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Enhanced Crystallization of Poly(butylene adipate-co-terephthalate)by a Self-assembly Nucleating Agent

Chinese Journal of Polymer Science 2024年第5期42卷 663-674,I0010页

作者： Cheng Zhou Kun Chen Zi-Heng Zhang Meng-Fan Jing Chun-Tai Liu chang-yu shen Ya-Ming Wang State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou450002China

Poly(butylene adipate-co-terephthalate)(PBAT)is a promising biodegradable flexible polymer but suffers from slow crystallization rate,making it less attractive for some applications like the injection-molded products in comparison with low-density polyethylene(LDPE).This work aimed to accelerate the crystallization of PBAT by adding a self-assembly nucleating agent octamethylenedicarboxylic dibenzoylhydrazide(OMBH).PBAT/OMBH composites with various OMBH contents(0 wt%,0.5 wt%,0.7 wt%,1 wt%,2 wt%,3 wt%and 5 wt%)were prepared through *** effect of OMBH on the crystallization behavior,morphologies and mechanical properties of PBAT was *** highest nucleation efficiency value of 59.6%was achieved for PBAT with 0.7 wt%OMBH,much higher than that of 22.7%for PBAT with 0.7 wt%*** force microscopy results showed that OMBH formed fine fibers and induced the formation of transcrystalline layers of *** transform infrared spectroscopy(FTIR)combined with two-dimensional correlation spectra suggested that the intermolecular dipole-dipole N—H…O=C interactions but not hydrogen bond between OMBH and PBAT promoted the crystallization of PBAT in the initial period of *** presence of OMBH did not change the crystal form of PBAT but had positive contribution in enhancing its crystallinity and mechanical *** work is essential for preparing PBAT with high crystallization rate,enhancing its potential applications in injection-molded products.

关键词： Poly(butylene adipate-co-terephthalate) Biodegradable Self-assembly nucleating agent Crystallization

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伴主观视觉垂直偏斜的急性脑干梗死患者前庭康复治疗效果分析

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中国现代神经疾病杂志 2024年第4期24卷 273-279页

作者：赵仟仟尹苗苗李雅晴黄茂娟于长申张玥巫嘉陵天津医科大学神经内外科及神经康复临床学院 300070 天津市环湖医院康复医学科 300350 天津市环湖医院神经内科 300350

目的探讨前庭康复治疗对伴主观视觉垂直偏斜的急性脑干梗死患者主观视觉垂直、平衡信心、头晕/眩晕程度及步行能力的疗效及其相关性。方法纳入2022年7月至2023年7月天津市环湖医院收治的45例伴主观视觉垂直偏斜的急性脑干梗死患者,随机... 详细信息

目的探讨前庭康复治疗对伴主观视觉垂直偏斜的急性脑干梗死患者主观视觉垂直、平衡信心、头晕/眩晕程度及步行能力的疗效及其相关性。方法纳入2022年7月至2023年7月天津市环湖医院收治的45例伴主观视觉垂直偏斜的急性脑干梗死患者,随机分为前庭康复组(25例)和常规康复组(20例),于康复治疗前和治疗后2周采用水桶试验测量主观视觉垂直偏斜角度,特异性活动平衡信心量表(ABC)评估患者完成各项任务时平衡信心,头晕/眩晕视觉模拟评分(VAS)评估头晕/眩晕程度,功能性步行分级量表(FAC)评估步行能力。结果前庭康复组与常规康复组主观视觉垂直偏斜角度(F=4.356,P=0.043)、ABC评分(F=4.389,P=0.042)、头晕/眩晕VAS评分(F=4.138,P=0.048)差异有统计学意义,其中治疗后前庭康复治疗组主观视觉垂直偏斜角度(t=-2.139,P=0.038)、头晕/眩晕VAS评分(t=-2.952,P=0.005)低于常规康复治疗组,ABC评分高于常规康复治疗组(t=2.920,P=0.006);两组治疗前后主观视觉垂直偏斜角度(F=196.923,P=0.000)、ABC评分(F=89.050,P=0.000)、头晕/眩晕VAS评分(F=81.803,P=0.000)、FAC分级(F=72.866,P=0.000)差异亦有统计学意义,其中前庭康复组和常规康复组治疗后主观视觉垂直偏斜角度(t=0.763,P=0.000;t=0.972,P=0.000)和头晕/眩晕VAS评分(t=8.815,P=0.000;t=5.107,P=0.000)低于治疗前,ABC评分(t=0.689,P=0.001;t=0.703,P=0.001)和FAC分级(t=-6.721,P=0.000;t=-5.772,P=0.000)高于治疗前。相关分析显示,伴主观视觉垂直偏斜的急性脑干梗死患者治疗前主观视觉垂直偏斜角度与头晕/眩晕VAS评分呈正相关(r=0.627,P=0.000)。结论前庭康复治疗可以有效改善伴主观视觉垂直偏斜的急性脑干梗死患者主观视觉垂直偏斜、平衡信心、头晕/眩晕症状,且主观视觉垂直偏斜角度与头晕/眩晕程度密切相关。

关键词：脑干梗死重力感知神经康复前庭迷路

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Effect of Physical Aging on Heterogeneity of Poly(ε-caprolactone)Toughening Poly(lactic acid)Probed by Nanomechanical Mapping

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高分子科学：英文版 2023年第1期41卷 143-152页

作者： Bo-Wen Wang Hao Liu Jin Ying Chun-Tai Liu chang-yu shen Ya-Ming Wang Key Laboratory of Materials Processing&Mold(Zhengzhou University) Ministry of EducationNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou450002China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou450001China

Poly(lactic acid) (PLA) is a promising bio-based environmentally-friendly plastic. Nevertheless, the physical aging-induced brittleness of PLA limits its widespread applications. Blending with immiscible ductile polymer is an effective way to toughen PLA. However, the underlying details of the toughening mechanism and, in particular, the effect of physical aging are not well understood. Herein, atomic force microscopy (AFM) based nanomechanical mapping technology was utilized to visualize the differences in the deformation mechanisms between unaged and aged PLA/poly(ε-caprolactone) (PCL) blend upon uniaxial drawing. Results show that physical aging has a significant effect on the microscopic Young’s modulus and its distribution of PLA matrix, resulting in a highly heterogeneous response of the PLA/PCL blend to external stress and affecting the mechanical properties of the PLA phase under different extensions. This work provides a new experimental basis for understanding the effect of physical aging on the mechanical properties of PLA-based materials.

关键词： Poly(lactic acid) Blends Toughening Physical aging Nanomechanical mapping

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Self-nucleation of Patterned Polymer Thin Films Defined by Soft Lithography

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Chinese Journal of Polymer Science 2022年第6期40卷 651-657页

作者： Ze-Qian Wang Yi-Meng Wang Xing-yu Wang Bing-Hua Wang Jing-Bo Chen chang-yu shen Bin Zhang School of Materials Science&Engineering Zhengzhou UniversityZhengzhou 450002China

The nucleation of crystals is often a determining step in the phase transition of materials,but it remains a challenge to control the density and specific location of nuclei *** we fabricated the isolated single crystals of uniform size with controlled number density and spatial distribution by self-nucleation of patterned dendritic *** lithography creates the periodic void space on the surface of poly(ethylene oxide)-b-poly(2-vinyl pyridine)(PEO-b-P2VP)block copolymer thin films and provides spatial redistribution of polymers,leading to the preferential nucleation and subsequent oriented growth of dendrites in the periodic arrays of imprinted *** morphology and thermal stability of the patterned crystals can be adjusted by tuning embossing conditions(e.g.,temperature and pressure).Furthermore,in the self-nucleation technique,the annealing temperature and heating rate are used as the feedback parameters to map the number density and spatial distribution of regrown single *** PEO-b-P2VP crystalline pattern can be used as a versatile template for large-area manufacturing of selective metal patterns for electronic devices and other applications.

关键词： Self-nucleation Imprint lithography Atomic force microscopy Crystallization pattern Selective metal pattern

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Garnet-type solid-state electrolytes:crystal structure,interfacial challenges and controlling strategies

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Rare Metals 2023年第10期42卷 3177-3200页

作者： Ting-Ting Wu Sijie Guo Bing Li chang-yu shen Xian-Hu Liu An-Min Cao National Engineering Research Center for Advanced Polymer Processing Technology Key Laboratory of Advanced Material Processing&Mold(Ministry of Education)Zhengzhou UniversityZhengzhou450002China CAS Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of Sciences(CAS)Beijing100190China University of Chinese Academy of Sciences Beijing100049China

All-solid-state batteries(ASSBs) hold great promise for next-generation energy storage technologies owing to their advantage in different aspects such as energy density,safety,and wide temperature ***,the use of solid-state electrolytes(SSEs) instead of liquid ones meanwhile brings serious concerns related to the point-to-point contact between SSEs and electrodes,which is known to result in high interface resistance and inhomogeneous distribution of charges during the Li^(+)plating/stripping process,eventually leading to a premature failure of *** review focuses on the garnet-type SSEs in the formula of Li_(7)La_(3)Zr_(2)O_(12)(LLZO),and discusses the structure-performance relationship of this ceramic electrolyte in detail to achieve a clear understanding of its Li^(+)transmission ***,the challenges of cubic phase LLZO(c-LLZO) for their application in solidstate batteries(SSBs) are demonstrated by the Li/LLZO interface,which features the importance of Li metal wettability and dendrite suppression for sustainable ***,this review summarizes the recent research strategies to combat these contact issues at the Li/LLZO interface,highlighting the essential role played by surface modification of LLZO *** the obtained insights,perspectives for future research on LLZO to accelerate its potential development of SSBs in commercialized applications are also provided.

关键词： Solid-state electrolytes(SSEs) Garnet-type electrolytes Li^(+)ion conductivity Interface engineering Lithium dendrites

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One-step and Continuous Fabrication of Coaxial Piezoelectric Fiber for Sensing Application

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Chinese Journal of Polymer Science 2023年第11期41卷 1778-1785,I0009页

作者： Shuai-Shuai Gui Bing-Xu Da Fei Peng Guo-Qiang Zheng Kun Dai Chun-Tai Liu chang-yu shen College of Materials Science and Engineering Key Laboratory of Material Processing and Mold(Ministry of Education)Henan Key Laboratory of Advanced Nylon Materials and ApplicationZhengzhou UniversityZhengzhou 450001China

Although there has been rapid advancement in piezoelectric sensors,challenges still remain in developing wearable piezoelectric sensors by a one-step,continuous and environmentally friendly *** this work,a 1D flexible coaxial piezoelectric fiber was directly fabricated by melt extrusion molding,whose core and sheath layer are respectively slender steel wire(i.e.,electrode)and PVDF(i.e.,piezoelectric layer).Moreover,such 1D flexible coaxial piezoelectric fiber possesses short response time and high sensitivity,which can be used as a selfpowered sensor for bending and vibration *** interestingly,such 1D flexible coaxial piezoelectric fiber(1D-PFs)can be further endowed with 3D helical ***,a wearable and washable motion monitoring system can be constructed via braiding such 3D helical piezoelectric fiber(3D-PF)into commercial *** work paves a new way for developing 1D and 3D piezoelectric fibers through a one-step,continuous and environmentally friendly method,showing potential applications in the field of sensing and wearable electronics.

关键词： Coaxial piezoelectric fiber Melt extrusion molding Bending and vibration sensing Motion monitoring system

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Investigation of Ce/BEA as a passive NO_(x)adsorber:*** aging deactivation mechanism

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Journal of Rare Earths 2024年第8期42卷 1524-1530,I0004页

作者： Yiying Ding Minghui yu Xiaojie yu Meiqing shen Jianqiang Wang Jun Wang Gurong shen School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China School of Materials Science and Engineering Tianjin UniversityTianjin300350China National Rare Earth Catalysis Research Institute Dongying257000China

Ce/BEA has the potential to be applied as a novel passive NO_(x)absorber(PNA)in the after-treatment of vehicles due to its considerable NO_(x)storage ***,as a vehicle exhaust after-treatment material,it must withstand the test of long-term hydrothermal *** work examined the deactivation mechanism of Ce/BEA during hydrothermal aging.3.0 wt%Ce/BEA was prepared using the ionexchange method,and then subjected to hydrothermal treatment at 650℃with 10%H_(2)O for 1-12 h to obtain samples with different aging *** comparison,the H-BEA support was aged under the same ***-Emmett-Teller(BET)method,X-ray diffraction(XRD),NH_(3)temperature programmed reduction(NH_(3)-TPD),^(27)Al MAS nuclear magnetic resonance(^(27)Al MAS NMR),H_(2)temperature programmed reduction(H_(2)-TPR),and high resolution-transmission electron microscopy(HR-TEM)were performed to characterize the changes in PNA performance,structure,Ce species,and *** HR-TEM and H_(2)-TPR results show that CeO_(x)particles appear after hydrothermal aging,which results from the detachment and aggregation of active Ce *** on the^(27)Al MAS NMR results,we conclude that BEA zeolite dealumination leads to the loss of acidic sites and the transformation of active Ce species on the acidic sites into the less active CeO_(x).This is the primary reason for the hydrothermal aging deactivation of Ce/BEA.

关键词： Passive NO_(x)adsorber Ce/BEA Hydrothermal aging CeO_(x) Dealumination Rare earths

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Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

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Nuclear Science and Techniques 2024年第6期35卷 78-89页

作者： Xian-Lin Yang chang-Lin Lan yu-Ting Wei Yi Zhang Gong Jiang Bo Xie yu Liu Hong-Tao shen Xiao-Jun Sun School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology Guangxi Normal UniversityGuilin 541004China

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great *** address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion *** the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He ***^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMS at the Institute of Geochemistry,Chinese Academy of *** neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb *** measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature *** newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental *** obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

关键词： 14-MeV neutron ^(27)Al(n,2n)^(26)Al Cross section AMS

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A toroidal SAW gyroscope with focused IDTs for sensitivity enhancement

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Microsystems & Nanoengineering 2024年第2期10卷 47-56页

作者： Lu Tian Haitao Zhao Qiang shen Honglong chang Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical UniversityXi’an710072China

A surface acoustic wave(SAW)gyroscope measures the rate of rotational angular velocity by exploiting a phenomenon known as the SAW gyroscope *** a gyroscope is a great candidate for application in harsh environments because of the simplification of the suspension vibration mechanism necessary for traditional microelectromechanical system(MEMS)***,for the first time,we propose a novel toroidal standing-wave-mode SAW gyroscope using focused interdigitated transducers(FIDTs).Unlike traditional SAW gyroscopes that use linear IDTs to generate surface acoustic waves,which cause beam deflection and result in energy dissipation,this study uses FIDTs to concentrate the SAW energy based on structural features,resulting in better focusing performance and increased SAW *** experimental results reveal that the sensitivity of the structure is 1.51µV/(°/s),and the bias instability is 0.77°/s,which are improved by an order of magnitude compared to those of a traditional SAW ***,the FIDT component can enhance the performance of the SAW gyroscope,demonstrating its superiority for angular velocity *** work provides new insights into improving the sensitivity and performance of SAW gyroscopes.

关键词： angular deflection gyroscope

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Investigation of Ce/BEA as a passive NO_(x)adsorber:*** occurrences of cerium and adsorption behavior

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Journal of Rare Earths 2024年第7期42卷 1265-1271,I0003页

作者： Minghui yu Yiying Ding Xiaojie yu Siwei Yan Meiqing shen Jianqiang Wang Jun Wang Gurong shen School of Materials Science and Engineering Tianjin UniversityTianjin300350China School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China National Rare Earth Catalysis Research Institute Dongying257000China

Ce/BEA has great potential as a passive NO_(x)absorber(PNA)to reduce the NO_(x)emissions during the cold start phase especially in diesel engine for its high resistance to CO and suitable NO_(x)desorption temperature ***,as a novel material,its physical and chemical properties still remain *** this work,Ce/BEA was synthesized by ion-exchange method to identify the active species in NO_(x)adsorption,compared with aggregated Ce species in Ce/SiAlO_(x) prepared by impregnation method.X-ray diffraction(XRD),high resolution-transmission electron microscopy(HR-TEM)and aberration-corrected-scanning transmission electron microscopy(AC-STEM)were performed to confirm the isolated single atom formation of Ce species in Ce/***-vis diffraction reflection spectra(DRS)and X-ray photoelectron spectroscopy(XPS)were conducted to find the difference of chemical environment between the isolated Ce species and aggregated *** performance evaluation and temperature programmed reduction of hydrogen(H_(2)-TPR)results show the high NO_(x)storage capacity and active oxygen species quantity in Ce/*** is also found that the main NO_(x)adsorption species are Ce^(4+)-O^(∗)rather than Ce^(3+).NO_(x)-diffuse reflectance infrared Fourier transform spectroscopy(NO_(x)-DRIFTS)confirms that the bidentate nitrite species are the critical NO_(x)adsorption intermediates and the conception of NO_(x)adsorption and desorption processes is proposed.

关键词： Passive NO_(x)absorber Ce/BEA Isolated Ce species Rare earths

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