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.     

实施种养结合循环利用模式后土壤重金属全量及有效态含量分析

分析双流县集约化养猪场和奶牛养殖场实施种养结合循环利用模式后土壤重金属全量及有效态含量变化,为评估土壤生态环境质量,及完善和推广该模式提供依据．采用ICP—OES和DTPA浸提法分别对研究区内土壤重金属全量及有效态含量进行测定,利用单因子指数法和内格罗污染指数对土壤重金属污染进行评价,应用SPSS软件对数据按不同养殖场采样地进行方差分析和LSD多重比较．结果表明,重金属全量铬元素对照组均高于猪场（P〈0．05）和奶牛场（P〈0．01）,铅对照组高于奶牛场（P〈0．01）,镉、铜对照组高于猪场和奶牛场（P〈0．01）;猪场、奶牛场与对照组比较,二者各元素单项污染指数Pi和综合污染指数PN均低于对照组;铅、砷有效态含量对照组高于奶牛场（P〈0．01）和猪场．结论：双流县集约化养猪场和奶牛养殖场实施种养结合循环利用模式后,土壤中铬、铅、铜和镉全量显著降低;铬、铅、铜、砷和镉的单项污染程度和综合污染水平降低;铅、砷有效态含量降低．     

矿物固化剂添加下土壤重金属有效性变化及污染风险评价

采集重金属污染原土为供试土壤,通过施加1%和2.5%的沸石、膨润土、硅藻土、蛭石4种矿物固化剂,研究矿物添加对土壤重金属全量、有效态、生物有效性及形态分级的影响,并评价其污染及生态风险.结果表明:添加矿物固化剂后土壤中Cu、Zn、Pb含量仍在土壤重金属污染管控筛选值范围内,其污染及生态风险均相对较低;矿物固化剂添加后可不同程度地降低土壤重金属有效态及生物有效性,且以硅藻土和蛭石处理效果相对较好;矿物添加后可能通过促进EXCH-Cd向FeMnOX-Cd转化而降低土壤中Cd的生物有效性;整体上,2.5%矿物固化剂下土壤重金属综合污染指数下降更为明显.综上,适量矿物固化剂添加可以降低土壤重金属有效性并控制其污染及生态风险.     

超声波对污染土中铅特定形态转化的影响

土壤重金属污染是当今亟须解决的环境问题之一,现有研究发现超声波辅助能够提高污染土壤中重金属的浸出率,影响土中重金属的形态转化,但研究尚未涉及具体转化方向。通过MBCR连续浸提法制得4种铅初始形态差异的土样,再分别对其进行超声处理,处理后测定土中的铅形态分布,通过与初始土样铅形态分布差异的对比分析,探究超声波单独作用对铅特定形态转化的影响。研究发现超声波处理可使土样中铅弱酸可提取态、可还原态含量增加,可氧化态、残渣态含量减少。说明超声波影响铅污染土壤中铅的特定形态转化,且效果与其作为辅助手段时增加重金属浸提量作用方向一致。     

白泥稳定化处理重金属污染土壤的研究

用白泥作阻隔剂通过土柱浸滤实验对土壤中重金属Cu、Zn、Cr、Pb的迁移规律和阻隔效果进行了研究.结果表明:白泥对重金属Cu、Zn、Cr、Pb有显著的阻隔效果,阻隔土样中白泥的含量别为3%、5%、8%、12%,随着白泥含量的增大,滤液的p H值和阻隔土层截留的重金属量增大,滤液中重金属浓度降低.重金属的存在形态对其在土壤中的迁移特性有一定的影响,在土样中加入白泥,重金属的稳定态含量增加,对土壤中重金属的迁移产生阻隔作用.     

吉林省西部土壤中重金属的形态及其潜在生态影响评价

在吉林省西部5种主要类型土壤中共采集土壤样品144件,对其中Hg、As、Cd、Zn、Cr、Cu、Pb、Ni等重金属的含量进行了测定,并采用7步连续提取法对土壤中重金属的形态进行了分析。结果表明吉林省西部草原区土壤中重金属的含量均低于国家土壤质量标准中的一级标准,重金属含量处于自然背景水平;从土壤重金属总量来看,土壤基本没有受到重金属的污染;土壤中As、Cr、Cu、Zn、Ni、Pb主要是以残渣态存在,其潜在生态影响较小;而Hg、Cd主要以腐殖酸结合态等活性态存在,其潜在生态风险相对较大;风沙土、盐碱土中Hg的生态风险大于其它类型土壤;而栗钙土、草甸土中Cd的生态风险大于其它类型土壤。     

稻草对土壤中铬的形态变化及微生物活性的影响

通过向添有外源Cr(Ⅵ)的土壤中施入一定量的粉碎稻草, 研究了稻草对土壤中铬的形态变化特征:包括Cr(Ⅵ)含量的变化、有效态铬含量的变化以及铬形态分布特征的影响. 实验结果表明, 施入稻草可以促进Cr(Ⅵ)的还原, 加快土壤中Cr(Ⅵ)和有效态铬含量的降低; 同时, 铬的形态分析表明, 施入稻草的土壤水溶态和交换态铬含量比未施稻草的土壤低, 而沉淀态和有机结合态铬含量比未施稻草的土壤高. 实验还探讨了稻草对Cr(Ⅵ)污染土壤微生物活性的影响. 结果表明, 施入稻草的土壤呼吸强度和微生物数量都比未施稻草的土壤高, 增施稻草对缓解Cr(Ⅵ)对土壤微生物的抑制作用有一定的效果.     

皂角苷对土壤中重金属铬的去除

采用生物表面活性剂皂角苷对人工铬污染土壤进行振荡提取试验,研究了在不同浓度、p H、振荡时间、土水比、提取次数条件下皂角苷对土壤中铬的去除效果,并采用连续分级的方法研究皂角苷处理前后土壤中铬的形态变化。结果表明,增加皂角苷浓度有利于提高铬的去除率,在皂角苷浓度为50 g/L时,铬去除率达到37.63%,而去离子水对铬的去除率不到10%;皂角苷溶液p H=1.5时铬去除率最大,且明显高于其他处理组;振荡初期铬去除率迅速增加,随着振荡时间延长,去除率增速逐渐减缓,振荡4 h和24 h的去除率分别为24.38%和30.35%;降低土水比和增加提取次数,铬去除率增加。皂角苷振荡提取土壤中的铬,能有效降低土壤中铬的毒性和生物可利用性,酸提取态铬和可还原态铬均减少50%以上。     

中药渣生物炭对污染土壤中Cu的修复

以中药渣为原料,采用限氧控温炭化法在300℃和500℃温度下制备生物炭,将其分别加入重金属污染土壤探究其对土壤中Cu的作用效果。土培实验结果表明:施加1%土重的生物炭后土壤中重金属Cu的形态发生迁移,主要是由有效态向残渣态转化,与对照相比,300℃和500℃生物炭培养下残渣态分别提高22.38%和20.11%,土壤中p H、有机质、CEC及碱解氮、速效磷的含量,脲酶、磷酸酶的活性在一定培养时间内有所增加,继而出现下降趋势。土壤阳离子交换量能较好地指示中药渣生物炭对污染土壤中Cu的钝化效果。300℃条件下制备的生物炭优于500℃条件下的生物炭。     

中国部分林地土壤重金属含量特征及污染评价

为掌握中国林地土壤重金属污染状况,选取中国13个具有代表性林地土壤,结合经典的重金属污染评价方法,分析土壤中重金属(铅、镉、铜、锌)的含量分布特征和污染程度,通过相关和回归分析,研究土壤理化性质对土壤重金属全量及有效态含量的影响。结果表明:不同地区林地土壤重金属含量波动较大,绝大部分位点土壤重金属含量均未超过GB 15618—2018中筛选值。以筛选值作为评价标准时,绝大部分土壤重金属单因子指数小于1,说明供试土壤重金属处于清洁与尚清洁状态;内梅罗综合指数评价结果显示,除武夷山、卧龙自然保护区土壤重金属处于警戒线等级外,其他地区均处于清洁。以管制值为评价标准时,土壤重金属污染指数以及内梅罗综合污染指数均处于小于0.7。潜在生态风险指数评价结果表明,研究区域大部分位点土壤中Cd存在中等或较高的潜在生态风险,土壤中重金属呈轻微等级的综合潜在生态风险。地质累积指数表明,大部分土壤重金属均存在不同程度的累积,其中部分样点Cd、Zn达到中度污染水平,累积效应更加显著。相关性与回归性分析显示,土壤pH与有效态Cu呈显著正相关性,基于土壤理化性质的多元回归方程可以较好地预测土壤中有效态Pb和Cu的含量,相关系数R~2分别达到0.962和0.895。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

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.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-