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131.
铝合金挤压型材广泛应用于建筑、包装、交通运输等方面,近年来在交通运输行业的应用呈上升之势。着重介绍了铝合金挤压型材的生产工艺、在汽车上的应用以及工业挤压型材的开发前景与技术难点。  相似文献   
132.
采用混凝-SBR生化-砂滤工艺,以超滤处理后的冷轧废水进行了处理。结果表明,CODcr为590 ̄1000mg/L的冷轧超滤废水经该工艺处理后,CODcr和BOD5的平均去除率分别为82.5%和94.3%,出水达到国家排放标准。  相似文献   
133.
The present study analyzed the impact of earlier rice phenology as a result of climate change on the risk of cold damage during reproductive growth using the historical temperature record from 1961 to 2010 at four locations in northern Japan. During this period, heading date has become 0.7-1.9 days earlier per 10 years. Air temperatures during the booting stage (6-15 days before heading) decreased by 0.18 °C per 10 years even though the air temperature on a given calendar date has increased slightly. The estimated potential yield losses caused by cold damage have increased since the start of the study period. Thus, the advance in phonological events as a result of global warming is likely to increase the risk of future yield losses, and this has important implications for future adaptation strategies (breeding new cultivars and changing crop management strategies) to reduce the risk of cold damage.  相似文献   
134.
Greg Bankoff 《Disasters》2019,43(2):221-239
A warming climate and less predictable weather patterns, as well as an expanding urban infrastructure susceptible to geophysical hazards, make the world an increasingly dangerous place, even for those living in high‐income countries. It is an opportune moment, therefore, from the vantage point of the second decade of the twenty‐first century, to review the terms and concepts that have been employed regularly over the past 50 years to assess risk and to measure people's exposure to such events in the light of the wider geopolitical context. In particular, it is useful to examine ‘vulnerability’, ‘resilience’, and ‘adaptation’, the principal theoretical concepts that, from an historical perspective, have dominated disaster studies since the end of the Second World War. In addition, it is valuable to enquire as to the extent to which such discourses were ideological products of their time, which sought to explain societies and their environments from the stance of competing conceptual frameworks.  相似文献   
135.
Extrusion coating experiments were carried out in the pilot line at Tampere University of Technology (Institute of Paper Converting). Commercially produced 3-hydroxybutyrate/3-hydroxyvalerate copolymer, commercial Finnish paper, and paperboard qualities were utilized as substrates. Functional properties, such as heat-sealing and hot-tack properties, pinhole density, and water vapor transmission rate were determined. PHB/V coatings exhibited approximately four–six times higher water vapor transmission rates (WVTR) than the corresponding LDPE coatings. The incorporation of wax or tall oil rosin into PHB/V improved its water vapor barrier. Curling of PHB/V was reduced by the addition of wax or tall oil rosin into the base polymer. PHB/V provided good heat-sealing characteristics at rather high sealing temperatures. Pinhole density was substantially reduced by using higher molecular weight PHB/V and by incorporating plasticizer into PHB/V.  相似文献   
136.
盐害(包括土壤次生盐渍化)造成的日益严重的环境问题已在世界范围内引起了广泛关注。大量针对植物耐盐分子机制的研究已开展,旨在更好地了解植物自身的耐盐机制。到目前为止,已获取了大量关于植物耐盐性机制的信息。同时,人们正在形成一个共识,即植物维持自身细胞离子平衡的能力是其具有耐盐性的关键。Na^+/H^+、K^+/H^+和Na^+/K^+逆向转运蛋白及其同源蛋自在植物细胞维持离子平衡中的关键作用受到了人们越来越多的关注。结合前人的研究结果和最新的研究动态,着重阐述了Na^+转运控制和维持细胞离子平衡在植物耐盐过程中的机理及其重要作用。  相似文献   
137.
盐害(包括土壤次生盐渍化)造成的日益严重的环境问题已在世界范围内引起了广泛关注。大量针对植物耐盐分子机制的研究已开展,旨在更好地了解植物自身的耐盐机制。到目前为止,已获取了大量关于植物耐盐性机制的信息。同时,人们正在形成一个共识,即植物维持自身细胞离子平衡的能力是其具有耐盐性的关键。Na+/H+、K+/H+和Na+/K+逆向转运蛋白及其同源蛋白在植物细胞维持离子平衡中的关键作用受到了人们越来越多的关注。结合前人的研究结果和最新的研究动态,着重阐述了Na+转运控制和维持细胞离子平衡在植物耐盐过程中的机理及其重要作用。  相似文献   
138.
利用苏州市2010—2012年大气污染物逐时质量浓度数据和气象条件资料,分析4类高影响天气对该市大气污染物扩散的影响。研究表明:暴雨对污染物的清除作用主要与降水时间和强度等因子有关,且降水时间的影响大于降水强度;夏季高温日污染物平均质量浓度高于非高温日,PM10、PM2.5、O3、NO2分别增长了29.5%、19.2%、51.3%和13.5%,且O3质量浓度大于321.6μg/m3的日最高气温均在33℃以上;寒潮过境对污染物有很好的清除效应,可对不同污染物影响程度不同;台风带来的大风和降雨能使污染物浓度迅速降低,其来临前的外围下沉气流可能对污染物浓度升高有影响。  相似文献   
139.
湿式消解法对冷原子吸收测定生物样品中汞产生的干扰   总被引:3,自引:0,他引:3  
用不同的湿式消解法对多种生物样品的进行消解测定,分析了实验的干扰因素,并推荐了比较适宜的消解方法。  相似文献   
140.
A novel and simple analytical procedure using cold activated carbon fiber-solid phase microextraction (CACF-SPME) was applied to determine organochlorine pesticides (OCs) in soil samples. The pesticides in this study consist of α -, β -, γ -, and δ -hexachlorocyclohexane (HCH). By heating the sample while cooling the fiber, the developed method not only provides better performance in terms of sensitivity, linearity and recovery but also offers shorter adsorption procedure than that of traditional headspace-solid phase microextraction (HS-SPME). The experimental conditions such as the amount of water, adsorption time and adsorption temperature were optimized. Matrix effects were investigated with different types of soils. We concluded that using the standard addition method was required for quantification purposes. The limits of detection obtained using the proposed method range from 0.01 to 0.05 ng/g, and the recoveries for CACF-SPME are in the range of 80.01% to 89.68% with relative standard deviation (RSDs) better than 8.60%. The proposed method was further applied to determine OCs in real agricultural soil. The results are in good agreement with those obtained using traditional ultrasonic extraction. The research demonstrates the suitability of the CACF-SPME for the analysis of OCs in soil.  相似文献   
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