双丙酮丙烯酰胺的合成及提取工艺的优化

用正交实验设计法对双丙酮丙烯酰胺合成过程的工艺条件进行了优化 ,较优条件为 :n (丙酮 )∶ n (丙烯腈 )∶ n (浓硫酸 ) =2 .4∶ 1∶ 1 .1 ,反应温度 50℃ ,反应时间 4 h。对产品的提取工艺进行了改进 :将反应液在减压蒸馏前用水萃取 ,盐析 ,碱洗 ,除去大部分杂质。碱洗所用的 1 5%氢氧化钠溶液∶有机层 (质量比 ) =2∶ 1 0。产物经减压蒸馏后无需重结晶 ,收率 54.5% ,熔点 53～ 56℃。     

Ultrathin polyaniline film coated on an indium–tin oxide cell-based chip for study of anticancer effect

Polyaniline emeraldine base (EB) coated indium–tin oxide (ITO) electrode was prepared for the construction of a cell-based chip. Ultrathin polyaniline PANI film on an ITO was electroactive at neutral pH without co-deposition of an acidic counterion. HeLa cells were cultured on a PANI/ITO substrate and utilized to assess the biological toxicity of anticancer drugs. Cell growth, cell viability and drug-related cell toxicity were evaluated by a cyclic voltammetry (CV) method under a neutral pH. We demonstrated the functionality of a PANI coated ITO electrode for use as a cell chip and found that PANI was a good surface for the HeLa cells to grow without any significant morphological changes.     

Exogenous γ‐aminobutyric acid alleviates oxidative damage caused by aluminium and proton stresses on barley seedlings

BACKGROUND: Proton (H⁺) and aluminium (Al³⁺) toxicities are major factors limiting crop production on acid soils, while γ‐aminobutyric acid (GABA) is a non‐protein amino acid involved in various stress tolerances in plants. In this study, to determine whether exogenous GABA is functional in alleviating oxidative stress induced by H⁺ and Al³⁺ toxicities, the antioxidant defence response regulated by GABA was investigated in barley (Hordeum vulgare L.). RESULTS: After 24 h treatments of seedlings under H⁺, Al³⁺ and combined stresses with and without GABA, morphological and biochemical assays were conducted. It was observed that the inhibition of seedling root elongation caused by Al³⁺ and H⁺ toxicities was significantly mitigated by GABA. The amount of carbonylated proteins with molecular masses of 14.4–97 kDa was decreased. The activities of antioxidant enzymes were enhanced, the content of malondialdehyde was reduced and the accumulation of reactive oxygen species (ROS), as shown by staining roots with nitroblue tetrazolium, declined in GABA‐treated seedlings. CONCLUSION: GABA can alleviate oxidative damage caused by H⁺ and Al³⁺ toxicities in barley seedlings by activating antioxidant defence responses and reducing the elevated levels of carbonylated proteins caused by ROS. Copyright © 2010 Society of Chemical Industry     

钻头优选的TOPSIS法

在评述目前选择钻头方法的基础上，提出了TOPSIS法评选钻头。该方法具有限制条件少，应用灵活方便等特点。并详细地介绍了该方法的原理和计算步骤，同时运用油田的实钻资料进行了计算。结果表明，该方法计算简便，结果与现场实际相符，便于现场应用。     

地层压力研究方法的新进展

地层压力值是石油勘探与开发各项工作必须掌握的基础数据之一.文中介绍了国际检测地层压力方法中存在的问题,并概述了地层压力研究方法的最新进展及其发展方向.     

高温高压井套管柱设计和强度校核

从温度对套管柱强度的影响、下部套管柱双轴应力计算等几个方面讨论了高温高压对套管柱设计和强度校核的影响 ,提出了一套适用于高温高压井套管柱设计和强度校核的理论方法 ,并给出了该方法的计算步骤 ,编制了相应的计算软件。通过现场应用 ,证明该方法切实可行     

自动抄表系统

自动抄表技术是新兴的、先进的抄表方式,融合了当今最先进的计算机和通信技术,并随着通信技术系统的硬件和软件不断发展而更新,本介绍了自动抄表系统的基本组成、载波抄表和GMS远程抄表系统的应用。     

丹江口大坝加高新老混凝土结合面灌浆效果分析

混凝土新老坝体的结合问题是南水北调丹江口大坝加高工程的主要技术难题之一。施工初期的结合面基本上结合完好,但在外界气温年际变化的影响下,后期都有不同程度的张开,因此,通常采取灌浆措施。但是,灌浆以后,在环境温度年际变化的作用下,结合面是否会再次张开,灌浆是否起到作用,这些都是设计、施工人员非常关心的问题。结合丹江口大坝2号坝段加高的施工过程,通过三维非线性有限元模拟计算分析,研究新老混凝土结合面张开后的灌浆效果。研究认为:对新老混凝土结合面进行灌浆处理,能够有效提高结合面的接触面积,对降低整个上游面竖向拉应力是有利的。     

陶岔渠首引水闸温度应力分析及施工安排探讨

通过模拟陶岔渠首枢纽工程引水闸结构的施工建造过程,分析引水闸孔顶水平向拉应力较大的原因。认为引水闸结构孔顶出现较大的拉应力是施工期温度应力过大所致,产生原因是施工间歇期过长,解决办法是尽可能安排孔顶上方混凝土按正常间歇期(7~14 d)浇筑,避免出现长间歇期。提出:如果孔顶至158 m高程混凝土不能确保在2012年3月前完成浇筑,就应推迟到2012年5~6月浇筑。通过这样处理,可以解决孔顶施工期温度应力过大的问题。