The character of W-doped one-dimensional VO2 (M)

The one-dimensional W-doped VO₂ (M) solid solutions with a various doped content were successfully synthesized under hydrothermal condition and subsequent calcination for the first time, and physical-chemical and phase transformation character were explored, subsequently. DSC analyses displayed that the phase-transition temperature of VO₂ (M) solid solution could be linearly tuned with the doped content. Promisingly, the one-dimensional W-doped VO₂ (M) had a good thermochromic property.     

Syntheses, crystal and electronic structures of three new potassium cadmium(II)/zinc(II) tellurides: K2Cd2Te3, K6CdTe4 and K2ZnTe2

Three new ternary potassium(I) zinc(II) or cadmium(II) tellurides, namely, K₂Cd₂Te₃, K₆CdTe₄ and K₂ZnTe₂, were synthesized by solid-state reactions of the mixture of pure elements of K, Cd (or Zn) and Te in Nb tubes at high temperature. K₂Cd₂Te₃ belongs to a new structure type and its structure contains a novel two-dimensional [Cd₂Te₃]²⁻ layers perpendicular to the b-axis. K(5) cation is located at the center of five member rings of the 2D [Cd₂Te₃]²⁻ layer, whereas other K⁺ cations occupy the interlayer space. K₆CdTe₄ with a K₆HgS₄ type structure features a “zero-dimensional” structure composed of isolated CdTe₄ tetrahedra separated by the K⁺ ions. K₂ZnTe₂ in the K₂ZnO₂ structural type displays 1D [ZnTe₂]²⁻ anionic chains of edge sharing [ZnTe₄] tetrahedra separated by the potassium(I) ions. K₂Cd₂Te₃, K₆CdTe₄ and K₂ZnTe₂ revealed a band gap of 1.93, 2.51 and 3.0 eV, respectively.     

Hydrogen peroxide sensor based on horseradish peroxidase immobilized on an electrode modified with DNA-L-cysteine-gold-platinum nanoparticles in polypyrrole film

A third-generation mediator-free hydrogen peroxide biosensor was fabricated by combining electrodeposition and self-assembly techniques. In this strategy, Au-Pt hybrid nanoparticles were electrodeposited on a film of polypyrrole, and L-cysteine was assembled to their surface by exploiting the strong affinity between mercapto groups and nanoparticles. Then, DNA and horseradish peroxidase were respectively self-assembled on the surface of the electrode. The resulting electrode was characterized by impedance spectroscopy, and the electrode surface (without enzyme) was characterized by scanning electron microscopy. The response of the sensor towards hydrogen peroxide, as investigated by cyclic voltammetry and chronoamperometry, is linear between 4.9 µM to 4.8 mM, with a detection limit of 1.3 µM (at an S/N of 3). The apparent Michaelis-Menten constant $ \left( {K_M^{app}} \right) $ is 0.69 mM.     

Ferrocene clicked poly(3,4-ethylenedioxythiophene) conducting polymer: Characterization, electrochemical and electrochromic properties

The “click” chemistry, Cu(I)-catalyzed azide–alkyne cycloaddition reaction, was applied to covalently functionalize the poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer film with an excellent electron transfer mediator (ferrocene). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy were used to characterize the ferrocene-grafted PEDOT conducting polymer film, and it was proved that the grafting procedure via click reaction had a high efficiency. The ferrocene groups covalently grafted in the polymer films turned out to own a relatively fast electron transfer rate and show multi-color states via adjusting applied potential.     

Covalent grafting nitrophenyl group on Au surface via click reaction: Assembling process and electrochemical behaviors

In this paper, we described a simple and facile method for the covalent functionalization of Au surface with nitrophenyl group via stepwise strategy. Structurally well-defined azide-terminated organic self-assembled monolayers (SAMs) were formed on Au surface from a commercially available mixture solution of azidoundecanethiol and dilute thiol. Subsequent, derivatization of the azide-terminated monolayers was conducted in aqueous environments with ethynyl nitrobenzene via a selective, reliable, robust click reaction. By this way, the nitrophenyl group was covalently and quantitatively grafted on Au surface, which was confirmed by Raman Spectrometry and electrochemical methods. These results demonstrated the efficiency of using click chemistry in assembling covalently linked nanostructures.     

Double Layer of Au(100)/Ionic Liquid Interface and Its Stability in Imidazolium‐Based Ionic Liquids

Ring any bells? The differential capacitance curve of Au(100) in neat [BMI]BF₄ (BMI=1‐butyl‐3‐methylimidazolium) ionic liquid has a bell‐shaped feature (see picture). The adsorption of BMI⁺ shows a disorder–order transition and depends on the structure of the surface. Ordered adsorption in a micelle‐like structure stabilizes the underlying Au surface.

     

Hydrogen‐Bond‐Selective Phase Transfer of Nanoparticles across Liquid/Gel Interfaces

In the swim : Colloidal nanoparticles coated with polylactide (PLA, red) and poly(ethylene glycol) brushes (PEG, black) can transfer from organic to aqueous phases across liquid/liquid or liquid/gel interfaces during degradation of the PLA coating (see picture: first step), which is driven selectively by the hydrogen bonding of the PEG coating with the aqueous phase (second step).

     

Metabonomics studies of intact hepatic and renal cortical tissues from diabetic db/db mice using high-resolution magic-angle spinning 1H NMR spectroscopy

A metabonomics approach based on high-resolution magic-angle spinning (HRMAS) ¹H NMR spectroscopy was applied to investigate the metabolite composition in intact hepatic tissues and renal cortical tissues from db/db mice of 8 weeks old, an animal model of type 2 diabetes mellitus. Compared to the control group, the hepatic tissues of diabetic mice have elevated levels of triglyceride and bile acid and declined levels of trimethylamine-N-oxide, phosphocholine, glycerophosphocholine, and choline. The biochemical changes are less obvious in renal cortical tissues of diabetic mice. The WET_CPMG pulse sequence was selected for our metabonomics study after the quality and reproducibility of the spectra obtained from the NOEPR, NOEPR_CPMG, and WET_CPMG pulse sequences were analyzed together with principal component analysis. The influence of line-broadening factor of exponential window function for spectral manipulation on class separation was paid attention to for the first time, and an optimal value was obtained under our experimental conditions. These studies show the efficiency of HRMAS ¹H NMR spectroscopy for tissue metabonomics study in combination with multivariate statistical analysis, which may help to explore the etiological factor of diabetes mellitus from a new perspective.

Lattice orders on 2 × 2 triangular matrix algebras

We construct all the lattice orders on a 2 × 2 triangular matrix algebra over a totally ordered field that make it into a lattice-ordered algebra. It is shown that every lattice order in which the identity matrix is not positive may be obtained from a lattice order in which the identity matrix is positive.     

LYAPOUNOV EXPONENTS AND LAW OF LARGE NUMBERS FOR RANDOM WALK IN RANDOM ENVIRONMENT WITH HOLDING TIMES

In this article, the authors mainly discuss the law of large number under Kalikow＇s condition for multi-dimensional random walks in random environment with holding times. The authors give an expression to the escape speed of random walks in terms of the Lyapounov exponents, which have been precisely used in the context of large deviation.