大气CO2倍增和盐度对滨藜离子水平和叶绿素荧光诱导动力学的效应

研究了ＣＯ２倍增和ＫＣｌ、ＮａＣｌ对盐生植物中亚滨藜幼苗生长，叶绿素含量，Ｋ＾＋、Ｎａ＾＋水平和叶绿素ａ荧光诱导动力学的影响。结果表明，３００ｍｍｏｌ／ＬＮａＯＨ可刺激中亚滨藜的生长，而同浓度的ＫＣｌ则抑制，ＣＯ２倍增使植物株生长增强：     

Seasonality of carbonaceous aerosol composition and light absorption properties in Karachi, Pakistan

Characteristics of carbonaceous aerosol(CA) and its light absorption properties are limited in Karachi,which is one of the most polluted metropolitan cities in South Asia.This study presents a comprehensive measurement of seasonality of CA compositions and mass absorption cross-section(MAC) of elemental carbon(EC) and water-soluble organic carbon(WSOC) in total suspended particles(TSP) collected from February 2015 to March 2017 in the southwest part of Karachi.The average TSP,organic carbon(OC),and EC concentrations were extremely high with values as 391.0±217.0,37.2±28.0,and 8.53±6.97 μg/m~3,respectively.These components showed clear seasonal variations with high concentrations occurring during fall and winter followed by spring and summer.SO_4~(2-),NO_3~-,K~+,and NH_4~+showed similar variations with CA,implying the significant influence on atmospheric pollutants from anthropogenic activities.Relatively lower OC/EG ratio(4.20±2.50)compared with remote regions further indicates fossil fuel combustion as a primary source of CA.Meanwhile,sea salt and soil dust are important contribution sources for TSP.The average MAC of EC(632 nm) and WSOC(365 nm) were 6.56±2.70 and 0.97±0.37 m~2/g,respectively.MAC_(EC) is comparable to that in urban areas but lower than that in remote regions,indicating the significant influence of local emissions.MACwsoc showed opposite distribution with EC,further suggesting that OC was significantly affected by local fossil fuel combustion.In addition,dust might be an important factor increasing MACwsoc particularly during spring and summer.     

藻华高风险期微囊藻在洱海中的垂直分布特征及其影响因素

大量微囊藻浮力调节及其垂向迁移是形成蓝藻水华的重要机制之一.为研究微囊藻的垂直分布特征及影响因素,以洱海北部湖心为监测点位,采用野外采样室内分析的方法,于2016年9—12月对微囊藻生物量、伪空胞体积、粒径等指标进行了测定.结果表明:9—11月微囊藻生物量逐月增长并于11月达到峰值（1.77 mg/L）,在12月出现下降（月均值为0.34 mg/L）;9月、11月微囊藻伪空胞体积（18.0~22.6 μm3/cell）较高,10月、12月较低（10.2~17.3 μm3/cell）;9—11月微囊藻的垂向迁移速率（5.4~14.5 m/d）、漂浮百分率（57%~96%）及群体粒径（91~305 μm）逐渐增大,12月明显减小.微囊藻生物量、伪空胞体积及群体粒径的垂直分布规律均表现为表层最高,中层次之,底层最低.9—11月,微囊藻在洱海中出现垂直分层现象,伪空胞提供的浮力作用和藻群体粒径作用大于风力扰动作用,促使微囊藻在水柱中主动迁移并聚集在水面;而在12月,风力扰动对微囊藻垂直分布的影响远超过浮力及粒径的作用,微囊藻在水柱中趋于均匀分布.研究显示,藻华高风险期微囊藻在洱海呈弱分层分布,且浮力及群体粒径是影响其垂直分布的主要因子.      

多元热流体项目风险评价技术的应用

多元热流体技术项目近年来在新疆油田开展了众多现场试验工作,取得了一定进展。项目现场装置区主要包括复合热载体发生器及其配套系统,项目实施过程危险有害因素较多。通过研究分析,对生产单元进行了划分,辨识了各单元危险有害因素,运用HSE风险评价工具对风险进行了评价,提出了对策措施。     

中国CDM项目开发现状及存在问题分析研究

清洁发展机制(CDM)是国际社会实现温室气体减排的履约机制之一。目前中国已成为CDM市场的主要输出国,但在CDM项目开发过程中还存在很多问题,例如区域分布不平衡、碳排放权交易标准不统一、缺乏激励机制等。在经济发展和节能减排的双重压力下,中国政府声明将严格遵守《巴黎协定》,正在积极落实已提出的到2020年控制温室气体排放行动目标,并向联合国提交了到2030年的"国家自主贡献"行动目标。中国的积极行动推动了全球气候问题的解决。     

Fluorescence regional integration and differential fluorescence spectroscopy for analysis of structural characteristics and proton binding properties of fulvic acid sub-fractions

Structural characteristics and proton binding properties of sub-fractions (FA3–FA13) of fulvic acid (FA), eluted stepwise by pyrophosphate buffer were examined by use of fluorescence titration combined with fluorescence regional integration (FRI) and differential fluorescence spectroscopy (DFS). Humic-like (H-L) and fulvic-like (F-L) materials, which accounted for more than 80% of fluorescence response, were dominant in five sub-fractions of FA. Based on FRI analysis, except the response of F-L materials in FA9 and FA13, maximum changes in percent fluorescence response were less than 10% as pH was increased from 2.5 to 11.5. Contents of carboxylic and phenolic groups were compared for fluorescence peaks of FA sub-fractions based on pH-dependent fluorescence derived from DFS. Static quenching was the dominant mechanism for binding of protons by FA sub-fractions. Dissociation constants (pKa) were calculated by use of results of DFS and the modified Stern-Volmer relationship. The pKa of H-L, F-L, tryptophan-like and tyrosine-like materials of FA sub-fractions exhibited ranges of 3.17–4.06, 3.12–3.97, 4.14–4.45 and 4.25–4.76, respectively, for acidic pHs. At basic pHs, values of pKa for corresponding materials were in ranges of 9.71–10.24, 9.62–10.99, 9.67–10.31 and 9.33–10.28, respectively. At acidic pH, protein-like (P-L) materials had greater affinities for protons than did either H-L or F-L materials. The di-carboxylic and phenolic groups were likely predominant sites of protonation for both H-L and F-L materials at both acidic and basic pHs. Amino acid groups were significant factors during proton binding to protein-like materials of FA sub-fractions at basic pH.     

光催化氧化法降解废气中苯系物的研究

采用溶胶-凝胶工艺制备以多孔泡沫镍为载体的TiO2薄膜，并用其光催化氧化降解挥发性苯系物(苯、甲苯和二甲苯)。考察了催化剂粒径、反应时间、苯系物的初始浓度、体系的相对湿度和反应温度等因素对苯系物去除率的影响。结果表明，以粒径20．7nm的TiO2为催化剂、甲苯初始质量浓度为200mg/m^3、体系的相对湿度为5％、反应温度为20—50℃、反应时间为60min条件下，甲苯的去除率达76％以上。     

云南边疆环境问题初探

云南边疆风景秀丽,资源富饶,但由于各种因素,云南边疆的环境受到了严重破坏。本文通过列举事实,对云南边疆环境破坏的现状与程度进行了详细阐述,并结合实例直言不讳地分析了边疆环境破坏的原因,尝试性地提出了保护云南边疆环境,实现边疆经济可持续发展的可行性建议。     

1951-2008年东北地区水分盈亏量时空格局

基于1951-2008年东北地区106个气象站点的实测数据,利用Penman-Monteith公式计算潜在蒸散量,并将气候水分盈亏量表示为同期降水量与潜在蒸散量之差。最后,通过Kendall秩次相关趋势分析、Morlet小波函数、Mann-Kendall突变检验等方法探讨了东北地区水分盈亏量的时空变化特征。结果表明:①1951-2008年,东北地区多年平均水分盈亏量在-850~650 mm之间变化,呈自东向西、自北向南、自东北向西南逐渐减少的空间变化趋势;②东北地区106个气象站点中有97个站点的水分盈亏量呈下降趋势,其中28个站点的下降趋势能通过P<0.05的显著性检验;③全区平均、海拉尔、长春、宽甸年际波动明显,多年平均值依次为-283.60、-427.25、-362.58、334.91 mm,四者的水分盈亏量年内分配不均匀,最小值出现在5月,最大值出现在7-8月;④水分盈亏量存在周期结构性,偏高期、偏低期交替出现,全区平均、海拉尔、长春、宽甸的第一主周期依次为26、28、25、9 a,水分盈亏量还具有突变特征,全区平均在1999年发生了一次减少突变,长春在1958、1998年各发生了一次减少突变。