某病害地基的原因分析与加固方法应用研究

本文通过对某工程病害地基致害原因的详细分析,揭示了引发病害地基的常见原因,提出了树根桩加扩展式托换基础的加固、纠偏(倾斜)方法,在一定技术条件下,对软弱土病害地基和湿陷性黄土及其它特殊性土地基的加固治理效果十分显著,而且通过加固施工过程的有效控制,可降低或避免加固施工过程中的附加沉降和结构次生裂变。该方法对其它类似建筑物的不均匀沉降和倾斜的加固治理具有借鉴意义。

对进一步提高上海基层派出所信息化应用水平的思考

随着上海基层派出所信息化设施的基本建成,信息系统已覆盖了派出所主要业务领域,成为基层警务的日常手段。然而,信息化建设还存在诸多问题,势必影响到基层基础工作的进一步发展。因此,要进一步加强信息化综合管理,提高实战应用、普及应用水平,使信息化应用产生质的飞跃,在现代警务机制建设上先行一步。

提升基层电大教师信息化教学能力的策略研究

电大教育作为现代远程教育的主力军,它有一个明显的特点,那就是采用现代化教学手段进行教学,而现代化教学主要采用的是信息化教学媒介,掌握信息化教学方法成为每个电大教师必备的能力。笔者在基层电大工作多年,对基层电大的教师信息化教学手段的现状堪忧,本文从分析基层电大教师信息化教学能力的现状着手,论述了提升基层电大教师信息化教学能力的策略。

湖北省“四化”协同发展研究

以工业化、信息化、城镇化和农业现代化的替代指标,选取1980—2012年湖北省"新四化"指标变量的时间序列数据,对"新四化"变量发展水平时间序列进行ADF单位根检验、Johansen协整检验及Granger因果关系检验分析。结果表明,1980—2012年湖北省工业化、信息化、城镇化和农业现代化的指标变量对数一阶差分是平稳的,且在两个阶段存在长期协整关系;Granger因果关系检验随着湖北省社会经济发展,城镇化与农业现代化呈现出良好的互动关系,工业化对城镇化发展产生了较好的促进作用,信息化建设较为薄弱。

A review of real-time multi-GNSS precise orbit determination based on the filter method

Stable and reliable high-precision satellite orbit products are the prerequisites for the positioning services with high performance.In general,the positioning accuracy depends strongly on the quality of satellite orbit and clock products,especially for absolute positioning modes,such as Precise Point Positioning(PPP).With the development of real-time services,real-time Precise Orbit Determination(POD)is indispensable and mainly includes two methods:the ultra-rapid orbit prediction and the real-time filtering orbit determination.The real-time filtering method has a great potential to obtain more stable and reliable products than the ultra-rapid orbit prediction method and thus has attracted increasing attention in commercial companies and research institutes.However,several key issues should be resolved,including the refinement of satellite dynamic stochastic models,adaptive filtering for irregular satellite motions,rapid convergence,and real-time Ambiguity Resolution(AR).This paper reviews and summarizes the current research progress in real-time filtering POD with a focus on the aforementioned issues.In addition,the real-time filtering orbit determination software developed by our group is introduced,and some of the latest results are evaluated.The Three-Dimensional(3D)real-time orbit accuracy of GPS and Galileo satellites is better than 5 cm with AR.In terms of the convergence time and accuracy of kinematic PPP AR,the better performance of the filter orbit products is validated compared to the ultra-rapid orbit products.

Evaluation of Different Predictor Models for Detailed Soil Particle-Size Distribution

An accurate mathematical representation of soil particle-size distribution(PSD) is required to estimate soil hydraulic properties or to compare texture measurements using different classification systems. However, many databases do not contain full PSD data,but instead contain only the clay, silt, and sand mass fractions. The objective of this study was to evaluate the abilities of four PSD models(the Skaggs model, the Fooladmand model, the modified Gray model GM(1,1), and the Fredlund model) to predict detailed PSD using limited soil textural data and to determine the effects of soil texture on the performance of the individual PSD model.The mean absolute error(MAE) and root mean square error(RMSE) were used to measure the goodness-of-fit of the models, and the Akaike's information criterion(AIC) was used to compare the quality of model fits. The performance of all PSD models except the GM(1,1) improved with increasing clay content in soils. This result showed that the GM(1,1) was less dependent on soil texture.The Fredlund model was the best for describing the PSDs of all soil textures except in the sand textural class. However, the GM(1,1) showed better performance as the sand content increased. These results indicated that the Fredlund model showed the best performance and the least values of all evaluation criteria, and can be used using limited soil textural data for detailed PSD.