Highly Efficient and Stable Hybrid White Organic Light Emitting Diodes with Controllable Exciton Behavior by a Mixed Bipolar Interlayer

Highly efficient and stable hybrid white organic light-emitting diodes （HWOLEDs） with a mixed bipolar interlayer between fluorescent blue and phosphorescent yellow emitting layers are demonstrated. The bipolar interlayer is a mixture of p-type diphenyl （l0-phenyl-lOH-spiro [acridine-9,9＇-fluoren]-3Lyl） phosphine oxide and n-type 2＇,2- （1,3,5-benzinetriyl）-tris（1-phenyl-l-H-benzimidazole）. The electroluminance and Commission Internationale de l＇Eclairage （CIE1931） coordinates＇ characteristics can be modulated easily by adjusting the ratio of the hole- predominated material to the electron-predominated material in the interlayer. The hybrid WOLED with a p-type：n-type ratio of 1：3 shows a maximum current efficiency and power efficiency of 61.1 ed/A and 55.8 lm/W, respectively, with warm white CIE coordinates of （0.34, 0.43）. The excellent efficiency and adaptive CIE coordi- nates are attributed to the mixed interlayer with improved charge carrier balance, optimized exciton distribution, and enhanced harvesting of singlet and triplet excitons.

Theoretical and Experimental Study on The Speed-up of Freight Train with Mixed Marshaling of Light and Heavy Vehicle

To study the influence of the speed-up of a freight train with mixed marshaling of light and heavy vehicles on the dynamic behavior,a dynamic model of the freight train was established based on the modular method of cyclic variables,and the dynamic behavior of the freight train was simulated and analyzed under different marshaling patterns,speeds and line conditions.On-site speed-up test with different marshaling freight trains was carried out,and the stability and ride-index of the train before and after the speed-up were compared and analyzed.The feasibility of increasing the speed of freight trains with mixed marshaling of light and heavy cars was demonstrated theoretically and experimentally.The results show that the theory is in good agreement with the test,which can effectively reflect the dynamic behavior of the vehicle.The dynamic behavior of the freight train in the study meets the requirements of increasing speed to 90 km/h.This paper provides a theoretical basis and method for railway freight transportation and the speed-up of freight vehicles.

Mixed d/f Complexes Zn(H2L)Ln(NO3)3(Ln=Sm,Tb and Dy)：Crystal Structure,Fluorescence and Thermal Stability

A series of isostructural d/f molecular compounds Zn（H2L）Ln（NO3）3·CH3OH（Ln = Dy（1）, Tb（2） and Sm（3）） were synthesized by the introduction of a designed multifunctional ligand N,N？,N？？,N？？？-tetra（2-hydroxy-3-methoxy-5-methylbenzyl）-1,4,7,10-tetraazacyclododecan（H4L = C（44）H（60）N4O8）. In the isostructural molecules, each crystallographically independent Zn2＋ and Ln3＋ centers are connected by two phenolic oxygen atoms. For the six-coordinate Zn-（2＋） ion, the coordination geometry can be viewed as a regular bicapped square pyramid. While for the ten-coordinate Ln-（3＋） ion, if each O,O？-chelated nitrate ligand is seen as a single coordination site, the coordination geometry can be viewed as a distorted pentagonal bipyramid. The fluorescent spectra show that compounds 2 and 3 exhibited characteristic sharp emissions of Tb-（3＋） and Sm-（3＋）, respectively, while compound 1 was found to be a single-component white-light-emitting complex in the solid state. Thermal stabilities of the three compounds were investigated by using thermal gravimetric analysis. In addition, the thermal decomposition of compound 1 was confirmed by temperature-dependent powder X-ray diffraction technique.