硝酸镧处理对微弧氧化二氧化钛膜光催化性能的影响

以磷酸钠为电解液,采用交流微弧氧化技术在钛网上直接制备TiO2膜,利用硝酸镧浸渍方法对该膜进行表面处理,以酸性大红染料模拟废水来评价TiO2膜光催化水中有机污染物的能力。利用X射线衍射仪、SEM和EDX对微弧氧化膜晶型、表面形貌和成分进行分析。结果表明:微弧氧化TiO2膜主要由锐钛矿TiO2组成,由于膜表面钠离子的沉积,微弧氧化TiO2膜的光催化性能较差;硝酸镧浸渍处理可以减少微弧氧化TiO2膜表面钠离子含量,改善膜的光催化性能,120min酸性大红染料废水的光催化脱色率由15%提高到34.8%以上。     

Novel Brønsted acid catalyzed three-component alkylations of indoles with N-phenylselenophthalimide and styrenes

Novel and efficient Br?nsted acid (p-TsOH) catalyzed inter- and intramolecular Friedel-Crafts alkylations have been developed to synthesize selenated three-component coupling and selenation-cyclization indole derivatives. Chemical removal of the phenylseleno moiety was investigated, and the reaction mechanisms were discussed.     

Application of NaClO-treated multiwalled carbon nanotubes as solid phase extraction sorbents for preconcentration of trace 2,4-dichlorophenoxyacetic acid in aqueous samples

Multiwalled carbon nanotubes functionalized by oxidation of original multiwalled carbon nanotubes with NaClO were prepared and their application as solid phase extraction sorbent for 2,4-dichlorophenoxyacetic acid (2,4-D) was investigated systemically, and a new method was developed for the determination of trace 2,4-D in water samples based on extraction and preconcentration of 2,4-D with solid phase extraction columns packed with NaClO-treated multiwalled carbon nanotubes prior to its determination by HPLC. The optimum experimental parameters for preconcentration of 2,4-D, including the column activating conditions, the amount of the sorbent, pH of the sample, elution composition, and elution volume, were investigated. The results indicated 2,4-D could be quantitatively retained by 100 mg NaClO-treated multiwalled carbon nanotubes at pH 5, and then eluted completely with 10 mL 3:1 (v/v) methanol-ammonium acetate solution (0.3 mol/L). The detection limit of this method for 2,4-D was 0.15 μg/L, and the relative standard deviation was 2.3% for fortified tap water samples and 2.5% for fortified riverine water sample at the 10 μg/L level. The method was validated using fortified tap water and riverine water samples with known amount of 2,4-D at the 0.4, 10, and 30 μg/L levels, respectively.     

Ultraviolet Light Assisted Hierarchical Porous Fe2O3 Catalyzing Heterogeneous Fenton Degradation of Tetracycline Under Neutral Condition with a Low Requirement of H2O2

The hierarchical porous Fe2O3 particles as a novel ultraviolet light assisted heterogeneous Fenton catalysts were synthesized by bio-template synthesis method using iron nitrate as precursor at high temperature of around 550℃.The hierarchical porous structured Fe2O3 was endowed with a large surface area and abundant pore volume,leading to the exposure of more active sites and rapid mass transfer.The synergistic effect of UV irradiation and hie-rarchical porous Fe2O3 improved the photo-degradation efficiency of Tetracycline(TC).The degradation efficiency of Fe203 catalyzing UV-Fenton system reached 97.4%after 60 min reaction,which was more substantial than Fe2O3 catalyzing Fenton system(7.6%)and UV/H2O2 system(59.2%).Moreover,the hierarchical porous Fe2O3 catalyzing UV-Fenton system exhibited an extremely wide pH range(from 3.0 to 9.0,from mildly acidic to slightly alkaline)for efficient degradation of TC.Simultaneously,the extraordinary higher degradation efficiency was based on 10 mmol/L H2O2 concentration,which was low requirement for H2O2,Further,the hierarchical porous Fe2O3 can be used for five consecutive cycles with over 95%of the original degradation efficiency.Ultraviolet light assisted heterogeneous Fenton reaction in the hierarchical porous Fe2O3 improved the·OH and O2·^-production and Fe(III)/Fe(II)redox cycle,which consequently achieved an excellent degradation rate.     

Yb:Y3Al5O12/Y3Al5O12复合晶体的制作和光谱性能

采用热键合技术,制作中运用不同的工艺参量制作出12片Yb:Y3Al5O12/Y3Al5O12(Yb:YAG/YAG)复合.晶体.利用偏光显微镜对其键合界面进行了观察,研究了样品的透射光谱,从而确定出复合晶体合适的制作工艺.通过透射光谱的形状和透射率来表征复合晶体键合界面的质量.研究表明Yb:YAG/YAG复合晶体键合质量较好,可实现一体化.     

Combination of dispersive solid‐phase extraction and salting‐out homogeneous liquid–liquid extraction for the determination of organophosphorus pesticides in cereal grains

A new analytical method for the determination of organophosphorus pesticides in cereal samples was developed by combining dispersive SPE (d‐SPE) and salting‐out homogeneous liquid–liquid extraction (SHLLE). The pesticides were first extracted from cereal grains with acetonitrile, followed by d‐SPE cleanup. A 2 mL aliquot of the extract was then added to a centrifuge tube containing 9.2 mL water and 3.3 g NaCl for SHLLE. Analysis of the extract was carried out by gas chromatography coupled with flame photometric detection. The d‐SPE procedure effectively provides the necessary cleanup of the extract while SHLLE is used as an efficient concentration technique. Experimental parameters influencing the extraction efficiency including amounts of added water and salt were investigated. Recovery studies were carried out at three fortification levels, yielding recoveries in the range of 57.7–98.1% with the RSD from 3.7 to 10.9%. The reported limits of determination obtained from this study were 1 μg/kg, which is better than the conventional methods. In the analysis of 40 wheat and corn samples taken from Beijing suburbs, only two wheat samples have chlorpyrifos residue over the limits of determination.     

Toxicology Assessment of a Dual-Function Peptide 5rolGLP-HV in Mice

5rolGLP-HV had an ideal therapeutic potential in the prevention of hyperglycemia in type 2 diabetes and delay of the thrombosis. The objective of the study was to investigate the toxicology effects of 5rolGLP-HV and guarantee its safety. In acute toxicity test, the mice were orally receiving 5rolGLP-HV at a single dose of 300 mg/kg or 2000 mg/kg. For sub-chronic toxicity study, the mice received 5rolGLP-HV at doses of 800 mg/kg or 1600 mg/kg for 9 weeks. No significant adverse effects were evident in acute and sub-chronic toxicity tests, indicating that the LD50 value is greater than 2000 mg/kg. Although the liver and kidney exhibited a little abnormal in sub-chronic toxicity study, they could recovery to normal after withdrawal 5rolGLP-HV for 2 weeks. In micronucleus assay, the mice received 5rolGLP-HV at doses of 250, 500, or 1000 mg/kg for two consecutive days. The micronucleus numbers and the polychromatic erythrocytes to normochromatic erythrocytes (PCE/NCE) ratios among 5rolGLP-HV groups were within the normal range. Similarly, sperm aberration test demonstrated that 5rolGLP-HV had no teratogenic effect on the mice sperm. In conclusion, the combined results clearly demonstrated the safety of 5rolGLP-HV and support its use as a drug to treat diabetes and thrombosis.     

Erratum to “Fully automated sample treatment method for high throughput proteome analysis”

Science China Chemistry -     

Synthesis and photopolymerization of piperonylamine derivatives as a polymerizable cyclic acetals co‐initiator for light‐cured unfilled dental resins

The aim of this study was to synthesize and characterize N,N‐di(methacryly‐ethoxycarbonyl‐ethyl)‐N‐(1,3‐benzodioxole‐ 5‐methylene)(DMEBM) to replace both triethylene glycol dimethylacrylate(TEGDMA) as a dilute and the non‐polymerizable amine, which is added as a co‐initiator in dental resin mixtures. 2,2‐bis[4‐(2‐Hydroxy‐3‐methacryloxypropoxy) phenyl]‐propane (Bis‐GMA) and camphorquinone (CQ) were used as monomer and photoinitiator in these model dental resin systems, in contrast to ethyl 4‐dimethylaminobenzoate (EDMAB) which was usually used as a co‐initiator. DMEBM was synthesized via Michael‐Addition reaction and characterized using ¹H NMR spectroscopy. A mixture of Bis‐GMA/DMEBM/CQ was found to reach the double bond conversion of 67.5%, slightly higher than that of Bis‐GMA/TEGDMA/CQ/EDMAB (66.8%) and Bis‐GMA/TEGDMA/CQ/DMEBM (64.8%). In addition, the glass transition temperature of Bis‐GMA/TEGDMA/CQ/EDMAB (93.4°C) were higher than that of Bis‐GMA/TEGDMA/CQ/DMEBM (89.3 °C) and Bis‐GMA/DMEBM/CQ (80.4°C). The water sorption and solubility of Bis‐GMA/TEGDMA/CQ/DMEBM were higher than that of Bis‐GMA/TEGDMA/CQ/EDMAB and Bis‐GMA/DMEBM/CQ. However, the values were still within the range of the ISO 4049 standards. DMEBM could be used as a potential co‐initiator and diluent for dental composite. Copyright © 2009 John Wiley & Sons, Ltd.