光纤生物传感器用于核酸的特异性检测

为了利用光纤传感器实现对细菌核酸分子的特异性和相对快速检测，我们使用直径1mm的石英光纤和635nm激光二极管，利用倏逝波原理制作了光纤生物传感器。光纤经过处理后产生醛基化基团，然后与核酸分子进行共价结合。通过3个实验来验证传感器的特异性和灵敏度。蒌光素溶液直接检测，使用互补模式寡核苷酸分子（25mer)进行核酸杂交模式实验和设计嗜肺军团菌一段特异性探针一 光标记嗜肺军团菌染色体DNA杂交。结果表明：光纤检测荧光素的灵敏度可达0.01mmol/L，而生物芯片扫描仪最低可检测到1nmol/L的荧光素；模式寡 核苷酸杂交表明：光纤传感器可以特异地检出目的核酸分子，灵敏度可达纳克级水平；染色体杂交结果显示在正常检测浓度下，光纤检测军团菌之信噪比达到了6：1，同时具有较好的特异性。检测时间约需要3－4h。我们构建的光纤生物传感器可以用于核酸分子的特异性检测，并且具有较好的灵敏度，对光纤表面修饰、样品处理和杂交过程的优化可望使之应用于实际标本的检测。     

Nature of Bonding in Bowl‐Like B36 Cluster Revisited: Concentric (6π+18π) Double Aromaticity and Reason for the Preference of a Hexagonal Hole in a Central Location

The bowl‐shaped C_6v B₃₆ cluster with a central hexagon hole is considered an ideal molecular model for low‐dimensional boron‐based nanosystems. Owing to the electron deficiency of boron, chemical bonding in the B₃₆ cluster is intriguing, complicated, and has remained elusive despite a couple of papers in the literature. Herein, a bonding analysis is given through canonical molecular orbitals (CMOs) and adaptive natural density partitioning (AdNDP), further aided by natural bond orbital (NBO) analysis and orbital composition calculations. The concerted computational data establish the idea of concentric double π aromaticity for the B₃₆ cluster, with inner 6π and outer 18π electron counting, which both conform to the (4n+2) Hückel rule. The updated bonding picture differs from existing knowledge of the system. A refined bonding model is also proposed for coronene, of which the B₃₆ cluster is an inorganic analogue. It is further shown that concentric double π aromaticity in the B₃₆ cluster is retained and spatially fixed, irrespective of the migration of the hexagonal hole; the latter process changes the system energetically. The hexagonal hole is a destabilizing factor for σ/π CMOs. The central hexagon hole affects substantially fewer CMOs, thus making the bowl‐shaped C_6v B₃₆ cluster the global minimum.     

Synthesis of arylsulfonyl-substituted indolo[2,1-a]isoquinolin-6(5H)-one derivatives via a TBAI-catalyzed radical cascade cyclization

We have developed a metal-free radical cascade reaction of N-substituted 2-aryl indoles with readily available sulfonyl hydrazides for the rapid construction of arylsulfonyl-substituted indolo[2,1-a]isoquinolin-6(5H)-one derivatives. With the TBAI–TBHP catalytic system, a broad series of structurally diverse indolo[2,1-a]isoquinolin-6(5H)-one derivatives were obtained in moderate to excellent yields. The reaction features mild reaction conditions, operationally easiness, scaled-up feasibility, and high functional-group-tolerance.     

基于ZIF-8/PAN复合薄膜的柔性丙酮气体传感器

ZIF-8是一种Zn基金属有机骨架材料, 可以吸附丙酮气体从而作为电容式丙酮传感器的气敏材料, 然而ZIF-8的传统使用形式为粉末态, 这导致其不能成为具备柔性的整体, 从而限制了传感器的柔性. 结合包埋种子和二次生长法将ZIF-8与纳米纤维结合成纤维型柔性材料, 并将其作为气敏层制备了柔性电容式丙酮气体传感器. 该传感器在9种常见挥发性有机化合物中表现出良好的选择性, 对250~2000 cm³/m³的丙酮气体具有灵敏的响应、良好的循环响应及长期稳定性. 值得注意的是该柔性传感器不仅在室温下进行传感, 而且在弯折180°的状态下对丙酮气体的响应值与不弯折(0°)状态下几乎一致, 在200次以内的180°弯折-恢复后同样表现出了传感性能的稳定, 表明了其在柔性传感器方面的潜力.     

无衍射光的干涉实验与理论分析

分析了两束无衍射光的干涉场分布形式和干涉条纹轨迹。将一束单色光入射两小孔产生的两束相干光照射轴锥镜,在轴锥镜后将产生两束无衍射光。根据单束倾斜光入射轴锥镜的无衍射理论,分析出这两束无衍射光产生的干涉场为每束无衍射光的无衍射场的线性叠加。利用零阶贝塞尔函数的零点公式,推导出两束无衍射光的干涉条纹的轨迹为双曲线。计算结果表明,干涉场中两中心的间距与两孔实际的间距和干涉场距轴锥镜的距离成正比。实验结果与理论仿真相一致。     

毛细管电泳法快速测定复方地芬诺酯片中的地芬诺酯和阿托品

建立了毛细管电泳高频电导法同时测定地芬诺酯和阿托品的方法。探讨了缓冲溶液、有机溶剂添加剂、分离电压和进样条件以及毛细管内径和长度等因素对分离检测的影响。在电泳介质为10.0mmol/L乳酸-15.0?H5OH、分离电压20.0kV的优化条件下,6min内即可实现地芬诺酯和阿托品的同时分离检测,线性范围分别为5.00~500和2.00~320mg/L;检出限分别为3.0和1.0mg/L。     

Graphene-Oxide-Based Fluoro- and Chromo-Genic Materials and Their Applications

Composite materials and their applications constitute a hot field of research nowadays due to the fact that they comprise a combination of the unique properties of each component of which they consist. Very often, they exhibit better performance and properties compared to their combined building blocks. Graphene oxide (GO), as the most widely used derivative of graphene, has attracted widespread attention because of its excellent properties. Abundant oxygen-containing functional groups on GO can provide various reactive sites for chemical modification or functionalization of GO, which in turn can be used to develop novel GO-based composites. This review outlines the most recent advances in the field of novel dyes and pigments encompassing GO as a key ingredient or as an important cofactor. The interactions of graphene with other materials/compounds are highlighted. The special structure and unique properties of GO have a great effect on the performance of fabricated hybrid dyes and pigments by enhancing the color performance of dyes, the anticorrosion properties of pigments, the viscosity and rheology of inks, etc., which further expands the applications of dyes and pigments in dyeing, optical elements, solar-thermal energy storage, sensing, coatings, and microelectronics devices. Finally, challenges in the current development as well as the future prospects of GO-based dyes and pigments are also discussed. This review provides a reference for the further exploration of novel dyes and pigments.     

Preliminary study on aerosol particle addition calibration method for on-line quantitative analysis of airborne radioactive particles with ICP-MS

An ambient aerosol concentration enrichment system coupled with ICP-MS for real-time monitoring of airborne radioactive particles is now under development. ICP-MS is very sensitive to sample introduction conditions, so it is necessary to develop an easy-use calibration method for on-line quantitative analysis in field application. In this paper, a calibration method using standard solution instead of monodisperse particles was established and validated preliminarily. First of all, four parameters for the method were determined experimentally, including: uptake flow rate and nebulisation efficiency of the Microconcentric nebuliser, nebulisation/transport efficiency of Aridus Desolvating Sample Introduction System, and Relative Sensitivity Factor between ¹⁵⁹?Tb and ¹⁷⁴?Yb. Then, monodisperse terbium nitrate particles were generated by a commercial Vibrating Orifice Aerosol Generator. Continuous aerosols of ytterbium nitrate droplets were nebulised from standard solution. They were mixed together, desolvated through the membrane dryer and introduced into ICP-MS for on-line analysis of terbium nitrate particles. The air sampled from nuclear environment was also introduced into ICP-MS to investigate the effect of flow rate on instrument responses. Finally, atom numbers of ¹⁵⁹?Tb in discrete terbium nitrate particles were determined using the calibration method and compared to the calculated value. Results show that when air flow rate increase from 10?mL?min^?1 to 100?mL?min^?1, the ratio of ¹⁵⁹?Tb ion count to ¹⁷⁴?Yb ion intensity keeps constant although instrument sensitivity decreases by a factor of 25. The relative standard deviation of ¹⁵⁹?Tb atom number measured is better than 18%. The discrepancy with the calculated value could be attributed to the over-estimation of atom number in the particles generated by VOAG because there was some liquid leakage in the VOAG.     

One-pot synthesis of benzylacetamide from oxime under ultrasound irradiation

One-pot synthesis of benzylacetamide from oxime can be carried out in 80–95% yield at 35–40 °C under ultrasound irradiation. This method provided several advantages such as simple work-up procedure, shorter reaction time and higher yield.     

Structure and magnetic properties of Nb-doped FeZrB soft magnetic alloys

Structure and magnetic properties of Nb-doped (FeZrB)_100−xNb_x alloy are investigated by X-ray diffraction (XRD), differential scanning calorimetry and vibrating sample magnetometer. The fully amorphous structure of the as-quenched ribbons is confirmed by the XRD pattern. With increasing Nb, the glass transition temperature and the onset crystallization temperature are increased, indicating increased stability of the amorphous structure. For x=1, the saturation magnetization of the ribbons is 125.7 emu/g and the optimized annealing temperature increases from 550 to 630 °C. The morphology of the crystallized phases is observed by scanning electron microscopy. The results show that nanocrystalline α-Fe grains are dispersed in the amorphous matrix.