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Science China Chemistry 2024年第2期67卷 542-550页

作者： Min Chen Longqing Yang Yuzhen Li Yinhe Qu Guihua Pan xiaoming feng Xiaohua Liu Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu610064China

A highly efficient asymmetric allylic alkylation of cyclic and acyclic carbon nucleophiles with vinyl epoxides has been developed,which exhibits good functional group compatibility,high atomic and step *** protocol utilizes a strategy of synergistic catalysis with a chiral N,N'-dioxide/Ni~Ⅱ complex and an achiral Pd~0 catalyst,generating a series of multisubstituted allylic alcohols with a quaternary carbon stereocenter in high yield and excellent regio-,Z/E-and enantioselectivity under mild *** transformations of the product demonstrate the potential utility of this protocol in the synthesis of allyl alcohol derivatives and natural product *** studies revealed that the N,N′-dioxide/metal complexes play an important role in controlling the Z/E-and *** density functional theory(DFT) calculations further demonstrated that multiple C–H···π interactions between the aromatic rings of the two substrates and the amide moiety in the ligand stabilized the dominant transition state.

关键词： asymmetric allylic alkylation synergistic catalysis vinyl epoxides allyl alcohol multiple weak interactions

Copper-catalyzed asymmetric dearomatizing amination of 2-naphthols:Csp^(2)–N coupling via 1,3-reductive elimination

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Science China Chemistry 2024年第8期67卷 2694-2700页

作者： Aying Yihuo Maoping Pu Zheng Tan Jibang Liao Jiuqi Tan Qi-Lin Zhou Xiaohua Liu xiaoming feng Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China Key Laboratory and Institute of Elemento-Organic Chemistry College of Chemistry Frontiers Science Centerfor New Organic MatterNankai UniversityTianjin300071China

An efficient catalytic asymmetric dearomatizing amination of 2-naphthols and phenols catalyzed by N,N′-dioxide-copper(I)complex as a chiral catalyst was presented.A variety of optically activeβ-naphthalenone compounds with a nitrogen-containing quaternary carbon stereocenter were obtained with high yield and enantioselectivity under mild reaction *** studies indicated that this Csp^(2)–N dearomatizing coupling proceeds via 1,3-reductive elimination of phenolate-Cu~Ⅲ-amino intermediate in five-membered ring transition *** origin of enantioselectivity has also been elucidated based on density functional theory calculations.

关键词： asymmetric catalysis amination dearomatization copper catalysis coupling reaction

Copper-catalyzed asymmetric dearomatizing amination of 2-naphthols: Csp–N coupling via 1,3-reductive elimination

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Science China Chemistry 2024年

作者： Aying Yihuo Maoping Pu Zheng Tan Jibang Liao Jiuqi Tan Qi-Lin Zhou Xiaohua Liu xiaoming feng Key Laboratory of Green Chemistry & Technology Ministry of Education College of Chemistry Sichuan University Key Laboratory and Institute of Elemento-Organic Chemistry College of Chemistry Frontiers Science Center for New Organic Matter Nankai University

An efficient catalytic asymmetric dearomatizing amination of 2-naphthols and phenols catalyzed by N,N′-dioxide-copper（I）complex as a chiral catalyst was presented. A variety of optically active β-naphthalenone compounds with a nitrogen-containing quaternary carbon stereocenter were obtained with high yield and enantioselectivity under mild reaction conditions. Mechanistic studies indicated that this Csp2–N dearomatizing coupling proceeds via 1,3-reductive elimination of phenolate-CuIII-amino intermediate in five-membered ring transition states. The origin of enantioselectivity has also been elucidated based on density functional theory calculations.

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颗粒增强铝基复合材料热等静压近净成形有限元模拟

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精密成形工程 2024年第4期16卷 1-9页

作者：冯效铭张峻凡王东肖伯律马宗义中国科学院金属研究所师昌绪先进材料创新中心沈阳110016 中国科学技术大学材料科学与工程学院沈阳110016

目的建立可靠的模拟方法,以更高效地预测颗粒增强铝基复合材料(PRAMC)粉末热等静压中的形状变化和不同部位致密度的差异,解决传统实验试错方法适用性差且费时费力的问题,满足批量应用的需求。方法以45%(体积分数)SiCp/6092Al复合材料为... 详细信息

目的建立可靠的模拟方法,以更高效地预测颗粒增强铝基复合材料(PRAMC)粉末热等静压中的形状变化和不同部位致密度的差异,解决传统实验试错方法适用性差且费时费力的问题,满足批量应用的需求。方法以45%(体积分数)SiCp/6092Al复合材料为研究对象,构建了能预测粉末热等静压成形过程的有限元模型。使用Gurson-Tvergard-Needleman(GTN)模型作为粉末本构模型,建立了粉末尺度的代表性体积单元(RVE)对GTN模型进行修正。结果通过对比GTN模型计算结果与实验结果,发现修正后的GTN模型能更准确地预测模型的最终变形尺寸,与修正前相比,相对误差降低了1.6%~2.9%。使用修正后的GTN模型对杯形回转体零件的热等静压成形过程进行预测,最终形状的计算结果与实验结果的相对误差仅为0.2%~3.1%,致密度分布的相对误差在0.5%以内。在探究包套厚度对热等静压过程的影响时发现,随着包套厚度的增大,热等静压过程中的屏蔽作用增强,内部粉体致密度下降。结论为PRAMC热等静压近终形制备的形状和致密度控制问题提供了有限元预测工具,辅助优化了热等静压工艺和包套设计,降低了颗粒增强铝基复合材料热等静压近净成形过程开发的试错成本。

关键词：颗粒增强铝基复合材料粉末冶金体积代表单元 GTN模型近净成形

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背包架电梯的安全钳不同布置位置的制动性能分析

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中国电梯 2024年第6期35卷 20-22页

作者：冯小明胡志刚巨立电梯股份有限公司江苏苏州215300

针对当前一些背包架结构的电梯存在的轿厢安全钳不能可靠制停问题进行了分析。首先介绍了背包架结构的电梯常用的滚轮导靴和安全钳,然后对安全钳位于轿架的上导靴位置附近和下导靴位置附近两种方案的动作过程逐步进行分析,找出安全钳动... 详细信息

针对当前一些背包架结构的电梯存在的轿厢安全钳不能可靠制停问题进行了分析。首先介绍了背包架结构的电梯常用的滚轮导靴和安全钳,然后对安全钳位于轿架的上导靴位置附近和下导靴位置附近两种方案的动作过程逐步进行分析,找出安全钳动作后不能夹紧导轨的原因,并提出解决方案。

关键词：背包架结构的电梯导靴安全钳布置位置制动性能

Catalytic asymmetric synthesis of chiral azo compounds via interrupted Japp-Klingemann reaction with aryldiazonium salts

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Science China Chemistry 2022年第3期65卷 546-553页

作者： Yan Wang Aying Yihuo Lifeng Wang Shunxi Dong xiaoming feng Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China

Asymmetric synthesis of enantioenriched azo compounds bearing tetrasubstituted stereocenter was achieved through chiral N,N′-dioxide/metal Lewis acid promoted interrupted Japp-Klingemann reaction of aryldiazonium tetrafluoroborate salts with nucleophiles under mild conditions. This protocol features wide substrate scope and good functional group ***-containing chiral azo compounds were stable enough in Japp-Klingemann reaction condition. The key to success of the reaction was the employment of metal salt/N,N′-dioxide ligand and the dual-task roles of the base. Moreover, the X-ray crystal structure of Ni(II)/N,N′-dioxide/substrate complex confirmed that the substrate was activated by bidentate coordination, which shed light on the origin of chiral control of the reaction.

关键词： asymmetric synthesis Japp-Klingemann reaction chiral azo compounds aryldiazonium salts N-electrophile

提钒尾渣与赤泥共处置过程中铬硫元素的分配行为

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钢铁钒钛 2024年第3期45卷 101-106页

作者：王春会郁健冯晓明张延玲张帅北京科技大学绿色低碳钢铁冶金全国重点实验室北京100083 北京北科环境工程有限公司北京100083 建龙钢铁控股有限公司北京100070

钒渣钠化焙烧-水浸提钒过程会产生含有30%~40%Cr_(2)O_(3)的提钒尾渣,形成年堆积百万吨固废。通过加入高铁赤泥协同还原提钒尾渣,赤泥中的Fe_(2)O_(3)在低于铬氧化物初始还原温度下已经被C还原,促使铬还原反应快速进行,从而提升Cr的回... 详细信息

钒渣钠化焙烧-水浸提钒过程会产生含有30%~40%Cr_(2)O_(3)的提钒尾渣,形成年堆积百万吨固废。通过加入高铁赤泥协同还原提钒尾渣,赤泥中的Fe_(2)O_(3)在低于铬氧化物初始还原温度下已经被C还原,促使铬还原反应快速进行,从而提升Cr的回收效率。使用FactSage热力学软件对整个反应体系进行模拟,计算了原料铬铁比、炉渣碱度和配C/Si量对铬、硫元素分配行为的影响,得到原料适宜的铬铁比是0.18,炉渣碱度是1.8,配C量n_(C/O)=1.1,配Si量n_(Si/O)=0.2。该研究为含铬提钒尾渣和高铁赤泥的资源化处理和增值化应用提供了一种新的可行性方案。

关键词：提钒尾渣高铁赤泥协同还原铬回收脱硫热力学计算

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基于Fluent的非光滑表面减阻仿真实验

实验技术与管理 2024年第1期41卷 85-90页

作者：冯晓明朱东坡颜兵兵陈光田桂中江苏科技大学机械工程学院江苏镇江212100 佳木斯大学机械工程学院黑龙江佳木斯154007 江苏科技大学教务处江苏镇江212100

该文基于有限元法构建了一套可用于非光滑表面减阻仿真的实验方案。将在ICEM中划分的非光滑表面模型网格导入ANSYS中的Fluent模块进行仿真计算,通过对比分析不同速度、不同展向间距圆锥微结构的减阻率评估减阻效果,并利用可视化功能观... 详细信息

该文基于有限元法构建了一套可用于非光滑表面减阻仿真的实验方案。将在ICEM中划分的非光滑表面模型网格导入ANSYS中的Fluent模块进行仿真计算,通过对比分析不同速度、不同展向间距圆锥微结构的减阻率评估减阻效果,并利用可视化功能观测速度、压力和湍动能云图,探究了由圆锥微结构构成的非光滑表面减阻规律,为减阻性能方面研究提供了一种新的思路。

关键词：非光滑表面圆锥微结构减阻 Fluent 实验教学

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C–H alkylation of pyridines with olefins catalyzed by imidazolin-2-iminato-ligated rare-earth alkyl complexes

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Science China Chemistry 2023年第6期66卷 1804-1813页

作者： Dawei Li Lichao Ning Qiliang Luo Shiyu Wang xiaoming feng Shunxi Dong Key Laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China

An array of rare-earth bis(aminobenzyl)complexes supported by imidazolin-2-iminato ligands were synthesized and structurally *** complexes showed high activity towards ortho-Csp^(2)–H alkylation of 2-alkylpyridines and benzylic Csp^(3)–H alkylation of 2,6-dialkylpyridines with alkenes.A wide range of alkyl or aryl substituted olefin substrates are compatible,providing an atom-economical route to linear or branched alkylated pyridine derivatives in moderate to high yields(45 examples,up to 99%yield).The primary study suggested that the asymmetric version of Csp^(3)–H alkylation of 2,4,6-collidine with allylbenzene was feasible with chiral imidazolin-2-iminato-ligated scandium(III)complexes,and good yield with moderate enantioselectivity was obtained(84%yield,84:16 er).Mechanistic investigations including kinetic isotope effect(KIE)experiments and density functional theory(DFT)calculations shed light on the catalytic cycle and the origin of enantiocontrol.

关键词： pyridine C-H functionalization rare-earth imidazolin-2-iminato ligand asymmetric catalysis

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超低钠小原晶α氧化铝的陶瓷烧结性能研究

当代化工研究 2024年第1期 32-34页

作者：秦念勇齐波冯晓明中铝山东有限公司山东255051

本文详细研究了低钠小原晶α氧化铝的原晶粒度、Na_(2) O含量、粉体粒度分布以及烧结温度对陶瓷烧结性能的影响。研究结果表明原晶粒度越小、Na_(2) O含量越低、粉体粒度越细,所得氧化铝陶瓷越致密。以国内某公司的超低钠小原晶α氧化铝... 详细信息

本文详细研究了低钠小原晶α氧化铝的原晶粒度、Na_(2) O含量、粉体粒度分布以及烧结温度对陶瓷烧结性能的影响。研究结果表明原晶粒度越小、Na_(2) O含量越低、粉体粒度越细,所得氧化铝陶瓷越致密。以国内某公司的超低钠小原晶α氧化铝(Na_(2) O含量0.02%,原晶粒度0.2~0.5μm)为原料,将粉体磨至接近原晶粒度,然后通过造粒、干压所得生坯在1600~1620℃下烧结,陶瓷试块烧结密度达到理论烧结密度的99.5%以上,展现出优良的陶瓷烧结性能。

关键词：超低钠小原晶α氧化铝陶瓷烧结性能烧结密度