Abstract  Dumbbell-shaped spirocyclic aromatic hydrocarbons on the basis of molecular modeling exhibit no pi-pi stacking interaction among chromophores in the molecular packing diagrams. A model compound of 1,6-di(spiro[fluorene-9,9'-xanthene]2-yl) pyrene (DSFXPy) with the pyrene-pyrene distance of up to 10.4 angstrom has been systhesized for high-performance nondoped deep-blue organic light-emitting devices. The proof-of-concept nondoped OLEDs have been fabricated with the configuration of ITO/MoOx(2 nm)/NPB(30 nm)/DSFXPy(30 nm)/TPBi(40 nm)/LiF(1 nm)/Al. DSFXPy-based nondoped OLED exhibits a maximum current efficiency of 7.4 cd/A (4.6 % at 260 cd m(-2) ) and excellent CIE coordinates (0.16, 0.15) (at 6500 cd m(-2)), surpassing most reported nondoped deep-blue OLEDs Dumbbell-shaped spirocyclic arenes will be promising candidates for OLEDs.

Abstract  Three new oxadiazole substituted carbazole derivatives 9-{4-[5-(4-tert-butylphenyl)-[1,3,4] oxadiazol-2-yl]-benzyl}-9 H-carbazole (t-CmOxa), 9-[4-5-phenyl-[1,3,4]oxadiazol-2-yl-benzyl]-9H-carbazole (p-CmOxa) and 9-[4-5-biphenyl-[1,3,4] oxadiazol-2-yl-benzyl]-9H-carbazole (d-CmOxa) were successfully synthesized and characterized by spectroscopy (NMR, UV-vis, mass spectrum and photoluminescence) and cyclic voltammetry measurements. Employing t-CmOxa as a host and Ir(DBQ)(2)(acac) (DBQ = dibenzo[f,h]quinoxaline, acac = acetylacetonate) as the dopant emitter, OLEDs with structures of ITO/NPB(30 nm)/Ir(DBQ)(2)(acac): t-CmOxa (30 nm, x%)/Alq(3)(30 nm)/Mg-0.9:Ag-0.1 were fabricated without using BCP as the hole blocking layer. Red emission was obtained with CIE coordinates (x = 0.66, and y = 0. 34) at 5 V and a very high external electrolunimescent (EL) quantum efficiency of 9.5 +/- 0.1%, and an energy conversion efficiency of 9.9 +/- 0.1 lm/W were achieved for the device when the doping concentration x is equal to 4%. (C) 2006 Elsevier B.V. All rights reserved.

Abstract  A new series of carbazolo[4,3-c]carbazoles (1-3) have been examined as hole-transporting and emitting host materials in the fabrication of red phosphorescent OLEDs (PhOLEDs). The presence of different N-substituents including hydrogen, octyl and 4-butylphenyl attached to the carbazolo[4,3-c]carbazole skeleton was aimed to condition the charge transporting properties. Due to their resemblance in the electronic structure, these carbazolocarbazoles have been compared to a commonly used hole-transporting material such as N,N'-bis(naphthalen-1-yl)-N,N'-bisphenylbenzidine (NPB). Interestingly, the introduced structural differences endow compounds 1-3 with a wide range of hole-mobilities, which provide room for adjusting the carrier balance of OLEDs. Different approaches, including bi-layer and tri-layer architectures, have been employed for the successful fabrication of Ir(piq)(2)(acac) doped OLEDs using NPB and these novel carbazolocarbazoles as hole transport and host materials. The simplified bi-layer device demonstrated high performance with maximum efficiencies of 8.7%, 5.6 cd A(-1) and 3.4 lm W-1 when using the N-alkylated derivative 2. Furthermore, the red PhOLEDs with tri-layer architecture using 3 as the HTL showed peak efficiencies of 12.2%, 8.7 cd A(-1), and 9.3 lm W-1. In addition, both compounds 2 and 3 used in OLEDs exhibited superior performance to those of devices using NPB, demonstrating their high potential for employment in phosphorescent OLEDs.

Abstract  Background: The rate of nitrogen elimination during decompression is primarily dependent on tissue perfusion and, therefore, cardiac output (CO). Negative pressure breathing (NPB) is thought to increase CO by enhancing venous return and, consequently, the rate of nitrogen elimination. This notion was investigated in the present study. Methods: Nitrogen elimination was measured in five subjects lying supine while breathing a nitrogen free gas (79% Ar, 20% O-2) supplied at-15 cm H2O (-1.5 kPa) or at atmospheric pressure. Results: Over a 2-h washout period, NPB increased nitrogen elimination by 39.2 +/- 21.7% (mean +/- SD), increased calf blood flow by 34.1 +/- 34.6%, and elevated BP. slightly during the last half of the experiment. Negative pressure breathing did not significantly change CO; the increase in nitrogen elimination may have been due to redistribution of blood flow. Conclusions: Negative pressure breathing appears to be a useful means of increasing nitrogen elimination and should be considered in situations such as decompression or treatment of decompression sickness where this effect may be beneficial.

Abstract  A model organic light-emitting diodes (OLEDs) with structure of tris(8-hydroxyquinoline) aluminum (Alq(3))/N,N'-diphenyl-N,N'-bis[1-naphthy-(1,1'-diphenyl)]-4,4'-diamine (N-PB)/indium tin oxide (ITO)-coated glass was fabricated for diffusion study by ToF-SIMS. The results demonstrate that ToF-SIMS is capable of delineating the structure of multi-organic layers in OLEDs and providing specific molecular information to aid deciphering the diffusion phenomena. Upon heat treatment, the solidity or hardness of the device was reduced. Complicated chemical reaction might occur at the NPB/ITO interface and results in the formation of a buffer layer, which terminates the upper diffusion of ions from underlying ITO. (c) 2006 Elsevier B.V. All rights reserved.

Abstract  To study the effect of multiple-quantum-well (MQW) structure on emission characteristics of white organic light-emitting diodes (WOLEDs), we fabricate trapping-type and blocking-type MQWs by inserting C545T (green dye) and TPBi, respectively, into hole transport NPB layer (ITO/CuPc/NPB/MADN:rubrene/TPBi/LiF/Al). Bright efficient and stable fluorescent white emission was obtained for the OLED with 2 trapping-type MQWs formed with C545T (thickness: 2 nm). The device current and power efficiency were greatly raised 36% (7.55 cd/A, 4.36 lm/w) relative to that of reference device (5.44 cd/A, 3.40 lm/w). Furthermore, the improvement remained even beyond the roll-off effect caused by high current density. However, the blocking-type MQW structure was difficult to optimize due to too intense blocking effect of TPBi layer. The mechanistic differences between trapping-and blocking-type MQW structures were elucidated using hole-only device and SCLC measurements. The experimental results show that trapping-type MQW structure manipulates hole transport effectively to improve charges balance which is essential in enhancing device performance, making it applicable for facile fabrication of efficient OLEDs. (C) 2012 The Electrochemical Society. All rights reserved.

Abstract  The improvement of current injection efficiency in organic light emitting diodes is demonstrated with incorporation of SubPc-doped NPB as hole injection layers. The photoemission spectra illustrate the presence of gap states and the occurrence of axial reaction on SubPc with NPB. Quantum chemistry calculation provides simulated valence-band spectra indicating that the formation of gap states is due to the HOMOs of new complexes created from the reaction of SubPc and NPB, which facilitate the hole injection at the anode interfaces. (C) 2009 Elsevier B.V. All rights reserved.

Abstract  A material compound, 9,9-bis{4'-[2 ''-(carbazolyl)-vinyl]-phenyl}fluorene (F-CZV), was specially synthesized and used to fabricate the efficient white organic light-emitting devices (WOLEDs). The absorption peaks appear at 340 nm and 346 nm in dilute dichloromethane solution and film, respectively. The photoluminescence peaks appear at 350 nm and 400 nm in the solution and film, respectively. Photoluminescent quantum yield in solution is ca 0.82 by using quinine sulfate as the standard. In an optimized electroluminescent device structure of ITO/NPB (40 nm)/F-CZV (30 nm)/BPhen (40 nm)/Mg:Ag, the saturated white-light emission was observed at Commission International De L'Eclairage (CIE) coordinates of (0.30,0.33) at 10 V. The El spectrum of the device is close to independent of the applied driving voltage. It's maximum brightness and current efficiency is 700 cd/m(2) and 0.41 cd/A, respectively. (C) 2008 Elsevier Ltd. All rights reserved.

Abstract  Charge transport materials play a crucial role in organic light-emitting diodes (OLEDs) due to their effect on reducing the operating voltage and enhancing the power efficiency. To develop hole transport materials with improved hole-mobility, two novel bromine-substituted triphenylamine derivatives: ((4-bromo-phenyl)-bis-(4-quinolin-8-yl-phenyl)-amine) Br-DQTPA and (9,9-bis-(4-triphenyl-amine)-2,7-dibromo-9H-fluorene) Br-DTF were designed and synthesized. The hole mobilities of Br-DQTPA and Br-DTF show one order of magnitude enhancement compared with non-brominated (phenyl-bis(4-quinolin-8-yl-phenyl)-amine) DQTPA and (9,9-bis-(4-triphenyl-amine)-9H-fluorene) DTF under the same electric field. Attributed to their improved hole mobilities, traditional green phosphorescent OLEDs that use Br-DQTPA or Br-DTF as a hole transport material both show an ultralow operating voltage at 1 cd m(-2) (below 2.4 V) and very high luminous efficiencies (over 21% and 90 lm W-1) without light outcoupling improvement. Those results are much better than those of DQTPA-, DTF-, and even NPB-based green devices, indicating that bromine-substitution is a promising and convenient way to achieve novel hole transport materials with improved hole-mobility.

Abstract  A novel derivative of oligo(phenylenvinylene) (OPV), 2,5-diphenyl -1, 4-distyrylbenzene with two trans-double bonds (trans-DPDSB), is used as a blue emitting material in blue and white organic light-emitting devices (OLEDs). Blue devices with a configuration of indium-tin oxide (ITO)/N,N'-diphenyl-N,N'-bis(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine (NPB)/ trans-DPDSB / tris (8-hydroxyquinoline) aluminum (Alq(3))/LiF/Al are constructed, where NPB, Alq3 and trans-DPDSB are used as hole-transporting, electron-transporting and light-emitting layers, respectively. The color of emission is changed from blue-green to pure blue when the trans-DPDSB layer is thicker. By inserting an ultrathin 5,6,11,12-tetraphenylnaphthacene (rubrene) yellow light-emitting layer between the Alq(3) and trans-DPDSB layers, white OLEDs are obtained. The maximum efficiency and luminance of the blue and white devices are 1.2, 3.0 cd/A, and 1400, 7000 cd/m(2), respectively.

Abstract  We have fabricated white organic light-emitting devices by using the phosphorescent material fac tris (2-phenylpyridine) iridium [Ir(ppy(3))] as a sensitizer, as a result, the efficiency of these devices is improved dramatically. Ir(ppy)(3) and the fluorescent dye 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9- enyl) (DCJTB) are co-doped into 4,4'-N,N'-dicarbazole-biphenyl (CBP) host, whose thickness affects both color and efficiency of the devices. Tris (8-hydroxyquinoline) aluminum (Alq) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine or BCP) are used as electron-transporting and exciton-blocking layers, respectively, and N,N'-diphenyl- N, N'-bis(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine (NPB) as a blue light-emitting as well as hole-transporting layer. The maximum efficiencies of the devices with 15 and 20 nm co-doped BCP tuning layer are 7.5 and 8.6 cd/A, respectively, and the former presents fairly pure white emission with CIE coordinates of (0.33, 0.32) at 10 V, which is very stable at various biases ( 10 - 19 V).

Abstract  The induction of antioxidant response and phenotypic plasticity of Scenedesmus quadricauda after exposure to lead (Pb) (3.6 x 10(-8) and 3.6 x 10(-7) M) at different nitrogen (N) concentrations (1.8 x 10(-4), 1.8 x 10(-5), and 1.8 x 10(-6) M) was investigated. The growth of the microalga was inhibited with decreasing N and increasing Pb concentrations. N limitation and Pb stress caused a decrease in biomass (cell density, dry weight, and chlorophyll a) production. Superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione S transferase (GST) activities generally increased with N limitation and/or increased Pb stress. CAT and POD activities decreased after 48 h, even though their activities were still higher than in those in the control, while GST and SOD activities increased throughout the N/Pb stress exposure period. The enzyme activities observed in S. quadricauda showed a significant positive correlation with N/Pb stress. These results imply that aquatic biota may suffer differently from Pb toxicity, depending on the amount of nitrogen in the environment.

Abstract  Conventional organic light emitting diode (OLED) devices were fabricated on a plastic substrate with the structure of aluminum (100 nm)/lithium fluoride (0.8 nm)/tris-(8-hydroxyquinoline) aluminum (Alq(3)) (40 nm)/N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine (NPB) (50 nm)/indium-tin-oxide (ITO) (100 nm)/polyethylene terephthalate (PET) (0.127 mm). The devices were then bent with three designated radii of curvature, some in a concave direction and others in a convex direction, to apply either a tensile or compressive stress to the OLED layers. The brightness was then measured while the device was bent while supplying a constant current. Atomic force microscopy (AFM) images of the OLED devices surface (the aluminum surface) after the bending tests were shown to compare the damage caused by the different type of the stresses. (C) 2010 Elsevier B. V. All rights reserved.

Abstract  The hole transport property of a widely used phosphorescent dye, tris(2-phenylpyridine) iridium or Ir(ppy)(3) was investigated by thin film transistor (TFT) technique. The field effect (FE) mobility of Ir(ppy)(3) was found to be 1.7 x 10 (5) cm(2) V (1)s (1). This value is actually comparable to NPB and CBP, two popular hole transporting materials for fluorescent and phosphorescent organic light-emitting diodes (FOLED and POLED), respectively. In addition, temperature dependent measurements were carried out to study the energetic disorder (sigma) of Ir(ppy)(3). The extracted sigma similar to 88 meV is comparable to those of other common amorphous organic hole transporters, which are in the range of 80-90 meV. Our findings indicate that the dye can directly act as a hole transporting component in POLEDs. Crown Copyright (C) 2010 Published by Elsevier B. V. All rights reserved.

Abstract  Diseases of hermatypic corals pose a global threat to coral reefs, and investigations of bacterial communities associated with healthy corals and those exhibiting signs of disease are necessary for proper diagnosis. One disease, commonly called white plague (WP), is characterized by acute tissue loss. This investigation compared the bacterial communities associated with healthy coral tissue (N = 15), apparently healthy tissue on WP-diseased colonies (N = 15), and WP-diseased tissues (N = 15) from Montastraea annularis (species complex) colonies inhabiting a Bahamian reef. Aliquots of sediment (N = 15) and water (N = 15) were also obtained from the proximity of each coral colony sampled. Samples for culture-dependent analyses were inoculated onto one-half strength Marine Agar (A1/2 MA) and Thiosulfate Citrate Bile Salts Sucrose Agar to quantify the culturable communities. Length heterogeneity PCR (LH-PCR) of the 16S rRNA gene characterized the bacterial operational taxonomic units (OTU) associated with lesions on corals exhibiting signs of a white plague-like disease as well as apparently healthy tissue from diseased and non-diseased conspecifics. Analysis of Similarity was conducted on the LH-PCR fingerprints, which indicated no significant difference in the composition of bacterial communities associated with apparently healthy and diseased corals. Comparisons of the 16S rRNA gene amplicons from cultured bacterial colonies (A1/2 MA; N = 21) with all amplicons obtained from the whole coral-associated bacterial community indicated a parts per thousand yen39 % of coral-associated bacterial taxa could be cultured. Amplicons from these bacterial cultures matched amplicons from the whole coral-associated bacterial community that, when combined, accounted for > 70 % total bacterial abundance. An OTU with the same amplicon length as Aurantimonas coralicida (313.1 bp), the reported etiological agent of WPII, was detected in relatively low abundance (< 0.1 %) on all tissue types. These findings suggest a coral disease resembling WP may result from multiple etiologies.

Abstract  UV-Vis can be used as an easy and forthright technique to accurately estimate the band gap energy of organic pi-conjugated materials, widely used as thin films/composites in organic and hybrid electronic devices such as OLEDs, OPVs and OFETs. The electronic and optical properties, including HOMO-LUMO energy gaps of pi-conjugated systems were evaluated by UV-Vis spectroscopy in CHCl3 solution for a large number of relevant pi-conjugated systems: tris-8-hydroxyquinolinatos (Alq(3), Gaq(3), Inq(3), Al(qNO(2))(3), Al(qCl)(3), Al(qBr)(3), In(qNO(2))(3), In(qCl)(3) and In(qBr)(3)); triphenylamine derivatives (DDP, p-TTP, TPB, TPD, TDAB, m-MTDAB, NPB, alpha-NPD); oligoacenes (naphthalene, anthracene, tetracene and rubrene); oligothiophenes (alpha-2T, beta-2T, alpha-3T, beta-3T, alpha-4T and alpha-5T). Additionally, some electronic properties were also explored by quantum chemical calculations. The experimental UV-Vis data are in accordance with the DFT predictions and indicate that the band gap energies of the OSCs dissolved in CHCl3 solution are consistent with the values presented for thin films. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  This paper presents a new three-dimensional floating random-walk (FRW) algorithm for the solution of the Nonlinear Poisson-Boltzmann (NPB) equation. The FRW method has not been previously used in the numerical solution of the NPB equation ( and other nonlinear equations) because of the non-availability of analytical expressions for volumetric Green's functions. In the past, numerical studies using the FRW method have examined only the linearized Poisson-Boltzmann equation, producing solutions that are only accurate for small values of the potential. No such linearization is required for this algorithm. An approximate expression for a volumetric Green's functions has been calculated with the help of a novel use of perturbation theory, and the resultant integral form has been incorporated within the FRW framework. The algorithm requires no discretization of either the volume or the surface of the problem domains, and hence the memory requirements are expected to be lower than approaches based on spatial discretization, such as finite difference methods. Another advantage of this algorithm is that each random walk is independent, so that the computational procedure is inherently parallelizable and an almost linear increase in computational speed is expected with increase in the number of processors. We have recently published the preliminary results for benchmark problems in one and two dimensions. In this work, we present our results for benchmark problems in three dimensions and demonstrate excellent agreement between the FRW- and finite-difference based algorithms. We also present the results of parallelization of the newly developed FRW algorithm. The solution of the NPB equation has applications in diverse branches of science and engineering including ( but not limited to) the modeling of plasma discharges, semiconductor device modeling and the modeling of biomolecular structures and dynamics.

Abstract  A novel multifunctional spiro-annulated fluorene/triarylamine based compound (STNPB) has been designed, synthesized and characterized. It exhibits a high glass transition temperature of 140 degrees C, due to the rigid spiro-configuration molecular structure. According to its suitable energy level and triplet energy (2.34 eV), improved performances, such as lower driving voltage, enhanced device power efficiency, and longer stability, are shown in organic light-emitting diodes with STNPB as the hole-transport material, compared with the ones with the widely used arylamine derivative N,N'-bis(naphthalen-l-y1)-N,N'-bis(phenyl)-benzidine (NPB). Through further studies, it has been demonstrated that the enhanced stability is attributed to suppressed crystallization process as a result of employing STNPB instead of NPB as the hole-transport material. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract  The structure of indium tin oxide (ITO) (100 nm)/molybdenum trioxide (MoO3) (15 nm)/N,N0-bis-(1-naphthyl)-N,N0-biphenyl-1,10-biphenyl-4,40-diamine (NPB) (40 nm)/4,4'-Bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) (10 nm)/5,6,11,12-tetraphenylnaphthacene (Rubrene) (0.2 nm)/DPVBi (24 nm)/Rubrene (0.2 nm)/DPVBi (6 nm)/4,7-diphenyl-1,10-phenanthroline (BPhen): cesium carbonate (Cs2Co3) (10 nm)/Al (120 nm) with high color purity and stability white organic light-emitting diode (WOLED) was fabricated. The function of the multiple-ultra-thin material (MUTM), such as Rubrene, is as the yellow light-emitting layer and trapping layer. The results show that the MUTM has an excellent carrier capture effect, resulting in high color stability of the device at different applied voltages. The Commissions Internationale De L'Eclairage (CIE) coordinate of this device at 3 similar to 7 V is few displacement and shows a very slight variation of (+/-0.01, +/-0.01). The maximum brightness of 9986 cd/m(2) and CIE coordinates of (0.346, 0.339) are obtained at 7 V. The enhanced performance of the device may result from the direct charge trapping in MUTM and it can be found in the electroluminescence (EL) process.

Abstract  The electroplex between (2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazole) zinc [Zn(4-TfmBTZ)(2)] as an electron-acceptor and N,N'-diphenyl-N,N'-bis(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine (NPB) as an electron-donor was characterized by bilayer, blend, and multilayer quantum-well (MQW) device, respectively. The blend composition and quantum-well number are effective parameters for tuning electroluminescence color. White light with high color purity and color rendering index (CRI) was observed from these devices based on Zn(4-TfmBTZ)(2)/NPB. Moreover, the blend and MQW devices all exhibit high operation stability, hence excellent color stability. For the device with 5 mol% NPB in blend layer, its Commission International Del'Eclairage (CIE) coordinate region is x=0.28-0.31, y=0.33-0.35 and CRI is 83.3-91.2 at 5-9 V. For MQW structure device with NPB of 60 nm thickness, its CIE coordinate region is x=0.29-0.32, y=0.31-0.34 and CRI=87.9-92.5 at 10-15 V. Such high color stability and purity and CRI, being close to ideal white light, are of current important for white OLED.

Abstract  We used N,N'-bis-(1-naphthyl)-N,N'-1-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB), 4,4'-N,N'-dicarbazole-biphenyl (CBP) and tris(8-hydroxyquinoline) aluminum (Alq(3)) to fabricate tri-layer electroluminescent (EL) device (device structure: ITO/NPB/CBP/Alq(3)/Al). In photoluminescence (PL) spectra of this device, the emission from NPB shifted to shorter wavelength accompanying with the decrease of its emission intensity and moreover the emission intensity of Alq(3) increased relatively with the increase of reverse bias voltage. The blue-shifted emission and the decrease in emission intensity of NPB were attributed to the polarization and dissociation of NPB excitons under reverse bias voltage. The increase of emission intensity of Alq(3) benefited from the recombination of electrons (produced by the dissociation of NPB exciton) and holes (injected from the Al cathode). (c) 2007 Published by Elsevier B.V.

Abstract  An organic alternating current electroluminescence (OACEL) device based on 4,4'-bis(N-phenyl-1-naphthylamino) biphenyl (NPB)/1,4,5,8,9,11-hexaazatriphenylene (HAT-CN)/tris(8-hydroxy-quin-olinato) aluminum (Alq(3)) doped with cesium carbonate (Cs2CO3) internal charge generation unit is demonstrated. Maximum luminance of 299 cd/m(2) is observed for Alq3 doped with 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) fluorescent emission layer when driven with a peak-peak voltage of 80 V at 120 kHz. The key charge-generation role of NPB/HAT-CN interface is studied experimentally. Furthermore, influence of evaporation sequence of this internal charge generation unit on OACEL performance is investigated. This work demonstrated that the undoped charge generation unit NPB/HATCN, can also be a good candidate for charge generation unit of OACEL device. (C) 2014 Elsevier B.V. All rights reserved.

Abstract  A white organic light emitting diode (OLED) was fabricated in which a blue light emitting host DPVBi was doped with a red dye DCJTB. The device structure was ITO/CuPc/NPB/DPVBi:DCJTB/Alq/LiF/Al, where CuPc is copper phthalocyanine, NPB is NM-bis-(1-naphthyl)N,M-diphenyl-1,1'-biphenyl-4,4'-diamine, DPVBi is 4,4!-bis(2,2-diphenylvinyl)-1,1'-biphenyl, DCJTB is 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran, and Alq is tris(8-quinolinolato) aluminium. White light emission was realized in an OLED with 0.08% DCJTB doping concentration by weight. The fabricated white OLED showed a little shift from blue to red with the increase of injection current, e.g. the CIE coordinates from (0.26, 0.32) at 4 mA/cm 2 current density to (0.24, 0.30) at 400 mA/cm(2) current density. The maximum luminance reaches 7822 cd/m(2), and the maximum luminous efficiency is 1.75 lm/W (2.45 cd/A) at 20 mA/cm(2). (C) 2003 Elsevier B.V. All rights reserved.

Abstract  Bismuth Trifluoride (BiF3), with a high thermal stability and a low deposition temperature, ;has been studied as a novel dopant for the conventional hole transporting material of N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB). The efficiency and lifetime of organic light-emitting diodes (OLEDs) have been remarkably improved by using BiF3 doped NPB. For an optimized green device, a current efficiency of 21.6 cd/A is reached, 40% higher than the control device without BiF3. And the lifetime is increased from 115 h to 222 h at room temperature. The enhanced efficiency and lifetime are attributed to the improved balance of holes and electrons in the emissive layer. Most importantly, the thermal stability at an elevated temperature of the OLEDs with BiF3 doped NPB is largely improved, showing an order of magnitude longer lifetime than the control device at 80 degrees C. (C) 2014 Elsevier B.V. All rights reserved.

Abstract  Twenty-one benchmark soils of the United States, including surface and subsurface horizons and satellites, from the Water Erosion Prediction Project (WEPP) were analyzed for phosphorus (P), using methods that include total (TP), water-soluble (WP), Bray 1 (BP), Mehlich No. 3 (MP), Olsen (OLP), New Zealand P Retention (NZP), organic (OP), anion exchange resin (AEP), and acid oxalate (P-o). Objectives of this study were to determine relationships among soil P test values and other soil properties. Knowledge and understanding of these relationships are important to researchers when evaluating soil P data sets for use in predictive models for agronomic, soil genesis, or environmental purposes. Important relationships that were developed, using simple or multiple linear regression models, among P methods and other soil properties, e.g., organic carbon (OC), total N (TN), dithionite-citrate extractable iron and aluminum (Fe-d, Al-d), and clay are as follows: TP (mg/kg) = 229.02 + 27.76 Al-d (g/kg) + 27.44 OC (g/kg) + 4.14 Fe-d (g/kg), r(2) = 0.89, p < 0.01, n = 263 (all soils) OP (mg/kg) = 114.07 + 38.07 TN (g/kg) - 14.74 pH + 6.94 OC (g/kg), r(2) = 0.80, p < 0.01, n = 262 (all soils) BP (mg/kg) = -1.82 + 1.11 MP (mg/kg), r(2) = 0.96, p < 0.01, n = 268 (all soils) P-o (mg/kg) = 16.02 - 24.27 Al-o (g/kg) + 25.59 Fe-o (g/kg) + 19.33 OC (g/kg)r(2) = 0.79, p < 0.01, n = 203 (non-calcareous) NZP (%) = 16.92 + 1.37 Al-d (g/kg) + 0.28 clay (%), r(2) = 0.91, p < 0.01, n = 203 (non-calcareous).