Deep levels,electrical and optical characteristics in SnTe-Doped GaSb Schottky Diodes

The GaSb layers investigated were grown directly on GaAs substrates by molecular beam epitaxy (MBE) using SnTe source as the n-type dopant. By using admittance spectroscopy, a dominant deep level with the activation energy of 0.23-0.26 eV was observed and its concentration was affected by the Sb₄/Ga flux ratio in the MBE growth. A lowest deep-level concentration together with a highest mobility was obtained for GaSb grown at 550°C under a Sb₄/Ga beam equivalent pressure (BEP) ratio around 7, which should correspond to the lowest ratio to maintain a Sb-stabilized surface reconstruction. In the Hall measurement, an analysis of the temperature-dependent mobility shows that the ionized impurity concentration increases proportionally with the sample’s donor concentration, suggesting that the ionized impurity was introduced by an SnTe source. In addition, optical properties of an undoped p-, a lightly and heavily SnTe-doped GaSb layers were studied by comparing their photoluminescence spectra at 4.5K.     

有机-无机复合肥生产工艺

随着社会经济快速发展和城乡环境的污染已日趋严重。根据有机肥、无机肥各自的优缺点提出有机-无机肥生产的新工艺。     

有机盐聚合醇氯化钾钻井液的应用

霍尔果斯背斜构造极其复杂,内应力极高,地层倾角大,断层、破碎带多,并存在高低压互层;安集海河组的灰绿色软泥岩水化严重并具有粘弹塑性.该区块重点探井霍003井三开、四开井段选用有机盐聚合醇氯化钾钻井液,同时为保证钻井液在高密度下（2.55 g/cm^3）具有好的流变性,使用活化铁矿粉、活化重晶石加重.应用结果表明,由于采用了强抑制和多元封堵的措施,该钻井液具有良好的流变性和较强的携带能力,钻进中曾携带出重2.8 kg和5.1kg的大掉块;滤失量低,泥饼质量好,封堵能力强,造壁能力强,减轻了井下阻卡程度;有良好的储层保护能力;在室内研究的基础上,经过现场合理使用和维护钻井液,霍003井提高了机械钻速,缩短了钻井周期,井身质量优于邻井.指出在高密度下,未选出适合有机盐聚合醇氯化钾钻井液的稀释剂,钻井液流动性较差.     

可见光共振腔发光二极管的研究进展

共振腔发光二极管是一种具有优良发光性能的光电器件。概述了对可见光共振腔发光二极管的共振腔结构、反射镜材料体系、基本工作机理和发光特性，并展望了这种器件的发展前景。     

Variations in Spectral Slope in Lake Taihu,a Large Subtropical Shallow Lake in China

Spectral slope (S), describing the exponential decrease of the absorption spectrum over a given wavelength range, is an important parameter in the study of of chromophoric dissolved organic matter (CDOM) dynamics, and also an essential input parameter in remote sensing models. Furthermore, S is often used as a proxy for CDOM composition, including the ratio of fulvic to humic acids and molecular weight. The relative broad range in S values reported in the literature can be explained by the different spectral ranges and fitting methods used. A single exponential model is used to fit the S values for 17 investigations involving 458 samples in Lake Taihu from January to October in 2004. The average S value was 15.18 ± 1.39 μm⁻¹ for the range of 280–500 nm, which fell within the range reported in the literature. The frequency distribution of S value basically obeyed a normal distribution. Significant differences in S values between summer and other seasons showed that phytoplankton degradation was one of the important sources of CDOM in summer, whereas CDOM mainly came from the river input in other seasons. Furthermore, the estimated S value decreased with increasing wavelength range used in regression. The maximum and minimum values derived from the regression were 17.89 ± 1.25 μm⁻¹ and 13.62 ± 2.11 μm⁻¹ for the wavelength ranges of 280–380 nm and 400–500 nm, respectively, a decrease of 23.9%. S values significantly decreased with the increase of CDOM absorption coefficients. CDOM absorption coefficients could be more appropriately estimated from exponential model introducing the variation of S with absorption coefficients, making them useful for a remote sensing bio-optical model of Lake Taihu. DOC-specific absorption coefficient a*(λ) and the parameter M describing molecular size of the humic molecules could also be used as a proxy for the sources and types of CDOM. A general relationship was found between S and a*(λ), and M values. S increased with the decrease of DOC-specific absorption coefficient and the increase of M corresponding to the decrease of molecular weight.     

轻质油中C1—C7轻烃的地球化学特征

作者对5个盆地18个轻质油样品作了C_1—C_7轻烃分析,检测出29种单体轻烃。通过轻烃组成特征研究,认识到石蜡指数(PI_1)和庚烷值(PI_2)作为成熟度的指标,不受沉积盆地类型影响;C_6,C_7烃类族组分受母质类型影响较大。陆相(含煤地层)有机质生成轻质芳烃(苯)的含量比海相有机质要高。新疆塔里木盆地沙参2井原油的轻烃分析资料表明,该井油源岩为海相沉积。     

蒸发油气污染的生物控制技术探讨

生物降解气态有机污染物的研究是近年来发展起来的大气污染控制新领域。通过介绍生物降解气态有机污染物的基本原理，探讨石油储运过程中的蒸发油气污染运用生物控制技术的可行性，提出需要解决的问题和研究的重点。     

Study on Dihydrated Praseodymium Acetylacetonate by Photoacoustic Spectra with Broad Wavelength Range

Photoacousticspectroscopy (PAS)hasbeenusedtonondestructivelyinvestigatealmostallkindsofsam ples,whetherthesampleiscrystalline ,powderorgel .PAspectr oscopyisacalorimetrictechniquewhichmeasurestheenergyabsorbedandsubsequentheatingofthesamplesduetoanonradiativerelaxationpro cess .ThereforePAScanbeusedtostudyopaque ,highlyreflectiveandscatteringsamples ,whicharedif ficulttostudybyconventionalspectroscopytech niques[1] .Withouttheneedofsamplepreparation ,PASavoidstheriskofsamplealteration ,pre…