钙钛矿型甲醇水蒸气重整制氢催化材料的研究

采用溶胶凝胶法合成了钙钛矿复合氧化物,负载氧化铜后得钙钛矿负载型催化材料,通过XRD(X射线衍射分析)、BET(比表面积测试)、H2-TPR(程序升温还原分析)、XPS(X射线光电子能谱)等手段对催化材料进行了表征,考察了不同种类钙钛矿负载纳米铜催化材料的结构、性质对甲醇水蒸气重整制氢性能的影响.结果显示,钙钛矿负载纳...     

Ni(OH)2量子点助催化剂修饰α-Fe2O3光阳极增强光电分解水性能

氢气具有无毒、能量密度高以及燃烧过程零污染等优点,被誉为是未来代替化石能源的优质新型能源载体.探索高效的、可持续的制氢技术对氢气能源发展至关重要.其中,光电化学水分解电池以太阳能作为驱动力将水分解成氢气和氧气,是解决能源和环境危机的理想途径之一.α-Fe2O3是一种窄带隙(～2.1 eV)半导体,可以吸收约40％的太阳光,同时具有天然丰度高、成本低等优点,是目前备受关注的光阳极材料.然而,由于α-Fe2O3空穴扩散距离短和表面产氧动力学慢等缺点,导致α-Fe2O3的光电分解水效率仍然较低.针对上述问题,目前主要通过掺杂、构建异质结和负载助催化剂等手段来改善其性能.其中,负载助催化剂可以有效降低水氧化活化能和促进表面电荷分离,是改善光阳极性能的有效手段.本文采用离子吸附和螯合剂调控水解两步法,将Ni(OH)2量子点(Ni(OH)2 QDs)原位生长于α-Fe2O3表面,成功构建了Ni(OH)2 QDs/α-Fe2O3复合光阳极.透射电子显微镜结果表明,Ni(OH)2以直径为3–5 nm的量子点附着于α-Fe2O3纳米棒表面,并形成独特且牢固的异质结结构.光电水氧化性能表明,所制备的Ni(OH)2 QDs/α-Fe2O3光电阳极表现出良好的光电性能,其光电流达到了1.93 mA·cm?2(1.23 V vs.RHE),是单纯α-Fe2O3的3.5倍,且Ni(OH)2 QDs助催化剂使α-Fe2O3的起始电位降低了～100 mV.2 h稳定性测试结果表明,Ni(OH)2 QDs助催化剂在提升α-Fe2O3光电水氧化性能的同时,自身能够保持良好的稳定性,这在Ni(OH)2作为光电水氧化助催化剂的研究中较为少见.通过电化学活性面积、开路电压、电化学阻抗谱、注入效率和强度调制光电流谱等表征了Ni(OH)2 QDs对α-Fe2O3光阳极和电解液界面电荷传输的影响.结果表明,Ni(OH)2 QDs不仅能充分暴露水氧化活性位点,促进载流子在界面快速迁移,而且能有效钝化α-Fe2O3表面态,从而降低光生电子-空穴表面复合几率.本文可为多功能和高效量子点助催化剂/半导体光阳极的构建及在光电分解水制氢方面的应用提供一定借鉴.     

TiO_2助剂对乙苯脱氢催化剂性能的影响

研究了TiO_2助剂对乙苯脱氢催化剂的结构和其催化性能的影响以及对催化剂中铁钾尖晶石活性相形成的作用,并对催化剂的物理化学性质进行了表征.表征结果表明,引入适量的TiO_2能显著促进催化剂中活性相K_2Fe_(22)O_(34)的形成,减小CeO_2的晶粒尺寸,提高其在催化剂中的分散性;另一方面,添加助剂TiO_2后可以降低CeO_2和活性相K_2Fe_(22)O_(34)的还原温度,为反应提供更多的氧缺位和酸碱中心,提高了催化剂乙苯脱氢反应的活性.     

Simultaneous detection of five antibiotics in milk by high-throughput suspension array technology

A new suspension array technology is proposed for the simultaneous quantitative determination of five antibiotics—tylosin, tetracycline, gentamicin, streptomycin, and chloramphenicol in milk. A novel treatment of milk samples for suspension array with diethyl ether was performed which greatly reduced the interference of the disturbing components in milk on the reaction results with no significant effect on detection sensitivity. Compared with using biotin labeled monoclonal antibody, using of secondary antibody-biotin make the detection sensitivity further improved. The minimum detectable concentration in samples of tylosin, tetracycline, gentamicin, streptomycin, and chloramphenicol were 0.3, 1.5, 4, 20, and 25 ng/ml, respectively, and the working ranges of samples were 6-400, 7-300, 8-200, 90-3000 and 70-8000 ng/ml, respectively. The mean recovery was 89.38-113.73% with a standard deviation within 16.62%. The suspension assay technology is powerful for the fast quantitative analysis of multi-antibiotics residue in milk.     

A novel polymerization of ultrathin sensitive imprinted film on surface plasmon resonance sensor

A new surface-initiated polymerization based on pasting the initiator on a sensor chip surface was applied to prepare a malachite green (MG) imprinted ultrathin film on a surface plasmon resonance (SPR) sensor. First, the initiator (2,2-azoisobutyronitrile) was pasted on the gold surface using polyvinyl chloride (PVC). The initiator-covered gold chip was then soaked in a pre-polymerization solution prepared by dissolving methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross-linker), and MG (template) in DMSO in a weighing bottle. Finally, the weighing bottle was placed in a vacuum oven and thermal-initiated polymerization was conducted at 60 °C for 16 h. This method was simple and time-saving compared with the commonly used surface-initiated polymerization. More importantly, the molecularly imprinted polymer (MIP) film prepared using this method was much thicker than that of commonly used methods; the adsorption quantity was also much larger. The MIP modified SPR sensor showed high sensitivity and selectivity as well as good stability in detecting MG. The results suggest that the ultrathin MIP film prepared using the new method in this study is suitable to serve as the recognition element of the SPR sensor.     

Existence and asymptotics of traveling waves for nonlocal diffusion systems

In this paper, we deal with the existence and asymptotic behavior of traveling waves for nonlocal diffusion systems with delayed monostable reaction terms. We obtain the existence of traveling wave front by using upper-lower solutions method and Schauder’s fixed point theorem for c > c₁(τ) and using a limiting argument for c = c₁(τ). Moreover, we find a priori asymptotic behavior of traveling waves with the help of Ikehara’s Theorem by constructing a Laplace transform representation of a solution. Especially, the delay can slow the minimal wave speed for ?₂f(0, 0) > 0 and the delay is independent of the minimal wave speed for ?₂f(0, 0) = 0.     

分子印迹-仿生传感器的研究进展

分子印迹技术是制备具有选择性分子识别能力聚合物(分子印迹聚合物)的新兴化学合成技术。分子印迹聚合物的一个重要应用是在生物传感器中取代生物分子作为识别元件,研制耐受性强、低成本的分子印迹仿生传感器。综述了分子印迹技术的基本原理及其在仿生传感器方面的应用研究现状,并对分子印迹仿生传感器的发展前景进行了评述。引用文献24篇。     

An immunoassay for bisphenol A based on direct hapten conjugation to the polystyrene surface of microtiter plates

Based on direct hapten coated format a competitive indirect enzyme-linked immunosorbent assay (ciELISA) for bisphenol A (BPA) was developed. Polystyrene surface was modified by 3-Aminopropyltriethoxysilane (APTES) to produce amino groups after H₂SO₄/HNO₃-pre-treatment. 4,4-bis (4-hydroxyphenyl) valeric acid (BVA) which is analogue of BPA, was successfully immobilized on the surface of microtiter plates by N,N′-dicyclohexylcarbodiimide (DCC) method. The essential steps of the assay were optimized, especially blocking procedure which is key step to prevent unspecific binding of antibody. The results indicated that compared with hapten-protein coated format (IC₅₀ = 176.67 ng ml⁻¹, LOD = 15.90 ng ml⁻¹), the direct hapten coated format (IC₅₀ = 23.50 ng ml⁻¹, LOD = 0.27 ng ml⁻¹) could improve assay sensitivity and the detection ranges were 2.30 ng∼157.60 ng ml⁻¹ with good signal reproducibility (P value > 0.05) after careful optimization of assay conditions. Tap water samples and seawater samples were spiked with a known amount of BPA and measured by ciELISA. The average recoveries were between 70 and 142%. As far as we are aware this is the most sensitive ELISA for BPA yet reported.     

离子对反相高效液相色谱-蒸发光散射检测法测定三乙膦酸铝的含量

建立了以正丁胺为离子对试剂的反相高效液相色谱分析三乙膦酸铝含量的方法。采用Symmetry Shield RP18色谱柱分离,以甲醇-0.5%正丁胺水溶液(冰乙酸调节pH 5.0)(体积比为8:92)为流动相,流速为0.8 mL/min,蒸发光散射检测器(ELSD)检测。在上述条件下,三乙膦酸铝与其主要杂质亚磷酸盐、硫酸盐可以获得分离。在100～1200 mg/L范围内,进样质量与峰面积的双对数值呈良好的线性关系。100 mg/L和1000 mg/L两种质量浓度添加水平的回收率分别为100.58%和99.53%,其相对标准偏差(RSD)分别为0.62%和0.49%。该方法简便快捷,为三乙膦酸铝的定量分析提供了更加有效可靠的方法。