珠海市陆海统一高精度高程网的建设与实现

珠海市陆海统一高精度高程网的建设与实现,是利用域内收集到的526个重力资料以及25个高精度GPS水准数据,采用第二类Helmert凝集法建立的1㎝级精度似大地水准面。高程网的精度可满足四等水准甚至三等水准的要求。这将改变传统的平面和高程测量分离的作业模式,实现平面高程测量同步一体化的现代化方法。     

台湾“老街”探游

提起台湾的观光景点,各地的“老街”无疑是一道闪亮的风景线。无论是地处台湾北部面向太平洋的淡水老街,还是因一曲《鹿港小镇》而蜚声中外的鹿港老街,都成为了游人首选的地点。台湾的“老街”因其特有的古老韵味、生活气息的浓厚而成为台湾地区在地文化的典型代表。本文对台湾“老街”形成原因、建筑特色进行归纳分析,通过实际案例调研探寻台湾地区对于街区整体保护与利用的做法与经验。     

非线性有限元法在出线装置复合绝缘结构电场计算中的应用

极性反转是换流变压器出线结构复合绝缘的一种特殊工作状态,极性反转时由于空间电荷作用可导致绝缘介质内部及界面处电场畸变。另一方面,绝缘介质电性能参数是温度的函数,因此温度梯度导致的电性能参数改变同样会影响绝缘结构在极性反转过程中的瞬态电场分布。基于此,为了较准确地模拟复合绝缘结构在考虑温度分布条件下的极性反转瞬态电场,提出应用非线性有限元法对以上2种瞬态电场影响因素进行耦合分析。首先研究了油浸纸复合绝缘体系电性能参数与温度的关系;然后详细介绍了基于非线性有限元法的瞬态电场计算流程,并通过双层同轴复合绝缘结构模型验证了其有效性;最后对实际换流变压器出线装置的油纸-环氧浸渍典型复合绝缘结构建立了二维轴对称仿真计算模型,在考虑材料非线性的条件下对其极性反转瞬态电场变化过程进行了仿真分析。计算结果表明传统模拟方法与考虑材料非线性时的结果存在较大差异,且极性反转过程中复合绝缘结构易出现畸变严重的局部高场强区。     

Potentiometric and Thermodynamic Studies of (N-[-(4-Chlorophenyl) Methylene]Nicotinohydrazide) and Its Transition Metal Complexes

Abstract

Pharmacologically active organic ligands (N-[-(4-chlorophenyl) methylene] nicotinohydrazide) synthesized through the condensation of equimolar mixture of anti-mycobacterial agent (nicotinohydrazide) with aromatic aldehyde. The reaction progress and purity of organic ligands were verified by thin layer chromatography. Formation of organic ligands was confirmed with the help of MP, IR, ¹H NMR, 13C NMR and elemental analysis. Further formation of complexes of transition elements such as Mn(II), CO(II), Ni(II), Cu(II) and Zn(II) with organic ligand (Schiff base) N-[-(4-chlorophenyl)methylene] nicotinohydrazide were studied by the pH-metric technique at 25?°C, 35?°C and 45?°C in 70% (v/v)ethanol – water medium at 1?M (NaClO₄) ionic strength. The stability constants of these binary complexes were evaluated and order of stability constant found as Co (II) < Mn (II) < Ni (II) < Cu (II) < Zn (II). The thermodynamic parameters associated with the complexation reactions also were calculated. It is found that the change in enthalpy (ΔH) and change in Gibb’s free energy (ΔG) were negative for all of the systems which suggested that all of the reactions were exothermic. The change in entropy (ΔS) found positive for most of the complexes which indicate in metal-ligand binding process is entropy favorable.     

城市轨道交通车辆段上盖物业开发项目设计阶段的成本管控研究

分析城市轨道交通车辆段上盖物业开发项目的特点及设计要求,从健全部门组织机构、完善设计合同条款、优化专业设计方案、做好开发周期计划角度,提出车辆段上盖物业开发项目设计阶段成本管控的要点,以期为类似项目的开发提供借鉴与参考。     

基于海绵城市理论的小城镇低影响开发设计初探--以扶沟县高铁新区方案设计为例

传统的城市开发模式导致城市化问题日益严重。本文在新型城市化背景下,通过分析我国小城镇水环境现状,结合海绵城市理论对低影响开发视角下小城镇规划设计进行思考,提出了从流域、街区、地块三个层面解决小城镇水环境问题的规划思路,并以河南省扶沟县高铁新区方案设计为例进行深入探讨。     

基于数值模拟和Mindlin解的煤矿井塔纠偏研究

基于Mindlin应力解的桩筏基础、土钉墙、岩石锚杆等的理论计算及应用较多,但是对与煤矿井筒刚性连接的井塔进行纠偏处理在实际工程中比较少见。应力解除法在房屋纠偏中得到了良好的运用而在井塔纠偏中还无先例。应用有限元数值模拟和弹性力学Mindlin解2种方法对井塔应力解除纠偏进行验证。通过考虑土体开挖卸荷比对Mindlin解影响而对其进行修正,得到的结果与有限元数值模拟结果一致,可以验证:应力解除法能够有效运用于井塔纠偏;增大应力解除区宽度、减小应力解除孔到井筒的距离、适当增加应力解除孔深度和增大应力解除孔孔径可以有效提高纠偏效果。     

Children’s Parks in Lisbon’s urban spaces: a childhood education and assistance programme during the Portuguese dictatorial regime (1933–1974)

This article deals with how a female member of the elite from the period of the Portuguese dictatorial regime (1933–1974) used Lisbon’s gardens to implement a free childhood education and assistance programme for poor children – the Children’s Parks programme. The Children’s Parks were located in some of Lisbon’s most attractive gardens, housed in pavilions that were directly connected to outdoor spaces. These spaces responded to the educational purposes of the programme, based on the importance of leisure and play activities in outdoor spaces and linked to children’s moral, social, and physical development. In considering the living conditions experienced by children within the context of the Portuguese dictatorship, and by highlighting the way in which these were reflected at the level of architecture and the urban space, the paper seeks to contribute towards an understanding of the place of the child in the history of architecture and urbanism. Besides reflecting the social and educational identity of the project, the urban and architectural settings of the programme were crucial for its success. The interpretation of this case provides a basis for reflecting on the historical and current significance of children’s spaces, and for examining a number of social, educational, architectural, and urban questions.     

Response of Aspergillus flavus,Aspergillus niger and Penicillium citrinum to oxidative stress induced by Fenton’s reagent

The presence of fungi in water systems represents a threat to human health. Hydrogen peroxide is known for its disinfecting properties and easy decomposition to water and oxygen. Its activity can be enhanced by the addition of iron as a catalyst, a reagent known as Fenton?s reagent. In the present study, different Fenton concentrations were investigated on the spores of Aspergillus flavus, Aspergillus niger and Penicillium citrinum at different time intervals. The results indicate that complete inactivation of spores was noticed after 60 min of exposure to both 2 and 3% H₂O₂ catalyzed by 0.025 g Fe²⁺/100 ml for A. niger, and 3% H₂O₂ catalysed by 0.075 g Fe²⁺/100 ml for P. citrinum. The activity of two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), was determined in mycelial mat harvested after 7 days. Their activities were either highly increased or reached their minimum values prior to inactivation of spores.