Copper phthalocyanine catalysis to oxidation of adrenaline by oxygen and its application in adrenaline detection

The oxidation of adrenaline by dioxygen using copper phthalocyanine （CuPc） as the catalyzer was studied. CuPc has the optimal catalytic pH of 8.0 and the optimal catalytic temperature of 55 ℃. It also has good storage and operation stability. The fiber optic adrenaline biosensor based on CuPc catalysis and fluorescence quenching was fabricated and studied. This sensor has the detection range of 7.0 × 10^-5 1.5 × 10^-4mol/L, the response time of 4 rain, good reproducibility and stability.     

High‐Hardness Diamond Composite Consolidated by Spark Plasma Sintering

A high‐hardness diamond‐based composite was synthesized by spark plasma sintering (SPS) under 100 MPa, using SiC‐coated diamond powder prepared via chemical vapor deposition (CVD). SiC layers 20–40 nm were uniformly deposited on diamond powders by a rotary CVD technique. The SiC‐coated diamond powder was consolidated with SiO powder by SPS at the sintering temperature of 1873 K, resulting in the formation of fully compacted mosaic microstructure with the Vickers hardness of 36 GPa.     

融合L2范数最小化和压缩Haar-like特征匹配的快速目标跟踪

在贝叶斯推理框架下,基于PCA子空间和L2范数最小化的目标跟踪算法能较好地处理视频场景中多种复杂的外观变化,但在目标出现旋转或姿态变化时易发生跟踪漂移现象。针对这一问题,该文提出一种融合L2范数最小化和压缩Haar-like特征匹配的快速视觉跟踪方法。该方法通过去除规模庞大的方块模板集和简化观测似然度函数降低计算的复杂度;而压缩Haar-like特征匹配技术则增强了算法对目标姿态变化及旋转的鲁棒性。实验结果表明:与目前流行的跟踪方法相比,该方法对严重遮挡、光照突变、快速运动、姿态变化和旋转等干扰均具有较强的鲁棒性,且在多个测试视频上可以达到29帧/s的速度,能满足快速视频跟踪要求。     

Biocompatibility,physico-chemical and mechanical properties of hydroxyapatite-based silicon dioxide nanocomposites for biomedical applications

High-energy ball milling was employed to prepare carbonated hydroxyapatite/silicon dioxide (CHA/SiO₂) nanocomposites. Then, these nanocomposite powders were sintered at 900 and 1300 °C. XRD technique, FTIR spectroscopy and SEM were employed to examine the structure, molecular structure and microstructure of the sintered nanocomposites samples, respectively. Moreover, their mechanical properties were also measured. Furthermore, in vitro bioactivity and cytotoxicity of these nanocomposites were evaluated. The results indicated that the successive increases in SiO₂ contents led to remarkable enhancement for densification behavior, mechanical properties and in vitro bioactivity of nanocomposites sintered at 900 °C. However, further increase in the sintering temperature to 1300 °C caused dramatic decreases in density and mechanical properties of nanocomposites. On the contrary, better bioactivity behavior was achieved. Amazingly, the obtained results revealed that the sample having the highest content of SiO₂ and sintered at 900 °C had no toxic effects on bone-like cells while, that sintered at 1300 °C exhibited mild cytotoxicity. Based on the variations in the abovementioned properties, these nanocomposites can be used in different biomedical applications.     

葡萄糖氧化酶固定条件的优化

以醋酸纤维素(CA)为原料,采用溶液浇铸法成膜。用物理包埋法将荧光指示剂固定CA膜中。以戊二醛为交联剂,将葡萄糖氧化酶固定于膜表面。研究了高碘酸钠、乙二胺、戊二醛、给酶量、pH值等固定化条件对酶活的影响,确定了优化的固定条件:在室温下与0.5 mol/L的高碘酸钠反应30 min;与0.04 mol/L的乙二胺反应150 min时;与溶度为1.5%(v/v)的戊二醛交联120 min;在4℃条件下,在pH6.5、给酶量35 mg/mL的酶液中交联21 h。利用SEM分析表明,荧光指示剂均匀分布膜中,成膜质量较好。通过优化固定条件,把荧光指示剂和葡萄糖氧化物酶(GOD)同时固定醋酸纤维素膜上,可以得到同时具有光敏感性和酶催化能力的复合敏感膜。     

Photoconductivity of novel poly（N-vinyl）-3 - [p-nitrophenylazo] carbazole/ CdS-nanoparticle polymer composite

The photoconductive characteristic of the inorganic/organic hybridized polymer system is reported, in which a novel bi-functional photorefractive （PR） poly（N-vinyl）-3-[p-nitrophenylazo]carbazole （PVNPAK） serves as a polymeric charge-transporting and second-order nonliner optical matrix and quantum dots composed of surface passivated cadmium sulfide serve as a charge-generation sensitizer. The hybrid PVNPAK/CdS-nanoparticles polymer composites with different mass ratio of CdS to PVNPAK were prepared. The generation of photocurrent on illumination and photoconductive properties of the PVNPAK/CdS-nanoparticles polymer composites were studied. The results show that the addition of CdS nanoparticle as a photosensitizer can enhance the photoconductivity of the PVNPAK significantly because of the properties of the high quantum efficiency of photosensitization and high charge transport to conducting polymer.     

焦炉立火道光纤动态测温技术

焦炉炉温的动态监控对实时掌握焦饼成熟程度有着重要意义。结合焦炉温度测量的现状介绍了光纤双波长高温传感技术的原理及其消除外界因素对测温干扰的特点。由于焦炉是冶金工业中最复杂的窑炉,现场又处在腐蚀、雨水流入和火焰烧烤等恶劣工作环境,所以着重介绍了为适应该环境的特殊结构设计和工艺设计。光纤测温装置在焦炉55个立火道上测温的实际应用表明:光纤双波长测温技术准确,动态特性好,使用寿命可达1年。     

基于小波包的相位敏感OTDR分布式光纤振动信号降噪方法的研究

针对传统的基于相位敏感光时域反射计(-OTDR)的分布式振动传感系统在对外界振动信号降噪 效果方面的不足,提出了一种基于小波包的降噪优化方法:首先分析采集到振动点处信号的 特征并选取最 优基波Sym6,比对不同的基波分解层数对于原始信号降噪处理后的效果,从中选择三层分解 作为最优化分 解层数。其次对信号处理前后的信号进行傅里叶变换,通过频域比对证明小波包降噪方法能 够有效去除主 振信号以外的噪声。再次针对振动点附近的采集点进行了频谱分析,结果显示只有振动点对 应采集点的频 率与振动频率相同,从而证明了系统实际空间分辨率可达到1m。     

Structural characterization of CdS thin film on quartz formed by femtosecond pulsed laser deposition at high temperature

CdS thin films have been grown on quartz substrates using femtosecond pulsed laser deposition. The structural and optical properties of the CdS thin films were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The results indicate that the compositional segregation of the CdS films could be drawn from the selective evaporation of sulfur from the film surface as a result of heating up the substrates. Growth temperature played an important role on changing crystal structure and optical properties of the CdS films.