Amphibious sensor of temperature and refractive index based on D-shaped photonic crystal fibre filled with liquid crystal

ABSTRACT

A D-shaped photonic crystal fibre filled with liquid crystal was demonstrated as an amphibious sensor for detection of both temperature and refractive index, when combined with plasma materials. Specifically, the optical component is implanted into a complete optical system ensuring modulation of the external electric field. When the refractive index of the external solution changes from 1.0 to 1.6, the y-polarised mode has a loss spectrum with a wavelength sensitivity of up to 2275 nm/RIU, and the corresponding amplitude sensitivity is ?88.2RIU^?1. When the perceived temperature changes from 15°C to 50°C, the temperature of the sensor is correspondingly expressed as the maximum wavelength sensitivity of 9.09 nm/°C and the amplitude sensitivity of ?0.311°C^?1. In addition, the actual micro-operation processes have been studied in detail, such as polishing depth, coating thickness and coating method. This provides practical ideas for real-time sensing analysis that requires harsh environments.     

新型多孔芳香骨架材料用于硝基爆炸物的检测

采用付玫瑰苯胺与对苯二甲醛通过希夫碱偶联反应制备了新型的多孔芳香骨架材料.经过FTIR,TGA,PXRD,SEM,TEM和Ar吸附等分析方法对多孔芳香骨架材料的成键方式和骨架结构进行了表征.分析结果显示,该多孔芳香骨架材料具有优异的热稳定性(350℃仅失重5%)和溶剂稳定性,其Langmuir比表面积约为472m~2/g.紫外光谱和荧光光谱测试分析表明,该材料在苯、甲苯和氯苯等芳香化合物环境中无明显的荧光强度变化.然而在硝基爆炸物环境中会发生灵敏的、专一的荧光淬灭现象.该多孔材料可应用于硝基爆炸物的检测.     

Effect of selected dopants on conductivity and moisture stability of Li3PS4 sulfide solid electrolyte: a first-principles study

The first principle computational screening was performed to investigate the effect of selected dopants for Li₃PS₄ sulfide solid electrolyte on its ionic conductivity and stability toward moisture. The results suggest that substitution P⁵⁺ using isovalent cations whose electronegativity (EN) value is closer to the value of S has more significant effects on the ionic conductivity, whereby W⁵⁺ and Sb⁵⁺ can improve most. Similarly, aliovalent cation substitutions with compensating changes in the lithium-ion concentration, particularly those with a lower oxidation state and higher EN, such as Cu²⁺, effectively enhance the lithium-ion conductivity in this structure. For cation dopants, it is found that ionic conductivity improvement of Li₃PS₄ is the synergetic effect of EN and oxidation number of the dopant as well as the material's lattice parameter change. Oxides of the considered cation dopants can also improve the ionic conductivity of the material but have much lower lithium-ion conductivity than the cases of cation dopants. However, the metal oxide dopants, particularly those derived from soft Lewis' acid cations, show a marginal improvement in moisture stability of the Li₃PS₄ electrolyte. The effect of halides and metal halide dopants on the lithium-ion conductivity and moisture stability of Li₃PS₄ electrolyte are also studied. It is found that metal halides are more effective than any other dopants in improving the ionic conductivity of Li₃PS₄.     

An expedient synthesis of ellipticine via Suzuki-Miyaura coupling

A simple and efficient total synthesis of ellipticine was developed via the Suzuki-Miyaura coupling of sterically sensitive 2-hydroxybenzeneboronic acid with a multifunctional aryl halide using Pd(OAc)₂ as a catalyst and Cu(OAc)₂·H₂O as an additive in DMSO/H₂O as a key step followed by double N-arylation and cyclization.     

Solar‐Energy‐Driven Photoelectrochemical Biosensing Using TiO2 Nanowires

Photoelectrochemical sensing represents a unique means for chemical and biological detection, with foci of optimizing semiconductor composition and electronic structures, surface functionalization layers, and chemical detection methods. Here, we have briefly discussed our recent developments of TiO₂ nanowire‐based photoelectrochemical sensing, with particular emphasis on three main detection mechanisms and corresponding examples. We have also demonstrated the use of the photoelectrochemical sensing of real‐time molecular reaction kinetic measurements, as well as direct interfacing of living cells and probing of cellular functions.     

老年人彩度对比敏感度函数研究及滤波应用

为研究老年人彩色视觉频率响应特性，获取彩度对比敏感度与空间频率之间的函数关系，本文在LCH均匀颜色空间基础上，固定明度和色调角值，以彩度作为变量，设计人眼彩度对比敏感度实验，进行人眼视觉观察实验。获得彩度对比敏感度与空间频率的关系，并构建指数型对比敏感度函数模型。经分析表明老年人眼彩度对比敏感度随着空间频率的增加，产生先升高再缓慢降低的变化，各色调角下彩度对比度存在差异。经分析人眼对比敏感度差异与人眼视觉辨色特性有很大的相关性。并且，将构建的对比敏感度函数模型用于实现基于人眼视觉系统的滤波处理。     

A novel route to prepare pH- and temperature-sensitive nanogels via a semibatch process

A novel method via a semibatch process in the absence of surfactant has been adopted to prepare pH- and temperature-sensitive nanogels. The shape, charge distribution, temperature, and pH-induced volume phase transition behavior of the latexes were investigated by scanning electronic microscopy, zeta potentials, dynamic laser light scattering, and UV/vis spectroscopy. It was found that, in the absence of surfactant, with increasing the amount of AAc from 5 to 20 mol% of N-isopropylacrylamide (NIPAM), the hydrodynamic diameters (D_H) decrease from 230 to 60 nm. With increasing pH value from 3 to 11, the D_H values increase slightly, which is different than the dramatic increase seen when using a conventional batch method with a range from 680 to 1700 nm. However, at pH 3, the turbidity curves of these kinds of particles increase dramatically at temperatures between 33 and 37 °C, while remaining constant at first and then increasing directly at pH 11. Furthermore, the distribution of carboxylic groups located not only on the interior but also on the exterior of colloidal particles as a result of adoption of the semibatch method, other than simple surface distribution of poly(NIPAM-co-AAc) latexes via the batch method.     

直流辉光放电质谱法测定多晶硅中关键杂质元素的相对灵敏度因子

采用直流辉光放电质谱(dc-GD-MS)测定多晶硅中关键杂质元素的相对灵敏度因子(RSF).标样制作过程中主要是在连续通入氩气条件下将固定量的非标准多晶硅样品熔化,向硅熔体中均匀掺入浓度范围为1～30 μg/g的关键杂质元素(如B和P),采用快速固化法制成标样;再将制成的标准样品加工成一系列适合GD-MS扁平池(Flat Cell)的片状样品(20 mm×20 mm×2mm).采用二次离子质谱法(SI-MS)对标准样品中关键掺杂元素进行多次定量测定,取平均值作为关键杂质元素的精确含量.优化一系列质谱条件后,运用GD-MS对标样中关键掺杂元素的离子强度进行多次测定,计算平均结果,得到未校正的表观浓度,利用标准曲线法计算出关键杂质元素的相对灵敏度因子.     

Direct analysis of anabolic steroids in urine using Leidenfrost phenomenon assisted thermal desorption-dielectric barrier discharge ionization mass spectrometry

Rapid detection of trace level anabolic steroids in urine is highly desirable to monitor the consumption of performance enhancing anabolic steroids by athletes. The present article describes a novel strategy for identifying the trace anabolic steroids in urine using Leidenfrost phenomenon assisted thermal desorption (LPTD) coupled to dielectric barrier discharge (DBD) ionization mass spectrometry. Using this method the steroid molecules are enriched within a liquid droplet during the thermal desorption process and desorbed all-together at the last moment of droplet evaporation in a short time domain. The desorbed molecules were ionized using a dielectric barrier discharge ion-source in front of the mass spectrometer inlet at open atmosphere. This process facilitates the sensitivity enhancement with several orders of magnitude compared to the thermal desorption at a lower temperature. The limits of detection (LODs) of various steroid molecules were found to be in the range of 0.05–0.1 ng mL⁻¹ for standard solutions and around two orders of magnitude higher for synthetic urine samples. The detection limits of urinary anabolic steroids could be lowered by using a simple and rapid dichloromethane extraction technique. The analytical figures of merit of this technique were evaluated at open atmosphere using suitable internal standards. The technique is simple and rapid for high sensitivity and high throughput screening of anabolic steroids in urine.     

单金纳米棒的光散射分析化学:径向比与分析灵敏度的关系

单纳米颗粒作为信号感应单元在化学与生物传感应用中已引起广泛关注.本文通过暗场显微成像(iDFM)研究了不同径向比金纳米棒的光散射性质.将iDFM与扫描电子显微镜(SEM)结合表征种子生长法制备的金纳米棒,结果发现,因局域表面等离子体共振而展示出的红色散射光随单个金纳米棒的径向比增大逐渐红移,且金纳米棒对其周围介质折光率(RI)变化的敏感程度随径向比增大而增大.这一结果对设计高灵敏的生物纳米传感器、提高分析检测的灵敏度具有很好的指导意义.