Simulation approach includes such processes as photon emissions from X-ray tube with a spectral distribution, total reflection on the sample support, photoelectric effect in thin layer sample, as well as characteristi...Simulation approach includes such processes as photon emissions from X-ray tube with a spectral distribution, total reflection on the sample support, photoelectric effect in thin layer sample, as well as characteristic line absorption and detection. The calculation results are in agreement with experimental ones.展开更多
INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secret...INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secreted; they give no information about the secretion process or mechanism of exocytosis. In recent years, an imaging technique known as total internal reflection fluorescence (TIRF) microscopy has been employed to study insulin secretion.展开更多
A spectrometric setup to perform total internal reflection fluorescence (TIRF) and synchronous TIRF measurements at solid/liquid interfaces is presented. The combination of TIRF and synchronous fluorescence was propo...A spectrometric setup to perform total internal reflection fluorescence (TIRF) and synchronous TIRF measurements at solid/liquid interfaces is presented. The combination of TIRF and synchronous fluorescence was proposed to analyze simultaneously different components at interfaces. The TIRF excitation, emission and synchronous spectra of a watersoluble porphyrin were obtained from water/glass interface using this setup without the existence of a surfactant.展开更多
Total internal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) at the glass-water...Total internal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS4-) and diprotonated (H2TPPS2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface.展开更多
Fluorescence microscopy has evolved from a purely biological tool to a powerful chemical instrument for imaging and kinetics research into nanocatalysis.And the demand for high signal-to-noise ratio and temporal–spat...Fluorescence microscopy has evolved from a purely biological tool to a powerful chemical instrument for imaging and kinetics research into nanocatalysis.And the demand for high signal-to-noise ratio and temporal–spatial resolution detection has encouraged rapid growth in total internal reflection fluorescence microscopy(TIRFM).By producing an evanescent wave on the glass–water interface,excitation can be limited to a thin plane to ensure the measured accuracy of kinetics and image contrast of TIRFM.Thus,this unique physical principle of TIRFM makes it suitable for chemical research.This review outlines applications of TIRFM in the field of chemistry,including imaging and kinetics research.Hence,this review could provide guidance for beginners employing TIRFM to solve current challenges creatively in chemistry.展开更多
A new method is proposed to prospect copper deposits with portable XRF analyzer. The method is based on the close relation between Cu and the chalcophile elements or some other elements in the geochemical anomalies of...A new method is proposed to prospect copper deposits with portable XRF analyzer. The method is based on the close relation between Cu and the chalcophile elements or some other elements in the geochemical anomalies of a Cu deposit. Applications of the technique in Northeast China are presented.展开更多
文摘Simulation approach includes such processes as photon emissions from X-ray tube with a spectral distribution, total reflection on the sample support, photoelectric effect in thin layer sample, as well as characteristic line absorption and detection. The calculation results are in agreement with experimental ones.
文摘INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secreted; they give no information about the secretion process or mechanism of exocytosis. In recent years, an imaging technique known as total internal reflection fluorescence (TIRF) microscopy has been employed to study insulin secretion.
文摘A spectrometric setup to perform total internal reflection fluorescence (TIRF) and synchronous TIRF measurements at solid/liquid interfaces is presented. The combination of TIRF and synchronous fluorescence was proposed to analyze simultaneously different components at interfaces. The TIRF excitation, emission and synchronous spectra of a watersoluble porphyrin were obtained from water/glass interface using this setup without the existence of a surfactant.
文摘Total internal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS4-) and diprotonated (H2TPPS2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface.
基金This work was supported by the National Science Foundation of China(21925205,22072145,22102172,21721003)。
文摘Fluorescence microscopy has evolved from a purely biological tool to a powerful chemical instrument for imaging and kinetics research into nanocatalysis.And the demand for high signal-to-noise ratio and temporal–spatial resolution detection has encouraged rapid growth in total internal reflection fluorescence microscopy(TIRFM).By producing an evanescent wave on the glass–water interface,excitation can be limited to a thin plane to ensure the measured accuracy of kinetics and image contrast of TIRFM.Thus,this unique physical principle of TIRFM makes it suitable for chemical research.This review outlines applications of TIRFM in the field of chemistry,including imaging and kinetics research.Hence,this review could provide guidance for beginners employing TIRFM to solve current challenges creatively in chemistry.
文摘A new method is proposed to prospect copper deposits with portable XRF analyzer. The method is based on the close relation between Cu and the chalcophile elements or some other elements in the geochemical anomalies of a Cu deposit. Applications of the technique in Northeast China are presented.