Advanced Materials Research Vols. 652-654

Abstract: A novel demultiplexing photodetector which consists of a filtering cavity and a conical absorption cavity is proposed. The filtering cavity is formed by four coupled （Fabry-Pérot）F-P cavities, which can realize flat-top and steep-edge spectral response. The top mirror of the absorption cavity is designed to be conical, which can increase the times of light reflection. Then the quantum efficiency is improved. Through the theoretical analysis and simulation, the peak quantum efficiency of the photodetector is 88.87% around 1550nm. In addition, this photodetector has good performance in the flat-top and steep-edge spectral response: the 0.5dB bandwidth is 0.4nm , the 3dB bandwidth is 0.56nm and the 20dB bandwidth is 0.98nm.

Abstract: ZnO@ZnS nano-array core-shell structure was synthesized through a solution method using a thioacetamide (TAA) solution in deionized water. The as-synthesized ZnO nano-array and TAA solution were employed to supply zinc and sulfur ions to form the ZnO@ZnS core-shell structures. The properties of the structure were characterized by X-ray diffraction (XRD), Raman spectrum, scanning electron microscopy (SEM) and UV-Vis spectra. The results indicate that ZnO nano-array was coated with ZnS particles. The concentration of TAA solution can affect the diameter, surface roughness and optical properties of the ZnO@ZnS nano-array core-shell structures.

Abstract: Combretastatins-A4 (CA-4) is a natural product with anticancer activity. However, only the cis-isomer exhibits strong antitubulin activity, but the cis-isomer tends to isomerize to the inactive trans-isomer. Thus, this paper reports that an additional pyrrolidone ring was used to replace the cis double bond to arrest the cis-conformation, and a series of 3,4-diaryl pyrrolediones and 3,4-diaryl pyrrolones as CA-4 analogues were synthesized via a four steps reaction from 3,4-dimethoxyacetophenone and 3-fluoro-4-methoxy acetophenone. The structure of the new compounds was confirmed by 1H NMR, 13C NMR, ESI-MS and elemental analysis. The in vitro activities of CA-4 analogues against HL-60, SMMC-7721 and A549 human cancer cell lines were tested using colorimetric MTT assay and the results indicate that they show significant antitumor activity.

Abstract: Titanium Silicalite-1 (TS-1) zeolite was successfully synthesized through a mechanochemical assisted processing. In this method, an amorphous silica-titania precursor was firstly prepared through a mechanochemical treatment. TS-1 was then synthesized by the hydrothermal treatment of the silica-titania precursor with tetrapropylammonium bromide (TPABr) as the template. The results of the XRD, UV-vis, and FT-IR spectrum indicated that the titanium atom was incorporated into the amorphous silica-titania precursor during the grinding, and was also retained in the final TS-1 framework after the hydrothermal treatment. SEM image showed that the TS-1 appeared in a shape of elongated prism. The catalytic performance of TS-1 was examined by phenol hydroxylation with hydrogen peroxide as the oxidant. The results indicated that TS-1 synthesized by this method exhibited a good activity.

Abstract: A series of novel coated urea, which do no harm to soil, were prepared by the method of melt atomizing coating. The coating is composed of paraffin wax, rosin and the CaHPO4 powder which used as additive. The release characteristics of the coated urea were determined by marinating in water and in soil respectively. Surface and cross-section morphology of the coated urea were studied by scanning electronic microscopy (SEM). The influences of coating content on the nitrogen release rate were discussed. The results indicate that the coating content plays a significant role in the nitrogen release. The results of release data regression show that the nitrogen release behavior of the coated urea could be characterized by the first-order release kinetics; the releasing period in water at 25 is 10.07 d for CRC-25, 17.88 d for CRC-30 when 80% nitrogen was released, respectively. And the releasing period in soil at 25 °C is over 130 d for the two coanted urea; the SEM for the coated urea show that the aperture in the membrane is less than 2 μm.

Abstract: A general kinetics equation was deduced for bifunctional polyesterification taken account of the changes of density during the reaction process. Kinetics parameters were given by using mol•L^-1 and mol•kg^-1 as the unit, respectively. The results show that the kinetic parameters expressed with mol•L^-1 are greater than those with mol•kg^-1 in the system of Neopentyi glycol/Maleic anhydride, and particularly the relative errors between them are increased along with the rise of temperatures.

Abstract: A series of mesoporous materials Sn-SBA-16 was prepared by one-step hydrothermal synthesis with F127, TEOS and SnCl4•5H2O as template, silica source and tin source, respectively, without mineral acid added. The samples were characterized by XRD, N2 sorption, TEM and UV–Vis. The acidity property of acidic sites in the surface of the samples was investigated by pyridine-absorbed FT-IR. The results indicate that the materials exhibit high surface area and uniform pore distribution. The samples contain both Lewis and Brönsted acid sites, moreover, the total concentration of both Lewis and Brönsted acid sites increases with the decrease of the ratio of Si to Sn. And Lewis acid site plays the dominate role.

Abstract: A series of supported Cu2O catalysts on Mg(OH)2 or γ-Al2O3 were prepared by coprecipitation-chemical reduction combined with impregnation using Cu(NO3)2 as precursor salt and hydrazine hydrate as the reducing agent. The crystal phase characteristics and specific suface area of the samples have been characterized by means of X-ray powder diffraction (XRD) and BET method. Catalytic dehydrogenation reaction activity of cyclohexanol over the catalysts was investigated. Results showed Cu2O is the main active component over the supported catalysts. Cu2O Grain has good dispersion in nanoscale. Acid or alkali type of the support has great influence on cyclohexanol dehydrogenation activity of supported Cu2O catalysts. There have cyclohaxene and cyclohexanone products over the supported catalysts. The reaction activity of Cu2O/ Mg(OH)2 catalysts changed with hydrazine hydrate volume. Cyclohexanol conversion and cyclohexanone selectivity can reach to 97.2% and 71.2%.

Abstract: Diethyl phthalate (DEP,CAS Registry no.84-66-2), a kind of Phthalate esters (PAEs), which was used in many industries as an important industrial material, such as plastic, painting, rubber pesticide, cosmetic, etc. In recent years, DEP has caused environmental problems all over the world for widely use. This article discussed the development toxicity of DEP in microbial and plant, rats and humans and the progress of the technologies for degradation of DEP. We proposed that evaluation of the development toxicity and degradation of DEP would be important for risk assessment in humans and the environment removal.

Abstract: The interactions of bovine serum albumin (BSA) with phosphotungstic heteropoly acid (PW), silicon tungsten heteropoly acid (SiW) and silicon tungsten-cobalt acid (SiWCo) were studied by fluorescence spectroscopy and UV absorption spectroscopy at Tris buffer solution (pH = 7.40). It was found that the fluorescence quenching of PW, SiW and SiWCo with BSA was static and the binding constant, binding site and the thermodynamic parameters were calculated at 298 and 310K. In addition, the conformations of BSA impacted by PW, SiW and SiWCo were researched using synchronous fluorescence. The results showed that PW, SiW and SiWCo all could interact with BSA but they had not changed the conformation of BSA.