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Studies on the Relationship between the Helical Structure and Optical Activity of Some Chiral Cyclic Esters Ⅱ

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Chinese Chemical Letters 1997年第2期8卷 141-144页

作者： Ai Hua NIE xiu Lin ye Qi Yi XING(Department of Chemistry,Pcking University,Beijing 100871) Department of Chemistry Peking University Beijing 100871 China

A method for the analysis of the relationship between the helical structure and optical activity was proposed by the study of the conformations and X-ray diffraction structures of some cyclic esters prepared by esterification of L-(-)-2.3-O-methylidene threitol and L-(+)-2,3-O-isopropplidene threitol with alkanedioyl dichlorides and o-,m-,and p-phthaloyl dichlorides.

关键词： Activity Cl Studies on the Relationship between the Helical Structure and Optical Activity of Some Chiral Cyclic Esters

Studies on the Synthesis of Sesamin-Group Lignans Ⅷ. A Simplified Sythesis of 2-Aryl-4-phenyloxazoles and 2-Alkyl-4-phenyloxazoles

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Chinese Chemical Letters 1997年第8期8卷 689-690页

作者： Xiao Ping NIE Zhen Qiang WANG xiu Lin ye(Department of Chemistry,Peking University, Beijing, 100871) Department of Chemistry Peking University Beijing 100871 China

The reaction of phenacyl benzoate derivatives with acetamide at about 140°in the presence of BF3 catalyst gave 2-aryl-4-phenyloxazoles. This method can be applied to the preparation of 2-alkyl-4-phenyloxazoles as well.

关键词： Studies on the Synthesis of Sesamin-Group Lignans A Simplified Sythesis of 2-Aryl-4-phenyloxazoles and 2-Alkyl-4-phenyloxazoles

STUDIES　ON　THE　SYNTHESIS　OF　SESAMIN－GROUP　LIGNANS　V．　A　CONVENIENT　METHOD　FOR　THE　PREPARATION　OF　2－ARYL－4－PHENYLOXAZOLES

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Chinese Chemical Letters 1995年第10期6卷 843-846页

作者： Bing Zi CHEN Jian PEI Jie WU xiu Lin ye (Department of Chemistry, Peking Universitys Beijing 100871) Beijing Univ Dept Chem Beijing 100871 Peoples R China

Nine 2-axyL4-phenyloxazoles ale prepared fromphenacyl benzoates and acetandde in boiling xylene under the actionof boron fluoride as catalyst. By this improved method the oxazoles areobtained as single products with y...

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STUDIES　ON　THE　RELATIONSHIP　BETWEEN　THE　HELICAL　STRUCTURE　AND　OPTICAL　ACTIVITIES　OF　SOME　CHIRAL　CYCLICESTERS　Ⅰ

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Chinese Chemical Letters 1996年第7期7卷 627-630页

作者： Bing DENG(Department of Chemistry,ShanXi University,TaiYuan,030006)xiu Lin ye and Qi Yi XING(Department of Chemistry,Peking University,Beijing, 100871) Department of Chemistry Shanxi University Taiyuan 030006 Department of Chemistry Peking University Beijing 100871

A method to analyze the relationship between the helical structure and optivity was proposedby the study of the conformations and X-ray structures of some cyclic esters possessing a C2-synimetry elementwhich were prep...

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漳泽水库优化汛限水位必要性可行性分析

山西水利科技 2022年第1期 33-35,41页

作者：叶秀山西漳泽水库管理有限公司山西长治046021

介绍了漳泽水库优化汛限水位的计算方法,从可操作性和蓄水条件两方面论述了优化汛限水位的必要性,通过非主汛期发生历史暴雨或设计洪水时优化汛限水位的安全性分析及“台阶式汛限水位”与优化汛限水位的风险对比,论证了漳泽水库优化汛... 详细信息

介绍了漳泽水库优化汛限水位的计算方法,从可操作性和蓄水条件两方面论述了优化汛限水位的必要性,通过非主汛期发生历史暴雨或设计洪水时优化汛限水位的安全性分析及“台阶式汛限水位”与优化汛限水位的风险对比,论证了漳泽水库优化汛限水位的可行性。

关键词：优化汛限水位安全性可行性

Colorimetric Determination of Chloridion in Domestic Water Based on the Wavelength Shift of CsPbBr_(3) Perovskite Nanocrystals via Halide Exchange

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Journal of Analysis and Testing 2021年第1期5卷 3-10页

作者： Guo-Bin Huang Zhi-Yong Guo Ting-xiu ye Chen Zhang Yan-Mei Zhou Qiu-Hong Yao Xi Chen Institute of Analytical Technology and Smart Instruments and Colleague of Environment and Public Healthy Xiamen Huaxia UniversityXiamen 361024China College of Pharmacy Xiamen Medical CollegeXiamen 361023China College of Chemistry Chemical Engineering and EnvironmentMinnan Normal UniversityZhangzhou 363000China Xiamen Key Laboratory of Food and Drug Safety Xiamen Huaxia UniversityXiamen 361005China State Key Laboratory of Marine Environmental Science Xiamen UniversityXiamen 361024China

Cubic phase CsPbBr_(3)perovskite nanocrystals(PNCs)was prepared by a high-temperature hot-injection *** high photoluminescence quantum yield(PLQY)of as-prepared CsPbBr_(3)PNCs was 87%,which can be used for the determination of chloridion in domestic water samples based on their wavelength-shift characteristics via halide *** proposal approach for the determination of chloridion reveals a linear correlation ranged from 10 to 200μM of the chloridion concentration and the wavelength shift of CsPbBr_(3)PNCs with a correlation coe fficient of R^(2)=*** as-mentioned method reveals neglectable responses towards those co-existing ions in the water aside from chloridion,due to the quick exchange between Cl and Br and the outstanding color change caused by wavelength *** strategy has been applied to the determination of chloridion in water samples with the recoveries of 98.9–104.2%and the limit of detection(LOD)of 4μ*** results show that the suggested approach is promising for the development of novel fluorescence detection for chloridion in water.

关键词： CsPbBr_(3) Perovskite nanocrystals Wavelength shift Chloridion

Cosmetics use-related adverse events

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Chinese Medical Journal 2019年第17期132卷 2135-2136页

作者： Su-Lian Yang Yue Zheng Yun-Qing Zhang Cong-xiu ye Jin-Ling Yi Yu-Fang Liu Wei Lai Department of Dermatology and Venereology The Third Affiliated Hospital Sun Yat-sen University Guangzhou Guangdong 510630 China

To the Editor: Cosmetics (non-prescription skin care products) use-induced adverse events could present as skin erythema, papules, pruritus, dryness, desquamation, and abnormal discoloration. Non-medicated cosmetics use is more and more common in the China, but little is known about the characteristics of cosmetic-related adverse events.

关键词： pruritus desquamation erythema

电子商务与县域地区人口规模——基于面板PSM-DID和中介效应模型的实证研究

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财经问题研究 2022年第8期 122-128,F0003页

作者：王元正叶秀敏中国社会科学院大学商学院北京100732 中国社会科学院数量经济与技术经济研究所北京100732

目前,我国乡村振兴战略面临着农村劳动力短缺的问题,而电子商务可以为解决这一难题提供一个崭新而有效的思路。本文以2006—2019年1178个县域地区为样本,以淘宝村代表电子商务对县域地区的冲击,运用改进后的面板PSM-DID方法及中介效用... 详细信息

目前,我国乡村振兴战略面临着农村劳动力短缺的问题,而电子商务可以为解决这一难题提供一个崭新而有效的思路。本文以2006—2019年1178个县域地区为样本,以淘宝村代表电子商务对县域地区的冲击,运用改进后的面板PSM-DID方法及中介效用模型检验了电子商务对县域地区人口规模的影响。实证结果表明,电子商务有助于县域地区的人口规模增长。中介效应检验表明,电子商务能够促进农产品贸易规模扩张,发挥对服务业和流通业的乘数效应,进而促进人口规模增加。进一步地,异质性检验结果发现,相较于以往的土地政策,电子商务对于中西部地区人口的促进作用更加明显。最后,针对电子商务发展的前提与局限,本文提出了完善基础建设、建立现代化流通体系、促进农业信息化发展等有助于乡村振兴的建议。

关键词：电子商务县域地区人口规模乡村振兴中介效应面板PSM-DID

维普期刊数据库博看期刊

The Synthesis of 4-Arylcarbonyl-3-methoxycarbonyl-2-phenylfurans by Friedel-Crafts Acylation Reactions

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Chinese Chemical Letters 2000年第1期11卷 11-14页

作者： Shrong Shi LIN Jun Hua YU Jian Mei WANG Bo YANG xiu Lin ye (Department of Chemistry. Peking University, Beijing 100871) Department of Chemistry Peking University Beijing 100871 China

Keto esters 8, 4-arylcarbonyl-3-methoxycarbonyl-2-phenylfurans, potential precursors of the synthesis of furofuran lignans, were obtained from dimethyl 2-phenylfuran-3,4-dicarboxylate 2. Diester 2 was selectively hydrolyzed to monoacid 6 followed by converting to its acid chloride 7. Friedel-Crafts acylation reactions of 7 with aromatic compounds afforded keto esters 8. The geometric structures of 8 and its precursors were elucidated and verified by NMR spectra.

关键词： Friedel-Crafts acylation selective mono hydrolysis furofuran lignan