既有建筑地基基础加固施工探析

随着建筑工程使用年限的增长,地基基础的质量问题也逐渐暴露出来。对既有建筑地基基础加固,是解决这类问题的良好办法。本文结合笔者多年的建筑施工经验,分析了原因。并提出了解决的措施,以供参考。     

论城市社区空间形态营造

社区是城市最重要的组成元素之一,该文将从社区规划的一个方向——社区空间形态营造方向入手,对社区空间及社区核心区的营造进行初步分析和研究。该文首先对城市社区空间营造提出相应的原则,并且在分析和研究的基础上总结出单核心型社区、双核心型社区、多核心型社区以及轴核心型社区四种城市社区空间形态类型,最后提出社区核心空间营造的要点。该文的分析与研究都是为了给社区规划中的社区的空间形态营造工作提供可参考的依据。希望借此文章为今后社区规划以及社区建设的研究一些积累宝贵的经验。     

矿山环境的水文地质问题

矿山在开采的过程中会对环境水文地质造成一定的影响,容易引发滑坡、泥石流等地质灾害的发生。因此探讨矿山环境的水文地质问题,对于预防和治理矿山地质灾害具有重要的意义。本文阐述了矿山环境水文地质问题的防治措施。     

基于CAD/CAE的拼焊板桶形件冲压成形工艺仿真分析

介绍拼焊板冲压成形的研究意义,并概述拼焊板桶形工件的成形特点,比较较为广泛用于材料成形的CAE工具,最后选取Dynaform软件作为研究工具,以有限元仿真作为分析方法对拼焊板桶形工件冲压成形工艺进行研究。     

盘式永磁电机的分数槽绕组齿槽转矩分析

由齿槽转矩造成的推力波动是影响盘式永磁电机运行性能的一个重要因素.为削弱齿槽转矩,采用基于能量法和傅里叶分解的解析分析方法推导出了齿槽转矩解析表达式,在此基础上研究了分数槽绕组对齿槽转矩的削弱作用,结合定子槽口宽度对齿槽转矩的影响,提出了减少盘式永磁电机齿槽转矩的优化方案,并利用有限元法对此优化方案进行了仿真分析和验证.研究结果证明,采用分数槽绕组和槽口优化相结合的方法能有效地削弱盘式电机的齿槽转矩.     

时效温度对非调质钢MFT8拉伸性能的影响

介绍了试验材料及方法,对冷拔非调质钢MFT8在不同温度下进行了时效处理,对试验结果进行了分析研究。分析结果表明,MFT8非调质钢具有较强的加工硬化能力,冷拔MFT8非调质钢经300℃时效后具有最佳的强度和塑性配合。     

直升机减速器润滑系统应急技术研究

直升机减速器润滑系统出现故障,齿轮轴承将处于无润滑油工作状态,使减速器在短时间内破坏,造成灾难性的后果.对直升机减速器润滑系统多种应急技术方案进行分析,指出这些方案的优点与缺陷,提出了更为全面更为先进的解决思路,如选用热强度高的材料;对传动元件进行表面改性;采用应急润滑系统;用油气润滑代替油雾润滑;使用硫系与磷系复合添加剂或其他在高速冲击和低速高扭矩条件下均具有良好抗磨性能的复合添加剂.     

Site‐specific accumulation and dynamic change of flavonoids in Apocyni Veneti Folium

Site‐specific accumulation of flavonoids in Apocyni Veneti Folium was determined by laser scanning confocal microscope (LSCM) and the localization of catechins also was observed via vanillin‐HCl staining under the conventional optical microscope. The contents of five flavonoids in Apocyni Veneti Folium from different harvest times and growth parts were measured using HPLC method. LSCM observation showed that flavonoids are accumulated in cuticle of epidermal cells and vessel walls, especially in protoplasts and nucleolus of the collenchyma cells and the epidermal cells. Catechins are localized in the palisade parenchyma cells and vessel walls, particularly in the laticifers found in the phloem. On the basis of the difference of the maximal emission wavelength between quercetin and kaempferol derivatives which have fluorescence behavior by appropriate treatment, kaempferol and its derivatives are localized exclusively in the cuticle. Results showed that the content of astragalin in Apocyni Veneti Folium from different parts revealed the decreasing trend, while hyperin and isoquercitrin were higher in June and July analyzed by HPLC. In summary, the site‐specific accumulation of flavonoids in Apocyni Veneti Folium can be determined by LSCM and vanillin‐HCl staining. The contents of flavonoids in Apocyni Veneti Folium are correlated with harvest times and growth parts.     

Antifatigue properties of dragonfly Pantala flavescens wings

The wing of a dragonfly is thin and light, but can bear high frequent alternating stress and present excellent antifatigue properties. The surface morphology and microstructure of the wings of dragonfly Pantala flavescens were observed using SEM in this study. Based on the biological analysis method, the configuration, morphology, and structure of the vein were studied, and the antifatigue properties of the wings were investigated. The analytical results indicated that the longitudinal veins, cross veins, and membrane of dragonfly wing form a optimized network morphology and spacially truss‐like structure which can restrain the formation and propagation of the fatigue cracks. The veins with multilayer structure present high strength, flexibility, and toughness, which are beneficial to bear alternating load during the flight of dragonfly. Through tensile‐tensile fatigue failure tests, the results were verified and indicate that the wings of dragonfly P. flavescens have excellent antifatigue properties which are the results of the biological coupling and synergistic effect of morphological and structural factors. Microsc. Res. Tech. 77:356–362, 2014. © 2014 Wiley Periodicals, Inc.     

气固两相流速度-浓度检测技术的研究分析

对气固两相流速度和浓度的间接检测方法、基本原理、应用范围及研究成果进行了论述.分析和总结了速度、浓度检测技术的发展现状和存在的问题.着重分析了浓度测量中静电法测量相浓度技术在工业应用中存在的问题及研究现状.给出了静电式相浓度传感器的设计准则,阐明了该传感器用于相浓度测量的优越性及其广阔的工业应用前景.