Color-stable,reduced efficiency roll-off hybrid white organic light emitting diodes with ultra high brightness

High-brightness and color-stable two-wavelength hybrid white organic light emitting diodes （HWOLEDs） with the configuration of indium tin oxide （ITO）/ N, N, N, N-tetrakis（4-methoxyphenyl）-benzidine （MeO-TPD）： tetrafluoro-tetracyanoqino dimethane （F4-TCNQ）/N,N-di（naphthalene-1-yl）-N,N-diphenyl-benzidine （NPB）/ 4,4-N,N-dicarbazolebiphenyl （CBP）： iridium （III） diazine complexes （MPPZ） 2 Ir（acac）/NPB/2-methyl-9,10-di（2-naphthyl）anthracene （MADN）： p-bis（p-N,N-di-phenyl-aminostyryl）benzene （DSA-ph）/bis（10-hydroxybenzo[h] quino-linato）beryllium complex （Bebq2）/LiF/Al have been fabricated and characterized. The optimal brightness of the device is 69932 cd/m2 at a voltage of 13 V, and the Commission Internationale de l’Eclairage （CIE） chromaticity coordinates are almost constant during a large voltage change of 6–12 V. Furthermore, a current efficiency of 15.3 cd/A at an illumination-relevant brightness of 1000 cd/m2 is obtained, which rolls off slightly to 13.0 cd/A at an ultra high brightness of 50000 cd/m2. We attribute this great performance to wisely selecting an appropriate spacer together with effectively utilizing the combinations of exciton-harvested orange-phosphorescence/blue-fluorescence in the device. Undoubtedly, this is one of the most exciting results in two-wavelength HWOLEDs up to now.

Realizing External Quantum Efficiency over 25% with Low Efficiency Roll-Off in Polymer-Based Light-Emitting Diodes Synergistically Utilizing Intramolecular Sensitization and Bipolar Thermally Activated Delayed Fluorescence Monomer

Since polymer-based light-emitting diodes(PLEDs)arewellsuited building blocks for large-area and low-cost flexible display equipment,state-of-the-art thermally activated delayed fluorescence(TADF)PLEDs are in high demand.To respond to this demand,light-emitting TADF units have initially been modified with electron-transporting units to balance the carrier transport of regiorandom TADF polymers,and simultaneously,an intramolecular sensitizing strategy has also been employed by covalently incorporating TADF sensitizers with light-emitting TADF units and hosts in conjugated polymers to accelerate the spin-flip of triplet excitons.Superior photophysical properties have been achieved by a rational regulation of the proportions of each component,achieving a photoluminescence quantumyield of 90%,an extremely high rate of reverse intersystem crossing of 3×106 s−1,and a relatively low nonradiative decay rate of around 105 s−1.As a result,the solutionprocessed PLEDs can attain an external quantum efficiency(EQE)value of 25.4%with emission peaks of around 550 nm,representing record-high performance for PLEDs.The efficiency roll-off can also be significantly suppressed,maintaining an EQE value of 24.2%at 1000 cd/m2 with ideal efficiency roll-off of lower than 5%.Encouragingly,this work provides a valid strategy to tackle the imperative need for PLEDs with high EQE and low efficiency roll-off.

SPMT在井口平台组块滚装装船方式中的应用

针对自行式模块化运输车(Self-Propelled Modular Transporter,SPMT)滚装装船方式,以蓬莱19-3油田4腿式井口平台组块为例,在称重布置、临时支撑布置、运输抬梁布置和轴线布置等方面对SPMT装船方案进行适配性设计,在组块强度、运输抬梁强度和SPMT车板强度等方面对该方案的运输强度进行校核,并对该方案进行拓展。该方案可为后续井口平台组块装船方案设计提供参考。

滚装船在拖轮辅助下丁靠斜坡道的船舶系泊试验研究

文章以某码头工程为例,针对1万t滚装船在拖轮辅助下丁靠斜坡道开展船舶系泊物理模型试验,分别对风、浪、流不同组合工况下的缆绳系缆力、船舶运动量等进行了试验研究,给出了作业及系泊条件,可为设计和运营提供参考。结果表明设计方案缆绳布置方式总体较为合理,使用拖轮辅助可以有效地平衡风、浪、流对滚装船的作用力,各组缆绳缆力未超过50%破断力的设计标准;对于系泊系统中各特征量,动力因素的影响次序自大至小依次为:波浪、风和水流,其中波浪周期在影响因素中最为显著;同样的波浪条件下,SW向波浪比WSW向波浪作用更为不利,实际运行管理中应结合波浪数模成果及码头前实际波浪方向调整系泊和作业状态。

A simple unilateral homogenous PhOLEDs with enhanced efficiency and reduced efficiency roll-off

In this paper, highly efficient phosphorescent organic lighting emitting diodes （PhOELDs） with low efficiency roll-off are demonstrated by using a unilateral homogenous device structure with wide band-gap material 4, 4＇, 4＂-tri（N-carbazolyl）-triphenylamine （TCTA） as hole transporting layer and emitting layer （EML）. The opti- mized blue device exhibits a high power efficiency of 40 lm/W, external quantum efficiency of 19.2% and current efficiency of 37.7cd/A. More importantly, the device exhibits a low efficiency roll-off at 1000 cd/m^2. In addition, the white homogenous PhOLEDs only exhibits the efficiency roll-off 5.6% and 17.5%, corresponding to the brightness of 1000 and 5000cd/m^2 respectively. These interesting results demonstrate that the simple unilateral homogenous device structure is a promising way to enhance the device efficiency and reduce the efficiency roll-off.

Suppressed threshold voltage roll-off and ambipolar transport in multilayer transition metal dichalcogenide feed-back gate transistors

The layered semiconducting transition metal dichaloogenides(S-TMDs)have attracted considerable interest as the channel material for field-effect transistors(FETs).However,the multilayer S-TMD transistors usually exhibit considerable threshold voltage(Vn)shit and ambipolar behavior at high source-drain bias,which is undesirable for modern digital electronics.Here we report the design and fabrication of double feedback gate(FBG)transistors,i.e.,source FBG(S-FBG)and drain FBG(D-FBG),to combat these challenges.The FBG transistors differ from normal transistors by including an extra feedback gate,which is directly connected t0 the source/drain electrodes by extending and overlapping the source/drain electrodes over the yttrium oxide dielectrics on s-TMDs.We show that the S-FBG transistors based on mutilayer MoSg exhibit nearly negligible VIn rlloff at large source drain bias,and the D-FBG mutilayer WSe2 transistors could be tailored into either n-type or p-type transport,depending on the polarity of the drain bias.The double FBG structure offers an effective strategy to tailor multilayer s-TMD transistors with suppressed Vn roll-off and ambipolar transport for high-performance and low-power logic applications.

Novel thioxanthone host material with thermally activated delayed fluorescence for reduced efficiency roll-off of phosphorescent OLEDs

2,7-Di（9,9-dimethyl-9H-fluoren-l-yl）-9H-thioxanthen-9-one （DMBFTX） with thermally activated delayed fluorescence （TADF） was well designed and synthesized. The phosphorescent organic lightemitting device （PHOLED） based on this novel TADF host material displays a stable red phosphorescence region, a peak external quantum efficiency （EQE） value of 12.9% and a low EQE roll-off of 38.8%at a luminance of 10000 cd/m2, which is benefited from the reverse intersystem crossing （RISC） of TADF host and less populated triplet exitons. Notably, the red device based on the TADF host DMBFrX exhibits superior electroluminescence performance and reduced efficiency roll-offcompared with the one hosted by commercially available host 1,3-bis（9-carbazolyl）benzene （mCP）, illustrating the high potential of employing the TADF host material with small energy gap to reduce efficiency roll-off in PHOLED.

Efficient deep blue OLEDs with extremely low efficiency roll-off at high brightness based on phenanthroimidazole derivatives

Phosphorescent and thermally activated delayed fluorescence(TADF)emitters can break through the spin statistics rules and achieve great success in external quantum efficiency(over 5%).However,maintaining high efficiency at high brightness is a tremendous challenge for applications of organic light emitting diodes.Hence,we reported two phenanthroimidazole derivatives PPI-An-CN and PPI-An-TP and achieved extremely low efficiency roll-off with about 99%of the maximum external quantum efficiency(EQEmax)maintained even at a high luminance of 1000 cd/cm2 based non-doped devices.When doping the two materials in CBP(4,4'-bis(N-carbazolyl)-1,1'-biphenyl),the doped devices still exhibited excellent stability at high brightness with CIEy≈0.07 and low turn-on voltage of only 2.8 V.The state-ofthe-art low efficiency roll-off makes the new materials attractive for potential applications.It is the first time that the Fragment Contribution Analysis method has been used to analyze the excited state properties of the molecules in the field of OLEDs,which helps us understand the mechanism more intuitively and deeply.

A Series of Pure Orange-yellow Iridium Complexes with Low Efficiency Roll-off： a Computational Study

The electronic structures and spectroscopic properties of heteroleptic cyclometalated iridium（Ⅲ） complexes were investigated. The geometries, electronic structures, and the lowest-lying excited states of （DBQ）2Ir（acac） and （MDQ）2Ir（acac） were investigated via density functional theory-based approaches. A series of designed models of （DBQ）2Ir（dpis）, （DBQ）2Ir（tpip）, （MDQ）2Ir（dpis） and （MDQ）2Ir（tpip） was also calculated for comparison. The structures in the ground and excited states were optimized via B3LYP method. The lowest absorptions and emissions spectra were evaluated via TD-B3LYP and TD-PBE1PBE methods, The computational results reveal that the emission peaks of the designed complexes are at around 585-640 nm, which belong to the orange-yellow wavelength. The frontier molecular orbital properties indicate that the Ir（Ⅲ） complexes have low efficiency roll-off.

一种大型港口起重机整机滚装方式装卸船方案

大型港口起重机设备在制造厂及用户码头具备条件的情况下,通常在制造厂完成绝大部分的安装及调试工作后,采用整体滚装方式进行装船、卸船。结合工程实践,给出了一种大型港口起重机整机滚装方式装卸船方案,介绍了船舶选择、施工过程及其关键技术要点。

太极拳“掤捋挤按”的文化隐喻

该文运用文献资料法等研究方法,对习练太极拳的要求和论述进行了梳理和剖析,并结合笔者自身对太极拳的体悟,对其外在的技术特点和内在的文化隐喻进行了分析。认为“掤捋挤按”是太极拳的技术之基,其中蕴含“以方为体,以圆为用”的立身之本;内隐“以形为本,以意律体”的中和之法;追求“以内引外,整合化一”的无为之境。最终指出,太极拳不仅要在技术上回归,更要追求文化上的传承,需找回太极拳“掤捋挤按”中隐喻的文化意涵。

基于机器视觉的棒线材废料尺寸综合测量

从控制棒线材剪切废料长度进而提高棒线材轧制过程自动化水平的角度出发,提出了一种基于机器视觉的棒线材剪切废料外形尺寸测量方法,并设计了对应图像采集装置。基于图像合并和UNet神经网络,该方法提出了剪切废料中变形段和正常段的判定标准并给出了变形段长度测量结果。所提出的测量方法对检测环境和目标外形的变化具有鲁棒性,对于样本量要求远低于其他传统神经网络因而更适用于实际工业数据集,而长度方向的量程也可随图像数量的增减而灵活调整。采用真实剪切废料样本进行测量实验,结果表明该测量方法简单有效、精确度高,且由于模型具有轻量化、可预训练的特点,该方法具备在线监测部署潜力。

大型结构物滚装装船关键技术研究

大型钢结构物的装船工艺一般有四种方式:起重船吊装工艺、轨道滑车工艺、滑移装船工艺和滚装装船工艺。受场地和其他因素的限制,越来越多的项目现采用滚装装船技术,但滚装装船过程整个过程是否安全可行关系到整个工程成败的重要环节,因此大型结构物滚装装船的关键技术—小车梁载荷分配的研究显得尤为重要,不但能提高整个过程的科学性、安全性、可靠性,也使大型结构物滚装装船工艺成为安全可行。

中高碳钢在UCM连轧机组稳定轧制攻关

通过对中高碳钢(45、65Mn)在酸轧UCM五机架连轧机组轧制过程中频繁发生1#机架出口失稳断带原因分析,明确了断带发生的具体原因,并开展了UCM轧机二级模型控制参数优化试验。通过不断的模拟试验和现场实际生产试验,优化了中高碳钢轧制过程参数控制,实现了中高碳钢在UCM五机架连轧机组连续稳定轧制,并为后期更高强度钢带在UCM轧机的稳定轧制积累了经验,为冷轧新产品研发创造了有利条件。

四足机器人特定复杂运动技能控制

为了提高四足机器人的运动多样性和地形适应性,提出一种复杂运动行为控制方法,通过构建四足机器人动力学模型,在此基础上进行离线滚动优化预测,生成四足机器人复杂行为的期望轨迹。在运动学、关节扭矩、接触力、运动状态和地形高度等非线性约束下更全面地优化了轨迹,设计在线轨迹跟踪控制器与落足控制器,实现四足机器人复杂行为的在线控制。在多复杂运动的动态仿真环境下评估了所提方法,机器人可以实现前跳、后空翻、前空翻和旋转跳跃,并可以在给定地形信息下跳跃障碍物。将在线轨迹跟踪控制器迁移到四足机器人物理样机中,完成了四足机器人向前跳跃的实验。实验结果表明,所提出的方法能够使四足机器人有效地完成多种特定复杂运动技能的稳定控制。

具有多工作模式的电机式主动横向稳定器控制策略研究

为兼顾不同工况下侧倾稳定性及平顺性,并考虑驾驶员驾驶习惯的差异性,本文提出并研究具有多工作模式的电机式主动横向稳定器(Electric active anti-roll stabilizer,EAAS)模糊控制策略。首先利用MATLAB/Simulink和Vehicle Network Toolbox建立具有EAAS的九自由度整车动力学仿真模型,然后采用Mamdani模糊控制方法,构建具有多工作模式的EAAS模糊控制策略,并利用角阶跃工况和鱼钩工况分别开展离线仿真,最后设计出EAAS电子控制单元及其半实物仿真台架,并通过半实物仿真进一步验证了EAAS模糊控制策略的有效性,主要研究结果表明,基于多工作模式的EAAS模糊控制策略能够有效提高车辆侧倾稳定性。

船舶滚装通道结构设计与轻量化优化

船舶滚装通道是船舶上重要的货物运输通道,其结构设计和轻量化优化对于提高船舶运输效率和降低能耗具有重要意义。文章分析了船舶滚装通道的结构设计和轻量化优化,并探讨了未来的优化方向。

平方根升余弦滚降滤波器在消除码间串扰中的应用

先分析了无线通信系统中存在码间串扰(ISI)现象,然后又从理论上分析了匹配滤波的频域和时域要求,为平方根升余弦滚降滤波器应用于消除码间串扰提供了理论依据。以16正交幅度调制(16QAM)的调制与解调为例,通过观察接收端的星座图的质量和误比特率,验证了平方根升余弦滚降滤波器能够使无线通信系统的码间串扰得到极大的改善。

燃油导管滚压连接与转矩控制工艺分析

铝合金导管与管套连接技术主要配合柔性连接器应用在飞机燃油系统中。针对飞机燃油系统的大规格导管,利用有限元分析和试验的方法,探究不同外径下转矩选用对导管与管套滚压连接的成形影响,从而预测5A02-O材料、100 mm外径导管滚压转矩,最终通过密封性试验和拉脱试验验证控制的转矩能否符合试验要求。研究表明,在相同壁厚和材料下,导管的内径大小和转矩呈二次项关系。若增大壁厚,每增大0.1778 mm的壁厚,转矩约增大10%。导管材料的抗拉强度越大,滚压转矩也越大。研究的数据和结果对工程应用中质量控制和工艺优化具有一定的指导作用。

磁吸式防渗膜截渗墙关键施工技术研究

HDPE防渗膜截渗墙目前还未进行大范围推广,但其良好防渗性能已在实际项目中得到验证。根据某磁吸式防渗膜截渗墙项目,对防渗膜截渗墙的优化-磁吸式防渗膜截渗墙施工关键技术进行研究,包括施工工艺流程中的胶磁粘贴、防渗膜卷膜、铺膜、防渗膜搭接处处理、锁扣管松动顶拔。结果表明,磁吸式防渗膜截渗墙施工过程中,胶磁粘贴位置须提前设置;防渗膜卷膜须根据防渗膜下放次序进行调整;铺膜过程须配置合理配重进行;防渗膜搭接处须进行压膜处理以保证搭接效果;锁扣管顶拔前松动处理时间须进行有效控制避免墙体损坏或顶拔困难的情况出现。结合施工过程关键施工技术,给出了部分合理施工建议,以期为类似工程提供参考。