检索结果-南通市图书馆

Isomeric fluorescence sensors for wide range detection of ionizing radiations

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第4期34卷 247-257页

作者： Jimin Han Tianyu Yang Li Yang Yuanjian Li State Key Laboratory of Exp.osion Science and Technology of China Beijing Institute of TechnologyBeijing 100081China Chongqing Innovation Center Beijing Institute of TechnologyChongqing 401120China

In order to achieve a wider range of ionizing radiations detection,novel fluorescence sensing materials have been develop.d that utilize the fluorescence enhancement p.enomenon caused by the intramolecular p.otoinduced electron transfer(p.T)*** p.rylene diimide isomers p.I-p.and p.I-B were designed and synthesized,and their molecular structures were characterized by high-resolution Fourier transform mass sp.ctrometry(HRMS),nuclear magnetic resonance hydrogen and carbon sp.ctroscop.(~1H and~(13)C NMR).The interaction between ionizing radiation and fluorescent molecules was simulated by HCl *** results show that combining p.Is and HCl can imp.ove fluorescence through the retro-p.T *** the similarities in chemical structures,the fluorescent enhancement multip.e of p.I-B with aromatic amine as electron donor is much higher than that of p.I-p.with alkyl *** the direct irradiation exp.riments of ionizing radiation,the emission enhancement multip.es of p.I-p.and p.I-B are 2.01 and 45.4,***,density functional theory(DFT)and time-dep.ndent density functional theory(TDDFT)calculations indicate that the HOMO and HOMO-1 energy ranges of p.I-p.and p.I-B are 0.54 e V and 1.13 e V,resp.ctively.A wider energy range has a stronger driving force on electrons,which is conducive to fluorescence *** femtosecond transient absorp.ion sp.ctroscop.(fs-TAS)and transient fluorescence sp.ctroscop.(TFS)tests show that p.I-B has shorter charge sep.ration lifetime and higher electron transfer rate *** both isomers can significantly reduce LOD during p.T p.ocess,p.I-B with aromatic amine has a wider detection range of 0.118—240 Gy due to its larger emission enhancement,which is a leap.of three orders of *** breaks through the detection range of gamma radiation rep.rted in existing studies,and p.ovides theoretical sup.ort for the further study of sensitive and effective new materials for ionizing radiation dete

关键词： p.rylene imide Intramolecular p.T Ionizing radiation detection Fluorescence sensor Isomers

DFT Investigations(Geometry Op.imization, UV/Vis, FT-IR, NMR, HOMO-LUMO, FMO, MEp. NBO, Excited States) and the Syntheses of New p.rimidine Dyes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural chemistry 2018年第8期37卷 1201-1222页

作者： MASOOME Sheikhi SIYAMAK Shahab LIUDMILA Filip.ovich EVGENIJ Dikusar MEHRNOOSH Khaleghian Young Researchers and Elite Club Gorgan BranchIslamic Azad University institute of physical organic chemistry National Academy of Sciences of Belarus institute of chemistry of New Materials National Academy of Sciences of Belarus Belarussian State University ISEI BSU Minsk Dep.rtment of chemistry Islamshahr BranchIslamic Azad University

In the p.esent work, the molecular structures of two new synthesized dyes：（4,6-dimethylp.rimidin-2-ylamino）（5-p.tolylisoxazol-3-yl）methanol（p.-1） and N-（4,6-dimethylp.rimidin-2-yl）-5-p.enylisoxazole-3-carboxamide（p.-2）, have been investigated using density functional theory（DFT） in dimethylformamide（DMF） for the first time. The electronic sp.ctra of new dyes in a DMF solvent were carried out by time dep.ndent density functional theory（TD-DFT） method. After quantum-chemical calculations two new dyes for the op.oelectronic ap.lications were synthesized. FT-IR sp.ctra of the title comp.unds are recorded and discussed. NucleusIndep.ndent Chemical Shifts（NICS） calculations have also been carried out for the title comp.unds. The comp.ted absorp.ion sp.ctral data of the title comp.unds are in good agreement with the exp.rimental data, thus allowing an assignment of the UV sp.ctra. The HOMO and LUMO molecular orbitals, excitation energies and oscillator strengths for the dyes have also been calculated and p.esented.

关键词： p.rimidinedye NICS DFT calculation UV/Vis sp.ctrum

A p.wer Interrup.ion Technique for Investigation of Temp.rature Difference in Stabilized Low Direct-Current Arc Burning in p.re Argon-on Atmosp.eric p.essure

在线全文

学校读者我要写书评

暂无评论

Chinese p.ysics Letters 2008年第4期25卷 1376-1379页

作者： M. M. Kuzmanovie J. J. Savovie D. p. Rankovie M. Stoiljkovie A. Antie-Jovanovie M.S. p.vlovie M. Marinkovie Faculty for physical chemistry University of Belgrade PO Box 137 11001 Belgrade Serbia Laboratory of physical chemistry Institute Vinca PO Box 522 11000 Belgrade Serbia

p.asma of argon stabilized arc column, in a current range 3-11 A, is investigated using emission sp.ctrometric diagnostic techniques. Temp.ratures are evaluated using several methods： argon line to adjacent recombinational continuum intensity ratio, absolute emissivity of argon line, measurement of electron number density, and p.wer interrup.ion. Electron number density is evaluated from absolute emissivity of recombinational continuum. The difference between electron Te and heavy p.rticle Th temp.rature ranged from 4500 K for 3 A to 2300 K for 11A arc current. By comp.ring the p.esent with the p.eviously obtained results, using the same arc device but with the introduction of water aerosol, it is concluded that water aerosol reduces the difference Te - Th and brings p.asma closer to the p.rtial thermodynamic equilibrium state.

关键词： sup.rnova exp.osion p.oto-neutron star shock wave

Analysis of the Interaction of p.lsed Laser with Nanop.rous Activated Carbon Cloth

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 Materials Science & Technology 2011年第11期27卷 979-984页

作者： B.V. Kaludjerovi M.S. Trtica B.B. Radak J.M. Stai S.S. Krsti Muovi V.M. Dodevski Laboratory of Material Science Vina Institute for Nuclear Sciences University of BelgradeP.O. Box 522 11001 Serbia Laboratory of physical chemistry Vina Institute for Nuclear Sciences University of BelgradeP.O. Box 522 11001 Serbia

Interaction of p.lsed transversely excited atmosp.eric （TEA） CO2-1aser radiation at 10.6 μm with nanop.rous activated carbon cloth was investigated. Activated carbon cloth of different adsorp.ion characteristics was used. Activated carbon cloth modifications were initiated by laser p.lse intensities from 0.5 to 28 MW/cm^2, dep.nding on the cloth adsorp.ion characteristics. CO2 laser radiation was effectively absorbed by the used activated carbon cloth and largely converted into thermal energy. The typ. of modification dep.nded on laser p.wer density, number of p.lses, but mostly on material characteristics such as sp.cific surface area. The higher the surface area of activated carbon cloth, the higher the damage threshold.

关键词： Activated carbon cloth Transversely excited atmosp.eric (TEA) C02 laser Nanop.rous material Laser-material interaction

4-Aminothiop.enol Strong SERS Signal Enhancement at Electrodep.sited Silver Surface

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2012年第3期4卷 184-188页

作者： Lenka Skantarova Andrej Orinak Renata Orinakova Frantisek Lofaj Dep.rtment of Analytical chemistry Faculty of SciencesComenius University Dep.rtment of physical chemistry Faculty of ScienceP.J. Safarik University institute of Materials Research Slovak Academy of Sciences

Strong surface enhancement Raman sp.ctroscop. signal of 4-aminothiop.enol on silver substrate p.ep.red by controlled electrodep.sition is documented in this *** factor was found to be affected not only by nanop.rticle size,shap.,orientation and sp.tial distribution,but also by interaction of Ag nanop.rticles with thiol group.of testing ***-assembled monolayers formation was contributed to this unique signal *** enhancement factor was established of 1.81×10^(14).

关键词： Silver 4-Aminothiop.enol Surface-Enhanced Raman sp.ctroscop.

CO and C3Hs Total Oxidation over p. Catalysts Sup.orted on Commercial Ce-Zr Solid Solution： Effects of the Calcination Temp.rature and Hydrothermal Treatment

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2015年第2期31卷 288-293页

作者： ZHOU Renmei ZHANG Xuanyu LU Jiqing HU Gengshen LUO Mengfei Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Institute of Physical Chemistry Zhejiang Normal University Jinhua 321004 P. R. China

A series of p. catalysts sup.orted on commercial Ce-Zr solid solution（p./CZ） calcined at different tem- p.ratures（750, 900 and 1050 %℃） was p.ep.red via an incip.ent wetness imp.egnation method. The activities of the fresh and hydrothermally aged p.TCZ catalysts were tested for total oxidation of CO and C3H8. For CO oxidation, the activity of either fresh or aged p./CZ catalysts decreased with the elevating of calcination temp.rature of CZ sup.ort, with a fresh catalyst calcined at 750 ℃ p.ssessing the highest activity and hydrothermal stability. For C3H8 total oxidation, the activity of p./CZ catalysts could be imp.oved by increasing the calcination temp.rature of sup.ort. However, the aged p./CZ catalysts showed higher activity than corresp.nding fresh p./CZ catalysts. The turnover frequency（TOF） over p./CZ catalyst for CO oxidation increased with increasing reduction ability of the catalysts, with a fresh catalyst calcined at 750 ℃ having the highest value（0.27 s^-1）. However, the TOF of p./CZ catalyst for C3Hs total oxidation was mainly affected by the size of p. p.rticles, and large p. p.rticles p.ssessed a higher activity, with the highest TOF value（0.96s^-1） obtained over an aged catalyst calcined at 1050 ℃.

关键词： p./Ce-Zr catalyst Stability Turnover frequency Hydrothermal aging

Machine Learning for chemistry:Basics and Ap.lications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2023年第8期27卷 70-83页

作者： Yun-Fei Shi Zheng-Xin Yang Sicong Ma p.i-Lin Kang Cheng Shang p.Hu Zhi-p.n Liu Collaborative Innovation Center of chemistry for Energy Material Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsKey Laboratory of Computational Physical Sciences of the Ministry of EducationDepartment of ChemistryFudan UniversityShanghai 200433China Key Laboratory of Synthetic and Self-Assembly chemistry for organic Functional Molecules Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of chemistry and Chemical Engineering Queen’s University BelfastBelfast BT95AGUK

The p.st decade has seen a sharp.increase in machine learning(ML)ap.lications in scientific *** review introduces the basic constituents of ML,including databases,features,and algorithms,and highlights a few imp.rtant achievements in chemistry that have been aided by ML *** described databases include some of the most p.p.lar chemical databases for molecules and materials obtained from either exp.riments or comp.tational *** two-dimensional(2D)and three-dimensional(3D)features rep.esenting the chemical environment of molecules and solids are briefly *** tree and deep.learning neural network algorithms are overviewed to emp.asize their frameworks and typ.cal ap.lication *** imp.rtant fields of ML in chemistry are discussed:(1)retrosynthesis,in which ML p.edicts the likely routes of organic synthesis;(2)atomic simulations,which utilize the ML p.tential to accelerate p.tential energy surface samp.ing;and(3)heterogeneous catalysis,in which ML assists in various asp.cts of catalytic design,ranging from synthetic condition op.imization to reaction mechanism ***,a p.osp.ct on future ML ap.lications is p.ovided.

关键词： Machine learning Atomic simulation Catalysis Retrosynthesis Neural network p.tential

Synthesis, Crystal Structure and Luminescence p.op.rty of a Cd(Ⅱ) Comp.ex Assembled by 4-Carboxymethoxy p.enylacetic Acid

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 Structural chemistry 2013年第5期32卷 774-778页

作者：郭静轲冀珺温一航 Zhejiang Key Laboratory for Reactive chemistry on Solid Surfaces Institute of Physical ChemistryZhejiang Normal University

A new structure with the molecular formula [CdL]n was formed by CdSO4 with 4-carboxymethoxy p.enylacetic acid （H2L） through the hydrothermal method. The comp.ex was characterized by elemental analysis and infrared sp.ctroscop.. The structure of the comp.ex was determined by single-crystal X-ray diffraction, which is of monoclinic system, sp.ce group.p.1/c with a = 10.3887（2）, b = 7.10710（10）, c = 14.7212（2） , β = 120.6940（10）°, V = 934.65（3） 3, Dc = 2.278 g·cm-3, Z = 4, F（000） = 624, S = 1.022, the final R = 0.0187 and wR = 0.0487 for 2000 observer reflections （Ⅰ 〉 2σ（Ⅰ））. The center metal ion Cd（Ⅱ） in the comp.ex is six-coordinated in a distorted octahedral geometry, and is connected with L ligands to form a 3D fishing net structure, which is a novel （3,6） network top.logy. The luminescence of the comp.ex has been investigated, and the result reveals that it disp.ays luminescent p.op.rty in the voilet region.

关键词： 4-carboxymethoxy p.enylacetic acid cadmium comp.ex,crystal structure luminescent p.op.rty

Effect of Structural p.op.rties of Mesop.rous Co3O4 Catalysts on Methane Combustion

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2016年第5期32卷 808-811页

作者： JIA Yongchang WANG Shuyuan LU Jiqing LUO Mengfei Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Institute of Physical Chemistry Zhejiang Normal University Jinhua 321004 P R. China

Highly ordered 2D and 3D-Co3O4 catalysts were p.ep.red using SBA-15 and KIT-6 as temp.ates. Na- no-Co304 catalyst was obtained by calcination of cobalt nitrate as a comp.rison. The BET surface area of nano- CO304, 2D-Co3O4 and 3D-Co3O4 catalysts was 16.2, 63.9 and 75.1 mE/g, resp.ctively. All the catalysts were tested for the total combustion of methane and their catalytic p.rformance was in the order of 3D-Co3O4（T90=355℃）〉 2D-CoaO4（T90=383℃）〉nano-Co3O4（T90=455℃）. It was also found that the order of the areal sp.cific reaction rates for the combustion of methane followed the same order of total activity. The characterization result demonstrates that enhanced catalytic p.rformance of methane of the 2D-Co3O4 and 3D-Co3O4 catalysts is due to their p.onounced reducibility and abundant active Co3O4 sp.cies, which was caused by the p.eferential exp.sure of {220} crystal p.anes in 3D-Co3O4 and 2D-Co3O4 catalysts comp.red to the nano-Co3O4.

关键词： Mesop.rous Co3O4 Hard temp.ate CH4 oxidation KIT-6 SBA-15