三(2-甲基苯并咪唑)-锰配合物的合成、表征及对催化H2O2岐化反应活性的增强作用

在乙醇溶剂中,通过Mn(Ⅱ)盐与N,N,N-三(2-甲基苯并咪唑)胺(NTB)反应合成了[Mn(NTB)(Im)]Cl2、[Mn2(NTB)2(H2NCONH2)]Cl4*3H2O、[Mn(NTB)(NO3)](NO3)*3H2O和[Mn(NTB)(HO-phen-OH)]Cl2 4种新配合物,并运用元素分析、摩尔电导、红外光谱和紫外光谱进行了表征.研究了配合物对H2O2岐化反应的催化活性,以及对过氧化氢模拟酶[Fe(NTB)Cl2]Cl*3H2O对H2O2岐化反应活性的影响.实验表明,所合成的锰配合物具有明显的活性增强作用.     

溶胶-凝胶法合成LiAl0.1Mn1．9O4及其电化学性能

通过溶胶-凝胶法合成LiAl0.1Mn1.9O4，XRD的结果表明掺杂少量的铝后并没有改变晶体的结构。利用恒流充放电测试手段比较研究了尖晶石型的LiAl0.1Mn1.9O4，XRD铝的掺杂后的LiAl0.1Mn1.9O4，XRD比没有掺杂的LiMn2O4更好的可逆性能，更好的循环性能。     

Cr--MnOx/TiO2--ZrO2低温选择催化还原NO的活性及抗毒性能

采用溶胶凝胶法制备TiO2-ZrO2载体,然后采用柠檬酸溶液浸渍法制备Cr-MnOx/TiO2-ZrO2复合催化剂.通过X射线衍射、比表面积测试( BET)、扫描电镜、X射线光电子能谱等测试方法对催化剂的物化性能进行表征分析,并进行NH3选择性催化还原NO实验,考察催化剂在低温下的活性及抗硫抗水性能. Cr元素介入到MnOx 中,形成了新型的CrMn1.5 O4活性物相,其中的Mn元素多以Mn3+和Mn4+存在.高价态的Cr5+使Mn元素由Mn3+向高氧化态的Mn4+转化,有利于低温选择性催化还原反应的进行.鉴于Cr元素第一电离能和电负性均低于Mn元素,能优先于Mn与SO2-4和SO2-3结合,保护MnOx 不被硫酸化,从而提高Cr-MnOx/TiO2-ZrO2催化剂的抗毒性能.制备的五种不同Cr/(Cr+Mn)摩尔比的催化剂中,Cr(0.4)-MnOx/TiO2-ZrO2的性能最优,其颗粒分散均匀,具有较大比表面积,在180℃时脱硝效率能够达到95.8%,同时通入5% H2 O和10-4 SO2,脱硝效率缓慢下降,反应8 h后,下降到73%,并保持稳定.     

超临界流体干燥制备纳米MnxOy

以硝酸锰和氨水为主要原料，用“溶胶-凝胶”法结合“超临界流体干燥”技术制备纳米MnxOy气凝胶，在800℃下煅烧MnxOy气凝胶，用XRD和TEM进行表征，重点考察超临界干燥、煅烧工艺对MnxOy气凝胶晶态、形貌和尺寸的影响。结果表明，采用超临界干燥，可制得分散性好的疏松棕黑色Mn3O4球形颗粒，其粒径介于10～30hm之间；在800℃下热处理，Mn3O4球形颗粒进一步氧化转变为米粒状Mn2O3颗粒，粒径也相应增大。     

一种廉价的功率铁氧体材料

进行了精铁矿粉代替氧化矿粉，Mn3O4代替MnCO3对制备功率铁氧体性能影响的对比实验，实验结果表明，选择最佳的配方和制备工艺，能用精铁矿粉和Mn3O4制备出性能接近PC3O的功率铁氧体。     

Mn（Ⅱ）与1，1，4，7，10，10—六（2′—甲基苯并咪唑基）三乙四胺的多核配合物的合成和表征

合成了3种新的锰（Ⅱ）的多核配合物，分别为Mn3(L)Cl6·12H2O（I），Mn2（L）Cl4·8H2O（Ⅱ）和Mn2(L)(NO3)4·9H2O（Ⅲ），其中L为1，1，4，7，10，10-六-（2′-甲基苯并咪唑基）三乙四胺（TTHB），由三乙四胺六乙酸与邻苯二胺共热缩合而得，根据配合物的摩尔电导，红外光谱，电子光谱和顺磁共振及元素分析，推测配合物中Mn（Ⅱ）的配位环境为四方锥或变形八面体。     

Mn_3O_4/CNTs正极材料的制备及其电化学性能研究

针对水系镁离子电池正极材料循环不稳定及电化学性能差的问题,采用Mn3O4作为水系镁离子电池正极材料,通过简单的溶液共沉淀法将Mn3O4与碳纳米管(CNTs)原位复合形成Mn3O4/CNTs。经X射线粉末衍射仪(X-ray diffractometer, XRD)、扫描电子显微镜(scanning electron microscopy, SEM)、通射电子显微镜(transmission electron microscopy,TEM)和循环伏安(cyclic voltammetry,CV)及充放电测试等表征,结果表明CNTs表面均匀附着尖晶石型Mn3O4纳米颗粒,提高了Mn3O4电极的导电性和电化学性能。Mn3O4/CNTs正极材料在100 m A/g下表现出305 mAh/g的比容量及长循环寿命,远高于Mn3O4的电池性能。Mn3O4/CNTs材料作为水系镁离子电池正极材料具有潜在的应用价值。     

LiBi0.01Ce0.03Mn1.96O4的合成和表征

通过共沉淀法合成同时掺杂铈及铋的锂锰氧化物LiBi0.01 Ce0.03Mn1.96O4,并用TG-DSC,XRD,SEM和FT-IR对其进行了分解温度,物相和显微结构等表征.结果表明适当的条件所合成的LiBi0.01 Ce0.03 Mn1.96O4具有与母体LiMn2O4同样完整的晶型和单一物相.     

溶胶凝胶法制备纳米级锂离子电池正极材料LiCrxMn2-xO4

通过溶胶凝胶法低温下合成了 Cr与 Mn不同计量比的一系列正极材料 Li Crx Mn2 -x O4 ,并用 DTA,TGA,TEM,XRD,FT- IR对其形貌及其结构进行了表征 .结果表明采用该方法在4 5 0℃的低温下即可得到纯相的 L i Crx Mn2 -x O4 尖晶石 ,其平均粒径均为 80 nm左右 ,且分布均匀     

氧烛中锰金属粒径对氯酸钠热解的催化作用

分别制备了两组粒径的Mn金属燃料(平均粒径分别为18.73和5.24μm),利用激光粒度分析仪测试了其粒径分布,扫描电镜分析了表面形貌,能谱仪确定了所含元素.对NaClO3,NaClO3与Co3 O4,NaClO3、Co3 O4与Mn的混合物分别进行了热重与示差扫描量热联合分析实验(TGA-DSC),通过对比各混合物热解起始温度及其他特征温度,探究了Mn金属粒径对NaClO3热解的催化强度与热解稳定性的影响.研究结果表明:Co3 O4虽对NaClO3热解具有催化性,热解开始温度(To)由512.3℃ 下降为333.0℃,但其可导致NaClO3热解的不稳定,热解阶梯由1个变为3个;Mn金属燃料对NaClO3中间产物具有明显的催化性,且随着粒径减小,催化强度逐渐增加,热解终止温度(Tf)由419.8℃ 下降为351.9℃,同时NaClO3热解阶梯减少,热解温度区间变窄(由180.6℃ 减小为19.4℃),热解更加稳定.     

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.     

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…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

<正>~~     

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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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