A novel 1,5-naphthylenediamine derivative as potential organic blue light-emitting material

A novel 1,5-naphthylenediamine derivative, 1,5-bis[N-(1-naphthyl)-N-phenyl]naphthalene diamine (NND), was designed and synthesized. This amine exhibited high glass transition temperature (T_g=127 °C) and hole transporting ability. The device with a structure of ITO/N,N′-bis(naphthalene-1-yl)-N,N′-diphenyl-benzidine(NPB)/NND/2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole (PBD)/Mg:Ag was fabricated and bright blue light emission was obtained with a peak wavelength of 432 nm, and the color coordinate in CIE chromaticity is (0.172, 0.126). The brightness of 250 cd/m² at 14 V was achieved.     

A novel fluorene derivative containing four triphenylamine groups: Highly thermostable blue emitter with hole-transporting ability for organic light-emitting diode (OLED)

Four triphenylamine groups-substituted fluorene with rather high glass transition temperature, T_g, of 165 °C, was prepared and employed together with TPD as a composite hole-transporting layer to give a device with very low turn-on voltage and high efficiency. When a hole block layer was fabricated, the new compound can be used as a light-emitting layer for OLED to give a device emitting blue color.     

Synthesis of an acrylic copolymer bearing fluorescent dye pendants and characterization as a luminescence conversion material in fabrication of a luminescence conversion light-emitting diode

A polymerizable arcyl group was incorporated into modified 4-N,N-diphenyl-9-(4-tert-butylphenyl)-1,8-naphthalimide (DBN), and the resulting compound (P-DBN) was copolymerized with methyl methacrylate (MMA) to obtain the corresponding copolymer (PMMA-co-DBN). A DBN/PMMA blend film underwent phase separation upon heating, while PMMA-co-DBN did not exhibit the phase separation problem under the same conditions. However, the fluorescence quantum yield (Ф_rel) of P-DBN was much lower (65%) than that of free DBN, and the Ф_rel of PMMA-co-DBN (36%) was lower still. The luminescent output power of a luminescence conversion light-emitting diode (LUCO LED), fabricated using PMMA-co-DBN, was not detectably changed during 288 h of operation at 20 mA, due to adequate stability of the copolymer under the experimental conditions.     

Polymer light-emitting diodes with a phenyleneethynylene derivative as a novel hole blocking layer for efficiency enhancements

This paper reports on the use of an electron transport layer (ETL) in polymer light-emitting diodes based on poly(2,5-bis(3′,7′-dimethyl-octyloxy)1,4-phenylene-vinylene) (BDMO-PPV). This ETL is inserted between BDMO-PPV and a calcium cathode as a hole blocking layer (HBL). A novel phenyleneethynylene derivative (ImPE) is proposed and compared to well-known materials such as tris(8-hydroxyquinoline) aluminum (Alq₃) and bathocuproïne (BCP). Efficient hole blocking is achieved leading to yield improvements at low luminances. With a 8 nm-thick ImPE layer, at 1 cd/m², the power efficiency reaches 1.2 lm/W whereas a BDMO-PPV-only PLED exhibits a 0.13 lm/W power efficiency. ImPE enables to reach higher performances than Alq₃ for low luminances (<20 cd/m²). However, for luminances higher than 350 cd/m², it is demonstrated that the hole blocking in no more efficient because of a too strong electric field.     

Al-Ga doped nanostructured carbon as a novel material for hydrogen production in water

Production of hydrogen using Al-Ga doped nanostructured carbon in pure water is studied. The XRD and BET techniques were used for sample analyses. Dehydrogenation data of aluminum on the ordered mesoporous carbon were collected at 353 K. In the present work the oxidation rate of activated aluminum and water is investigated depending on eutectic composition and reaction temperature. The H₂ generation rate increases with the rise of temperature. Incorporated Al-Ga-OMC nanocomposite had faster (hydrogen production rate was 112 ml H₂ min⁻¹ g⁻¹) and more efficient (hydrogen production yield was 100%) dehydrogenation kinetics than incorporated Al-OMC nanocomposite and ball-miled active aluminum.     

A nanostructured Ni/T-Nb_2O_5@carbon nanofibers as a long-life anode material for lithium-ion batteries

\In this work,nickel/T-Nb2 O5 nanoparticles encapsulated in mesoporous carbon nanofibers(denoted as Ni/T-Nb_2 O_5@CNFs) are successfully prepared through a simple electrospinning route and succedent heating treatment.The presence of Ni in carbon nanofibers is beneficial for enhancing the electronic conductivity and the initial Coulombic efficiency.Ni/T-Nb_2 O_5 nanoparticles are homogeneously incorporated in carbon nanofibers to form a nanocomposite system,which provides effective buffering during the lithiation/delithiation process for cycling stability.The Ni/TNb_2 O_5@CNFs show high surface area(26.321 m~2·g~(-1)) and mesoporous microstructure,resulting in higher capacity and excellent rate performance.The Ni/T-Nb_2 O_5@CNFs exhibit a remarkable capacity of 437 mAh·g~(-1) at a current density of0.5 A·g~(-1) after 230 cycles and a capacity of 173 mAh·g~(-1) at a current density up to 10.0 A·g~(-1) after 1400 cycles.This work indicates that nickel/T-Nb_2 O_5 nanoparticles encapsulated in carbon nanofibers can be a promising candidate for anode material in high-power LIBs.     

1-(3-Methoxycarbonyl)propyl-2-selenyl-[6,6]-methanofullerene as a n-Type Material for Organic Solar Cells

Demand for green and renewable energy is stimulating research into future materials for energy production. Thin films of materials possessing both electron accepting and donating functions play a unique role in solar energy technology because of their light weight, flexibility, and economical, low-temperature, and large-area fabrication. A [60]fullerene derivative, [6,6]-2-selenyl-C₆₁-butyric acid methyl ester (SeCBM), has been synthesized in three steps, namely through Friedel–Crafts acylation of selenophene, hydrazone formation and Bamford-Steven reaction. Organic photovoltaic device incorporating SeCBM and the conducting polymer P3HT exhibited an average power conversion efficiency of 3.26% and a champion efficiency as high as 3.81% under AM 1.5G irradiation.     

反应堆耐压壳体用Ti-5Al-3V-3Zr-0.7Cr合金热变形行为研究

利用Gleeble-3800型热模拟试验机对经过三次真空自耗熔炼的Ti-5Al-3V-3Zr-0.7Cr(wt%)合金进行热模拟等温压缩试验,研究了在750~900℃及0.001~1s_-1应变速率下的高温流变行为及再结晶行为。结果表明,在合金的高温变形过程中,流变曲线呈现出明显的先硬化后软化的流变行为特征,应变速率的降低或温度的升高都会使合金的流动应力降低;造成该合金流变软化的主要原因是动态再结晶。动态再结晶的临界应变与峰值应变之间成线性关系,随着温度和真应变增加,再结晶体积分数呈“S”型增加;应变速率减小,再结晶体积分数也呈抛物线增长。合金的最佳高温塑形变形参数为：750℃/0.001-0.01s_-1和850-900℃/ 0.01-0.1s_-1。