Die Wirkung der Dämpfe von Erdölbitumen auf Pflanzen1

The effect of vapours from asphaltic bitumen on plants . Asphaltic bitumen vapours escape from hot-mix asphalt plants and are deposited on leaves and shoots. Experiments were initiated to show whether such droplets cause injuries to plants. Results show that only certain sensitive plants develop symptoms, and then only when more than 3 mg of condensate are deposited per 100 cm² of leaf surface. Injuries caused by bitumen vapours and those caused by coal-tar vapours were closely related. They were both activated by UV-light and the symptoms were similar though milder in the case of bitumen. The differences are mainly due to the widely dissimilar content of aromatic hydrocarbons, the photoactivated agents common to the products.     

改性沥青砂应用于桥面防水层的施工

桥面防水粘结层的施工至关重要,其质量直接关系到整个桥面铺装防水粘结层的防水效果。本文介绍了改性沥青粘结层加铺改性沥青砂防水层的防水粘结层结构,针对SBS改性沥青砂桥面防水层的施工工艺展开探讨,为寒冷地区桥面铺装防水粘结层的施工质量控制提供参考。     

干拌法橡胶粉改性沥青混合料高温稳定性的时间敏感性分析

利用干拌法制作橡胶粉改性沥青混合料,将搅拌好的沥青混合热料在搅拌锅中进行闷料处理,温度恒温在165℃,分别闷至0 min、15 min、30 min、45 min、60 min,用每个时间段的沥青混合料制成试验用的试件进行高温稳定性分析,结果表明,在闷料开始阶段,橡胶粉改性沥青混合料的稳定度随闷料时间的增加逐渐提高,当闷料时间为15 min左右时,混合料的稳定性达到最大值,随后,稳定性逐渐下降。     

确定沥青再生剂最佳用量的试验研究

通过选择适当的原沥青，对其进行加速老化试验，测试其在不同老化时间下的针入度、延度、软化点，分析沥青的老化趋势。通过加入不同剂量的再生剂，分析再生剂对老化沥青的影响，确定再生剂的用量。最后确定出再生沥青混合料的再生剂用量。     

沥青混合料组成设计与马歇尔试验

马歇尔试验在沥青混合料配合比设计中起着重要的作用，无论是普通沥青混合料，还是SMA；但在其中所起的作用确实不同，在实际应用中需加倍注意。     

关于SBS改性沥青在旧路改造工程上的设计及施工

在良好的设计配合比和施工条件下,SBS沥青能使沥青路面的耐久性和高温稳定性明显提高。本文将根据施工试验情况,论述SBS改性沥青的施工技术要求。     

砂当量变化对微表处混合料性能的影响分析

细集料是组成沥青混合料的主要矿质材料之一，细集料的洁净程度直接关系到沥青与集料的裹附程度和粘聚力，显著影响沥青混合料的路用性能。通过室内实验，探讨砂当量变化对微表处混合料拌和时间和乳化沥青用量，以及成型后性能的影响。试验表明，砂当量高的集料可以减少乳化沥青用量，降低生产成本；施工时乳化剂品种的选择应以其用量对砂当量变化及拌和时间不敏感为原则；砂当量高的混合料成型后耐磨能力以及抗水损害能力明显提高。     

高等级公路沥青混凝土路面施工的几点体会

结合双鸭山双七二级公路改建工程第3合同段对沥青混凝土路面的施工过程，介绍了高等级公路沥青混凝土路面的配合比设计和施工方法，对今后的沥青混凝土路面施工有较好的借鉴作用。     

基于生态环境功能的透水性沥青路面设计研究

针对传统的非透水性路面的生态性缺陷,探讨透水性沥青路面在城市道路中的设计及应用。基于减小地表径流及蒸发降温等生态环境方面因素,设计透水性沥青混和料的目标空隙率及路面厚度;并对透水性沥青混和料的配合比设计进行研究,为透水性路面的设计及其推广应用提供借鉴。     

GLP型单组份异氰酸酯路用嵌缝胶的应用研究

水泥混凝土路面的嵌缝材料已由最初的沥青逐步发展为沥青玛蹄脂、聚氯乙烯胶泥等高分子胶结材料。但真正适用于寒冷地区白色路面的嵌缝材料却不多见。为此本文围绕以往白色路面嵌缝材料存在的不足 ,提出GLP型异氰酸酯嵌缝胶是一种适合材料 ,值得在工程上推广。     

Nutrient changes in potting mix and <Emphasis Type="Italic">Eucalyptus nitens</Emphasis> leaf tissue under macadamia biochar amendments

The effect of macadamia nut shell biochar on nitrogen, potassium, phosphorus, magnesium, calcium and sodium concentrations in potting mix used to grow Eucalyptus nitens seedlings was investigated in a glasshouse experiment. The treatments combined two fertiliser rates (50 and 100% rate of the commercial mix commonly used in forestry nurseries) with eight biochar rates (0, 2, 5, 10, 20, 50, 80 and 100 t ha^?1) arranged in a randomised complete block with three replicates of four sample plants. Nutrients were quantified in the potting mix and seedling leaves at four destructive harvests 135, 177, 219 and 269 days after planting. Biochar significantly increased nitrate-N, Colwell P, Colwell K and exchangeable Na and reduced ammonium-N, Mg and Ca concentrations in the potting mix. Seedling leaf concentrations of P, K and Na were increased by biochar application, while N remained dependent on fertiliser rate only. Mg and Ca leaf concentrations decreased in response to increasing biochar rates. Elevated nitrate-N and decreased ammonium-N concentrations suggest that biochar might have increased nitrification in the potting mix. We presumed that biochar mediated processes that reduced uptake of P and K when high doses of biochar were combined with full fertilisation. Changes in potting mix K, Na, Mg and Ca were consistent with selective adsorption of ions to biochar surfaces.     

沥青混合料配合比设计应注意的问题

热拌沥青混合料配合比组成设计是否合理,直接影响沥青砼路面的路用性能。本文对试验人员进行配合比设计时,如何规范操作和进行数据分析,减小试验数据的变异性以及优化沥青混合料配合比组成设计应注意的事项进行了论述。     

干拌法橡胶粉改性沥青混合料最佳沥青用量的研究

选取符合规范要求级配的石料做沥青混合料的原材料,用试算法确定混合料中各矿料质量百分含量为:机制砂石屑橡胶粉矿粉=56.0%34.0%2.5%7.5%。用干拌法拌制混合料,在拌制混合料时直接将废胶粉喷洒到处于搅拌状态的热沥青搅拌器中,制成胶粉改性沥青混合料。然后用马歇尔试验法确定出橡胶粉改性沥青混合料的最佳沥青用量为7.5%。     

混合像元分解研究综述

混合像元是遥感领域研究的热点,混合像元的问题若得不到很好的解决,将会给遥感的后续应用研究带来较大的误差.本文简要介绍目前国内混合像元的主要分解方法:有线性光谱混合模型、非线性光谱混合模型、模糊监督分类法和神经网络模型分类法,并对其优缺点进行了简要说明.     

Verschmutzung von Blatt- und Nadeloberflächen im Nahbereich einer Autobahn und deren Einfluß auf den stomatären Diffusionswiderstand

Pollution of leaf and needle surfaces near a highway and its effect on stomatal diffusive resistance. Young clones of several trees and shrubs were exposed on the dividing strip of a highway in spring 1976. After three months, surfaces of leaves and needles were extremely polluted and their stomata occluded. During warm dry days in June and July stomatal diffusive resistance in aspen, birch, alder and ash showed a significant (P<0.02) decrease compared to control plants. Compared with the control, temperature on the strip was higher in the soil but not in the air. It is suggested that this pollution effect may cause an increased water stress and reduced growth of plants in dry, hot periods.     

粉胶比对沥青混合料路用性能影响的试验研究

合理的粉胶比有利于提高沥青混合料的路用性能。试验在不同粉胶比条件下,通过车辙试验、低温弯曲试验、浸水马歇尔和冻融劈裂试验,分析沥青混合料的高温性能、低温性能和水稳性的变化,以确定合理的粉胶比范围。试验结果表明：粉胶比的增大,动稳定度增大,在粉胶比为1.2时出现峰值,随后开始下降;弯拉应变随粉胶比的增大而增大,粉胶比在1.0-1.1之间达到峰值,之后开始减小;劲度模量先减小后增大,呈凹形曲线,粉胶比为1.0时达到最小值;残留稳定度随粉胶比变化呈现增加后减小变化,最大值出现在粉胶比为1.0左右;冻融劈裂强度比先增大后减小,最大值在1.0-1.2范围内。综合考虑,在进行沥青混合料配合比设计时,粉胶比宜控制在0.9-1.2范围内。     

沥青砼路面平整度控制方法浅析

通过近几年在沥青面层施工工作中的实践 ,从沥青混合料的拌和、碾压、基层的平整度等方面分析了对沥青混凝土面层平整度的影响     

Aphidicidal activity of some indigenous plant extracts against bean aphid <Emphasis Type="Italic">Aphis </Emphasis><Emphasis Type="Italic">craccivora</Emphasis> Koch (Homoptera: Aphididae)

Aphidicidal activity of hot and cold water extracts of some indigenous plants, Azadirachta indica A. Juss (neem), Calotropis procera (Aiton) W.T. Aiton (akanda), Polygonum hydropiper L. (biskatali) and Ipomoea sepiaria J. Koenig ex Roxb. (bankalmi), were tested against the bean aphid, Aphis craccivora Koch. Hot water extract of P. hydropiper and A. indica was found to be the most effective (87.6–94.5 and 80.47–89.6% mortality respectively, P < 0.01) among all the extracts. Other hot and cold water extracts also appeared to be useful (59.5–87.5% mortality) as pesticides for A. craccivora. The highest yield (3.25 kg per plant) was obtained using hot water extract of P. hydropiper followed by hot water extract of A. indica (3.15 kg per plant). The lowest yield (0.32 kg per plant) was recorded from the control block. All the phytoproduct treatments had significantly (P < 0.01) better yield than the control block.     

Landscaping and performance of some aesthetic plant species in hot, arid conditions of India

Establishment of ornamental and aesthetic plants in hot, arid conditions of India is difficult due to the prevailing climatic, edaphic and biotic factors. Effect of turfgrass on the growth of ornamental plants in hot arid conditions has not been studied so far anywhere in the world. A study was conducted on the campus of Arid Forest Research Institute, Jodhpur, India to assess the performance of a few ornamental plant species in combination with turfgrass and without turfgrass with respect to different soil tilling intervals. Growth of plants was better with turfgrass than without turfgrass. We suggest adopting a soil tilling interval of 30 days to achieve optimum growth of ornamental plant species in terms of height and crown diameter. Our results can help reduce labor costs and achieving better landscapes in fewer days in hot urban conditions of Indian sub continent.     

Nutrient changes in potting mix and Eucalyptus nitens leaf tissue under macadamia biochar amendments

The effect of macadamia nut shell biochar on nitrogen,potassium,phosphorus,magnesium,calcium and sodium concentrations in potting mix used to grow Eucalyptus nitens seedlings was investigated in a glasshouse experiment.The treatments combined two fertiliser rates(50 and 100% rate of the commercial mix commonly used in forestry nurseries) with eight biochar rates(0,2,5,10,20,50,80 and 100 t ha~(-1)) arranged in a randomised complete block with three replicates of four sample plants.Nutrients were quantified in the potting mix and seedling leaves at four destructive harvests 135,177,219 and269 days after planting.Biochar significantly increased nitrate-N,Colwell P,Colwell K and exchangeable Na andreduced ammonium-N,Mg and Ca concentrations in the potting mix.Seedling leaf concentrations of P,K and Na were increased by biochar application,while N remained dependent on fertiliser rate only.Mg and Ca leaf concentrations decreased in response to increasing biochar rates.Elevated nitrate-N and decreased ammonium-N concentrations suggest that biochar might have increased nitrification in the potting mix.We presumed that biochar mediated processes that reduced uptake of P and K when high doses of biochar were combined with full fertilisation.Changes in potting mix K,Na,Mg and Ca were consistent with selective adsorption of ions to biochar surfaces.