退火温度对纳米氧化铜湿敏性能的影响

湿度传感器在生产和生活中扮演着不容小觑的角色,越来越受到人们的广泛关注.本文利用低温液相法以氢氧化钠、过硫酸铵和铜粉为原料,成功制备出氧化铜纳米结构.运用扫描电子显微镜(SEM)、X-射线衍射仪(XRD)等技术对材料的结构与形貌进行表征,发现可以通过退火温度来调控氧化铜纳米结构的表面形貌,进一步比较研究了不同退火温度下制备的纳米氧化铜的湿敏性能.并将CuO纳米材料涂敷在电极表面制成了湿敏元件.研究结果表明,元件的湿敏特性明显与材料的退火温度密切相关,在500℃退火获得的氧化铜纳米线灵敏度最高,达到1.93×10~5;湿滞最小,几乎为零;感湿频率特性曲线的线性度好.分析认为这主要是由于,退火温度500℃时,氧化铜呈现纳米线状结构,具有更大的表面积,增加了与水分子的接触面积,进而具有更佳的湿敏特性.     

湿敏陶瓷感湿机理的新模型讨论

本讨论了湿敏陶瓷感湿机理比较接近于实际的“镶嵌模型”，对“镶嵌模型”的线性方程进行了求解，并对结果进行了分析，为各种多孔陶瓷湿敏元件的开发提供了新途径。     

电阻型高分子湿敏元件的光辐射改性研究

电阻型高分子湿敏元件在氦氖激光、太阳光、紫外光辐照一定的时间后，用在不同湿度下测量辐照前后的电阻值来分析元件性能的变化，在较长的时间内跟踪测量来观察其长期稳定性。结果表明，湿敏元件在氦氖激光照射一定时间后，其感湿特征量的线性和长期稳定性匀变好。     

湿敏半导体陶瓷感湿机理的理论新模型

本详细论述了湿敏半导体陶瓷的微观感湿机理，讨论了比较接近于实际的“镶嵌模型”，给出了新模型的理论方程，为各种多孔陶瓷湿敏元件的开发提供了新的理论依据。     

湿度传感器的可靠性研究

本文详细分析了湿敏陶瓷的微观结构和感湿机理,阐述了引起陶瓷湿敏元件性能漂移的因素和机理。     

碳湿敏膜的非线性感湿特性和导电机理

采用羟乙基纤维素（HEC）和导电炭黑并添加山梨醇增湿剂制备碳湿敏膜,研究了膜在偏离结露区的非线性感湿特性和导电机理.扫描电镜观测到,膜中炭黑粒子形成网链状的空间导电结构;2%炭黑含量使膜的导电通路处于渗流区,膜电阻在80%RH附近对湿度有较强的非线性特性.分析I-V曲线认为,是导电网链中炭黑粒子的间距使膜电阻对湿度变化和测量电压的变化都非常敏感,非线性感湿特性与导电机理密切相关.复阻抗谱表明,碳湿敏样品在33%RH时只出现与炭黑体电阻有关的半圆弧,在80%RH时出现与炭黑粒界电 关键词： 碳湿敏膜 逾渗阈值 I-V特性')" href="#">I-V特性 复阻抗谱     

BaTiO3粉料的温敏性质

实验发现,ＢａＴｉＯ３粉料压片的电阻和电容具有湿敏特性,粉料颗就寸减小时敏感度增高,响应时间加快。     

多壁碳纳米管膜湿敏特性的研究

研究了多壁碳纳米管(MWNTs)薄膜的湿敏特性，实验所用的多壁碳纳米管是用热灯丝化学气相沉积法(CVD)合成的.分别对未修饰和修饰的多壁碳纳米管膜温度和湿度特性进行研究后发现，修饰的多壁碳纳米管对温度和湿度非常敏感，且对湿度的响应时间和恢复时间短，重复性好.而未修饰的多壁碳纳米管对温度和湿度不太敏感.对修饰多壁碳纳米管的湿敏特性进行了理论分析，给出了其理论表示式. 关键词： 多壁碳纳米管 化学修饰 湿敏特性 物理吸附     

BaTiO_3粉料的湿敏性质

实验发现， ＢａＴｉＯ３ 粉料压片的电阻和电容具有湿敏特性． 粉料颗粒尺寸减小时敏感度增高， 响应时间加快．     

大范围光纤Bragg光栅压力传感器增敏实验研究

鉴于钛合金材料具有低弹性模量、受温度影响小等特性,设计制作了一种以钛合金管作为光纤Bragg光栅应变增敏衬底元件的高压压力传感器件.通过与电阻应变计实时监控的对比,从实验上研究了光纤Bragg光栅的中心波长偏移对调谐压强的响应.结果表明:这种增敏设计,具有良好的线性响应和可重复性,且与理论推导结果吻合较好.增敏后对压力的响应灵敏度可达0.034 nm/MPa,测压量程可达0~40 MPa,甚至更宽.     

LCD投影系统光学引擎的计算机仿真分析

光学引擎是决定LCD投影系统色度、光度品质的核心部件之一。根据投影系统光学引擎的结构特点，结合色度学原理，利用光路追踪法编制了光学引擎的色度、光度仿真分析软件。仿真分析软件具有双向功能：对引擎的光学系统可进行色度光度计算，并可根据色度、光度指标优化光学引擎结构。将仿真与实际的光学引擎进行了对比实验，得到多组投影视场的色坐标对比数据，最后用软件优化了一个光学引擎，得到该引擎结构的优化数据。实验结果表明：该软件可提高光学引擎的设计效率。     

光纤布拉格光栅嵌入SMS光纤结构的湿度传感器

提出了一种基于光纤布拉格光栅嵌入单模-多模纤芯-单模(single-mode-multimode fiber core-single mode, SMS)光纤结构的湿度传感器。当环境湿度变化时,SMS光纤结构的干涉光谱会发生漂移,而光纤布拉格光栅对湿度不敏感,其纤芯基模保持不变。因此利用SMS光纤结构对环境湿度的敏感性去调制光纤布拉格光栅纤芯基模,通过检测光纤布拉格光栅纤芯基模的反射能量变化就可以实现湿度测量。数值模拟了SMS光纤结构的内部光场分布规律,理论计算了不同环境折射率时,多模纤芯的长度、直径对SMS光纤结构输出能量耦合系数的影响。理论模拟表明,随着环境折射率变化,SMS光纤结构中传输的纤芯基模的输出能量耦合系数会发生变化。同时制作了传感器样品并对其进行了传感实验研究,实验结果表明多模纤芯长35 mm、纤芯直径为85 μm的传感器在45%～95%RH湿度变化范围内,湿度灵敏度为0.06 dBm·(%RH)-1。在20～80 ℃温度范围内,传感器的温度灵敏度为0.008 nm·℃-1,温度所带来的湿度测量误差为0.047%RH·℃-1。传感器具有制作简单、灵敏度高、反射式能量检测等优点,在湿度测量领域有一定的应用价值。     

Relative humidity sensor based on SMS fiber structure with polyvinyl alcohol coating

A novel relative humidity (RH) sensor based on single-mode–multimode–single-mode (SMS) fiber structure is presented. The sensors are created through coating a thin layer of polyvinyl alcohol (PVA) on the multimode fiber deleted the cladding trough HF solution cauterization as the sensitive cladding film, whose refractive index varies as a function of humidity level. Due to the SMS fiber structure's sensitivity to ambient refractive index, the transmission spectra of SMS fiber structure coated PVA film are modified under exposure to different ambient humidity levels ranging from 30% to 80% RH. The related numerical simulations of transmission spectra of SMS fiber structure with different surrounding refractive index are also proposed. The sensitive of the RH measurement of 0.09 nm/% RH in the range from 30% to 80% RH is experimentally achieved. Meanwhile the intensity of wavelength at 1543 nm is decreasing as the humidity increasing. The experimental results obtained are consistent with the conclusion obtained by numerical simulating.     

Improving the sensitivity of a humidity sensor based on fiber bend coated with a hygroscopic coating

A highly sensitive all-fiber humidity sensor is demonstrated. The sensor behaves as a humidity dependent optical switch between 85% and 90% RH. This sensor also offers the advantages of simple structure and low cost and its response is fast and reversible in nature. The typical humidity response of the sensor is suitable for using it as a human breath rate monitor.     

汽车座椅局部散热除湿研究

车内空气的温度和相对湿度是影响人体舒适性的重要因素。特别是在高温条件下,高湿对人体的影响更加明显。使用计算流体力学和计算传热学的方法,对座椅和人体接触面温湿度较高的问题进行分析。根据人体及汽车座椅的相关尺寸,建立座椅的计算模型,然后进行数值计算。从改变结构的方面考虑解决问题的途径,即在座椅与人体接触面下开槽,并强制通风。使用FLUENT软件进行数值模拟,选择k-ε模型求解温度场和湿度场。计算结果表明,这种方法可以降低汽车座椅与人接触区域的温度和相对湿度,提高局部热舒适性。所得数据为车室内人体局部热舒适性评价提供理论依据。     

MIS structure with polyamide insulator under the conditions of water vapor sorption

A silicon MIS structure with sulfonate-containing aromatic polyamide as a gate insulator is prepared with the aim of using it as a capacitive-type humidity detector. A detector made of this material offers a high sensitivity at an elevated relative humidity and a high speed of response. Measurements of the capacitance of the structure at different frequencies basically make it possible to determine the water distribution in the polymer matrix. The high-frequency (1 MHz) capacitance versus relative humidity dependence (i.e., the calibration curve of the detector) is typical of the isotherms of water vapor sorption by similar polymers.     

Humidity sensor based on a single-mode hetero-core fiber structure

Using a small-core single-mode fiber (SCSMF), a novel relative humidity (RH) sensor based on an SMF28-SCSMF-SMF28 fiber structure was proposed in this paper. By depositing a humidity sensitive material, such as poly (ethylene oxide) (PEO) on the bare SCSMF fiber, the proposed structure can act as an RH sensor with high sensitivity. Experiments demonstrated that the proposed RH sensor with PEO coating can achieve a sensitivity of 430 nm per relative humidity unit (RHU) in the RH range from 80% to 83% RH and a sensitivity of 50 nm per RHU in the RH range from 83% to 95% RH.     

Intense ion-beam dynamics in the NICA collider

The problems of intense ion-beam dynamics in the developed and optimized optical structure of the NICA collider are considered. Conditions for beam collisions and obtaining the required parameters of luminosity in the operation energy range are discussed. The restriction on collider luminosity is related to effects of the domination of the space charge and intrabeam scattering. Applying methods of cooling, electron and stochastic ones, will permit one to suppress these effects and reach design luminosity. The work also deals with systems of magnetic field correction and problems of calculating the dynamic aperture of the collider.