碳点在润滑领域中的应用

各种形式的摩擦和磨损不仅消耗了全球20%以上的能源,而且造成大量设备损坏。因此,开发减摩抗磨润滑材料对节约能源、延长机械设备使用寿命具有重要意义。碳点是一种新型的碳纳米材料,被广泛应用于化学传感、生物成像、催化、光电器件等领域。近年来,大量研究探索了碳点在工业润滑、微/纳米电子机械系统润滑、生物润滑等润滑领域的应用,证明了碳点具有优异的摩擦学性能,具备巨大潜力成为下一代绿色高效的减摩抗磨润滑材料。然而,至今仍缺乏碳点在润滑领域应用的系统性总结论述。因此,本文对碳点在润滑领域应用的研究进展作了全面系统综述。首先,详细介绍了碳点作为纳米添加剂和润滑涂层的润滑效果及提升其润滑性能的3种策略(尺寸形状控制、表面修饰、杂原子掺杂);然后,全面分析了碳点的润滑机理;最后概述了碳点在润滑领域应用所面临的主要挑战。     

Facile and robust strategy to antireflective photo-curing coating through self-wrinkling

We reported a facile and bio-inspired strategy for obtaining antireflective(AR) coating through polymerization-induced self-wrinkling. Upon irradiation of light, the complex wrinkle micro-patterns with different morphologies were generated spontaneously on the surface of coating during photo-crosslinking, which enables the photo-curing coating can decrease reflection. The resulting photo-curing coating exhibits a high transmittance over 90% and low reflection below 5%～8%, with an efficiency antireflection of 4%～7% compared to the flat blank coating. The successful application of these AR coatings with wrinkles pattern to encapsulate the thin film solar cells results in appreciable photovoltaic performance improvement of more than 4%～8%, which benefits from the decrease of the light reflection and increase of optical paths in the photoactive layer by the introduction of wrinkling pattern.Furthermore, the efficiency improvements of the solar cells are more obvious, with a remarkable increase of 8.5%, at oblique light incident angle than that with vertical light incident angle     

Identification of ilaprazole metabolites in human urine by HPLC‐ESI‐MS/MS and HPLC‐NMR experiments

Ilaprazole is a new proton pump inhibitor designed for the treatment of gastric ulcers, and limited data is available on the metabolism of the drug. In this article, the structural elucidation of urinary metabolites of ilaprazole in human was described by HPLC‐ESI‐MS/MS and stopped‐flow HPLC‐NMR experiments. Urinary samples were precipitated by sodium carbonate solution, and then extracted by liquid–liquid extraction after adding ammonium acetate buffer solution. The enriched sample was separated using a C₁₈ reversed‐phase column with the mobile phase composed of acetonitrile and 0.05 mol/L ammonium acetate buffer solution in a gradient solution, and then directly coupled to ESI‐MS/MS detection in an on‐line mode or ¹H‐NMR (500 MHz) spectroscopic detection in a stopped‐flow mode. As a result, four sulfide metabolites, ilaprazole sulfide (M1), 12‐hydroxy‐ilaprazole sulfide (M2), 11,12‐dihydroxy‐ilaprazole sulfide (M3) and ilaprazole sulfide A (M4), were identified by comparing their MS/MS and NMR data with those of the parent drug and available standard compounds. The main biotransformation reactions of ilaprazole were reduction and the aromatic hydroxylation of the parent drug and its relative metabolites. The result testified that HPLC‐ESI‐MS/MS and HPLC‐NMR could be widely applied in detection and identification of novel metabolites. Copyright © 2010 John Wiley & Sons, Ltd.     

Iron(II)‐Catalyzed Site‐Selective Functionalization of Unactivated C(sp3)−H Bonds Guided by Alkoxyl Radicals

An alkoxyl radical guided strategy for site‐selective functionalization of unactivated methylene and methine C?H bonds enabled by an Fe^II‐catalyzed redox process is described. The mild, expeditious, and modular protocol allows efficient remote aliphatic fluorination, chlorination, amination, and alkynylation of structurally and electronically varied primary, secondary, and tertiary hydroperoxides with excellent functional‐group tolerance. The application for one‐pot 1,4‐hydroxyl functionalization of non‐oxygenated alkane substrates initiated by aerobic C?H oxygenation is also demonstrated.     

Erratum: Fluorescent gel particles in the nanometer range for detection of metabolites in living cells

In the article above published in Volume 17 of Polymers for Advanced Technologies, pages 790–793 (2006) and online in Wiley InterScience , ( www.wileyinterscience.wiley.com ) DOI 10.1002/pat.786 the following changes should be recognised: On the second page of the paper, page 791, the sentence above figure 2 should have read ‘Since the headgroup areas of surfactants are a weak function of the condition under which they are used the function …’     

爆轰法制备球形纳米CeO2粉末

采用爆轰合成的方法,以Ce(NO3)3·6H2O为原料,制得了CeO2纳米粒子. 炸药采用黑索金粉,添加剂为CO(NH2)2,NaNO2. 爆轰产物经水洗,烘干后,利用X射线衍射仪器和高分辨率透射电镜对实验结果进行了分析. XRD结果表明,该法所得到的CeO2为立方晶系,颗粒平均粒度为33 nm. TEM图像显示其颗粒呈球形,颗粒大小主要分布在20～40 nm之间,颗粒具有较好的分散性. 球形纳米CeO2颗粒的形成原因有两点:(1) 由于爆轰过程的快速性和急剧冷却的特点,CeO2晶粒来不及择优生长; (2) 产物Na2CO3的熔点较低,爆轰时呈熔融状态包覆在CeO2晶核的周围,阻隔了CeO2晶粒的团聚生长.     

爆轰波碰撞的聚能效应

利用两高爆速导爆索对称布置于药卷两侧,起爆后炸药爆轰波在对称线处汇聚碰撞,当碰撞角度达到一定值时,发生马赫反射,使爆轰压力成倍增加,形成高压、高能量密度区域的聚能效应。本文在爆轰波传播碰撞理论的基础上,通过炸药做功能力和猛度试验验证爆轰波碰撞的聚能效果。做功能力试验结果表明爆轰波碰撞能够增加炸药能量利用率;猛度试验结果表明采用对称起爆技术下的爆轰波碰撞能够改变爆轰波在特定方向上的扩散作用。试验结果与爆轰波入射角的几何关系表明,当高爆速起爆药条与主装药爆速比例在1.15倍以上时,爆轰波碰撞能够达到一定的聚能效果。     

波纹板阻爆燃型阻火器对丙烷-空气预混火焰的淬熄研究

根据我国石油气体管道阻火器实验的国家标准(GB13347—92),对6组ⅡA类气体波纹板阻爆燃型阻火器进行了实验探究,得到了相应的阻火速度。实验结果表明:阻火器扩张比、阻火芯狭缝通道长度以及狭缝截面形状是影响阻火速度的主要因素。通过分析以上3个因素对阻火速度的影响,得出了阻火速度与阻火器基本参数的拟合公式。结果表明:阻火速度与狭缝通道的长度、扩张比的平方成正比,与狭缝截面三角形的特征尺寸成反比。