Surface modification of hydrophobic NaYF_4:Yb,Er upconversion nanophosphors and their applications for immunoassay

β-NaYF4:Yb,Er upconversion nanophosphor (UCNP) is known as one of the most efficient NIR-to-visible upconversion materials, which shows great potential in bioanalytical chemistry and bioimaging. However, its applications are greatly limited due to its low water dispersibility and thus poor biocompatibility. In this paper, poly(acrylic acid) (PAA)-based ligand exchange strategies are carried out to modify oleic acid-capped hydrophobic β-NaYF4:Yb,Er UCNPs into hydrophilic ones. After efficient surface modific...     

An overview of design for CSNS/RCS and beam transport

The China Spallation Neutron Source (CSNS) is the first accelerator-based pulsed neutron source in China. Its accelerators are made up of an 80 MeV H⁻ linac, a Rapid Cycling Synchrotron (RCS) and two beam transport lines. RCS accumulates and accelerates protons to the design energy of 1.6 GeV, and extracts high energy beam to strike the target. The overview of RCS is presented, and the key problems of the physics design are discussed. The two beam transport lines, from linac to RCS and from RCS to the target, are also introduced.

     

Synthesis,structure and physical properties of the one-dimensional chain complex of tetrathiafulvalene carboxylate

A new Co(II) coordination polymer bearing TTF carboxylate group, [{Co₂(trioTTF)₂(H₂O)₆}·5H₂O]_n (1) (trioTTF = 2-(5,6,8,9,11,12,14,15-octahydro-[1,3]dithiolo[4,5-h][1,4,13,7,10]trioxadithiacyclopentadecin-2-ylidene)-1,3-dithiole-4,5-dicarboxylate), has been prepared and characterized. In the structure of 1, shorter intermolecular S····S contacts (3.565 Å) are found between the trioTTF groups from neighboring chains. The electric conductivity of 1 is poor due to the bulky crown-ether group, but it exhibits ferromagnetic interaction at low temperature.