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研究了TBP对N,N-双取代单酰胺萃取铀的影响,发现TBP浓度低时存在的协同效应,TBP浓度高时出现反协萃现象。结合体系物理化学性质对上述实验结果进行了讨论。堆积模型结果表明协萃合物结构处于堆积稳定区。 相似文献
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研究了TBP对N,N-双取代单酰胺萃取铀的影响,发现TBP浓度低时存在协同效应,TBP浓度高时出现反协萃现象.结合体系物理化学性质对上述实验结果进行了讨论.堆积模型结果表明协萃合物结构处于堆积稳定区. 相似文献
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研究了三烷基胺(N235)和磷酸三丁酯(TBP)从盐酸介质中对铼的协同萃取.N235和TBP的浓度比为1∶9时混合萃取体系对Re(Ⅶ)具有较大的协萃作用,最大协萃因子为4.71,对Mo(Ⅵ)的协萃因子为2.16.在pH=1时,萃合物的组成为(R3NH+Cl-)2·HReO4·B,当酸浓度为3 mol·L-1时,萃合物的组成为(R3NH+Cl-)·HReO4·B,而N235单独萃取时萃合物的组成为R3NH+ReO-4.同时证明了混合萃取剂分离钼和铼的协萃效果和萃取能力. 相似文献
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报道了几种常用的萃取剂从盐酸溶液中革取In3~+的性能分析。发现在较高的盐酸浓度下,N235、TBP萃取In~(3+)的能力均较大,分配比达到最大时所对应的盐酸浓度随萃取剂浓度的增加而减小。初步探讨了N263-MIBK,N235-MIBK,N235-N263从盐酸溶液中苹取In~(3+)时的协同作用,发现对In~(3+)均有明显的协同效应。对于N263-MIBK,协萃分配比在N263和MIBK的浓度分别为0.08 mol/L,4.8 mol/L时达到最大,最大值为580。改变盐酸浓度和温度,协萃分配比亦有较大的变化,但协萃比变化不大。在盐酸浓度为4.5mol/L时,协萃分配比达到最大。 相似文献
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研究了4,4′-壬二酰基-双(1-苯基-3-甲基-5-吡唑酮)(H_2A)与磷酸三丁酯(TBP)对铀(Ⅵ)的协同萃取行为,用斜率法测定了协萃合物的组成为UO_2A·TBP,求得协萃平衡常数logK_(se)为1.49,推测了协萃合物的可能结构。 相似文献
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本文研究了磷酸三丁酯(TBP)——三辛胺(TOA)——环己烷体系在硝酸盐介质中对U(Ⅵ)的协同萃取,发现该体系有弱协萃效应,用斜率法确定协萃络合物组成为(R_3NH)UO_2(NO_3)_3·TBP。少量TOA加入到TBP后,能减少TBP的辐解。 相似文献
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本文研究二苯甲酰甲烷(DBM)与二苯基亚砜(DPSO)及磷酸三正丁酯(TBP)的甲苯溶液从高氯酸钠底液中对U(Ⅵ)的协同萃取。发现有显著的AB类二元协萃效应,但ABB类三元协萃效应不很显著。测得萃合物的组成分别为UO_2A_2、UO_2A_2·DPSO及UO_2A_2·TBP。讨论了萃合物的可能结构式。求得25℃时各萃取反应的平衡常数。 相似文献
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有机亚砜(R_2SO)具有与路易士酸配位的能力,多碳亚砜水溶性小有些又可从石油副产物中获得,所以它们作为萃取剂在无机物溶剂萃取方面受到重视。关于二正丁基亚砜(DBSO)和一酸性螯合剂对三价稀土的协同萃取作用,顾翼东对HPZL体系的实验说明DBSO的协萃能力大于TBP;可是D.Dyrssen和J.H.Augustson等对HTTA体系的研究结果表明DBSO的协萃作用明显地弱于TBP。同时,Dyrssen的工作还说明在HTTA体系中DBSO和三价稀土形成的萃合物与TBP所形成的类型相同。有关TBP在水杨酸(H_2SaL)体系中对三价稀土的协同效应已有报导,并确认形成M(HSaL)_3(TBP)_2类型萃合物。为了进一步了解有机亚砜的协萃作用,本 相似文献
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测定了N503、TBP和TRPO萃取苯酚的平衡曲线。发现TBP和TRPO萃取平衡线可用Langmuir型方程表示,20℃时的萃取平衡常数分别为157和540。N503萃取苯酚的平衡线呈S形,因此低浓度时萃取脱酚比较困难。含TBP和TRPO的萃淋树脂吸附苯酚的平衡性能与萃取相似,其温度引起的变化和溶剂萃取完全相同,但同温度下的平衡常数略小。讨论并比较了不同萃取剂萃取和萃淋树脂吸附的性能,认为萃淋树脂有其优越性。 相似文献
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QING Hai-ruo 《成都理工大学学报(自然科学版)》2004,31(6)
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. 相似文献
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YUJia-shun HEZhen-hua 《成都理工大学学报(自然科学版)》2004,31(6):694-698
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod… 相似文献
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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. 相似文献
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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 总被引:9,自引:1,他引:9
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。 相似文献
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Yan Yun’an 《华南师范大学学报(自然科学版)》2014,(6):136-137
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 相似文献
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Yuriko Aoki 《华南师范大学学报(自然科学版)》2014,46(6):135-135
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 相似文献
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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. 相似文献
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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). 相似文献
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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. 相似文献