A naturally occurring nitrogen heterocycle-based Schiff base sensor 8-methyl-2-oxo-1,2-dihydroquinoline-3-carboxaldehyde-4N-phenylsemicarbazone(8MPS)was synthesized;a highly sensitive and selective“on-off-on”chemose...A naturally occurring nitrogen heterocycle-based Schiff base sensor 8-methyl-2-oxo-1,2-dihydroquinoline-3-carboxaldehyde-4N-phenylsemicarbazone(8MPS)was synthesized;a highly sensitive and selective“on-off-on”chemosensor for aspartic acid in aqueous solution was established.展开更多
An open-framework germanate denoted as SU-79 with the chemical formula[Ge_(12.5)O_(26)(OH)_(2)]-[Ni(C_(3)N_(2)H_(10))_(2)]_(1.1)(NH_(4))_(0.8)(C_(3)N_(2)H_(12))_(0.5)(C_(3)N_(2)H_(10))_(1.5)(H_(2)O)_(2)has been synthe...An open-framework germanate denoted as SU-79 with the chemical formula[Ge_(12.5)O_(26)(OH)_(2)]-[Ni(C_(3)N_(2)H_(10))_(2)]_(1.1)(NH_(4))_(0.8)(C_(3)N_(2)H_(12))_(0.5)(C_(3)N_(2)H_(10))_(1.5)(H_(2)O)_(2)has been synthesized under hydro/solvothermal conditions using[Ni(1,2-pda)2]^(2+)(1,2-pda=1,2-diaminopropane)and 1,2-pda as templates.Owing to the complicated pseudo-merohedral twinning in the crystals,the rotation electron diffraction(RED)method was used for the unit cell and space group determination.展开更多
This study reports the preparation and characterization of silver nanoparticles synthesized by the mediation of the plant weed Stachytarpheta cayennensis through solution method. Ultraviolet visible spectroscopy (UV-V...This study reports the preparation and characterization of silver nanoparticles synthesized by the mediation of the plant weed Stachytarpheta cayennensis through solution method. Ultraviolet visible spectroscopy (UV-Vis) determines the presence of nanoparticles in the solution. Infrared spectroscopy (IR) proves organic molecules at the particles interface. Powder X-ray diffraction (PXRD) provides phase composition and crystallinity. Shape was showed by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) demonstrated the elemental mapping of the silver nanoparticles. Hydrogen peroxide scavenging and phosphomolybdenum antioxidant assays, egg albumin denaturation anti-inflammation study, and the formation mechanism complete the study. The particles have been found composed of pure silver Ag and silver chloride AgCl nanocrystallites. The average crystallite sizes were found to be 13 nm and 20 nm for Ag and AgCl respectively. A Rietveld refinement based XRD pattern data followed by Williamson-Hall plot allows a size and strain analysis. Based on SEM, spherical agglomerates materials were formed and EDX proved the presence of Cl- ions. The reaction formation mechanism of Ag and AgCl is proposed to be simultaneous and competitive. The silver nanoparticles moderately inhibit the denaturation of egg albumin and exhibit antioxidant action;hence, the nanoparticles could be considered as a potential source for biomedical applications.展开更多
Transmission electron microscopy(TEM)is an important tool for structure characterization of zeolite materials.Structural information can be obtained by different TEM techniques,for example electron diffraction(ED),hig...Transmission electron microscopy(TEM)is an important tool for structure characterization of zeolite materials.Structural information can be obtained by different TEM techniques,for example electron diffraction(ED),high-resolution transmission electron microscopy(HRTEM),scanning transmission electron microscopy(STEM)and electron tomography(ET),each with its own advantages and limitations.These techniques are briefly introduced.Examples are given to show how these techniques can be used to solve various structure-related problems in zeolites.With this review we will describe the basic principles of transmission electron microscopy techniques for structural characterization,including recent methodological advancements.Advantages as well as challenges of using TEM for structural characterization will be described in relation to other methods.Examples of structural characterization of zeolites will be given for each of the methods.展开更多
基金the Department of Science and Technology and Ministry of Science and Technology,Government of India,New Delhi,India,for the INSPIRE Fellowship.Grant number for the INSPIRE Fellowship is IF150603,dated 10.04.2015.
文摘A naturally occurring nitrogen heterocycle-based Schiff base sensor 8-methyl-2-oxo-1,2-dihydroquinoline-3-carboxaldehyde-4N-phenylsemicarbazone(8MPS)was synthesized;a highly sensitive and selective“on-off-on”chemosensor for aspartic acid in aqueous solution was established.
基金supported by the National Basic Research Program of China(no.2013CB933402),the Swedish Research Council(VR)and the Swedish Governmental Agency for Innovation Systems(VINNOVA)through the Berzelii Center EXSELENT and the Göran-Gustafsson Foundation for Nature Sciences and Medical Research.
文摘An open-framework germanate denoted as SU-79 with the chemical formula[Ge_(12.5)O_(26)(OH)_(2)]-[Ni(C_(3)N_(2)H_(10))_(2)]_(1.1)(NH_(4))_(0.8)(C_(3)N_(2)H_(12))_(0.5)(C_(3)N_(2)H_(10))_(1.5)(H_(2)O)_(2)has been synthesized under hydro/solvothermal conditions using[Ni(1,2-pda)2]^(2+)(1,2-pda=1,2-diaminopropane)and 1,2-pda as templates.Owing to the complicated pseudo-merohedral twinning in the crystals,the rotation electron diffraction(RED)method was used for the unit cell and space group determination.
基金the German Academic Exchange Service DAAD for a generous Professor Fellowship(grant No.768048).
文摘This study reports the preparation and characterization of silver nanoparticles synthesized by the mediation of the plant weed Stachytarpheta cayennensis through solution method. Ultraviolet visible spectroscopy (UV-Vis) determines the presence of nanoparticles in the solution. Infrared spectroscopy (IR) proves organic molecules at the particles interface. Powder X-ray diffraction (PXRD) provides phase composition and crystallinity. Shape was showed by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) demonstrated the elemental mapping of the silver nanoparticles. Hydrogen peroxide scavenging and phosphomolybdenum antioxidant assays, egg albumin denaturation anti-inflammation study, and the formation mechanism complete the study. The particles have been found composed of pure silver Ag and silver chloride AgCl nanocrystallites. The average crystallite sizes were found to be 13 nm and 20 nm for Ag and AgCl respectively. A Rietveld refinement based XRD pattern data followed by Williamson-Hall plot allows a size and strain analysis. Based on SEM, spherical agglomerates materials were formed and EDX proved the presence of Cl- ions. The reaction formation mechanism of Ag and AgCl is proposed to be simultaneous and competitive. The silver nanoparticles moderately inhibit the denaturation of egg albumin and exhibit antioxidant action;hence, the nanoparticles could be considered as a potential source for biomedical applications.
基金supported by the Swedish Research Council(VR,No.2017-0432)the Swedish Governmental Agency for Innovation Systems(VINNOVA)+1 种基金the Knut&Alice Wallenberg Foundation through the project grant 3DEM-NATURThe EM facility was supported by the Knut and Alice Wallenberg Foundation.TW acknowledges the Swedish Research Council(VR)for an International Postdoc grant(2014-06948).
文摘Transmission electron microscopy(TEM)is an important tool for structure characterization of zeolite materials.Structural information can be obtained by different TEM techniques,for example electron diffraction(ED),high-resolution transmission electron microscopy(HRTEM),scanning transmission electron microscopy(STEM)and electron tomography(ET),each with its own advantages and limitations.These techniques are briefly introduced.Examples are given to show how these techniques can be used to solve various structure-related problems in zeolites.With this review we will describe the basic principles of transmission electron microscopy techniques for structural characterization,including recent methodological advancements.Advantages as well as challenges of using TEM for structural characterization will be described in relation to other methods.Examples of structural characterization of zeolites will be given for each of the methods.
