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Methyl Groups Pendant on Triphenylmethane Toward Modulating Thermal Stability and Dielectric Properties of the Crosslinkable Fluorinated Polyimide Films with High Transparency

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Chinese Journal of Polymer Science 2025年第2期43卷 316-327页

作者： wen Yang Liang Yuan Kai Gong Ruo-Han Zhang Lan Lei Hui Li School of Chemistry and Chemical Engineering Shandong Key Laboratory of Fluorine Chemistry and Chemical Engineering MaterialsUniversity of JinanJinan250022China School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional MaterialsTianjin UniversityTianjin300350China

It is urgent to develop high-performance polyimide(PI)films that simultaneously exhibit high transparency,exceptional thermal stability,mechanical robustness,and low dielectric to fulfil the requirements of flexible display ***,a series of fluorinated polyimide films(FPIs)were fabricated by the condensation of 5,5′-(perfluoropropane-2,2-diyl)bis(isobenzofuran-1,3-dione)(6FDA)and the fluorinated triphenylmethane diamine monomer(EDA,MEDA and DMEDA)with heat-crosslinkable tetrafluorostyrene side groups,which was incorporated by different numbers of methyl groups pendant in the ortho position of amino ***,the FPI films underwent heating to produce crosslinking FPIs(C-FPIs)through the self-crosslinking of double bonds in the *** transparency,solvent resistance,thermal stability,mechanical robustness and dielectric properties of FPI and C-FPI films can be tuned by the number of methyl groups and crosslinking,which were deeply investigated by virtue of molecular dynamics(MD)simulations and density functional theory(DFT).As a result,all the films exhibited exceptional optically colorless and transparent,with transmittance in the visible region of 450-700 nm exceeding 79.9%,and the cut-off wavelengths(λ_(off))were nearly 350 *** thermal decomposition temperatures at 5% weight loss(T_(d5%))for all samples exceeded 504℃.These films exhibited a wide range of tunable tensile strength(46.5-75.1 MPa).Significantly,they showed exceptional dielectric properties with the dielectric constant of 2.3-2.5 at full frequency(10^(7)-20 Hz).This study not only highlights the relationship between the polymer molecular structure and properties,but offer insights for balancing optical transparency,heat resistance and low dielectric constant in PI films.

关键词： Crosslinkable fluorinated polyimide Methyl group Triphenylmethane Transparency Thermal stability Low dielectric constant

Synthesis of ordered mesoporous crystalline boron phosphate scaffold with double diamond surface structure

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Science China Chemistry 2025年第2期68卷 590-600页

作者： Chao Wang wen-Duo Lu Jiao Wang Shunai Che An-Hui Lu Lu Han School of Chemical Science and Engineering Tongji UniversityShanghai 200092China State Key Laboratory of Fine Chemicals Liaoning Key Laboratory for Catalytic Conversion of Carbon ResourcesSchool of Chemical EngineeringDalian University of TechnologyDalian 116024China School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesState Key Laboratory of Metal Matrix CompositesShanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai 200240China

Ordered mesoporous materials have received great attention due to their well-defined pore structures and potential applications in catalysis,adsorption,separation,drug delivery,*** various compositions of mesoporous solids have been successfully prepared,the preparation of crystalline non-metallic oxyacid salts with ordered mesoporosity remains a major ***,we report the synthesis of a mesoporous solid acid crystalline boron phosphate(BPO_(4))catalyst with a bicontinuous shifted double diamond(SDD)hyperbolic surface *** BPO_(4) scaffold was obtained by synergistic selfassembly in a mixed solvent of water and tetrahydrofuran using the diblock copolymer poly(ethylene oxide)-block-polystyrene as template and phosphoric acid and orthoboric acid as inorganic *** structure consists of two sets of diamond networks adjacent to each other with a mesostructural scale tetragonal symmetry(space group I4_(1)/amd)with unit cell parameters of a=80 nm and c=113 nm,which affords the scaffold a specific surface area of 44 m^(2)/*** a solid acid catalytic material,the SDD BPO_(4) scaffold exhibited excellent catalytic activity at room temperature with a conversion of furfural to 2-(dimethoxymethyl)furan over 70%and can be reused after recovery without serious loss of *** the propane oxidative dehydrogenation reaction,SDD BPO_(4) demonstrated high olefin productivity and selectivity while maintaining high reaction *** study provides ideas for the preparation of ordered mesoporous crystalline catalytic materials and demonstrates their potential for practical applications.

关键词： boron phosphate mesoporous material self-assembly block copolymer catalyst

Worldvolume fermions as baryons in holographic quantum chromodynamics with instantons

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Communications in Theoretical Physics 2025年第1期77卷 106-121页

作者： Si-wen Li Hao-qian Li Yi-peng Zhang Department of Physics School of ScienceDalian Maritime UniversityDalian 116026China

In this study,we investigated worldvolume fermions on the flavor brane in the D0-D4/D8 model,which is holographically equivalent to four-dimensional quantum chromodynamics with instantons or equivalently with a theta *** action involving the worldvolume fermions was obtained by the T-duality rules in string theory,and we accordingly derived their effective five-dimensional and canonical four-dimensional forms by using the systematic dimensional reduction and decomposition of the ***,we used the AdS/CFT dictionary to evaluate the two-point correlation function as the spectral function for the worldvolume fermions and interpreted the fermions as baryons by analyzing their quantum number with the baryon vertex in *** this sense,the interacted action involving the worldvolume fermions and gauge field on the flavor brane was finally derived in holography,which describes the various interactions of mesons and baryons with instantons in the large-N ***,this study provides a holographic picture to describe baryons and their interactions based on string theory,particularly in the presence of instantons or a theta angle.

关键词： gauge-gravity duality AdS/CFT holographic QCD

Broadband and perfect terahertz absorber based on multilayer metamaterial with cross-ring patterned structures

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Optoelectronics Letters 2025年第1期21卷 1-6页

作者： wen Jin LIU Zhanzhi WU Zhengwei PAN Yu ZHANG Ying School of Science Xian Shiyou UniversityXi'an 710065China Shaanxi Key Laboratory of Measurement and Control Technology for Oil and Gas Wells Xi'an 710065China

Broadband and perfect terahertz absorber based on multilayer metamaterial using cross-ring patterned structures is proposed and *** structure of the absorber is double absorption layers consisting of a chromium cross ring and eight isosceles right *** unique structure of the double absorbing layers excites the electric dipole multimode resonance,giving rise to high absorption ***,the influence of construal parameters on absorber behavior is also *** numerical results show that the absorption achieves over 90%ranging from 2.45 THz to 6.25 THz and 99%absorption in the range of 3.7—5.3 *** realization of broadband and perfect absorber is described using the impedance matching *** is obviously found that the absorber is insensitive to the high angle of incidence for both transverse electric(TE)and transverse magnetic(TM)*** with the former reports,this absorber has remarkable improved absorption efficiency and smaller *** terahertz absorber may be found applications in the fields of energy capture and thermal detection.

关键词： polarization absorber perfect

A cross-sectional study of the association between dietary inflammatory index and glaucoma prevalence in a US population

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International Journal of Ophthalmology(English edition) 2025年第1期18卷 139-145页

作者： wen-Li Chen Li-Xia Zhang Department of Ophthalmology Zhejiang Chinese Medical University Affiliated Wenzhou Hospital of Integrated Traditional Chinese and Western MedicineWenzhou 325000Zhejiang ProvinceChina Eye Hospital China Academy of Chinese Medical SciencesBeijing 100040China

AIM:To assess the relationship between dietary inflammatory index(DII)and prevalence of glaucoma among individuals aged 40y and above in the United ***:Participants were drawn from 2 cycles of the National Health and Nutrition Examination Survey(NHANES,2005-2008)for a cross-sectional *** was calculated from 24-hour dietary recall questionnaire conducted by experienced researchers and data analyzed in R according to the NHANES user guide,“Stratified Multi-stage Probability Sampling”.The relationship between DII and glaucoma was evaluated by multi-factor logistic regression analysis and the existence of a non-linear association examined by restricted cubic spline(RCS)***:A total of 5359 subjects were included and the cross-sectional analysis weighted to represent the US population of 109 *** was elevated in glaucoma patients(P<0.001)and smoking and alcohol use contributed to significant differences(P<0.001).DII correlated negatively with Healthy Eating Index(HEI)-2015(Spearman rank correlation coefficient,r=-0.49).RCS analysis showed a linear relationship between DII and glaucoma risk(P of non-linear relationship=0.575).CONCLUSION:An increased DII is strongly associated with high risk of glaucoma and diet-induced inflammation should be controlled to delay glaucoma progression.

关键词： glaucoma risk factors dietar y inflammatory index National Health and Nutrition Examination Survey restricted cubic spline regression cross-sectional study

Achieving further refinement of grain structure and improvement of mechanical properties in Al-12Si-4Cu-2Ni-1Mg alloy by Al-Ti-C-B master alloy addition and deep cryogenic treatment

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China Foundry 2025年第1期22卷 75-82页

作者： Lin-fei Xia wen-bo Li Zuo-shan Wei Yu-ying Wu Xiang-fa Liu China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China Shandong Key Laboratory of Advanced Aluminum Materials and Technology Binzhou Institute of TechnologyBinzhou 256600ShandongChina

Near-eutectic Al-Si alloys are widely used in automotive manufacturing due to their superior wear resistance and high temperature *** of high Si content,the grain refinement of near-eutectic Al-Si alloy has been a problem for many *** this study,the effect of deep cryogenic treatment(DCT)on the microstructure and mechanical properties of Al-12Si-4Cu-2Ni-Mg alloy with addition of Al-Ti-C-B master alloy was fully *** show that the average grain size of the alloy is greatly reduced from 0.92 mm to 0.50 mm,and the eutectic Si and Al7Cu4Ni precipitates are spheroidized and refined in Al-12Si-4Cu-2Ni-Mg after DCT for 24 h and aging *** these changes of microstructures result in a significant increment of about 22.5%in elongation and a slight enhancement of about 6.8%in tensile ***,the refinement of microstructure also significantly improves the fatigue life of the alloy.

关键词： deep cryogenic treatment near-eutectic Al-Si master alloy microstructure mechanical properties

Impact of coking plant to heavy metal characteristics in groundwater of surrounding areas:Spatial distribution,source apportionment and risk assessments

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Journal of Environmental Sciences 2025年第3期149卷 688-698页

作者： Congqing Wang Wanjun Wang ChaoWang Shixing Ren Yingjun Wu Meicheng wen Guiying Li Taicheng An Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory Environmental Catalysis and Pollution Control Key Laboratory of City Cluster Environmental Safety and Green developmentSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Coking industry is a potential source of heavy metals(HMs)***,its impacts to the groundwater of surrounding residential areas have not been well *** study investigated the pollution characteristics and health risks of HMs in groundwater nearby a typical coking *** HMs including Fe,Zn,Mo,As,Cu,Ni,Cr,Pb and Cd were *** average concentration of total HMswas higher in the nearby area(244.27μg/L)than that of remote area away the coking plant(89.15μg/L).The spatial distribution of pollution indices including heavy metal pollution index(HPI),Nemerow index(NI)and contamination degree(CD),all demonstrated higher values at the nearby residential areas,suggesting coking activity could significantly impact the HMs distribution *** sources of HMs were identified by Positive Matrix Factorization(PMF)model,which indicated coal washing and coking emission were the dominant sources,accounted for 40.4%,and 31.0%,*** ingestionwas found to be the dominant exposure pathway with higher exposure dose to children than *** quotient(HQ)values were below 1.0,suggesting negligible non-carcinogenic health risks,while potential carcinogenic risks were from Pb and Ni with cancer risk(CR)values>10−*** Carlo simulation matched well with the calculated results with HMs concentrations to be the most sensitive *** study provides insights into understanding how the industrial coking activities can impact the HMs pollution characteristics in groundwater,thus facilitating the implement of HMs regulation in coking industries.

关键词： Coking industry Heavy metal Groundwater Spatial distribution Source apportionment Monte Carlo simulation

Real-world evidence on the efficacy and safety of vonoprazanamoxicillin dual therapy for Helicobacter pylori treatment in elderly patients

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World Journal of Gastroenterology 2025年第1期31卷 68-78页

作者： wen Gao Jing-wen Li Hui Ye Xue-Zhi Zhang Jian-Xiang Liu Hong Cheng Department of Gastroenterology Peking University First HospitalBeijing 100034China School of Medicine Tsinghua MedicineTsinghua UniversityBeijing 100034China Department of Traditional Chinese Medicine and Integrative Medicine Peking University First HospitalBeijing 100034China

BACKGROUND A dual therapy regimen containing amoxicillin is a common treatment option for the eradication of Helicobacter pylori(***).While substantial research supports the efficacy and safety of vonoprazan and amoxicillin(VA)dual therapy in the general population,there is still a lack of studies specifically focusing on its safety in elderly *** To evaluate efficacy and safety of VA dual therapy as first-line or rescue treatment for *** in elderly *** As a real-world retrospective study,data were collected from elderly patients aged 60 years and above who accepted VA dual therapy(vonoprazan 20 mg twice daily+amoxicillin 1000 mg thrice daily for 14 days)for *** eradication in the Department of Gastroenterology at Peking University First Hospital between June 2020 and January *** status was evaluated by^(13)C-urease breath test 6 weeks after *** adverse events(AEs)during treatment were *** In total,401 cases were ***-one cases were excluded due to loss to follow-up,lack of re-examination,or unwillingness to take *** total of 380 included cases comprised 250 who received VA dual therapy as first-line treatment and 130 who received VA dual therapy as rescue *** was successfully eradicated in 239 cases(95.6%)in the first-line treatment group and 116 cases(89.2%)in the rescue treatment *** overall incidence of AEs was 9.5%for both ***,9.2%of patients experienced an AE in the first-line treatment group and 10.0%in the rescue treatment *** patients discontinued treatment due to AE,with a discontinuation rate of 1.3%.No serious AE *** The VA dual therapy regimen as a first-line treatment and a rescue therapy was effective and safe for elderly patients aged 60 and older.

关键词： Helicobacter pylori Vonoprazan Amoxicillin Dual therapy Elderly

Flow behavior and dynamic softening mechanism of Pt−10Ir precious alloy

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Transactions of Nonferrous Metals Society of China 2025年第1期35卷 225-242页

作者： Xin-pei ZHANG Jun-jie HE Lin PI Quan FU wen-yan ZHOU Jun CHENG Sheng-wen BAI Xuan ZHOU Yi LIU Yong MAO Materials Genome Institute School of Materials and EnergyYunnan UniversityKunming 650091China Kunming Precious Materials&Technology Co. Ltd.Yunnan Precious Metals Laboratory Co.Ltd.Sino-Platinum Metals Co.Ltd.Kunming 650106China Kunming Institute of Precious Metals Kunming 650106China State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals Sino-Platinum Metals Co.Ltd.Kunming 650106China Shaanxi Key Laboratory of Biomedical Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The hot deformation behavior of Pt−10Ir alloy was studied under a wide range of deformation *** a low deformation temperature(950−1150℃),the softening mechanism is primarily dynamic *** addition,dynamic recrystallization by progressive lattice rotation near grain boundaries(DRX by LRGBs)and microshear bands assisted dynamic recrystallization(MSBs assisted DRX)coordinate the ***,it is difficult for the dynamic softening to offset the stain hardening due to a limited amount of DRXed *** a high deformation temperature(1250−1350℃),three main DRX mechanisms associated with strain rates occur:DRX by LRGBs,DRX by a homogeneous increase in misorientation(HIM)and geometric DRX(GDRX).With increasing strain,DRX by LRGBs is enhanced gradually under high strain rates;the“pinch-off”effect is enhanced at low strain rates,which was conducive to the formation of a uniform and fine microstructure.

关键词： platinum alloy hot deformation microstructure evolution dynamic recovery dynamic recrystallization