نتایج جستجو برای: catalyst

تعداد نتایج: 44027  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1392

a novel acrylic acid-functionalized fe3o4 magnetic nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperacid in chemical transformations. the structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (tem), thermogravimetric analysis (tga), and ft-ir...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this thesis, we exploit a simple and suitable method for immobilization of copper(ii) complex of 4?-phenyl-terpyridine on activated multi-walled carbon nanotubes [amwcnts-o-cu(ii)-phtpy]. this nanostructure was characterized by various physico-chemical techniques. to ensure the efficiency and fidelity of copper species, the implementation of three-component strategies in click-chemistry all...

2005
Mike Klaas

Summarization of electronic discussion fora is a unique challenge; techniques that work startlingly well on monolithic documents tend to fare poorly in this informal setting. Additionally, conventional techniques ignore much of the structures that have the potential to serve as valuable features in the summarization task. We present several novel examples of such features, including the catalys...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...

2017
Frédéric Hapiot Eric Monflier

Aqueous biphasic catalysis is a convenient approach to convert organic, partially soluble molecules in water. However, converting more hydrophobic substrates is much more challenging as their solubility in water is extremely low. During the past ten years, substantial progress has been made towards improving the contact between hydrophobic substrates and a hydrophilic transition-metal catalyst....

1997
Ana Jurema Maureen O'Rourke

This paper argues that Information Technology (IT) needs to be demystified, through critical consciousness, for educators to focus on IT as a means to enhance learning. It goes on to define the technical, sociohistorical and political-ideological levels of IT and to identify four theoretical constructs: tutorial, machine-as-human, tool kit and catalyst. Pervading these constructs is the underst...

1996
Alison M. Etheridge Klaus Fleischmann

The super-Brownian motion X % in a super-Brownian medium % constructed in DF96a] is known to be persistent (no loss of expected mass in the longtime behaviour) in dimensions one ((DF96a]) and three ((DF96b]). Here we ll the gap in showing that persistence holds also in the critical dimension two. The key to this result is that in any dimension (d 3); given the catalyst, the variance of the proc...

2002
Ikujiro Nonaka Martin Kenney

This paper argues that innovation can be best understood as an information process which is then concretized as a product that meets demand. Two very different firms, Canon Inc. and Apple Computer Inc., are used as case study illustrations. Innovation does not proceed through logical deduction, but rather is furthered by the use of metaphors and analogies. The bureaucratic and staid structures ...

2002
OSKAR BAUDISCH DAVID DAVIDSON

The observation of Manchot? that sodium pentacyano-ammineferroate2 I absorbs oxygen has led Baudisch and his coworkers3 to study the catalytic action of this salt, as well as of its water analogue II, in the oxidation of pyrimidines and purines. The present authors have previously reported in this journal4 on the nature of the oxidation products obtained. In the present paper the problem is con...

2004
John A. List Daniel L. Millimet

Assumptions of individual rationality and preference stability provide the foundation for a convenient and tractable modeling approach. While both of these assumptions have come under scrutiny in distinct literatures, the two lines of research remain disjointed. This study begins by explicitly linking the two literatures while providing insights into perhaps the central issue facing behavioral ...

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