厦门酸雨的区域分布及降雨过程分析

测定了厦门市几个代表点1993年3月至7月间雨样的pH值,并用ICP－AES方法测定了S、Ca、Mg等元素的浓度,实验结果表明,各区域雨样的pH值不仅与致酸污染物的排放(主要表现在S元素浓度上)有关,而且受到该区域的地理条件的影响,体现出酸雨的形成是致酸因素与致碱因素互相平衡制约的结果的一般规律。根据单场雨的分段分析数据,总结出pH值随降雨过程变化的几种模式,并分析了其成因。      

武昌珞珈山酸雨监测研究

本文报导了自１９９１年１月－１２月及１９９４年１月－７月收集到的５９个珞珈山雨样进行监测的结果。结果表明每年的春季和冬季出现酸雨。酸雨是典型的由燃煤引起的硫酸型酸雨．酸雨的出现同该地区大气污染的状况相吻合。     

江油市降水pH值的时间分布特征及控制对策

根据江油市2001～2009年的监测资料,首次分析江油市降水PH值的状况和变化.在降水酸碱类型的频率分布统计特征的基础上,探讨江油市降水pH值的季节分布特征及夏季酸雨的成因,并提出控制措施.     

鹰潭市酸雨污染现状、趋势与成因分析

采用2001-2010年降水监测数据,全面系统地研究分析鹰潭市酸雨污染现状、变化规律,并从环境空气质量、区域污染物输送、气象因素和土壤性质等方面探讨酸雨形成的主要原因,得出区域输送是鹰潭市酸雨污染的主要因素。     

耐候ABS材料研究

通过自然气候老化和紫外老化试验UV-B,研究了ABS塑料外观颜色、力学性能在老化实验过程中的变化.试验结果表明:光稳定剂的加入,ABS耐候性能提高,相较未加光稳定剂ABS体系,AE值下降,冲击保持率提高,受阻胺光稳定剂A和紫外光吸收剂B、C并用有协同作用,光屏蔽剂的使用可以提高耐候性,从而降低成本.此外我们讨论了自然气...     

The Precision of Precipitation Chemistry Measurements in the Canadian Air and Precipitation Monitoring Network (CAPMoN)

Precision estimates are presented for precipitation chemistry and depth measurements made by the Canadian Air and Precipitation Monitoring Network (CAPMoN). The estimates were made for daily measurements of ion concentration and precipitation depth as well as for weekly, 28-day, seasonal and annual precipitation-weighted mean concentrations and depths. The data on which the estimates are based were collected from collocated samplers at five CAPMoN sites during the period 1985 to 1993. The data pairs from the collocated samplers were used to calculate the between-instrument error defined as 1/2 times the difference between the paired sample concentrations (or depths). For all of the ion concentrations and depths, the between-sampler errors were found not to be normally distributed, but the normality of the distributions improved with the length of the (volume-weighting) time period considered. A set of quantitative measures of overall network precision were derived in absolute (mg L^-1) and relative (%) units. These included the Modified Median Absolute Deviation (M.MAD), the P90% probability values and the Coefficient of Variation (CoV). The latter, defined as the percent ratio of the M.MAD to the median concentration (or depth), represents the relative precision at the center of the error and concentration (and depth) distributions. Based on the CoV values, the relative precision of the CAPMoN measurements was very high (better than 4%) for SO ₄ ^2- , NO ₃ ^- , pH, H⁺, NH ₄ ⁺ , sample depth and standard gauge depth, and not as high (between 10 and <35%) for Cl^-, Na⁺, Ca²⁺, Mg²⁺, and K⁺. The ions with the lowest median concentrations had the poorest relative precision since so many of the concentrations were at or near the analytical detection limit. Except for the sample and standard gauge depths, both the absolute and relative precision improved with the length of the precipitation-weighting period. Detailed statistical testing established that the precision of the daily measurements is dependent on a number of factors, the most dominant being sample depth and concentration, i.e., the absolute precision improves with increasing sample depth and decreasing concentration. The strength of these relationships diminished with the length of the precipitation-weighting period being considered. Laboratory-related sources of imprecision were found to account for less than 4% of the overall daily measurement imprecision for most species, while field-related sources of imprecision accounted for the balance. Specialized plots are shown which allow data users to estimate the absolute and relative precision at any concentration and depth value.     

合流制排水系统降雨径流污染物特征及初期冲刷效应

合流制排水系统降雨期间高污染溢流污水直接排入水体对水体质量有明显影响,其径流污染物输出特征和初期冲刷效应受排水区类型、面积、降雨特性等多种因素影响。为此,选取昆明市典型合流制排水系统明通河流域不同类型集水区进行降雨径流监测,研究合流制排水系统降雨径流污染物输出特征及初期冲刷效应。结果表明:合流制排水系统初期合流污水污染物质量浓度明显高于后期,不同污染物输出特征、形态差别较大,溶解态氮是N污染物的主要赋存形态,而P污染物主要以颗粒态形态存在。管道沉积物是合流污水重要的污染来源。年内次降雨污染物平均质量浓度以雨季初期降雨最高,中期降雨质量浓度最低,雨季后期质量浓度较中期略有上升。不同类型集水区N、P质量浓度排序为:居民区>城市综合型>综合型>城郊结合型。降雨量是影响初期冲刷效应的关键因素,雨量大的降雨初期冲刷效应明显。     

模拟酸雨淋溶条件下紫壤淋出液中溶解性有机质的三维荧光特性

运用三维荧光技术分析了模拟酸雨淋溶紫壤淋出液中溶解性有机质（dissolved organic matter,DOM）的组分与酸度及淋溶量的关系.研究结果表明,模拟酸雨淋溶紫壤淋出液中DOM荧光峰主要为类胡敏酸和类富里酸,荧光峰的中心位于Ex/Em=305—370 nm/420—450 nm和Ex/Em=260—270...     

模拟酸雨与重金属复合胁迫对绞股蓝生长及根际微生物的影响

通过盆栽试验研究了不同pH值的模拟酸雨与Zn(30和400 mg.kg-1)、Cd(1和15 mg.kg-1)单独或复合胁迫对绞股蓝(Gynostemma pentaphyllum)药用成分——总皂甙含量以及根际土壤微生物数量和组成的影响。结果表明:不同pH值的模拟酸雨均能抑制细菌、放线菌、氮素生理类群的生长,其数量随酸雨pH值的降低而不断减少;真菌、纤维素分解菌数量随酸雨pH值的降低呈先升高后降低的变化趋势;绞股蓝茎叶总皂甙含量随酸雨pH值的降低而降低。酸雨影响下,单施低浓度的Zn(30 mg.kg-1)或Cd(1 mg.kg-1)时,根际3大类群微生物、氮素生理类群、纤维素分解菌、绞股蓝总皂甙含量均高于无重金属处理;但当Zn(400 mg.kg-1)或Cd(15 mg.kg-1)处于高浓度时,它们又明显低于无重金属处理。酸雨影响下,Zn(30 mg.kg-1)或Cd(1 mg.kg-1)为低浓度水平时,Zn-Cd复合污染对根际3大类群微生物、氮素生理类群、纤维素分解菌、绞股蓝茎叶总皂甙含量影响表现为拮抗效应;Zn(400 mg.kg-1)或Cd(15 mg.kg-1)为高浓度水平时,Zn-Cd复合污染对根...     

重庆农业生态系统中酸雨因子的特点及其影响

采用野外采样和室内分析,试验结果表明,酸雨对重庆区域农业生态系统影响不明显,菜地土壤有一定酸化趋势.农田大气中酸雨的主要因子SO2、NOx具有显著正相关,协同作用明显,但分布无明显规律性.农田灌溉水呈中性至微碱性,江水碱性明显.中性的灌溉水对土壤酸化有正面作用,碱性的灌溉水能阻止土壤酸化.不同种植类型土壤酸碱度差异明显,茶叶土壤为酸性,水果土壤则以碱性为主,因此可根据不同作物对土壤酸碱的喜好,调整种植品种和区域.