A semi-analytical method for the analysis of pile-supported embankments

In this paper, a semi-analytical method for the analysis of pile-supported embankments is proposed. The mathematic model describes the cooperative behavior of pile, pile cap, foundation soil, and embankment fills. Based on Terzaghi??s 1D consolidation theory of saturated soil, the consolidation of foundation soil is calculated. The embankments with two different types of piles: floating piles and end-bearing piles are investigated and discussed. The results of axial force and skin friction distributions along the pile and the settlements of pile-supported embankments are presented. It is found that it takes a longer time for soil consolidation in the embankment with floating piles, compared with the case using end-bearing piles. The differential settlement between the pile and surrounding soil at the pile top is larger for the embankment with end-bearing piles, compared with the case of floating piles.     

决定论与非决定论的物理学基础以及逻辑刻画方法

自然科学的发展不但会使得人类对世界的认知不断加深,还会进一步影响哲学领域中的很多传统问题、甚至成为其科学基础。从物理学,特别是力学的不同分支出发,说明经典力学、量子力学、狭义相对论的发展对决定论以及非决定论的影响并在此基础上初步介绍其逻辑刻画方法。     

Confidence versus Performance as an Indicator of the Presence of Alternative Conceptions and Inadequate Problem‐Solving Skills in Mechanics

This study investigated the use of performance–confidence relationships to signal the presence of alternative conceptions and inadequate problem‐solving skills in mechanics. A group of 33 students entering physics at a South African university participated in the project. The test instrument consisted of 20 items derived from existing standardised tests from literature, each of which was followed by a self‐reported measure of confidence of students in the correctness of their answers. Data collected for this study included students’ responses to multiple‐choice questions and open‐ended explanations for their chosen answers. Fixed response physics and confidence data were logarithmically transformed according to the Rasch model to linear measures of performance and confidence. The free response explanations were carefully analysed for accuracy of conceptual understanding. Comparison of these results with raw score data and transformed measures of performance and confidence allowed a re‐evaluation of the model developed by Hasan, Bagayoko, and Kelley in 1999 for the detection of alternative conceptions in mechanics. Application of this model to raw score data leads to inaccurate conclusions. However, application of the Hasan hypothesis to transformed measures of performance and confidence resulted in the accurate identification of items plagued by alternative conceptions. This approach also holds promise for the differentiation between over‐confidence due to alternative conceptions or due to inadequate problem‐solving skills. It could become a valuable tool for instructional design in mechanics.     

新建师范本科院校量子力学课程教学初探

量子力学课程教学是本科阶段物理类师范专业最重要的课程之一,也是物理学课程教学的难点.本文结合自身在师范型高校的教学实践探讨了量子力学课程的若干教学方法.     

锁阳寄主-多裂骆驼蓬抗旱性能与应用潜力评价

通过对河西走廊多年生旱生植物多裂骆驼蓬的野外调查及室内实验,对其生物学特性、抗旱性能及应用潜力等方面进行了研究．结果表明：多裂骆驼蓬广布于河西走廊的戈壁滩、沙化沙砾、盐碱化荒地、黄土山坡及沟壑等环境中,是一种药用和生态治理相结合的特色植物,同时,它也是锁阳的另一寄主,可为锁阳的人工栽培研究提供新思路．因地制宜地进行合理开发利用,不但是荒漠化防治的优良植物,而且具有一定的药用潜力．     

水土保持是山丘区防治洪水灾害的根本措施——以黄冈麻城调查研究为例

麻城山丘区面积大,水土流失严重,洪水灾害频发。一段时间内,人们不合理地经济活动,破坏了自然植被,导致境内植被覆盖率降低,土地失去植被的庇护,水土流失加剧,造成洪水径流量和洪峰流量加大,加重了洪水灾害。二十多年的水土保持工作实践表明：以小流域为单元的水土保持综合治理工作,通过在流域内实施工程措施、生物措施和农耕措施相结合,坚持山、水、林、田、路统一规划,拦、截、灌、蓄、排优化配置,集中连片,规模治理,防范减灾效益显著。事实证明,水土保持工作是山丘区防治洪水灾害的根本措施。     

材料力学教学方法探讨

材料力学是工科专业开设的一门专业技术基础课。结合多年的教学经验,对材料力学课程教学方法进行了探讨。实践表明,研究内容对提高学生学习材料力学的兴趣,改善材料力学课堂教学效果有重要意义。     

易学与现代科学基本原理的一致性,量子易学和易热力学

现代科学和易学最基本原理都是对称性,包括广义守恒原理。讨论了易学整体应用于科学的结果,及与相对论的关系。并提出量子易学和相应的Schrodinger方程。新的探索显示出存在一种新的作用距离和强度都是中等的第五种相互作用。这种宏观的纠缠性,可能是一种天人关联态。预言易理可以应用两个符号L-R的SU(2)理论及相应的Yang-Mills规范场。最后提出易热力学,其联系于社会热力学。     

匀速转动参照系下伯努利方程式的推导

在匀速转动参照系下,当某一理想流体作定常流动时,选取一个任意形状流管,可以推导出其伯努利方程式：1/2ρv^2＋ρ（gy-1/2x^2ω^2）＋P=常数,利用该方程可以简便地处理流体匀速转动问题。     

Direct and relaxation methods for soil-structure interaction due to tunneling

This paper deals with the problem of tunneling effects on existing buildings. The direct solution, using the condensation method, is presented. This method allows the structural and geotechnical engineers to treat the problem separately and then assemble a relatively small matrix that can be solved directly, even within a spreadsheet. There are certain concerns that the resultant matrix may be ill-conditioned when the structure is very stiff. This paper suggests an alternative method that essentially relaxes the system from an infinitely rigid structure solution. As such, it does not encounter the problems associated with stiff systems. The two methods are evaluated for an example problem of tunneling below a framed structure. It is found that while the direct method may fail to predict reasonable values when the structure is extremely rigid, the alternative method is stable. The relaxation method can therefore be used in cases where there are concerns about the reliability of a direct solution.