无患子皂苷对土壤重金属Cr的淋洗修复

为修复日益严重的重金属污染土壤,采用无患子皂苷对土壤进行批次淋洗实验,考察了无患子皂苷浓度、淋洗时间、p H、提取次数对去除重金属Cr的影响。实验结果表明:浓度为21 g/L的无患子皂苷溶液对Cr的去除效果最好,去除率达到32.05%;随着淋洗时间、提取次数的增加,Cr的去除率也随之增加;降低无患子皂苷的p H值有利于去除重金属Cr。重金属形态变化分析结果表明,无患子皂苷可以较为有效去除弱酸提取态以及可还原态的金属,降低了金属存在于环境中的风险。     

MICP技术对Mn(Ⅱ)、Cr(Ⅵ)污染土壤的修复效果

利用微生物诱导碳酸盐沉积(microbially induced carbonate precipitation, MICP)技术处理Mn(Ⅱ)、Cr(Ⅵ)污染土及Mn(Ⅱ)、Cr(Ⅵ)混合溶液,研究MICP技术对重金属污染土的修复效果,重金属离子在土壤修复过程中的竞争关系,以及pH值对已修复土壤稳定性的影响.实验结果表明:经微生物矿化修复后,单一重金属污染土中可交换态锰、铬离子的去除率分别为85.64%和77.56%;经修复的Mn(Ⅱ)、Cr(Ⅵ)混合污染液中可交换态锰离子的去除率大于铬离子;酸性条件影响污染土的修复稳定性,土壤中可交换态锰、铬离子含量随pH值减小而增加.     

模拟降雨对铀在土壤中的迁移转化影响研究

运用室内土柱淋滤模拟实验,研究降雨量及其p H对土壤中不同形态铀迁移转化的影响。研究结果表明:1)土壤中总铀随淋滤量增大而降低; 2)土壤中总铀浓度随着淋滤液p H降低而降低; 3)经不同淋滤量淋滤后,土壤可交换态(水溶态)铀,碳酸盐结合态铀及有机质结合态随着淋滤量的增大而减少; 4)经不同p H淋滤液淋滤后,土壤可交换态(水溶态)铀与碳酸盐结合态铀含量随淋滤液p H的降低逐渐减少。     

复配还原剂对六价铬污染土壤的修复还原效果

探讨多硫化钙(CPS)和糖蜜对土壤中六价铬Cr(Ⅵ)的还原效果.在处理时间60 d条件下,多硫化钙和糖蜜单一还原剂对土壤Cr(Ⅵ)的去除率分别为99.31%和93.35%;4∶1、1∶1及1∶4的多硫化钙和糖蜜复配还原剂对土壤Cr(Ⅵ)的去除率分别为99.35%、99.53%和95.14%,对浸出性Cr(Ⅵ)去除率均达到98%以上.多硫化钙和糖蜜协同修复对土壤环境pH影响较小,单一使用多硫化钙可提高土壤pH值,单一使用糖蜜可降低土壤pH值.各处理条件均可使土壤中的铬元素由可交换态向铁锰氧化物结合态和残渣态转化,同一处理时间内,1∶1的多硫化钙和糖蜜复配药剂更有利于土壤铬从可交换态向难利用残渣态转化,且经济效益较优.     

不同固定剂对土壤中镉砷钝化修复效果研究

为了探究不同固定剂对镉和砷复合污染土壤的修复效果,以蚕沙炭(BC)、硅酸钙(Si)和硫酸亚铁(Fe)为材料,通过土培实验研究了不同处理在28 d平衡时间内对土壤基本性质和土壤中镉(Cd)、砷(As)有效态含量的影响。结果表明:单施1%(质量百分比)硫酸亚铁(Fe)和0.5%硫酸亚铁+0.5%蚕沙炭(Fe+BC)的处理可显著降低了土壤的p H值。单施1%硅酸钙(Si)、单施1%蚕沙炭(BC)、0.5%硅酸钙+0.5%蚕沙炭(Si+BC)、0.33%硅酸钙+0.33%硫酸亚铁+0.33%蚕沙炭等处理(Si+Fe+BC)则显著提高了土壤的p H值。除了Fe处理外,其他处理均提高了土壤有机碳含量,增加幅度为5.52%~26.95%。Si+BC和Fe+BC处理显著增加了土壤阳离子交换量(CEC),增加幅度分别为43.07%和20.62%,Si+Fe和Si+Fe+BC处理却显著降低了土壤CEC含量,降低幅度为16.06%和14.59%。Fe和Fe+BC处理极显著降低了土壤有效态As含量,分别降低了48.06%和33.75%;单施硅酸钙、单施蚕沙炭、硫酸亚铁+蚕沙炭处理显著降低了土壤有效Cd含量,分别降低了19.56%、14.29%、33.32%。相关分析结果表明,土壤p H值与土壤有效态As含量呈显著正相关关系,土壤中Cd的有效态含量与土壤CEC含量呈较好的显著负相关关系。综合考虑各处理对土壤中Cd、As的钝化效果,Fe+BC处理对复合污染土壤中Cd、As的钝化效果最佳,降低土壤有效态As含量为33.75%、降低土壤有效态Cd含量为33.32%。     

微生物与生物炭复合修复铬污染土壤的室内试验研究

以铬污染土为研究对象,通过浸出试验、Cr(VI)残留值试验、BCR连续提取试验研究了巴氏芽孢杆菌、生物炭及巴氏芽孢杆菌与生物炭复合对铬污染土壤的修复效果。结果表明：经过20 d修复后,上述添加剂均能够修复铬污染土壤,但菌液与生物炭复合的修复效果优于菌液和生物炭,且菌液的修复效果要优于生物炭;其中,当菌液浓度OD600 为1.0与生物炭浓度40 g?kg-1复合时,土壤浸出浓度和土壤中Cr(VI)含量分别从90 mg?L-1、270 mg?kg-1降低至1.08 mg?L-1、5.14 mg?kg-1,修复效果最好;同时,3种添加剂均提高了土壤的pH,均促使铬从弱酸态向可还原态和残渣态转化,而对可氧化态铬影响不大;由X射线光电子能谱分析（XPS）分析可知巴氏芽孢杆菌与生物炭复合修复铬污染土壤为混合吸附和还原的过程。     

生物法处理电镀铬废水的研究

主要研究生物法处理电镀铬 [Cr6 ]废水 .采用生物技术从电镀淤泥中分离出高效还原杆菌——脱硫孤菌 ,探讨菌量、铬离子浓度、溶液值、作用温度和时间等因素对还原杆菌去除溶液中铬离子效率 .结果表明 :在菌废比为 1∶ 1 .4 ,温度控制为 2 0～ 3 5℃ ,p H控制在5～ 7,最佳作用时间 1 6～ 2 0 h,[Cr6 ]=75 mg/L时 ,Cr6 去除率可达 99.9%.     

生物炭施用对污染红壤中重金属化学形态的影响

采用BCR分级提取的方法研究了2种不同生物炭施用对污染红壤中重金属Cu、Zn、Cd和Pb化学提取形态的影响.结果表明,生物炭施用提高了土壤pH值和有机质含量.实验土壤中重金属Cu、Zn、Cd和Pb均主要以残渣态存在(分别为86.11%、63.30%、66.24%、50%),施用鸡粪生物炭(P)后Cu、Cd和Pb的可还原态比例降低,Zn可还原态与Cu、Zn、Cd、Pb的酸可提取态和可氧化态的比例都有所增加.施用木屑生物炭(W)后Zn、Cd和Pb的可还原态比例降低,Cu、Zn、Cd和Pb的酸可提取态,Cu可还原态及Cu、Zn可氧化态的比例增加.总体来看,施用木屑生物炭(W)和鸡粪生物炭(P)后,Cu和Zn的残渣态所占比例分别降低了9.3%、27%,3.7%和16%,而Cd和Pb的残渣态比例分别增加了3.6%、3.0%,4.5%和3.7%,表明施用2种生物炭可以增加Cu和Zn的生物有效性,且施用P生物炭后增加的比例大于施用W生物炭;降低Cd和Pb的生物有效性,但施用2种生物炭后降低的比例相差不大.     

生物法处理油田废水影响因素研究

目的研究油田采油废水生物处理试验最佳试验条件及最佳试验条件下处理效果.方法生物处理试验分为厌氧试验和好氧试验两部分,分别通过单因素试验确定最佳试验条件,并且确定COD和NH+4-N的去除率.结果在厌氧生物处理阶段最佳试验条件:进水p H 7.4~7.6,温度37℃,水力停留时间(HRT)20 h,COD去除率平均为25.7%,NH+4-N质量浓度平均增长率为18.4%,聚丙烯酰胺(PAM)的平均去除率为10.3%,油的平均去除率为21.0%;在好氧生物处理阶段,最佳试验条件:进水p H 8.0~8.2,温度34~35℃,HRT 18 h,COD去除率平均值为51.3%,NH+4-N平均去除率为93.5%左右,PAM的平均去除率为30.9%,油的平均去除率为58.0%;结论生物处理油田采油废水较化学处理不仅成本低、操作简便,可以取得良好的处理效果,而且能够有效减少化学处理方式造成的污染,达到环境保护的目的.     

醋渣生物炭对土壤铬修复及苋菜萌发的影响

为了缓解重金属铬(Cr)给农田和作物带来的负面影响,将2%醋渣生物炭、2%市售土壤调理剂、基肥(由硫酸钾、磷酸二氢铵和尿素构成,施用量分别为0.05%、0.08%和0.08%)、2%醋渣生物炭+基肥施用于Cr污染的土壤中,对比各处理组对土壤修复及苋菜萌发的作用．结果表明：与对照组(5.12%)相比,醋渣生物炭可降低土壤弱酸可提取态Cr的相对含量(4.19%),但其他处理组会不同程度提升土壤中弱酸可提取态Cr的含量,土壤中弱酸可提取态Cr含量与pH(r=0.74)、脲酶活性(r=0.81)呈正相关,与过氧化氢酶活性呈负相关(r=-0.55)．醋渣生物炭可减轻弱酸可提取态Cr对苋菜幼苗的胁迫作用,使苋菜幼苗长势最佳(其干质量是对照组的3.5倍),作用效果优于市售土壤调理剂．该结果为耕地重金属钝化和作物生长研究提供了技术支持．     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the