淮南采煤沉陷水体中氮磷的分布特征及环境意义

煤炭资源的大规模开采,导致高潜水位采煤沉陷区积水面积迅速扩展.以淮南市7个矿区典型的采煤沉陷水体为研究对象,测试分析了水体中氮、磷等水质指标并进行了水质评价.结果表明:1研究区沉陷水塘的总氮(TN)、氨氮(NH4+-N)、硝态氮(NO3--N)与总磷(TP)的平均值分别是3.04,0.61,0.61和0.16mg/L,水体的氮磷负荷较为严重;2沉陷区水体中TN分布为新庄孜矿(5.58mg/L)潘一矿(4.07mg/L)顾桥矿(2.77mg/L)潘三矿(1.79mg/L)朱集和潘北矿(1.47mg/L)潘二矿(1.17mg/L),TP分布为潘三矿(0.29mg/L)新庄孜和朱集矿(0.20mg/L)顾桥矿(0.17mg/L)潘北矿(0.14 mg/L)潘一矿(0.11 mg/L)潘二矿(0.05 mg/L),TN分布与沉陷时间具有良好相关性,而TP分布没有明显规律;3沉陷区的TN和TP相关性不显著,TN和NH4+-N具有良好的正相关,温度、溶解氧、pH与氮磷指标具有一定的相关性,综合水质标识法评价结果显示,研究区水体中的氮磷水平基本处于Ⅲ类或者超过Ⅲ类水,水体中最主要的超标和污染因子是TN,其次是NH4+-N.     

大亚湾表层沉积物中磷的形态分布特征

沉积物中不同形态的磷具有不同的生物有效性和地球化学行为,它们的含量和分布特征包含着许多环境地球化学信息。因此,对沉积物中磷的地球化学形态的研究具有重要的环境地球化学意义。采用SEDEX法将大亚湾表层沉积物中不同形态的磷分离开,继而分析表层沉积物中不同形态磷的含量、分布特征及其影响因素。结果表明,表层沉积物中总磷的含量较高,平均高达341.87 mg/kg;无机磷所占的比例很高,平均达85.11%,平均含量为290.81 mg/kg;有机磷的平均含量为51.05 mg/kg。表层沉积物中的碎屑态磷是无机磷的主要赋存形态,平均占无机磷的47.67%;其次为自生磷灰石及钙结合态磷,平均占无机磷的34.79%;铁结合态磷和吸附态磷分别仅占无机磷中的10.23%和7.31%。其中,潜在的生物有效性磷(包括Ads-P、Fe-P和OP)平均占总磷的29.40%。在空间分布上,各站间不同形态磷的含量差异与污染物的陆源输入、沉积物性质等因素有关。     

污水灌溉区土壤非饱和带氮分布特征

以徐州市铜山区奎河段两岸的农业灌溉区为例,结合当地典型的4种不同种植方式,对非饱和带土壤中的硝酸盐氮和铵氮质量比及其分布特征进行分析。结果表明:土壤中硝酸盐氮质量比为3.8~128.1mg/kg(平均33.0mg/kg),铵氮质量比为2.3~5.7mg/kg(平均3.8mg/kg);非饱和带土壤中氮主要来自常年施肥和污水灌溉;由于不同种植方式具有不同的施肥和灌溉条件,因此土壤中氮的分布亦不同;在接受地表灌溉和施肥补给之后,硝酸盐氮主要以下渗迁移为主;铵氮在下渗过程中会产生吸附作用,其质量比与土壤中黏土颗粒的含量呈一定的相关性,但在常年灌溉的水稻-冬菜种植点,在表层土中尽管黏土颗粒含量不高,铵氮质量比仍然较高。     

江浙地区茶园土壤碱解氮空间异质性分析

利用地统计学及空间插值方法分析了江浙地区4个茶园土壤碱解氮的空间分布特征及其变异情况,并探讨了其影响因素。结果表明:4个茶园土壤碱解氮含量均值由高到低依次是龙井村(108.85mg/kg)溪龙乡(101.61mg/kg)东山镇(98.02mg/kg)天目湖镇(81.08mg/kg),浙江省两个茶园的土壤碱解氮含量平均水平高于江苏省的两个茶园。4个茶园土壤碱解氮分布不同:天目湖镇和龙井村为球状模型,东山镇为指数模型,溪龙乡为高斯模型。浙江两地茶园土壤碱解氮具有较强空间相关性,江苏两地茶园土壤碱解氮具有中等空间相关性。生产方式(施肥管理)是土壤碱解氮分布的主要驱动因素,4个种植区内土壤碱解氮含量普遍偏低,偏低区域所占比例为天目湖镇85.08%、东山镇96.35%、溪龙乡91.08%和龙井村87.96%,极少区域(各地均不超过5%)土壤碱解氮含量偏高,可采用分区管理的措施施加氮肥,利于茶叶产量和品质的提高。     

獐子岛附近海域沉积物中氮和磷的分布来源及污染风险评价

【目的】为探讨北黄海獐子岛附近海域氮、磷的来源及其污染风险状况,对该海域表层沉积物中氮、磷的形态和分布特征进行分析。【方法】采用K2S2O8氧化法和HCl浸取法对獐子岛附近海域13个站位的表层沉积物中总氮(TN)、总磷(TP)及其无机和有机态的含量进行分析,并采用单因子标准指数法对氮、磷的污染水平进行评价。【结果】獐子岛附近海域沉积物中TN和TP的含量分别为0.192~1.357 mg/g和0.302~0.489mg/g,有机氮(ON)和无机磷(IP)是表层沉积物中氮和磷的主要存在形式,分别占TN与TP的90.93%和82.84%。沉积物中TN和TP在研究区域南部含量较高,这与沉积物粒度密切相关;而ON、有机磷(OP)两者都与有机碳(TOC)含量具有显著相关性,说明它们具有相似的来源。单因子标准指数法分析表明獐子岛附近海域沉积物中TP含量较低,标准指数均小于1;而TN含量相对较高,其标准指数为0.35~2.47。【结论】獐子岛附近海域沉积物中氮为陆源和自生混合来源,而磷主要是陆源输入;海域沉积物环境受到氮的污染。     

云南红壤氮素形态分布研究

采用分级连续浸取分离法研究了云南省陆良县4个不同地域土壤中氮的形态分布特征,结果表明:可转化态氮平均含量占总氮平均含量的51.63%⁸0.88%,土壤中可利用氮含量较高;离子交换态氮平均含量占可转化氮平均含量的5.08%80.88%,土壤中可利用氮含量较高;离子交换态氮平均含量占可转化氮平均含量的5.08%¹5.31%,弱酸可浸取态氮占可转化氮平均含量的21.82%15.31%,弱酸可浸取态氮占可转化氮平均含量的21.82%³8.70%,强碱可浸取态氮占可转化氮平均含量的25.07%38.70%,强碱可浸取态氮占可转化氮平均含量的25.07%³9.72%,强氧化剂可浸取态氮占可转化氮平均含量的19.65%39.72%,强氧化剂可浸取态氮占可转化氮平均含量的19.65%⁴2.34%,各采样点土壤氮形态分布受土壤pH、有机质含量、粒度等因素影响较大.     

水坝拦截对新安江沉积物中磷、氮形态的影响

以新安江水库及其相关河段为研究对象, 对沿程上游河段、库区河段、中心库区及坝后河段沉积物中的磷、氮地球化学形态、含量及分布特征进行了研究. 结果表明: 受上游颗粒物的沉积作用和水产养殖的影响, 库区河段的总磷(total phosphorus, TP)、总氮(total nitrogen, TN)分别比上游河段增加了37.3%, 34.2%. 受到大坝的拦截作用, 库区和坝后河段中的磷、氮含量明显降低, 坝后沉积物中的TP, TN分别比坝前降低了39.5%, 74.1%. 在磷的各形态中,钙结合磷(Ca-P)(13.8%∽31.9%)和铁结合磷(Fe-P)(11.5%∽26.2%)在TP中所占比例仅次于有机磷(organic phosphorus, OP)(48%∽69%). 受水库蓄水顶托的作用, 大量沉积的有机磷逐渐矿化降解, 并向铁结合磷转化, 导致坝前、坝后沉积物中的磷形态组成发生了明显改变. 有机氮(organic nitrogen, ON)为TN的主要形态, 在上游河段中ON含量较低, 但在库区河段迅速升高, 而在下游河段迅速降低, 而氨氮(NH⁺₄ -N)含量变化较小. 研究结果表明, 水库对磷、氮具有明显的拦截效应, 并改变了营养元素之间的化学计量比.     

黄河三角洲湿地表层土壤磷形态分布特征

2016年10月采集了黄河三角洲典型湿地的表层土壤,并采用SMT(standard measurements testing program)法分别提取了土壤中的TP (total phosphorus)、IP (inorganic phosphorus)、OP(organic phosphorus)、Fe/Al-P (Fe/Al-bound phosphorus)以及Ca-P (Ca-bound phosphorus)．结果表明,土壤中TP的平均质量分数为581.02 mg·kg?1,高于第2次全国土壤普查中土壤TP的平均质量分数．各形态磷质量分数分布从大到小依次为IP、Ca-P、OP、Fe/Al-P,IP约占TP总量的86.98%,是黄河三角洲含量最高的磷形态,而Ca-P则是IP的主要组分,约占IP的85.30%．各形态磷含量在黄河三角洲的分布具有较高的空间异质性,特别是OP和Fe/Al-P,变异系数分别达到了40.20%、39.41%．总的来说,距离黄河比较近的样点土壤中TP和IP含量都较低,有植被分布样点的土壤中OP含量较高．相关性研究表明,TP、IP均与土壤含水量呈现显著的负相关关系,OP与土壤碳质量分数(w(C)/w(P)、w(TOC)、w(TIC))呈现显著的正相关关系,Fe/Al-P和地形因子SOS呈现显著的正相关关系．主成分分析(PCA)也表明IP更容易受到湿地理化性质的影响,而OP和湿地土壤营养水平有很大关系．      

闽江感潮河段非雨季、雨季不同形态氮的时空分布及影响因素

选取非雨季(2018年11月)和雨季(2019年4月)对闽江感潮河段7个断面进行水样采集,研究不同季不同形态氮的时空分布规律,采用相关性分析及主成分分析并结合2016—2019年来水情况,深入探讨不同季氮组分分布及转化的影响因素.结果表明:1)非雨季盐水入侵明显,各理化指标盐度、温度、pH和溶解氧的波动均强于雨季.2)非雨季上游NH₄~+-N低于雨季,下游则高于雨季,而非雨季NO₃~--N和总氮(TN)总体均高于雨季.从上游到下游,非雨季NH₄~+-N变化波动较大,NO₃~--N平缓而TN呈轻微上升;雨季NH₄~+-N、NO₃~--N和TN变化均较平缓.3)相关性分析表明非雨季的氮转化活跃.雨季NH₄~+-N浓度是影响TN浓度的主要因素.结合主成分分析及长期上游来水氮的污染负荷发现,人为排放和各形态氮的相互转化是非雨季不同形态氮变化的主要因素,雨季水体反硝化对不同形态氮的分布发挥重要作用,而上游来水的氮污染负荷对不同形态氮的浓度影响较...     

新疆沙湾县农田土壤养分空间变异性研究

通过野外采样和室内分析,应用地理信息系统和地统计学分析相结合,对新疆沙湾县农田土壤碱解氮、速效磷、速效钾和有机质的空间分异进行研究。结果表明:与全国第二次土壤普查相比,沙湾县农田土壤中的有机质(12.4 g/kg)、速效钾(195.3 mg/kg)含量呈降低趋势,碱解氮(86.7 mg/kg)、速效磷(16.2 mg/kg)含量有所增加。土壤各养分的变异系数均表现为中等强度的变异,块金值和基台值之比为0.25-0.75,属于中等空间自相关,碱解氮含量在60-90 mg/kg的占了研究区的67.93%,速效磷含量10-20 mg/kg的占了研究区的74.98%,速效钾的含量大于150 mg/kg的占了研究区的94.85%,有机质含量在10-20 g/kg的占了区域面积的71.21%。本研究结果可为该区域的合理施肥提供理论依据。     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Design and analysis of generic LBS application developing platform

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that