kowloon Peoples R China

While WC_16-Ph_4Sn is a poor catalyst for the polymerization of l-phenyl-butyne (PB) at room temperature, it effectively polymerizes PB in the presence of C_(60), giving high molecular weight polymers in high yields. The polymer is soluble in THF and chloroform and spectroscopic analysis reveals that Coo has copolymerized with PB. Thus, C_(60) plays dual roles of comonomer and cocatalyst in the acetylene polymerization. The copolymers strongly attenuate 532-nm laser pulses, whose limiting performance is superior to that of parent C_(60)

关键词： C_(60) polyacetylene fullerene polymer.