热虹吸管散热器与热管工质的实验研究

对以水、R11、丙酮、甲醇为热管工质的柱型热虹吸管散热器与以热水作为供热介质的常规散热器,从散热能力和表面温度的均匀性两方面进行了比较。探讨了热管工质的热物理性质及不凝性气体对热虹吸管散热器的影响,以丙酮、甲醇作为热管工质较为理想。实验散热器总放热量中,热对流放热量约占61％,辐射放热量约占39％。     

The development of epigeic fauna in new hedges — a comparison of spatial and temporal trends

The colonisation of a linear sequence of nine young hedge plantations (each 400 m²) within an intensely cultivated landscape about 30 km to the west of Bonn has been studied to compare spatial and temporal distribution patterns of epigeic arthropods in order to consider differences obtained concerning an assessment of colonisation characteristics and dispersal trends. The investigation was started in 1982, the year in which the new hedges were planted and continued until 1991. Pitfall traps—usually six as a standard set—were installed in young hedges and in old wooded habitats of an adjacent semi-natural habitat complex, as well as in surrounding arable fields and in meadow strips connecting the hedge plantations. But only in 1990 nearly all the habitats were sampled at the same time. Between 1982 and 1989 catches were continuously performed only in two habitats, since 1986 in four young habitats.Results on species of the taxonomical groups of Carabidae, Opilionida and Araneida show that the analysis of spatial only or temporal only patterns can lead to different interpretations and sometimes wrong conclusions about the colonisation of new hedge habitats. Both types of data, comprehensive spatial and long-term temporal, are complementary and a combination of both is recommended for properly assessing dispersal of species and other dynamic processes in the landscape. As far as the colonisation of new hedges is concerned it is shown that despite high temporal dynamics in species abundances and remarkable differences between the three taxa considered, the development towards a typical hedge fauna progresses very slowly. Small, 9-year-old hedges do not function well as stepping stones for the dispersal of epigeic forest and forest-edge arthropods, and only a small corridor effect could be established for the linear plantation strip. Remarkable differences in colonisation trends between beetle and spider species of similar ecological preferences are discussed.     

园林景观工程师的岗位职责和现代素养

园林景观工程师的工作水平直接决定了园林项目的管理水平。本文结合园林景观工程师工作实践,分析了园林景观工程师在园林工程和景观工程中的主要岗位职责和工作特点,以及在现代社会中所应具备服务、管理和专业方面的相关的素养,以期为园林工程师的队伍建设提供理论指导。     

Comparative ecological risks of pesticides used in plantation production of papaya: application of the SYNOPS indicator

Pesticides are used intensively for crop protection in tropical fruit plantations. Assessments of the relative risks posed by pesticides are needed to assist in the development of management plans that minimize ecological impacts. In this study, the risk indicator SYNOPS_2 was used to compare risks to aquatic ecosystems by pesticides commonly used in papaya plantations. Plant interception and spray drift were measured during six applications of three pesticides (chlorothalonil, chloropyrifos, and malathion) using a turbo fan driven sprayer. Plant interception was estimated to be higher (42.6+/-12.7%; p=0.04) in late (8-14 months old) than in early (4 months old) trees (20.1+/-25.3%). Chlorothalonil concentrations of up to 11.0 microg L(-1) were found in water from an adjacent ditch after field application. Concentrations of this pesticide (7.4+/-4.1 microg L(-1)) in runoff water were also significantly (p<0.01) higher than those of malathion (2.4+/-1.9 microg L(-1)) and chlorpyrifos (0.8+/-0.5 microg L(-1)). Good correlation between measured and predicted values (r2=0.56-0.85, p<0.01) showed that SYNOPS_2 is able to describe trends in runoff pollution in papaya plantations. Linear equations were obtained in order to correct numerical disagreement between measured and calculated runoff concentrations. An independent test showed a reasonable agreement between measured chlorothalonil concentrations and the predicted values using the proposed equations. Fifteen pesticides used in papaya cultivation were ranked according to their calculated chronic biological risk index. Pesticides with the highest risk index for non-target organisms were: chlorothalonil for algae, lambda cyahalotrin for Daphnia and fish, and malathion for earthworms. Chlorothalonil was the pesticide with the highest exposure level in water and therefore represents a high risk for aquatic life. Results show that SYNOPS_2 can be used as a pesticide risk indicator on papaya and possibly other tropical fruit plantations.     

The influence of forest management on landscape structure in the cool-temperate forest region of central Japan

Comprehension of historical changes in landscape and forest management will provide valuable insights into current ecosystems and biodiversity and will support future management decisions and conservation strategies. This study clarified changes in the forest landscape of the cool-temperate forest region of central Japan from 1947 to 1997. We used a geographic information system to reconstruct past forest landscapes at four times (1947, 1962, 1975, and 1997) based on interpretation of aerial photographs and landscape metrics calculated using the FRAGSTATS software for spatial pattern analysis. Our results showed that secondary forests, the dominant land use in 1947, decreased greatly in area and became more fragmented, whereas coniferous plantations, which occupied approximately 20% of the total land area in 1947, became the dominant land use (almost 40% of the total land) by 1997. The young coniferous plantations have been established at increasing elevations over time and were mainly created by conversion of secondary forest until 1975. The number of young coniferous plantations and their patch spacing depended on the type of forest management. In the study area, landscape structure changed in response to changes in management of national forests, especially the expansion of afforestation in the 1950s and 1960s and changes in harvesting systems.     

融科咨讯中心景观规划建设的启发

联想集团与美国SOM、SWA联手，打造联想科学园的项目，是一次成功的合作。其中景观规划先行、对场所精神的理解，对人的关怀等突出特点，有别于国内大多数景观作品，整个运作过程也颇具典型意义，对业内人士具有很大的启发性。     

To be an expatriate manager in Saudi Arabia is it that different?

Although much has been said in the media about the different lifestyle the expatriate will experience in the Saudi Kingdom, with its restrictions on alcohol consumption and dress for women, very little is said about the work environment. Here, the author examines whether there are other difficulties to working and living in Saudi Arabia, or whether it is all just media hype     

空调风量控制方法的综合性分析

空调设备的节能运行以及设备的初期投资和全寿命运行费用是用户、设计和施工单位均非常关心的问题。运用技术可行性、节能效果、设备初期投资以及全寿命成本综合分析的方法 ,对于多种空调风量控制方法进行了综合评判。空调风机的输出功率近似比例于其转速的立方 ,根据该负载特性 ,从调节范围、灵敏度、维护保养、可靠性等方面着重分析了基于晶闸管斩波技术的风机调速方案 ,分析认为在多种可供选择的节能运行方案中 ,该方案是廉价、高效、实效性强的空调风量控制和节能方案。针对某大厦进行了实例分析和对比 ,给出的分析算例支持了以上结论     

多媒体计算机辅助技术在土木工程领域的新进展

为了使计算机及相关学科的高新技术与土木工程学科和技术的发展相得益彰,综述了目前跨学科研究的前沿课题,在全面分析多媒体信息及其计算技术在我国土木工程领域中的应用研究发展现状和趋势的基础上,结合作者从事的研究课题,论述了MCAE的新概念,并就怎样创造具有广泛社会需求和经济效益的新成果提出了见解.     

秋冬季围护结构绿化对建筑保温性能的影响

制作两个相同的模拟实体建筑的混凝土模型,采用控制变量的方法,在一个模型的围护结构上布置100％覆盖率的屋顶绿化和50％覆盖率的墙体绿化作为实验模型,另一个不布置绿化作为对照模型,采集两个模型内外部的温度数据.计算分析表明,2010年10月～2011年3月间,实验模型的平均积温要比对照模型的高1.31,绿色植被能够有效降...     

复合土钉工作机理与变形控制分析

在论述土钉的基本概念与工作机理的基础上,介绍了复合土钉的一般形式及其适用条件,着重分析了复合土钉的工作机理;同时,以土钉与水泥土桩墙组合式复合土钉为例,研究讨论了复合土钉变形的影响因素以及设计阶段和施工中的变形控制措施,可供研究与工程参考。     

基于开挖影响线的隧道分部开挖拱顶沉降分析

隧道的开挖从力学上来说也是一种荷载,掌子面移动的过程可以看作是荷载移动的过程。借鉴结构力学中影响线的概念,定义隧道工程的“开挖影响线”为某一考察指标与掌子面位置的关系曲线。相比结构力学简支梁影响线,隧道工程开挖影响线的主要特征表现为影响范围是局部的,且呈非线性,考察指标的最大响应并非掌子面到达考察断面。基于依托工程的隧道拱顶沉降开挖影响线表明⑥部开挖引起的A点沉降最大,约占其总沉降的21.5%。开挖体量约占总开挖量40%的⑨⑩部开挖由于是在二衬的保护之下进行,其引起的A点沉降仅占总沉降的2.1%。从影响线形态可以看出影响A点沉降的开挖范围大部分集中在到达A点前5m和通过后15m,且以掌子面通过考察断面时影响最为剧烈。     

The Governance of Mandated Partnerships: The Case of Social Housing Procurement

Partnership working is nowadays a seemingly ubiquitous aspect of the management and delivery of public services, yet there remain major differences of opinion about how they best work for the different stakeholders they involve. The balances between mandate and trust, and between hard and soft power, are crucial to current debates about public service partnerships. This paper explores the example of social housing procurement in Northern Ireland, and the requirement to form mandated procurement groups. The research shows that the exercise of hierarchical power is still important in network governance; that mandated partnerships alter the balance between trust and power in partnership working, but the impact is uneven; and that these relationships are (re)shaping the ‘hybrid’ identity of housing associations. The balance between accountability for public resources and the independence of third sector organisations is the key tension in mandated partnerships. The Northern Ireland experience suggests that trust-based networks could provide more productive working relationships in partnerships for service delivery.     

摊铺机设计(一)

本文从实际应用出发，阐述了在摊铺机总体设计中应遵循的浮动摊铺工作原理及针对摊铺机的工作特点而研究的一些设计理论，并完整地介绍了行走、刮板、螺旋、振捣、振动、液压、电气等系统的设计方法和计算公式，同时还推荐了一些经验公式和设计参数。     

地铁车站拱盖法施工沉降监测分析及控制对策

青岛地铁3号线中山公园站位于土岩复合地层中,采用拱盖法施工,车站开挖最深约27.24 m,上层为第四系强风化花岗岩,下部为中微风化花岗岩、花岗斑岩。局部强风化厚度大,中、微风化岩面局部较陡峭,岩层接触部位易失稳。为使开挖工程顺利进行,对开挖过程地表沉降进行监测分析。结果表明:采用拱盖法施工时,导洞掌子面施工至监测断面前方20 m左右时开始出现沉降;随着掌子面与监测断面距离的减少,沉降速率不断增加;掌子面下穿监测断面时,一般沉降量为7～15 mm;穿过监测断面5～10 m时,监测点沉降速率达到最大;穿过监测断面10 m后,沉降速率开始下降;穿过监测断面20 m后,大部分监测点趋于稳定。为保证支护起到良好的控制地表沉降的作用,初期支护应在开挖后立即施作,并尽早闭合。此外,左、右导洞在开挖过程中会相互产生较大的沉降影响,监测发现左、右导洞开挖间距在2.5倍洞径左右为宜。通过监测分析,提出一系列控制对策,实践证明,这些措施是可行且有效的。     

注浆技术在新元矿回风立井中的应用

针对阳煤集团新元矿回风立井涌水事件,提出了工作面注浆施工方案,重点介绍了工作面预注浆及壁后注浆的施工工艺,所采用设备及相关技术参数、技术要求等,通过采用工作面预注浆及壁后注浆工艺,分别对即将穿越的含水层及井筒最终涌水量进行控制,取得了较好的防水效果。     

北京地区建筑农民工工作和生活状况调查

本文通过问卷调研和现场采访,在北京地区采集了与建筑农民工工作和生活状况相关的信息,共回收有效问卷931份.总结了农民工的年收入、工作经历、劳动合同、安全及饮食等基本情况,发现建筑农民工对工作的满意程度主要与其是否被拖欠工资、合同签订情况、年收入以及工作经历有关.本文还指出农民工对安全状况的满意程度主要与培训情况有关,并针对饮食条件说明了目前在一些工地存在的问题,最后提出了几点建议.     

下承式刚性系杆拱桥的结构温度效应研究

以桐庐富春江二桥60m跨度的拱桥为对象,根据桥位的温度实测数据分析下承式刚性系梁拱桥由于上、下部结构温度差产生的温度效应。通过与使用荷载、体系温度荷载及系梁温度梯度荷载的工况对比结果,表明上、下部结构温差产生的拱肋轴力为使用荷载的4倍左右,且拱肋的弯矩远大于使用荷载下的弯矩值,对拱肋的结构安全性验算有较大的影响,设计时须注意。     

深埋煤层开采的离心模型试验研究

 以菏泽井田赵楼煤矿近千米深埋煤层首采区地质条件为依据,通过离心试验研究采动影响下,煤层顶板不同位置的应力变化规律,结果表明：(1) 开切眼处煤柱处压力随煤层的采动不断变化,对其压力产生明显影响的是前方约35 m煤层的开采,最大应力集中系数为2.04;开挖工作面前方10～15 m煤层支承压力集中,最大应力集中系数为2.8。(2) 直接顶处岩层压力随煤层的采动不断变化,在工作面处达到峰值,最大应力集中系数为1.74,工作面推过后,其压力下降后又有所回升,为上覆岩层重新压实所致。(3) 老顶岩层压力亦随煤层开采不断变化,但其峰值出现在工作面推进后5～10 m,最大应力集中系数高达3.91,在煤层开采过程中,要加强观察和支护,预防冲击地压等灾害的发生。(4) 综合得出赵楼矿井老顶的初次断裂步距约为30 m。试验结果可为煤炭深部开采条件下的岩层控制、合理的巷道布置、改善巷道支护和维护情况及冲击地压的预防提供依据。     

道路综合养护车工作装置计算机仿真研究

本文依据道路养护作业要求,在运动分析的基础上,利用计算机在ＭＤＴ平台上完成了清沟、剪草、水泥路面破碎三种工作装置三维实体秸和动态仿真,并对其三种工作装置的运动轨迹进行了分析,绘制了作业范围图,用两种方法确保结果的准确性。