https://is.muni.cz/el/1431/podzim2006/C7780/um/Read/2711172/SAM_str_grwth_ProgSurfSci00_151.pdf

Structure and growth of self-assembling monolayers

Many real dynamic systems are better characterized using a non-integer order dynamic model based on fractional calculus or, differentiation or integration of non-integer order. Traditional calculus is based on integer order differentiation and integration. The concept of fractional calculus has tremendous potential to change the way we see, model, and control the nature around us. Denying fractional derivatives is like saying that zero, fractional, or irrational numbers do not exist. In this paper, we offer a tutorial on fractional calculus in controls. Basic definitions of fractional calculus, fractional order dynamic systems and controls are presented first. Then, fractional order PID controllers are introduced which may make fractional order controllers ubiquitous in industry. Additionally, several typical known fractional order controllers are introduced and commented. Numerical methods for simulating fractional order systems are given in detail so that a beginner can get started quickly. Discretization techniques for fractional order operators are introduced in some details too. Both digital and analog realization methods of fractional order operators are introduced. Finally, remarks on future research efforts in fractional order control are given.

/pdf/fractional-order-control-a-tutorial-4zjusf99pg.pdf

Fractional order control - A tutorial

Dicarbonyl (η5-cyclopentadienyl)cobalt functions as a matrix on which a variety of unsaturated organic substrates undergo mutual bond formation. In this way α,ω-diynes cocyclize with monoalkynes to give annelated benzenes, while o-diethynylbenzenes furnish biphenylenes, and α,ω-enynes lead to the formation of complexed bi-and tricyclic dienes. Nitriles cocyclize with two alkynyl groups to give pyridines and other heterocycles, isocyanates allow access to annelated 2-pyridones, and incorporation of carbon monoxide provides complexed cyclopentadienones. In many cases remarkable chemo-, regio-, and stereoselectivity are observed, partially facilitated by use of the trimethylsilyl substituent as a controlling group. The scope and level of maturity of the method are demonstrated by the synthesis of a series of hitherto inaccessible, novel, and theoretically interesting molecules, and by its utilization in several unique approaches to a variety of natural products, e.g. protoberberines, steroids, vitamin B6, and camptothecin.

/pdf/cobalt-mediated-2-2-2-cycloadditions-a-maturing-synthetic-2ersrj0gwi.pdf

Cobalt‐Mediated [2 + 2 + 2]‐Cycloadditions: A Maturing Synthetic Strategy [New Synthetic Methods (43)]

A recent article published in this magazine has labeled fractional-order continuous-time systems as the "21st century systems". Indeed, this emerging research area is slowly gaining momentum among electrical engineers while its deeply rooted mathematical concepts also slowly migrate to various engineering disciplines. A very important aspect of research in fractional-order circuits and systems is that it is an interdisciplinary subject. Specifically, it is an area where biochemistry, medicine and electrical engineering over-lap giving rise to many new potential applications. This article aims to provide an overview of the current status of research in this area, highlighting specific problems which need to be addressed particularly by electrical engineers.

Fractional-order circuits and systems: An emerging interdisciplinary research area

Studies on fractional order differentiators and integrators: A survey

The third-order optical nonlinearity of metal(dmit)2 was investigated with femtosecond optical Kerr effect at 830 nm wavelength. The nonresonant second-order hyperpolarizability for the didodecyldimethylammonium–Au(dmit)2 (2C12–Au) molecule was estimated to be as large as 2.2×10−32 esu.

Third-order nonlinear optical properties of didodecyldimethylammonium-Au(dmit)(2)

Simulation of Fractal Immittance by Analog Circuits: An Approach to the Optimized Circuits

Self-assembled monolayers of terminally fluorinated alkanethiols, CF3(CH2)nSH with n = 9−15, and their nonfluorinated analogues, CH3(CH2)nSH with n = 9−15, were prepared by adsorption from solution onto evaporated gold. The monolayers were characterized by contact angle goniometry, ellipsometry, and X-ray photoelectron spectroscopy. The analyses indicate that the CF3-terminated alkanethiols generate terminally fluorinated monolayers that are well-ordered, particularly when the chain lengths consist of 12 or more carbon atoms. Comparison of CF3-terminated films to CH3-terminated films of similar length reveals that terminal fluorination of the surface leads to an overall decrease in the surface tension of the films. This decrease arises from a relatively large decrease in the dispersive component of the surface tension upon the introduction of fluorine. Surprisingly, terminal fluorination also leads to a small but significant increase in the nondispersive component(s) of the surface tension. The origin of ...

Wettabilities of Self-Assembled Monolayers Generated from CF3-Terminated Alkanethiols on Gold

http://lee.chem.uh.edu/1999/JFluorineChemv93p107.pdf

Terminally perfluorinated long-chain alkanethiols

Electronic transport measurements are reported for Langmuir-Blodgett (LB) films of tridecylmethylammonium-Au(dmit)2 for 300-4 K. The conductivity after electrochemical oxidation is 30-50 S/cm at room temperature, increases with decreasing temperature, and begins decrease at about 200 K. The conductivity at lower temperatures is explained by two-dimensional variable range hopping (2D VRH). The thermoelectric power (S) is positive and well fitted by a linear combination of the temperature dependence of 2D VRH (Sv\proptT1/3) and that of metal (Sm\proptT). These results can be explained by a model in which highly conductive metallic regions are separated by thin weakly conductive regions. The UV/visible absorption spectra and the X-ray diffraction patterns indicate that a large structural change occurs accompanied by electrochemical oxidation.

Yasuhiro F. Miura

Papers

Third-order nonlinear optical properties of didodecyldimethylammonium-Au(dmit)(2)

Simulation of Fractal Immittance by Analog Circuits: An Approach to the Optimized Circuits

Wettabilities of Self-Assembled Monolayers Generated from CF3-Terminated Alkanethiols on Gold

Terminally perfluorinated long-chain alkanethiols

Structure and Electronic Transport of Highly Conductive Langmuir-Blodgett Films of Tridecylmethylammonium-Au(dmit)2