Polarization of low-lying excitonic bands in finite-size semiconducting single-walled carbon nanotubes (SWNTs) is studied by using quantum-chemical methodologies. Our calculations elucidate properties of cross-polarized excitons, which lead to the transverse optical absorption of nanotubes and presumably couple to intermediate-frequency modes recently observed in resonance Raman excitation spec...

This paper presents a review of the pulse tube refrigerator from its inception in the mid-1960s up to the present. Various factors are discussed which brought it from a laboratory curiosity to the point where it is now the most efficient of all cryocoolers and reliable enough to be used on space missions. Carnot efficiencies as high as about 20% at 80 K and temperatures as low as 2 K have been ...

Pollen deposition and pollen tube formation are key components of angiosperm reproduction but intraspecific variation in these has rarely been quantified. Documenting and partitioning (populations, plants and flowers) natural variation in these two aspects of plant reproduction can help uncover spatial mosaics of reproductive success and underlying causes. In this study, we assess variation in ...

In Drosophila, the Toll receptor signaling pathway is required for embryonic dorso-ventral patterning and at later developmental stages for innate immune responses. It is thought that dimerization of the receptor by binding of the ligand spätzle causes the formation of a postreceptor activation complex at the cytoplasmic surface of the membrane. Two components of this complex are the adaptor tu...

The design of an iodine working medium storage and supply system is one the key technologies for electrical propulsion medium. Solid sublimates into a gaseous state in tank, transported to thruster through flow control components such as proportional valve or throttle tube. However, has corrosive properties poor thermal conductivity, which can easily cause condensation tube valve, affecting acc...

BACKGROUND One of the most effective ways for distal movement of molars to treat Class II malocclusion is using extraoral force through a headgear device. The purpose of this study was the comparison of stress distribution in maxillary first molar periodontium using straight pull headgear in vertical and horizontal tubes through finite element method. MATERIALS AND METHODS Based on the real g...

The non-covalent functionalization of carbon nanotubes with spiropyran molecules, serving as optically addressable dipole switches, is reported. Two kinds of pyrene-spiropyran-based dyads with spacers of different lengths resulting in different switch-tube distances were investigated. While both surfactants were able to form stable carbon nanotube suspensions, the different distances between th...

Examples with zero-sum linear differential games of fixed terminal time and a convex terminal payoff function depending on two components of the phase vector are considered. Such games can have an indifferent zone with constant value function. The level set of the value function associated with the indifferent zone is called the “critical” tube. In the selected examples, the critical tube and t...

Within the paper we present real remote experiment “Free fall of a body in a glass tube”. The experiment is based on the movement of a permanent magnet in a glass tube with induction pick up coils for position measurement. The paper also shows the possibilities of implementation of this experiment to direct educational process as a part of new strategy of education – Integrated eLearning (INTe-...

In this paper, a transcritical carbon dioxide power generation system based on vortex tube is studied, which has the advantage of self-condensation dioxide. The thermodynamic performance was investigated by establishing mathematical model. results showed that under fundamental working conditions, could output net 271.72 kW, and thermal efficiency as well exergy reach 7.38% 27.09%, respectively....