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81.
《分离科学与技术》2012,47(8):1113-1118
The selective transport of copper(II), zinc(II), cobalt(II), and nickel(II) ions from nitrate solutions across polymer inclusion membranes (PIMs), which consist of cellulose triacetate as polymeric support, o-nitrophenyl pentyl ether as plasticizer, and 1-alkylimidazole (alkyl from hexyl- to decyl) as ion carrier was reported. PIM was characterized by using atomic force microscopy (AFM) technique. The results show that Cu(II) can be separated very effectively from other transition metal cations as Zn(II), Co(II), and Ni(II) (at a concentration of 10?3 mol/dm3 each). Alkyl substituents at position 1 of the imidazole ring have been found to affect the hydrophobic properties and initial flux of the transported metal ions. The efficiency of separation of metal ions by 1-alkylimidazole followed the sequence: Cu(II) > Zn(II) > Co(II) > Ni(II). The highest selectivity coefficient for Cu(II) was found with 1-hexylimidazole and its 1 mol/dm3 solution in PIM. Separation of the ions was more effective for the nitrates(V) than for chlorides.  相似文献   
82.
《分离科学与技术》2012,47(9):1383-1389
The facilitated transport of Cu(II) ions from different aqueous nitrate source phases (c Me = 0.001 M, pH = 6.0) across supported (SLMs) and polymer inclusion membranes (PIMs) doped with 1-hexyl-2-methylimidazole as ion carrier was reported. The membrane is characterized by means of atomic force microscopy (AFM). The results show that Cu2+ can be separated very effectively from other transition metal cations as Zn2+, Co2+, and Ni2+ from different equimolar mixtures of these ions. The highest initial fluxes of Cu(II) were found for PIM, while lower values were observed for SLM. However, after taking into account the morphology of the membranes (porosity, tortuosity), the values of the initial flux of Cu(II) transport across PIM is less than that across SLM. The recovery factor of Cu2+ ions during transport across PIM from different mixtures of cations is above 91% after 24 hrs and above 76% during transport across SLM. Also, the stability of PIM and SLM doped with 1-hexyl-2-methylimidazole was confirmed in replicate experiments.  相似文献   
83.
模型驱动构架中基于元模型的设计模式单元的组建和转换   总被引:1,自引:0,他引:1  
杨长春  赵子艺  孙婧 《计算机应用》2010,30(9):2354-2357
设计模式种类繁多而且在不断变化,要在模型驱动构架(MDA)下真正做到从思想和实现上均能应用设计模式,需要解决其实例化后的模式消失问题,保证模式的独立性,并且可以将这个过程适用到多种设计模式中去。针对以上两个问题,采取一种基于元模型的设计模式单元的建模方法,从元模型层面划分基本操作为不可分的原子,组合出完整的不包含业务逻辑部分的设计模式单元元模型,使多种模式单元元模型的组合构建和业务、模式逻辑相分离在经过一次转换过程后同时实现。  相似文献   
84.
移动个人信息管理系统是运行在掌上电脑、智能手机等移动设备上的个人信息管理系统。为实现其对各种类型的个人信息的强大管理功能,必须要有一个适宜的底层存储方案作为保障。本文基于COM的结构化存储机制和实验室自主研发的嵌入式移动数据库管理系统SwiftDB的数据管理功能,提出了一种信息项存储方案,能够解决个人信息项种类繁多和移动设备上资源有限等系统存储难点,以较小的代价和较快的存取速度实现用户对信息项的访问操作。  相似文献   
85.
86.
文章指出传统PIM-SM组播存在的问题,介绍SSM源特定组播技术的优越性、SSM的实现过程及安全SSM应考虑的两个方面。  相似文献   
87.
Web development is moving towards model-driven processes whose goal is the development of Web applications at a higher level of abstraction based on models and model transformations. This brings new opportunities to the Web project manager to make early estimates of the size and the effort required to produce Web applications based on their conceptual models. In the last few years, several studies for size and effort estimation have been performed. However, there are no studies regarding effort estimation in model-driven Web development. In this paper, we present the validation of a model-based size measure (OO-HFP) for Web effort estimation in the context of a model-driven Web development method. The validation is performed by comparing the prediction accuracy that OO-HFP provides with the accuracy provided by the standard function point analysis (FPA) method. The results of the study (using industrial data gathered from 31 Web projects) show that the effort estimates obtained for projects that are sized using OO-HFP are more accurate than the effort estimates obtained using the standard FPA method. This suggests that by following a model-driven development approach, the size measure obtained at the conceptual model of a Web application can be considered a suitable predictor of effort.  相似文献   
88.
遥传技术是随钻测量(MWD,measurement while drilling)系统中的一项关键技术,目前大多数MWD系统均采用泥浆脉冲方式进行数据传输.随着井深的增加,单纯的脉冲调制的传输性能会快速恶化.提出了一种联合卷积编码与脉冲间隔调制,构造出一种网格编码脉冲间隔调制(TC-PIM)方法.TC-PIM最大化调制输出序列之间的最小时间距离,从而获得显著的编码增益.TC-PIM可以用于随钻测量系统,以提高泥浆脉冲遥传系统的传输距离.  相似文献   
89.
Various agent-oriented methodologies and metamodels exist to design and develop multiagent systems (MAS) in an abstract manner. Frequently, these frameworks specialise on particular parts of the MAS and only few works have been invested to derive a common standardisation. This limits the impact of agent-related systems in commercial applications. In this paper, we present a metamodel for agent systems that abstracts from existing agent-oriented methodologies, programming languages, and platforms and could thus be considered as platform-independent. This metamodel defines the abstract syntax of a proposed domain-specific modelling language for MAS that is currently under development and provides furthermore the base to generate code out of the generated designs. This is done by applying the principles of model-driven development (MDD) and providing two model transformations that allow transforming the generated models into textual code that can be executed with JACK and JADE.  相似文献   
90.
研究基于多协议标签交换(MPLS)的IPv6组播技术。阐述基于接收方数据流驱动的标签(label)分配机制,设计出一种基于MPLS域的标签交换路径(Label Switched Path,LSP)的组播树构建方案,并给出了入口和出口LER(Label Switching Router)中的标签复制和转发算法。根据MPLS域的标签标记网络层协议,在IPv6网络环境下实验验证标签以及组播包复制和转发算法。  相似文献   
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