Application and realization of hierarchical network planning based on Web

Making use of Microsoft Visual Studio. NET platform, hierarchical network planning is realized in working procedure time-optimization of the construction by TBM. and hierarchical network graph of the construction by TBM is drawn based on browser. Then the theory of system realization is discussed, six components of system that can be reused are explained emphatically. The realization of hierarchical network panning in Internet provides available guarantee for controlling rate of progress in large-scale or middle-sized projects.     

黄壤供氮能力预测的研究

利用^15N稳定性同位素进行水稻、烤烟的盆栽与田间试验,结果表明,贵州黄壤的供氮能力可以用“A”值表示,不同海拔高度的土壤养分校正系数在0．2－0．3之间。     

Crosstalk model and estimation formula for VLSI interconnect wires

We develop an interconnect crosstalk estimation model on the assumption of linearity for CMOS device. First, we analyze the terminal response of RC model on the worst condition from the S field to the time domain. The exact 3 order coefficients in S field are obtained due to the interconnect tree model. Based on this, a crosstalk peak estimation formula is presented. Unlike other crosstalk equations in the literature, this formula is only used coupled capacitance and grand capacitance as parameter. Experimental results show that, compared with the SPICE results, the estimation formulae are simple and accurate. So the model is expected to be used in such fields as layout-driven logic and high level synthesis, performance-driven floorplanning and interconnect planning.     

A gene expression atlas of the central nervous system based on bacterial artificial chromosomes

The mammalian central nervous system (CNS) contains a remarkable array of neural cells, each with a complex pattern of connections that together generate perceptions and higher brain functions. Here we describe a large-scale screen to create an atlas of CNS gene expression at the cellular level, and to provide a library of verified bacterial artificial chromosome (BAC) vectors and transgenic mouse lines that offer experimental access to CNS regions, cell classes and pathways. We illustrate the use of this atlas to derive novel insights into gene function in neural cells, and into principal steps of CNS development. The atlas, library of BAC vectors and BAC transgenic mice generated in this screen provide a rich resource that allows a broad array of investigations not previously available to the neuroscience community.     

A defective response to Hedgehog signaling in disorders of cholesterol biosynthesis

Smith-Lemli-Opitz syndrome (SLOS), desmosterolosis and lathosterolosis are human syndromes caused by defects in the final stages of cholesterol biosynthesis. Many of the developmental malformations in these syndromes occur in tissues and structures whose embryonic patterning depends on signaling by the Hedgehog (Hh) family of secreted proteins. Here we report that response to the Hh signal is compromised in mutant cells from mouse models of SLOS and lathosterolosis and in normal cells pharmacologically depleted of sterols. We show that decreasing levels of cellular sterols correlate with diminishing responsiveness to the Hh signal. This diminished response occurs at sterol levels sufficient for normal autoprocessing of Hh protein, which requires cholesterol as cofactor and covalent adduct. We further find that sterol depletion affects the activity of Smoothened (Smo), an essential component of the Hh signal transduction apparatus.     

加快电子政务建设提高信息化管理水平

通过对电子政务发展瓶颈的分析,提出加快电子政务建设的思考建议:选准切入点,充分利用现有资源进行网站升级,配套进行行政体制改革,开展电子政务培训,构建科学电子政务绩效评估体系.     

航空摄影科技发展成就与未来展望

在过去的一个半多世纪,航空摄影测量取得了许多重大的成就,经历了模拟摄影测量阶段、解析摄影测量阶段和数字摄影测量阶段,革新了空间数据获取的技术方法,显示出了航空摄影巨大的生命力和影响力。文章介绍了国外航空摄影近几十年在数字摄影测量工作站、胶片航空摄影仪、数字航空摄影仪等方面取得的巨大成就。在航空摄影发展的历史中,我国数字摄影测量工作站也成为其具有典型代表性的标志。因应当前航空摄影测量的发展和应用需要,本文着重对具有自主知识产权的SWDC-4数字航空数码相机进行了阐述。文章最后讨论了航空摄影的3个发展趋势,意在与广大读者一起探讨航空摄影的未来。     

中频磁控溅射法制备氧化锌钇薄膜及其性能研究(英文)

利用中频磁控溅射法,溅射氧化锌钇(ZYO)陶瓷靶材,在玻璃基底上制备ZYO透明导电薄膜。研究了氧化钇掺杂量和基底温度对薄膜的结构、电学性能和光学性能的影响。结果表明,ZYO薄膜为钎锌矿型结构,呈c轴择优取向,平均可见光透过率(400～800nm)达到80%以上。制备的ZYO薄膜具有的最低电阻率为1.18×10-3Ωcm。     

面向学生的个性化智能型教学平台的构成和应用

本文结合“电大在线”教学平台和作者开发的个性化智能学习服务系统,依据现代教学设计理论和学习理论建立了面向学生的个性化智能教学平台的组成模块,分析了各模块的特点,并设计教学平台,支持面向学生的个性化教学。     

内蒙古荒漠草原土壤微生物的分布特征及季节动态变化研究

研究了内蒙古荒漠草原土壤中主要微生物类群的数量随季节变化的规律，以及土壤中微生物的垂直分布特征．结果表明，土壤中3大类群微生物的数量关系为细菌〉放线菌〉真菌，各类群微生物的垂直分布均为0～10cm层多于10-20cm层．细菌、真菌、自生固氮菌以及微生物总数量的峰值出现在春季，而放线菌数量的峰值出现在秋季．