Journal of Russian Laser Research - The zero-refractive-index metamaterials have excellent electromagnetic properties, which provide new ideas and methods to realize the control of electromagnetic... 相似文献
Chinese Annals of Mathematics, Series B - In the present article, the authors find and establish stability of multiplier ideal sheaves, which is more general than strong openness. 相似文献
Journal of Radioanalytical and Nuclear Chemistry - A convenient and inexpensive approach for the synthesis of deuterium-labeled thiamphenicol was described. DL-threo-Thiamphenicol-methyl-d3 was... 相似文献
As an emerging host phosphor material, barium chlorapatite (Ba5(PO4)3Cl), is attracting growing attention. However, rare earth-doped Ba5(PO4)3Cl phosphors have mainly been obtained via high temperature-based, energy-consuming techniques. In this contribution, we developed a straightforward, facile room-temperature coprecipitation method in the presence of a specific amount of ethylenediaminetetraacetic acid disodium salt that provided Ba5(PO4)3Cl nanoparticles self-assembled to construct uniform Ba5(PO4)3Cl nanoassemblies (diameter: 80–120 nm) as well as rare earth Tb3+-doped Ba5(PO4)3Cl:xTb3+ nanophosphors. The nanoassemblies were transparent within the ultraviolet and visible spectral range. The Ba5(PO4)3Cl:xTb3+ nanophosphors exhibited four emission peaks under 228-nm excitation, and the optimal doping amount of Tb3+ was 4.0%. In contrast to traditional energy-consuming, high-temperature techniques, the facile room-temperature coprecipitation method developed here represents an attractive alternative route to obtain uniform Ba5(PO4)3Cl nanoassemblies and Ba5(PO4)3Cl:xTb3+ nanophosphors that are candidate luminescent hosts. 相似文献
The chemical constituents of the fungus Verticillium psalliotae were studied. Two new aromadendrane sesquiterpenes inonotin M (1) and inonotin N (2) were isolated from the EtOAc extract of the fungal culture broth. The structures of compounds were elucidated mainly by HRESIMS experiments, and 1D, 2D-NMR spectroscopy analysis. 相似文献
In this study, three different volume expansion ratios of expanded graphite (EG) are prepared and investigated to enhance the heat transfer efficiency of the sodium acetate trihydrate (SAT) composites. A series of SAT composite phase change materials (CPCMs) with EG were prepared. The influence of volume expansion ratio and mass fraction of EG on thermodynamic characteristics of SAT CPCMs was examined, including thermal conductivity, phase change temperature, enthalpy, latent heat storage and release time, and the degree of supercooling. Results showed that SAT CPCMs can be absorbed adequately by EG, and EG could enhance the heat transfer efficiency effectively. But it also brought some problems with the addition of all the three volume expansion ratios of EG, such as the poor enthalpy and serious supercooling. Particularly, the situation gets worse with the increase in mass and expansion ratio of EG. Therefore, it is better to choose the EG with proper expansion ratio or reduce the proportion of the EG which possesses higher expansion ratio. Besides, thermal cycling test and thermogravimetric analysis revealed that the SAT CPCMs with 3 mass% EG showed a good thermal stability.
Fullerene (C60), the third carbon allotrope, has shown great potential in photoelectric materials and drug delivery. However, the low solubility of C60 in polar solvents, especially in water, is the major limiting factor for further applications. The use of ultrasound and amphiphilic block copolymers, poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP), helped to disperse C60 in acidic aqueous solutions. As characterized by dynamic light scattering, transmission electron microscopy, and UV-visible spectroscopy, the C60 colloids had a core-shell structure with C60 aggregated in the micellar cores. The photosensitized generation of singlet oxygen using C60-bound polymer micelle was confirmed by the iodide method. More importantly, C60 and metalloporphyrin complexes could be synthesized by the self-assembly between PEG-b-P4VP/C60 micelle and metalloporphyrin. The stability of metalloporphyrin increased in the presence of the PEG-b-P4VP/C60 micelle. This study provides a method for the solubilization of C60 with many potential applications in biomedicals and photovoltaics. 相似文献