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Decreasing the CTE of Thermoplastic Polyimide by Blending with a Thermosetting System

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Chinese Journal of Polymer Science 2023年第6期41卷 956-961,I0010页

作者： Yu-Cheng Zi Gao-Jie Wu dong-xu pei Shu Guo Sheng-Li Qi Guo-Feng Tian De-Zhen Wu Key Laboratory of Carbon Fiber and Functional Polymers(Beijing University of Chemical Technology) Ministry of EducationBeijing 100029 China Institute of Analysis and Testing Beijing Academy of Science and Technology(Beijing Center For Physical&Chemical Analysis)Beijing 100089China

A series of thermoplastic polyimide resins with a low coefficient of thermal expansion(CTE)were prepared by blending a rigid resin system 3,3’,4,4’-biphenyltetracarboxylic dianhydride(BPDA)/p-phenylenediamine(PDA)with a flexible resin system 4,4’-[isopropylidenebis(pphenyleneoxy)]diphthalic anhydride(BPADA)/*** effects of the blending ratio on the macromolecular coil size,free volume,and CTE of the mixed system were *** mixing is carried out in the prepolymer poly(amide acid)(PAA)stage,which makes the two systems more compatible and is conducive to the formation of a semi-interpenetrating network structure between the rigid molecular chains and flexible molecular *** flexible structure of the BPADA/PDA system is used to ensure the melt processing *** rigid characteristics of the BPDA/PDA system can inhibit the movement of molecular chains and reduce the free volume fraction,thereby reducing the CTE *** the rigid system content reaches 30%,the CTE can be reduced to 38 ppm/*** method provides a new approach for studying low CTE thermoplastic polyimide resins.

关键词： value. system chains

Modification of hand reconstruction with unilateral foot donation

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Chinese Medical Journal 2007年第13期120卷 1206-1208页

作者： FAN Cun-yi LIU xu-dong CAI pei-hua JIANG pei-zhu YU Zhong-jia ZENG Bing-fang Department of Orthopaedic Surgery Shanghai Sixth People＇s Hospital Shanghai Jiao Tong University Shanghai 200233 China

Multiple toes transplantation is an effective method for-restoring the prehension of the ***, the thumb, index and middle finger are reconstructed by transferring a free big toe skin-nail flap with the second and third toes from a same foot. The great saphenous vein, superficial veins on the dorsum of the foot, the dorsalis pedis artery, and the first dorsal metatarsal artery are resected to be used as the donor pedicle. The arterial pedicle is freed up to the dorsal digital artery of the big and second toes. Both the second and third toes are supplied by the dorsal digital artery of the second toe on the tibial side. By using unilateral toe donation to reconstruct a digitless hand, we can preserve the normal form and function of the contralateral foot.

关键词： hand reconstruction surgery

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基于PRA方法的风险分析系统设计

系统仿真学报 2001年第6期13卷 756-758页

作者：董献洲徐培德国防科技大学人文与管理学院管理科学与工程系湖南长沙410073

探讨了应用概率风险评估（ＰＲＡ）方法进行工程项目风险分析的可行性，在此基础之上研究给出了一个基于ＰＲＡ方法的风险分析系统。该系统可用于工程项目的风险分析建模和评估，具有一定的理论及工程实用价值。

关键词：风险分析系统 PRA方法概率工程项目

玻璃离子应用于儿童乳牙龋齿充填的临床效果分析

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中国医疗器械信息 2017年第13期23卷 122-123页

作者：董培徐文靖天津市第二儿童医院天津300134

目的:对玻璃离子应用于儿童乳牙龋齿充填的临床效果进行深入探讨和剖析。方法:以本院2014年2月~2015年2月间所接收的单颗乳牙龋齿患者100例(100颗患牙)作为研究对象,将其随机分为观察组和对照组,每组各50颗患牙,对照组采取复合树脂充填... 详细信息

目的:对玻璃离子应用于儿童乳牙龋齿充填的临床效果进行深入探讨和剖析。方法:以本院2014年2月~2015年2月间所接收的单颗乳牙龋齿患者100例(100颗患牙)作为研究对象,将其随机分为观察组和对照组,每组各50颗患牙,对照组采取复合树脂充填,观察组患者采取玻璃离子充填,对两组患者充填半年成功率及失败原因、操作时间、牙本质过敏发生率以及2年成功率进行对比分析。结果:两组患者半年及2年成功率对比无显著差异,无统计学意义(P>0.05),观察组操作时间显著短于对照组,且牙本质过敏发生率(4.00%)显著低于对照组(14.00%),有统计学意义(P<0.05)。结论:对乳牙龋齿采取玻璃离子与复合树脂充填均具有良好的临床效果,但玻璃离子能够有效的预防牙本质过敏情况的发生,同时操作时间较短,对于儿童而言易于操作。

关键词：玻璃离子复合树脂儿童龋齿操作时间对比分析

An Unprecedented Efficiency with Approaching 21%Enabled by Additive‑Assisted Layer‑by‑Layer Processing in Organic Solar Cells

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Nano-Micro Letters 2025年第2期17卷 372-375页

作者： Shuai xu Youdi Zhang Yanna Sun pei Cheng Zhaoyang Yao Ning Li Long Ye Lijian Zuo Ke Gao Key Laboratory of Advanced Green Functional Materials College of ChemistryChangchun Normal UniversityChangchun 130032People’s Republic of China Shandong Provincial Key Laboratory for Science of Material Creation and Energy Conversion School of Chemistry and Chemical EngineeringShandong UniversityQingdao 266237People’s Republic of China College of Polymer Science and Engineering Sichuan UniversityChengdu 610065People’s Republic of China State Key Laboratory and Institute of Elemento‑Organic Chemistry Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer MaterialsRenewable Energy Conversion and Storage Center(RECAST)College of ChemistryNankai UniversityTianjin 300071People’s Republic of China Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of TechnologyGuangzhou 510640People’s Republic of China Tianjin Key Laboratory of Molecular Optoelectronic Sciences School of Materials Science and EngineeringTianjin UniversityTianjin 300350People’s Republic of China State Key Laboratory of Silicon Materials MOE Key Laboratory of Macromolecular Synthesis and FunctionalizationDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China

Recently published in Joule,Feng Liu and colleagues from Shanghai Jiaotong University reported a record-breaking 20.8%power conversion efficiency in organic solar cells(OSCs)with an interpenetrating fibril network active layer morphology,featuring a bulk p-in structure and proper vertical segregation achieved through additive-assisted layer-by-layer *** optimized hierarchical gradient fibrillar morphology and optical management synergistically facilitates exciton diffusion,reduces recombination losses,and enhances light capture *** approach not only offers a solution to achieving high-efficiency devices but also demonstrates the potential for commercial applications of OSCs.

关键词： Organic solar cells Additive-assisted layer-by-layer processing Three-dimensional fibril morphology Bulk p-i-n structure Optical management

1998年4月14～15日强沙尘暴过程分析

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高原气象 2001年第2期20卷 180-185页

作者：郑新江徐建芬罗敬宁孙兰东叶惠明许东蓓中国气象局国家卫星气象中心北京100081 甘肃省兰州中心气象台甘肃兰州730020

利用卫星云图 ,数值预报产品以及常规气象资料对 1998年 4月 14～ 15日发生在我国西部地区的沙尘暴天气进行了分析 ,指出本次过程发生在大气环流形势调整过程中 ,是由斜压槽及冷锋触发的。也重点分析了两个强沙尘暴中心的成因 ,发现第... 详细信息

利用卫星云图 ,数值预报产品以及常规气象资料对 1998年 4月 14～ 15日发生在我国西部地区的沙尘暴天气进行了分析 ,指出本次过程发生在大气环流形势调整过程中 ,是由斜压槽及冷锋触发的。也重点分析了两个强沙尘暴中心的成因 ,发现第一个强沙尘暴区是由加强的冷锋云带造成的 ,而第二个强沙尘暴区是由三条云带共同作用造成的。强沙尘暴区位于高空急流出口区右侧、5 0 0hPa正涡度中心下风方和次级反环流的上升区内。并用动力气象学原理做了初步讨论。

关键词：沙尘暴气象卫星卫星云图气象资料斜压槽天气过程分析大气环流冷锋

基于网络文化背景下高职院校学生管理工作研究

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科教文汇 2018年第17期 87-88页

作者：董慧徐普平裴立志铜陵职业技术学院管理系安徽铜陵244000

在网络高速发展的高职院校校园里,网络文化正在影响着学生的学习和生活,这给学生管理工作带来新的挑战。文章阐述了网络文化的特征,分析了网络文化对高职院校学生管理工作的影响,并对网络文化背景下高职院校学生管理工作提出对策。

关键词：网络文化学生管理对策

Depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 335-345页

作者： Feng Zhang Chenyang Zhang Linlin Wu Wei Sun Hongliang Zhang Jianhua Chen Yong pei Songjiang Li Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization Hunan International Joint Research Center for Efficient and Clean Utilization of Critical Metal Mineral ResourcesSchool of Minerals Processing and BioengineeringCentral South UniversityChangsha 410083China State Key Laboratory of Mineral Processing Beijing General Research Institute of Mining&MetallurgyBeijing 100160China Hunan Provincial Key Laboratory of Micro&Nano Materials Interfaces Science College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China School of Resources Environment and MaterialsGuangxi UniversityNanning 530004China Department of Chemistry Xiangtan UniversityXiangtan 411105China China Railway Resource Group Co.Ltd Beijing 102300China

The depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite still lacked in-depth ***,the depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite was further systematically investigated with experiments and density functional theory(DFT)*** X-ray photoelectric spectroscopy(XPS)results,DFT calculation results,and frontier molecular orbital analysis indicated that sulfite ions were difficult to be adsorbed on sphalerite surface,suggesting that sulfite ions achieved depression effects on sphalerite through other non-adsorption ***,the oxygen content in the surface of sphalerite treated with sulfite ions in creased,which enhanced the hydrophilicity of the sphalerite and further increased the difference in hydrophilicity between sphalerite and ***,sulfite ions were chelated with lead ions to form PbSO_(3)in *** hydrophilic PbSO_(3)was more easily adsorbed on sphalerite than *** interaction between sulfite ions and lead ions could effectively inhibit the activation of *** addition the UV spectrum showed that after adding sulfite ions,the peak of perxanthate in the sphalerite treated xanthate solution was significantly stronger than that in the galena with xanthate solution,indicating that xanthate interacted more readily with sulfite ions and oxygen mo lecules within the sphalerite system,leading to the formation of ***,sulfite ions hardly depressed the flotation of ga lena and could promote the flotation of galena to some *** study deepened the understanding of the depression mechanism o sulfite ions on sphalerite and Pb^(2+)activated sphalerite.

关键词： sphalerite galena sulfite ion density functional theory depression mechanism

Vertical-horizontal coupling nonlinear vibration characteristics of rolling mill under mixed lubrication

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Journal of Iron and Steel Research International 2021年第5期28卷 574-585页

作者： dong-xiao Hou Liang xu pei-ming Shi School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao 066004HebeiChina School of Electrical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

Considering the dynamic influence of the roll vibration on the lubricant film thickness in the rolling deformation area,nonlinear dynamic rolling forces related to film thickness in the vertical and horizontal directions were obtained based on the Karman balance *** on these dynamic rolling forces and the mechanical vibration of the rolling mill,a vertical-horizontal coupling nonlinear vibration dynamic model was *** amplitude-frequency equation of the main resonance was derived by using the multiple-scale *** last,the parameters of the 1780 rolling mill were used for numerical simulation,and the time-domain response curves of the system’s vibration displacement and lubricating film thickness under the steady and unsteady conditions were *** influences of parameters such as interface contact ratio,nonlinear parameters and external disturbances on the primary resonance frequency characteristics were obtained,which provided a theoretical reference for the suppression of rolling mill vibration.

关键词： Vertical-horizontal coupling Nonlinear vibration Mixed lubrication Dynamic rolling force Main resonance Amplitude-frequency characteristic