Characteristics of low-leakage deep-trench diode for ESD protection design in 0.18-/spl mu/m SiGe BiCMOS process

This paper proposes a novel low-leakage BiCMOS deep-trench (DT) diode in a 0.18-/spl mu/m silicon germanium (SiGe) BiCMOS process. By means of the DT and an n/sup +/ buried layer in the SiGe BiCMOS process, a parasitic vertical p-n-p bipolar transistor with an open-base configuration is formed in the BiCMOS DT diode. Based on the two-dimensional (2-D) simulation and measured results, the BiCMOS DT diode indeed has the lowest substrate leakage current as compared to the conventional p/sup +//n-well diode even at high temperature conditions, which mainly results from the existence of the parasitic open-base bipolar transistor. Considering the applications of the diode string in electrostatic discharge (ESD) protection circuit designs, the BiCMOS DT diode string also provides a good ESD performance. Owing to the characteristics of the low leakage current and high ESD robustness, it is very convenient for circuit designers to use the BiCMOS DT diode string in their IC designs.     

Effect of oxygenation on electrocatalysis of La0.6Ca0.4CoO3−x in bifunctional air electrode

A vacuum-annealed La_0.6Ca_0.4CoO_3−x was consecutively oxygenated in air at temperatures decreasing from 800 to 100 °C, and its electrocatalytic activities for oxygen reduction and evolution were then measured as a function of the oxygenation temperature. The valence of Co cation, changing between +2 and +3, was found susceptible to annealing either in vacuum or air. The catalytic activities initially decrease monotonically as the oxygenation temperature was decreased from 800 to 300 °C, as a result of increasing oxygen content, and then rise abruptly with the oxygen reduction activity reaching a maximum at 200 °C and the oxidation activity at 150 °C. X-ray photoelectron spectroscopy analysis indicated that the enhancements by the low-temperature oxygenation involved increased OH coverage and less charged cations at surface. The results clearly reveal the importance of the post-calcination annealing process for optimizing the performance of La_0.6Ca_0.4CoO_3−x in air electrode applications.     

一种微透镜阵列的研制

介绍一种利用表面张力的作用、以光纤作材料、用分离的自聚焦透镜制作微透镜阵型的方法，这种方法具有制作工艺简单、无须昂贵设备等优点，用此方法实际制作了具有良好连续面型的微透镜阵列，并对制作的微透镜阵列进行了测试，效果较好。     

硫化氢吸收液的电化学分解条件研究

理想的脱硫工艺应满足体积小、费用低、净化度高、无二次污染等要求。在碱性溶液吸收微量硫化氢时同步进行电解，可有效减小设备体积，并将硫化氢转变为氢气和硫磺，不产生恶性气味。为此，实验研究了温度、浓度、电流密度、pH值等因素对电解阳极过程的影响，确定了适宜的电解条件，并在该条件下进行了吸收实验。结果表明，在最佳电解条件下，硫化钠溶液能充分吸收天然气中经变压吸附提浓的硫化氢（800 mg/m³），吸收率大于99.9％。     

LD端面抽运掺Yb3+双包层光纤激光器自脉动行为的实验研究

本文对连续波半导体激光器端面抽运的Fabry-Perot腔掺Yb3 双包层光纤激光器的自脉动输出行为进行了研究．发现低Q值腔光纤激光器具有两种形式的自脉动输出，一种是饱和吸收被动调Q产生的自脉冲,另一种是与光纤中的受激Raman散射(SRS)效应相对应的阵发性巨脉冲．通过提高光纤激光器谐振腔的Q值并选择合适的抽运功率，可以有效地减小输出功率的自脉动，获得稳定的连续波激光输出．     

Theoretical analysis of cladding-mode waveguide dispersion and its effects on the spectra of long-period fiber grating

A new method to control the free spectral range (FSR) of a long-period fiber grating (LPFG) is proposed and theoretically analyzed. As the refractive index decreases radially outward in the silica cladding by graded doping of fluorine, waveguide dispersion in the cladding modes was modified to result in the effective indexes change and subsequently the phase-matching conditions for coupling with the core mode in a LPFG. Enlargement of the FSR in a LPFG was theoretically confirmed.     

Improvement of AlGaInP light emitting diode by sulfide passivation

The brightness of AlGaInP light emitting diodes (LEDs) has been raised by a factor of 1.12 at 20 mA by sulfide passivation. Meanwhile, the sulfide also can decrease leakage current of AlGaInP LEDs at -2 V to nearly one thousandth of that in the as-fabricated device. The possible causes for the brightness increase of AlGaInP LEDs after sulfide treatment including surface roughness, reduction of Fresnel loss, and effective injection of carriers were demonstrated.     

Estimation of the Longitudinal Dispersion Coefficient Using the Velocity Profile in Natural Streams

In this study, a theoretical method for predicting the longitudinal dispersion coefficient is developed based on the transverse velocity distribution in natural streams. Equations of the transverse velocity profile for irregular cross sections of the natural streams are analyzed. Among the velocity profile equations tested in this study, the beta distribution equation, which is a probability density function, is considered to be the most appropriate model for explaining the complex behavior of the transverse velocity structure of irregular natural streams. The new equation for the longitudinal dispersion coefficient that is based on the beta function for the transverse velocity profile is developed. A comparison of the proposed equation with existing equations and the observed longitudinal dispersion coefficient reveals that the proposed equation shows better agreement with the observed data compared to other existing equations.     

洼60-H26水平井套铣打捞技术

洼60-H26井是一口中曲率水平井,设计井深1 922 m,由于地面条件的限制,设计采用三维井眼轨道。该井水平段在钻至井深1 801 m时,发生卡钻事故。在卡钻事故处理过程中,采用测卡、爆炸松扣技术取出上部钻具后,应用了不同规格的套铣管对被卡钻具进行套铣,采用间歇式套铣方式实现了大斜度井段(45°-90°)的安全套铣,采用短套铣管完成了时水平井段内φ215．0 mm稳定器的套铣,采用φ228．6 mm套铣管成功套铣水平井段被卡LWD仪器,最后通过震击器震击成功解卡。详细介绍了洼60-H26水平井卡钻事故的处理过程,分析了在水平段处理卡钻事故的难点。该井处理卡钻事故的经验,对以后水平井施工中处理井下事故、打捞贵重仪器具有借鉴价值。     

布帮鞋无浆贴合工艺技术

本工艺是对原有工艺的改进，突破了原有布帮鞋不能采用无浆贴合的局限性，对原有工艺中的不足有了很大的改进，提高了生产效率，改善了鞋子外观质量，增加了鞋子的美观性。