Investigation on slot-die coating of hybrid material structure for OLED lightings

With an attempt to fabricate large-area OLED lighting panels, we investigate slot-die coating of a small molecule (SM) hole transport layer (HTL). It is observed that SM HTL films formed by spin coating exhibit pinhole-like surface, whereas the films by slot-die coating show micro-sized hillocks due to agglomeration. As the plate temperature of the slot coater is increased, smaller hillocks appear more densely. To tackle it, a small amount of a polymer HTL is added into the SM HTL (Hybrid HTL). By the aid of entangled polymer chains, small molecules are prohibited from migrating and thus agglomerations disappear. The peak-to-peak roughness of the slot-coated hybrid HTL films is measured to be about 11.5 nm, which is slightly higher than that (~7 nm) of the polymer HTL film, but much lower than that (~1071 nm) of the SM HTL film. Similar results are also observed in spin-coated films. It is also addressed that OLED with the hybrid HTL shows higher luminous efficacy, compared to OLED with the SM HTL or the polymer HTL. We have further demonstrated that the dissolution problem occurring between two stacked layers with different solvents during slot-die coating can be suppressed to a great extent using such a combination of materials in hybrid structure.     

冷冻电镜技术——2017年诺贝尔化学奖介绍

介绍了2017年诺贝尔化学奖的3位获得者在冷冻电镜领域的主要贡献，同时介绍了冷冻电镜技术的用途、一般工作流程和其局限性，以及中国学者在冷冻电镜技术应用研究中的贡献。     

Effects of substituents on bridging ligands on the single‐molecule magnet properties of Zn2Dy2 cluster complexes

Two new Zn₂Dy₂ complexes were constructed from Zn (II) salen‐type Schiff base complex fragment and 2,6‐pyridinedimethanol (H₂pdm) or its Br‐substituted analogue (4‐bromopyridine‐2,6‐diyl)dimethanol (H₂Brpdm); their molecular formulas are [Zn₂Dy₂(L)₂(pdm)₂(MeOH)₂](ClO₄)₂ [ 1 , H₂L = N, N′‐ bis(3‐methoxysalicylidene)‐1,3‐diaminopropane] and [Zn₂Dy₂(L)₂(Brpdm)₂(MeOH)₂](ClO₄)₂ [ 2 ], the Dy (III) ions of which have a NO₇ triangular dodecahedral coordination sphere. The two complexes show not only ferromagnetic interaction but also field‐induced single‐molecule magnet (SMM) behavior, which are rare Dy (III)‐containing cluster complexes with the NO₇ triangular dodecahedral coordination sphere that can show good magnetic relaxation. The energy barrier value of complex 2 is higher than those of complex 1 and the Dy (III) complexes with the DyNO₇ triangular dodecahedral coordination configuration reported in the literature.     

On the Populations of Neon Levels in the Low Temperature Plasma of a Hollow Cathode Discharge

Atomic levels population measurements constitute an essential contribution to various aspects of plasma research: balance and cross-section of inelastic processes, admixtures effects on level excitation mechanism, purposeful optimisation of plasma parameters etc. Atomic level populations in the negative glow of a hollow cathode discharge are of utmost interest in view of the peculiarities of the spectral source: a rich spectrum consisting of gas lines, lines of the cathode material and also lines of the substances introduced in the discharge; intensive atomic and ionic lines of high excitation potentials; small spectral linewidth, convenient for analytical purposes.     

Synthesis and Structure of N-Ethoxycarbonyl-N′-O-Methoxyphenylthiourea

N-ethoxycarbonyl-N′-o-methoxyphenylthiourea was synthesized and characterized by elemental analysis, TG-DTA analysis, IR, and ¹H NMR spectrum, and single crystal X-ray diffraction analysis. The compound crystallizes as a planar molecule in the monoclinic space group P2(1)/c, with a = 9.690(2)Å, b = 8.595(2)Å, c = 15.944(4)Å, α = 90°, β = 106.467(4)°, γ = 90°, and D_calc = 1.326 g/cm³ for Z = 4. Intramolecular H-bonds promote the stability of the title compound and change the coordination ability of the thiourea ligand. Intermolecular N─H…S H-bonds link pairs of two molecules.     

Estimator of a change point in single index models

This paper considers the problem of change point in single index models. In order to obtain asymptotically valid confidence intervals for the estimation of the change point, the convergence rate and asymptotic distribution of the change point estimate is studied. Some simulation results are presented which show that the numerical performance of our estimator is satisfactory.