陶瓷PTC与有机PTC的性能比较及应用

正温度系数的热敏电阻（ＰＴＣ）作为一种新型过流保护元件,近几年来已在程控交换机的用户接口电路防高压雷击、交流电搭接等方面得到了广泛应用。热敏电阻（ＰＴＣ）按制造材料可分为有机聚合物ＰＴＣ和陶瓷ＰＴＣ两大类。有机ＰＴＣ由高分子聚合物掺入碳粉经挤压成形。...     

降温速度及气氛对PTC元件特性之影响

通过工艺试验，研究了ＢａＴｉＯ３陶瓷ＰＴＣ材料在烧成过程中的冷却速度及烧成气氛对其ＰＴＣ特性之影响。试验结果表明：采用适当的缓冷速度及氧气氛烧成可大大提高材料的ＰＴＣ特性，αＴ、Ｒ（２００）／Ｒ（ｍｉｎ）明显增大，室温电阻达４５Ω左右。所制元件与日本样品性能相近，完全能满足开关型元件的要求。     

正温度系数热敏电阻烧结气氛的研究

研究了不同烧结气氛对正温度系数热敏电阻（ＰＴＣＲ）性能的影响，在ＣＯ２气氛下烧结的ＰＴＣＲ室温电阻率（ρ０）比在空气中烧结的低将近５０％，而其他各种电性能几乎没有明显的变化，因而在ＣＯ２气氛下的烧结是获得低电阻率ＰＴＣＲ的一种有效的工艺途径。     

热敏电阻PTC元件诚征合作伙伴

热敏电阻ＰＴＣ元件诚征合作伙伴本人研究热敏电阻ＰＴＣＲ系列元件历时５年，并对影响ＰＴＣＲ元件性能（如：ＰＴＣＲ效应、室温电阻率、耐压、恢复时间、老化性及居里温度的精确控制）等机理进行探索。找到了制造高性能、高稳定性的ＰＴＣＲ系列元件工艺和掺杂的途径。...     

利用表面等离子体可调谐滤色片的卷进式彩色投影显示

表面等离子体可调谐滤色器（Ｓｕｒｆａｃｅ Ｐｌａｓｍｏｎ Ｔｕｎａｂｌｅ ｆｉｌｔｅｒ,简作ＳＰＴＦ）,是喷气推进到正在开发的新技术。将ＳＰＴＦ用于ＬＣＤ投影机,可简化系统结构并提高效率。由三个ＳＰＴＦ组成的卷进式（ｓｃｒｏｌｌｉｎｇ）ＳＰＴＦ,可卷进地产生红（Ｒ）、绿（Ｇ）、蓝（Ｂ）三色,并能将单板ＬＣＤ投影机的效率提高到与三板ＬＣＤ投影机相同的水平。由６个ＳＰＴＦ组成的卷进式ＳＰＴＦ可以产生两     

正温度系数热敏电阻（PTCR）特性参数快速测试仪

本文介绍了一种快速测量正温度系数热敏电阻（ＰＴＣＲ）的重要参数（居里温度Ｔｃ和电阻温度系数αｔ）的测量方法，并根据这种方法设计了ＰＴＣＲ特性参数Ｔｃ，αｔ快速测试仪，该仪器的使用改变了传统测试方法时间长，工作量大的状况。通过测量ＰＴＣＲ在室温和两个特征温度下的电阻值，该仪器能很快计算并显示出Ｔｃ和αｔ的结果，大大提高了测试效率，该仪器以８０３１单片机系统为核心，简单实用，使用方便，成本低，文中介绍     

Mn(NO_3)_2掺杂BaTiO_3半导体材料特性

研究了用ＭｎＣＯ３粉末和Ｍｎ（ＮＯ３）２溶液两种掺杂方式引入受主Ｍｎ的ＢａＴｉＯ３半导体材料的宏观性能和显微结构。指出用Ｍｎ（ＮＯ３）２溶液二次掺杂能使Ｍｎ更均匀有效地富集在晶界,可提高材料的升阻比、温度系数和耐压强度,且对性能参数作用效率高,影响敏感,并有利于制取低阻的ＰＴＣＲ陶瓷材料。     

钛酸钡基陶瓷材料晶界掺杂与PTCR效应

“晶界掺杂”是一个全新的概念,它针对的是陶瓷晶界。在钛酸钡材料中,晶界掺杂能明显地改变ＰＴＣＲ效应。在晶界上,施主杂质同某些受主杂质一样,也可以明显提高材料的ＰＴＣＲ效应。通过晶界掺杂引入的Ｐｂ２＋则对ＰＴＣＲ效应有明显的损害。     

C-2CH复合型PTCR薄膜

采用溶胶包裹再凝胶工艺制备了Ｃ－２ＣＨ复合型ＰＴＣＲ薄膜。实验表明，这种材料的ＰＴＣ效应是由２ＣＨ的相变体膨胀引起的，Ｃ的粒径大小对复合薄膜ＰＴＣ特性有十分显著的影响。较高的热循环温度和较多的热循环老化次数使ＰＴＣＲ薄膜电性能重现性得以改善。     

一台离子注入机的改进及其在BaTiO3陶瓷改性中的应用

本文介绍了武汉大学２００ｋｅＶ离子注入机的改进情况，用贝纳斯离子源替换了原有的高频离子源，使输出流强由几十微安提高到毫安级，离子种类由原来单电荷的气体离子扩展到多电荷离子和金属离子。用该机对半导体ＢａＴｉＯ３陶瓷注入Ｃｕ离子，使材料的ＰＴＣＲ突跳幅度增加，室温电阻率提高，证实Ｃｕ（２＋）离子在ＰＴＣＲ材料晶界起着电子陷阱作用。     

基于超材料的自由电子辐射研究进展

自由电子与周围电磁环境互作用时可以通过不同的形式辐射电磁波.超材料是一种人工复合材料,可实现传统自然材料所不具备的电磁特性.基于超材料与自由电子之间的相互作用可以打破传统电磁辐射系统的限制,实现对辐射电磁波的极化、相位、波前等特性的灵活操控,这为发展新型的自由电子辐射器件提供了新思路.本文简单介绍了切伦科夫辐射、史密斯...     

基于红外热像波段拓展的多光谱成像研究

红外目标多光谱图像为目标红外辐射特性的研究提供了有效的手段,在目标材质识别、伪装目标辨识和复杂背景抑制等目标探测技术领域有着极为重要的应用。以黑体辐射理论为基础,提出了一种基于波段拓展的红外多光谱成像的方法。首先,利用中波红外热像仪（3～5 μm）采集红外图像,通过目标表面的真实红外辐射反推出热图像中不同像素点的温度值,然后利用普朗克公式可以获得不同像素点在预拓展波段处的辐射出射度数值,最后根据这些数值进行红外多光谱成像。     

Study of the charge collection efficiency of CdZnTe radiation detectors

The charge collection efficiency of CdZnTe radiation detectors with two different configurations: aSchottky diode detector and aresistive detector are compared. The average charge collection efficiencies for three different directions of irradiation (negative electrode, positive electrode and perpendicular to the electric field) are calculated. The mobility-lifetime product of the CdZnTe substrates is evaluated from the dependence of the measured spectra upon detector bias voltage. The measurement of the average charge collection efficiency is based on monitoring the shift of the peak channel with bias voltage in an experimental setup which is well calibrated. Two types of radiation are used:gamma photons from several radioactive sources andalpha particles from an²⁴¹Am source. The models for the evaluation of mobility-lifetime product from the measured data for the two types of detector configurations as well as for the two types of radiation sources, are compared and discussed. The CdZnTe (Zn = 10%) substrates under study are obtained commercially and are grown by the high pressure Bridgeman method. The mobility-lifetime products and specific resistivity of the two types of detectors are evaluated and compared. A lower resistivity material has a narrower depletion region and behaves like a thinner detector thus exhibiting better collection efficiencies. Therefore, medium resistivity material which is completely inadequate for resistive detectors can still yield high performance Schottky detectors. The preferred direction of irradiation, i.e. from the negative electrode, is possible only in the case of n-type material which is reverse biased by negative voltages applied to the Schottky gate. The mobility-lifetime products that are derived on both the resistive detector (with specific resistivity of ≈1.10¹⁰ ω.cm) and the Schottky diode (with specific resistivity of ≈1.10⁶ Ω.cm) are μ_nτ_n ≈-4.10⁻⁴ cm²V⁻¹ and μ_pτ_p≅ 8.10⁻⁵ cm²V⁻¹.     

红外泡沫陶瓷的研制

红外泡沫陶瓷是一种用途广泛的新型陶瓷材料,它的研究和开发,对红外加热技术有重要的意义。本文探讨了制备红外泡沫陶瓷的工艺条件及提高制品性能的途径。     

Thermally stimulated current measurements on a UV irradiated organic photoreceptor layer

Thermally stimulated current (TSC) measurements have been performed on a xerographic photoreceptor which has been treated with ultraviolet (UV) radiation. The charge transport layer of the photoreceptor consists of a polyester molecularly doped with an arylamine substituted hydrazone which was observed to undergo UV induced rearrangement to an indazole derivative. The indazole derivative is transparent to the wavelength component inducing the photo-reaction so that the depth of converted material gradually extends farther into the CTL with UV exposure time. The xerographic residual potential variation with irradiation time is attributed to the formation of a potential barrier to transfer of charge from hydrazone hopping states to indazole hopping states. The mobility activation energy obtained from TSC measurements is 0.22 eV for unirradiated material, which decreases to 0.12 eV after 1200 s of irradiation. The latter energy is identified as a signature of the potential barrier. This identification is corroborated by the correlation between the decrease of the residual potential and the increase of the TSC activation energy after 3600 s of irradiation.     

红外辐射与物质的热作用

关于红外辐射加热物质的研究和应用已经有许多年的历史了，把这一问题作为工程热物理内容来研究辐射与物质相互作用，曾经提出并应用了多种方法，也在实践中取得了很多经验和成果，并为国家节能事业做出了很大贡献。简要总结有关的内容。     

抗总剂量辐射0.8μm SOI CMOS器件与专用集成电路

介绍了采用全剂量SIMOX SOI材料制备的0.8μm SOI CMOS器件的抗总剂量辐射特性,该特性用器件的阈值电压、漏电流和专用集成电路的静态电流与高达500krad(Si)的总剂量的关系来表征.实验结果表明pMOS器件在关态下1Mrad(Si)辐射后最大阈值电压漂移小于320mV,nMOS器件在开态下1Mrad(Si)辐射后最大阈值电压漂移小于120mV,器件在总剂量1Mrad(Si)辐射后没有观察到明显漏电,在总剂量500krad(Si)辐射下专用集成电路的静态电流小于5μA.     

左手介质在增强电偶极子辐射功率上的应用

基于严格的电磁场理论,给出了左手介质壳包围电偶极子后的辐射场本征函数级数解.应用该级数解求解出该情况下的辐射功率,并与自由空间中电偶极子辐射场进行了比较,指出了左手介质在增强电偶极子辐射功率上的应用,并运用微波电路理论对该特性进行了分析验证.     

Facile Single‐Precursor Synthesis and Surface Modification of Hafnium Oxide Nanoparticles for Nanocomposite γ‐Ray Scintillators

Inorganic nanoparticles/polymer nanocomposites provide a low cost, high performance alternative for gamma scintillation. However, inorganic nanoparticles used thus far suffer from either moderate atomic numbers or low band gaps, limiting the gamma stopping power and photoelectron production in these systems. Here, a highly efficient, facile single‐precursor synthesis protocol is reported for hafnium oxide nanoparticles with an average diameter of 5 nm. The nanoparticle surface is further functionalized for the fabrication of highly transparent bulk‐size nanocomposite monoliths (2 mm thick, transmittance at 550 nm >75%) with nanoparticle loadings up to 40 wt% (net hafnium wt% up to 28.5%). Using poly(vinyltoluene) as the matrix, 2‐(4‐tert‐butylphenyl)‐5‐(4‐biphenylyl)‐1,3,4‐oxadiazole and 1,4‐bis(5‐phenyl‐2‐oxazolyl)benzene as the cascade fluors, and hafnium oxide nanoparticles as the gamma sensitizer, the nanocomposite monolith of 1 cm diameter and 2 mm thickness is fabricated capable of producing a full energy photopeak for 662 keV gamma rays, with the best deconvoluted photopeak energy resolution <8%.     

注F~+加固CMOS/SOI材料的抗辐射研究

向SIMOX材料的SiO2埋层或Si/SiO2界面注入170 keV F+,进而制成CMOS/SOI材料,采用60Co g 辐射器辐照并测量材料的I-V特性。结果表明:向CMOS/SOI材料埋层注入F+离子,能提高CMOS/SOI材料的抗电离辐照性能。而且,注入F+的剂量为11015cm2时,材料的抗辐照能力较强。这对制作应用于电离辐射环境的COMS/SOI器件极其有益。