Hoci najznámejšou technickou aplikáciou kvapalných kryštálov v dnešnej dobe sú kvapalno-kryštalické monitory, kvapalné kryštály sú viac než len ploché obrazovky, aj keď vďaka nim sa dostali do povedomia verejnosti. Výskum v oblasti kvapalných kryštálov však nabral nový smer. Svetový výskum sa odvracia od displejov a zameriava sa na nové možnosti ich využitia, a to na štúdium kompozitných systémov na báze kvapalných kryštálov nielen pre ich technické aplikácie, ale aj na ich využitie v biotechnológiách., Nowadays, the major technical application of liquid crystals is their widespread use in liquid crystal displays. However, even though flat screens have drawn these materials to the public attentions they are much more than just flat screens. Academic liquid crystal science has shown a clear trend of moving away from display research during the last few years. Currently, scientists focus on different topics such as for instance new possible uses in optics, nano-/micro-manipulation, novel composites and biotechnology. This article demonstrates such a development of composite systems containing magnetic nanoparticles in liquid crystalline matrices., Natália Tomašovičová., and Obsahuje bibliografii
Odpor mnoha magnetických materiálů výrazně závisí nejen na velikosti, nýbrž i na směru magnetizace. Průmyslově se tento jev využívá v senzorech citlivých na magnetické pole, mezi něž v nedávno minulé době patřila i velká část světové produkce čtecích hlav počítačových pevných disků. Teoretické modely této anizotropní magnetorezistence ovšem zatím zdaleka nedosáhly uspokojivé úrovně a shody s experimenty bez fitovacích parametrů se podaří dosáhnout jen výjimečně. Skupina takových poměrně úspěšných modelů se v posledních letech rozrostla o další položku - zředěný magnetický polovodič (Ga,Mn)As., Electric resistance of many magnetic materials depends significantly both on strength and direction of its magnetization. Magnetic field sensors belong to the typical industrial applications of this phenomenon and until recently these included also a major part of the world production of read heads in computer hard-drives. Theoretical models of this anisotropic magnetoresistance, however, have never reached a completely satisfactory level and so far it has been only rarely possible to achieve a decent agreement with experiments without any fit parameters. Few years ago, the family of such relatively successful models could welcome a new member that concerns a dilute magnetic semiconductor (Ga, Mn)As., Karel Výborný., and Obsahuje bibliografii
Let R be a prime ring of characteristic different from 2 and 3, Qr its right Martindale quotient ring, C its extended centroid, L a non-central Lie ideal of R and n ≥ 1 a fixed positive integer. Let α be an automorphism of the ring R. An additive map D: R → R is called an α-derivation (or a skew derivation) on R if D(xy) = D(x)y + α(x)D(y) for all x, y \in R. An additive mapping F: R → R is called a generalized α-derivation (or a generalized skew derivation) on R if there exists a skew derivation D on R such that F(xy) = F(x)y + α(x)D(y) for all x, y \in R. We prove that, if F is a nonzero generalized skew derivation of R such that F(x)×[F(x), x]n = 0 for any x \in L, then either there exists λ \in C such that F(x) = λx for all x \in R, or R\subset M_{2}\left ( C \right ) and there exist a \in Qr and λ \in C such that F(x) = ax + xa + λx for any x \in R., Vincenzo De Filippis., and Obsahuje seznam literatury
We introduce the concepts of an annihilator and a relative annihilator of a given subset of a BCK-algebra $\mathcal A$. We prove that annihilators of deductive systems of BCK-algebras are again deductive systems and moreover pseudocomplements in the lattice $\mathcal D (A)$ of all deductive systems on $\mathcal A$. Moreover, relative annihilators of $C\in \mathcal D (A)$ with respect to $B \in \mathcal D (A)$ are introduced and serve as relative pseudocomplements of $C$ w.r.t. $B$ in $\mathcal D (A)$.
The concepts of an annihilator and a relative annihilator in an autometrized $l$-algebra are introduced. It is shown that every relative annihilator in a normal autometrized $l$-algebra $\mathcal {A}$ is an ideal of $\mathcal {A}$ and every principal ideal of $\mathcal {A}$ is an annihilator of $\mathcal {A}$. The set of all annihilators of $\mathcal {A}$ forms a complete lattice. The concept of an $I$-polar is introduced for every ideal $I$ of $\mathcal {A}$. The set of all $I$-polars is a complete lattice which becomes a two-element chain provided $I$ is prime. The $I$-polars are characterized as pseudocomplements in the lattice of all ideals of $\mathcal {A}$ containing $I$.