Emission factors of gaseous carbonaceous species from residential combustion of coal and crop residue briquettes

Experiments were performed to measure the emission factors (EFs) of gaseous carbonaceous species, such as CO₂, CO, CH₄, and non-methane volatile organic compounds (NMVOCs), from the combustion of five types of coal of varying organic maturity and two types of biomass briquettes under residential burning conditions. Samples were collected in stainless steel canisters and 2,4-dinitrophenylhydrazine (DNPH) cartridges and were analyzed by GC-FID/MS and HPLC, respectively. The EFs from crop residue briquette burning were generally higher than those from coals, with the exception of CO₂. The dominant NMVOC species identified in coal smoke were carbonyls (41.7%), followed by C2 unsaturated hydrocarbons (29.1%) and aromatics (12.1%), while C2 unsaturated hydrocarbons were the dominant species (68.9%) emitted from the combustion of crop residue briquettes, followed by aromatics (14.4%). A comparison of burning normal crop residues in stoves and the open field indicated that briquettes emitted a larger proportion of ethene and acetylene. Both combustion efficiency and coal organic maturity had a significant impact on NMVOC EFs from burning coal: NMVOC emissions increased with increasing coal organic maturity but decreased as the combustion efficiency improved. Emissions from the combustion of crop residue briquettes from stoves occurred mainly during the smoldering process, with low combustion efficiency. Therefore, an improved stove design to allow higher combustion efficiency would be beneficial for reducing emissions of carbonaceous air pollutants.     

污染土壤添加有机物质对黑麦草吸收铜的影响

研究了泥炭和堆肥对铜污染土壤盆栽黑麦草吸收铜状况的影响。结果表明 ,黑麦草地上、地下部含铜量皆随土壤污染水平提高而增加 ,地下部的增幅远大于地上部 ;添加有机物质明显降低了黑麦草地上、地下部的含铜量 ,平均降幅近 3 0 %。泥炭降低黑麦草地上、地下部含铜量的作用随土壤污染水平的提高而逐渐变小 ,而堆肥的作用至重度污染水平仍较明显 ;在近 4 0 0mg/kg铜污染水平上 ,有机物质表现出最佳降低植株铜吸收量的效果。有机物质的控制作用与土壤pH有关 ,并在 3茬黑麦草的试验期间内得以维持     

杀虫单降解菌的筛选分离与降解特性研究

从农药厂废水排放沟污泥中分离到一株对杀虫单有较强降解能力的菌株LY－4,经鉴定为巨大芽孢杆菌（Bacillus megaterium)。其生长的最适pH为7,最适温度为30℃。该菌对杀虫单有很强的耐受性,在杀虫单浓度ρ＝5000mg/L时,仍能较好地生长并发挥降解作用。当杀虫单初始浓度高于一定值时,一定量的菌剂对杀虫单的降解率随底物浓度的提高而降低,而绝对去除量则随底物浓度的提高而提高。与不加菌的对照相比,加入LY－4后,可使杀虫单浓度在很短的时间内降到很低的水平。图5表1参6     

微卫星位点TUT1的性别连锁检验(英文)

微卫星位点TUT1曾被认为位于松鸡科鸟类的常染色体上,只是多态性低于期望值,然而最近发现存在空基因现象.通过在45只斑尾榛鸡(Tetrastes sewerzowi)亲本和5巢双亲已知的幼鸟上扩增,发现TUT1在异配体的雌性中为纯合体,在84%的雄性中为杂合体,而且可从父本遗传给雌性和雄性后代,但从母本只能遗传给雄性后代.通过BLAST查询,含TUT1位点的序列(460 bp)与鸡Z染色体的序列最相似,分值329,期望值8e-87.以上结果表明TUT1位点位于松鸡科鸟类的Z染色体上;提示微卫星位点的空基因现象可能来自性别连锁,因此,在发表和应用微卫星位点时应当进行性别连锁检验.表1参17     

手性氟虫腈对意大利蜜蜂和稻螟赤眼蜂的急性毒性及安全评价

手性农药多以外消旋体形式用于农业生产和卫生害虫防治中。但手性农药对映体通常具有不同的生物活性和毒性,这种现象在农药环境风险评价过程中往往被忽视。本研究以氟虫腈为例,首先用高效液相色谱-手性固定相(HPLC-CSP)技术拆分出氟虫腈的S型和R型2种对映体,分别采用点滴法和药膜法测定了氟虫腈对映体及外消旋体对意大利蜜蜂(Apis mellifera L.)和稻螟赤眼蜂(Trichogramma japonicum Ashmead)的急性毒性。结果显示,S(+)-氟虫腈、R(-)-氟虫腈和外消旋体对意大利蜜蜂的48h-LD50分别为0.00341、0.00396和0.00383μg·蜂-1,对稻螟赤眼蜂的24h-LR50分别为7.56×10-7、8.06×10-7和7.29×10-7mg·cm-2。研究表明,氟虫腈对意大利蜜蜂具有高毒性风险,对稻螟赤眼蜂有极高毒性风险,且氟虫腈对意大利蜜蜂和稻螟赤眼蜂的急性毒性无明显的对映体选择性。因此,使用氟虫腈单一对映体不会降低其对环境生物的毒害风险。     

城市环境铂族金属分布特性及生态健康风险研究进展

随着铂族金属铂（Pt）、钯（Pd）、铑（Rh）被广泛应用于汽车尾气催化净化器中,这三种金属在自然界中的含量逐渐升高。越来越多的研究表明,这几种曾被认为对环境影响较小的金属的确会带来潜在的生态健康风险。本文概括了国内外城市各种环境介质的含量分布,重点分析了铂族金属的源解析方法、粒径分布特性、影响其排放的因素和其潜在的生态健康风险。就全世界的城市来看,灰尘、空气、土壤、沉积物等各种环境介质中铂族金属的含量均有显著提高,主要来源于汽车三元催化净化器。这三种金属倾向于富集在细颗粒中,行车模式是影响其排放量的重要因素,自然界的共存物质可增强它们的溶解性和迁移性,从而使它们的生物可利用性大大提高。生物体吸收这类金属后,可与体内的物质发生反应,形态发生变化,毒性增强。在以后的研究中,除了持续跟踪调查这三种金属在环境中的含量水平以外,还应加强研究这三种金属在环境中的颗粒分布、迁移转化、形态变换、生物可利用性以及生物毒性等,使我们能够更好地评估其生态健康风险,并为与之相关的应用研发、防范措施、政策制订提供引导和支持。     

武宁县森林扰动及驱动因子分析

森林扰动是影响陆地生态系统的重要因子,也是影响全球碳循环的重要因素.以江西省武宁县为例,利用1986-2011年14景Landsat TM/ETM+遥感影像,通过扰动指数(disturbance index,DI)时间序列轨迹分析提取森林扰动信息,并引入经验正交函数(empirical orthogonal function,EOF)分解方法定量分析了森林扰动的时空变化规律,利用GIS深入分析了自然和社会驱动因子影响.结果表明,武宁县森林扰动在1986-1998年较强,扰动面积以1992年为最大,以地区性扰动为主;2000年以后则趋于平缓,扰动以砍伐和森林火灾为主;在空间上,扰动主要发生在近道路、低海拔、低坡度和近水地区,并受地形和交通的制约,城镇化逐渐成为该地区森林扰动的一个不可忽略的驱动因子.     

Characteristics of fungal flora in onion farmlands with potential link to human mycotic keratitis

Acquisition of mycotic keratitis has been linked to agricultural activities. Although fungi were identified in injured eyes, data derived directly from farmlands are limited. Following five cases of fungal corneal ulcers in onion harvesters in the monsoon area of Taiwan, the present study further determined fungi genera and their concentrations in onion crops and surface soils of onion farmlands. In total, 52, 100 and 100 samples of soils, onion leaves and bulb scales, respectively, were collected from three monsoon and one non-monsoon farmlands. Fungal colonies were counted and microscopically examined after incubation at 25°C for 4–7 days on malt extract agar with 40?g?mL^?1 chloramphenicol. Results showed the peak fungi levels were mostly observed at harvest time. Among keratitis-related fungi, Aspergillus predominated in soils as well as in onion bulb scales, while Alternaria in onion leaves. Cladosporium was also prevalent in soils, onion leaves and scales. Other keratitis-related fungi included Acremonium, Curvalaria, Fusarium, Mycelia, Penicillium, Rhizoctonia and Rhizopus. The present study provides an exposure link between onion harvesters and presence of keratitis-related fungi from onion crops and soils, which may account for mycotic ocular infection via hand-to-eye contact and airborne transmission during the monsoon season.