Surface Properties of Cu Doped La-Ni Intermetallic Compounds

A series of Cu-doped La-Ni intermetallic compounds(LaN5-xCux, x = 0-4) was studied. The bulk structure and surface composition of the samples were detected before and after they were used as catalyst for nitrobenzene hydrogennation. The catalytic properties of the intermetallic compounds depend on the surface region composition, especially on the valence of the metal ions.

Quantitative evaluation of model consistency evolution in compositional service-oriented simulation using a connected hyper-digraph

Appropriate maintenance technologies that facilitate model consistency in distributed simulation systems are relevant but generally unavailable.To resolve this problem,we analyze the main factors that cause model inconsistency.The analysis methods used for traditional distributed simulations are mostly empirical and qualitative,and disregard the dynamic characteristics of factor evolution in model operational running.Furthermore,distributed simulation applications(DSAs)are rapidly evolving in terms of large-scale,distributed,service-oriented,compositional,and dynamic features.Such developments present difficulty in the use of traditional analysis methods in DSAs,for the analysis of factorial effects on simulation models.To solve these problems,we construct a dynamic evolution mechanism of model consistency,called the connected model hyper-digraph(CMH).CMH is developed using formal methods that accurately specify the evolutional processes and activities of models(i.e.,self-evolution,interoperability,compositionality,and authenticity).We also develop an algorithm of model consistency evolution(AMCE)based on CMH to quantitatively and dynamically evaluate influencing factors.Experimental results demonstrate that non-combination(33.7%on average)is the most influential factor,non-single-directed understanding(26.6%)is the second most influential,and non-double-directed understanding(5.0%)is the least influential.Unlike previous analysis methods,AMCE provides good feasibility and effectiveness.This research can serve as guidance for designers of consistency maintenance technologies toward achieving a high level of consistency in future DSAs.

Runtime support for type-safe and context-based behavior adaptation

Context-awareness is becoming critical for mo- bile and ubiquitous computing, where the application needs dynamically adapt its behavior to its execution environment. Context-oriented programming （COP） languages support dy- namic behavior adaptation, however, they do not support dy- namic layer addition. As a result, they provide little support for the runtime adaptation of application behavior in case that unpredictable execution environments are encountered. Furthermore, block-structured constructs for layer activation hardly support fine-grain adaptation and separate changes of contexts and execution of context-specific methods with dif- ficulty. In this paper, we propose a virtual machine （VM）- centric approach to address these issues. It incorporates ob- ject composition and delegation into the VM to implement layer activation, and extends existing VM services to sup- port dynamic layer addition. To ensure that our approach preserves the type safety properties of the program, we de- velop a calculus built on featherweight Java （FJ） to describe the approach, focus on type-checking issues, and prove type soundness of the calculus. We also present the implementa- tion and evaluation of our approach. The evaluation demon- strates that our approach has advantages over the compiler- based approach proposed by JCOP.

IF一阶逻辑视域下的量词与量化观念

IF一阶逻辑及博弈论语义学比标准一阶逻辑及塔斯基语义学更加充分、更加动态和更加精细地刻画了量词之间的依赖关系。把量词视为一类选择函数,利用玩家之间的信息依赖来建模量词之间的函数依赖,严格区分约束辖域与优先辖域,为我们提供了一套全新的量化理论。但是,IF一阶逻辑及博弈论语义学并不意味着必须放弃组合原则。只要适当改变博弈方式,采用团队赋值博弈,那么组合原则又可得以复活。所以,应该正确看待IF一阶逻辑带来的“变革”与挑战。