检索结果-南通市图书馆

Photoinduced Electron Transfer Between Mono-6-p-nitrobenzoyl-β- cyclodextrin and Adamantanamine-Cn-Co/Ni-porphyrins

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2006年第4期19卷 329-334页

作者： Guo-tao Wen Man-zhou Zhu Hui-yuan Hu xiang-ming meng Zhuo Wang Qing-xiang Guo Department of Chemistry University of Science and Technology of China Hefei 230025 China Provincial Key Laboratory of Research on Wastewater Treatment Technology Anhui Academy of Environmental Science Research Hefei 230051 China

Two series monot ailed porphyrins, Cobalt-5- {4- [ω- （1-adamant aneamino） alkyloxy] phenyl }- 10,15,20-triphenyl porphyrinate （CoPCnA, n=4,5,6） and Nickel-5-{4-[ω-（1-adamantaneamino）alkyloxy]phenyl}-10,15.20- triphenyl porphyrinate （NiPCnA, n=4,5,6）, were synthesized, in which the porphyrin moiety was connected to l-adamantanamine via a flexible hydrocarbon chain. The fluorescence quenching between these donor substrates and mono-6-p-nitrobenzoyl-β-cyclodextrin （NBCD） was studied in detail. Distinct fluorescence quenching occured in these supramolecular systems. This quenching was attributed to the photoinduced electron transfer （PET） inside the supramolecular assembly between the porphyrin donors and cyclodextrin acceptors. Detailed Stern-Volmer constants were measured and they were partitioned into dynamic Stern- Volmer quenching constants and static binding constants. It was demonstrated that the PET interaction between the porphyrin subunits and NBCD is indeed effective.

关键词： Photoinduced electron transfer Host-guest complex Cyclodextrin Supramolecular system Fluorescence quenching

A novel selective fluorescent chemosensor for Cu(Ⅱ)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2007年第11期18卷 1403-1406页

作者： Mao xiang Wang xiang ming meng Man Zhou Zhu Qing xiang Guo Department of Chemistry University of Science and Technology of China Hefei 230026 China

A novel fluorescence enhancement Cu^2＋ chemosensor derived from coumarin was prepared. Emission study found that it exhibits evident Cu^2＋-arnplified fluorescence prior to Co^2＋, Pb^2＋, Mg^2＋, Mn^2＋, Ni^2＋, Zn^2＋, Fe^3＋, Ag^＋ and Cd^2＋, and the largest emission enhancement factor is about 9 at a ratio of 2：1 （chemosensor 1/Cu^2＋）.

关键词： Cu^2+ chemosensor Fluorescence 荧光性 Coumarin

Novel fluorescent chemosensor for Ag^+ based on coumarin fluorophore

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2008年第8期19卷 977-980页

作者： Mao xiang Wang xiang ming meng Man Zhou Zhu Qing xiang Guo Department of Chemistry University of Science and Technology of China Hefei 230026 China

A novel chemosensor 1 （CS1） bearing one coumarin and two carbodithioate groups was synthesized and its fluorescent sensing behavior toward metal ions was investigated. Ag^＋ addition to a CH3COCH3/H2O （3：7, v：v） solution of CS1 gave a significantly quenched fluorescence. Other ions including Pb^2＋, Zn^2＋, Cu^2＋, Ca^2＋, Cd^2＋, Co^2＋, Mg^2＋, Mn^2＋, Hg^2＋, Ag^＋, Ni^2＋ induced no or much smaller spectral changes. This constitutes an ON-OFF Ag^＋-selective fluorescent chemosensor.

关键词： Ag^+ chemosensor Fluorescence PET Coumarin

Synergistic effect of Zr and Mo on precipitation and high-temperature properties of Al-Si-Cu-Mg alloys

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第1期21卷 71-81页

作者： Chao Gao Bing-rong Zhang Yin-ming Li Zhi-ming Wang xiang-bin meng Faculty of Mechanical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Hebei Ounai Machinery Mould Co.Ltd. Xingtai 054500HebeiChina

This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,to be used in automobile engines at high temperatures,was prepared by adding Zr and Mo into Al-Si-Cu-Mg *** synergistic effects of Zr and Mo on the microstructure evolution and high-temperature mechanical properties were *** show that the addition of Zr and Mo generates a series of intermetallic phases dispersed in the *** can improve the strength of the alloy by hindering dislocation movement and crack *** addition,some nano-strengthened phases show coherent interfaces with the matrix and improve grain *** addition of Mo greatly improves the heat resistance of the *** extremely low diffusivity of Mo enables it to improve the thermal stability of the intermetallic phases,inhibit precipitation during aging,reduce the size of the precipitates,and improve the heat resistance of the alloy.

关键词： Al-Si-Cu-Mg alloy high-temperature properties Zr-Mo-rich intermetallics nano-strengthening phases

Discovery, structure,and chemical synthesis of disulfide-rich peptide toxins and their analogs

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2018年第7期29卷 1033-1042页

作者： Ge-Min Fang Xiao-Xu Chen Qian-Qian Yang Liang-Jing Zhu Ning-Ning Li Hai-Zhu Yu xiang-ming meng Institute of Physical Science and Information Technology Anhui University Department of Chemistry Anhui University

Recently, medicinal peptide molecules are of great interest to many international pharmaceutical companies, mainly because of their relatively lower research costs, shorter research cycles, and the greater likelihood of being drugs, when compared with traditional small molecules. Due to the great variety in molecule structures and the diverse biological functions, disulfide-rich peptide toxins have become a shining molecular library for the development of polypeptide drugs. In view of the increasing amount of related publications, here we summarize the discovery, structural elucidation and chemical synthesis of disulfide-rich peptide toxins and their analogs.

关键词： Peptide toxins Conotoxins Cyclotides Disulfide mimics Chemical synthesis

A coumarin-based colorimetric and fluorescent probe for the highly selective detection of Au^(3+) ions

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2016年第9期27卷 1563-1566页

作者： Qi Wang Yan Feng Jun Jiang Wen-Juan Wang Jiu-You Chen Hong-Ting Sheng xiang-ming meng Man-Zhou Zhu School of Chemistry and Chemical Engineering & Center for Atomic Engineering of Advanced Materials Anhui University

We develop a novel coumarin-all〈yne derivative （NC7-AL）, which can specifically react with Au^3＋ and give a colorimetric and fluorescent ＂turn-on＂ response toward Au3~, Notably, other alkynophilic metal species such as Au^＋, Ag^＋, Pd^2＋, Ni^2＋, Cu^2＋, and Hg^2＋ do not produce an interfering signal. A good linear relationship between emission intensity at 420 nm and Au^3＋ concentration from 0 to 2 equivalent is observed, and the detection limit （3σ/k） is estimated to be ca. 3.58 nmol/L. Harnessing the Au^3＋ .

关键词： Coumarin Alkyne Au^3+ Colorimetric Fluorescent probe

Decomposition mechanisms of nuclear-grade cationic exchange resin by advanced oxidation processes:Statistical molecular fragmentation model and DFT calculations

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第1期135卷 433-448页

作者： xiang meng Pierre Désesquelles Lejin Xu Department of Nuclear Engineering and Technology School of Energy and Power EngineeringHuazhong University of Science&TechnologyWuhan 430074China CNRS Laboratoire de Physique des Gaz et des PlasmasUniversitéParis-SaclayOrsay 91405France State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The treatment and disposal of radioactive waste are presently facing great *** ion exchange resins have become a focus of attention due to their high production and serious environmental *** this paper,a simplified model of cationic exchange resin is proposed,and the degradation processes of cationic resin monomer initiated by hydroxyl radicals(·OH)are clarified by combining statistical molecular fragmentation(SMF)model and density functional theory(DFT)*** prediction of active sites indicates that the S-O bonds and the C-S bond of the sulfonic group are more likely to react during the *** meta-position of the sulfonic group on the benzene ring is the most active site,and the benzene ring without the sulfonic group has a certain *** C11-C14 and C17-C20 bonds,on the carbon skeleton,are the most easily *** is also found that dihydroxy addition and elimination reactions play a major role in the process of desulfonation,carbon skeleton cleavage and benzene ring *** decomposition mechanisms found through the combination of physical models and chemical calculations,provide theoretical guidance for the treatment of complex polycyclic aromatic hydrocarbons.

关键词： Cationic exchange resin Statistical molecular fragmentation model Density functional theory Hydroxyl radical Decomposition mechanism

Microstructure and mechanical properties of a cast TRIP-assisted multiphase stainless steel

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 221-228页

作者： meng-xin Wang Zi-xiang Wu Jing-yu He xiang Chen School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

Stainless steels are used in a wide range of complex environments due to their excellent corrosion *** stainless steels can offer an excellent combination of strength,toughness and corrosion resistance due to the coexistence of different *** microstructure and mechanical properties of a novel cast multiphase stainless steel,composed of martensite,ferrite,and austenite,were investigated following appropriate heat treatment processes:solution treatment at 1,050℃ for 0.5 h followed by water quenching to room temperature,and aging treatment at 500℃ for 4 h followed by water quenching to room *** show reversed austenite is formed by diffusion of Ni element during aging process,and the enrichment of Ni atoms directly determines the mechanical stability of *** austenite with a lower Ni content undergoes a martensitic transformation during plastic *** tensile strength of the specimen exceeds 1,100 MPa and the elongation exceeds 24%after solid solution,and further increases to 1,247 MPa and 25%after aging *** enhancement is due to the TRIP effect of austenite and the precipitation of the nanoscale G-phase pinning dislocations in ferrite and martensite.

关键词： multiphase stainless steel mechanical properties TRIP effect reversed austenite G-phase

Attractor for the Extensible Beam Equation with Nonlocal Weak Damping on Time–Dependent Space

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第4期40卷 1115-1126页

作者： Chun xiang ZHAO Feng Juan meng Institute of Applied System Analysis Jiangsu UniversityZhenjiang 212013P.R.China School of Mathematics and Physics Jiangsu University of TechnologyChangzhou 213001P.R.China

In this article,we consider the long-time behavior of extensible beams with nonlocal weak damping:ε(t)u_(tt)+Δ^(2)u-m(‖▽u‖^(2))Δu+‖u_(t)‖^(p_(u_(t)))+f(u)=h,whereε(t)is a decreasing function vanishing at *** the theory of process on time-dependent spaces,we investigate the existence of the time-dependent attractor by using the Condition(C_(t))method and more detailed *** results obtained essentially improve and complete some previous works.

关键词： Time-dependent attractor extensible beams equation nonlocal weak damping