Achieving highly efficient white organic light-emitting diodes with reduced efficiency roll-off

A highly efficient and colour-stable three-wavelength white organic light-emitting diode with the structure of indium tin oxide (ITO)/MoO3/N,N'-diphenyl-N,N'-bis (1-naphthylphenyl)-1,1'-biphenyl-4,4'-diamine (NPB)/4,4'-N,N'-dicarbazole-biphenyl (CBP): bis(2,4-diphenylquinolyl-N,C-2') iridium( acetylacetonate) (PPQ)(2)Ir(acac)/NPB/p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-Ph):2-methyl-9,10-di(2-naphthyl) anthracene (MADN)/tris (8-hydroxyquinoline) aluminum (AlQ): 10-(2-Benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-(1)-benzopyropyrano(6,7-8-i,j)quinolizin-11-one (C545T)/AlQ/LiF/Al is fabricated and characterized. A current efficiency of 12.3 cdA(-1) at an illumination-relevant brightness of 1000 cd m(-2) is obtained, which rolls off slightly to 10.3 cdA(-1) at a rather high brightness of 10 000 cd m(-2). We attribute this great reduction in the efficiency roll-off to the wise management of singlet and triplet excitons between emissive layers as well as the superior charge injection and diffusion balance in the device.

聚对苯二甲酸1,3-丙二醇酯溶液浇铸薄膜形态结构

聚对苯二甲酸 1 ,3-丙二醇酯 ( PTT)是典型的半结晶聚合物 ,从熔体结晶形成球晶 ,在某一结晶温度范围内 ,在球晶中可观察到环带结构[1～ 4 ] .一般认为 ,环带球晶的形成归因于片晶沿球晶径向的周期性扭曲[1,2 ] .本文研究了 PTT溶液浇铸薄膜在溶剂挥发过程中等温结晶的形态结构 .1　实验部分　　 PTT样品为美国壳牌化学公司产品 ,熔点为 2 2 8℃ .将 PTT粒料于 1 1 0℃溶解在苯酚和1 ,1 ,2 ,2 -四氯乙烷 (质量比为 60∶ 40 )的混合溶剂中 ,配成质量分数为 0 .2 %～ 2 %的溶液 ,滴少许溶液在加热的云母片上 ,在预先设定的结晶温度 ( 90～ 2 0 0℃ )下等温结晶 ,然后将 PTT薄膜快速冷却至室温 .用 Leica DMLP偏光显微镜 ( PL M)和 SPA- HV30 0原子力显微镜 ( AFM)进行形态表征 .2　结果与讨论　　图 1为 PTT溶液浇铸薄膜在不同温度下等温结晶后的 PLM图 ,可以清楚地看到 Maltese十字消光现象 .PTT溶液浇铸薄膜在 90～ 1 30℃的结晶温度范围内 ,形成环带球晶 ;当结晶温度为 1 40℃...

结晶性间同立构1,2-聚丁二烯的单晶结构

近十几年来,结晶性间同立构1,2-聚丁二烯引起人们的广泛关注,但绝大多数研究工作集中在聚合物的制备、物理性质和应用方面[1～3],对于其结晶行为和晶体结构则未见报道 .原因是间同立构1,2-聚丁二烯分子侧链含有大量的双键,在较高温度下很容易交联 ,特别是高间规度的聚合物 ,由于其熔融温度高 (>200℃ )则更易产生交联,这给结晶行为和结构研究带来很大困难.结晶性间同立构1,2-聚丁二烯的晶体结构为平面锯齿链正交堆砌,Pacm空间群[4].我们曾报道了结晶性间同立构1,2-聚丁二烯的合成和溶液浇铸膜的板条状结构[5],本文采用薄膜熔体结晶的方法第一次成功地获得了间同立构1,2-聚丁二烯的单晶,并通过电子显微学和电子衍射技术确定了其晶体结构.1 实验部分1.1间同立构1,2-聚丁二烯的制备采用乙酰基丙酮铁 [Fe(acac) ]3、三异丁基铝 [Al(i-Bu)3]和氢化亚磷酸二乙酯 (DEP)的新催化体系制备间同立构1,2-聚丁二烯,具体合成路线参见文献 [5].本文所选用聚合物的1,2单元含量为 89.3 % ,间规度为 ...

3{1-[2-(-3-羟基-1-甲基-2-亚丁烯氨基)-苯亚氨基]-乙基}4-甲硫基-2,4-戊二烯-2-醇的不对称Schiff碱镍(Ⅱ)配合物的合成、结构和性质

由 5-(2-乙酰基-1-甲硫基-3-羰基-亚丁基)-丙二酸亚异丙酯 (1)与邻苯二胺及乙酸镍()经一步反应合成了3{1-[2-( -3-羟基-1-甲基-2-亚丁烯氨基)-苯亚氨基 ]-乙基} 4-甲硫基-2,4-戊二烯-2-醇(3)的不对称四齿 Schiff碱镍()配合物(2),X射线衍射结果表明,配合物 2属单斜晶系,P21/C空间群.a=1.1476(2)nm,b=1.1782(2)nm,c=1.4810(3)nm;β=111.73(2)°,V=1.8602(7)nm3,Z=4,Rf=0.0535.电化学(循环伏安)测定结果表明,该配合物在测定条件下(阳极峰电位为1.1)发生了不可逆的氧化-还原反应.

Multilayer assemblies of tungstodiphosphate anions on 1,7-diaminoheptane modified glassy carbon electrode and the electrocatalytic reduction to iodate

1,7-Diaminoheptane (DAH) had been covalently grafted on glassy carbon electrode by amino cation radical formation, which resulted in a stable cationic monolayer under proper pH conditions. Dawson-type tungstodiphosphate anion, P2W18O626- and small molecule, Ru(NH3)(6)(3+) were alternately assembled on the DAH modified electrode through layer-by-layer electrostatic interaction. Thus-prepared multilayer film had been characterized by cyclic voltammetry and X-ray photoelectron spectroscopy. The P2W18O626- multilayers exhibit high electrocatalytic response and sensitivity towards the reduction of iodate. With the increase of the number of P2W18O626- the catalytic current was enhanced and the catalytic potential shifted positively. Iodate in table salt was determined at the modified electrode containing three layers of P2W18O626- with satisfactory results. The multilayer electrode is promising as an electrochemical sensor for the detection of trace iodate.

应用玻璃微米/纳米管和循环伏安法研究邻菲咯啉加速质子在水/1,2-二氯乙烷界面的转移过程

利用循环伏安法研究了玻璃微米 /纳米管支持的水 / 1 ,2 -二氯乙烷 ( DCE)界面上邻菲咯啉加速质子的转移过程 .将装有水溶液的微米 /纳米管插入到 DCE溶液中 ,可以形成微米 /纳米级 -液 /液界面 ,在选定的实验条件下 ,其作用类似于微米 /纳米电极 .用微米管考察了此加速转移过程的半波电位与 p H值 ( 1 .1～7.5 )的关系 ,利用 Matsuda等提出的理论公式计算了邻菲咯啉与质子在有机相和水相中的络合常数比 .并用纳米管计算得到邻菲咯啉加速质子在水 / DCE界面转移过程中的标准速率常数 ( k0 )和转移系数 (α)分别为( 0 .1 83± 0 .0 5 4 ) cm/ s和 0 .70± 0 .0

高效离心分配色谱仪对异丙基膦酸单(1-己基-4-乙基)-辛酯-稀土萃取体系的研究

首次用高效离心分配色谱仪（ＨＰＣＰＣ）研究用异丙基膦酸单（１－己基－４－已基）辛酯（ＰＴ－２）分离三价重稀土元素，以分离 Ｙｂ（Ⅲ）， Ｅｒ（Ⅲ）及 Ｌｕ（Ⅲ）为例，考察了流动相酸度、流速、固定相浓度、ＨＰＣＰＣ的转速等因素对ＨＰＣＰＣ分离稀土效果的影响，并用ＨＰＣＰＣ法和液－液萃取法研究了ＰＴ－２萃取重稀土的机理。

THE ISOLATION, CHARACTERIZATION AND OXIDATION REACTION OF ACTIVE INTERMEDIATES OF CYTOCHROME-P-450 MODEL SYSTEM OXOCHROMIUM(V) TETRAPHENYLPORPHYRIN COMPLEXES

Oxochromium (V) tetraphenylporphyrin complexes, O = Cr (V) TPP (Cl) PhI. O = Cr-(V) TPP (N3) PhI and O = Cr (V)TPP (p-CH3OC6H4O)1/2PhI were isolated from the reaction of Cr (III) TPP (Cl). Cr (III) TPP (N3) Py or Cr (III) TPP (p-CH3OC6H4O) THF with iodosy

溶胶-凝胶法制备Y_3Al_5O_(12)超微粉末

使用溶胶-凝胶法制备了平均粒径为20～150nm的Y_3Al_5O_(12)超微粉末。从凝胶至超微粉末的过程中,发生了较大的失重现象。纯相晶态的Y_3Al_5O_(12)超微粉末的最低生成温度为900℃。粉末平均粒径随着灼烧时间的增加而逐渐增大,随着灼烧温度的增加而显著增大。

α-羰基烯酮式环二硫代缩醛化学(V)——β,β-1,3-亚丙二硫基-α,β-不饱和芳酮类化合物的合成

β,β-二烷硫基-α,β-不饱和酮类化合物作为一类具多反应中心的活泼中间体在有机合成中的应用,近20年来已引人注目并进行了深入广泛的研究~[1,2].以往的研究大多是针对β,β-二甲硫基-α,β-不饱和酮类化合物1进行的,而对结构相近的β,β-1,3-亚丙二硫基-α,β-不饱和酮类化合物2的研究较少.对于1类的合成,所用碱的选择至关重要~[1].实验证明叔丁醇钠和叔丁醇钾~[3～5]在1类的合成中效果较好.前文~[6]曾以六甲基二硅氨基锂(LHMDS)为碱高

水溶性聚合物和两亲聚合物:12.环氧乙烷-环氧丙烷无规共聚醚结构与性能的关系

来用连续加料法,以二元醇-KOH为引发剂合成一组不同组成的环氧乙烷-环氧丙烷无规共聚醚,并用核磁共振、红外光谱、示差扫描量热计和热失重等方法对其本体聚合物,用浊点和表面张力测定的方法对其水溶液,进行系统的表征。

杂多化合物催化性能的研究—酸碱对12-钨磷酸(盐)在苄醇氧化反应中的催化活性的影响

在所有众多结构的杂多化合物中,至今为止,具有Keggin结构的杂多酸(盐)是研究得最充分、也是唯一商品化了的杂多化合物。近年来,有许多关于Keggin结构杂多化合物作为催化剂的研究结果和应用报道。这些催化反应许多是在液相中进行的。由于杂多化合物易受酸碱影响而使结构改变或破坏,因此,反应体系中的酸碱度对杂多化合物结构的稳定性和催化活性都有明显作用。所以,研究酸碱对杂多化合物结构和催化性能的影响具有重要意义。本文考察了12-钨磷酸(盐)在苄醇氧化反应中的催化活性以及酸碱对催化活性的影响。

SYNTHESIS AND CRYSTAL-STRUCTURE OF K4H2[PMO9V3O40].10H2O

The crystal structure of the title compound was determined from single crystal X-ray diffraction at -90-degrees-C. The complex crystallizes in the tetragonal P4/mnc, Z = 2, a = 12.515(3), c = 17.636(7) angstrom. The structure was solved by Patterson and Fourier techniques and refined by least-squares to R = 0.061 for 788 reflections. The central PO4 is disordered, P-O = 1.54 angstrom, M(M = Mo or V) is 6-coordinate, M-O = 1.62-2.48 angstrom, K is 7-coordinate, K-O = 2.84-3.10 angstrom.

Ho~(3+):Gd_3Ga_5O_(12)晶体的光谱性质及强度参数

本文详细地研究了Ho~(3+):Gd_3Ga_5O_(12)(以下简称Ho~(3+):GGG)中Ho~(3+)离子在0.5～3.0μm波段内的室温及77K温度下的荧光光谱。根据Judd—Ofelt理论,计算了Ho~(3+)离子的自发辐射电偶跃迁几率与辐射寿命等光谱强度参数。

Enriched accumulation and biotransformation of selenium in the edible seaweed Laminaria japonica

Accumulations of selenium in kelp Laminaria japonica cultured in seawater was achieved by adding selenite (Na2SeO3) with or without N-P (NaNO3 + NaH2PO4) nutrients at different concentrations. Biotransformation of selenium in the kelp was investigated through measuring the selenium of biological samples and different biochemical fractionations. The results showed that the optimal selenite-enrichment concentration is 200 mg L-1, which can allow the kelp to accumulate a total selenium content from 0.51 +/- 0.15 to 26.23 +/- 3.12 mug g(-1) of fresh weight (fw). Selenium composition analysis of kelp (control group) showed that selenium is present as organic selenium, which is up to 86.22% of the total selenium, whereas inorganic selenium is barely 4.85%. When L. japonica was exposed for 56 h in seawater containing 200 mg L-1 Na2SeO3, the organic selenium was 16.70 mug g(-1) of fw (68.23%) and inorganic selenium was 4.71 mug g(-1) of fw (19.26%). The capability of accumulation of selenium was further enhanced by adding N-P nutrients to the selenite-enriched medium. Total selenium is increased to be 33.65 mug g(-1) of fw at optimal concentration of N-P nutrient (150 mg L-1 NaNO3 and 25 mg L-1 NaH2PO4), whereas the inorganic selenium was not increased and remained at 4.597 mug g(-1) of fw (13.36%), and the increased part of selenium was organic selenium. This implied that kelp L. japonica could effectively transform inorganic selenium into organic selenium through metabolism.