New glass-ceramic sealants for Na/S battery

The sodium sulfur (Na/S) battery is one of the most promising candidates for energy storage applications developed since the 1980s. However, the seal between the alpha-alumina and beta-alumina in the Na/S battery presents a challenge. In this work, the new glass-ceramic sealants for the Na/S battery have been developed. The borosilicate glass was chosen as the basic glass and TiO₂ as the nucleating agent. The sintering behavior was evaluated by the shrinkage curves and the densities of the sintered samples. The sintering temperature of 750 °C was obtained. The thermal expansion coefficient (TEC) of the glass-ceramic sealants matched well with that of the alpha-alumina and beta-alumina. The thermal shock resistance and chemical stability of the sealants were also satisfactory. No microcracking was observed in the sealants after thermal shock for 100 times. The diffusion layer of about 10 μm was found between the glass and the substrate after 850 h. However, the densification of the sealants remained to be further improved. The factors influencing the densification of the sealants were clarified, and the possible solving means were proposed.     

Controlled aggregation of functionalized gold nanoparticles with a novel conjugated oligomer.

A new route is developed to control the self-assembly of gold nanoparticles (AuNPs) functionalized with a novel pyridyl-ended porphyrin-oligo(p-phenylene vinylene) conjugated oligomer (P-OPV-Py) into branched-rods, chain-networks, uniform fractal-like Au clusters, and larger nanoparticles. The techniques of optical spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) are used to characterize the self-assembly in various solvent systems (pure toluene, CHCl(3)/toluene, THF/toluene and n-butanol/toluene). A combination of the ligand/AuNPs molar ratio and relative concentration serves as the driving force to control the size and shape of P-OPV-Py capped AuNPs.     

Novel probes based on coumarin-bisdithiocarbamate system for selective recognition of Ag(I) in aqueous solution

Research on Chemical Intermediates - Two novel fluorescent probes (C1, C2), comprising a coumarin moiety as fluorophore and a pair of dithiocarbamates as recognition sites, were designed and...     

Hierarchical porous CoMn<Subscript>2</Subscript>O<Subscript>4</Subscript> microspheres with sub-nanoparticles as advanced anode for high<Emphasis Type="Bold">-</Emphasis>performance lithium<Emphasis Type="Bold">-</Emphasis>ion batteries

To deal with the large volume change for lithium-ion batteries (LIBs), we illustrate the synthesis of CoMn₂O₄ microspheres with sub-nanoparticles by a hydrothermal method followed by thermal treatment. The size of microsphere is approximately 2.2 μm, and the sub-nanoparticle is about 17 nm. There is sufficient void space between CoMn₂O₄ microspheres with sub-nanoparticles for ensuring the well structural integrity. As advanced anode for LIBs, CoMn₂O₄ microspheres display stable specific capacity retention of 772 mAh g^?1 over 500 cycles at a current density of 100 mA g^?1. Such a kind of structure is beneficial for enhanced rate and cycling capabilities in LIBs applications, which could increase contact area between electrolyte and active materials, short path for lithium ions and electrons and accommodate the volume change with additional void space during cycling. It has a great application prospect for use as electrochemical energy storage because of the enhanced performance.     

Smooth Approximations and Exact Solutions of the 3D Steady Axisymmetric Euler Equations

In this paper, we prove that a class of C ¹-smooth approximate solutions {u ^ε, p ^ε} to the 3D steady axisymmetric Euler equations will converge strongly to 0 in . The main assumptions are that the approximate solutions have uniformly finite energy and approach a constant state at far fields. We also show a Liouville type theorem that there are no non-trivial C ¹-smooth exact solutions with finite energy and uniform constant state at far fields. The research is partially supported by National Natural Sciences Foundation of China (No. 10871133 & No. 10771177). The research is partially supported by Zheng Ge Ru Funds, Hong Kong RGC Emarked Research Grant CUHK4028/04P and CUHK4040/06P, RGC Central Allocation Grant CA 05/06. SC01, and a grant from Northwest University, Xi’an, PRC.     

自极化效应对稀土掺杂聚合物激发和发射光谱的影响

合成并用FT IR和元素分析方法表征了Eu(DBM) 3·Phen .对不同浓度的稀土络合物溶液和掺杂聚合物的激发光谱和发射光谱进行了测定和研究 ,结果发现在溶液和固体介质中都存在着溶质间的相互作用 .这种自极化相互作用影响包括两个方面 :有机配体的吸收光谱出现红移现象 ;稀土离子的对称性的变化 .自极化相互作用导致分子内的电荷分布变化 ,改变了激发态和基态间的能量 ,激发光谱出现红移 .在低浓度时 ,介质的性质对红移影响较大 ,高浓度时 ,介质的影响变小 .还讨论了各种因素对稀土掺杂体系的荧光性质的影响     

Multi‐dimensional Copper(II) Coordination Polymers via Self‐assembly Induced by Sodium Ions

Two novel copper(II) coordination polymers, [CuNa₂(Hnta)₂]_n ( 1 ) and {[CuNa₂(pht)₂(H₂O)]·H₂O}_n ( 2 ) (H₃nta = nitrilotriacetate acid, H₂pht = o‐phthalic acid), have been synthesized and characterized.The sodium ions play an important role in the formation of the multi‐dimensional structures. The X‐ray structure of [CuNa₂(Hnta)₂]_n ( 1 ) is three‐dimensionally cross‐linked with building blocks [Cu(Hnta)₂]^2—connected by three sodium ions. The structure of {[CuNa₂(pht)₂(H₂O)]·H₂O}_n ( 2 ) can be described as pht units connected by Na ions via Na—O bonds to form chains, which are linked by Cu^II ions to make a 2D network. The IR spectra and thermal properties are also reported.     

The Synthesis and Activity in vitro of a Series of 5-Amino-8-methoxyquinolones

A series of 1-cyclopropyl-5-amino-6-fluoro-8-methoxyquinoline-3-carboxylic acids have been prepared and evaluated for antibacterial activity in vitro.     

Preparation of La-Ti Composite Oxide Nanocrystal and Examination of Their Surface Topography with Atomic Force Microscope

Atomic force microscope (AFM) is a kind of scanning probe microscope (SPM) derived from scanning tunnel microscope (SCM)1,2. Enjoying such advantages as simple preparation of sample and nanometric differentiation scale 3, AFM is greatly welcome in chemistry, material and biology science research4~7. Composite oxides containing rare-earth element and transitional metal such as titanium as the third element enjoy many promising applications owning to their excellent physical and chemical pr…