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1.
青藏高原大气降水化学组分特征及来源   总被引:1,自引:0,他引:1       下载免费PDF全文
为研究青藏高原大气降水无机离子组成特征及来源,2008年5~8月,在定日和聂拉木地区利用自动降水采集系统采集大气降水样品,并利用离子色谱对Cl-、NO3 -、SO42 -、NH4+、K+、Na+、Ca2、Mg2+8种无机离子浓度进行了分析.结果表明:定日、聂拉木降水中总离子浓度分别为390.6μeq·L-1和238.8 μeq·L-1,Ca2+浓度最高,分别为217.9 μeq·L-1和71.0 μeq·L-1,分别占离子总浓度的55.8%和29.7%.海洋源对定日降水中Cl-、SO42 -、K+、Mg2+和Ca2的贡献比例分别为98.3%、10.0%、29.3%、4.0%和0.7%;聂拉木分别为98.9%、45.0%、46.0%、16.7%、3.1%.气团后向轨迹结果表明:来自孟加拉、印度东北部和尼泊尔等地区的污染气团可能是定日和聂拉木降水中NO3 -、SO42 -的主要来源.  相似文献   

2.
叶玉新  纪凯  周密  李璟 《江西科学》2021,39(6):1046-1050
为了解江西省上饶市年内降雨变化特征,以上饶市丰溪河流域内降雨为研究区域,收集2020年3月至2021年2月中24 h降雨量大于等于5 mm的降雨.主要监测降水pH、电导率和常量离子浓度,以得到丰溪河流域内大气降水水质时空分布规律.调查数据结果表明:丰溪河降水时间分布极不均,降雨主要集中在3-9月,占全年降雨总量的87.1%,降雨量极差为657.8 mm,流域降雨呈现从南到北逐渐增强趋势,年最大降雨量流域北部的鹤山,年最小降雨量出现在流域南部的下会坑;酸雨频率为26.2%,全年pH平均值为5.79,有显著的季节差异,冬季<春季<秋季<夏季;SO42-、NH4+、Ca2+和NO3-为降水中主要离子,总无机离子加权平均浓度顺序为冬季>春季>秋季>夏季,与降水量呈负相关;降水离子与降水量加权年平均浓度分布规律为城区>郊区>农村>山区背景值站;SO42-/NO3-在1.66 ~4.91之间,平均值2.16,属硫酸-硝酸的混合型污染,人为源对大气环境产生了一定影响.  相似文献   

3.
酸沉降是当今重要的环境问题之一,中国南方已经成为继北美和欧洲之后的世界第三块酸雨集中分布区域.关于城市大气降水的化学性质在中国已有不少报道,但是在远离城市的偏远地区的大气降水化学性质的相关报导相对较少.本文初步分析了中国西南部偏远地区-雷公山国家级自然保护区2003-2004年大气降水的化学性质,发现雷公山区域2003-2004年的降水酸性较强,降水中Ca2 、NH4 、SO42-、NO3-是主要的阴阳离子组分,属硫酸型酸雨;降水各化学组分冬季浓度最高、夏季浓度最低;酸性污染物来自中远距离传输,雷公山降水中碱性物质较少,是降水呈酸性主要原因.  相似文献   

4.
对哈尔滨市大气环境中的PM10、PM2.5进行了采集,并对质量浓度及离子成分进行了分析.实验结果表明,两种颗粒物均呈现了先减小后增大的特征,最高值出现在1月,质量浓度分别是178.85、130.10μg/m3,PM10在1、2、3、4、11、12月均超标,而PM2.5质量浓度则高出欧盟标准(15μg/m3)的2~8倍,另外,离子总质量浓度在8月达到了最低值,分别是42.73μg/m3和25.3μg/m3.PM10和PM2.5中离子成分占颗粒物总质量的比例均表现为中间高两边低的特点,最高含量出现在7月份,分别为67.7%和68.4%.根据相关系数的判别原则,PM10中表现为高度负相关的离子是Ca2+和F-、Ca2+和SO42+、Ca2+和NO3-;表现为高度正相关的离子是K+和Mg2+、K+和Cl-、M2+和Cl-、F-和SO42+、F-和NO3-、SO42+和NO3-,说明上述离子间有相似的污染来源.PM2.5中表现为高度正相关的离子是K+和Cl-、K+和SO42+、K+和NO3-、Mg2+和SO42+、F-和NO3-、SO42+和NO3-,与PM10中离子相关性规律不同.  相似文献   

5.
铜陵市酸雨时空分布特征及其成因分析   总被引:1,自引:0,他引:1  
文章利用铜陵市2006-2010年的酸雨观测数据、降水化学分析资料和常规空气质量及气象资料,结合多种统计分析方法,系统地研究了铜陵市酸雨的分布特征、化学组成特征,并对其成因进行了初步探讨。结果表明:铜陵市的酸雨污染日趋严重,降水酸度在秋、冬季略高,郊区酸雨较城区严重;铜陵市的酸雨污染属于硫酸型,SO42-和NO3-是主要的阴离子,Ca2+和NH4+是主要的阳离子,各种离子浓度具有明显的局地差异,郊区低于城区,Ca2+和NH4+对降水酸度影响较为显著;铜陵市酸雨污染受区域性酸雨污染和本地污染源共同影响。  相似文献   

6.
广东云浮市降水的离子组成特征分析   总被引:2,自引:0,他引:2  
2005年4~9月在广东省云浮市采集到28场降水样品进行降水化学分析. 结果表明,SO42-和Ca2+是浓度最高的阴、阳离子,平均浓度依次为291.71eq/L和284.65eq/L, 占离子总浓度的75%;SO42-/NO3-的物质量浓度比平均为8.64, 降水污染主要为硫酸型;但降水中碱性离子对酸性离子的中和作用显著。另外,离子浓度高值出现在5月和8月的汛期过渡期, 低值则发生在6~7月的主汛期;除NH4+离子外,其他离子的月平均浓度的变化趋势比较类似,说明这些离子有相近的来源以及类似的传输途径。  相似文献   

7.
苏彬彬 《海峡科学》2011,(6):122-123
通过对2010年武夷山国家旅游度假区降水监测数据进行分析,了解度假区酸雨现状,并结合酸雨现状展开酸雨成因分析,得出结论:2010年武夷山国家旅游度假区降水pH均值4.66,电导率均值18.2us/cm,酸雨频率84.8%;NH4+是主要的阳离子,SO42-是对酸雨贡献最大的阴离子;降水的pH值、电导率、酸雨频率、Ca2+、SO42-和NO3-浓度均有明显的季节变化,NH4+浓度无明显的季节变化规律;外来源的煤烟型污染溶入降水,较少的颗粒物参与中和作用且颗粒物的缓冲能力低,以及长年过大的湿度是武夷山国家旅游度假区酸雨形成的主要原因。  相似文献   

8.
以湖南蔡家塘、贵州雷公山和重庆铁山坪3个小流域长年大气干沉降的监测数据为基础,对三地大气和气溶胶的化学成分的分布特征进行了分析研究.结果表明:三地大气干沉降中主要的酸性物质均为SO2,SO42-,NO2;主要的碱性物质均为NH+4,Ca2+,K+,NH3.SO2的干沉降跟当地S的来源有密切的关系,且具有季节性变化.三地...  相似文献   

9.
西安冬季大气亚微米颗粒物的化学特征及来源解析   总被引:6,自引:2,他引:4  
为了探讨西安市冬季大气亚微米颗粒物的污染水平及化学组成,2006年12月每天收集西安大气亚微米颗粒物(PM1.0)样品,并对PM1.0的质量浓度及其其中的11种水溶性离子、元素碳(EC)和有机碳(OC)及8个碳组分进行了分析.结果显示:西安市冬季大气PM1.0的平均质量浓度为149.7μg·m^-3分析的11种阴、阳离子(Na^+、NH4^+、K^+、Mg^2+、Ca^2+、F^-、Cl^-、Br^-、NO2^-、NO3^-和SO4^2-)的质量浓度占到PM1.0的46%,表明水溶性组分是大气亚微米颗粒物的主要组成之一;OC的质量浓度(ρ(OC)=(23.7±10.27)μg·m^-3)明显高于EC的((ρ(EC)=(4.6±1.8)μg·m^-3),碳气溶胶的平均质量浓度为42.5μg·m^-3,占到PM1.0质量浓度的28.4%;对8个碳组分的因子分析结果显示,燃煤及汽油车排放、柴油车排放和生物质燃烧对碳颗粒的贡献分别为45.3%、24.2%和23.5%.  相似文献   

10.
中国典型酸雨区大气湿沉降化学特性   总被引:4,自引:0,他引:4  
以湖南蔡家塘、贵州雷公山和重庆铁山坪3个小流域长年大气降水及森林穿透水的监测数据为基础,对三地的大气降水和森林林冠穿透水的化学成分的分布特征进行分析研究。研究结果表明:3个地区大气降水都已出现严重的酸化现象,大气降水多年平均pH从大至小的顺序为雷公山(4.96)、蔡家塘(4.62)和铁山坪(4.12);蔡家塘与铁山坪大气降水和森林穿透水中的阴离子均以SO42-为主,阳离子以NH4+为主;蔡家塘大气降水和森林穿透水中SO42-占总离子量的26.67%和24.14%,NH4+占总离子量的31.67%和23.69%;铁山坪大气降水和森林穿透水中SO42-占总离子量的54.73%和12.26%,NH4+占到总离子量的8.92%和59.14%;雷公山大气降水中的阴离子以Cl-为主,占总离子量的16.59%;阳离子以NH4+为主,占总离子量的20.99%;森林穿透水中的阴离子以SO42-为主,占总离子量的19.83%,阳离子以K+为主,占总离子量的16.73%;3个地区森林穿透水与大气降水相比,森林穿透水中的各种离子组分都发生了富集现象,蔡家塘、雷公山、铁山坪离子总量增加量分别为2.75倍、1.79倍和4.63倍。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

18.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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