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Constructing a biomimetic robust bi-layered hydrophilic lubrication coating on surface of silicone elastomer

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Friction 2022年第7期10卷 1046-1060页

作者： Luyao GAO Xiaoduo ZHAO Shuanhong MA Zhengfeng MA Meirong CAI yong-min liang Feng ZHOU School of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou 730000China Lanzhou Institute of Chemical Physics Chinese Academy of SciencesLanzhou 730000China

Silicone elastomers-based materials have been extensively involved in the field of biomedical devices,while their use is extremely restricted due to the poor surface lubricity and inherent *** paper describes a novel strategy for generating a robust layered soft matter lubrication coating on the surface of the polydimethylsiloxane(PDMS)silicone elastomer,by entangling thick polyzwitterionic polyelectrolyte brush of poly(sulfobetaine methacrylate)(PSBMA)into the sub-surface of the initiator-embedded stiff hydrogel coating layer of P(AAm-co-AA-co-HEMA-Br)/Fe,to achieve a unified low friction and high load-bearing ***,the stiff hydrogel layer with controllable thickness is covalently anchored on the surface of PDMS by adding iron powder to provide catalytic sites through surface catalytically initiated radical polymerization(SCIRP)method and provides high load-bearing capacity,while the topmost brush/hydrogel composite layer is highly effective for aqueous *** synergy effects are capable of attaining low friction coefficient(COFs)under wide range of loaded condition in water environment with steel ball as sliding ***,the influence of mechanical modulus of the stiff hydrogel layer on the lubrication performance of layered coating is investigated,for which the COF is the lowest only when the modulus of the stiff hydrogel layer well matches the PDMS ***,the COF of the modified PDMS could remain low friction(COF<0.05)stably after encountering 50,000 sliding cycles under 10 N ***,the surface wear characterizations prove the robustness of the layered lubricating *** work provides a new route for engineering lubricious silicon elastomer with low friction,high load-bearing capacity,and considerable durability.

关键词： surface modification silicone elastomer layered lubrication coating hydrogels polyzwitterionic brush

Reductive Coupling of Aryl Halides via C-H Activation of Indene

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Chinese Journal of Chemistry 2021年第6期39卷 1573-1579页

作者： Bo-Sheng Zhang Ying-Hui Yang Fan Wang Xue-Ya Gou Xi-Cun Wang yong-min liang Yuke Li Zheng-Jun Quan College of Chemistry and Chemical Engineering Gonsu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional MaterialsNorthwest Normal UniversityLanzhouGansu 730070China State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhouGansu 730000China Department of Chemistry and Centre for Scientific Modeling and Computation Chinese University of Hong KongShatinHong KongChina

This paper describes the first case of a reductive coupling reaction with indene,a non-heteroatom olefin used as a reducing *** scope of the substrate is *** homo-coupling,cross-coupling,and synthesis of 12 and 14-membered rings were *** control experiment,indene-product curve and density functional theory calculations showed that the η^(3)-palladium indene intermediate was formed by C-H activation in the presence of cesium *** speculate that the final product was obtained through a Pd(IV)intermediate or aryl ligand *** addition,we excluded the formation of palladium anion(Pd(0)^(-))intermediates.

关键词： C-C coupling Palladium Reduction Indene C-H activation

Palladium-Catalyzed One-Step Synthesis of Stereodefined Difunctionalized Glycals

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CCS Chemistry 2023年第3期5卷 741-749页

作者： Xiao-Ping Gong Yuke Li Hong-Chao Liu Zhe Zhang Zhi-Jie Niu Ya-Nan Ding Yang An Xi Chen Yan-Chong Huang Rui-Qiang Jiao Xue-Yuan Liu yong-min liang State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000 Department of Chemistry Centre for Scientific Modeling and ComputationChinese University of Hong KongShatinHong Kong 999077

Efficiently modifying glycals by directly introducing functional groups into their double bonds is a longstanding ***,the strategy of introducing two different functional groups into 1-iodoglycals to obtain modified glycals in one step through palladium catalysis was reported for the first time,and the modified glycals contained stereodefined tetrasubstituted *** this method,various difunctionalized glycals that were difficult to form by other routes were synthesized in moderate to good *** experiments and density functional theory calculations show that the palladium catalyst played dual roles in this transformation,namely,inducing nucleophilic substitution and catalyzing Suzuki *** reaction intermediate was isolated and confirmed by X-ray crystallographic ***,the gram-scale synthesis and facile deprotection of the target compound enhances the practicality of this strategy.

关键词： palladium catalysis glycals tetrasubstitute olefins difunctionalization stereodefined threecomponent

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“酒店收益管理”教学改革探讨

四川旅游学院学报 2016年第4期 86-88页

作者：雍梁敏三亚学院海南三亚572000

基于社会对收益管理实用型人才需求,"酒店收益管理"课程实施教学改革,以能力培养为中心,完善"酒店收益管理"教学大纲,构建实践教学模式,完善实践教学考核体系,达到培养符合市场需求的收益管理人才。

关键词：酒店收益管理实践教学能力培养教学改革

响应面法优化木薯叶中黄酮类化合物的浸提条件

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食品研究与开发 2017年第10期38卷 63-67页

作者：雍梁敏刘畅刘石生三亚学院海南三亚572022 海南大学食品学院海南海口570228

采用碳酸氢钠浸提木薯叶中黄酮类化合物,并用Na NO_2-Al(NO_3)_3比色法测定黄酮类化合物的含量。通过Box-Benhnken试验设计及响应面分析法对影响木薯叶浸提黄酮类化合物的主要因素进行条件优化。结果表明最优条件为:加水量30.77 m L/g,... 详细信息

采用碳酸氢钠浸提木薯叶中黄酮类化合物,并用Na NO_2-Al(NO_3)_3比色法测定黄酮类化合物的含量。通过Box-Benhnken试验设计及响应面分析法对影响木薯叶浸提黄酮类化合物的主要因素进行条件优化。结果表明最优条件为:加水量30.77 m L/g,浸提温度79.65℃,浸提时间11.82 min,Na HCO_3添加量0.03 g。在此工艺条件下浸提得到的黄酮类化合物含量为1 172.17 mg/100 g。

关键词：木薯叶黄酮类化合物碳酸氢钠响应面

冷冻结晶法分离橡胶籽油中多不和脂肪酸的研究

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食品工业 2014年第7期35卷 189-192页

作者：雍梁敏王丽蓉刘石生海南大学热带生物资源教育部重点实验室海口570228 海南大学食品学院海口570228

以橡胶籽油为原料,经皂化制得混合脂肪酸,采用低温冷冻结晶法分离多不饱和脂肪酸(PUFAs)。研究结果表明,低温冷冻结晶法分离PUFAs最佳工艺条件为:溶剂为正己烷,m(混合脂肪酸)︰V(正己烷)=1︰10,结晶温度为-70℃,冷冻时间为1.5 h,固液分... 详细信息

以橡胶籽油为原料,经皂化制得混合脂肪酸,采用低温冷冻结晶法分离多不饱和脂肪酸(PUFAs)。研究结果表明,低温冷冻结晶法分离PUFAs最佳工艺条件为:溶剂为正己烷,m(混合脂肪酸)︰V(正己烷)=1︰10,结晶温度为-70℃,冷冻时间为1.5 h,固液分离方式为-18℃冷冻离心3 min。最佳条件下,经低温冷冻结晶法处理,总不饱和脂肪酸含量达98.67%,PUFAs含量由原来的58.12%提高到71.52%。

关键词：橡胶籽油多不饱和脂肪酸分离冷冻结晶法

壳聚糖微球固定化橡胶籽β-葡萄糖苷酶的研究

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食品工业 2014年第5期35卷 119-122页

作者：王丽蓉雍梁敏刘石生海南大学热带生物资源教育部重点实验室海口570228 海南大学食品学院海口570228

将源自橡胶籽的β-葡萄糖苷酶采用戊二醛交联吸附的方法固定到壳聚糖微球上,在单因素试验基础上,以戊二醛体积分数、反应pH及加酶量为自变量,酶活回收率为响应值,采用响应面法对固定化工艺进行优化。最优固定化工艺为:壳聚糖微球在0.01... 详细信息

将源自橡胶籽的β-葡萄糖苷酶采用戊二醛交联吸附的方法固定到壳聚糖微球上,在单因素试验基础上,以戊二醛体积分数、反应pH及加酶量为自变量,酶活回收率为响应值,采用响应面法对固定化工艺进行优化。最优固定化工艺为:壳聚糖微球在0.01%的戊二醛溶液中,60℃下震荡交联2 h,然后加入153 mU/g的β-葡萄糖苷酶,在pH6.0、30℃下震荡吸附16 h,固定化酶酶活回收率为74.26%。此工艺能有效提高橡胶籽及β-葡萄糖苷酶的利用率,使β-葡萄糖苷酶无需高度纯化即可实现良好的固定化效果,具有实际生产意义。

关键词：橡胶籽 β-葡萄糖苷酶壳聚糖戊二醛固定化

双溶剂冷冻结晶法分离橡胶籽油中α-亚麻酸工艺研究

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食品科技 2014年第7期39卷 233-237页

作者：雍梁敏王丽蓉刘石生热带生物资源教育部重点实验室海南大学食品学院海口570228

以橡胶籽油为原料,经皂化制得混合脂肪酸,采用双溶剂冷冻结晶法分离橡胶籽油中α-亚麻酸。通过正交实验确定了最佳的双溶剂冷冻结晶工艺条件为:以乙腈和丙酮为混合溶剂,乙腈:丙酮(v:v)为4:6,m(混合脂肪酸):v(乙腈与丙酮)=1:15,冷冻结晶... 详细信息

以橡胶籽油为原料,经皂化制得混合脂肪酸,采用双溶剂冷冻结晶法分离橡胶籽油中α-亚麻酸。通过正交实验确定了最佳的双溶剂冷冻结晶工艺条件为:以乙腈和丙酮为混合溶剂,乙腈:丙酮(v:v)为4:6,m(混合脂肪酸):v(乙腈与丙酮)=1:15,冷冻结晶时间为10 h,固液分离方式为-18℃、7000 r/min冷冻离心3 min。最佳条件下,橡胶籽油中α-亚麻酸的相对含量由16.32%提高到31.52%,总不饱和脂肪酸含量也达98.28%。

关键词：双溶剂冷冻结晶法分离橡胶籽油 α-亚麻酸

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固定化橡胶籽β-葡萄糖苷酶的制球工艺研究

食品科技 2014年第5期39卷 222-225页

作者：王丽蓉雍梁敏刘石生海南大学热带生物资源教育部重点实验室海南大学食品学院海口570228

将从橡胶籽中提取的β-葡萄糖苷酶采用戊二醛交联吸附的方法固定到壳聚糖微球上,在单因素实验基础上,以壳聚糖浓度、乙酸浓度及凝结液配比为自变量,酶活回收率为响应值,采用响应面法对制球工艺进行优化。最优制球工艺为:2.5%壳聚糖、2%... 详细信息

将从橡胶籽中提取的β-葡萄糖苷酶采用戊二醛交联吸附的方法固定到壳聚糖微球上,在单因素实验基础上,以壳聚糖浓度、乙酸浓度及凝结液配比为自变量,酶活回收率为响应值,采用响应面法对制球工艺进行优化。最优制球工艺为:2.5%壳聚糖、2%乙酸、NaOH浓度为7.5%、凝结液7.5%NaOH:95%乙醇(v/v)=1:1、静置时间为14 h,固定化酶酶活回收率为74.97%。

关键词：橡胶籽 β-葡萄糖苷酶壳聚糖固定化