Yuhai Zhang

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We report an epitaxial growth technique for scalable production of hybrid sodium rare-earth fluoride (NaLnF4 ) microcrystals, including NaYF4 , NaYbF4 , and NaLuF4 material systems. The single crystalline nature of the as-synthesized products makes them strong upconversion emission. The freedom of combining a lanthanide activator (Er(3+) or Tm(3+) ) with a(More)
We report the synthesis of luminescent crystals based on hexagonal-phase NaYF4 upconversion microrods. The synthetic procedure involves an epitaxial end-on growth of upconversion nanocrystals comprising different lanthanide activators onto the NaYF4 microrods. This bottom-up method readily affords multicolor-banded crystals in gram quantity by varying the(More)
Probing the nature of nanocrystalline materials such as the surface state, crystal structure, morphology, composition, optical and magnetic characteristics is a crucial step in understanding their chemical and physical performance and in exploring their potential applications. Upconversion nanocrystals have recently attracted remarkable interest due to(More)
The ultimate frontier in nanomaterials engineering is to realize their composition control with atomic scale precision to enable fabrication of nanoparticles with desirable size, shape and surface properties. Such control becomes even more useful when growing hybrid nanocrystals designed to integrate multiple functionalities. Here we report achieving such(More)
from the pristine silica particles. The pathobiological effect observed after 30 s of corona formation does not seem to alter significantly with longer incubation times. The work of Tenzer and colleagues illustrates that a well-characterized protein corona can provide insights into the biocompatibility of a specific nanoparticle. There is, however, still(More)
Precise knowledge and control over the orientation of individual upconverting particles is extremely important for full exploiting their capabilities as multifunctional bioprobes for interdisciplinary applications. In this work, we report on how time-resolved, single particle polarized spectroscopy can be used to determine the orientation dynamics of a(More)
Compared with routine microscopy imaging of a few analytes at a time, rapid scanning through the whole sample area of a microscope slide to locate every single target object offers many advantages in terms of simplicity, speed, throughput, and potential for robust quantitative analysis. Existing techniques that accommodate solid-phase samples incorporating(More)
A Cu-mediated preparation of 2-substitiuted pyrazolo[1,5-a]pyridines from N-benzoylpyridinium imides and terminal alkynes is described using stoichiometric Cu(OAc)2 as both the mediator and the oxidant. Extensive DFT calculations suggest a Cu(III) intermediate via disproportionation of Cu(II).
Organic micropollutants may be present in biosolids, leading to soil contamination when they are recycled in agriculture. A sludge spiked with (14)C-labelled glyphosate (GLY), sodium linear dodecylbenzene sulphonate (LAS), fluoranthene (FLT) or 4-n-nonylphenol (NP) was composted with green waste and the fate of the (14)C-micropollutant residues remaining(More)