改性水玻璃浆液在粉细砂地层中注浆加固的应用

在合肥轨道交通2号线土建T J04标段的东一环路站到铜陵路站区间采用盾构接收施工的背景下,对复杂环境下采用改性水玻璃来注浆加固端头土体的关键技术进行阐释,准确分析盾构机在粉细砂层迸洞和出洞的注意事项和关键要点,这有利于施工人员针对性的施工,确保盾构机顺利进出洞.同时,这还能有效控制其对周边土质的影响,不致影响周边建筑的...     

Using three-dimensional models to teach molecular structures in high school chemistry

The purpose of this study was to compare the effects of using two- and three-dimensional model representations of molecular structures on student learning of organic chemical structures. Organic structures were taught to high school students using one of four methods of molecular representation: (1) two-dimensional textbook representations, (2) three-dimensional computer models, (3) three-dimensional ball and stick models, and (4) combination of the computer molecular models and the ball and stick models. The computer software used in this study wasMolecular Editor. Students in the combination group of using both computer and ball and stick models scored significantly higher on the retention test of isomeric identification compared to the other groups. Molecules were represented in this test in the same mode as the instructional representation. However, on a similar two-dimensional post-instructional test of isomeric identification, this group had a significantly lower mean than the other groups; the two-dimensional group had the highest mean. This difference was not observed with the two-dimensional retention test of isomeric identification. When given a two-dimensional test of isomeric construction, no significant difference was found among the group means with either the posttest or the retention test.     

工作面预注浆法治理矿井水灾害

根据山西团柏煤矿突水治理实例，简述工作面预注浆技术在矿井水灾害治理的应用，表述了实用的治理方案。     

On the fracture resistance of adhesively jointing structures

INTRODUCTION Adhesive bonding technology has been widely applied in modern structures in industries such as automotive, aerospace and in microelectronic device. The core idea of this technology is to bond two similar or dissimilar structure members with a thin continuous interface layer which can provide far better stress transfer across the interface than those traditional point-wise joining technologies such as spot welding, riveting and bolting. Furthermore, the damage tolerance proper…     

Using a cross section to train veterinary students to visualize anatomical structures in three dimensions*

A cross section was used to enhance three‐dimensional knowledge of anatomy of the canine head. All veterinary students in two successive classes (n = 124) dissected the head; experimental groups also identified structures on a cross section of the head. A test assessing spatial knowledge of the head generated 10 dependent variables from two administrations. The test had content validity and statistically significant interrater and test–retest reliability. A live‐dog examination generated one additional dependent variable. Analysis of covariance controlling for performance on course examinations and quizzes revealed no treatment effect. Including spatial skill as a third covariate revealed a statistically significant effect of spatial skill on three dependent variables. Men initially had greater spatial skill than women, but spatial skills were equal after 8 months. A qualitative analysis showed the positive impact of this experience on participants. Suggestions for improvement and future research are discussed. © 2002 John Wiley & Sons, Inc. J Res Sci Teach 39: 10–34, 2002     

粘土中桩侧摩阻力研究

采用主成分分析方法, 就粘性土多指标反映其性质的规律进行了研究. 研究表明, 采用液性指数作为单一指标的传统粘性土物理状态划分方法, 在反映亚粘土和亚砂土性质时不尽合理. 而采用液性指数IL结合孔隙比e反映粉质粘土的特性更加合理. 同样,孔隙比e比液性指数IL能更好地描述亚粘土的天然特性. 采用人工神经网络结合主成分分析, 得出应用孔隙比e和液性指数IL两个指标来预测桩侧摩阻力更为精确. 同时发现在一定临界影响深度范围内(20～30 m), 桩侧摩阻力随深度的增加而增加, 且粘性土的稠度愈硬, 临界深度愈浅.     

Applications of airtight concrete grouting to road tunnels

Road tunnel excavation often traverses coal strata,which is at risk of firedamp explosion that usually results in disaster.Airtight concrete grouting is popularly used in this kind of tunnel project,Based on the essential theory of mechanics of fluids in prous media,the principle of improving concrete airtight property and its influential factors are investigated.The proportioning tests and monitoring method for airtight concrete are introduced,which is illustrated by a case study applied to the project of the Huayinshan Tunnel.It is proved by engineering practices that the achievement of this research work is beneficial to tunneling project across coal strata.     

采用压密注浆技术处理公路软土路基沉降

对马鞍山湖西南路软土路基进行了稳定性分析及沉降计算 ,对不满足规范要求的路基 ,最后采用压密注浆技术进行工程处理。     

倒伏对春小麦品种(品系)籽粒灌浆特性及产量的影响

试验选取三类不同熟期的春小麦品种（品系），在同一时间倒伏后，分期对比测定各品种（品系）倒伏后不同发育阶段的籽粒鲜重、干重，比较分析品种（品系）倒伏与未倒伏籽粒的灌浆特性及干物质积累变化规律。结果表明：倒伏对不同品种（品系）籽粒干物质积累动态变化的差异显著性影响不同，对同一品种（品系）的最大灌浆速率及到达最大灌浆速率的时间均存在着影响，最终对籽粒产量存在着不同程度的影响。     

在"钻孔灌桩施工法"教学中如何培养学生的记忆力

记忆是学习的基础.本文介绍了用异同比较、相反相成比较及列表比较的方法增强学生理解记忆力的做法,并以“钻孔灌桩施工法“教学为例,阐述了该教法的实践和体会.     

在加拿大拦了市长的车

前不久,我和儿子去表姑家玩,表姑在加拿大维多利亚一所中文学校当老师。她带着我们游览了当地的海洋研究中心、博物馆和天文物理观察站。维多利亚市是加拿大不列颠哥伦比亚省的省会,位于加拿大西南的温哥华岛的南端,是温哥华岛上最大的城市和不冻港。     

桩端压力注浆补强大直径灌注问题桩案例研究

根据桩端压力注浆机理,对某工程大直径灌注问题桩进行补强处理.文章主要阐述了加固处理的程序,以及在处理过程中需要特别注意的某些质量控制环节,最后展示其试验检测结果.检测结果表明:桩端压力注浆可以有效地提高大直径灌注桩中的一些问题桩的单桩极限承载力;虽然很难确定其提高承载力幅度的具体数值,但仍不失为处理该类桩中问题桩的一种有效方法.     

高压旋喷技术在建筑工程中的应用

概述了高压旋喷技术的特点、工艺参数，并结合工程实例，说明高压旋喷技术的应用前景。提出对该项技术的一些建议和看法。     

工业电视监控系统在福建水口I升船机的应用探讨

工业电视监控系统是一种计算机控制的图像系统,经多次技术变革,已完全进入高科技领域．近年来．福建水口升船机工业电视监控系统通过技术改造,利用数字网络和计算机局域网技术的优势,形成了控制使捷的新一代网络视频系统,现结合该系统对工业电视监控系统应用进行初步探讨．     

桥梁基础工程中基于CPTu的粘性土不排水抗剪强度确定方法

为了给南京长江四桥基础工程设计与分析提供可靠的长江漫滩粘性土不排水抗剪强度Su参数,采用国外引进的孔压静力触探(CPTu)测试系统进行了现场原位试验,并以高质量土样的室内试验作为参考,对几种基于CPTu的Su确定方法进行了对比与评价,同时对所提出的圆锥系数Nk值进行了验证.试验结果表明:圆锥系数Nkt,Nke,N△u的...     

A simplified nonlinear calculation method to describe the settlement of pre-bored grouting planted nodular piles

The pre-bored grouting planted nodular (PGPN) pile is a type of composite pile foundation that is considered to be environmentally friendly and economical. A simplified approach, which considers the two interfaces of the pile shaft, was proposed to analyze the load-displacement response of a single PGPN pile. An elastic-failure model, based on the shear test results, was used to simulate the shearing behavior of the concrete-cemented soil interface. A hyperbolic nonlinear model, considering the influence of cement paste injection, was created to simulate the behavior between the skin friction and the relative displacement developed along the cemented soil-soil interface. A linear model and a nonlinear model that considers the reduction in the shearing stiffness were used to simulate the PGPN pile base load-displacement responses in a field test and in a model test, respectively. Comparisons between the calculated and measured load-displacement responses revealed relatively good agreement. The proposed approach is thus shown to be efficient and suitable for the analysis of a single PGPN pile embedded in layered soils, and is used to analyze the factors influencing its behavior. Enlarged cemented soil base is considered to be effective in promoting the behavior of a short PGPN pile, while increasing the diameter of cemented soil along the shaft is efficient in promoting the compressive bearing capacity of a long PGPN pile.     

建构主义在ERP沙盘综合模拟实验教学中的应用研究

该文探讨了在建构主义教学理论指导下开展ERP沙盘综合模拟实验教学,通过对企业实际运作的模拟,使学生在参与中进行专业知识的学习,体验复杂、抽象的管理理论和决策方法在实践中的运用。教学实践证明,这是一种十分有效的经济管理专业实践教学方式,能有效地帮助学生强化专业知识学习、掌握管理技巧、锻炼分析和解决实际问题的能力,有助于培养学生的综合素质和创造能力,取得了良好的教学效果。