砌体裂缝分析及其对策

结合砖混结构房屋的应用，对砌体结构的裂缝进行了分类，对裂缝的产生原因进行了分析；并针对性地阐述了砌体裂缝的处理措施，同时就砌体裂缝的预防进行了探讨，以解决砌体结构的裂缝问题，提高建筑物的质量。     

浅议砌体结构裂缝控制措施

在简要总结分析国内外砌体裂缝的性质和裂缝控制原则、措施的基础上，结合当前国情，针对性地提出了砌体结构裂缝控制的具体构造措施建议，以解决砌体结构的裂缝问题。     

浅议砌体结构裂缝的控制措施

分析了房屋建筑砌体裂缝的性质和裂缝控制措施。结合本地区的具体情况，针对性地提出了砌体结构裂缝控制的具体构造措施，以提高砌体结构的质量。     

砌体常见裂缝的分析与预防

砌体出现裂缝是非常普遍的质量事故之一。砌体轻微细小裂缝影响外观和使用功能，严重的裂缝影响砌体的承载力，甚至引起倒塌。在很多情况下裂缝的发生与发展往往是重大事故的先兆，对此必须认真分析，妥善处理。砌体中发生裂缝的原因主要有：地基不均匀沉降，地基不均匀冻胀，温度变化引起的伸缩，地震等灾害作用以及砌体本身承载力不足等五个方面。     

常见建筑砌体裂缝原因分析及防治措施

通过对常见建筑砌体裂缝的性质、原因及裂缝控制原则的分析，结合我国当前砌体结构的使用情况，针对性地提出了砌体结构裂缝控制的具体构造措施建议。     

浅谈砌体结构裂缝及防治措施

为适应市场经济、住房商品化的发展，针对砌体结构裂缝的问题，结合当前实际情况，借鉴国外成熟经验，简要分析砌体结构的裂缝原因，总结出砌体结构裂缝控制的具体构造措施。     

控制砌体结构裂缝的措施

本文根据砌体结构裂缝的性质结合我国国情，针对性地提出了控制砌体结构裂缝的措施，并根据西安某工程的具体应用，给出控制砌体结构裂缝措施的建议。     

关于砌体结构裂缝控制措施的建议

在简要总结分析了施工砌体裂缝的性质、裂缝控制原则和措施的基础上，针对性地提出了砌体结构裂缝控制的具体构造措施，从而保证整个砌体结构的质量。     

建筑砖砌体裂缝原因及其防治

建筑施工中常常使用建筑砖砌体，因此必须重视砖砌体施工过程中的避免性预见因素。砖砌体裂缝就是其中之一。其种类繁多，形态多样，普遍见于一般建筑中。砖砌体裂缝的出现不仅严重影响建筑物的美观，还会造成渗水漏水，影响建筑物稳定性。本文就砖砌体裂缝的主要类型和成因做了介绍，并提出了相应的预防对策。     

如何从设计上控制砌体结构墙体裂缝

论述了砌体结构墙体裂缝存在的危害性，探讨了墙体裂缝产生的原因，结合砌体裂缝的控制标准，从控制地基的不均匀沉降及温度和干缩裂缝两方面，提出了墙体裂缝的控制措施。     

Critical review of mercury fates and contamination in the arctic tundra ecosystem

Mercury (Hg) contamination in tundra region has raised substantial concerns, especially since the first report of atmospheric mercury depletion events (AMDEs) in the Polar Regions. During the past decade, steady progress has been made in the research of Hg cycling in the Polar Regions. This has generated a unique opportunity to survey the whole Arctic in respect to Hg issue and to find out new discoveries. However, there are still considerable knowledge gaps and debates on the fate of Hg in the Arctic and Antarctica, especially regarding the importance and significance of AMDEs vs. net Hg loadings and other processes that burden Hg in the Arctic. Some studies argued that climate warming since the last century has exerted profound effects on the limnology of High Arctic lakes, including substantial increases in autochthonous primary productivity which increased in sedimentary Hg, whereas some others pointed out the importance of the formation and postdeposition crystallographic history of the snow and ice crystals in determining the fate and concentration of mercury in the cryosphere in addition to AMDEs. Is mercury re-emitted back to the atmosphere after AMDEs? Is Hg methylation effective in the Arctic tundra? Where the sources of MeHg are? What is its fate? Is this stimulated by human made? This paper presents a critical review about the fate of Hg in the Arctic tundra, such as pathways and process of Hg delivery into the Arctic ecosystem; Hg concentrations in freshwater and marine ecosystems; Hg concentrations in terrestrial biota; trophic transfer of Hg and bioaccumulation of Hg through food chain. This critical review of mercury fates and contamination in the Arctic tundra ecosystem is assessing the impacts and potential risks of Hg contamination on the health of Arctic people and the global northern environment by highlighting and “perspectiving” the various mercury processes and concentrations found in the Arctic tundra.     

氡在破碎花岗岩巷道及围岩中的运移机制解析

依托某破碎花岗岩巷道工程,以多孔介质中气体的渗流理论为基础,综合考虑影响氡在破碎花岗岩山体及巷道中运移和析出的多种因素,构建了氡的数值计算模型,给出了山体和通风巷道中的氡浓度计算公式,模拟并比较了自然状态和微正压通风状态下山体中氡浓度分布的变化情况,并对微正压通风状态下巷道中氡浓度的变化情况进行模拟和验证。研究结果表明:扩散作用和渗流作用是巷道围岩中氡运移的主要机制;微正压通风条件下巷道中氡的运移主要受通风作用、围岩的射气作用和氡的衰变作用共同影响;微正压通风能够改变围岩中氡的渗流方向,是巷道降氡的有效手段。     

The effects of changing water flow velocity on the formation of biofilms and water quality in pilot distribution system consisting of copper or polyethylene pipes

We studied the effects of flow velocity on the formation of biofilms and the concentration of bacteria in water in copper and plastic (polyethylene, PE) pipes. The formation of biofilms increased with the flow velocity of water. The increase in microbial numbers and contents of ATP was clearer in the PE pipes than in the copper pipes. This was also seen as increased consumption of microbial nutrients in the pipeline system. This indicates that the mass transfer of nutrients is in major role in the growth of biofilms. However, the increased biomass of biofilms did not affect microbial numbers in the water. Rapid changes in water flow rate resuspended biofilms and sediments which increased the concentrations of bacteria and copper in water. The disturbance caused by the changing water flow was also seen as an increase in the particle counts and water turbidity recorded with online instrumentation.     

Cell phones for the spirits: ancestor worship and ritual economies in vietnam and its diasporas

Religion has been thriving in the Socialist Republic of Vietnam since ??i m?i, the onset of market reforms in the late 1980s. Votive paper offerings, part of spiritual and economic well-being, play a crucial role in performing religious practices in the socialist country as well as among diasporic Vietnamese. In urban Hanoi, material objects made from paper are traded in marketplaces and later burned in the streets, in temples and pagodas, in private yards and other places on special occasions in order to be transmitted to the ancestors. In the past few years, the range of votive paper offerings produced, traded, and sent to the deceased has expanded to include new forms and references to new media. Drawing on recent debates in the role of media in religion and in particular on technologies of mediation, I focus on the use of votive paper offerings in the sociocultural context of the Vietnamese spirit world. I explore how new media and media technologies are embedded in multilayered processes of mediation in Vietnam and its diasporas. Taking religious practices of burning votive paper offerings as an ethnographic example, this essay aims to contribute to ongoing debates on popular religion and the sacred life of material goods in late socialist Vietnam, on its transnational ties, and on the entanglements between religion, media and materiality.     

Towards an ‘Integration Model’ of Planning Education Programmes in a European and International Context: The Contribution of Recent Greek Experience

The article investigates planning education programmes and attempts to re-orient them in the context of both an international ‘problematique’ in reforming planning education, and European Union directives about the creation of a common European space in higher education. First, the article reviews the international trends in changes and challenges in planning and planning education in the 21st century and proposes an ‘integration model’ of planning education programmes in a European and international context. Second, the article focuses on the development of planning studies in Greece. It presents their history and development as well as the institutional framework in which planning and planning education operate. It then analyses the Greek educational curricula in two ways: (1) a quantitative analysis classifying courses into different thematic areas and thereby, revealing the basic structure of the curricula; and (2) a qualitative analysis based on interviews with academic staff in charge of educational curricula and examining the content of courses, the adopted pedagogies and possible restrictions (e.g. human capital, institutional framework, etc.) in introducing effective planning curricula. Finally, the article proposes guidelines for re-orienting educational curricula in Greek schools of planning and draws out wider implications for planning studies in the wider European and international context.     

The burning question: does burning before flooding lower methyl mercury production and bioaccumulation?

Production of methyl mercury (MeHg) is elevated in new hydroelectric reservoirs because organic carbon stimulates methylation of inorganic mercury (Hg) stored in the terrestrial system. This can cause adverse health in fish and in organisms that eat fish. We expected that burning vegetation before flooding would decrease the amount of Hg and organic carbon and thereby lower MeHg production. We conducted a replicated field experiment to investigate the effects of burning vegetation and soil before flooding on MeHg production and bioaccumulation. Vegetation and soil were added to mesocosms in the following combinations: unburned vegetation and unburned soil (Fresh treatments), burned vegetation and unburned soil (Partial Burn treatments), and burned vegetation and burned soil (Complete Burn treatments). Controls had no added vegetation or soil. During combustion with propane torches, a large percentage of the total Hg (THg) and MeHg was lost from vegetation and soil. THg and MeHg concentrations were highest in the surface water of Fresh treatments, lower in Partial Burn treatments and lowest in Complete Burn treatments and controls. Differences in concentrations of MeHg in biota were consistent among treatments, but did not follow aqueous concentrations. On the final sample date, MeHg concentrations in biota of Controls and Partial Burn treatments were greater than in Complete Burn and Fresh treatments. The lack of relationship between MeHg in biota and MeHg in water may have been due to modification of the bioavailability of MeHg by dissolved organic matter as the ratios of MeHg in biota to water were inversely correlated with concentrations of dissolved organic carbon. Although burning before flooding decreased MeHg concentrations in the water, it did not lower MeHg accumulation in the lower food web.     

The contribution of polyphenols to plant resistance to Pb soil pollution

This article considers the concentration of lead, polyphenols and water-soluble antioxidants (AOA) in the leaves of 4 species of woody, 11 species of shrub and 7 species of herbaceous plants growing in different functional zones in the city of Kaliningrad. The accumulations of Pb – the principal pollutant in urban ecosystems – were studied in the urban topsoil and plant leaves. An increase in Pb concentration in soils was associated with a decrease in AOA in tissues of the species examined. Changes in the background concentrations of antioxidants make it possible to estimate plant resistance to environmental stresses. The authors examine the contribution of polyphenols to the antioxidant potential of urban plants in soil polluted by Pb. The results obtained can be used to determine urban plant resistance to human impact and to improve the monitoring of industrial pollution in urban areas.     

Pools and fluxes of mercury and methylmercury in two forested catchments in Germany

Mercury (Hg) and methylmercury (CH3Hg+) are global pollutants, but little information is available on rates of atmospheric input, distribution and mobility in soils and catchments of central Europe. The objectives of this study were to investigate input and output fluxes of these compounds in a deciduous and a coniferous catchment in NE Bavaria (Germany), and to estimate pools and mobility of total Hg (Hgtot) and CH3Hg+ at the catchment scale. Bulk precipitation, throughfall, litterfall and runoff were collected biweekly from April 1998 to April 1999. Several soil profiles were sampled to estimate pools of Hg compounds in the catchments. In both catchments highest contents of Hgtot were found in the Oa layer of the forest floor (up to 500 ng g(-1)) and the soil storage of Hgtot calculated for a soil depth of 60 cm was approximately 890 g ha(-1) in the coniferous and 190 g ha(-1) in the deciduous catchment. Highest contents of CH3Hg+ in upland soils were observed in the Oi layer of the forest floor, and soil storage of CH3Hg+ was 4.35 g ha(-1) in the coniferous and 0.59 g ha(-1) in the deciduous catchment. The annual total deposition of Hgtot (total deposition not measured directly but calculated from throughfall and litterfall) was 541 mg ha(-1) year(-1) in the coniferous and 618 mg ha(-1) year(-1) in the deciduous catchment. Total deposition rates of CH3Hg+ were 3.5 and 2.6 mg ha(-1) year(-1). The contribution of litterfall to the total deposition of Hgtot and CH3Hg+ was 55% in the deciduous catchment. In the coniferous catchment, the contribution of litterfall to total deposition was only 29% for Hgtot, but 55% for CH3Hg+. By far the largest proportion of the deposited CH3Hg+ and Hgtot remained in the catchments (85% in the coniferous, 95% in the deciduous). As compared to remote Swedish catchments, deposition and output via runoff of Hgtot, were higher, but deposition and output of CH3Hg+ were lower in our catchments. In contrast to other studies, the annual budget revealed no differences in the mobility between the two species at the catchment scale. However, temporal patterns of the runoff fluxes and converse gradients of CH3Hg+ and Hgtot contents in the forest floor indicated differences in mobility on shorter time scales.     

关于中国REITs负债杠杆政策的研究

中国房地产业与金融业的结合越来越紧密,如何在中国发展REITs也备受关注。本文将对在中国发展REITs的负债政策进行研究。通过参考美国多年来REITs的负债水平及亚洲各国家和地区的负债政策,对中国在发展REITs起步阶段进行负债限制的必要性及合理的杠杆上限展开详细的实证研究。     

城外造景：清末广州景园营造与岭南 园林的近代转型

清末广州中西交汇,景园营造新旧共存互动,推 动岭南园林的近代转型。其中,在繁荣的中西贸易和文化交 流,以及书院文化、士绅文化等的影响下,清末岭南形成了 以广州为中心、十三行行商为代表、官商士绅竞相造园的特 殊历史时期,其造园数量、规模、意匠等均在该时期达到岭 南古典园林发展的巅峰。这一时期也是岭南园林近代转型的 关键时期。在西方文化和清末洋务运动思想的影响下,广州 开始出现洋务花园、公园、市政绿化,以及校园绿地等新型 园林形式。这些具有公共性质的城市景致与新建私园一道广 泛分布在城墙以外,成为清末广州城市空间拓展与风景体系 形成的重要参与者。由于清末广州城外造景的繁荣,从时间 上开启了岭南园林的近代转型,在空间上使岭南园林的地域 性特征得以形成和辨识,其空间性与时间性界定了清末岭南 园林近代转型的物质及文化维度。梳理了清末广州具有代表 性的景园营造活动,在分析其动力机制的同时,探讨城外造 景之于岭南园林近代转型的意义。