检索结果-南通市图书馆

The density of surface ligands regulates the luminescence of thiolated gold nanoclusters and their metal ion response

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第8期32卷 2390-2394页

作者： Jie Xu Juanmin Li Wencheng Zhong Mengyao Wen Gleb Sukhorukov Li Shang State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene(NPU)Xi'an 710072China NPU-QMUL Joint Research Institute of Advanced Materials and Structures(JRI-AMAS) Northwestern Polytechnical UniversityXi'an 710072China Materials Research Institute School of Engineering and Materials ScienceQueen Mary University of LondonLondon E14NSUnited Kingdom

The fascinating luminescence properties of gold nanoclusters(AuNCs) have drawn considerable research interests,and been widely harnessed for a wide range of ***,a fundamental understanding towards ligand density’s role in the luminescence properties of these ultrasmall AuNCs remains unclear *** this communication,through systematic investigation of surface chemistries of glutathione-protected Au NCs(GSH-Au NCs) with diffe rent density of GSH as well as other thiolates,it is discovered that the density of surface ligands can significantly regulate the luminescence properties of *** lifetime spectroscopy and X-ray photoelectron spectroscopy showed that AuNCs with a higher density of electron-rich ligands facilitate their luminescence ***,differences in the surface coverage of AuNCs can also affect their interactions with foreign species,as illustrated by significantly different fluorescence quenching capability of GSH-AuNCs with different ligand density towards Hg^(2+).This study provides new insight into the intriguing luminescence properties of metal NCs,which is hoped to stimulate further research on the design of metal NCs with strong luminescence and sensitive/specific responses for promising optoelectronic,sensing and imaging applications.

关键词： Gold nanoclusters Luminescence enhancement Ligand density Thermal treatment metal ion

A review of covalent organic frameworks for metal ion fluorescence sensing

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第8期35卷 74-83页

作者： Deshuai Zhen Chunlin Liu Qiuhui Deng Shaoqi Zhang Ningman Yuan Le Li Yu Liu Hunan Key Laboratory of Typical Environment Pollution and Health Hazards School of Public HealthHengyang Medical SchoolUniversity of South ChinaHengyang 421001China State Key Laboratory of Chemo/Biosensing and Chemometrics School of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China

The concentration of metallic elements is closely associated with overall ***,the discharge of untreated industrial wastewater can lead to metal-containing pollutants entering the human body through the food chain,disrupting the organism’s homeostasis and posing a risk to human ***-valent organic framework materials(COFs)have emerged as a novel porous material for detecting or adsorbing metal ions due to their unique pore structure,topological structure and flexible *** paper summarizes the role,toxicity,and sources of metal ions related to human health,as well as the design,synthesis and performance of COFs fluorescent materials for detecting these *** inter-action mechanism of different fluorescent COFs and metal ions are ***,the remaining challenges and prospects of COFs fluorescence sensors are *** believe this review will be useful in directing the development of fluorescent COFs towards metal ions.

关键词： Covalent organic frameworks metal ion Fluorescence Sensing Toxicity

metal ion Production with RIKEN 18GHz-ECRIS

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2007年第S1期31卷 97-100页

作者： M.Kidera T.Nakagawa T.Kageyama Y.Higurashi H.Haba T.Aihara T.Ohki K.Kobayashi A.Goto Y.Yano Nishina Center for Accelerator Based Science RIKENHirosawa2-1WakoSaitama 351-0198Japan SHI Acclcrator Service Ltd. Kitashinagawa5-9-11ShinagawaTokyo 141-8686Japan

At RIKEN,three ECR ion sources(10GHz ECRIS,18GHz ECRIS and liquid He-free SC-ECRIS) are operated as external ion sources of heavy ion *** the last year,multi-charged uranium ion beam was produced from 18GHz ECRIS by using UF_6 and the ^(238)U ion was successfully accelerated by the accelerator complex which consists of the RFQ linear accelerator,RIKEN heavy ion linear accelerator(RILAC)and RIKEN ring cyclotron accelerator(RRC).The typical beam intensity of^(238)U^(14+) was about 2pμA on faraday cup after analysing magnet.^(70)Zn beam was still supplied for the new super-heavy element search experiment with insertion *** beam of^(70)Zn^(16+) was produced for long term(～43 days)without vacuum break and remarkably low material consumption rate(～100μgr/h).We already supplied Zn beam longer than 200 days for this experiment.^(48)Ca ion was also produced by insertion method using^(48)CaO rod for the nuclear physics *** this contribution,we will present ion source parameter and techniques for production of each of the metal ions.

关键词： ECRIS metal ion ^(238)Su ^(70)Zn ^(48)Ca

Determination of heavy metal ion in landfill leachate with solvent extracting ＆ fluorescence quenching method

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Science and Engineering 2008年第10期2卷 24-29,79页

作者： YANG Ji-dong Department of Chemistry and Environment Science Yangtze Normal University Chongqing 408100 China

Add the masking agent and biscyclohexanoneoxalyldihydraone into the diluted clarificd liquid of the landfill leachate which was treatmented by digestion and centrifugal filtration to complexate all heavy metal ion in the trcatmented liquid, and extracted using CHCl3 many time, then it were demasking and decomposing respectively, and adjusted different pH and formed Me^n＋-PAN coordination compound when these metal ion reaction with PAN. The Fluoresence quenching of Rh6G （λex/λem=543mn/558nm） when the metal ion coordination compound was add into the Rh6G solution step by step, the quenching intensity was directly proportional to the concentration of the metal ion in the certain range. So a new method of fast and simple for determination of trace metal ion in landfill lcachate was established to determine metal ion in sample of different landfill leachate in Three Gorge Water Reservoir, and comparison the classic assay method with satisfactory results.

关键词： landfill leachate metal ion rhodamine 6G fluorescence quenching method 1- (2-pyridine-eazo)-2naphthol

Inhibition of cysteine protease papain by metal ions and polysulfide complexes,especially mercuric ion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Chinese Pharmaceutical Sciences 2007年第1期16卷 1-8页

作者：姜军杨晓达王夔北京大学药学院化学生物学系北京100083

Aim Cysteine proteases are closely associated with many human and non-human pathological processes and are potential targets for metal ions especially Hg^2＋ and the related species. In the present work, on the basis of to the general study on the effects of some metal ions on the activity of papain, a well-known representative of cysteine protease family, the inhibitory effects of Hg^2＋ and polysulfide complexes were studied. Results All the metal ions tested （Hg^2＋, Cu^2＋, Ag^＋, Au^3＋, Zn^2＋, Cd^2＋, Fe^3＋, Mn^2＋, Pb^2＋, Yb^3＋） inhibit the activity of papain anda good correlation between the inhibitory potency and softness-and-hardness was observed. Among the metals, Hg^2＋ was shown to be a potent inhibitor of papain with a Kiof 2 × 10^-7 mol·L^-1 among. Excessive amounts of glutathione and cysteine could reactivate the enzyme activity of papain deactivated by Hg^2＋. These evidences supported that Hg^2＋ might bind to the catalytic site of papain. Interestingly, Hg （Ⅱ） polysulfide complexes were for the first time found to inhibit papain with a Ki of 7 × 10^-6 mol·L^-1, whose potency is close to a well known mercury compound, thimerosal （Ki=2.7 × 10^-6）. In addition, Hg （Ⅱ） polysulfide complexes exhibit good permeability （ 1.9 × 10-5 cm· s^-1） to caco-2 monolayer. Conclusion These results suggested that mercury polysulfide complexes might be potential bioactive species in the interaction with cysteine proteases and other- SH-content proteins, providing a new clue to understand the mechanism of the toxicological and pharmacological actions of cinnabar and other insoluble mercury compounds.

关键词： metal ion Papain Cysteine protease Mercury metal polysulfide complex

The research on the adsorption effect on metal ions by immobilized marine algae

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2006年第2期25卷 153-158页

作者： WANG Xian QIU Haiyuan CAI Zhenzhen CHEN Lidan ZHENG Shenghua HUANG Zhiwei College of Oceanogrophy and Environmental Science Xiamen UniversityXiamen 361005China

The process of adsorption of Cu^2+ Cd^2+ by immobilized marine algae was investigated, it can be noted from the results that, the process for biosorption of heavy metals (copper, cadmium) by immobilized Laminaria japonica can be described by the Banerm model. According to the model, the adsorption rate constant calculated was 0.107 8 and 0.030 28 min^-1 for Cu^2+ and Cd^2+ respectively. The experimental biosorption equilibrium data for Cu^2+ and Cd^2+ were in good agreement with those calculated by the Langmuir model. The maximum uptake capacity calculated was 83.3 and 112.4 mg/g for Cu^2+ and Cd^2+ according to the Langmuir model, respectively. The appetency of Laminaria japonica to Cu^2+ was better than Cd^2+.

关键词： marine algae desorption effect metal ion immobilization

Studies on Synthesis of a Cycloheptapeptide and Effects of Different metal ions on the Cyclization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2002年第11期20卷 1347-1353,1131页

作者：刘勉叶蕴华 Key Laboratory of Bioorganic Chemistry and Molecular Engineering Ministry of Education Department of Chemistry Peking University Beijing 100871 China Email: Yim-Hua Ye (yhye@***)

A cyclic heptapeptide, c(Gly-Ile-Pro-Tyr-Ile-Ala-Ala), which was isolated and identified from Stellaria yumumensis French (M), was synthesized by solution method for the first time. Protected heptapeptide Z-Gly-Ile-Pro-Tyr-Ile-Ala-Ala-OBzl was synthesized with 3-(diethoxy-phosphoryloxy)-l,2,3-benzotriazin-4(3H)-one (DEPBT) as a coupling reagent. After deprotection of benzyl and benzyloxycarbonyl groups, a free linear heptapeptide H-Gly-Ile-Pro-Tyr-Ile-Ala-Ala-OH was cyclized in DMF (2 × 10?3 mol/L) in the presence of nine different metal ions, i. e., Li+, Na+, K+, Cs+, Mg2+, Ca2+, Bai2+, Nr2+ and Cr5+ respectively, using DEPBT as a coupling reagent. Univalent metal ion Cs+ enhanced both the cyclization yield and cyclization rate of H-Gly-De-Pro-Tyr-Ile-Ala-AlaOH, while some bivalent metal ions, such as Mg2+, Ca2+ and Ni2+ decreased the yields of c (Gly-Ile-Pro-Tyr-De-Ala-Ala) drastically. Trivalent metal ion Cr3+ even inhibited the cyclization reaction completely.

关键词： linear heptapeptide cyclic heptapeptide DEPBT metal ion cyclization

Chirality Inversion of Assemblies of Bio-based Surfactant Triggered by metal ions

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2018年第2期34卷 155-157页

作者： ZHANG Lujun ZHANG Pei ZHANG Xiudong SONG Jinliang YANG Guanying JIANG Long HAN Buxing Beijing National LaboratoryforMolecular Sciences Key Laboratory of Colloid and Interface and Thermodynamics Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China University of Chinese Academy of Sciences Beijing 100049 P. R. China

The utilization of biomass has attracted much attention during the last decade. Sorbitol is a kind of abundant biomass with multiple chiral centers in its skeleton, indicating an im- portant potential for helical architectures. Helical nanostruc- tures with switchable chirality are attracting much attention due to their crucial roles in many fields.

关键词： Chirality inversion Bio-based surfactant metal ion Assembly Helicity

A New Fluorescent Chemosensor for metal ions Based upon 1,8-Naphthalimide and 8-Hydroxyquinoline

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2011年第10期29卷 2165-2168页

作者：徐晖曾习文代会苓 Laboratory of Pharmaceutical Design ＆ Synthesis College of Science Northwest Agriculture ＆ Forestry University Yangling 712100 China

A new fluorescent chemosensor based upon 1,8-naphthalimide and 8-hydroxyquinoline was synthesized, and its fluorescent properties in the presence of different metal cations （Hg^2＋, Ag^＋, Zn^2＋, Fe^2＋, Cd^2＋, Pb^2＋, Ca^2＋, Cu^2＋, Mg^2＋, and Ba^2＋） were investigated. It displayed fluorescence quenching with some heavy and transition metal （HTM） ions, and the quenching strongly depended on the nature of HTM ions.

关键词： fluorescence sensors 1,8-naphthalimide 8-hydroxyquinoline metal ion