Degradation of organic light-emitting diodes based on different-ligand complexes of terbium (III) salicylate and 2-phenoxybenzoate

Degradation (D) of organic light-emitting diodes (OLEDs) based on new different-ligand complexes of terbium salicylate (Tb(Sal)₃(TPPO)₂) and 2-phenoxybenzoate (Tb(pobz)₃(TPPO)₂) with triphenyl phosphinoxide (TPPO) was studied. Initial reversible D is associated with charge carrier trap filling. A temperature increase, applied stress relief, and short-term irradiation with UV light lead to trapped charge carrier release and electroluminescence (EL) intensity recovery. During strong heating, irreversible D is observed after the recovery; this D requires in addition an electric field (EF). Intense UV light causes D without EF. The use of ac bias voltage eliminates reversible D, and sealing retards irreversible long-term D.     

Ion Mobility in Triple Sodium Molybdates and Tungstates with a NASICON Structure

Journal of Experimental and Theoretical Physics - Research data for the diffusion mechanisms of Na+ ions in Na1 – xMg1 – xAl1 + x(XO4)3 (X = Mo, W) compounds with the NASICON-type...     

The Possibility of Forming Two-Lobe Vortex Light Fields Using a Modified Liquid-Crystal Focusator

Optics and Spectroscopy - The possibilities of forming light fields with intensity distribution in the form of two maxima rotating during propagation using a liquid-crystal modal device are...     

The interference enhancement of light polarization conversion from structures with a quantum well

The optical activity of crystals leads to the occurrence of ellipticity at the reflection of light which is linearly polarized in the interface plane or normally to it. The effect experimentally discovered in the investigated structures with quantum wells is due to a spin-orbit interaction and birefringence. The qualitative dependence of the effect on the change in the orientation of the linear polarization of the incident light has been revealed. A sharp increase in the degree of the polarization conversion in a narrow range of incidence angles for light polarized in the incidence plane has been detected. The latter is due to the influence of the interference of the reflected wave on the structure thickness.     

Structural Features and Mutual Influence of the Layers in PZT–LNO–SiOx–Si and PZT–LNO–Si Compositions

Crystallography Reports - The phase composition and specific features of the microstructures of layers in the Pb(Zr0.52Ti0.48)O3–LaNiO3–Si and...     

Phase formation in the Ag<Subscript>2</Subscript>MoO<Subscript>4</Subscript>-MgMoO<Subscript>4</Subscript>-Al<Subscript>2</Subscript>(MoO<Subscript>4</Subscript>)<Subscript>3</Subscript> system

The subsolidus region of the Ag₂MoO₄-MgMoO₄-Al₂(MoO₄)₃ ternary salt system has been studied by X-ray phase analysis. The formation of new compounds Ag_{1 ? x} Mg_{1 ? x} Al_{1 + x} (MoO₄)₃ (0 ≤ x ≤ 0.4) and AgMg₃Al(MoO₄)₅ has been determined. The Ag_{1 ? x} Mg_{1 ? x} Al_{1 + x} (MoO₄)₃ variable-composition phase is related to the NASICON type structure (space group R \(\bar 3\) c). AgMg₃Al(MoO₄)₅ is isostructural to sodium magnesium indium molybdate of the same formula unit and crystallizes in triclinic system (space group P \(\bar 1\), Z = 2) with the following unit cell parameters: a = 9.295(7) Å, b = 17.619(2) Å, c = 6.8570(7) Å, α = 87.420(9)°, β = 101.109(9)°, γ = 91.847(9)°. The compounds Ag_{1 ? x} Mg_{1 ? x} Al_{1 + x} (MoO₄)₃ and AgMg₃Al(MoO₄)₅ are thermally stable up to 790 and 820°C, respectively.     

Phase formation in the system involving silver, magnesium, and indium molybdates

The subsolidus region of the Ag₂MoO₄-MgMoO₄-In₂(MoO₄)₃ ternary salt system has been studied by X-ray powder diffraction. The formation of new compounds Ag_{1 ? x} Mg_{1 ? x} In_{1 + x} (MoO₄)₃ (0 ≤ x ≤ 0.6) and AgMg₃In(MoO₄)₅ has been established. The unit cell parameters of solid-solution samples have been determined. The Ag_{1 ? x} Mg_{1 ? x} In_{1 + x} (MoO₄)₃ phase of variable composition has a NASICON-type structure (space group R $ \bar 3 $ c) AgMg₃In(MoO₄)₅ is isostructural to sodium magnesium indium molybdate of the same formula unit and crystallizes in triclinic system (space group P $ \bar 1 $ , Z = 2) with the following unit cell parameters: a = 7.0374(5) Å, b = 17.932(1) Å, c = 6.9822(4) Å, α = 87.309(6)°, β = 100.832(6)°, γ = 92.358(6)°. The compounds Ag_{1 ? x} Mg_{1 ? x} In_{1 + x} (MoO₄)₃ and AgMg3In(MoO₄)₅ are thermally stable up to 960 and 1030°C, respectively.     

Thermodynamic properties of Ni-Ga melts

The partial mixing enthalpies of the components (Δ_m $ \bar H $ \bar H _i ) of the Ni-Ga melts were measured using the high-temperature isoperibolic calorimetry at 1770 ± 5 K in wide concentration interval. The limiting partial mixing enthalpy of gallium in a liquid nickel (Δ_m $ \bar H $ \bar H _Ga^∞) is −95.5 ± 19.8 kJ mol⁻¹, and similar function of nickel in liquid gallium (Δ_m $ \bar H $ \bar H _Ni^∞) is −74.5 ± 16.4 kJ mol⁻¹. The integral mixing enthalpy of liquid alloys of this system was calculated from partial enthalpies for the whole concentration area (Δ_m H _min = −32.1 ± 2.7 kJ mol⁻¹ at x _Ni = 0.5). The Δ_m H value of liquid nickel-gallium alloys independence of the temperature is confirmed. Enthalpies of formation of liquid (Δ_m H) phases of Ni-Ga system were compared with ones for solid (Δ_f H) phases of this system. An analysis of d-metals influence on formation energy of Ga-d-Me melts was made using the values of Δ_f H for intermediate phases of these systems. The article was translated by the authors.     

基于相关性的中红外温度与发射率分离算法

温度和发射率是耦合在一起的.在精确获得大气参数的情况下,由传感器的辐射测量反演地表的温度与发射率,仍然是一个病态问题,必须采取一定的策略进行温度与发射率的分离.因此,温度与发射率的分离是红外遥感的核心问题.文章在分析无太阳直射光影响时大气下行辐射和含有大气残留的地表发射率之间关系的基础上,提出了一个针对野外测量中红外高光谱数据的温度与发射率分离算法.该算法利用大气下行辐射和含有大气残留的地表发射率之间的相关性作为判据来优化地表温度,进而获得地表发射率.基于模拟的中红外高光谱数据,对算法的精度进行评价.结果表明,该算法能够获得较高的地表温度和发射率反演精度;具有较广的适用范围,对测量过程中大气下行辐射变化不敏感;同时算法具有一定的抗噪性.     

Porphyrin effect on the surface morphology of amphiphilic polymers as observed by atomic force microscopy

Complexes of porphyrin photosensitizers (PPS) with triblock copolymers of ethylene- and propylene oxide – Pluronics^® – exhibit markedly increased activity in the generation of singlet oxygen in aqueous media, as compared to pure porphyrins. Pluronics are amphiphilic polymers with surfactant properties suitable for a number of medical applications. PPS–Pluronic systems are considered as promising agents for photodynamic therapy which implies generation of singlet oxygen in the water-based human tissue.Importantly, Pluronics are capable of solubilization of not only water-soluble, but also hydrophobic PPS providing their transfer into the aqueous phase. It has been shown earlier that specific interactions of PPS with Pluronics must play a primary role for the photocatalytic properties of PPS–Pluronic systems. In the process of solubilization of a hydrophobic porphyrin by a Pluronic, both components are dissolved in an organic solvent, which is then removed, and the dry film is re-dissolved in water. Apparently, the initial binding between the porphyrin and the lipophilic part of the polymer takes place already at the stage of the film formation.We applied atomic force microscopy (AFM) to visualize structures formed by Pluronics upon their interactions with meso-tetraphenylporphyrin (TPP). We studied the surface structure of Pluronics^® F87, F108 and F127 crystallized alone or together with TPP on silicon substrates from chloroform solutions. We found Pluronics to form similar dendritic structures independently of their molecular weight and degree of hydrophobicity. In the presence of TPP, though, we observed formation of distinct convex structures on top of the Pluronic dendrites. These structures appeared to consist of multiple flat layers placed on top of each other. Their sizes varied among the three Pluronics. We believe that TPP aggregates interact with the hydrophobic units of Pluronics causing the polymer chains to pack themselves in a distinct manner around those TPP-containing “cores”. These interactions apparently direct formation of complexes between the porphyrin and the polymer upon their dissolution in water, thus resulting in the encapsulation of TPP aggregates inside a Pluronic micelle. A single mechanism for the TPP solubilization by Pluronics is consistent with the same catalytic activity of the three TPP–Pluronic systems observed in the photooxidation of tryptophan.