Winter Soil Respiration from Different Vegetation Patches in the Yellow River Delta, China

Vegetation type and density exhibited a considerable patchy distribution at very local scales in the Yellow River Delta, due to the spatial variation of soil salinity and water scarcity. We proposed that soil respiration is affected by the spatial variations in vegetation type and soil chemical properties and tested this hypothesis in three different vegetation patches (Phragmites australis, Suaeda heteroptera and bare soil) in winter (from November 2010 to April 2011). At diurnal scale, soil respiration all displayed single-peak curves and asymmetric patterns in the three vegetation patches; At seasonal scale, soil respiration all declined steadily until February, and then increased to a peak in next April. But, the magnitude of soil respiration showed significant differences among the three sites. Mean soil respiration rates in winter were 0.60, 0.45 and 0.17 μmol CO(2) m(-2) s(-1) for the Phragmites australis, Suaeda heteroptera and bare soil, respectively. The combined effect of soil temperature and soil moisture accounted for 58-68 % of the seasonal variation of winter soil respiration. The mean soil respiration revealed positive and linear correlations with total N, total N and SOC storages at 0-20 cm depth, and plant biomass among the three sites. We conclude that the patchy distribution of plant biomass and soil chemical properties (total C, total N and SOC) may affect decomposition rate of soil organic matter in winter, thereby leading to spatial variations in soil respiration.     

节能环保型燃烧器技术特点分析及应用

由于原广泛使用的北美燃烧器存在技术落后、安全保护措施欠缺、操作复杂、安全隐患多、节能和环保不达标等问题,为适应当前注汽锅炉安全可靠、高效经济和低污染排放的运行要求,国内稠油热采注汽锅炉逐步应用新型节能燃烧器。通过总结各类新型节能燃烧器在燃烧效率、控制理念、动态监测、节能环保、燃料保护等方面的技术性能,分析其具有燃烧效率高、节能环保、安全可靠、自动控制水平高等特点,并验证实际运行效果,展望工业燃烧器技术发展趋势,为指导燃烧器选型和技术管理提供依据和参考。     

遗传投影寻踪回归在城市环境质量评价中的应用

引入投影降维的思想,将遗传投影寻踪与回归分析技术运用到城市环境质量评价中。将此技术与神经网络方法进行实例比较,投影寻踪回归方法不但可以合理地作出环境质量的综合评价,而且消除了神经网络方法中类别判断不够精确的影响。     

辉县市城区环境空气质量现状及污染防治对策

对辉县市城区2006—2011年间环境空气质量监测数据进行了评价,并对城区污染物浓度时空变化进行了分析。结果表明,辉县市城区大气污染主要表现为可吸入颗粒物污染严重,主要是能源结构不合理、锅炉废气污染严重、城区道路保洁方式落后等原因造成的,由此提出了合理规划城市布局、减少结构性污染等对策。     

Assessment of heterogeneity of metal composition of fine particulate matter collected from eight U.S. counties using principal component analysis

The main objectives of this study are to (1) characterize chemical constituents of particulate matter (PM) and (2) compare overall differences in PM collected from eight US. counties. This project was undertaken as a part of a larger research program conducted by the Johns Hopkins Particulate Matter Research Center (JHPMRC). The goal of the JHPMRC is to explore the relationship between health effects and exposure to ambient PM of differing composition. The JHPMRC collected weekly filter-based ambient fine particle samples from eight US. counties between January 2008 and January 2010. Each sampling effort consisted of a 5-6-week sampling period. Filters were analyzed for 25 metals using inductively coupled plasma mass spectrometry (ICP-MS). Overall compositional differences were ranked by principal component analysis (PCA). The results showed that weekly concentrations of each element varied 3-40 times between the eight counties. PCA showed that the first five principal components explained 85% of the total variance. The authors found significant overall compositional differences in PM as the average of standardized principal component scores differed between the counties. These findings demonstrate PCA is a useful tool to identify the differences in PM compositional mixtures by county. These differences will be helpful for epidemiological and toxicological studies to help explain why health risks associated with PM exposure are different in locations with similar mass concentrations of PM.     

椰壳活性炭吸附消除VOCs

对一种椰壳活性炭对甲基丙烯酸甲酯的吸附消除行为进行了研究,重点考察了甲基丙烯酸甲酯的浓度、流速和吸附温度等条件以及水汽存在时对活性炭吸附行为的影响。结果表明,该颗粒活性炭对甲基丙烯酸甲酯有良好的吸附效果,甲基丙烯酸甲酯进口浓度和进气量的改变均会影响吸附饱和时间,导致其增加或减少。通过变温吸附实验确定降低环境温度对其吸附有促进作用。湿度为50%时吸附量相对干气饱和吸附量影响较小,说明该活性炭抗水汽能力较好。经多次重复再生实验,其饱和吸附量未见明显下降。     

印染废水污染物在曝气生物滤池中的沿程去除规律

主要研究了曝气生物滤池（BAF）对印染废水中污染物的沿程去除规律。研究表明：BAF对印染废水污染物的去除沿高程有着不同的变化规律：在BAF总高度为300 cm,填料层高度为200 cm,气水比3∶1,停留时间11.8 h,的情况下, BAF对COD的去除主要集中在<160 cm的填料层部分,在总的去除率为63.1%时,此区域去除率可达56.60%;对NH3N的去除主要集中在填料层100～160 cm段,在总NH₃-N去除率为85.09%时,此区域NH₃-N去除率达38.28%。BAF对浊度的去除主要集中在填料层小于100 cm的部分,在总去除率为94.04%,区域去除率达到61.90%。印染废水经过BAF的前100 cm填料层后,pH值由10降至7.6后基本维持不变。     

复合型絮凝剂处理景观水体

利用以生物絮凝剂(1 g/L MBF-28)与化学絮凝剂(5 g/L PAC)复配后的复合絮凝剂CBF28C处理景观水体,考虑了复配比、投加量、pH和投加顺序对处理景观水的影响。实验结果表明:对于反应体系为100 mL景观水体,当MBF-28与PAC溶液复配体积比为3∶1,反应体系pH为7.0,1 mL 1%CaCl2作助凝剂,1.5 mL CBF28C时,其絮凝效果最好,其COD,色度,TN,TP的去除率分别为90.7%,54.1%、46.6%和51.5%。最佳水力条件为:快速320 r/min,快搅时间45 s,慢速80 r/min,慢搅时间100 s。并且得出了前10 min内絮凝率的反应关系方程式。     

滇池湖湾大水域种养水葫芦对水质的影响分析

为了探讨大水域种养水葫芦对滇池湖湾水质的影响,于2010年8—10月对滇池白山湾约70 hm2水葫芦种养区域的水质特征进行动态监测。结果表明,水葫芦区水体中总磷、总氮及高锰酸钾指数从9月中旬后开始逐步上升。水葫芦区水体溶解氧、pH较近水葫芦区和远水葫芦区显著降低,但水葫芦区溶解氧仍维持在较高水平;总磷、总氮及高锰酸钾指数较近水葫芦区和远水葫芦区显著升高;在水葫芦周围水体（近水葫芦区）水质得到明显改善,表现为水体透明度显著高于水葫芦区及远水葫芦区,总磷、正磷酸盐、总氮及叶绿素a明显低于水葫芦区及远水葫芦区。     

WRF-Chem simulation of East Asian air quality: Sensitivity to temporal and vertical emissions distributions

This study develops fine temporal (seasonal, day-of-week, diurnal) and vertical allocations of anthropogenic emissions for the TRACE-P inventory and evaluates their impacts on the East Asian air quality prediction using WRF-Chem simulations in July 2001 at 30-km grid spacing against available surface measurements from EANET and NEMCC. For NO₂ and SO₂, the diurnal and vertical redistributions of emissions play essential roles, while the day-of-week variation is less important. When all incorporated, WRF-Chem best simulates observations of surface NO₂ and SO₂ concentrations, while using the default emissions produces the worst result. The sensitivity is especially large over major cities and industrial areas, where surface NO₂ and SO₂ concentrations are reduced by respectively 3–7 and 6–12 ppbv when using the scaled emissions. The incorporation of all the three redistributions of emissions simulates surface O₃ concentrations higher by 4–8 ppbv at night and 2–4 ppbv in daytime over broad areas of northern, eastern and central China. To this sensitivity, the diurnal redistribution contributes more than the other two.