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991.
金属辅助化学腐蚀法可以在无外加电路的条件下,在40%HF/30%H2O2/乙醇的混合溶液中完成多孔硅的制备,该方法简单快速。本文研究了金属辅助法腐蚀液体系各组分(HF、H2O2、乙醇)含量对多孔硅表面的SiHx成分和多孔层结构的影响,根据Si-H和Si-O的红外吸收峰强度的变化曲线优化了腐蚀液体系中各组分含量。在腐蚀液各组分体积比为V40%HF∶V30%H2O2∶V乙醇=2∶2∶1和腐蚀时间为4 min的条件下制备了形貌均匀、化学活性(SiHx成分)和多孔结构稳定性较好的多孔硅,并对金属辅助法与阳极蚀刻法制得的两种多孔硅进行比较,结果显示金属辅助法制备的多孔硅的化学活性和稳定性在后续的生物技术应用中具有明显的优越性。 相似文献
992.
An efficient synthetic method for bis(indol-3-yl)alkane derivatives has been developed.In the presence of 5 mol%of pyridinium tribromide(PTB),the condensation of indoles and aldehydes proceeded smoothly under mild conditions,giving rise to the corresponding bis(indol-3-yl)alkanes in good to excellent yields. 相似文献
993.
Three novel conjugated polymers bearing 3,4-bis(4-hexylthiophen-2-yl)-3-cyclobutene-1,2-dione unit in their main chain have been synthesized successfully in good yields through Suzuki or Stille coupling reaction.Their molecular structures have been confirmed by FT-IR,1H NMR and 13C NMR.All these copolymers exhibit broad and strong absorption bands in UV-vis region,and their optical band gaps are calculated to be 1.6-2.0 eV.suggesting that they have good coverage with the solar spectrum.These polymers have good thermostability and solubility in common organic solvents.Moreover,all these objective macromolecules possess high electron affinity of~3.8 eV determined from cyclic voltammetry measurement,implying that they are potential n-type polymeric photovoltaic materials. 相似文献
994.
A new pyridoxal‐5‐phosphate (PLP) derivative FHMDP was developed for the transamination of different peptides with three most hindered amino acid residues (Leu, Ile, Val) as their N‐terminus. Compared to the previously reported reactions of PLP derivatives, the N‐terminus transamination could be accomplished efficiently with the new compound. 相似文献
995.
Synthesis, Crystal Structure, and Herbicidal Activities of 2-Cyanoacrylates Containing 1,3,4-Thiadiazole Moieties 总被引:1,自引:0,他引:1
Tingting Wang Wenke Miao Shanshan Wu Guifang Bing Xin Zhang Zhenfang Qin Haibo Yu Xue Qin Jianxin Fang 《中国化学》2011,29(5):959-967
Three series of novel 2‐cyanoacrylates 7a – 7f , 9a – 9f , 10a – 10f containing 1,3,4‐thiadiazole ring moieties were synthesized as herbicidal inhibitors of photosystem II (PS II) electron transportation. Their structures were clearly verified by 1H NMR, 13C NMR, elemental analysis (or HRMS analysis) and single‐crystal X‐ray diffraction analysis. Bioassay showed that a suitable group at the 3‐position of acrylates was essential for high herbicidal activity. In particular, compound 7e showed the best herbicidal activities and gave 100% inhibitory activity against rape and amaranth pigweed at a dose of 1.5 kg/ha. Introduction of substituent with higher polarity such as sulfinyl or sulfonyl to the 5‐position of 1,3,4‐thiadiazole decreased herbicidal activities. 相似文献
996.
Er Fu Huoa Yong Zoua Hui Qin Sunb Yan Huang Zhi Yun Lua Qing Jianga a College of Chemistry.Sichuan University Chengdu China b Analytical & Testing Center Sichuan University China 《中国化学快报》2011,(11)
Three novel conjugated polymers bearing 3,4-bis(4-hexylthiophen-2-yl)-3-cyclobutene-1,2-dione unit in their main chain have been synthesized successfully in good yields through Suzuki or Stille coupling reaction.Their molecular structures have been confirmed by FT-IR,~1H NMR and ~(13)C NMR.All these copolymers exhibit broad and strong absorption bands in UV-vis region,and their optical band gaps are calculated to be 1.6-2.0 eV.suggesting that they have good coverage with the solar spectrum.These polymers... 相似文献
997.
998.
Sang M Xie J Qin XC Wang WD Chen XB Wang KB Zhang JP Li LB Kuang TY 《Journal of photochemistry and photobiology. B, Biology》2011,102(3):177-181
The generation of superoxide radical (O?·?) in Cyt b?f of Bryopsis corticulans under high light illumination was studied using electron paramagnetic resonance (EPR) spectroscopy. This could be evidenced by the addition of SOD which specifically reacted with O?·?. The generation of O?·? was lost in the absence of oxygen and was found to be suppressed in the presence of NaN? and be scavenged by extraneous antioxidants such as ascorbate, β-carotene and glutathione which could also scavenged 1O?*. These results indicated that O?·? which produced under high light illumination in Cyt b?f of B. corticulans might rise from a reaction which 1O?* could participated in. Also the photo-protection mechanism to Cyt b?f complex by antioxidants which might contain in thylakoid was speculated. 相似文献
999.
Zheng‐Hui Fang Li‐Min Lu Xiao‐Bing Zhang Hong‐Bo Li Bin Yang Guo‐Li Shen Ru‐Qin Yu 《Electroanalysis》2011,23(10):2415-2420
A new third‐generation biosensor for H2O2 assay was developed on the basis of the immobilization of horseradish peroxidase (HRP) in a nanocomposite film of carbon nanotubes (CNTs)‐SBA‐15 modified gold electrode. The biological activity of HRP immobilizing in the composite film was characterized by UV‐vis spectra. The HRP immobilized in the nanocomposite matrix displayed excellent electrocatalytic activity to the reduction of H2O2. The effects of the experimental variables such as solution pH and working potential were investigated using steady‐state amperometry. Under the optimal conditions, the resulting biosensor showed a linear range from 1 µM to 7 mM and a detection limit of 0.5 µM (S/N=3). Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results. 相似文献
1000.
A novel poly(aniline‐co‐o‐aminophenol) (PAOA)/mesoporous silica SBA‐15 nanocomposite was synthesized and investigated for adsorption of Hg (II) from aqueous solutions of wide pH range. A chemical oxidation method was employed for polymerization of aniline and o‐aminophenol on an ordered SBA‐15 template to obtain a significantly enlarged BET surface area of the adsorbent. Efficiency study revealed that the PAOA/SBA‐15 could reach a maximum Hg (II) adsorption capacity of over 400 mg/g. Kinetic study showed that the Hg (II) adsorption by the PAOA/SBA‐15 fitted a pseudo‐second‐order kinetic model, indicating that the mercury adsorption process was predominantly controlled by chemical process. The results of this study also proved that the adsorbed Hg (II) could be effectively desorbed from the PAOA/SBA‐15 in 0.1M HCl and 5% sulfocarbonide solutions. Associated adsorption mechanism was also investigated by means of Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS) techniques. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献