Advanced Materials Research Vol. 852

Abstract: The present paper reports a novel solution to develop a calcium phosphates (CaPs) coating with an anodic nanotubular TiO₂ layer on titanium screw by electrochemical disposition (ECD). The elemental composition of coatings was examined by energy dispersive spectroscopy (EDS), the surface mopholoy was characterized with scanning electron microscopy (SEM), and the functional groups and crystalline phase were analyzed using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Furthermore, the bioactivity was tested by immersion in simulated body fluid (SBF) for 7 days. The results showed that a nanotubular TiO₂ layer was established which has about 100 mm diameter and the calcium phosphate coatings have higher bioactivity and porosity compared with uncoated titanium screws, which make the coating more conductive to cell adhesion. Using alkaline treatment, the calcium phosphate coating could transform into hydroxyapatite (HAp), making the coating closer to the biological complement. This provides a valuable tool for biomedical applications.

Abstract: An environment-friendly plasticizer, epoxidized corn oil was prepared by the epoxidation of corn oil with peroxyacetic acid which was generated in situ from hydrogen peroxide and glacial acetic using acidic ion exchange resin modified by zinc chloride as catalyst. The product with an epoxy oxygen content of 6.40 w% and a percent conversion to oxirane of 87.67 % was obtained under the following optimized conditions: 15 % modified ion exchange resin feed relative to the weight of corn oil, the molar ratio of 1.7 to 1 with hydrogen peroxide to double bonds, 18% acetic acid feed relative to the weight of corn oil, the reaction time of 5.5 h, the temperature of 75 °C and stirring speed of 600 rpm.

Abstract: Using microwave technology,establish a best destroying enzyme condition that can make peroxidase (POD) and polyphenoloxidase (PPO) lossing of activity. Enzyme activity of PPO and POD were determined by guaiacol colorimetric method and catechol colorimetric method under the condition of six different microwave time and five different microwave power. Complete deactivation of POD and PPO was achieved when microwave treatment of the chestnut kernel to 640W/60s were combined. Under these conditions, the color and flavor of the product were retained,which is the best destroying enzyme condition in chestnuts by microwave heating

Abstract: The conditions for detecting residues of diflubenzuron in vegetables by ultra high performance liquid chromatography tandem mass spectrometry were studied. The target was extracted with acetonitrile for 2 min with a homogenizer. The extaction was purifide by a conditioned Florisil SPE cartridge, and then was detected by ultra high-performance liquid chromatography with tandem mass spectrometry. The average recovery was in the range from 87.8 %- 99.2 % at spike levels of 0.1, 1.0 and 10 mg/kg in vegetables, and relative standard deviations was in the range of 4.2 %-8.9 %. The proposed method is fast, simple, sensitive and accurate.

Abstract: Residual amount of chlorbenzuron derived from tea was determined by UPLC-MS/MS. Chlorbenzuron was extracted with acetonitrile, purified by carbon/NH₂ SPE cartridge, and then determined by ultra high-performance liquid chromatography with tandem mass spectrometry. The values o f lower limit of determination (10 S/ N) of 1.0 ug/kg^-1 was found for Chlorbenzuron.Linear relationships in the range within 200 ug/L^-1 was found . Recovery and precision of the method was tested by standard addition method at 3 concent ration levels. Results obtained was as follows: recovery 79.2 % - 89.6 %; RSD ( n= 6) of repeatability 0.72 % -5.85 %.It is suitable for the determination of chlorbenzuron residual in tea.

Abstract: A method for determination of imidacloprid in Chinese Cabbage was established by using UPLCMS/MS. and the samples are extracted with acetontrile,and the extract is cleaned up by Florisil SPE cartridges and evaporated.Choromatographic separation was performed on a C18 column,and determined by UPLC-MS/MS.The external standard calibration curves were used for quantification. The results showed that a good linear correlation was obtained in the range of 0.005-0.1ug/mL. The limit of quantif icat ion w as 0. 008 mg/ kg .The average recoveries and the relative standard deviations were in the range of 84.9 %~92.7 % and 0.9 %~6.2 %, respectively. It is applicable to the determination of imidacloprid redidue in Chinese cabbage.

Abstract: Four flavonoids were isolated from the EtOAc extract of Gentiana algida Pall. The structures of these compounds were elucidated as: patulitrin (1), Isoscoparin (2), swertisin (3), swertiajaponin (4). These compounds were identified on the basis of comparing their NMR datas with those of corresponding compounds in the literature. The cytotoxic activity of all these compounds were investigated on the growth of HepG-2 cells, the result showed that compound 2 have high cytotoxic activity, the IC₅₀ value is 47.25g/ml.

Abstract: Multilayer ZnO varistors were prepared by aqueous gel tape casting with water-soluble acrylamide as binder. 0.8wt% PAA dispersant was found to be the optimum concentration needed to prepare stable slurry. Plasticizer glycerol has a positive effect on the fluidity of the suspension and oxygen anti-polymerizing inhibitor PEG 2000 deteriorated the fluidity. The addition of 15wt. % PEG2000 eliminates the surface exfoliation absolutely due to the oxygenation of ether units. The solid loading of the slurry was about 71wt% compared to the custom acrylic formulation binder 60wt%. The multilayer ZnO varistors prepared by aqueous gel tape casting display comparable good electrical properties to those prepared by water-based tape casting using custom acrylic formulation binder which is attributed to the high solid loading of slurry.

Abstract: In recent years, MgZnO alloy becomes one of the most suitable materials for the fabrication of ultraviolet detectors. In this paper, we have fabricated three metal semiconductor metal (MSM) photodetectors on Mg_0.42Zn_0.58O film grown by radio frequency magnetron sputtering. The interdigital electrodes are 500 um long and 5 um wide with an interelectrode spacing 2, 5 and 10 um, respectively. The structural, electrical and optical properties of epilayers were characterized by various techniques. At 5 V bias, a peak responsivity of 1.09 mA/W was achieved at 283 nm for the device with 2 um interelectrode spacing. The peak responsivity at 283 nm increased with the reduction of the finger pitch for three devices and the ultraviolet-visible rejection ratio (R283 nm/R400 nm) was more than one order of magnitude at 5 V bias.

Abstract: A distributed feedback (DFB)-laser-based micro-accelerometer is proposed and experimentally demonstrated. The results show that it is characteristic of higher precision than the piezoelectric vibrator. A minimum signal of 9.11×10-4g at 130Hz is acquired.