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Synthesis of graphene quantum dots for their supramolecular polymorphic architectures

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Nano Research 2021年第4期14卷 1228-1231页

作者： Weifeng Chen Guo Lv qiyun zhou Jialu Shen Jie Cao Xiang Liu Zhongxu Dai Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials College of Materials and Chemical EngineeringChina Three Gorges UniversityYichang 443002China

How to regulate the supramolecular structures in the assembly of graphene quantum dots(GQDs)is still a great challenge to be ***,the GQDs of 1-3 layers with high quality are synthesized from the new precursor m-trihydroxybenzene in a green *** importantly,a strategy for designing the supramolecular structures of GQDs is demonstrated,and the novel supramolecular morphologies of GQDs have been constructed for the first ***,the supramolecular morphologies of GQDs can be well controlled by regulating the preparation conditions,and the formation mechanism of the branch-like supramolecular structure has been explained by the the diffusion-limited aggregation(DLA)*** work not only develops a new precoursor to synthesize GQDs,but also opens up an effective route toform the polymorphic supermolecules,thus greatly facilitating their potential applications.

关键词： graphene quantum dots supermolecule m-trihydroxybenzene synthesis the diffusion-limited aggregation

Spatio-temporal evolution and topographic gradient effect of land use and ecosystem service value in the Lhasa River Basin

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Journal of Mountain Science 2024年第6期21卷 2059-2074页

作者： zhou Jianwei FENG Bin WU Hua XU Tong CHEN Linna ZHAO Xinyong GUO qiyun LI Jiatong ZHANG Chenguang ZHU Kangcheng KONG Yuzhong School of Ecology and Environment Tibet UniversityLhasa 850000China School of Engineering Tibet UniversityLhasa 850000China Joint Laboratory of Plateau Surface Remote Sensing Tibet UniversityLhasa 850000China

The Lhasa River Basin forms an essential human settlement area in the southern part of the Qinghai-Tibet *** study employed ecosystem service value(ESV)evaluation model,terrain gradient grading,and Geodetector to analyze land use and ESV in the Lhasa River Basin from 1985 to *** findings reveal that:(1)From 1985 to 2020,grassland was the dominant land *** was a trend of grassland reduction and the expansion of other land types.(2)ESV has increased over the research period(with a total increase of 0.84%),with higher values in the southeast and lower values in the *** contributed the most to ESV,and climate regulation and hydrological regulation were the ecosystem services that contribute the most to ESV.(3)Natural factors like NDVI and altitude,as well as economic factors like population density and distance from roads,influenced the spatial differentiation of ESV,the explanatory power of NDVI reached up to *** interaction between factors had a greater impact than individual *** research results can provide theoretical support for national spatial planning and ecological environment protection in the Lhasa River Basin and other similar areas.

关键词： Ecosystem services value Land use Terrain gradient effect Lhasa River Basin Driving factors

Synthesis and Characterization of Waterborne Epoxy Curing Agent Modified by Silane

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Chinese Journal of Chemical Engineering 2007年第6期15卷 899-905页

作者：卢光岐孙建中周其云 State Key Laboratory of Chemical Engineering Department of Chemical and Biochemical EngineeringZhejiang UniversityHangzhou 310027China

A novel waterborne epoxy curing agent was prepared using 3-glycidoxypropyl trimethoxysilane （GPTMS） as a termination agent of adduct, which was synthesized by triethylene tetramine （TETA） and liquid epoxy resin （E-51）. The effects of the reaction temperature and time on the synthesis process were investigated experimentally. The particle size and the distribution of water dispersion of the curing agent were measured by dynamic light scattering（DLS）. The structure of the products was characterized by Fourier transform infrared spec-trometer （FTIR） and ^1H-nuclear magnetic resonance （^1H NMR）. The properties of the synthesized curing agent and the epoxy resin film cured by it were also measured. The results showed that the appropriate temperature for the synthesis of adduct was at 65-75℃ and the reaction time was 4-5h, and that the suitable reaction temperature of curing agent synthesis was 75-85℃ and the reaction time was 3-4h. When the mass ratios of GPTMS and acetic acid were 3%-5% and 5%-10% respectively, the hardness, water resistance and adhesion of the cured film were improved significantly.

关键词： waterborne epoxy curing agent silane modification

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低电子阻抗环氧树脂的合成

合成树脂及塑料 2006年第6期23卷 20-23页

作者：王哲孙建中周其云浙江大学化学工程与生物工程系化学工程联合国家重点实验室聚合反应工程实验室浙江杭州310027

采用金属钙络合离子中间体与双酚A型环氧树脂合成了低电子阻抗的环氧树脂,通过多元胺固化剂交联制备了低电子阻抗的环氧树脂固化物。用差示扫描量热法和热重分析法分别测试了低电子阻抗环氧树脂的固化过程与固化产物的热稳定性,考察了... 详细信息

采用金属钙络合离子中间体与双酚A型环氧树脂合成了低电子阻抗的环氧树脂,通过多元胺固化剂交联制备了低电子阻抗的环氧树脂固化物。用差示扫描量热法和热重分析法分别测试了低电子阻抗环氧树脂的固化过程与固化产物的热稳定性,考察了金属钙络合离子中间体与环氧树脂的用量比及反应时间对固化物的体积电阻率的影响。结果表明,引入金属钙络合离子中间体后,环氧树脂E-51固化物的冲击强度为12.1kJ/m2,弯曲强度为78.9MPa。

关键词：环氧树脂低电子阻抗合成

丁二烯气相聚合过程中的单体吸附效应和本征动力学模型

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化工学报 2001年第5期52卷 383-388页

作者：赵军子孙建中周其云潘祖仁浙江大学材料化工学院化工系浙江杭州310027

采用负载型稀土催化剂 ,在搅拌床反应器内进行丁二烯气相聚合动力学的研究 .考察了单体在聚合物小粒子中的吸附效应和单体压力与温度对聚合速率影响 ,在此基础上。

关键词：丁二烯气相聚合本征动力学模型单体吸附效应顺丁橡胶负载型稀土催化剂

Synthesis and Curing Properties of a Novel Novolac Curing Agent Containing Naphthyl and Dicyclopentadiene Moieties

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Chinese Journal of Chemical Engineering 2007年第1期15卷 127-131页

作者：任华孙建中吴斌杰周其云 State Key Laboratory of Chemical Engineering (Polymer Reaction Engineering Division) Department of Chemical and Biochemical Engineering Zhejiang University Hangzhou 310027 China

A novel novolac curing agent containing both naphthalene and dicyclopentadiene (DCPD) moieties was prepared to produce a highly heat-resistant cured polymer network. The chemical structure was characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, mass spectrometry, and gel permeation chro-matography analyses. The thermal properties of the resulting polymer from diglycidyl ether of bisphenol A epoxy resin cured with the novel curing agent were evaluated using dynamic mechanical thermal analysis and thermogra-vimetric analysis. Compared with the conventional curing agent, the resulting polymer cured with naphtha-lene/DCPD navolac shows considerable improvement in heat resistant properties such as higher glass transition temperature (Tg) and thermal stability. The result also shows better moisture resistance because of the hydrophobic nature of naphthalene/DCPD structure.

关键词： epoxy curing agent heat resistance naphthol dicyclopentadiene

不同家庭结构大学生父母教养方式与防御机制的关系研究

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中国特殊教育 2011年第7期 92-96页

作者：张小菊周绮云茹秀华北京联合大学应用文理学院北京100191

为了解当前大学生的性格特征与家庭教育的关系,在问卷调查的基础上,对不同家庭结构大学生的家庭教养方式、防御机制进行了相关分析,并通过回归分析对不成熟防御机制的家庭教养因子进行考察,结果表明:对于不同家庭结构和不同性别子女,父... 详细信息

为了解当前大学生的性格特征与家庭教育的关系,在问卷调查的基础上,对不同家庭结构大学生的家庭教养方式、防御机制进行了相关分析,并通过回归分析对不成熟防御机制的家庭教养因子进行考察,结果表明:对于不同家庭结构和不同性别子女,父亲的教养方式存在显著性差异;在母亲教养方式的情感温暖维度,仅性别存在显著性差异;不同家庭结构的大学生防御机制不存在显著差异;不同结构家庭,父母亲的情感、温暖对子女的不成熟防御机制有显著影响。在正常结构家庭中,母亲的情感温暖,惩罚严厉对子女的成熟防御机制有显著的预测作用。在特殊结构家庭中,父亲的拒绝、否认对子女的成熟防御机制有预测作用。在正常结构家庭中,母亲的拒绝否认对中间型防御机制有显著的预测作用。

关键词：不同家庭结构父母教养方式防御机制大学生

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二尖瓣成形术治疗二尖瓣关闭不全的临床分析

中国卫生标准管理 2021年第10期12卷 53-56页

作者：周琦云广西壮族自治区梧州市红十字会医院心胸外科广西梧州543002

目的以二尖瓣关闭不全患者为研究对象,分析二尖瓣成形术、二尖瓣置换术用于治疗的临床优势。方法选取2016年1月10日—2019年12月10日本院收治的42例二尖瓣关闭不全患者作为研究对象,便利抽样法分为两组,对照组采用二尖瓣置换术,观察组... 详细信息

目的以二尖瓣关闭不全患者为研究对象,分析二尖瓣成形术、二尖瓣置换术用于治疗的临床优势。方法选取2016年1月10日—2019年12月10日本院收治的42例二尖瓣关闭不全患者作为研究对象,便利抽样法分为两组,对照组采用二尖瓣置换术,观察组采用二尖瓣成形术治疗,比较两组治疗效果。结果观察组术后24 h输血量、住院时间均低于对照组(P0.05);观察组并发症总发生率4.76%低于对照组33.33%(P0.05);经治疗后观察组LVEF高于对照组,LVEDD、LVEDV低于对照组(P<0.05)。结论二尖瓣成形术治疗二尖瓣关闭不全临床疗效明显,可有效改善患者心脏功能。

关键词：二尖瓣成形术二尖瓣置换术二尖瓣关闭不全左心功能并发症预后

固溶处理对Fe-Cr-Ni-Al合金组织转变及元素扩散的影响

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金属热处理 2022年第5期47卷 98-104页

作者：周起云石增敏谢镐戴雷三峡大学材料与化工学院湖北宜昌443002 三峡大学水电机械设备设计与维护湖北省重点实验室湖北宜昌443002

利用OM、SEM等方法研究Fe-Cr-Ni-Al合金在固溶处理过程中元素的扩散以及相转变,同时针对不同降温速率的DSC数据建立了有关γ相转变的JMAK模型。结果表明,吸铸成形Fe-Cr-Ni-Al合金的室温组织基体为γ相+δ铁素体相;经过1150℃固溶处理,... 详细信息

利用OM、SEM等方法研究Fe-Cr-Ni-Al合金在固溶处理过程中元素的扩散以及相转变,同时针对不同降温速率的DSC数据建立了有关γ相转变的JMAK模型。结果表明,吸铸成形Fe-Cr-Ni-Al合金的室温组织基体为γ相+δ铁素体相;经过1150℃固溶处理,合金中γ相含量增高,δ铁素体相含量下降。在升温阶段发生了δ→γ的相转变,而在保温阶段发生了γ→δ的相转变;通过固溶处理,δ铁素体相、γ相分别演变成更为明显的富Cr相和富Ni相,不同分布位置的σ相之间Cr和Ni元素差异增大,与其所在的基体的成分偏析逐渐变小;通过奥氏体相转变的JMAK模型可知,冷却速度增大时,γ相转变的起始温度变低,同时转变的温度区间增大,反应所引起的能量变化也增大。

关键词： Fe-Cr-Ni-Al合金固溶处理元素扩散相转变 JMAK模型