脉冲核磁共振测定化学位移的实验

针对高校物理实验中近代物理开设不足之处,提出了开设脉冲核磁共振测定化学位移的实验,根据设定的实验方案,测量并计算出二甲苯的化学位移,实现了由理论向应用转化的初步探索。     

地下工程软弱岩体围岩结构的地震探测技术

控制地下工程软弱岩体特征的一个重要前提是围岩工程地质条件评价以及围岩的地质结构的定量认识,而目前软岩巷道支护难的主要原因是对巷道工程地质条件和围岩结构认识不清、支护对象不明确。基于以上分析,本文以显德汪矿主运输巷道为试验研究对象,采用地震技术对软弱岩体围岩结构进行了全断面探测,实现了岩体结构的空间定位和精确探测,进而为支护形式和支护参数的选择提供了直观可靠的工程地质依据。     

Cytotoxicity Induction by the Oxidative Reactivity of Nanoparticles Revealed by a Combinatorial GNP Library with Diverse Redox Properties

It is crucial to establish relationship between nanoparticle structures (or properties) and nanotoxicity. Previous investigations have shown that a nanoparticle’s size, shape, surface and core materials all impact its toxicity. However, the relationship between the redox property of nanoparticles and their toxicity has not been established when all other nanoparticle properties are identical. Here, by synthesizing an 80-membered combinatorial gold nanoparticle (GNP) library with diverse redox properties, we systematically explored this causal relationship. The compelling results revealed that the oxidative reactivity of GNPs, rather than their other physicochemical properties, directly caused cytotoxicity via induction of cellular oxidative stress. Our results show that the redox diversity of nanoparticles is regulated by GNPs modified with redox reactive ligands.     

Ultrasensitive and accelerated detection of ciguatoxin by capillary electrophoresis via on-line sandwich immunoassay with rotating magnetic field and nanoparticles signal enhancement

A sensitive and rapid on-line immunoassay for the determination of ciguatoxin CTX3C was developed based on a capillary mixing system, which was integrated with capillary electrophoresis (CE) separation and electrochemical (EC) detection. In the sandwich immunoassay system, anti-CTX3C-functionalized magnetic nanoparticles were used as immunosensing probes, and horseradish peroxidase (HRP) and anti-CTX3C antibody were bound onto the surface of gold nanoparticles (AuNPs) and used as recognition elements. Online formation of immunocomplex was realized in capillary inlet end with an external rotating magnetic field. Compared with classical HPLC-MS and ELISA, the assay adopting AuNPs as multienzyme carriers and online sandwich immunoassay format with rotating magnetic field exhibited higher sensitivity and shorter assay time. The linear range of the assay for CTX3C was from 0.6 to 150 ng/L with a correlation coefficient of 0.9948 (n = 2), and the detection limit (S/N = 3) was 0.09 ng/L. The developed assay showed satisfying reproducibility and stability, and it was successfully applied for the quantification of CTX3C in fish samples.     

A glassy carbon electrode modified with poly(3,4-ethylenedioxythiophene) doped with nano-sized hydroxyapatite for amperometric determination of nitrite

A conducting polymer composite was prepared from nano-sized hydroxyaptite (nHAp) doped into poly(3,4-ethylenedioxythiophene) (PEDOT) and then electrodeposited on a glassy carbon electrode (GCE). The nHAp carries carboxy groups and therefore is negatively charged at moderate pH value. When doped into PEDOT (PEDOT-nHAp), it forms a uniform and stable film that exhibits low electrochemical impedance, a large specific surface, and high activity toward the electrochemical oxidation of nitrite. Under optimized conditions and at a relatively low working potential of 0.78 V (vs. SCE), the modified GCE exhibited a linear amperometric response in the 0.25 μM to 1.05 mM nitrite concentration range, and the limit of detection is as low as 83 nM.

Open image in new window

Graphical abstract A highly sensitive nitrite sensor was developed based on conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with carboxyl group functionalized hydroxyapatite nanoparticles, which exhibited a large surface area and good conductivity and stability.

     

Enzymeless voltammetric hydrogen peroxide sensor based on the use of PEDOT doped with Prussian Blue nanoparticles

An electrochemical sensor for H₂O₂ was developed based on electrochemically deposited Prussian blue (PB) nanoparticles doped poly(3,4-ethylenedioxythiophene) (PEDOT). The PEDOT/PB composite was composed of PEDOT wrapped PB nanoparticles, where the conducting polymer PEDOT not only protected the PB particles to warrant high stability, but also connected them to enhance the electron transfer. Owing to the excellent conductivity of PEDOT and unique electrocatalytic activity of PB, the PEDOT/PB modified electrode exhibited good catalytic activity toward the electrochemical reduction of H₂O₂, and was used for the detection of H₂O₂ in concentrations ranging from 0.5 to 839 μM, with a detection limit of 0.16 μM. Moreover, the sensor also demonstrated excellent reproducibility, selectivity and long-term stability, showing great promise for the fabrication of electrochemical sensors and H₂O₂ related biosensors.

Open image in new window

Graphical abstract An electrochemical non-enzymatic sensor for hydrogen peroxide with excellent stability was developed. It is based on conducting polymer PEDOT doped with Prussian blue nanoparticles.

     

Nanocomposite and nanoporous polyaniline conducting polymers exhibit enhanced catalysis of nitrite reduction

Nanostructured polyaniline (PANI) conducting polymer films were prepared on electrochemically pretreated glassy carbon electrodes, which were previously modified with multilayers of polystyrene (PS) nanoparticles with a diameter of 100 nm. PANI was electropolymerised and grown through the interstitial spaces between the PS nanoparticles, which formed a nanocomposite film of PANI and PS nanoparticles on the electrode surface. Furthermore, a nanoporous PANI film was fabricated through the removal of the PS nanoparticles by dissolution in toluene. As a result of their nanostructure, both of the PANI films (before and after removal of the PS nanoparticles) exhibited enhanced electrocatalytic behaviour towards the reduction of nitrite relative to bulk-PANI films; however, partial collapse or shrinkage may have occurred with the removal of the nanoparticles and could have resulted in a less enhanced response. Under optimised conditions, the nanocomposite-film-modified electrode exhibited a fast response time of 5 s and a linear range from 5.0 x 10(-7) to 1.4 x 10(-3) M for the detection of nitrite; the detection limit was 2.4 x 10(-7) M at a signal-to-noise ratio of 3.     

基于掺杂压电薄膜的FBAR制备及研究

薄膜体声波谐振器(FBAR)具有体积小、工作频段高、性能强等优势,在滤波器领域有广泛的应用前景,其最核心的功能层为压电薄膜.本文采用磁控溅射方法,在6英寸硅片上制备了AlScN压电薄膜.对AlScN薄膜进行了分析表征,结果表明,AlScN压电薄膜具有良好的(002)面择优取向,摇摆曲线半峰宽为1.75°,膜厚均匀性优于0.6;,薄膜应力为10.63 MPa,薄膜应力可调.制作了基于AlScN压电薄膜的FBAR谐振器,其机电耦合系数为7.53;.在AlN中掺杂Sc能够有效提高压电薄膜的机电耦合系数,对研究FBAR滤波器的宽带化有重要意义.     

紫外光下纳米TiO2 薄膜亲水性机理的电化学研究

The nanometer films of TiO2 were prepared by sol-gel method on ITO（Indium-tin oxide,SnO2:In） substrate. The TiO2 film was the anatase phase with a particle size of 100 nm from the measurements of X-ray diffraction and AFM（Atomic-Force-Microscope）. Electrochemical characteristics of ITO/ TiO2 electrode under UV（ultraviolet）irradiation were investigated using the method of cyclic voltammetry. A new oxidative peak was observed at 0.035 V when the TiO2 electrode was irradiated by 253.7 nm UV light for a certain time. The peak current increased with the irradiation time. It was assumed that the new oxidative peak resulted from Ti3+,which was formed during the UV illumination. The changes of hydrophilicity of the TiO2 thin film on ITO under UV light were also observed. It was assumed that the changes of hydrophilicity of the films may be related with the formation of Ti3+ on the surface when the film was irradiated by UV light.