Cu(Ⅱ)在谷氨酸根配合物体系中的电沉积行为

采用循环伏安法研究谷氨酸根配合物体系中谷氮酸根离子的稳定性和铜在阴极的电沉积过程,利用线性扫描伏安法求体系的表观活化能、表观传递系数和交换电流密度;计时电流法判断铜在电极上的成核方式.实验结果表明:在扫描电位-1.5～3 V内,谷氨酸钠溶液中仅有水的电解反应,谷氨酸根离子无氧化还原反应,铜在阴极沉秋时为不可逆过程;循环伏安曲线的感抗环说明铜在阴极沉积时经历了电结晶过程;由线性扫描伏安法求得表观活化能为34.065 kJ/mol,表观传递系数为0.360,电流交换密度为0.105 A/m2:铜在不锈钢电极上的成核方式为连续成核.     

三价铬的电化学沉积

通过稳态极化曲线、循环伏安、恒电流阶跃、交流阻抗等方法,研究柠檬酸水溶液体系中Cr3 的电沉积还原反应机理,确定Cr3 电沉积的动力学参数和动力学方程.研究结果表明,Cr3 的电沉积为电化学步骤控制过程,该电化学反应分2 步进行第1 步是Cr3 获得2 个电子还原为Cr ,为控制步骤和不可逆过程;第2 步是Cr 获得1 个电子还原为金属Cr,为准可逆过程;Cr3 在电沉积过程中无前置转化反应存在,但有电活性的中间产物吸附在电极表面;阴极和阳极表观传递系数分别为0.490 和2.455;化学计量数为1;阴极反应级数为1,阳极反应级数为0;扩散系数为1.606 × 10-5 cm2/s.     

那碎因极谱行为及其吸附特性的研究

考察了在NH_3-NH_4Cl底液中,那碎因的示波极谱行为。在pH 9.5的NH_3-NH_4Cl底液中该体系有一灵敏的导数极谱波,峰电位E=-1.51V(vs.SCE),峰电流i_p与那碎因浓度在0.10～7.0 μmol·L~(-1)范围内成正比,检测限为0.02 μmol·L~(-1)。用多种电化学方法确定那碎因在汞电极上的还原是属于反应物弱吸附的不可逆过程,吸附型体为中性分子,测得其在汞电极上的饱和吸附量Γ=0.781×10~(-10)mol·cm~(-2),电子转移数n=2,不可逆过程电子转移系数=0.56,扩散系数D=7.59×10~(-6)cm~2·s~(-1),电极反应速率常数k=8.32μm·s~(-1),并提出了电极反应机理。     

金属镍基体表面熔盐电沉积制备石墨涂层

在Li F-Li2CO3熔盐体系中电化学还原碳酸根离子,在镍阴极表面得到石墨涂层.通过循环伏安法研究了碳酸根离子的电化学行为,结合扫描电镜研究了温度和沉积电位对涂层表面形貌的影响,并对涂层性能进行了测试.结果表明:碳酸根电化学还原为碳的反应是一个不可逆过程;在690℃,-1.5 V电沉积时阴极表面形成了呈锯齿状结合的渗碳层.在-1.1 V电沉积时涂层表面形貌呈球形颗粒状,-1.5 V电沉积时涂层呈晶须状.石墨涂层使金属镍在3.5%的氯化钠溶液中的自腐蚀电位增加了739 m V.     

铁离子电还原过程的研究

用电位扫描法和旋转电极技术,研究了铁离子在铂电极和玻碳电极上的还原行为.结果表明该还原反应的可逆性明显地依赖于相伴阴离子的本性,在含SO_4~(2-)、NO_3~-、阴离子的溶液中,反应并非完全可逆,当溶液合Cl~-、CN~-离子时,电极反应是可逆的,而在F~-、C_2O_4~(2-)、Cit~(3-)、CNS~-、P_2O_7~(2-)等离子存在时,反应是不可逆的.实验证明,Fe~(2+)离子还原时,电极表面有吸附膜生成,此膜对H~+的放电析出有催化作用.从旋转电极实验求得1.0mol·dm~(-3)KCl溶液中,Fe~(3+)离子的扩散系数D_(Fe~(3+))=(7.9±0.1)×10~(-6)cm~2·s~(-1),标准速度常数k=(2.5±0.2)×10~(-3)cm·s~(-1).     

阴极共沉积Ni(OH)2薄膜在碱溶液中的电化学特性

采用阴极电沉积法在镍基底上制备Ni(OH) 2 薄膜 ,循环伏安法在 1 0mol·dm-3 KOH溶液中测量了薄膜电极的催化析氧特性 .沉积Ni(OH) 2 的薄膜电极比镍基底增加了 2 0mA·cm-2 的析氧电流 (1 0VvsHg/HgO电极 ) .在制膜过程中掺杂 7?(V/V)得到的复合氢氧化镍薄膜电极在碱溶液中的析氧电流又增加了约 2 0mA·cm-2 .分光光度法和薄层扫描分析法对薄膜进行了成分分析 .     

电沉积Ni-S合金析氢阴极的研究

以硫脲作为硫源,在瓦特浴体系中通过电沉积方法获得NiS合金电极·系统地讨论了电沉积过程中各工艺条件(硫脲浓度、电流密度、pH值及温度)对镀层中S含量的影响,确定了硫脲浓度和电流密度为NiS合金镀层中S含量的主要影响因素;以恒电流极化方法测试不同S含量的合金电极的析氢过电位,得到了析氢过电位仅为90mV的非晶态NiS合金析氢阴极;以稳态极化方法测定该电极的稳态极化曲线,并通过计算得出其电化学参数(b,i0)·结果表明,该电极具有极高的电化学活性·     

熔盐电解制取镧-镍合金的研究

用循环伏安法和电沉积后断电的电位-时间曲线对750℃和850℃下LaCl_3-NaCl-KCl熔体中镍电极的电化学行为进行了研究,获知镍电极还原过程中生成多个镧和镍的金属间化合物和析出金属镧。实验表明,用镍阴极电解LaCl_3-NaCl-KCl熔体,电解较适宜的条件是温度为850℃,电流密度为10Acm~(-2)附近,熔体中含LaCl_3在30wt%左右。     

铜离子对镍在玻碳电极上电结晶行为的影响

利用循环伏安法和恒电位阶跃技术,研究浓度为0.01mol/L铜离子对镍在玻碳电极上电结晶行为的影响。研究结果表明:在含0.01mol/L铜离子的Watts镀液中,电位在-0.3V左右出现铜的还原反应峰,当电位负移到-0.75V时,镍开始结晶沉积;与纯Watts镀液(电位约-0.85V)相比,铜离子的引入促进了镍的电结晶形核和生长,这是因为铜离子的存在降低了镍电结晶形核过电位;在含0.01mol/L铜离子的Watts镀液中,电结晶过程仍基本遵循Scharifker-Hill模型,铜离子的引入并没有改变镍电结晶行为;高负电位下,金属离子的结晶成核方式遵循瞬时成核机制,低负电位下则趋向遵循连续成核机制。     

铝电解中的阴极过程

对铝电解中的阴极反应、阴极过电压、阴极表面的双电层结构等阴极过程进行了研究,发现在+005～-005V(相对于铝阴极)电位区有一个还原电流峰和一个氧化电流峰,它们是Al3++3e→Al和Al-3e→Al3+·与阳极相比,阴极过电压较小,在001～3A/cm2的Taffel区,约为01V·在阴极表面的双电层中,第一层为Ca2+,Mg2+,Li+和Al3+离子,没有Na+离子,这说明,阴极过电压是因为Mg2+,Ca2+等离子形成的电化学双电层阻力所引起,同时也说明别略耶夫猜想基本是正确的·     

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).     

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.     

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.