高效稳定性有机黄光电致发光器件

主要通过红绿磷光材料R-4B和GIr1掺杂的方法,制备了黄光OLED器件,器件结构为ITO/MoO3(X)/NPB(40nm)/TCTA(10nm)/CBP:GIr1 14%:R-4B2%(30nm)/BCP(10nm)/Alq3(40nm)/LiF(1nm)/Al(100nm),TCTA和BCP分别为电子和空穴阻挡材料,同时结合TCTA和BCP对载流子的高效阻挡作用,研究了MoO3对器件效率和稳定性的影响。发现当增加MoO3的厚度为90nm时,在较大的电压范围内,器件都具有较高的效率和色坐标稳定性。在电流密度为7.13mA/cm2时,器件达到最高电流效率29.2cd/A,亮度为2081cd/m2;电流密度为151.7mA/cm2时,获得最高亮度为24430cd/m2,电流效率为16.0cd/A;器件色坐标稳定性较好,当电压为5、10、15V时,色坐标分别为(0.5020,0.4812)、(0.4862,0.4962)、(0.4786,0.5027)。器件性能的改善主要归因于载流子注入与传输的平衡以及阻挡层对发光区域的有效限定。     

基于中性红染料的新型红色发光材料

以具有生物染色作用的中性红染料为主结构,设计合成了两个新型中性红衍生物2-(N-邻苯二甲酰亚胺)-3-甲基-8-二甲胺吩嗪(NRDl)和N,N'-二(3-甲基-8二甲胺-2-吩嗪)-1,4,5,8-萘二酰亚胺(NRD2).实验制作了结构为ITO/NPB(43 nm)/Alq3:dopant(20 nm)/Alq3(32 nm)/Lif(1 nm)/Al(120 nm)的发光器件,在掺杂质量百分比浓度分别为1.0%、2.3%和4.1%时,NRDl的发光峰值分别为582 nm、588 nm和594 nm,在电压为12 V时,发光亮度达到5552cd·m-2,2858 cd·m-2和1985 cd·m-2.在掺杂质量百分比浓度为1.0%时,NRD2的发光峰值为558 nm,在电压为12 V时,发光亮度达到938 cd·m-2.     

新型钙镁铝合金阴极对红光OLED性能的影响研究

采用不同比例的Ca/Mg/Al合金和纯Ca/Al合金阴极分别制备结构为ITO/Mo O_3(30nm)/NPB(40nm)/TCTA(10nm)/CBP:R-4B(30nm)/TPBI(10nm)/Alq3(30nm)/Ca:Mg(X%):Al(100nm)和ITO/Mo O3(30nm)/NPB(40nm)/TCTA(10nm)/CBP:R-4B(30nm)/TPBI(10nm)/Alq3(30nm)/Ca:Al(100nm)的红光有机电致发光二极管(OLED)器件及其对应的电子型器件,研究了阴极材料对器件的影响。结果发现,Ca/Mg/Al合金阴极可以提高阴极发射电子能力。当Mg掺杂质量比为20%时,器件具有最优性能,在电压为13 V时,发光亮度为10250 cd/m2,电流密度为57.099 m A/cm2,最大电流效率为18.8426 cd/A,效率较高且滚降比较平缓。原因为载流子注入比较平衡,形成了较多的激子。     

主客体掺杂和空穴阻挡对蓝色磷光OLED发光性能的影响研究

以铱配合物蓝色磷光材料Firpic作为掺杂剂,制备了基于CBP为主体的蓝色有机电致发光器件,其结构为ITO/CuPc/FIrpic:CBP(x%)/BCP/Alq3/LiF/Al,其中x%为发光层主客体掺杂浓度.分别研究了主客体掺杂浓度和空穴阻挡层BCP的厚度对器件发光性能的影响,当掺杂浓度为8%时,主客体间的能量传转移最充分,器件的启亮电压为5V,器件在20V时的亮度为7122.25cd/m2.器件电致发光(EL)光谱出现明显的红移现象,为Alq3部分参与了发光,影响了发光的色纯度,改变BCP的厚度,可以调节载流子复合区域和器件发光的色度坐标,达到改善器件发光性能的目的.     

基于红光染料掺杂的有机电压调制发光器件

制备了一种电压调制有机发光二极管(OLED),结构为ITO/CuPc(10nm)/NPB(70nm)/MADN(30nm)/MADN:DCM(2%(质量分数),10nm)/BCP 7nm/ALQ(30nm)/LiF(0.5nm)/Al(100nm).通过调节DCM的掺杂浓度和MADN:DCM厚度,发光颜色发生了随电压的连续变化.该器件的起亮电压在3V左右,当驱动电压为16V时最大亮度达到16652cd/m2,电流效率在8V时达到最大为5.78cd/A.     

基于N-苯基咔唑的红色有机电致发光材料

设计合成了一种N-苯基咔唑的衍生物:3-2-(3,3-二腈基亚甲基-5,5-二甲基-1-环己烯基)乙烯基-N-苯基-咔唑(PNCa-2CN).PNCa-2CN的甲醇溶液光致发光光谱和固体膜光致发光光谱峰值分别位于598nm和660nm.以PNCa-2CN作为红色发光材料掺杂在Alq3中,制备了结构为ITO/NPB/Alq3:PNCa-2CN(5%)/Alq3/Mg:Ag/Ag的具有较高发光效率的红色有机电致发光器件,器件的发光峰值为600nm,在外加20V直流电压时达到2372cd·m-2的发光亮度,100mA·cm-2和20mA·cm-2其亮度分别为323cd·m-2和64cd·m-2,器件最大流明效率达到1.3lm·W-1.     

高效单发光层绿色有机发光二极管的制备与性能研究

为了提升绿色有机发光二极管的效率,设计了阶梯能级结构的器件,使得载流子在器件中更有效传输,进而有效减缓了器件效率的衰减。选择热致延迟荧光材料(4s,6s)-2,4,5,6-四(9-氢咔唑-9-基)间苯二腈(4CzIPN)作为发光材料,并将其掺杂到能级匹配的主体材料1,3-二(咔唑-9-基)苯(mCP)中构成发光层,制备了一系列单发光层的绿色有机发光二极管。在发光材料的掺杂浓度为2%(wt,质量分数),发光层的厚度为20nm条件下,制得的器件性能最佳,其启亮电压为3.4V,其最大亮度、电流效率、功率效率和外量子效率分别为20706cd/m~2、50.49cd/A、41.96lm/W和16.7%。在亮度为1000cd/m~2条件下,其电流效率和外量子效率仍然高达34.06cd/A和11.6%。器件显示主峰位于504nm的4CzIPN特征发射,随着掺杂浓度的提升,越来越多的电子和空穴被4CzIPN分子所俘获,导致主体材料mCP的特征发射峰逐渐减弱。     

空穴注入层MoO_3厚度对蓝绿色磷光OLED发光特性的影响

以mCP为磷光主体材料,BGIr1为蓝绿色磷光掺杂材料,MoO3为空穴注入材料,制备5种不同厚度的MoO3蓝绿色磷光有机电致发光器件(OLED),并研究不同厚度MoO3空穴注入层对蓝绿色磷光OLED发光特性的影响。所制器件结构为ITO/MoO3(x nm)/NPB(40nm)/mCP∶BGIr1(30nm,18%)/BCP(10nm)/Alq3(20nm)/LiF(1nm)/Al(100nm),其中18%为发光层中BGIr1的掺杂量(质量分数),x为空穴注入层MoO3的厚度。研究结果表明,本实验制备器件空穴注入层MoO3的最佳厚度为20nm。当电压为13V时,MoO3厚度为20nm器件获得最大亮度为8 617cd/cm2,当电流密度为20mA/cm2时,器件获得最大发光效率为5.7cd/A。器件在488和512nm处获得两个主发射峰,发光颜色稳定,CIE坐标为(0.19,0.21)。     

新型高效红色磷光OLED器件

使用R-4B新型红色磷光染料作为掺杂剂,制作了结构为ITO/MoO3(10)/NPB(40)/TCTA(10)/CBP∶R-4B(x)/BCP(10)/Alq3(40)/LiF/Al的红色磷光器件,结合TCTA和BCP(电子和空穴阻挡材料),通过调节R-4B的掺杂比例,对器件的发光性能和发光机理进行了研究。结果表明,掺杂比例为6%时,得到光效和颜色稳定性较好的器件。在电压为4V时,电流密度为0.045mA/cm2,亮度为3.57cd/m2,最大电流效率为19.48cd/A;在电压分别为5、10和15V时,色坐标分别为(0.60,0.35)、(0.64,0.34)、(0.64,0.35)。分析认为,一方面,R-4B的发光机理主要有主体材料CBP对R-4B的能量传递及载流子直接注入R-4B形成激子;另一方面,TCTA和BCP的作用为对发光层内载流子、激子的阻挡及使空穴、电子更有效注入发光层。     

红荧烯衍生物的红光电致发光器件及其在照明中的应用

合成了一种红荧烯的衍生物,2-甲酰基红荧烯作为一种红光掺杂剂,掺杂在N,N-diphenyl-N,N-bis 1-naphthyl–1,1-biphenyl-4,4-diamine(NPB)中制备的电致发光器件,发射峰位于598nm,电流效率为2.1cd/A。用这个红光掺杂系统制备了一个白光电致发光器件,在白光器件中,2-甲酰基红荧烯,八-羟基喹啉铝(Alq3),以及NPB分别组成了白光中的红、绿以及蓝的发光成分,获得了一个白光器件,该器件显色指数高达89.8,在11V时,色坐标达(0.33,0.33),最大亮度为5000cd/m2以及最大发光效率为4.7cd/A。这些性能参数表明这个白光器件具有潜在的照明应用。另外,还讨论了器件的结构设计以及电致发光过程及机理。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.