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The Effect of Trifluoroacetic Acid on Molecular Weight Determination of Polyesters:An in Situ NMR Investigation

Chinese Journal of Polymer Science 2021年第12期39卷 1590-1596页

作者： yan-yan tu Xue-Ting Wan Jie Huan Xiang Zhu Xiao-Hong Li Ying-Feng tu State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials College of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China

Due to the poor solubility of aromatic polyesters in comm on orga nic solve nts,trifluoroacetic acid is usually used as a co-solve nt to increase their solubility for ***,only few studies have reported the side reactions induced by *** present here the application of in situ 1H-NMR techniques to explore its effect on the hydroxyl end-groups,which are usually used for the molecular weight determination of polyesters by end-group estimation *** bis(2-hydroxyethyl)terephthalate(BHET)as model compound,quantitative NMR results show the peak integration of hydroxyethyl end-groups decreased with time via a pseudo-first-order kinetics in d-trifluoroacetic acid/d-chloroform mixture solvent(1:10,V:V).This is due to the esterification of hydroxyethyl groups with trifluoroacetic acid,revealed by the H-^(13)C gradient-enhanced heteronuclear multiple bond correlation(gHMBC)*** mixtures of dimethyl terephthalate and BHET with different molar ratios were used to represent poly(ethylene terephthalate)(PET)with different degrees of polymerization,and the effect of trifluoroacetic acid on the estimation of hydroxyethyl groups and subsequent molecular weight determination of polyesters was *** results show that if a relative error of 5%is allowed,the NMR measurements must be finished within 1.3 h of solution preparation at 25℃ in the mixture solve *** results were confirmed in PET sample,while in poly(ethyle ne adipate),the obtained esterifaction con stant is faster that those in aromatic *** results can be applied to other polymer systems with alcohol functionalized groups,and used as a guideline for the characterization of polyesters and polyethers by end-group estimation method.

关键词： Polyesters NMR spectroscopy Trifluoroacetic acid Molecular weight

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High-energy-density lithium manganese iron phosphate for lithium-ion batteries: Progresses, challenges, and prospects

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Journal of Energy Chemistry 2025年第1期100卷 1-17页

作者： Bokun Zhang Xiaoyun Wang Shuai Wang yan Li Libo Chen Handong Jiao Zhijing Yu Jiguo tu State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing Research Institute for Intelligent Wearable Systems The Hong Kong Polytechnic University Institute of Advanced Structure Technology Beijing Institute of Technology

The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion *** manganese iron phosphate (LiMnxFe1-xPO4) has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy *** LiMnxFe1-xPO4has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap *** review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMnxFe1-xPO4to analyze reaction processes accurately and guide material ***,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMnxFe1-xPO4,including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology ***,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are *** importantly,it is expected to provide key insights into the development of high-performance and stable LiMnxFe1-xPO4materials,to achieve practical energy storage requirements.

关键词： Semiconductor doping

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WHO 2016中枢神经系统肿瘤分类概述

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转化医学电子杂志 2017年第6期4卷 9-15页

作者：张鹏幸刘楠刘波延涂艳阳第四军医大学唐都医院实验外科陕西西安710038 西安市铁一中学陕西西安710054

随着对常见或罕见肿瘤发生的遗传学基础逐步阐明,主要以形态学概念作为定义标准的WHO 2007分类已经受到严峻挑战.病理学家通过结合组织病理学和分子特征,在WHO 2016中枢神经系统肿瘤分类中增加了部分新认识的肿瘤实体和变体,删除了部分... 详细信息

随着对常见或罕见肿瘤发生的遗传学基础逐步阐明,主要以形态学概念作为定义标准的WHO 2007分类已经受到严峻挑战.病理学家通过结合组织病理学和分子特征,在WHO 2016中枢神经系统肿瘤分类中增加了部分新认识的肿瘤实体和变体,删除了部分肿瘤类型或诊断术语,对某些肿瘤的诊断、分级及分型进行了修订.WHO肿瘤分级从2007版过渡到新的WHO 2016版的过程中临床神经病理学家接受挑战的同时,也通过很多新的诊断方法增加了对脑肿瘤的认识,新版的WHO 2016分类可能是从最早的WHO 1979分类标准以来变化最大的,因此,需要所有神经肿瘤领域的专家对这一新概念能有更充分的认识及理解.本文主要通过对WHO 2016中枢神经系统肿瘤分类进行解读,希望WHO 2016中枢神经系统肿瘤分类系统能使临床、实验室研究和流行病学的研究更便利,并且改善脑肿瘤患者的生存.

关键词： WHO 2016中枢神经系统肿瘤分类组织病理学分子特征

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FSD1 inhibits glioblastoma diffuse infiltration through restriction of HDAC6-mediated microtubule deacetylation

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Science China Life Sciences 2025年

作者： Dake Xiao Haowen Ran Lishu Chen Yuanyuan Li yan Cai Songyang Zhang Qinghui Qi Huiran Wu Cheng Zhang Shuailiang Cao Lanjuan Mi Haohao Huang Ji Qi Qiuying Han Haiqing tu Huiyan Li Tao Zhou Fangye Li Ailing Li Jianghong Man Nanhu Laboratory National Center of Biomedical Analysis School of Traditional Chinese Medicine Capital Medical University Department of Neurosurgery General Hospital of Central Theater Command of Chinese PLA School of Life and Health Sciences Huzhou College Department of Neurosurgery Beijing Fengtai Hospital Department of Neurosurgery First Medical Center of PLA General Hospital

The infiltration of glioblastoma multiforme(GBM) is predominantly characterized by diffuse spread, contributing significantly to therapy resistance and recurrence of GBM. In this study, we reveal that microtubule deacetylation, mediated through the downregulation of fibronectin type III and SPRY domain-containing 1(FSD1), plays a pivotal role in promoting GBM diffuse infiltration. FSD1 directly interacts with histone deacetylase 6(HDAC6) at its second catalytic domain, thereby impeding its deacetylase activity on α-tubulin and preventing microtubule deacetylation and depolymerization. This inhibitory interaction is disrupted upon phosphorylation of FSD1 at its Ser317 and Ser324 residues by activated CDK5, leading to FSD1 dissociation from microtubules and facilitating HDAC6-mediated α-tubulin deacetylation. Furthermore, increased expression of FSD1 or interference with FSD1 phosphorylation reduces microtubule deacetylation, suppresses invasion of GBM stem cells, and ultimately mitigates tumor infiltration in orthotopic GBM xenografts. Importantly, GBM tissues exhibit diminished levels of FSD1 expression, correlating with microtubule deacetylation and unfavorable clinical outcomes in GBM patients. These findings elucidate the mechanistic involvement of microtubule deacetylation in driving GBM cell invasion and offer potential avenues for managing GBM infiltration.

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Recent developments in nonferrous metals and related materials for biomedical applications in China:a review

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Rare Metals 2022年第5期41卷 1410-1433页

作者： Hai-Ling tu Hong-Bin Zhao yan-yan Fan Qing-Zhu Zhang State Key Laboratory of Advanced Materials for Smart Sensing GRINM Group Co.Ltd.Beijing 100088China China Academy of Space Technology Beijing 100094China Key Laboratory of Microelectronics Devices&Integrated Technology Institute of MicroelectronicsCASBeijing 100029China

Biomedical materials have received increasing attention in recent decades and have been used in medical applications to advance patient care,such as prosthetic implants,tissue repair and regeneration,drug delivery systems,pharmaceutical or biological therapy products,and sensitive diagnostic *** different types of biomedical materials,nonferrous metals and related materials(NMRMs)are important and attractive *** updating of biomedical NMRMs and devices heavily relies on original research and applicationoriented ***,we provide recent research findings and succinct insights into the developments in NMRMs for biomedical applications in China,including the use of titanium,magnesium,copper,zinc,cobalt,zirconium,hafnium,niobium,rhenium,tantalum,tungsten,silver,gold,platinum,palladium,their alloys and compounds,rare earths,high-entropy alloys,and liquid ***,the literature review concludes with several possible directions of NMRMs for new and future developments in biomedical engineering.

关键词： Nonferrous metal Biomedical Implants In vitro and in vivo Imaging Cancer treatment

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Sobolev Mapping of the Bergman Projections on Generalized Hartogs Triangles

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Acta Mathematica Sinica,English Series 2024年第2期40卷 451-466页

作者： Hong yan LIU Zhen Han tu School of Mathematics and Statistics Wuhan UniversityWuhan 430072P.R.China

In this paper,we investigate Sobolev mapping properties of the Bergman *** domain we focus on is defined byΩm/n:={(z,w)∈C^(1+N):|w1|<|z|m1/n1<1,…|wN|<|z|/m_(N)/n_(N)<1},where m=(m1,…mN)∈(Z^(+))^(N),n=(n1,…nN)∈(Z^(+))N,N∈Z^(+).Sobolev irregularity of the Bergman projections on 2 is *** also prove some Sobolev regularity results of the Bergman projections onΩm/n for m=(1,…1).

关键词： Bergman projections generalized Hartogs triangles Sobolev spaces

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Generalized Gr?tzsch ring function and generalized elliptic integrals

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Applied Mathematics(A Journal of Chinese Universities) 2016年第4期31卷 458-468页

作者： MA Xiao-yan QIU Song-liang tu Guo-yan Department of Mathematics Zhejiang Sci-Tech University Hangzhou 310018 China Tongji Zhejiang College Jiaxing 413000 China

Abstract. In this paper, we study the quotient of hypergeometric functions μα （r） in the theory of Ramanujan＇s generalized modular equation for α ∈（0, 1/2]. Several new inequalities are given for this and rela... 详细信息

关键词： Gaussian hypergeometric function generalized GrStzsch ring function generalized elliptic func-tion.

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Rules of distribution in a plastic zone of rocks surrounding a roadway affected by tectonic stress

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Mining Science and Technology 2010年第1期20卷 47-52页

作者： LU yan tu Shihao State Key Laboratory of Coal Resources and Mine Safety Xuzhou 221116 China School of Mining Engineering China University of Mining & Technology Xuzhou 221116 China

In order to study the rules of distribution in a plastic zone of rocks, surrounding a roadway, affected by tectonic stress, we first analyzed the mechanics of a roadway affected by tectonic stress and derived a theoretical formula for the plastic zone of rocks surrounding a roadway. We also analyzed the distribution characteristics of the plastic zone under different levels of tectonic stress, vertical pressure, cohesion and friction angle of the surrounding rock. Secondly, we used numerical simulation to analyze the range and shape features of the plastic zone of rocks surrounding the roadway, given different tectonic stress levels. Finally we used a rock drilling detector to carry out field measurements on the broken state of rock surrounding the roadway at the –700 substation and channels in the Xinzhuang mine of the Shenhuo mining area. Given the measured ground stress, we analyzed the relationship between tectonic stress and the distribution of this plastic zone. Our results show that the range of the plastic zone at the top and bottom of the roadway increases with an increase in tectonic stress and this increase is especially obvious at the roadway corner.

关键词： tectonic stress rock surrounding a roadway plastic zone

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Experimental and numerical study of installing a dune model in a 90° bend in the horizontal-vertical pneumatic conveying system

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Particuology 2023年第8期79卷 95-108页

作者： Zhenyu yang Fei yan Panpan tu Rui Zhu School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang212000China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang212000China

In the pneumatic conveying process,particles move to the bend under the influence of inertia to form a particle rope,which will cause serious wear between the particles and the pipe wall,and then the dune model is designed and installed in the 90° bend to reduce energy consumption and wear in this ***,the minimum pressure drop velocity of particles transported by different size dune models was obtained through experimental *** the energy saving mechanism of the dune model is studied by CFD-DEM *** experimental results show that the installation of the dune model reduces the minimum pressure drop *** numerical simulation results show that the number of collisions between the particles and the tube wall in the vertical tube decreases after the installation of the dune model,which reduces the energy ***,the increasing of tail size of the dune model is beneficial to the diffusion and acceleration of the particles in the vertical tube.

关键词： Pneumatic conveying Dune model CFD-DEM Minimum pressure drop velocity Recursiveanalysis

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The intensification of luminol electrochemiluminescence by metallic oxide nanoparticles

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Science China Chemistry 2011年第10期54卷 1640-1644页

作者： GUO WenYing yan JiLin tu YiFeng Institute of Analytical Chemistry Department of Chemistry Soochow University Suzhou 215123 China

In this work, the intensification of luminol electrochemiluminescence (ECL) by metallic oxide nanoparticles (MONPs), as ZnO, MnO2,In2O3 and TiO2 , under alkaline condition is reported and the related mechanism is studied. It is found that all four types of those MONPs exhibit the effect toward the ECL intensification of luminol. Furthermore, the silica sol-gel film is taken to immobilize the MONPs onto the platinum electrodes. The so-obtained modified electrodes also show the enhanced ECL and better signal/noise ratio, as well improved signal stability. Finally, the ECL reagent, luminol, is immobilized together with the MONPs onto the electrode surface to perform as the ECL sensor. On resulting sensors, good linear responses are obtained toward hydrogen peroxide. The mechanism of intensification of luminol ECL by MONPs is discussed in this paper. It is proposed that the ECL intensification can be attributed to the production of reactive oxygen species, as well as the adsorption of luminol on surface of MONPs.

关键词： electrochemiluminescence intensification luminal metallic oxide nanoparticles reactive oxygen species

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