Optimized electrolyte for electrochemical capacitance-voltage profiling of carrier concentration in In0.49Ga0.51P

Electrolyte characterization and optimization for the electrochemical capacitance-voltage profiling of carrier concentration in In_0.49Ga_0.51P is presented. The conditions for operation under minimum electrolyte interference are found based on the complex impedance analysis of an electrolyte-semiconductor junction. Carrier concentration results obtained with the optimized electrolyte are shown to both provide good etch depth control and to agree with Hall measurements. The same optimization scheme may be used for the characterization of other semiconductor material.     

Comparative Metabolomic Study of Drosophila Species with Different Lifespans

The increase in life expectancy, leading to a rise in the proportion of older people, is accompanied by a prevalence of age-related disorders among the world population, the fight against which today is one of the leading biomedical challenges. Exploring the biological insights concerning the lifespan is one of the ways to provide a background for designing an effective treatment for the increase in healthy years of life. Untargeted direct injection mass spectrometry-based metabolite profiling of 12 species of Drosophila with significant variations in natural lifespans was conducted in this research. A cross-comparison study of metabolomic profiles revealed lifespan signatures of flies. These signatures indicate that lifespan extension is associated with the upregulation of amino acids, phospholipids, and carbohydrate metabolism. Such information provides a metabolome-level view on longevity and may provide a molecular measure of organism age in age-related studies.     

低钾胁迫对烟草幼苗碳氮代谢基因表达谱的影响

为探索烟草响应低钾胁迫的分子机制,对K326烟草幼苗进行了0、6、12和24 h的低钾胁迫处理,并利用定制的烟草全基因组芯片,分析了烟草幼苗基因表达谱的变化。结果表明,与0 h相比,6、12和24 h的3个时间点差异表达在2倍以上(p<0.05)的基因总数为3790个。从功能方面看,这些差异表达基因广泛参与了烟草的各种生物学过程,包括抗氧化活性、应激反应、运输活性、发育过程、催化活性、生物调节、代谢过程等。其中包括了硝酸还原酶基因NIA2等10个参与烟草氮代谢的基因,以及UGP等44个参与烟草碳水化合物与糖代谢的基因。本研究结果说明,低钾胁迫对烟草的基因表达产生了广泛的影响,进而可能影响到烟草的碳氮等基础代谢。     

Quantitative off-axis electron holography of GaAs p-n junctions prepared by focused ion beam milling

Focused Ion beam (FIB) prepared GaAs p-n junctions have been examined using off-axis electron holography. Initial analysis of the holograms reveals an experimentally determined built-in potential in the junctions that is significantly smaller than predicted from theory. In this paper we show that through combinations of in situ annealing and in situ biasing of the specimens, by varying the intensity of the incident electron beam, and by modifying the FIB operating parameters, we can develop an improved understanding of phenomena such as the electrically 'inactive' thickness and subsequently recover the predicted value of the built-in potential of the junctions.
PACS numbers: 85.30.De     

数据挖掘在CRM中的应用设计

讨论了在客户关系管理 (CRM)中用于客户细分和建立客户轮廓的数据挖掘技术。首先指出 CRM的概念和分类 ,然后分析了几种数据挖掘方法 ,最后提出面向 CRM的数据挖掘应用设计。