Estimation of the recycled content of an existing construction project

The Government's Sustainable Buildings Task Group recently recommended a benchmark requirement for a minimum 10% of reused/reclaimed or recycled content (by material value) in construction projects. The benchmark would be implemented through Building Regulations and public sector procurement. This paper presents the findings of a pilot study to inform decision-making on the feasibility of setting and meeting such a requirement.The project involved determining current levels of recycled content in Defence Estates’ standard design for modern barracks accommodation, and quantifying the scope to increase this content. The existing designs for the new barracks were found to use nearly 20% recycled and recovered materials. The project identified opportunities to increase this proportion to nearly 25% with no increase in cost or risk.     

消化/剩余污泥水分扩散通量的研究

在传递理论的基础上,研究了干燥温度、污泥厚度及其种类3个主要因素对污泥水分扩散的影响,干燥温度设为30℃、40℃和50℃,污泥厚度设为1.3 cm、2.6 cm和3.9 cm,分别考察了消化和剩余两种污泥的干燥性能。利用实验数据获得两种污泥的有效质扩散系数,采用因次分析法建立了它们的水分扩散通量的准则关系式,通过实验研究两种污泥的水分扩散通量随干基含湿量的变化规律,并获得了两种污泥的水分扩散通量的经验公式。实验结果显示3.9 cm厚的消化污泥在40℃条件下的干燥效果最好。     

Physical properties of industrial wastes: laboratory tests

This article describes some laboratory tests performed on each kind of sludge located in an industrial wastes landfill. Measured physical properties are: field capacity, hydraulic permeability, saturation water content, effective porosity and particle-size distribution. The laboratory apparatus is described; the obtained results are analyzed to point out the possible correlations among the examined parameters. The aim of this work is to provide a data bank for industrial wastes landfills useful to perform some applications such as the evaluation of the produced leachate quantity for landfills whose wastes are similar to the ones here considered.     

铀、钍联合分析技术在水样分析中的应用

在简易实验室设备条件下,利用铀、钍联合分析方法——N135萃取分光光度法,测定了环境水样和高浓度放射性水样中放射性核素铀、钍的含量,并进行了方法比对和可重复性测试。结果表明,此方法准确性较高,具有良好的适用性。     

散煤运输用膜型抑尘剂的制备及性能研究

采用水溶液聚合法,以氧化淀粉、丙烯酸(AA)、二甲基二烯丙基氯化铵(DMDAAC)为原料,通过接枝共聚制备了一种软膜型抑尘剂(抑尘剂液体干燥后形成具有一定韧性的软膜)。与聚乙烯醇类壳型抑尘剂(干燥后形成很脆的壳层)相比,软膜型抑尘剂提高了煤粉固化层的抗破裂能力。由抗震荡性试验可知,使用膜型抑尘剂后,经过18 h的震荡,煤粉的损失率仅为1.91%,而使用壳型抑尘剂后煤粉的损失率为4.85%。还测定了2种抑尘剂的保湿性和耐破度。利用红外光谱对产物的结构进行了表征,采用SEM观察了该产物在煤粉表面形成的膜层形貌。试验结果表明,散煤运输中膜型抑尘剂在减少煤粉损失和控制扬尘污染方面性能优于壳型抑尘剂。     

Seasonal and interannual variation of soil respiration in four vegetation types in the loess hilly region北大核心CSCD

Soit carbon (C) stock is the largest C pool in terrestrial ecosystems, and the emission of CO2 through soil respiration contributes to the majority of soil C expenditure and atmospheric C. Soil respiration is also one of the major processes controlling the C budget of terrestrial ecosystems. A slight change in soil CO2 emission might cause drastic variations in global C balance. Therefore, it is of great significance to investigate the characteristics of soil respiration of soils growing different types of vegetation over a long period, and determine its relationship with variables such as soil temperature and moisture. The rate of soil respiration was measured each month in the growing seasons (from April to October) of 2011, 2013, and 2014 using the Li-8100 CO2 flux measurement system in the central Loess Plateau. Four types of vegetation (Quercus liaotungensis, Platycladus orientalis, Robinia pseudoacacia, and a natural shrub) were chosen for the periodical measurements. A permanent sample plot was established for each type of vegetation, and five polyvinyl chloride (PVC) collars were placed in each plot for the measurements. The temperature and water content of the soil in the upper 12 cm near the collar were measured using a digital soil temperature probe and a TDR 200 soil moisture meter at the same time when the soil respiration was measured. The soil respiration rates were fitted to the soil temperature and moisture with an exponential function, power function, linear function, and an equation combining the two variables. The results showed that: (1) the seasonal variation in the rates of soil respiration in the soils growing the four types of vegetation were almost the same, and were lower in the earlier period and then increased to high levels in the middle and later periods; (2) the rates of soil respiration in the same month varied with the type of vegetation grown, and were in the descending order: Q. liaotungensis > P. orientalis > shrub > R. pseudoacacia; (3) the average values of the rates of soil respiration in 2011, 2013, and 2014 were 2.77, 3.48, and 5.08 μmol m-2 s-1, respectively. The variation in soil respiration was higher across the three years than the variation for the types of vegetation grown; and (4) the rate of soil respiration was positively correlated to soil temperature and moisture for all the types of vegetation. A better fit was obtained by using the equation that included both the variables, soil temperature and moisture, than by an equation that included a single factor. Our results suggested that both seasonal and inter-annual variations of soil respiration occurred in the soils growing the four types of vegetation in the region. The temperature and water content of soils are the major regulating factors, and soil respiration in the Loess Plateau is more greatly affected by environment factors than by the type of vegetation. © 2018 Science Press. All rights reserved.     

基于典型学术期刊文献的资源科学研究态势探讨

论文采用文献计量学等研究方法,以CNKI近5 a的引文数据库数据为基础,对国内资源科学领域的26种典型期刊文献进行统计分析,得到国内资源科学领域Top 10的机构、期刊、主要基金资助及学科的分布状况,并对高频关键词进行了排序,得到目前排在前15位的研究内容。主要统计结果如下：排在前3位的机构是中国科学院地理科学与资源研究所、陕西师范大学和国土资源部信息中心;期刊包括自然资源学报、资源科学、中国人口·资源与环境等;主要的基金资助为国家自然科学基金、国家重点基础研究发展计划（“973”计划）、中国科学院知识创新工程基金等;排名前3位的领域有农业经济、环境科学与资源利用、宏观经济管理与可持续发展;研究内容主要是国土资源、地理信息系统（GIS）、气候变化、土地利用等。这些统计数据展现了目前资源科学的研究态势。     

焦化装置硫腐蚀危害及对策

针对茂名分公司因原料含硫量提高,致焦化装置的原料含硫量超过设计值,使设备腐蚀加重的情况,分析焦化装置原料含硫量的影响、危害及焦化装置的硫分布,对装置硫腐蚀机理进行了分析,并提出防止硫腐蚀危害的对策.     

The Effect of UV-B Irradiation on the Biodegradability of Poly-β-Hydroxybutyrate (PHB) and Poly-ɛ-Caprolactone (PCL)

The biodegradability of poly--hydroxybutyrate and poly--caprolactone in soil compostage before and after irradiation of the polymers for 192, 425, and 600 h in a Weather-Ometer was examined. The biodegradability tests were done in soil compostage at pH 7.0, 9.0, and 11.0 to assess the influence of this parameter on degradation. The rate of degradation was directly proportional to the soil alkalinity. Poly--hydroxybutyrate showed the greatest weight loss and aging in a Weather-Ometer did not significantly increase the biodegradation, except when the polymer was aged for 425 h and buried in soil compostage of pH 11.0.     

Biodegradation of Electrospun Poly-(ɛ-caprolactone) Non-woven Fabrics by Pure-Cultured Soil Filamentous Fungi

The biodegradation of electrospun nano-fibers of poly(-caprolactone) (PCL) was initially investigated with respect to the environmental application of PCL non-woven fabrics, using pure-cultured soil filamentous fungi, Aspergillus oryzae, Penicillium caseicolum, P. citrinum, Mucor sp., Rhizopus sp., Curvularia sp., and Cladosporium sp. Three kinds of non-woven PCL fabrics with different mean fiber diameters (330, 360, and 510 nm) were prepared by changing the viscosities of the pre-spun PCL solutions (150, 210, and 310 cPs, respectively). All of the pure-line soil filamentous fungi tested grew on the two fiber materials. Electron microscopy was used to observe the biodegradation processes revealing remarkable growth of two fungi, Rhizopus sp. and Mucor sp., along with the accompanying collapse of the nano-fiber matrices. In the biochemical oxygen demand (BOD) test, the biodegradation of the 330 nm PCL nano-fibers by Rhizopus sp. and Mucor sp. exceeded 20 and 30% carbon dioxide generation, respectively. The biodegradability of the PCL non-woven fabrics decreased with the mean fiber diameter and the 330 nm PCL nano-fiber that was made from 150 cPs solution (concentration, 7 wt%) exhibited the highest biodegradability. These results might offer some clues for the applications of the PCL non-woven fabrics having the controlled biodegradability in the environmental uses.