浅谈暖通空调工程中制冷系统管道设计及施工技术措施

暖通空调工程中的制冷管道是将制冷压缩机、冷凝器、节流阀和蒸发器等设备及阀门、仪表等连接成一个封闭循环的制冷系统,使制冷剂不间断循环流动,起到制冷作用。     

现代汽车故障诊断中数据流分析的应用与研究

通过对上海通用君威车型散热器冷却风扇电路原理的了解与分析,并结合对实车故障的排除,说明了数据流分析在汽车故障诊断的重要作用,应用数据流对现代汽车典型故障进行检测分析可以减少诊断时间,提高工作效率。     

滤棒储存输送柔性转弯装置的设计探讨

本文针对滤棒自动输送系统中滤棒储存输送装置中转弯半径过大,设计一种小转弯半径装置,及其工作原理和主要结构、应用场合的展望。     

中国航空货运顾客价值动因的实证研究

通过考察中国航空货运,建立航空顾客价值的决定因素与动态性理论模型,运用结构方程方法对其检验,结果表明:时间因素和便捷性因素是影响货运顾客价值的核心要素,价格因素已退之其次,而且来自竞争者、服务商、顾客、宏观环境的变化都对顾客价值动态性有显著影响。     

Does air pollution change a firm's business strategy for employing capital and labor?

We examine the impact of air pollution on a firm's capital-labor ratio. We propose the hypothesis that, in dealing with air pollution, a firm responds strategically by using relatively more capital and less labor to contain labor costs and remain competitive in the market. Using a sample of Chinese firms and a satellite-based air pollution metric, we test this hypothesis, and our results confirm it. In addition, we document that the impact of air pollution on the capital-labor ratio is more salient for firms with high economic incentives and close monitoring. Further, we report that to respond to worsening air pollution, a firm uses more capital and substitutes lower-quality labor with more high-quality labor. Finally, after increasing the capital-labor ratio, a firm's value increases, in terms of Tobin's Q, suggesting that the adoption of a higher capital-labor ratio, due to air pollution, is a sound business strategy.     

要想富，先修路？——不同交通运输发展在贫困地区经济发展效应的差异

基于中国11个集中连片贫困地区所涉及的87个地级市的动态面板数据,利用系统广义矩估计法克服内生性问题,可对不同交通运输方式在贫困地区的经济发展效应进行实证研究。研究发现,交通运输发展对贫困地区经济发展总体上起到了正向的促进作用,但不同交通运输方式在不同地区存在明显的差异。公路运输的发展在西南贫困地区和中部贫困地区的促进效果比在西北地区好。航空运输对中部贫困地区和西北贫困地区的经济发展同样起着显著的促进作用。普通铁路则因为在贫困地区的发展优势不明显,对经济发展的促进作用没有很好地发挥出来。     

Tradeable permits for pollution control when emission location matters: What have we learned?

Our knowledge about tradeable permit approaches to pollution control has grown rapidly in the two decades in which they have received serious analytical attention. Not only have the theoretical models become more focused and the empirical work more detailed, but we have now had over a decade of experience with them in the U.S. This article draws upon economic theory, empirical studies, and actual experience with implementation to summarize what we have learned about applying tradeable permits to air pollution control in the special circumstance where the spatial aspects of the problem are a prime consideration.     

Impacts of an EC carbon/energy tax and deregulating thermal power supply on CO2, SO2 and NOx emissions

Emission of CO₂, SO₂ and NO_x are all closely linked to the burning of fossil fuels. Here we report on simulations done by linking a Sectoral European Energy Model (SEEM), covering energy demand in nine Western European countries, with the emission-transport-deposition model RAINS developed by IIASA. The study analyses emissions of CO₂, SO₂ and NO_x, deposition of sulphur and nitrogen and the extent of areas where the critical load for sulphur is exceeded in year 2000 under four different energy scenarios. Two different sets of future behavioural patterns for the thermal electric power production sector are considered. In one regime, called the plan-efficient regime, the sector is assumed to follow official plans with regard to investment in new capacity. In the other regime, called the cost-efficient regime, the thermal power sector is assumed to behave in a cost minimizing manner. The effects of the proposed EC carbon/energy tax are studied under both regimes, giving rise to altogether four scenarios.In both regimes the effect of the EC tax is to reduce emissions by between 6 and 10 per cent in year 2000 relative to the scenarios without the tax. A change of regime, from the regulated, plan-efficient regime to the market-based, cost-efficient regime, will, by itself, reduce emissions of CO₂ and NO_x by approximately 3 per cent, while SO₂ emissions are reduced by 13 per cent. The EC tax will reduce sulphur deposition by more than 5 per cent in the nine model countries under the plan-efficient regime. A change of regime further reduces the total deposition by 9 per cent. The area where depositions exceed the critical load is reduced by approximately 6 per cent in year 2000 by the tax in both regimes. Changing from the plan-efficient to the cost-efficient regime has a similar impact.Although the emission reductions due to the EC tax may seem modest, they are shown to have a sizeable effect on the technological abatement costs of reaching targets like those prescribed in the Sofia protocol on the stabilisation of NO_x emissions, and the Helsinki protocol on SO₂ emission reductions. This is part of what can be considered to be secondary benefits of the EC carbon/energy tax.     

防空地下室建筑设计心得

通过对防空地下室发展趋势的了解,认识防空地下室的重要性;通过对防空地下室设计原则、功能形式、面积、防护单元划分、人防设备等方面的分析,简要说明防空地下室建筑设计中所包含的内容及应注意的事项。     

地下人防工程结构内力计算的特点

简要介绍了人防结构的设计特点,分析了关于等效静荷载的设计概念,并探讨几种人防结构构件上的荷载取值方法。