Odnos anomalne transmisije i negativnog gašenja u Braggovom slučaju

The relationship between the anomalous transmission and the negative extintion in the symmetrical Bragg case near the absorption edge is studied in detail. The negative extinction results from the anomalous transmission and takes the largest value when the diffraction is induced only by the imaginary part of the atomic scattering factor near the absorption edge. The appearance of the negative extinction also depends on temperature, which can be used for the identification of the theoretical model for calculating the Debye-Waller factor.Podrobno se razmatra odnos anomalne transmisije i negativnog gašenja za simetričan Braggov slucaj. Negativno gašenje je posljedica anomalne transmisije i najveće je kada je difrakcija uzrokovana samim imaginarnim dijelom atomskog faktora raspršenja u blizini apsorpcijskog ruba. Pojava negativnog gašenja ovisi također o temperaturi, što se može primijeniti za prepoznavanje teorijskog modela pri izračunavanju Debye-Wallerovog faktora

Odnos anomalne transmisije i negativnog gašenja u Braggovom slučaju

The relationship between the anomalous transmission and the negative extintion in the symmetrical Bragg case near the absorption edge is studied in detail. The negative extinction results from the anomalous transmission and takes the largest value when the diffraction is induced only by the imaginary part of the atomic scattering factor near the absorption edge. The appearance of the negative extinction also depends on temperature, which can be used for the identification of the theoretical model for calculating the Debye-Waller factor.Podrobno se razmatra odnos anomalne transmisije i negativnog gašenja za simetričan Braggov slucaj. Negativno gašenje je posljedica anomalne transmisije i najveće je kada je difrakcija uzrokovana samim imaginarnim dijelom atomskog faktora raspršenja u blizini apsorpcijskog ruba. Pojava negativnog gašenja ovisi također o temperaturi, što se može primijeniti za prepoznavanje teorijskog modela pri izračunavanju Debye-Wallerovog faktora

Highly Sensitive Fluorescence Probe Based on Functional SBA-15 for Selective Detection of Hg2+

An inorganic–organic hybrid fluorescence chemosensor (DA/SBA-15) was prepared by covalent immobilization of a dansylamide derivative into the channels of mesoporous silica material SBA-15 via (3-aminopropyl)triethoxysilane (APTES) groups. The primary hexagonally ordered mesoporous structure of SBA-15 was preserved after the grafting procedure. Fluorescence characterization shows that the obtained inorganic–organic hybrid composite is highly selective and sensitive to Hg2+ detection, suggesting the possibility for real-time qualitative or quantitative detection of Hg2+ and the convenience for potential application in toxicology and environmental science

Model Checking Dynamic UML Consistency

Abstract. Being the de facto industry standard of software modeling, UML is well accepted and extensively used. However, using different diagrams to model different aspects of a system brings the risk of inconsistency among diagrams. In this paper, we investigate an approach to check the consistency between the sequence diagrams and statechart diagrams using the SPIN model checker. To deal with the hierarchy structure of statechart diagrams, we propose a formalism called Split Automata, a variant of automata, which is helpful to bridge the statechart diagrams to SPIN efficiently. Compared with the existing work on model checking UML which do not have formal verification for their translation from UML to the model checker, we formally define the semantics and prove that the automatically translated model (i.e. Split Automata) does simulate the UML model. Via this way, we can guarantee that the translated models does represent the original models with respect to the checking motivation

Towards the formal model and verification of web service choreography description language

Abstract. The Web Services Choreography Description Language (WS-CDL) is a W3C specification for the description of peer-to-peer collaborations of participants from a global viewpoint. For the rigorous development and tools support for the language, the formal semantics of WS-CDL is worth investigating. This paper proposes a small language CDL as a formal model of the simplified WS-CDL, which includes important concepts related to participant roles and collaborations among them in a choreography. The formal operational semantics of CDL is given. Based on the formal model, we discuss further: 1) project a given choreography to orchestration views, which provides a basis for the implementation of the choreography by code generation; 2) translate WS-CDL to the input language of the model-checker SPIN, which allows us to automatically verify the correctness of a given choreography. An automatic translator has been implemented.

A Type System for the Relational Calculus of Object Systems

Abstract. Being a successful technique in software practice, Object Orientation (OO) is a hot topic in academic research fields. Within many formalisms, rCOS, a refinement calculus of object-oriented systems based on Unifying Theories of Programming (UTP), has been proven a promising one in the sense of its applications on incremental software constructions, the formal use and checking for UML based develop processes, etc. However, equipped with a semantics including both static and dynamic properties, rCOS is not designed for static checking. We believe introducing static checking will numerously extend the power of rCOS. In this paper, as a first step, we develop a type system for rCOS with type safety theorems. To make the theoretical results of this paper convincible and easy to be understood, we follow the traditional approaches of type systems construction. That is, we use an operational semantics as the basic explanation of rCOS language in spite of the fact that rCOS is originally developed in a denotational framework. Keywords: Type system, rCOS, Object-orientation, Operational semantics

Optimal Time–Jerk Trajectory Planning for Delta Parallel Robot Based on Improved Butterfly Optimization Algorithm

In this paper, a multi-objective integrated trajectory planning method based on an improved butterfly optimization algorithm (IBOA) is proposed, to improve the dynamic performance of the Delta parallel pickup robot in high-speed pick-and-place processes. The main objective of the present study is to improve dynamic positioning accuracy and running stability at high speeds and high accelerations. On the one hand, the intention is to ensure smooth motions using the trajectory planning method, and on the other hand to improve the picking efficiency. To this end, the pick-and-place trajectory of the robot is constructed by using NURBS curves in Cartesian space. Taking the time and jerk as the optimization objectives, a trajectory optimization method based on the improved butterfly optimization algorithm (IBOA) is proposed. The IBOA is based on the butterfly optimization algorithm (BOA); a circle chaotic sequence is introduced to replace the random initial population of the original BOA, and the fractional differential is used to improve the convergence speed of the BOA. Then, the problem of parallel segment deformation of the optimized trajectory is solved. Finally, a three-degrees-of-freedom Delta robot is used to evaluate the performance of the prosed algorithm. The obtained results show that, compared with other optimization algorithms, IBOA reduces the optimization time by 16.2%, and the maximum jerk is reduced by 87.6%. The results are better than the optimization results of other algorithms by 14.1% and 27.2%. The robot motion simulation results show that IBOA can effectively reduce the vibration acceleration of the end platform

Software Technology A Type System for the Relational Calculus of Object Systems

in July 1992. UNU-IIST is jointly funded by the Governor of Macau and the governments of the People’s Republic of China and Portugal through a contribution to the UNU Endownment Fund. As well as providing twothirds of the endownment fund, the Macau authorities also supply UNU-IIST with its office premises and furniture and subsidise fellow accommodation. The mission of UNU-IIST is to assist developing countries in the application and development of software technology. UNU-IIST contributes through its programmatic activities: 1. Advanced development projects, in which software techniques supported by tools are applied, 2. Research projects, in which new techniques for software development are investigated, 3. Curriculum development projects, in which courses of software technology for universities in developing countries are developed, 4. University development projects, which complement the curriculum development projects by aiming to strengthen all aspects of computer science teaching in universities in developing countries, 5. Schools and Courses, which typically teach advanced software development techniques, 6. Events, in which conferences and workshops are organised or supported by UNU-IIST, and 7. Dissemination, in which UNU-IIST regularly distributes to developing countries information on internationa

Towards the theoretical foundation of choreography

With the growth of interest on the web services, people pay increasinglyattention to the choreography, that is, to describe collaborations ofparticipants in accomplishing a common business goal from a globalviewpoint. In this paper, based on a simple choreography language and arole-oriented process language, we study some fundamental issues relatedto choreography, especially those related to implementation, includingsemantics, projection and natural projection, dominant role in choices anditerations, etc. We propose the concept of dominant role and somenovel languages structures related to it. The study reveals some cluesabout the language, the semantics, the specification and theimplementation of choreography.EI

model-checking of web services choreography

Web services choreography describes the global model of service interactions among a set of participants. In order to achieve a common business goal, the protocols of interaction must be correct. In this paper, we model interactions with recordings of st