Quality of life in the regions: results for German Counties

In order to assess differences in living conditions across German regions we apply the hedonic approach of Rosen (Current issues in urban economics, 1979) and Roback (J Polit Econ 90(6):1257–1278, 1982) to land-price and wage differences across Germany’s counties. Employing a recent survey of more than half a million Germans on a wide range of social and political issues we confirm that differences in amenities give rise to substantial differences in land prices. With regard to wages, however, we find only little effects of amenities. Relying on the land-price effects we assess the quality of life in each of the German counties and provide a comprehensive ranking.     

Fatigue crack growth analysis of a square hollow section T-joint

Stress concentration sites are always found at the brace and chord intersection corners of any rectangular welded tubular joint. As a result, fatigue cracks are liable to be initiated and propagated from these corners. In this paper, the 3D fatigue crack growth under the weld toe of a square hollow section welded T-joint is simulated using boundary element method. In accordance with the 3D analyses, fatigue crack growth is predicted using a model based on the Paris’ law and stress intensity factors. Good agreement between the experimental and predicted crack growth and crack shape development is obtained. Based on this crack growth analysis, the fatigue life of a specimen is predicted and compared with the standard S-N curve for hollow section joints. It is found that the standard S-N curve is safe and slightly conservative.     

浅谈建筑电气节能的几点措施

文章介绍变压器的负荷率与变压器效率之间的关系;合理选择低压供电半径;采用成熟的新型节能电器设备、新材料、新技术等。     

An exergy application for analysis of buildings and HVAC systems

The paper presents an extended method for exergy analysis of buildings and Heating Ventilation Air Conditioning (HVAC) systems, according to an energy demand build-up model from the building side to the energy supply side. The HVAC systems comprise a thermal energy emission and control system, a thermal distribution system, an electricity distribution system and an energy conversion system. Energy and exergy that are required by a building and a HVAC system are posed into the external part and classified by different forms of energy carriers. The external part is out of the boundary of the study. The method is illustrated with an office building equipped with low-temperature heating and high-temperature cooling systems situated in the Netherlands. Thermal exergy and thermal energy demands of the building and thermal energy and thermal exergy losses occurring in the HVAC systems are discussed. The building and the HVAC systems to be considered meet standard Dutch energy performance regulations. Nevertheless their overall exergy efficiencies are low in both cases (17.15% and 6.81% subsequently). The exergy analysis also pinpoints that the thermal energy emission and control system and the energy conversion system are the main causes of the exergy inefficiencies in the heating and cooling cases, respectively.     

Numerical evaluation of wind effects on a tall steel building by CFD

A comprehensive numerical study of wind effects on the Commonwealth Advisory Aeronautical Council (CAARC) standard tall building is presented in this paper. The techniques of Computational Fluid Dynamics (CFD), such as Large Eddy Simulation (LES), Reynolds Averaged Navier-Stokes Equations (RANS) Model etc., were adopted in this study to predict wind loads on and wind flows around the building. The main objective of this study is to explore an effective and reliable approach for evaluation of wind effects on tall buildings by CFD techniques. The computed results were compared with extensive experimental data which were obtained at seven wind tunnels. The reasons to cause the discrepancies of the numerical predictions and experimental results were identified and discussed. It was found through the comparison that the LES with a dynamic subgrid-scale (SGS) model can give satisfactory predictions for mean and dynamic wind loads on the tall building, while the RANS model with modifications can yield encouraging results in most cases and has the advantage of providing rapid solutions. Furthermore, it was observed that typical features of the flow fields around such a surface-mounted bluff body standing in atmospheric boundary layers can be captured numerically. It was found that the velocity profile of the approaching wind flow mainly influences the mean pressure coefficients on the building and the incident turbulence intensity profile has a significant effect on the fluctuating wind forces. Therefore, it is necessary to correctly simulate both the incident wind velocity profile and turbulence intensity profile in CFD computations to accurately predict wind effects on tall buildings. The recommended CFD techniques and associated numerical treatments provide an effective way for designers to assess wind effects on a tall building and the need for a detailed wind tunnel test.     

工厂实用节电技术

阐述了工厂节电的意义以及所采取的方式和主要途径 ,着重提出了提高工厂功率因数和工厂负荷率的方法 ,分析了工厂经济运行电压对工厂节电的重要影响     

The Worker’s House

Abstract

The proto-sociologist Wilhelm Heinrich Riehl is best known in architectural history for the popularity that his organicist-functionalist dictum of “building from the inside out” received in early twentieth-century German architectural culture. However, less is known about Riehl’s own writing on architecture in the context of his sociological theories. This paper discusses the importance of Riehl’s thoughts on domestic architecture in giving theoretical elaboration to what, in the mid-nineteenth century, was a growing intellectual concern over the social position of workers. As the “worker” emerged as a distinct social type, and workers’ welfare registered as an increasingly pressing issue, Riehl’s call for a sociologically oriented understanding of architecture (capable of reforming the worker “from within”) significantly altered the terms of the debate over housing policy in Germany. In examining his theoretical elaboration of the task of social policy and the role of architecture within it, this paper reads Riehl’s work as a prelude to a new kind of logic about architecture’s social agency that would come to underpin modern housing reform.     

North–South transfers vs biodiversity conservation: a trade differential game

Trade relationships connect developed and developing countries. The former produces a consumption good, using labor, capital, and an intermediate “natural” good which is produced in the developing countries using labor and natural species. A finite horizon differential game is settled out. The North decides about either the saving rate or the portion of its disposable income to transfer to the South or both variables jointly. The South selects the range of species used in the production of the intermediate “natural” good required in the North’s productive process. This is a measure of biodiversity loss. The aim of the paper is to study how transfers from North to South affect capital growth and biodiversity conservation.

结构优化的APDL语言面向对象程序设计

引入面向对象技术机制，将结构优化问题运用类，对象，成员等概念进行数据抽象处理，在此基础上，编制APDL程序模块进行求解，算例表明，本文思想准确可行。     

6kV电机四星带间隙组合式过电压保护器的选型与试验

从真空开关操作过电压导致高压电动机绝缘损坏的机理着手,分析了过电压保护器应具备的条件,确定了较常用的带串联间隙四星形过电压保护器的选型、安装、定期试验方法及注意事项。认为,避雷器额定电压的选择应不小于9.94kV;避雷器持续运行电压的选择应大于最高运行线电压即7.2kV,并小于工频放电电压值;避雷器残压值的选择应低于15.9kV;工频放电电压的选择值根据负载不同,应在9.3kV～12.48kV。