共查询到20条相似文献,搜索用时 15 毫秒
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SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were systematically characterized, and their gas sensing properties were investigated. Results showed that Co3O4 modification significantly enhanced the sensing performance of SnO2 nanofibers to ethanol gas. For a sample with 1.2 mol% Co3O4, the response to 100 ppm ethanol was 38.0 at 300℃, about 6.7 times larger than that of SnO2 nanofibers. In addition, the response/recovery time was also greatly reduced. A power-law dependence of the sensor response on the ethanol concentration as well as excellent ethanol selectivity was observed for the Co3O4/SnO2 sensor. The enhanced ethanol sensing performance may be attributed to the formation of p-n heterojunctions between the two oxides. 相似文献
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Lihua Lou Jilong Wang Yong Joon Lee Seshadri S. Ramkumar 《Particle & Particle Systems Characterization》2019,36(9)
The photodegradation of poly(vinylidene fluoride) (PVDF)/titanium oxide (TiO2) nanofibers under visible light is described, something that has not been previously reported in the literature. Visible light photocatalytic electrospun PVDF/TiO2 nanofiber webs with anatase TiO2 concentration varying from 0% to 20% (0%, 1%, 3%, 5%, 10%, and 20%) are produced, and their ability to degrade a toxic pollutant, Rhodamine B (RhB), is studied. Photodegradation study using UV–vis spectroscopy on PVDF/TiO2 nanofiber webs (with TiO2 concentration of 20%) shows that 80% of RhB is degraded within 6 h at the wavelength of 546 nm, which clearly falls within the visible spectra. The color of RhB solvent catalyzed by PVDF/TiO2 nanofiber webs gradually changes from red to orange, then to yellow, further to light yellow till colorless, which suggests the complete photodegradation of RhB under visible light. To estimate the rate of photodegradation, the reaction constant k is calculated. Based on the k value, PVDF/TiO2 nanofiber webs with 20% TiO2 concentration show the highest degradation rate compared to other PVDF/TiO2 nanofiber webs and pure TiO2 nanoparticles. This study proves the viability of TiO2‐based nanofibers to have catalytic capabilities under low‐energy visible light. 相似文献
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针对采用盖革模式雪崩光电二极管(Gm-APD)作为探测器的成像激光雷达,介绍了其测距原理及3D成像原理,并对如何提高其探测性能的方法进行了分析。以分析Gm-APD触发信号的统计特性为基础,对出现在距离门内不同位置目标的探测概率和虚警概率进行了研究与仿真,结果表明,目标处在距离门最前面时,探测概率受噪声水平影响最小,虚警概率受信号强度影响最大;目标靠近距离门中间位置时,探测概率随噪声水平增大下降缓慢,虚警概率随信号强度增大下降缓慢;目标处在距离门末尾时探测概率受噪声水平影响最大,而虚警概率几乎与回波信号强度无关。 相似文献
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无机物高温下微结构的研究 总被引:3,自引:1,他引:2
上海市钢铁冶金新技术开发应用重点实验室 ( SELF)的 U- 1 0 0 0型 Raman谱仪经过改造已能用两种方式在高温下进行测定。其一是由共焦显微镜 -显微加热台构成的“空间分辨法”。其二是利用电阻炉加热的“时间分辨法”。SELF正在进行冶金熔渣的微结构研究。这类物质的物性 (从冶金学考虑 ,首先是熔渣中的组元活度 )数据已有不少报道 ,但为了促进技术的发展 ,急需鉴别它们的可靠程度。并且 ,还有大量未定值的物性 (例如 :粘度、表面张力、介电常数、扩散系数等 )有待预测。而打通微观结构和宏观物性之间的渠道 ,则是解决上述问题的根本途径。本文介绍了 SELF在 <2 0 0 0 K条件下的 HTRS(高温 Raman谱 )实测和 DFT- MD计算机模拟两种研究手段 ,定量分析冶金熔渣微结构的基本思路以及若干初步的结果。事实上 ,冶金熔渣、地学中的岩浆、玻璃和陶瓷 ,乃致某些宝石都可认为是一大物类 ,所以 SEL F同时也正在进行着烯土类熔盐和功能晶体的研究。 相似文献
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A method to determine glucose using an optical sensor prepared by entrapping glucose oxidase into silica sol-gel column has been developed. The silica sol-gel film was coated on alumina substrate. The optical sensor is based on the chemiluminescence intensity from the reaction of periodate and hydrogen peroxide in K2CO3 medium. The effect of the ratio of water and alcohol for the preparation of TEOS sol on chemiluminescence intensity was investigated. The effects of pH of enzyme reactor, concentrations of potassium periodate and SDS, and flow rate on the chemiluminescence intensity were studied to find the optimum experimental conditions to determine glucose. The chemiluminescence intensity increased linearly with increasing glucose concentration from 5.0 x 10(-4) M to 1.0 x 10(-7) M and the detection limit was 4.0 x 10(-8) M. Interference effects from some metal ions on chemiluminescence intensity were also investigated. 相似文献
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(以CMOS图像传感器LUPA-1300-2为对象,研究了多斜率积分功能)在空间瞬态光探测系统中的应用.以ACTEL公司APA600 Flash型FPGA为硬件载体,分析设计了其驱动控制,验证了LUPA-1300-2的易操作性,结果表明,该功能可以降低系统的复杂程度和提高系统观测的动态范围,有利于观测瞬态光点周围的瞬间变化,从而提高系统的可靠性和信息收集能力. 相似文献
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Sathya Vijayakumar Srinivasadesikan Venkatesan Lee Shyi-Long Padmini Vediappen 《Journal of fluorescence》2022,32(4):1481-1488
Journal of Fluorescence - Pyridine based organic molecule as probe has been synthesized for the detection of phenylalanine (PA) biomarker. The synthesized probe is characterized by 1H and 13C NMR... 相似文献
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针对应用于生物体内特征物质检测与跟踪的电化学传感器的其智能化和集成化问题,本文提出了一种基于片上系统的支持实时数据自动检测的电化学传感器。首先,将应用于电化学传感器结构,通过将测量样品、检测溶液接口、多电极和检测传导器等单元集成在片上系统,结合信号转换和电源装置,实现电化学传感器的独立计算、存储和通信功能。接着,通过实现待测量物多电极、检测溶液电极子和单片机逻辑控制的协同计算满足自动检测需求。最后,基于数据整合与自动化处理设计了支持实时数据检测的电化学传感器。验证结果表明,在数据检测精度和实时性方面所提方案明显优于传统的非片上系统电化学传感器。 相似文献
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针对现有光纤电压传感器结构复杂、调整难度大、温度稳定性差、光功率损耗大及电压引入不便等问题,提出一种基于全偏振态检测且无需起偏器与检偏器的光纤电压传感器.传感器只含有自聚焦透镜、Bi4Ge3O12晶体以及全反射镜等3个主要元件,器件少,结构简单,对准较容易.介绍了全偏振态检测系统光路,采用分振幅法检测偏振态,具有快速响应、算法简单等优点.计算得出了偏振态、离线电场与被测电压之间的公式.进行了悬挂式高压试验,试验中的传感器上无电极,也无需接地,不但省去了昂贵的绝缘子,而且增大了传感器的量程.试验结果表明,在室温条件下0~10kV工频交流电压范围内,该传感器具有良好的线性关系,证明了该结构的可行性. 相似文献
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针对光纤光栅应变传感器接收信号弱且信噪比低这一问题,提出了应用DSP技术来抑制噪声,提高Bragg峰值波长检测精度的方法.实验结果表明所设计的498阶Kaiser窗低通FIR数字滤波器能够显著提高光纤光栅应变传感器的信号检测精度.采用DSP技术可以较好地解决光纤光栅传感器的波长解调这一技术难题. 相似文献