Nanometer-sized metal clusters were prepared inside single crystalline MgO films by vacuum co-deposition of metals and MgO. The atomic structure was studied by high-resolution electron microscopy (HREM) and nm-area el...Nanometer-sized metal clusters were prepared inside single crystalline MgO films by vacuum co-deposition of metals and MgO. The atomic structure was studied by high-resolution electron microscopy (HREM) and nm-area electron diffraction. The size of the clusters is ranging from 1 nm to 3 nm without those larger than 5 nm, and most of them have definite epitaxial orientations with the MgO matrix films. The character of the composite films is very much useful for the studies of various kinds of physical properties with anisotroPy. The physical properties such as electric transport, magnetic, optical absorption, sintering and catalytic ones were thus measured on the same samples analyzed by HREM by using high sensitivity apparatus with interest of clarifying the retationship between the atomic structure and physical properties展开更多
Two kinds of fluorescent nano-probes（pH-A and pH-B） with different diameters for the determination of H＋concentration, based on photo-induced electron transfer mechanism, were synthesized through click reaction. In...Two kinds of fluorescent nano-probes（pH-A and pH-B） with different diameters for the determination of H＋concentration, based on photo-induced electron transfer mechanism, were synthesized through click reaction. In which 1,8-naphthalimide was employed as the fluorophore and N,N-dimethylethylenediamine as the receptor. The effects of particle size and linker length on the photophysical properties of the probe were studied. The results revealed that the nano-probes were more sensitive toward pH with increasing particle size. The fluorescence intensity at 529 nm（I529） of the nano-probe p H-A of 120 nm exhibited good linear relationship with solution＇s pH in the range of 6–8. The probe p H-A displayed excellent selectivity and competition toward proton over other possible coexisted ions, and it could be applied to detect pH in realistic samples（river water, urine）.展开更多
Immiscible polymer blends are an important family of polymer materials.The interfacial thickness between different phases is a very important parameter that dictates,to a great extent,the morphology and properties of ...Immiscible polymer blends are an important family of polymer materials.The interfacial thickness between different phases is a very important parameter that dictates,to a great extent,the morphology and properties of such a blend.This work explores and optimizes an up-to-date atomic force microscopy(AFM)of type NanoIR2^(TM) system in order to quantitatively measure the interfacial thickness of immiscible polymer blends.This system is equipped with two nano-probes capable of detecting the response of a material to an infrared pulse called AFM-infrared spectroscopy mode(AFM-IR)or conducting resonance called AFM-Lorentz Contact Resonance mode(AFM-LCR),respectively.Its potential for quantitatively measuring the interfacial thickness of immiscible polymer blends is evaluated using blends composed of polyamide 6(PA6)and polyolefin elastomer(POE)in the presence or absence of a POE containing maleic anhydride(POE-g-MAH)as a compatibilizer.Surface roughness affects adversely the signal intensity and consequently an accurate measurement of the interfacial thickness.Optimum sample surface preparation procedures are proposed.展开更多
光合细菌是一类具有原始光能合成机制的原核生物,在多种环境中广泛分布,其在废水处理、饲料添加剂等领域的应用备受关注。然而,传统研究光合细菌的方法存在如过程复杂耗时费力、稳定性维持困难、可塑性差等诸多局限性。单细胞技术的发...光合细菌是一类具有原始光能合成机制的原核生物,在多种环境中广泛分布,其在废水处理、饲料添加剂等领域的应用备受关注。然而,传统研究光合细菌的方法存在如过程复杂耗时费力、稳定性维持困难、可塑性差等诸多局限性。单细胞技术的发展为其研究带来了新机遇。本文综述了单细胞水平下挖掘环境光合细菌资源的研究进展,包括纳米二次离子质谱技术(nano-scale secondary ion mass spectrometry,NanoSIMS)、单细胞拉曼光谱法及其与稳定同位素标记结合等技术在光合细菌资源挖掘和机理解析方面的应用。这些技术有助于深入理解光合细菌的光合机制、代谢途径及环境适应机制,为其在污水处理、生物能源生产等领域的应用提供了理论依据和技术支持,对推动环境保护和可持续发展具有重要意义。展开更多
文摘Nanometer-sized metal clusters were prepared inside single crystalline MgO films by vacuum co-deposition of metals and MgO. The atomic structure was studied by high-resolution electron microscopy (HREM) and nm-area electron diffraction. The size of the clusters is ranging from 1 nm to 3 nm without those larger than 5 nm, and most of them have definite epitaxial orientations with the MgO matrix films. The character of the composite films is very much useful for the studies of various kinds of physical properties with anisotroPy. The physical properties such as electric transport, magnetic, optical absorption, sintering and catalytic ones were thus measured on the same samples analyzed by HREM by using high sensitivity apparatus with interest of clarifying the retationship between the atomic structure and physical properties
基金financial support from the National Natural Science Foundation of China (No. 21576085)
文摘Two kinds of fluorescent nano-probes（pH-A and pH-B） with different diameters for the determination of H＋concentration, based on photo-induced electron transfer mechanism, were synthesized through click reaction. In which 1,8-naphthalimide was employed as the fluorophore and N,N-dimethylethylenediamine as the receptor. The effects of particle size and linker length on the photophysical properties of the probe were studied. The results revealed that the nano-probes were more sensitive toward pH with increasing particle size. The fluorescence intensity at 529 nm（I529） of the nano-probe p H-A of 120 nm exhibited good linear relationship with solution＇s pH in the range of 6–8. The probe p H-A displayed excellent selectivity and competition toward proton over other possible coexisted ions, and it could be applied to detect pH in realistic samples（river water, urine）.
基金The financial supports provided, in whole or in part, by the National Natural Science Foundation of China （81071257, 81201192, 81 lO1147, 11272083 ）, Postdoctal Program of China （2011M501297, 2012T50715 ） , and the Fundamental Research Funds for Central Uni- versities （ ZYGX2010X019, ZYGX201OJ101, ZYGX2011 J099） , are greatly appreciated.
基金The authors thank the National Natural Science Foundation of China(No.51973193)the State Key Laboratory of Chemical Engineering(No.SKL-ChE-13D)for their financial support.
文摘Immiscible polymer blends are an important family of polymer materials.The interfacial thickness between different phases is a very important parameter that dictates,to a great extent,the morphology and properties of such a blend.This work explores and optimizes an up-to-date atomic force microscopy(AFM)of type NanoIR2^(TM) system in order to quantitatively measure the interfacial thickness of immiscible polymer blends.This system is equipped with two nano-probes capable of detecting the response of a material to an infrared pulse called AFM-infrared spectroscopy mode(AFM-IR)or conducting resonance called AFM-Lorentz Contact Resonance mode(AFM-LCR),respectively.Its potential for quantitatively measuring the interfacial thickness of immiscible polymer blends is evaluated using blends composed of polyamide 6(PA6)and polyolefin elastomer(POE)in the presence or absence of a POE containing maleic anhydride(POE-g-MAH)as a compatibilizer.Surface roughness affects adversely the signal intensity and consequently an accurate measurement of the interfacial thickness.Optimum sample surface preparation procedures are proposed.
文摘光合细菌是一类具有原始光能合成机制的原核生物,在多种环境中广泛分布,其在废水处理、饲料添加剂等领域的应用备受关注。然而,传统研究光合细菌的方法存在如过程复杂耗时费力、稳定性维持困难、可塑性差等诸多局限性。单细胞技术的发展为其研究带来了新机遇。本文综述了单细胞水平下挖掘环境光合细菌资源的研究进展,包括纳米二次离子质谱技术(nano-scale secondary ion mass spectrometry,NanoSIMS)、单细胞拉曼光谱法及其与稳定同位素标记结合等技术在光合细菌资源挖掘和机理解析方面的应用。这些技术有助于深入理解光合细菌的光合机制、代谢途径及环境适应机制,为其在污水处理、生物能源生产等领域的应用提供了理论依据和技术支持,对推动环境保护和可持续发展具有重要意义。
