Preparation of AgBiVMoO/-Al2O3 Catalysts for the Partial Oxidation of Propane

A novel mixed sol method was developed for the preparation of supported catalysts. Analyses by means of XRD and BET show that a 40%AgBiVMoO/γ-Al2O3 catalyst prepared by this method possessed high specific surface area and high dispersion of the active phase. As a result, high acrylic acid selectivity of 8.5% was obtained when the catalyst was used in the reaction of propane partial oxidation to acrylic acid in a fixed-bed reactor.     

Self-assembly and characterization of paclitaxel-loaded N-octyl-O-sulfate chitosan micellar system

N-octyl-O-sulfate chitosan micellar system loaded paclitaxel was prepared by using dialysis method. The critical micelle concentration (CMC) of the modified chitosan was found to be 0.45 mg/ml. Compared with the amount of N-octyl-O-sulfate chitosan, the paclitaxel loading amount in the system was up to 25% (w/w), depending on both of the solvents used in dialysis and the feed weight ratio of paclitaxel to the derivative. The polymeric micelles forming and loading occurred simultaneously in the dialysis process when ethanol and water were utilized as the solvents for paclitaxel and the polymer, respectively. Paclitaxel-loaded micellar system of N-octyl-O-sulfate chitosan was characterized by DSC, WXRD and TEM. TEM photograph revealed that paclitaxel existed as the colloid particulates in ethanol before loading and in the cores of the spherical polymeric micelles after loading. The results of DSC and WXRD indicated that paclitaxel was transferred from the crystalline state to amorphous state after loading. The lyophilized powder of micellar system (25% (w/w) loading) could be reconstituted easily in aqueous media even after 2 months storage at 4 degrees C without the change of paclitaxel entrapment and micelle size. The reconstituted solution (2.1 mg paclitaxel/ml) also showed good stability. The dilution with saline may decrease the loading and physical stability based on the dilution times which was related with CMC of the polymer. In vitro tests showed that paclitaxel was slowly released from micellar solution and the release lasted up to 220 h by means of the dialysis method.     

人造芥子油中异硫氰酸烯丙酯与硫氰酸烯丙酯的气相色谱分析

采用２ｍ×３ｍｍ玻璃柱，涂布０．５％ＥＧＡ的８０～１００目ＧａｓｃｈｒｏｍＱ为固定相，以异辛醇为内标物，分析芥子油中异硫氰酸烯丙酯与硫氰酸烯丙酯异构体。该方法既可用于人造芥子油的含量分析，也可用于市售芥子油的质量鉴定。     

网络智能化推进网络融合

网络智能化的基本原理是在现有固定电话网中引入用户数据库（DB）新网元,国内网络智能化主要采用TDM汇接局访问DB和端局完全访问DB方式,通过软交换实现将更有优势,而未来融合的网络将引入IMS架构.     

A novel molecularly imprinted method with computational simulation for the affinity isolation and knockout of baicalein from Scutellaria baicalensis

A novel molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization with baicalein (BAI) as the template and used as solid‐phase extraction (SPE) adsorbent, aiming at the affinity isolation and selective knockout of BAI from Scutellaria baicalensis Georgi (SB). We used computational simulation to predict the optimal functional monomer, polymerization solvent and molar ratio of template to functional monomer. Characterization and performance tests revealed that MIP exhibited uniform spherical morphology, rapid binding kinetics, and higher adsorption capacity for BAI compared with nonimprinted polymer (NIP). The application of MIP in SPE coupled with high‐performance liquid chromatography to extract BAI from SB showed excellent recovery (94.3%) and purity (97.0%). Not only the single BAI compound, but also the BAI‐removed SB extract was obtained by one‐step process. This new method is useful for isolation and knockout of key bioactive compounds from herbal medicines. Copyright © 2015 John Wiley & Sons, Ltd.     

Overexpression of the Formaldehyde Dehydrogenase Gene from Brevibacillus brevis to Enhance Formaldehyde Tolerance and Detoxification of Tobacco

The faldh gene coding for a putative Brevibacillus brevis formaldehyde dehydrogenase (FALDH) was isolated and then transformed into tobacco. A total of three lines of transgenic plants were generated, with each showing 2- to 3-fold higher specific formaldehyde dehydrogenase activities than wild-type tobacco, a result that demonstrates the functional activity of the enzyme in formaldehyde (HCHO) oxidation. Overexpression of faldh in tobacco confers a high tolerance to exogenous HCHO and an increased ability to take up HCHO. A ¹³C-nuclear magnetic resonance technique revealed that the transgenic plants were able to oxidize more aqueous HCHO to formate than the wild-type (WT) plants. When treated with gaseous HCHO, the transgenic tobacco exhibited an enhanced ability to transform more HCHO into formate, citrate acid, and malate but less glycine than the WT plants. These results indicate that the increased capacity of the transgenic tobacco to take up, tolerate, and metabolize higher concentrations of HCHO was due to the overexpression of B. brevis FALDH, revealing the essential function of this enzyme in HCHO detoxification. Our results provide a potential genetic engineering strategy for improving the phytoremediation of HCHO pollution.     

石墨烯负载的金属氧化物纳米颗粒的可控制备及催化性能

采用直接浸渍法、过氧化氢均相氧化沉积法和氨水催化水解法制备了石墨烯负载的铁、钴、镍金属氧化物纳米颗粒.研究了三种沉积方法对颗粒尺寸分布的影响;采用透射电子显微镜、傅里叶变换红外光谱、X射线衍射和X射线光电子能谱表征了催化剂的形貌与结构.用过氧化氢均相氧化沉淀法可制得粒径分布最均匀的纳米颗粒.过氧化氢的氧化作用可使石墨烯表面的氧化基团含量最大化,为纳米颗粒提供了足够的吸附与成核点.氨水加速了金属离子的水解与成核,导致纳米颗粒的粒径增大与不均.以苯甲醇氧化为探针反应考察了催化剂的性能.催化剂的活性按以下顺序逐渐下降:过氧化氢辅助沉积法>直接浸渍法>氨水催化水解法,与纳米颗粒尺寸增长趋势一致.纳米催化剂颗粒尺寸与其活性的良好关联性显示,发展石墨烯负载尺寸可控的纳米催化剂的方法具有重要意义.     

Dual‐Mode Antibacterial Conjugated Polymer Nanoparticles for Photothermal and Photodynamic Therapy

In this work, dual‐mode antibacterial conjugated polymer nanoparticles (DMCPNs) combined with photothermal therapy (PTT) and photodynamic therapy (PDT) are designed and explored for efficient killing of ampicillin‐resistant Escherichia coli (Amp^r E. coli). The DMCPNs are self‐assembled into nanoparticles with a size of 50.4 ± 0.6 nm by co‐precipitation method using the photothermal agent poly(diketopyrrolopyrrole‐thienothiophene) (PDPPTT) and the photosensitizer poly[2‐methoxy‐5‐((2‐ethylhexyl)oxy)‐p‐phenylenevinylene] (MEH‐PPV) in the presence of poly(styrene‐co‐maleic anhydride) which makes nanoparticles disperse well in water via hydrophobic interactions. Thus, DMCPNs simultaneously possess photothermal effect and the ability of sensitizing oxygen in the surrounding to generate reactive oxygen species upon the illumination of light, which could easily damage resistant bacteria. Under combined irradiation of near‐infrared light (550 mW cm^?2, 5 min) and white light (65 mW cm^?2, 5 min), DMCPNs with a concentration of 9.6 × 10^?4 µm could reach a 93% inhibition rate against Amp^r E. coli, which is higher than the efficiency treated by PTT or PDT alone. The dual‐mode nanoparticles provide potential for treating pathogenic infections induced by resistant microorganisms in clinic.     

Robust Amino-Functionalized Mesoporous Silica Hollow Spheres Templated by CO2 Bubbles

Hollow-structured mesoporous silica has wide applications in catalysis and drug delivery due to its high surface area, large hollow space, and short diffusion mesochannels. However, the synthesis of hollow structures usually requires sacrificial templates, leading to increased production costs and environmental problems. Here, for the first time, amino-functionalized mesoporous silica hollow spheres were synthesized by using CO₂ gaseous bubbles as templates. The assembly of anionic surfactants, co-structure directing agents, and inorganic silica precursors around CO₂ bubbles formed the mesoporous silica shells. The hollow silica spheres, 200–400 nm in size with 20–30 nm spherical shell thickness, had abundant amine groups on the surface of the mesopores, indicating excellent applications for CO₂ capture, Knoevenagel condensation reaction, and the controlled release of Drugs.     

生物柴油及1,3-丙二醇联产工艺产业化进展

生物柴油作为可再生的清洁能源,已在美国、欧盟等多个国家和地区推行使用.在生物柴油的生产过程中,最高可得到约10%的副产物甘油,副产物甘油的去向将成为生物柴油大规模产业化发展所面临的严峻问题.1,3-丙二醇是一种重要的化工原料,作为合成新型聚酯PTT的原料,1,3-丙二醇已引起人们的广泛关注.以生物柴油副产物甘油为原料耦合生产1,3-丙二醇,不仅解决了生物柴油副产物甘油的出路问题,同时降低了1,3-丙二醇的生产成本.本文详细介绍了生物柴油及1,3-丙二醇生产技术及联产工艺的研究进展,并对其应用前景进行了展望.