Recent progress in pillar[n]arene-based thin films on chemical sensor applications

Journal of Inclusion Phenomena and Macrocyclic Chemistry - Pillar[n]arene is one of the most favorited supramolecular materials that possess a special chiral structure. The major property of...     

One-Parameter Plane Hyperbolic Motions

Müller [3], in the Euclidean plane , introduced the one parameter planar motions and obtained the relation between absolute, relative, sliding velocities (and accelerations). Also, Müller [11] provided the relation between the velocities (in the sense of Complex) under the one parameter motions in the Complex plane . Ergin [7] considering the Lorentzian plane , instead of the Euclidean plane , and introduced the one-parameter planar motion in the Lorentzian plane and also gave the relations between both the velocities and accelerations. In analogy with the Complex numbers, a system of hyperbolic numbers can be introduced: . Complex numbers are related to the Euclidean geometry, the hyperbolic system of numbers are related to the pseudo-Euclidean plane geometry (space-time geometry), [5,15]. In this paper, in analogy with Complex motions as given by Müller [11], one parameter motions in the hyperbolic plane are defined. Also the relations between absolute, relative, sliding velocities (and accelerations) and pole curves are discussed.      

Roughness induced forced convective laminar-transitional micropipe flow: energy and exergy analysis

Variable fluid property continuity, Navier–Stokes and energy equations are solved for roughness induced forced convective laminar-transitional flow in a micropipe. Influences of Reynolds number, heat flux and surface roughness, on the momentum-energy transport mechanisms and second-law of thermodynamics, are investigated for the ranges of Re = 1–2,000, Q = 5–100 W/m² and ε = 1–50 μm. Numerical investigations put forward that surface roughness accelerates transition with flatter velocity profiles and increased intermittency values (γ); such that a high roughness of ε = 50 μm resulted in transitional character at Re _tra = 450 with γ = 0.136. Normalized friction coefficient (C _f^*) values showed augmentation with Re, as the evaluated C _f^* are 1.006, 1.028 and 1.088 for Re = 100, 500 and 1,500, respectively, at ε = 1 μm, the corresponding values rise to C _f^* = 1.021, 1.116 and 1.350 at ε = 50 μm. Heat transfer rates are also recorded to rise with Re and ε; moreover the growing influence of ε on Nusselt number with Re is determined by the Nu _ε=50 μm/Nu _ε=1 μm ratios of 1.086, 1.168 and 1.259 at Re = 500, 1,000 and 1,500. Thermal volumetric entropy generation values decrease with Re and ε in heating; however the contrary is recorded for frictional volumetric entropy generation data, where the augmentations in are more considerable when compared with the decrease rates of      

一个解剖基人体下肢的生物动力模型--第二部分: 数值结果

表述人体下肢生物动力模型的数值技术、数值结果并将其与文献进行比较.模型显示:当人体下肢小腿受冲击外载荷作用时,在膝关节处所产生的4个主要韧带张力以及膝关节处的咬合接触力,在大腿固定不动(或运动受到约束)的情况下,要远大于大腿未受约束的情形.这与医学常识是吻合的.     

Cp2TiCl2-catalyzed reaction of symmetrical alkynes with α,ω-dicarboxylic acid esters and ЕtAlCl2: An original pathway to С5-С6 cyclic ketones and tetrasubstituted furans

An original method for the synthesis of С₅-С₆ cyclic ketones and tetrasubstituted furans was developed based on the Cp₂TiCl₂-catalyzed reaction of symmetrical alkynes and α,ω-dicarboxylates in the presence of Mg and ЕtAlCl₂. The length of the hydrocarbon chain between carboxyl groups in a,ω-dicarboxylic acid esters affects the chemoselectivity of the reaction. The formation of 2-alkylidene and 2-alkenyl cyclopent(hex)an-1-ones occurred in the reaction with esters of glutaric and adipic acids. α,ω-Dicarboxylic acid esters with more than four methylene units between carboxyl groups gave rise to substituted furans. Stereochemistry of 2-alkenyl cyclopent(hex)an-1-ones was determined based on the analysis of experimental and theoretical data obtained from DFT calculations.     

Triethylamin-mediated addition of 2-aminoethanethiol hydrochloride to chalcones: Synthesis of 3-(2-aminoethylthio)-1-(aryl)-3-(thiophen-2-yl) propan-1-ones and 5,7-diaryl-2,3,6, 7-tetrahydro-1,4-thiazepines

The triethylamin-mediated addition of 2-aminoethanethiol hydrochloride to chalcone analogs was investigated. This addition, bearing a 2-thienyl group at the 3-position, gave the only addition adduct at room temperature in 3 h, whereas the chalcones bearing the 2-furyl group at the 1-position gave an addition-cyclization product (1, 4-thiazepine) in the same conditions. The effect of the groups to the reaction was investigated by changing the 1- and 3-position groups. The chalcones bearing the 2-thienyl group at the 1-position and the others afforded the mixture of products in different ratio at rt for 0.5–24 h. Moreover, the addition–cyclization products (1,4-thiazepine) were obtained under reflux conditions in 36 h. The structures of the synthesized compounds were elucidated by ¹H NMR, ¹³C NMR, infrared, and elemental analysis.     

Quasi-coherent states for a photon in time varying dielectric media

In this study, we derive the quasi-coherent states for a photon in a medium with time varying dielectric permittivity ${?}_0{e}^{\eta t}$. We introduce a new kind of holomorphic coordinates and solve the Schrödinger equation for a harmonic oscillator with the time dependent parameters by reducing it to the Riccati equation for which the nonstationary solution gives the squeezed states of a photon with non-minimum uncertainties. We also derive the quasi-coherent states and discrete, nonstationary quantum states in the configuration space of a photon.     

Radial Equations for the Relativistic Two-Fermion Problem with the Most General Electric and Magnetic Potentials

The 16 × 16 spinor equations of two fermions interacting with their charges and anomalous magnetic moments have been separated first covariantly into center of mass and relative coordinates, then completely into angular and radial parts. The 16 radial equations reduce by a symmetry into two sets of 8 equations, four of which are algebraic. The final result is a set of four first order equations or two coupled second order equations.