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1.
In this study a method is suggested to compare the net carbon dioxide (CO2) emission from the construction of concrete- and wood-framed buildings. The method is then applied to two buildings in Sweden and Finland constructed with wood frames, compared with functionally equivalent buildings constructed with concrete frames. Carbon accounting includes: emissions due to fossil fuel use in the production of building materials; the replacement of fossil fuels by biomass residues from logging, wood processing, construction and demolition; carbon stock changes in forests and buildings; and cement process reactions. The results show that wood-framed construction requires less energy, and emits less CO2 to the atmosphere, than concrete-framed construction. The lifecycle emission difference between the wood- and concrete-framed buildings ranges from 30 to 130 kg C per m2 of floor area. Hence, a net reduction of CO2 emission can be obtained by increasing the proportion of wood-based building materials, relative to concrete materials. The benefits would be greatest if the biomass residues resulting from the production of the wood building materials were fully used in energy supply systems. The carbon mitigation efficiency, expressed in terms of biomass used per unit of reduced carbon emission, is considerably better if the wood is used to replace concrete building material than if the wood is used directly as biofuel.  相似文献   
2.
林洁 《交通环保》2004,25(5):29-30
主要介绍了广州港南沙护岸围堰及试挖工程陆域场地软基处理工程及其施工工艺对珠江口水质的影响,以及在施工过程中采取的一些预防措施。  相似文献   
3.
There has been growing concern over the build-up of greenhouse gase(GHGs) in the atmosphere, particularly carbon dioxide (CO2), as acause of global warming. The IPCC Third Assessment Report (2001) suggests two ways in which the choice of materials could berelevant. First, some materials, particularly wood, have the advantage thatthey continue to hold carbon (C)in their cells even after being convertedto products. The implications of this feature are well researched. Second,an area that is not well researched relates to the different energyrequirements for producing similar products made with different materials. Using the findings of recent research, this paper compares the energyrequirements and C emissions of manufacturing a product using wood withthat of other materials. The case study of utility poles demonstrates thepositive C and global warming consequences of the lower energyrequirements of wood in the U.S., compared to other materials such assteel or concrete. It demonstrates that GHG emissions associated withutility poles are a small but significant percent of total US annual emissions. Wood utility poles are associated with GHG emission reductions of 163Terragrams (Tg) of CO2 when compared with steel poles. This isabout 2.8 percent of US annual GHG emissions, which are estimated atabout 5.28 Petragrams (Pg) of CO2 annually. Thus, the use ofwooden utility poles rather than steel results in a small but significantreduction in total US emissions.  相似文献   
4.
介绍了新疆八一钢铁公司高炉烟煤的特点,指出了喷煤系统存在的缺陷,总结了高炉喷吹烟煤所采取的安全措施。  相似文献   
5.
Anthropogenic acid deposition causes forest soil acidification and perturbation of the soil forming processes. The impact of soil acidification on tree growth is discussed in view of the role of mycorrhizal fungi in weathering and nutrient uptake. A review has been carried out of experiments involving treatments of forest soil by lime and wood ash, where soil properties and soil solution composition have been investigated. Results from these experiments in Europe and North America are summarized. In general, the content of C in the mor layer decreased as a result of treatment due to higher microbial activity and soil respiration as well as increased leakage of DOC. In addition, the content of N in the mor layer, in general, decreased after treatment and there are occasional peaks of high NO3concentrations in soil solution. In nearly all reviewed investigations the pH of the deep mineral soil solution decreased and Al, SO4and NO3concentrations increased after treatment. These effects are probably due to the high ionic strength and increased microbial activity as a consequence of the treatments. In the soil, pH, CEC and base saturation increased in the upper horizons, but decreases in the upper mineral soil are also reported. In general, there was no increase in tree growth as a result of these treatments. The positive effects of the treatments on soil processes and tree growth are therefore questionable. In view of these conclusions, an investigation was carried out on the soil and soil solution chemistry and the role of mycorrhizal fungi in a spruce stand treated with two doses of lime and another treated with lime/ash in southern Sweden. The results of this investigation is reported in this volume.  相似文献   
6.
昆明-楚雄-大理-丽江地区地震软风险区划实例   总被引:1,自引:0,他引:1  
应用云南省昆明市、楚雄州、大理州、丽江市1900—2000年这100年内M≥5.0的地震记录资料,对该地区的地震灾害软风险区划进行了实例分析。结果表明,软风险区划图是以带有“层”结构的地图形式表述风险评估结果的,而“层”是根据可能性水平来划分的。因此,软风险区划图对分析结果的表述,不仅能对风险分析提供更多的信息,而且能提供风险值可信度的信息,从而使风险图“服务信息”丰富化。  相似文献   
7.
Java(Java也是美国加里福尼亚州Sun Microsystems公司的注册商标)正快速成为一种用于加工制造业和系统集成的计算机编程语言。相对于标准C和C^ 计算机语言而言,Java的多功能性和支持众多计算机操作系统和平台的显著特点,使它能在装备有不同计算机平台和控制系统的机械设备上使用提供了最大的方便性。从而提高了木材产品加工过程的安全性。本文就Java软件系统在木材加工和家具加工过程中的应用以及潜在问题进行探讨。  相似文献   
8.
延边地区公路沿线边坡失稳试验分析   总被引:2,自引:1,他引:2  
延边地区公路沿线分布着大量软岩,其岩性具有强膨胀性,致使这一地区公路边坡出现了多处滑坡现象。为了合理地处理这一工程地质问题,需要认真研究该种软岩的膨胀特性。选取滑坡体软岩为研究对象,定量分析了其自由膨胀率、无荷膨胀率和有荷膨胀率,并具体测定了其膨胀力,探讨了其膨胀率和膨胀力的变化规律,揭示了研究区软岩的膨胀特性,为公路建设中软岩边坡加固参数的选取提供了科学的依据。  相似文献   
9.
Habitat linkages can help maintain connectivity of animal populations in developed landscapes. However, the lack of empirical data on the width of lateral movements (i.e., the zigzagging of individuals as they move from one point to point another) makes determining the width of such linkages challenging. We used radiotracking data from wood frogs (Lithobates sylvaticus) and spotted salamanders (Ambystoma maculatum) in a managed forest in Maine (U.S.A.) to characterize movement patterns of populations and thus inform planning for the width of wildlife corridors. For each individual, we calculated the polar coordinates of all locations, estimated the vector sum of the polar coordinates, and measured the distance from each location to the vector sum. By fitting a Gaussian distribution over a histogram of these distances, we created a population‐level probability density function and estimated the 50th and 95th percentiles to determine the width of lateral movement as individuals progressed from the pond to upland habitat. For spotted salamanders 50% of lateral movements were ≤13 m wide and 95% of movements were ≤39 m wide. For wood frogs, 50% of lateral movements were ≤17 m wide and 95% of movements were ≤ 51 m wide. For both species, those individuals that traveled the farthest from the pond also displayed the greatest lateral movement. Our results serve as a foundation for spatially explicit conservation planning for pond‐breeding amphibians in areas undergoing development. Our technique can also be applied to movement data from other taxa to aid in designing habitat linkages. Caracterización de la Amplitud de Movimiento de Anfibios durante la Migración Pos‐Reproducción  相似文献   
10.
某木材加工企业安全评价中的危险因素辨识   总被引:1,自引:0,他引:1  
木材加工生产中危险有害因素较多,发生人员伤害事故的风险比较高. 用安全系统的理论和方法,以某木材加工企业生产过程为研究对象,通过危险有害因素辨识,对造成人员伤害的危险事件发生的可能性和导致伤害后果的严重程度进行了分析,为提出相应的安全对策措施提供了依据.  相似文献   
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