Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
An intense green upconversion emission due to a photon avalanche mechanism has been observed in Ho3+–Yb3+ codoped fluroindate glasses, measured at 200 K, under excitation at around 750 nm. The influence of the Yb3+ concentration on the photon avalanche process has been studied. The pump power threshold of the avalanch…
Cyclic peptides with alternating d- and l-amino acid residues containing tert-leucine residues in every second position can form peptide nanotubes only when both enantiomers of the peptide are present in the solution. These results strongly indicate the formation of peptide nanotubes that assemble with one enantiomer…
In this article we present an alternative approach for the fabrication of silicon nanocrystals (Si–nc) prepared ex situ of the silicon dioxide (SiO2) host matrix. The Si–nc are scratched from porous silicon layers and incorporated into a host spin-on-glass SiO2 based matrix. High-resolution transmission electron micro…
Controlled grafting of polybetaine brushes onto hydrogen-terminated Si(100) substrates (Si−H substrates) was carried out via surface-initiated reversible addition−fragmentation chain-transfer (RAFT) polymerization. The azo initiator was immobilized on the Si−H surface through a three-step process: (i) coupling of an ω…
A fluid of hard spherocylinders of length-to-breadth ratio L/D=5 confined between two identical planar, parallel walls--forming a pore of slit geometry--has been studied using a version of the Onsager density-functional theory. The walls impose an exclusion boundary condition over the particle's centers of mass, while…
The electron spin polarization associated with electronic relaxation in molecules with trip-quartet and trip-doublet excited states is calculated. Such molecules typically relax to the lowest trip-quartet state via intersystem crossing from the trip doublet, and it is shown that when spin-orbit coupling provides the m…
Large-scale Y2O3:Eu nanotubes have been successfully fabricated by an improved sol–gel method within the nanochannels of porous anodic alumina templates. In this method, yttrium nitrate, europium nitrate and urea were used as precursors, yttrium nitrate and europium nitrate were acting as sources of europium and yttri…
The temperature dependence of the current conduction mechanisms in Au/Pb(Zr0.53,Ti0.47)O3/Pt (Au/PZT/Pt) metal–insulator–metal thin-film capacitors was investigated. The dominant current conduction mechanism from 300 to 375 K is space-charge-limited current (SCLC) due to holes and changes to Schottky emission in the t…
Adsorption isotherms of aromatic BTX (benzene, toluene, and p -xylene) hydrocarbons on pure and Ag-doped SiO 2 microporous substrates synthesized by the sol−gel procedure have been measured by the gas chromatographic technique at several temperatures in the range between 423 and 573 K. Both Langmuir and Dubinin adsorp…
The composition dependence and orientation anisotropy of the dielectric and ferroelectric properties of epitaxial Pb(ZrxTi1−x)O3 (PZT) thin films grown using metalorganic chemical vapor deposition were investigated. {100}-, {110}-, and {111}-oriented PZT films were ascertained to have been grown on (100)c, (110)c, and…
Electrostatics plays a major role in heat adaptation by thermophilic proteins. Here we ask whether electrostatics similarly contributes to cold adaptation in psychrophilic proteins. We compare the sequences and structures of citrate synthases from the psychrophile Arthobacter Ds2-3R, from chicken, and from the hyperth…
Er 3+ -doped halide modified tellurite glasses were synthesized by conventional melting and quenching method. The Judd–Ofelt analysis was performed on the absorption spectra and the transition probabilities, excited state lifetimes, and the branching ratios were calculated and discussed. The intense infrared and visib…
Dielectric relaxation measurements of a typical small molecular glassformer, dipropyleneglycol dibenzoate show the presence of two secondary relaxations. Their dynamic properties differ in the equilibrium liquid and glassy states, as well as the changes during structural recovery after rapid quenching the liquid to fo…
We have developed techniques for the efficient synthesis and screening of small libraries of surface-functionalized nanoparticles for the recognition of specific types of cells. To illustrate this concept we describe the development of a nanoparticle that preferentially recognizes apoptotic Jurkat cells in a manner si…
We found that the conventional model of orbital-ordering of $3{x}^{2}\ensuremath{-}{r}^{2}/3{y}^{2}\ensuremath{-}{r}^{2}$ type in the ${e}_{g}$ states of ${\mathrm{L}\mathrm{a}}_{0.5}{\mathrm{S}\mathrm{r}}_{1.5}{\mathrm{M}\mathrm{n}\mathrm{O}}_{4}$ is incompatible with measurements of linear dichroism in the Mn $2p$-e…
A novel size dependence in the adsorption reaction of multiple O2 molecules onto anionic silver clusters Agn- (n = 1-5) is revealed by gas-phase reaction studies in an rf-ion trap. Ab initio theoretical modeling based on DFT method provides insight into the reaction mechanism and finds cooperative electronic and struc…
Decomplexation of the trivalent lanthanide, Ln(III), from the racemic bimetallic triple-stranded helicates [LnCr(L8)(3)](6+) provides the inert chiral tripodal nonadentate receptor [Cr(L8)(3)](3+). Elution of the latter podand with Na(2)Sb(2)[(+)-C(4)O(6)H(2)](2).5H(2)O through a cation exchange column allows its sepa…
Gold glyconanoparticles (GNPs) have been prepared as new multivalent tools that mimic glycosphingolipids on the cell surface. GNPs are highly soluble under physiological conditions, stable against enzymatic degradation and nontoxic. Thereby GNPs open up a novel promising multivalent platform for biological application…
The dielectric property complemented by the mechanical measurement (internal friction) in the doped Bi4Ti3O12 [Bi4−xLaxTi3O12 (x=0.5,0.75,1) and Bi4−y/3Ti3−yNbyO12 (y=0.015,0.03,0.06)] was systematically investigated from room temperature to 350 °C. In the plot of dielectric loss versus temperature for Bi4Ti3O12 (BiT)…
A reentrant novel phase is observed in the hexagonal ferroelectric HoMnO3 in the presence of magnetic fields in the temperature range defined by a plateau of the dielectric constant anomaly. The plateau evolves with fields from a narrow dielectric peak at the Mn-spin rotation transition at 32.8 K in zero field. The an…