残余应力对局部轴压焊接圆柱壳承载力的影响

焊接钢圆柱薄壳广泛应用于钢筒仓和钢油罐结构中,屈曲通常是该结构的设计控制条件,圆柱薄壳的屈曲在大多数荷载工况下对焊接几何缺陷十分敏感.现有研究标明,焊接残余应力可少量提高均匀轴压圆柱壳的稳定承载力,但对于局部轴压荷载下圆柱薄壳中残余应力的效应,相关的研究很少.采用施加收缩应变法,建立了分别考虑焊接几何缺陷以及考虑或不考虑焊接残余应力焊接圆柱薄壳的数值分析模型,研究了含有周向焊缝、竖向焊缝以及砌砖式焊缝(patterned welds)的局部轴压焊接圆柱壳屈曲行为,通过比较考虑/不考虑残余应力圆柱薄壳的计算结果,得到残余应力对局部轴压圆柱壳承载力的影响.     

使用纤维素焊条的下向焊接技术

介绍了纤维素焊条的特点、焊条选型以及采用纤维素焊条焊接时对电焊机、焊接接头和焊接预热等的要求，提供了详细的纤维素焊条下向焊接的工艺参数，列举了施工实践中采用纤维素焊条焊接时经常出现的焊接缺陷类型，并对焊接缺陷进行了缺陷原因分析和制定了焊接缺陷预防纠正措施，为纤维素焊条的下向焊接施工提供了可靠的技术支持。     

Q550高强钢焊接箱形截面轴压构件局部稳定和相关稳定试验研究

针对Q550高强钢焊接箱形截面构件的局部稳定和相关稳定性能,对12个局部稳定试件和10个相关稳定试件进行轴压试验,对试件的初始几何缺陷和焊接残余应力分布进行测量。结合已有研究成果,提出一种焊接箱形截面残余应力分布模型,试验结果初步揭示了Q550高强钢焊接箱形截面轴压构件局部稳定和相关稳定的性能。     

变位器在摊铺机车架焊接上的研究应用

摊铺机车架是摊铺机上的主体结构件，车架存在体积大，重量重，焊接工序多，焊接角度变化大的特点，本文就车架采用大型变位器完成焊接工序进行研究，对于组成焊接变位器的提升机构、翻转机构、工装夹具、控制系统等部分进行了研究和分析。     

低温高湿度条件下16锰钢的焊接

通过分析16锰钢加工、焊接的特性，研究其在低温高湿度条件下产生焊接缺陷的影响因素，结合施工经验介绍了焊接缺陷的防止措施，以提高焊缝质量。     

20^#＋316L压合式非完全复合管焊接技术

20^# 316L压合式非完全复合管为压合式，但并非完全的复合，焊接质量要求高，焊接难度大。通过该项焊接技术在洛阳石化地下管网工程中的成功应用，重点介绍了该材料的结构、焊接工艺选择过程、焊接工艺的确定等。     

螺旋焊接方钢管混凝土轴压短柱性能

螺旋焊接方钢管短柱轴压试验，素混凝土短柱轴压试验，和螺旋焊接方钢管混凝土短柱试验等三组试验表明螺旋焊接方钢管混凝土轴压短柱的极限承栽力将大于螺旋焊接方钢管短柱和素混凝土短柱轴压承载力之和30％以上。通过将螺旋焊接的方钢管混凝土短柱轴压试验和直四缝方钢管混凝土短柱轴压试验结果的对比，发现前者的性能和后者相当，甚至更好。     

吊车梁上翼缘T型焊缝的焊接质量及其控制

根据生产实际，分析了吊车梁上翼缘T型焊缝焊接时容易产生的缺陷类型和原材料、焊接工艺、焊工等几方面对焊接缺陷形成的影响，提出了通过加强对原材料进厂复验和管理、焊接工艺控制、焊工培训等措施来提高焊接质量，实施结果证明，加强控制可大大提高吊车梁超声波探伤一交性合格率。     

船舶修造中焊接技术的应用前景分析

本文讨论了船舶焊接技术，探讨了船舶修造过程中焊接要求，以及在实际操作中焊接缺陷的原因及预防措施。     

Q690高强钢焊接箱形轴压构件整体稳定研究及设计建议

为研究Q690高强钢焊接箱形轴心受压构件的整体稳定性能,给出适合该类构件的设计建议,通过对3根Q690焊接箱形截面试件的残余应力试验,得到了箱形截面的残余应力分布模型。设计并制作了5根Q690焊接箱形柱,并对其两端铰支条件下进行了轴压试验研究,试验前分别对试件的几何初始缺陷和初始偏心均进行了测量。轴压试验中,所有试件破坏形式均为整体失稳破坏。基于试验结果,分析了该试件的整体稳定性能,采用直接分析法建立了数值模型,并校验了数值模型的准确性。同时,采用该数值模型对箱形轴压构件进行了参数分析,基于试验和参数分析结果,给出了Q690焊接箱形轴压构件的一阶弹性设计建议。     

Measurements of mercury in the near-surface layer of the atmosphere of the Russian Arctic

A series of measurements of gaseous elemental mercury concentrations in near-surface air of the Russian Arctic Region were carried out from 1994 to 1997. The measurements were conducted in Murmansk at a stationary site in April-May 1994, on a cruise in Motovsky Bay and Kola Bay during May-June 1996, and along the Russian Northern Sea Route in April-May 1997 on board the nuclear icebreaker 'Soviet Union'. Silver absorption was used for trapping of mercury and the mass of mercury was determined by cold vapour atomic absorption spectrophotometery. Detection limits were approximately 0.3 ng/m(3) (+/- error 46%). Sixty samples were selected and analysed. Sample volumes were 2.2 m(3) ashore, and up to 6.6 m(3) over water. The meteorological conditions, including a wind speed and direction, during the sampling period were typical of the spring-summer period of year, and therefore the concentrations of atmospheric mercury are regarded as representative for this season. The mean concentrations of mercury ranged from 2.2 ng/m(3) for Murmansk city, 1.7 ng/m(3) for Kola Bay, 1.6 ng/m(3) for Motovsky Bay, 1.1 ng/m(3) for the eastern part of the Barents Sea and 0.7 ng/m(3) for the western part of the Kara Sea. The levels of mercury in Murmansk, and over Kola and Motovsky Bays were associated with a primary direction of a near-surface wind from the nearest sources of mercury emission located in the Russian North region. These are the non-ferrous metallurgical plants in Nickel in the case of Motovsky Bay and Murmansk garbage-disposal plant, for sampling points in Murmansk and over Kola Bay. These concentrations of mercury, measured in the spring-summer season, in near-surface air of the Russian North, are more than two-fold lower than the concentrations that are typical of continental background regions in western Russia, and are comparable to the concentrations measured in the Arctic regions of other countries.     

On the simulation of the plume from stacks of buildings

A three-dimensional numerical model is used for a turbulent buoyant jet. The standard k–ϵ model has been modified to focus on the buoyancy-production term. The usual and modified buoyancy production coefficients are used for comparisons with experimental data reported in the literature. Imported numerical results are obtained with the modified coefficient for the stack–exit velocities and temperatures. The effects of these parameters on flow characteristics are discussed.     

工程机械整机系统可靠性的分析方法

概括分析了工程机械系统可靠性的数据处理方法，给出了建立可靠性计算模型的各种方法与步骤，并阐述了系统可靠性的分配方法和保证措施。     

Experimental Investigation of the Bearing Capacity of Piles Injected into Predrilled Holes in the Foundation Bed of the Odessa Opera and Ballet Theater

Results are presented for complex investigations of the strength and deformation properties of soils in the foundation bed of the Odessa Opera and Ballet Theater, which were conducted with plates and the testing of piles cast in predrilled holes. The procedure employed for the investigations is described. Piles injected into predrilled holes and their segments are tested to determine the friction along the lateral surface within the limits of bed sections that are, and are not prone to slump-type settlement. Actual compressive strengths are obtained for the bed soils along the lower surface of the piles, and also the resistance along the lateral surface.     

Educating Professionals for the Built Environment: the Challenge of the 1990s

For the built environment the challenge of the 1990s is already with us: for much of the decade the policies are in place, the plans are formulated, the landscapes are being developed, the buildings are designed, their interiors are sketched out and in many cases their construction has already started. All new student intakes will graduate in the 1990s. Infrastructure decisions are committing us well into the next century. So in many respects the educational challenge is to meet the forces of the new century, not the 1990s. These forces include internationalization of the economy, technological change, cultural diversification, restructuring of the property industry, changes to the professions, and a shake up in higher education both institutionally and pedagogically. In all these chal-lenges there is cause for optimism, but only if higher education can respond and in some areas lead these changes. This is especially true of professional education for the built environment.     

偏压基础直接解法的应用

以长宽比为设计控制参数,给出了柱下独立基础单、双向偏心受压及圆形基础偏心受压时基底尺寸的直接计算公式。可一次求得充分利用地基承载能力及经济合理的基础底面积。     

飞机库结构考虑多维输入影响的地震反应研究

对构造典型的大跨度飞机库采用反应谱法和时程分析法,考虑单向、双向和三向地震输入,计算对比结构各部位的地震反应,并进行这两种方法之间的比较。表明,对大跨度飞机库支承柱内力及柱顶位移,多维地震影响主要体现为水平次方向输入对主方向地震反应的影响。当主方向沿结构对称轴方向时,使柱沿主方向的内力及柱顶位移明显增大,而主方向沿非对称轴方向时这种影响较小;竖向地震对下部支承结构的影响可忽略;机库屋盖结构不同部位分别受水平和竖向地震控制,三向输入时地震内力比单独水平和竖向地震下均显著增大;采用时程分析时上述规律比反应谱法的结果更显著。据此给出了大跨度飞机库抗震设计计算的有关建议。     

试论电算化会计系统的内部控制

针对内部控制在企业中的重要性，介绍了计算机会计系统的开发、发展控制的主要内容，阐述了管理控制和日常控制的内客，以保证企业财产物资的重要性以及企业经济活动的正确性。     

Estimating shipping emissions in the region of the Sea of Marmara, Turkey

Ship emissions are significantly increasing globally and have remarkable impact on air quality on sea and land. These emissions contribute serious adverse health and environmental effects. Territorial waters, inland seas and ports are the regions most affected by ship emissions. As an inland sea the Sea of Marmara is an area that has too much ship traffic. Since the region of the Marmara is highly urbanized, emissions from ships affect human health and the overall environment. In this paper exhaust gas emissions from ships in the Sea of Marmara and the Turkish Straits are calculated by utilizing the data acquired in 2003. Main engine types, fuel types, operations types, navigation times and speeds of vessels are taken into consideration in the study. Total emissions from ships in the study area were estimated as 5,451,224 t y(-1) for CO(2), 111,039 t y(-1) for NO(x), 87,168 t y(-1) for SO(2), 20,281 t y(-1) for CO, 5801 t y(-1) for VOC, 4762 t y(-1) for PM. The shipping emissions in the region are equivalent to 11% of NO(x) 0.1% of CO and 0.12% of PM of the corresponding total emissions in Turkey. The shipping emissions in the area are 46% of NO(x), 25% of PM and 1.5% of CO of road traffic emissions in Turkey data between which and correspond to a higher level than aircraft emissions and rail emissions in Turkey.     

围岩量测技术在长岭隧道中的应用

以实际工程为例，系统地阐述了隧道工程中围岩量测技术的量测方法、注意事项、量测数据的处理以及围岩稳定性的判别方法；通过施工现场监测，探讨了围岩和支护在施工中的力学动态及稳定程度。