Conformations and adsorption behavior of poly（allylamine hydrochloride） studied by single molecule force spectroscopy

Poly（allylamine hydrochloride） （PAH）, which is frequently used in fabricating polyelectrolyte multilayer films, was studied by single molecule force spectroscopy （SMFS）. Plenty of force-extension curves with a long plateau were obtained in water, indicating that train-like structure was predominant when PAH was adsorbed on the substrate. It was found that the peak-type force-extension curves of PAH in water were not able to be fitted by the modified freely-jointed chain model. Additionally, there was a flat region in the derivative of force-extension curves. Thus, it was inferred that PAH chain in water was in a special conformation and underwent a ＂conformational transition＂ under the stretching of an external force. This phenomenon did not appear in the SMFS experiment in 1 mol/L urea solution, which indicated that urea was able to break the special conformation.     

Verification of GRAPES unified global and regional numerical weather prediction model dynamic core

During the past few years, most of the new developed numerical weather prediction models adopt the strategy of multi-scale technique. Therefore, China Meteorological Administration has devoted to developing a new generation of global and regional multi-scale model since 2003. In order to validate the performance of the GRAPES （Global and Regional Assimilation and PrEdiction System） model both for its scientific design and program coding, a suite of idealized tests has been proposed and conducted, which includes the density flow test, three-dimensional mountain wave and the cross-polar flow test. The density flow experiment indicates that the dynamic core has the ability to simulate the fine scale nonlinear flow structures and its transient features. While the three-dimensional mountain wave test shows that the model can reproduce the horizontal and vertical propagation of internal gravity waves quite well. Cross-polar flow test demonstrates the rationality of both for the semi-Lagrangian departure point calculation and the discretization of the model near the poles. The real case forecasts reveal that the model has the ability to predict the large-scale weather regimes in summer such as the subtropical high, and to capture the major synoptic patterns in the mid and high latitudes.     

系统寿命分布估计中的模式识别

在由多个指数分布组成的元件系统中,给出系统的分布函数将有助于对系统的寿命特征进行更精细的研究.利用Gibbs抽样法给出了混合指数分布的极大似然估计和最大后验估计.通过引进识别变量,对系统寿命数据进行分类识别,从而更好地监控系统中各元件的工作状况,为系统的可靠运行提供保证.     

数码显微互动网络教室在病理学教学中的应用

实验课是病理学教学的一个重要环节,我院于2006年将数码互动教学模式引入病理学教学,采用多媒体课件、多媒体数码互动系统、病理切片及大体标本观察等手段,发挥教学过程中"教师启发、学生参与、师生互动"的作用,扩展病理学实验的深度和广度,提高实验教学质量。     

单片机课程任务驱动教学模式探讨

本文介绍了目前高校单片机原理课程教学所存在的局限性,传统的教学模式不能发挥学生的学习兴趣,通过完成任务的教学方法,解决学生学习过程中的问题以实现对知识的掌握,意在改进教学模式,促进教学改革,把教学和实践相结合,培养学生创新能力。     

Dynamic study on water stability of soil structure and soil characteristics of several types of soils in southwest China

Three suborder soils in southwest China were adopted, namely Ustic Vertisol, Stagnic Anthrosol and Ustic Ferrosol, so as to carry out the basic physical and chemical analysis respectively, to design a dynamic measuring method for water stability of soil structure and conduct the comparative study on the quality of the soil structure. The results indicated that （1） The water stability dynamic characteristic of the soil structure could well reflect the maintaining capability of the soil structure as time goes on. （2） The quality of several soil structures in southwest China was sequenced as follows： Stagnic Anthrosols 〉 Ustic Vertisols 〉 Ustic Ferrosols. （3） The water stability of soil structure is very positively correlated with the capillary porosity and the clay particle （D 〈 0.002 mm） content （Co）, but is very negatively correlated with the silt （D is 0.05-0.002 ram） content （Csc）, and （4） The dynamic functional equation of the water stability of soil structure in southwest China was established, so that the water stability characteristics of various soil structures could be quantitatively expressed and the quality of different soil structures can be quantitatively compared from each other.     

文化预设及其翻译对策

文化预设是沉积于源语及源语读者心中的文化因素,是指导原语读者世界观、生活方式及行为方式的基本准则,这无疑是翻译实践中的一大障碍。本文对文化预设的含义、特点和功能等方面进行了研究,并得出结论：对于源语与目的语的不同的文化预设,译者要采取各种翻译策略以求在译文中最大限度地重构源语文化预设,帮助目的语读者消除阅读中出现的意义真空,建立语义连贯,达到跨文化沟通的目的。