硝基苯在钢渣-Fe(Ⅱ)系统中的还原转化

研究了钢渣含铁废物,以及添加Fe(Ⅱ)后钢渣-Fe(Ⅱ)体系对硝基苯还原转化的可行性及化学机理.实验在20±2℃及转速为30 r.min-1条件下进行,结果表明,单独钢渣体系对硝基苯的吸附和还原转化能力有限,其还原能力与钢渣本身残存的还原活性组分Fe(0),FeO有关.钢渣与Fe(Ⅱ)的表面结合系统能够提高硝基苯的还原转化速率.溶液中钢渣量大于12 g.L-1时,混合液pH值范围为11~12,硝基苯可在1h内完全转化.降低钢渣用量使混合液酸碱度稳定在中性,硝基苯转化速率减慢,高效液相色谱分析结果证实硝基苯还原转化遵循硝基苯→亚硝基苯→羟基苯胺→苯胺的途径.     

Staphylococcus saprophyticus JJ-1协同所合成的钯纳米颗粒还原邻氯硝基苯

研究细菌合成纳米颗粒原位还原硝基苯类污染物,为废水中有机物的去除提供参考和思路.首先利用Staphylococcu. saprophyticus JJ-1还原氯钯酸钠合成生物钯纳米颗粒(Bio-Pd NPs),采用一系列表征技术对所合成的Bio-Pd纳米颗粒的形貌、尺寸、晶型进行分析.进一步,利用"S. saprophyticus JJ-1/Bio-Pd"复合体系,还原转化邻氯硝基苯(O-Chloronitrobenzene,2-CNB),利用气相色谱-质谱联用仪(GC-MS)和高效液相色谱仪(HPLC)对2-CNB的还原途径和还原产物进行分析.结果表明,S. saprophyticus JJ-1能够合成Bio-Pd NPs,并于所合成的Bio-Pd NPs协同作用催化邻氯硝基苯的还原. GC-MS分析显示,邻氯硝基苯的还原产物为邻氯苯胺、硝基苯以及苯胺,说明在此体系下既可以实现硝基还原又可以进行脱氯反应. HPLC对邻氯硝基苯及其还原产物的定量分析显示,邻氯苯胺、硝基苯为中间产物,苯胺为最终产物.此外,研究结果表明,为建立还原2-CNB的"S. saprophyticus JJ-1/Bio-Pd"复合体系,最适的氯钯酸钠浓度为0.2 mmol/L,邻氯硝基苯的浓度上限不应超过0.6 mmol/L. S. saprophyticus JJ-1能够快速的合成Bio-Pd NPs,并于所合成的Bio-Pd NPs构成协同体系,很好地催化邻氯硝基苯(2-CNB)的还原转化.     

纳米Ni/Fe双金属还原降解对氯硝基苯的影响因素

利用自制的纳米Ni/Fe双金属对对氯硝基苯(p-NCB)催化脱氯进行研究,考察了镍化率、Ni/Fe投加量、反应温度、初始pH值和p-NCB初始浓度等反应参数对脱氯效果的影响.研究结果表明,反应产物为苯胺和Cl-;较高的镍化率、Ni/Fe投加量和反应温度可以促进p-NCB的还原降解;初始pH值有最佳浓度范围,较高pH值和较低pH值都不利于反应的进行.     

空气氧化法制备Fe3O4的反应机理

采用空气氧化法制备Fe3O4,分析反应过程中pH值随时间变化曲线和Fe的形态变化规律：用XRD和SEM检测反应各个阶段沉淀物的物相组成和形貌变化。研究结果表明：在中性和酸性介质中,Fe3O4的生成分3个阶段：Fe（OH）2悬浮液氧化为绿锈,绿锈转变为球形Fe3O4,Fe3O4氧化为针形FeOOH）氧化反应发生在液相,随着氧化的进行,pH值和液相Fe^2＋浓度发生改变,Fe3O4粒度不断增大;制备Fe3O4时,应控制pH值大于5．4,固相Fe（Ⅲ）与Fe（Ⅱ）的摩尔比小于1．8。     

乙醇重整制氢对邻氯硝基苯的原位加氢合成邻氯苯胺的研究

制备了两种PVP稳定的负载型稀土金属催化剂, 考察了其催化邻氯硝基苯（o-CNB）选择加氢制备邻氯苯胺（o-CAN）的催化性能. 所用氢气通过乙醇的液相催化重整产生并直接用于邻氯硝基苯的原位加氢. 评价了不同反应条件（温度、时间、Fe修饰剂等）对邻氯硝基苯的选择加氢的影响. 研究表明, PVP-La/γ-Al2O3催化剂比另一贵金属催化剂PVP-Pd/γ-Al2O3拥有更好的催化性能. 同时, 在优化的条件下, Fe修饰的PVP-La/γ-Al2O3催化剂催化的邻氯硝基苯选择加氢反应中, o-CNB的转化     

利用除尘灰合成非正分铁的氧化物

为了研究N2H4·2H2O的用量及pH值对产物的影响,以除尘灰的H2SO4浸渍液经铁粉还原得到的FeSO4溶液为原料,采用一步水热法,用水合肼(N2H4·2H2O)在碱性介质中氧化合成非正分铁的氧化物(γ-Fe2O3)x(Fe3O4)1-x (0≤x<1).通过控制溶液的pH值可以得到纯Fe3O4组分,将其磁性能与Fe(Ⅲ)/ Fe(Ⅱ)比为2.0的浸渍液直接水热合成的Fe3O4的磁性能进行了比较,结果表明:除尘灰的H2SO4浸渍液中加入铁粉还原所得FeSO4,经N2H4·2H2O氧化制得的样品的磁性能优于后者.     

大花绿绒蒿内生真菌Neurospora sp.DHLRH-F次级代谢产物研究

为了研究藏药大花绿绒蒿内生真菌Neurospora sp.DHLRH-F的次级代谢产物,采用硅胶、C-18反相硅胶、Sephadex LH-20等柱色谱及HPLC技术对其发酵物进行了系统分离;采用波谱分析技术进行化合物结构鉴定;采用光度法研究所得化合物对Fe2+,Fe3+的络合能力。结果从大花绿绒蒿内生真菌Neurospora sp.DHLRH-F的发酵物中分离得到3个多羟基化合物,分别鉴定为2-氯-6-甲氧基间苯二酚(1)、6-epi-5'-hydroxy-mycosporulone(2)、霉酚酸(3)。本文是首次关于绿绒蒿属植物内生真菌次级代谢产物研究的报道;分离得到的化合物1是新天然产物,有一定的络合Fe3+能力。     

Fe/Cu催化还原去除饮用水消毒副产物三氯乙酸

以高致癌风险的饮用水卤化消毒副产物(halogenated disinfection by-products,HDBPs)三氯乙酸(TCAA)为去除目标物,研究了Fe/Cu催化还原去除TCAA的效果,包括Fe/Cu质量比、Fe/Cu混合物投加量、pH值、有机物浓度和摇床转速等因素对Fe/Cu催化还原去除TCAA的影响.结果表明,Fe/Cu能够有效脱除TCAA,m(Fe):m(Cu)为10:1时的TCAA去除效果最佳;Fe/Cu最佳投加量为30 g·L-1;Fe/Cu还原脱氯去除TCAA最佳pH值在4～8之间;有机物浓度对Fe/Cu还原脱氯存在负面影响;在摇床转速、反应时间、投加量、pH值和UV254分别为200 r·min-1,160 min,30 g·L-1,6.82和0.117 cm-1的条件下,Fe/Cu催化还原对TCAA的去除率达到97.39%,并且Cu未被消耗,外扩散Fe/Cu催化还原反应的影响可以忽略,Fe/Cu对TCAA的催化还原脱氯降解过程符合拟一级反应.     

Q235碳钢在西沙大气暴晒的锈层特征

在西沙群岛高温、高湿的海洋大气环境下对Q235碳钢进行了3个月的暴晒实验,利用电子探针、激光拉曼等观察分析了暴晒后样品的锈层特征. 结果表明:Q235碳钢暴晒1个月后迅速形成较厚的锈层,锈层疏松多孔,多裂纹;当暴晒3个月时,锈层却明显减薄. Q235碳钢在西沙暴晒1个月后形成的外层腐蚀产物主要是γ-FeOOH、β-FeOOH、α-FeOOH及少量Fe3O4等,而锈层内部主要为Fe3O4、γ-Fe2O3等铁的氧化物. 暴晒3个月后,疏松锈层的内部电解液蒸发加剧,内层还原后的锈层重新被氧化,生成较多的FeOOH,同时部分γ-FeOOH转化成为α-FeOOH. Q235碳钢在西沙大气环境下的暴晒过程(也就是锈层的氧化还原反应的交替过程)中,钢基体不断地被腐蚀.     

铁柱撑蒙脱石表面介导的Fe(Ⅱ)还原体系对邻硝基苯酚的高效去除

通过引入铁氧化物并煅烧处理对蒙脱石进行优化设计,成功合成了铁柱撑蒙脱石复合催化剂(FPMt).采用X射线衍射(XRD)、热重分析(TG)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FT-IR)、N₂吸附-脱附(BET)等分析方法对FPMt样品结构与表面性质进行表征,以邻硝基苯酚(2-NP,22 μmol/L)作为代表性污染物研究FPMt的还原催化活性. 结果表明:与蒙脱石相比,FPMt表面电子传输活性得到明显提高,原因是引入赤铁矿的FPMt吸附位点增多同时酸位减少,从而显著增强材料表面的还原催化活性. 除溶液pH和Fe(Ⅱ)浓度外,催化剂的结构完整性、赤铁矿的结晶度等均为影响催化剂还原活性的重要因素. 最后提出了FPMt表面络合态Fe(Ⅱ)的还原催化活性显著提高的介导机制.     

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.     

A computer generator for randomly layered structures

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

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.