InAs/GaAs quantum dot infrared photodetectors with different growth temperatures

InAs/GaAs quantum dot infrared photodetectors were fabricated with quantum dots grown at three different temperatures. Large detection wavelength shift (5–14.5 μm) was demonstrated by changing 40 degrees of the epitaxy temperature. The smaller quantum dots grown at lower temperature generate 14.5 μm responses. The detectivity of the normal incident 15 μm QDIP at 77 K is 3 × 10⁸ cm Hz^1/2/W. A three-color detector was also demonstrated with quantum dots grown at medium temperature. The three-color detection comes from two groups of different sizes of dots within one QD layer. This new type of multicolor detector shows unique temperature tuning behavior that was never reported before.     

A New Modal Lindström Theorem

We prove new Lindstr?m theorems for the basic modal propositional language, and for some related fragments of first-order logic. We find difficulties with such results for modal languages without a finite-depth property, high-lighting the difference between abstract model theory for fragments and for extensions of first-order logic. In addition we discuss new connections with interpolation properties, and the modal invariance theorem. Mathematics Subject Classification (2000): Primary 03B45; Secondary 03C95     

105K工作温度的多元长波光导碲镉汞探测器

文章报道了空间多光谱扫描仪红外波段多元光导碲镉汞探测器的研制与优值。重点研究并解决了多元器件光谱曲线不一致性的问题，简述了器件的优值波段响应率RΔλ1，波段探测率DΔλ和单色响应率Rλ的测试定标方法，以及器件按空间环境使用要求经历老炼和环境条件试验的情况。测试结果表明多元件性能稳定可靠，各项指标均达到了空间多光谱扫描仪的技术要求。     

流延热释电厚膜陶瓷制备单元红外探测器

本文报道采用流延法制备的热释电厚膜陶瓷材料直接装配的单元红外探测器，该方法大大简化了目前探测器的制备工艺，极大地提高了材料的利用率，器件的性能也达到了目前探测器的水平。     

WIDE RANGE DETECTOR USING PARABOLIC CYLINDRICAL MIRROR FOR THz APPLICATIONS

A new, wide-band, high-speed and high-sensitivity THz detector has been developed. The prototype detector consists of a parabolic cylindrical mirror, a long wire antenna and a Schottky barrier diode. Direct detection measurements have shown a stable sensitivity of 150 ± 50 V/W for 1–2 THz without any adjustments. The long wire antenna was fixed at the focus of parabolic cylindrical mirror then it has been realized less operation steps, easy coupling to the external THz signals and a dramatic enhancement in the practicality of this system. The optically polished mirror and frosted surface one showed comparable sensitivities, thus easy polishing and less cost mirror fabrication can be applied for this system. The radiation pattern showed a maximum radiation angle of approximately 23° with its dominant main lobe, which was attributed to the wire antenna character and confirmed good agreements with classical antenna theory.     

工业CT图像均匀性校正

在工业CT图像重建过程中,射束硬化使得图像出现“杯状”伪影,阵列探测器响应不一致使得图像出现环状伪影、带状伪影和点伪影,影响图像均匀性.本文分析了射束硬化的原理和探测器响应不一致的数学模型,并通过实验,对探测器响应进行多挡板定标得到校正系数表.利用查表插值的方法对投影数据进行均匀性校正,消除上述伪影.     

非标准色传感器引起的颜色误差分析

本文推导了两种非标准色传感器在测色时引入的误差公式,并对其进行分析。最后通过计算8个样品的颜色对分析结果给于验证。     

PVInSb红外探测器的阻抗——频率特性分析

通过理论计算和实际测试，给出了ＰＶＩｎＳｂ红外探测器的低频阻抗－频率特性曲线，结合检测阻抗／动态电阻的方法和阻抗－频率特性曲线的变化规律，分析讨论了ＰＶＩｎＳｂ红外探测器的阻抗与动态电阻的异同，从而说明在涉及ＰＶＩｎＳｂ红外探测器的阻抗／动态电阻时，即使在低频范围也要具体考虑频率因素的影响。     

汽车组合仪表板控制系统设计

介绍了以PIC16F873单片机为控制核心的汽车组合仪表板控制系统的设计,简述了汽车组合仪表板的基本构成,介绍了汽车组合仪表板控制系统的组成和各部分功能,给出了数据采集处理电路、电源电路等部分硬件电路设计方案,并阐述了一些软件设计算法,如分段插补法和用于平滑指针的软件设计算法等。     

20μm高灵敏浸没型碲镉汞红外探测器

报道了一种新型高灵敏浸没型ＨｇＣｄＴｅ红外探测器的研制，获得了Ｄ＾＊＝１．４６×１０＾１１ｃｍＨｚ＾１／２Ｗ＾－１，Ｒ＝６０８Ｖ／Ｗ，λｃ（２０％）－２０μ，灵敏元面积Ａ＝０．１２×０．１２ｍｍ＾２，和有效通光孔径ψ＝６ｍｍ的浸没型器件。