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The plasma window is an advanced apparatus that can work as the interface between a vacuum and a high pressure region. It can be used in many applications that need atmosphere-vacuum interface, such as a gas target, electron beam welding, synchrotron radiation and a spallation neutron source. A test bench of the plasma window is constructed in Peking University. A series of experiments and the corresponding parameter measurements have been presented in this article. The experiment result indicates the feasibility of such a facility acting as an interface between a vacuum and a high pressure region. 相似文献
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Influence of Sulfation on the Catalytic Activity of Ni-ZrO2 for NO Reduction with Propane in Excess Oxygen 下载免费PDF全文
Selective catalytic reduction (SCR) of nitric oxide with propane in excess oxygen was investigated on Ni-ZrO2 (NZ) and sulfated Ni-ZrO2 (SNZ), prepared by coprecipitation from a mixture of nickel nitrate-zirconium oxychloride followed by modifying with (NH4)2SO4. It was found that sulfated Ni-ZrO2 catalyst showed higher activity for the SCR of NO with propane than that of Ni-ZrO2. The structural and surface properties of catalysts were studied by XRD, BET, SEM and FT-IR of pyridine adsorption. The experimental results indicated that the modification of (NH4)2SO4 resulted in the generation of strong BrOnsted and Lewis acid sites and promoted the dispersion of the Ni species, which could lead to higher NO conversion and propane efficiency in NO reduction. 相似文献
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将滚环扩增技术与铜纳米线相结合进行信号放大,建立高选择性、高灵敏的汞离子比色检测新方法。以链霉亲和素修饰的磁珠为探针捕获和分离基质,将生物素修饰的引物链固定到其表面。汞离子存在时,模板链将通过T-Hg^2+-T作用与引物链结合。加入T4连接酶及DNA聚合酶引发滚环扩增反应形成超长单链DNA。与短单链DNA互补形成的长双链DNA可作为铜纳米线沉积模板,加入盐酸释放出大量铜离子催化底物氧化显色。在0.005~1.0 nmol/L范围,汞离子浓度与吸收信号呈良好线性关系,检出限低至3.7 pmol/L。 相似文献
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聚乳酸(PLA)纳米纤维在环境友好型纤维过滤材料领域有良好的应用前景,但受制于其本征螺旋分子链构象和低介电常数的不足,导致其驻极性能差、过滤性能(过滤效率及压降)易衰减以及有效服役周期短.本文将高旋光性的聚L-乳酸(PLLA)和聚D-乳酸(PDLA)溶液共混,并通过静电纺丝过程的高压静电场诱导C=O基团加速取向极化,形成高电活性的立构复合晶体(SCs),显著提高聚乳酸纳纤膜的表面电位、介电常数及驻极效果等电活性特征,增大纤维表面静电斥力,促进PLA纳纤膜(PLA NFMs)的纤维细化,从而使其压降大幅降低(85 L/min, 209.2 Pa),过滤PM2.5效率显著提高至96.32%(纯PLLA对比样为72.44%).更重要的是,立构复合化PLA纳纤膜(SC-PLA NFMs)的过滤性能受气体流量变化影响较小(10~85 L/min),当气流增大时,过滤效率的衰减远远低于纯PLLA,在高气流下的稳定性使其能更好地满足在空气过滤领域的实际应用需求.此外,提高PLA纳纤膜电活性可显著增强摩擦生电输出性能和呼吸振动激发电信号,为基于人体呼吸的生理特征监测奠定理论基础.... 相似文献
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We propose a new non-intrusive flow measurement method using the distributed feedback fiber laser(DFB-FL)as a sensor to monitor flow in the pipe.The relationship between the wavelength of the DFB-FL and the liquid flow rate in the pipeline is derived.Under the guidance of this theory,the design and test of the flow sensor is completed.The response curve is relatively flat in the frequency range of 10 Hz to 500 Hz,and the response of the flow sensor has high linearity.The flow from 0.6 m^3/h to 25.5 m^3/h is accurately measured under the energy analysis method in different frequency intervals.A minimum flow rate of 0.046 m/s is achieved.The experimental results demonstrate the feasibility of the new non-intrusive flow measurement method based on the DFB-FL and accurate measurement of small flow rates. 相似文献
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在水热条件下以吡啶-2,6-二羧酸和哌嗪作为配体合成了一种新的镨(Ⅲ)配合物:(H_2pipz)_(1.5)[Pr(pdc)_3]·7H_2O(1,pdc~(2-)=吡啶-2,6-二羧酸根;pipz=哌嗪),并借助红外光谱、元素分析和X射线单晶衍射对其进行了结构表征,进而采用密度泛函理论(DFT)方法探究了配合物1的基本结构单元的电子结构。此外,抗肿瘤实验表明配合物1对K562(IC_(50)=(61.3±10.20)μg·mL~(-1))和OE-19细胞(IC_(50(=(15.9±3.24)μg·mL~(-1))均表现出较强的细胞毒性,尤其是对OE-19细胞具有更强的抑制效果。 相似文献