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Chinese Journal of Polymer Science 2020年第11期38卷 1230-1238,I0008页

作者： Na Li Xing-Ke Zhang Jun-Rong Yu Yan Wang Jing Zhu zu-ming hu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China

The demand for high thermal stability and high strength agents is growing steadily as a result of their increasing application in advanced materials.A series of sulfonated poly(m-phenyleneisophthalamide)(SPMIA)copolymers with superior thermal stability and good mechanical properties have been prepared via low temperature polycondensation *** the structures of 5PMA copolymers with different content quantities of 2,4-diaminobenzenesulfonic acid(2,4-DABSA)were confimed by Fourier transform infrared(FTiR).Besides,their superior thermal properties were systematically investigated by differential canning calorimetry DSC),thermalgravimetreic analysis(TGA),and dynamic mechanical analysis(DMA).SPMA fbers were obtained by wet spinning using the resultant SPMIAsolutions.n addition,the obtained SPMIA fibers were proved to combine enhanced mechanical properties and unprecedented ***,the SPMlA iber with great mechanical property,thermal stability,and dyeability shows great potential in easily dyeing high-performance protective fibers.

关键词： Sulfonated polyim-phenyleneisophthalamide) Copolymer Sulfonic acid group High-Performance fiber Eaily dyeable fiber

Synthesis and Characterization of Easily Colored Meta-aramid Copolymer Containing Ether Bonds

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Chinese Journal of Polymer Science 2019年第3期37卷 227-234页

This work described the preparation of easily colored meta-aramid(PMIA) copolymers from m-phenylenediamine(MPD),isophthaloyl dichloride(IPC), and 3,4′-oxydianiline(3,4′-ODA) via solution polycondensation in N,N-dimethylacetamide(DMAc). The novel co-PMIAs were obtained in relatively high inherent viscosities ranging from 1.32 dL/g to 2.53 dL/g, which could be easily cast into flexible films with high transparence or spun into fibers. All the newly synthesized copolymers possessed excellent thermal stabilities even better than that of commercial PMIA, with 5% weight loss temperatures higher than 430 °C in nitrogen measured by TGA and glass transition temperature of 267–277 °C measured by DSC. The cast films exhibited good mechanical properties with a tensile strength up to107 MPa and a tensile modulus up to 2.2 GPa. The resultant PMIAs also showed good solubility and better dye ability for cationic dyes.

关键词： Copolymerized meta-aramid Solution polycondensation Dyeability

Tailoring the Properties of Diels-Alder Reaction Crosslinked High-performance Thermosets by Different Bismaleimides

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Chinese Journal of Polymer Science 2020年第3期38卷 268-277,I0007页

作者： Kai-Ju Luo Li-Bo huang Yan Wang Jun-Rong Yu Jing Zhu zu-ming hu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Material Science and EngineeringDonghua University

A series of Diels-Alder reaction cross-linked thermosets with recyclability and healability were prepared from furan-containing aromatic polyamide and bismaleimides with different chemical *** structures of synthesized bismaleimides were confirmed by 1 H nuclear magnetic resonance(1 H-NMR)spectroscopy;their reversible cross-linking with the furanic polyamide was further detected by 1 H-NMR technique and sol-gel transition *** dynamic mechanical analysis and tensile test revealed the variable thermal and mechanical properties of thermosets cross-linked by different bismaleimides and with different molar ratios of maleimide group to furan group(Ima/fur).The tensile test also demonstrated that the better recyclability and solvent-assisted healability of thermosets cross-linked could be achieved by more flexible *** work is expected to provide valuable information for design of recyclable and healable high-performance thermosets with desired properties.

关键词： Recyclability Reparability Thermosets Diels-Alder reaction

Preparation of Hydrophilic UHMWPE Hollow Fiber Membranes by Chemically Bounding Silica Nanoparticles

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Chinese Journal of Polymer Science 2021年第2期39卷 189-200,I0006页

作者： Lian-Lian Fan Jia-You Quan Hao Zhang Jun-Rong Yu zu-ming hu Yan Wang Shanghai Collaborative Innovation Center for High Performance Fiber Composites College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Sinochem International Corporation Shanghai 200126China

In this work, ultra-high molecular weight polyethylene (UHMWPE) microfiltration hollow fiber membranes prepared via the thermally induced phase separation (TIPS) method were modified by chemically bounding hydrophilic silica (SiO2) nanoparticles onto the surface to improve anti-fouling performance. A range of testing techniques including attenuated total reflection Flourier transformed infrared spectroscopy(ATR-FTIR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), water contact angle, mechanical test,filtration and anti-fouling performance were carried out to discuss the influence of different modification conditions on the properties of the membranes. The prepared hollow fiber membranes display the significantly excellent performance when the vinyl trimethoxy silane (VTMS) concentration was 13%, the pH value of the hydrolyzate was 4 and the hydrolysis reaction time was 6 h. In particular, the hydrophilicity of modified membranes was improved effectively, resulting in the enhancement of membrane anti-fouling properties. The results of this work can be consulted for improving the anti-fouling performance of the UHMWPE microfiltration hollow fiber membrane applied in the field of water purification.

关键词： Hollow fiber membrane Hydrophilic Anti-fouling Silica(SiO2)nanoparticles Water purification

Ferrite features in simulated transition zone of EH36 shipbuilding steel submerged arc welded by CaF_(2)-SiO_(2)-MnO fluxes

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Journal of Iron and Steel Research International 2024年第4期31卷 790-796页

作者： ming Zhong Dong hu Da-ming Guo Somnath Basu Cong Wang Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Department of Metallurgical Engineering and Materials Science Indian Institute of Technology BombayMumbai 400076MaharashtraIndia

Ferrite features in the simulated transition zone welded with CaF_(2)-SiO_(2)-MnO fluxes containing various MnO contents have been *** laser scanning microscopy has been applied to simulate the thermal cycling of the transition zone and the phase transformations during cooling have been in-situ *** has been found that the appearance temperature for ferrite side plate decreases with increasing Mn content in the weld metals caused by MnO content ***,growth rates for both ferrite side plate and acicular ferrite are significantly enhanced with a higher Mn content of weld ***,from the statistical fractions of salient microstructures,for all samples,the acicular ferrite,grain boundary ferrite,and polygonal ferrite take over more than 90%.It has also been demonstrated that with the increase in Mn content,the ferrite side plate fraction increases slightly from 5%to 10%and the acicular ferrite fraction shows a tendency of first increasing and then decreasing,which experiences the maximum with the flux containing 30 wt.%*** phenomenon is believed to be controlled by the O and Mn contents in weld metals synergistically.

关键词： Submerged arc welding Transition zone Phase transformation Microstructure

Reaction behavior of MgO refractory with high-Mn and high-Al steel

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Journal of Iron and Steel Research International 2024年第6期31卷 1389-1398页

作者： Ling-zhong Kong Lin zu Jie Yang Xi-min Zang Xin Yang ming Kang School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

To understand the mechanism of the interfacial reaction between high-Mn and high-Al steel and MgO refractory,a series of laboratory experiments as well as thermodynamic calculations were *** effects of Mn and Al contents in the steel and the reaction time on the interfacial reaction were *** was observed that the erosion of the MgO refractory is caused by the reaction of Al and Mn in the steel with MgO in the refractory,which would lead to the formation of(Mn,Mg)O·Al_(2)O_(3) spinel and(Mn,Mg)O solid *** formation mechanism of the spinel and solid solution is as *** Al in the steel firstly reacts with MgO in the refractory to generate MgO·Al_(2)O_(3) spinel,and then,the spinel reacts with Mn in the steel to form(Mn,Mg)O·Al_(2)O_(3) ***,the MnO in the spinel reacts with the MgO in the inner refractory to form(Mn,Mg)O solid *** addition,only(Mn,Mg)O·Al_(2)O_(3) spinel is present in the interfacial reaction layer of the refractory when the Al content in the steel is sufficient.

关键词： High-Mn high-Al steel MgO refractory Reaction behavior Spinel

Grain size effect on the assembly quality of micro-scaled barrel formed by microforming

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Advances in Manufacturing 2024年第1期12卷 19-32页

作者： Dien hu Jieyichen Fang Feng Zeng ming-Wang Fu Department of Mechanical Engineering Research Institute of Advanced ManufacturingThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongPeople’s Republic of China Xiamen Yulong Machinery Co.Ltd. Xiamen361023FujianPeople’s Republic of China

In this research,a method employing micro-extrusion was designed to produce the micro-scaled barrel-shaped parts with complex geometrical features to study the feasibility of the proposed microforming method and its grain size effect on the formability of the complicated internal features in terms of deformation behavior,material evolution,accuracy of dimensions and final components *** results reveal that the deformation behavior is highly affected by grain size and becomes unpredictable with increased grain *** addition,assembly parameters including feature dimension,tolerance and coaxiality also vary with grain size,and the variation of grain size needs to be accommodated by different assembly types,viz.,clearance fit or transition *** the microstructural evolution aspect,it was identified there were two dead zones and four shear bands,and the formation of these deformation zones was barely affected by the variation in grain *** bulges,cracks,and fracture induced voids were observed on the surface of the final components,tailoring the microstructure of the working material with finer grains could significantly avoid these *** study advances the understanding of forming microparts by extrusion processes and provides guidance for microforming of similar microparts.

关键词： Microformed part Size effect Extrusion Microstructural evolution Dimensions Assembly accuracy

Assessment of Wet Season Precipitation in the Central United States by the Regional Climate Simulation of the WRFG Member in NARCCAP and Its Relationship with Large-Scale Circulation Biases

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Advances in Atmospheric Sciences 2024年第4期41卷 619-638页

作者： Yating ZHAO ming XUE Jing JIANG Xiao-ming hu Anning huANG School of Atmospheric Sciences Nanjing UniversityNanjing 210023China Center for Analysis and Prediction of Storms and School of Meteorology The University of OklahomaNorman 73072U.S.A

Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional ***,we assess the performance and discuss possible causes of biases in a WRF-based RCM with a grid spacing of 50 km,named WRFG,from the North American Regional Climate Change Assessment Program(NARCCAP)in simulating wet season precipitation over the Central United States for a period when observational data are *** RCM reproduces key features of the precipitation distribution characteristics during late spring to early summer,although it tends to underestimate the magnitude of *** dry bias is partially due to the model’s lack of skill in simulating nocturnal precipitation related to the lack of eastward propagating convective systems in the *** in reproducing large-scale circulation and environmental conditions is another contributing *** too weak simulated pressure gradient between the Rocky Mountains and the Gulf of Mexico results in weaker southerly winds in between,leading to a reduction of warm moist air transport from the Gulf to the Central Great *** simulated low-level horizontal convergence fields are less favorable for upward motion than in the NARR and hence,for the development of moist convection as ***,a careful examination of an RCM’s deficiencies and the identification of the source of errors are important when using the RCM to project precipitation changes in future climate scenarios.

关键词： NARCCAP Central United States precipitation low-level jet large-scale environment diurnal variation

A NONLOCAL KRONECKER-BASIS-REPRESENTATION METHOD FOR LOW-DOSE CT SINOGRAM RECOVERY

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Journal of Computational Mathematics 2024年第4期42卷 1080-1108页

作者： Jian Lu huaxuan hu Yuru Zou Zhaosong Lu Xiaoxia Liu Keke zu Lin Li Shenzhen Key Laboratory of Advanced Machine Learning and Applications College of Mathematics and StatisticsShenzhen UniversityShenzhen 518060China National Center for Applied Mathematics Shenzhen(NCAMS) Shenzhen 518055China Department of Industrial and Systems Engineering University of Minnesota Twin CitiesMinneapolisMN55455USA Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong Kong SARChina School of Electronic Engineering Xidian UniversityXi'an 710071China

Low-dose computed tomography(LDCT)contains the mixed noise of Poisson and Gaus-sian,which makes the image reconstruction a challenging *** order to describe the statistical characteristics of the mixed noise,we adopt the sinogram preprocessing as a stan-dard maximum a posteriori(MAP).Based on the fact that the sinogram of LDCT has non-local self-similarity property,it exhibits low-rank *** conventional way of solving the low-rank problem is implemented in matrix forms,and ignores the correlations among similar patch *** avoid this issue,we make use of a nonlocal Kronecker-Basis-Representation(KBR)method to depict the low-rank problem.A new denoising model,which consists of the sinogram preprocessing for data fidelity and the nonlocal KBR term,is developed in this *** proposed denoising model can better illustrate the generative mechanism of the mixed noise and the prior knowledge of the ***-merical results show that the proposed denoising model outperforms the state-of-the-art algorithms in terms of peak-signal-to-noise ratio(PSNR),feature similarity(FSIM),and normalized mean square error(NMSE).

关键词： Low-dose computed tomography Kronecker-basis-representation Low-rank imation.Noise-generating-mechanism

A Quasi-Linear Relationship between Planetary Outgoing Longwave Radiation and Surface Temperature in a Radiative-Convective-Transportive Climate Model of a Gray Atmosphere

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Advances in Atmospheric Sciences 2024年第1期41卷 8-18页

作者： Jie SUN Michael SECOR ming CAI Xiaoming hu Department of Earth Oceanand Atmospheric ScienceFlorida State UniversityTallahasseeFlorida 32304USA School of Atmospheric Sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Zhuhai 519082China

In this study,we put forward a radiative-convective-transportive energy balance model of a gray atmosphere to examine individual roles of the greenhouse effect of water vapor,vertical convection,and atmospheric poleward energy transport as well as their combined effects for a quasi-linear relationship between the outgoing longwave radiation(OLR)and surface temperature(T_(S)).The greenhouse effect of water vapor enhances the meridional gradient of surface temperature,thereby directly contributing to a quasi-linear OLR-T_(S) *** atmospheric poleward energy transport decreases the meridional gradient of surface *** a result of the poleward energy transport,tropical(high-latitude)atmosphere-surface columns emit less(more)OLR than the solar energy input at their respective locations,causing a substantial reduction of the meridional gradient of the *** combined effect of reducing the meridional gradients of both OLR and surface temperature by the poleward energy transport also contributes to the quasi-linear OLR-T_(S) *** convective energy transport reduces the meridional gradient of surface temperature without affecting the meridional gradient of OLR,thereby suppressing part of the reduction to the increasing rate of OLR with surface temperature by the greenhouse effect of water vapor and poleward energy *** of the nature of the energy balance in the climate system,such a quasi-linear relationship is also a good approximation for the relationship between the annual-mean net downward solar energy flux at the top of the atmosphere and surface temperature.

关键词： outgoing longwave radiation greenhouse effect poleward energy transport