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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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Atmospheric Particulate Matter 2.5(PM_(2.5))Induces Cell Damage and Pruritus in Human Skin

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Biomedical and Environmental Sciences 2024年第2期37卷 216-220页

作者： HE Qiao xue wan ting LI Li YI Fan LING Xiao GUO Miao Miao College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048China China Light Industry Cosmetics Key Laboratory Beijing Technology and Business UniversityBeijing 100048China Beijing Lan Divine Technology Co.LTD Beijing 100872China

With the accelerated rate of urbanization in recent years,air pollution has become an environmental problem that requires urgent resolution,almost all of the world’s population exposed to pollution on a daily *** the... 详细信息

关键词： pollution Skin Human

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改进瓶装液位高精度智能检测系统的设计

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仪表技术与传感器 2020年第2期 67-70页

作者：徐乐年薛婉婷于后瑞程国帅山东科技大学电子信息工程学院山东青岛266590 山东新巨龙能源有限责任公司山东菏泽274900

为满足生产线对瓶装液位检测的高精度、低成本、智能化的需求,依托先进传感器技术、嵌入式ARM处理器芯片以及数字信号处理方法,设计改进了基于变介质电容原理的液位在线检测系统。采用DDS技术产生稳定的可控信号源,通过电容式传感器对... 详细信息

为满足生产线对瓶装液位检测的高精度、低成本、智能化的需求,依托先进传感器技术、嵌入式ARM处理器芯片以及数字信号处理方法,设计改进了基于变介质电容原理的液位在线检测系统。采用DDS技术产生稳定的可控信号源,通过电容式传感器对液位信号进行采集处理,转变为数字信号,并结合BP神经网络进行温度补偿,最终利用相关算法将液位值计算出来;同时改进人机交互模块通过无线WIFI完成PC或手机端与检测系统的远程双向数据传输。实验结果表明,该检测系统的检测精度可达±1 mm,在精度、稳定性以及智能化方面均较之前的检测系统有了明显的提高。

关键词：液位检测介电常数 DDS信号发生器 BP神经网络人机交互

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供需两侧低碳政策下汽车制造商价格博弈非线性演化研究

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价值工程 2024年第23期43卷 4-6页

作者：赵丹郑芳悦薛婉婷安徽工业大学管理科学与工程学院马鞍山243032

在汽车市场新旧动能转换阶段,本文考虑供需两侧不同产业政策背景,基于有限理性建立了动态Bertrand博弈模型,并将积分交易价格、碳税额、碳普惠收益等低碳政策因素纳入模型,分析其复合牵引作用。结果表明:(1)供给侧双积分和碳税政策的叠... 详细信息

在汽车市场新旧动能转换阶段,本文考虑供需两侧不同产业政策背景,基于有限理性建立了动态Bertrand博弈模型,并将积分交易价格、碳税额、碳普惠收益等低碳政策因素纳入模型,分析其复合牵引作用。结果表明:(1)供给侧双积分和碳税政策的叠加应分阶段实行,现阶段两项政策若同时实施则太过于激进,不利于汽车市场全面发展。(2)需求侧碳普惠政策对于汽车市场新旧动能转换阶段的影响作用存在差异,因此政策的实施力度应根据市场情况进行动态调整。

关键词：价格竞争双积分政策低碳政策非线性演化混沌控制

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基于金属配位和主客体相互作用分级自组装构筑超分子凝胶

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高分子学报 2017年第1期27卷 93-100页

作者：陶杰林翠玲王兆龙魏斌华奇侠万雪婷邱化玉尹守春杭州师范大学材料与化学化工学院杭州310036

将金属配位和主客体相互作用引入到同1个超分子体系中,设计合成了2个超分子单体1和2.通过这2个超分子单体分级自组装形成的交联网状超分子聚合物构建了一种多重刺激响应性和良好自修复性能的超分子凝胶.同时,进一步将具有聚集诱导发光... 详细信息

将金属配位和主客体相互作用引入到同1个超分子体系中,设计合成了2个超分子单体1和2.通过这2个超分子单体分级自组装形成的交联网状超分子聚合物构建了一种多重刺激响应性和良好自修复性能的超分子凝胶.同时,进一步将具有聚集诱导发光性能的四苯乙烯引入到这种超分子体系中,以赋予超分子体系新颖的发光性能.单体分子1是由中间为双苯并24-冠-8的冠醚连接2个四苯基乙烯荧光生色团,两端为2个三联吡啶分子构成的1个主体分子.单体分子1两端的三联吡啶基团可以与过渡金属Zn(OTf)2进行金属配位形成线型超分子聚合物3;而中间的冠醚基团与双二级铵盐客体分子2通过主客体相互作用进一步形成交联超分子聚合物4.当该交联超分子聚合物的浓度达到30 mmol/L时,可形成荧光超分子聚合物凝胶.通过核磁共振(1H-NMR和DOSY)与黏度等测试方法,证明了线形和交联超分子聚合物的形成,并进一步通过流变的测试证明了超分子聚合物凝胶的形成及其良好的自修复性能.除此之外,由于引入的主客体相互作用以及金属配位固有的刺激响应性,该荧光超分子聚合物凝胶表现出对温度、p H值、K+离子和竞争配体的刺激响应性能.

关键词：超分子聚合物超分子凝胶分级自组装多重刺激响应自修复

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直流激励下桥丝型电火工品电弧发火预测模型

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含能材料 2024年第12期32卷 1334-1342页

作者：张博渊梁涛薛婉婷王哲穆亚茹谢彦召西安交通大学电工材料电气绝缘全国重点实验室陕西西安710049 西安交通大学电气工程学院陕西西安710049

为了研究桥丝型电火工品在直流激励下的电弧发火特性,预测其电弧发火安全阈值,采用模拟电荷法计算了脚‐壳二维切面电场强度,利用电击穿理论计算了脚‐壳电击穿系数,提出了桥丝型电火工品电弧发火的量化判据并建立模型。结果表明,环境... 详细信息

为了研究桥丝型电火工品在直流激励下的电弧发火特性,预测其电弧发火安全阈值,采用模拟电荷法计算了脚‐壳二维切面电场强度,利用电击穿理论计算了脚‐壳电击穿系数,提出了桥丝型电火工品电弧发火的量化判据并建立模型。结果表明,环境温度在25°左右,气压为大气压强时,桥丝型电火工品脚‐壳之间距离对其电弧发火阈值影响较大,脚‐壳距离越短,电弧发火阈值越低。桥丝型电火工品脚‐壳间电击穿电压预测模型计算结果与实测值相对误差不超过3.3%,且利用COMSOL仿真计算所得电击穿系数与预测模型计算结果相对误差约1%。

关键词：桥丝型电火工品模拟电荷法预测模型电弧发火缩比实验脚‐壳距离

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Synergistic effect of bonding heterogeneity and phonon localization in introducing excellent thermoelectric properties in layered heteroanionic NdZnSbO material

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Journal of Energy Chemistry 2025年第1期100卷 259-272页

作者： Da wan Shuwei Tang Shulin Bai Xiaodong Li Peng Ai wanrong Guo Tuo Zheng College of Materials Science and Engineering Liaoning Technical University Faculty of Chemistry Northeast Normal University

Layered rare-earth metal oxides, harnessing the dual properties of oxides and two-dimensional layered materials, exhibit remarkable thermal stability and quantum confinement effects. Therefore, this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound. The coexistence of weak interlayer van der Waals interactions, robust intralayer ionic bonding, and partial covalent bonding leads to remarkable bonding heterogeneity, which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction. The weakened chemical bonds induced by the antibonding states, together with the rattling-like behavior of the Zn atom, culminate in the profound anharmonicity in the layered NdZnSbO compound. The weakening bond and heavy element contribute to the softness of phonon modes, which significantly diminishes the phonon group velocity. The redistribution-dominated four-phonon scattering process spans a large optical gap, which effectively reduces the lattice thermal conductivity. The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06) functional in combination with spin–orbit coupling(SOC) effect. The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy, thus amplifying the power factor. Consequently, an optimal figure-of-merit(ZT) of 3.40 at 900 K is achieved for the n-type NdZnSbO compound. The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.

关键词： Bond strength (chemical)

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Quantum public-key crypto via EPR pairs

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 58-63页

作者： Xiang-Qun Fu Hong-Wei Li Jian-Hong Shi Tan Li wan-Su Bao Henan Key Laboratory of Quantum Information and Cryptography Information Engineering University Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China

With the development of quantum computing technology, quantum public-key cryptography is gradually becoming an alternative to the existing classical public-key cryptography. This paper designs a quantum trapdoor one-way function via EPR pairs and quantum measurements. Based on this, a new quantum public-key cryptosystem is presented, which offers forward security,and can resist the chosen-plaintext attack and chosen-ciphertext attack. Compared with the existing quantum public-key cryptos,eavesdropping can be automatically detected in this new quantum public-key cryptosystem under a necessary condition, which is also detailed in the paper.

关键词： quantum public-key crypto trapdoor one-way function EPR pairs

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Cholesterol metabolism: physiological versus pathological aspects in intracerebral hemorrhage

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Neural Regeneration Research 2025年第4期20卷 1015-1030页

作者： Ruoyu Huang Qiuyu Pang Lexin Zheng Jiaxi Lin Hanxi Li Lingbo wan Tao wang Department of Forensic Science School of Basic Medicine and Biological SciencesSuzhou Medicine College of Soochow UniversitySuzhouJiangsu ProvinceChina

Cholesterol is an important component of plasma membranes and participates in many basic life functions,such as the maintenance of cell membrane stability,the synthesis of steroid hormones,and *** plays a key role in the establishment and maintenance of the central nervous *** brain contains 20%of the whole body’s cholesterol,80%of which is located within myelin.A huge number of processes(e.g.,the sterol regulatory element-binding protein pathway and liver X receptor pathway)participate in the regulation of cholesterol metabolism in the brain via mechanisms that include cholesterol biosynthesis,intracellular transport,and *** brain injuries or diseases involving crosstalk among the processes above can affect normal cholesterol metabolism to induce detrimental ***,we hypothesized that cholesterol-related molecules and pathways can serve as therapeutic targets for central nervous system *** hemorrhage is the most severe hemorrhagic stroke subtype,with high mortality and *** cholesterol levels are associated with the risk of intracerebral ***,secondary pathological changes after intracerebral hemorrhage are associated with cholesterol metabolism dysregulation,such as neuroinflammation,demyelination,and multiple types of programmed cell *** cholesterol accumulation in the brain has been found after intracerebral *** this paper,we review normal cholesterol metabolism in the central nervous system,the mechanisms known to participate in the disturbance of cholesterol metabolism after intracerebral hemorrhage,and the links between cholesterol metabolism and cell *** also review several possible and constructive therapeutic targets identified based on cholesterol metabolism to provide cholesterol-based perspectives and a reference for those interested in the treatment of intracerebral hemorrhage.

关键词： cell death cholesterol metabolism intracerebral hemorrhage myelination therapeutic target

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Aligned Ion Conduction Pathway of Polyrotaxane‑Based Electrolyte with Dispersed Hydrophobic Chains for Solid‑State Lithium–Oxygen Batteries

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Nano-Micro Letters 2025年第2期17卷 169-186页

作者： Bitgaram Kim Myeong‑Chang Sung Gwang‑Hee Lee Byoungjoon Hwang Sojung Seo Ji‑Hun Seo Dong‑wan Kim Department of Materials Science and Engineering Korea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea School of Civil Environmental and Architectural EngineeringKorea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea Materials Science and Chemical Engineering Center Institute for Advanced Engineering(IAE)Yongin 17180Republic of Korea

A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety *** study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves ***-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain *** this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 *** situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen *** situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability *** present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.

关键词： Solid polymer electrolyte Lithium-oxygen batteries Polyrotaxane ion conductivity Hydrophobic chain

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