检索结果-南通市图书馆

Aromatic and olefinic C–H alkenylation by catalysis with spirocyclic NHC Ru(Ⅳ) pincer complex

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第10期66卷 2791-2796页

作者： Heng Cai Yong-Qiang Tu Ka Lu Qi-Long Chen Fu-Min Zhang Xiao-Ming Zhang yuan-jiang pan Zhi-Bo Yan State Key Laboratory of Applied Organic Chemistry&College of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou 730000China School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Jiao Tong UniversityShanghai 200240China Department of Chemistry Zhejiang UniversityHangzhou 310027China

Catalyst innovation lies at the heart of transition-metal-catalyzed reaction development. In this article, we have explored the C(sp2)–H alkenylation activity with novel spirocyclic N-heterocyclic carbene(NHC)-based cyclometalated ruthenium pincer catalyst system, SNRu-X. After screening catalyst and condition, a high valent Ru(Ⅳ) dioxide(X = O_(2)) species has demonstrated superior reactivity in the catalytic alkenylation of aromatic and olefinic C–H bonds with unactivated alkenyl bromides and triflates. This reaction has achieved the easy construction of a wide range of(hetero)aromatic alkenes and dienes, in good to excellent yields with exclusive selectivity. Preliminary mechanistic studies indicate that this reaction may proceed through a single electron transfer(SET) triggered oxidative addition, by doing so, providing valuable complementary to classical alkenylation reactions that are dependent on activated alkenyl precursors.

关键词： transitionmetal catalysis spirocyclic NHC-Ru pincer catalyst C-H alkenylation single electron transfer pathway unactivated alkenyl bromides and triflates

Preliminary studies on the chemical characterization and antioxidant properties of acidic polysaccharides from Sargassum fusiforme

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第9期9卷 721-727页

作者： Jing ZHOU, Nan HU, Ya-lin WU, yuan-jiang pan, Cui-rong SUN (Department of Chemistry, Zhejiang University, Hangzhou 310027, China) Department of Chemistry Zhejiang University Hangzhou 310027 China.

In order to investigate the antioxidant properties of the polysaccharides from the brown alga Sargassum fusiforme, the crude polysaccharides from S. fusiforme (SFPS) were extracted in hot water, and the lipid peroxidation inhibition assay exhibited that SFPS possessed a potential antioxidant activity. Hence, two purely polymeric fractions, SFPS-1 and SFPS-2 were isolated by the column of DEAE (2-diethylaminoethanol)-Sepharose Fast Flow, with their molecular weights of 51.4 and 30.3 kDa determined by high performance gel permeation chromatography (HPGPC). They were preliminarily characterized using chemical analysis in combination of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and found to contain large amounts of uronic acids and β-glycosidical linkages. The antioxidant activities of these two SFPS fractions were evaluated using superoxide and hydroxyl radical-scavenging assays. The results show that the antioxidant ability of SFPS-2 was higher than that of SFPS-1, probably correlating with the molecular weight and uronic acid content.

关键词： Sargassum fusiforme Polysaccharide Antioxidant activity Uronic acid Molecular weight

New Diterpenoid Alkaloids from Delphinium Souliei Franch

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第5期10卷 395-396页

作者： Lan HE yuan jiang pan Xuan pan Bo Gang LI Yao Zu CHEN(Department of Chemistry. Beijing Normal University. Beijing 100085 Department of Chemistry. Zhejiang University. Hangzhou 310027Department of Pharmcy. Lanzhou Medical College. Lanzhou 730000The Che Department of Chemistry Beijing Normal University Beijing 100085 China Department of Chemistry Zhejiang University Hangzhou 310027 China Department of Pharmcy Lanzhou Medical College Lanzhou 730000 China Chengdu Institute of Biology Chinese Academy of Sciences Chengdu 610041 China

Continuing investigation of Delphinium souliei Franch yielded two minor new diterpenoid alkaloids--souline E(1) and souline F(2), their structures were determined on the basis of spectroscopic evidences.

关键词： Delphinium souliei new deterpenoid alkaloids souline E and F spectral data

A Minor New Diterpenoid Alkaloids from the Roots of Delphinium Souliei Franch

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第12期10卷 0-0页

作者： Lan HE yuan jiang pan Bo Gang LI Yao Zu CHEN(1Department of Chemistry, Beijing Normal University, Beijing, 100085)(2 Department of Chemistry, Zhejiang University, Hangzhou 310027)(3The Chengdu institute of Biology, Chinese Academy of Sciences, Chengdu Department of Chemistry Beijing Normal University Beijing 100085 China Department of Chemistry Zhejiang University Hangzhou 310027 China Chengdu Institute of Biology Chinese Academy of Sciences Chengdu 610041 China

A minor new diterpenoid alkaloid, soulidine, was isolated from the roots of DelphiniumSouliei Franch, its structure was established on the basis of spectral evidences.

关键词： DeIPhinium souliei new deterpenoid alkaloid soulidine spectral data.

Scavenging activity and mechanism study of ferulic acid against reactive carbonyl species acrolein

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2019年第11期20卷 868-876页

作者： Zhi-hao TAO Chang LI Xiao-fei XU yuan-jiang pan Department of Chemistry Zhejiang UniversityHangzhou 310027China College of Life Sciences Zhejiang Chinese Medical UniversityHangzhou 310053China

Acrolein,known as one of the most common reactive carbonyl species,is a toxic small molecule affecting human health in daily *** study is focused on the scavenging abilities and mechanism of ferulic acid and some other phenolic acids against *** the 13 phenolic compounds investigated,ferulic acid was found to have the highest efficiency in scavenging acrolein under physiological *** acid remained at(3.04±1.89)%and acrolein remained at(29.51±4.44)%after being incubated with each other for 24 *** molecular mechanism of the detoxifying process was also *** products,namely 2-methoxy-4-vinyIphenol(product 21)and 5-(4-hydroxy-3-methoxyphenyl)pent-4-enal(product 22),were identified though nuclear magnetic resonanee(NMR)and gas chromatography-mass spectrometry(GC-MS),after the scavenging *** acid showed significant activity in scavenging acrolein under physiological *** study indicates a new method for inhibiting damage from acrolein.

关键词： Acrolein Reactive carbonyl species Ferulic acid Cytotoxicity Oxidative stress

Detection and Quantification of Water-Soluble Inorganic Chlorine,Bromine and Iodine by MALDI-MS

在线全文

学校读者我要写书评

暂无评论

Journal of Analysis and Testing 2022年第4期6卷 419-423页

作者： Yi Tong Zheng-Zheng Liu Jia-Feng Lu Hai-Yan Zhang Ke-Qiang Shi Guan-Ru Chen Ya-Qin Liu Hong-Ru Feng yuan-jiang pan Department of Chemistry Zhejiang UniversityHangzhou310027China Zhejiang Key Laboratory of Ecological and Environmental Monitoring Forewarning and Quality ControlZhejiang Ecological and Environmental Monitoring CenterHangzhou310012China School of Environment Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou310000China

Halogens are elements in soil and water that occur as organic and inorganic *** have shown that inorganic halogens are closely related to animal and plant ***-assisted laser desorption/ionization mass spectrometry(MALDI-MS)can achieve high-throughput and rapid analysis,which is also an essential characteristic in some environmental ***,there is currently no report on MALDI-MS analysis for water-soluble inorganic halogen *** this study,we aimed to develop a reliable and reproductive method to detect inorganic halogens in soil and water by *** on sinapic acid(SA)and silver trifluoromethanesulfonate(SA/AgOTf)as the matrix in negative-ion mode,MALDI-MS showed excellent MS signals related to *** the optimum conditions,the method achieved satisfactory linearity(R^(2)>0.99)and repeatability(RSD<18%).The LODs for Cl^(−),Br^(−)and I^(−)were 0.76,0.11 and 0.10μg/mL,*** concentration of inorganic halogens from 24 samples was successfully determined by *** summary,an innovative method was developed for the analysis of inorganic halogens by MALDI-MS using a novel SA/AgOTf matrix,extending the application of MALDI-MS in inorganic compounds.

关键词： MALDI-MS Water-soluble halogen Quantification Soil Water

The 1:2 Complex of Piperazine with Some Phenols:Hydrogen Bonding Pattern Involved in Transition States in Solution

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2000年第2期11卷 105-106页

作者： Zhi Min JIN1 yuan jiang pan1 Si Hua SHANG2 Duan Jun XU1 yuan Zhi XU1 (1 Department of Chemistry, Zhejiang University, Hangzhou 310027 2Zhejiang Entry-exit Inspection and Quarantine Bureau of the People’s Republic of China, Hangzhou 310012) Department of Chemistry Zhejiang University Hangzhou 310027 China Zhejiang Entry-exit Inspection Q. Hangzhou 310012 China

A novel model for the 1: 2 complex of piperazine with some phenols in solution is established and verified. In CDCl3 solution, one piperazine molecule is tied to two phenol molecules by hydrogen bonds of O-H---N and N-H---O. And the protons of >NH and -OH groups exchange quickly and simultaneously between the atoms of phenol oxygen and piperazine nitrogen.

关键词： piperazine phenol hydrogen bond (HNMR)-H-1 ESI-MS

A NEW DITERPENOID ALKALOID FROM DELPHININUM CAERULEUM

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1996年第2期7卷 139-140页

作者： YaN,WANG yuan jiang pan Shao Nong CHEN Yao Zu CHEN(State Key Laboratory of Applied Organic Chemistry and Department of Chemistry. Lanzhou University, Lanzhou 730000)(Departwent of Chemistry, Zhejiang University,Hangzhou 310027) State Key Lab. of Appl. Organ. Chem. Department of Chemistry Lanzhou University Lanzhou 730000 China Department of Chemistry Zhejiang University Hangzhou 310027 China

A new minor diterpenoid alkaloid containing a C(19)=N-azomethine group, caerunine (1) was isolated from Delphinium caeruleum ***, its structure was determined by spectral data.

关键词：

Optimal Scheduling of an Independent Electro-Hydrogen System with Hybrid Energy Storage Using a Multi-Objective Standardization Fusion Method

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2025年第1期122卷 63-84页

作者： SuliangMa ZeqingMeng Mingxuan Chen yuan jiang School of Electrical and Control Engineering North China University of TechnologyBeijing100144China ChinaThree Gorges Technology Co. Ltd.Beijing100032China School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing100083China

In the independent electro-hydrogen system(IEHS)with hybrid energy storage(HESS),achieving optimal scheduling is ***,it presents a challenge due to the significant deviations in values ofmultiple optimization objective functions caused by their physical *** deviations seriously affect the scheduling process.A novel standardization fusion method has been established to address this issue by analyzing the variation process of each objective function’s *** optimal scheduling results of IEHS with HESS indicate that the economy and overall energy loss can be improved 2–3 times under different optimization *** proposed method better balances all optimization objective functions and reduces the impact of their *** the cost of BESS decreases by approximately 30%,its participation deepens by about 1 ***,if the price of the electrolyzer is less than 15￥/kWh or if the cost of the fuel cell drops below 4￥/kWh,their participation will increase *** study aims to provide a more reasonable approach to solving multi-objective optimization problems.

关键词： Electro-hydrogen system multi-objective optimization standardization method hybrid energy storage system