Synthesis and Application of Thiadiazoloquinoxaline-Containing Chromophores as Dopants for Efficient Near-Infrared Organic Light-Emitting Diodes

series of a donor-acceptor-donor type of near-infrared (NIR) fluorescent chromophores based on [1,2,5]thiadiazolo[3,4-g]quinoxaline (TQ) as an electron acceptor and triphenylamine as an electron donor are synthesized and characterized. By introducing pendent phenyl groups or changing the pi-conjugation length in the TQ core, we tuned tile energy levels of these chromophores, resulting in the NIR emission in a range from 784 to 868 nm. High thermal stability and glass transition temperatures allow these chromophores to be used as dopant emitters, which can be processed by vapor deposition for the fabrication of organic light-emitting diodes (OLEDs) having the multilayered structure of ITO/MoO3/NPB/Alq(3):dopant emitter/BCP/Alq(3)/LiF/Al. The electroluminescence spectra of the devices based on these new chromophores cover a range from 748 to 870 nm. With 2 wt % of dopant 1, the LED device shows an exclusive NIR emission at 752 nm with the external quantum efficiency (EQE) as high as 1.12% over a wide range of current density (e.g., around 200 mA cm(-2)).

The crystal structure and drawing-induced polymorphism in poly(aryl ether ketone)s .1. Poly(oxybiphenyl-4-4'-diyloxy-1,4-phenylenecarbonyl-1,3-phenylenecarbonyl-1,4-phenylene)

Crystal structure and polymorphism induced by uniaxial drawing of a poly(aryl ether ketone) [PEDEKmK] prepared from 1,3-bis(4-fluorobenzoyl)benzene and biphenyl-4,4'-diol have been investigated by means of transmission electron microscopy (TEM), electron diffraction (ED), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC) techniques. The melting and recrystallization process in the temperature range of 250-260 degrees C, far below the next melting temperature (306 degrees C), was identified and found to be responsible for the remarkable changes in lamellar morphology. Based on WAXD and ED patterns, it was found that crystal structure of isotropic-crystalline PEDEKmK obtained under different crystallization conditions (melt-crystallization, cold-crystallization, solvent-induced crystallization, melting-recrystallization, and crystallization from solution) keeps the same mode of packing, i.e., a two-chain orthorhombic unit cell with the dimensions a = 0.784 nm, b = 0.600 nm, and c = 4.745 nm (form I). A second crystal modification (form II) can be induced by uniaxial drawing above the glass transition temperature, and always coexists with form I. This form also possesses an orthorhombic unit cell but with different dimensions, i.e., a = 0.470 nm, b = 1.054 nm, c = 5.064 nm. The 0.32 nm longer c-axis of form II as compared with form I is attributed to an overextended chain conformation due to the expansion of ether and ketone bridge bond angles during uniaxial drawing. The temperature dependence of WAXD patterns for the drawn PEDEKmK suggests that form II can be transformed into the more stable form I by relaxation of overextended chains and relief of internal stress at elevated temperature in absence of external tension.

SYNTHESIS AND PROPERTIES OF LAFEO3 ULTRAFINE POWDERS

The ultrafine LaFeO3 with particle size of 12 similar to 75nm was prepared by sol-gel method. In the process of gel to ultrafine powder, the weight loss reached 90%. The lowest forming temperature of single phase crystalline LaFeO3 ultrafine powder was ob

LaFeO_3超微粒子的制备及性质的研究

本文使用溶胶-凝胶法制备了平均粒径为12～75nm的LaFeO_3超微粒子.从凝胶至超微粒子的过程中,失重达90%.纯相晶态的LaFeO_3超微粒子的最低生成温度为600℃.粒子平均粒径随着灼烧温度的升高而显著增大.通过对不同粒径的LaFeO_3超微粒子表面光电压光谱的研究发现,随着粒子粒径的增大,粒子内部逐渐形成长程有序的晶体结构和完整的能带结构.粒子粒径越小,表面特性越明显.

SYNTHESES, CHARACTERIZATION AND CRYSTAL-STRUCTURES OF THE COMPLEXES OF RARE-EARTH WITH O-CHLOROBENZOIC ACID

REL3.H2O (RE=Y, La is similar to Lu; HL = o-chlorobenzoic acid) were synthesized. Their thermal decomposition and IR spectra were studied. The crystal structures of the complexes of neodymium, terbium and lutetium were determined by X-ray diffraction method. They crystallize in the monoclinic space group P2(1)/n and show infinite chain structures. The coordination numbers of rare earth ions are nine.

邻氯苯甲酸稀土配合物的合成、表征及结构

本文合成了邻氯苯甲酸与十五种稀土的配合物REL_3·H_2O(RE=Y,La～Lu,HL=ClC_6H_4CO_2H),研究了它们的热分解及红外光谱.测定了钕、铽及镥三种稀土的配合物晶体结构,均属单斜晶系,空间群P2_1/n,稀土离子配位数为9,配合物呈无限链状聚合结构.

Molecular cloning, genomic organization and functional analysis of an anti-lipopolysaccharide factor from Chinese mitten crab Eriocheir sinensis

Anti-lipopolysaccharide factor (ALF) represents one kind of basic proteins, which binds and neutralizes LPS and exhibits strong antibacterial activity against Gram-negative R-type bacteria. The ALF gene of Chinese mitten crab Eriocheir sinensis (Milne Edwards, 1853) (denoted as EsALF) was identified from haemocytes by expressed sequence tag (EST) and PCR approaches. The full-length cDNA of EsALF consisted of 700 nucleotides with a canonical polyadenylation signal-sequence AATAAA, a polyA tail, and an open-reading frame of 363 bp encoding 120 amino acids. The high similarity of EsALF-deduced amino acid sequence shared with the ALFs from other species indicated that EsALF should be a member of ALF family. The mRNA expression of EsALF in the tissues of heart, gonad, gill, haemocytes, eyestalk and muscle was examined by Northern blot analysis and mRNA transcripts of EsALF were mainly detected in haemocytes, heart and gonad. The temporal expression of EsALF in haemocytes after Vibrio anguillarum challenge was recorded by quantitative real-time RT-PCR. The relative expression level of EsALF was up-regulated rapidly at 2 h post-injection and reached 3-fold to that in blank group. After a drastic decrease to the original level from 4 to 8h, the expression level increased again and reached 4-fold to that in the blank group at 12 h post-injection. The genomic DNA sequence of EsALF gene consists of 1174bp containing three exons and two introns. The coding sequence of the EsALF mature peptide was cloned and expressed in Escherichia coli BL21(DE3)-pLysS to further elucidate its biological functions. The purified recombinant product showed bactericidal activity against both Gram-positive (G(+)) and Gram-negative (G(-)) bacteria, which demonstrated that the rEsALF was a broad-spectrum antibacterial peptide. All these results indicated that EsALF was an acute-phase protein involved in the immune responses of Chinese mitten crab, and provided a potential therapeutic agent for disease control in aquaculture. (c) 2007 Elsevier Ltd. All rights reserved.

Observation and theoretical analysis for the sand-waves migration in the North Gulf of South China Sea

According to the environmental characteristic of the north gulf of South China Sea, a quasi-3D mechanics model has been built for simulating the small scale sand-waves migration in the seas of southwest of Hainan Island. Based on the submarine micro-geomorphic data induced by multi-beam system and hydrographic survey record, the migrations of the sand-waves in the study area are predicted. The results show that calculation is consistent with the observation data in the groove of sand ridge, but not well in the crest of sand ridge. It is indicated that the mechanics model should be used to predict the migration of the small scale sand-waves which are dominated by bed load in the seas. This paper is very meaningful to project the route of submarine pipeline.

中更新世末期以来黄渤海陆架区衍生沉积体的研究

大量的钻孔及浅地层部面分析资料已经证实，最后冰期时期陆架上的古季风活动得到了加强，风力搬运作用是陆架上的主要外营力，长期而又稳定的干冷季风使海退后的陆架上的海相地层发生解体，出现了沙漠环境，其范围要占据黄、渤海和东海的大部分地区，并在其下风头形成衍生沉积－黄土。晚更新世末期，强劲古季风活动的结果，在中国西部形成沙漠——黄土堆积群（黄土高原及其以西的沙漠区），当它到达陆架区以后，风蚀作用继续存在，会产生同样的地质效果，因而在中国东部陆架区，形成两个新的沙漠－黄土堆积群。其一为渤海沙漠－黄土堆积群，包括渤海海底、渤海海岸一带的古沙漠活动区和辽东半岛西岸、庙岛群岛以及山东蓬莱以西的含有孔虫的黄土沉积。其二为黄海沙漠－黄土堆积群，包括苏北浅滩和长江三角洲地区全新世以前的沙漠活动区和南京一带的下蜀黄土。当冰期逐渐结束，气候转暖，冬季风逐渐减弱之际，南黄海及长江三角洲一带的沙漠范围也相应地缩小，黄土分布的位置也随之缩小。这样在原先的沙漠活动区变成了黄土分布区，也就是所谓硬粘土沉积区。随着古季风活动的进一步衰退和海面的不断升高，来自陆架区的东北风不再是干冷的气流，而是湿度逐渐增大的冷湿气流。在这种环境背景下，长江三角洲地区和陆架上出现有于沼泽发育的环境，所以在全新世海侵的前夕往往形成薄层泥炭沉积。从距今18000年的最后冰期最盛时期到距今10000年开始的全新世海侵，全球气候发生过急剧的变化。位于亚洲东部的古季风活动也经历了盛衰变化。陆架区晚更新世末期以来的地中出现沙层、硬粘土和泥炭层的沉积序列，即“三元沉积结构”，是古冬季风盛衰过程的最好记录。黄河的贯通与青藏高原隆起密切相关，黄河不可能在海拔较高的源头出现之前就已存在。冰期海退时期的陆架不存在类似现在的黄河。现代长江口以北地区在最后冰期时期，为非常恶劣的自然环境，部分地区为冻土带分布区、部分地区为古沙漠活动区。从距今12000年开始，全球气候转暖，大陆冰川逐渐消失，山地冰川后退，洋面升高，在这一过程中黄河得到较多的水量，贯穿成现代的河流系统。而后，随着海面的进一步升高，黄河三角洲不断向西迁移，而进入历史时期。在莱州湾E孔的研究中，我们发现不同时期沉积物中地球化学特征有明显差别。沉积物粒度变化与气候变化密切相关，间冰期主要以砂质沉积为主；冰期以粉砂沉积为主。但晚更新世末期时，在强烈的古冬季风作用下，发生陆架沙漠化，也沉积了一层砂质沉积。衍生沉积的成因的核心是近源沉积。黄渤海陆架衍生沉积中普遍含有孔虫、放射虫、海绿石和粒度组成较粗，大多数都属于近源沉积，真正能随高空气流进行洲际输送黄土物质，是一些非常细粒的尘埃。中更新世期间，苏北宿迁一带的第三纪紫红一红色粘土就已经出露地表，并经常受到风暴的侵蚀。当紫红一红色粘土被搬运到丘陵一带，就形成了下蜀土沉积；当它落在长江三角洲地区的湖相环境时，就形成了岩芯中所见到的杂色粘土。所以下蜀土地属于近源沉积。

Distribution patterns of chlorophyll a in spring and autumn in association with hydrological features in the southern Yellow Sea and northern East China Sea

Two field studies were conducted to measure pigments in the Southern Yellow Sea (SYS) and the northern East China Sea (NECS) in April (spring) and September (autumn) to evaluate the distribution pattern of phytoplankton stock (Chl a concentration) and the impact of hydrological features such as water mass, mixing and tidal front on these patterns. The results indicated that the Chl a concentration was 2.43 +/- 2.64 (Mean +/- SD) mg m(-3) in April (range, 0.35 to 17.02 mg m(-3)) and 1.75 +/- 3.10 mg m(-3) in September (from 0.07 to 36.54 mg m(-3)) in 2003. Additionally, four areas with higher Chl a concentrations were observed in the surface water in April, while two were observed in September, and these areas were located within or near the point at which different water masses converged (temperature front area). The distribution pattern of Chl a was generally consistent between onshore and offshore stations at different depths in April and September. Specifically, higher Chl a concentrations were observed along the coastal line in September, which consisted of a mixing area and a tidal front area, although the distributional pattern of Chl a concentrations varied along transects in April. The maximum Chl a concentration at each station was observed in the surface and subsurface layer (0-10 m) for onshore stations and the thermocline layer (10-30 m) for offshore stations in September, while the greatest concentrations were generally observed in surface and subsurface water (0-10 m) in April. The formation of the Chl a distributional pattern in the SYS and NECS and its relationship with possible influencing factors is also discussed. Although physical forces had a close relationship with Chl a distribution, more data are required to clearly and comprehensively elucidate the spatial pattern dynamics of Chl a in the SYS and NECS.

高寒草甸小嵩草种群繁殖生态学研究

研究从繁殖生态学的角度对高寒草甸小嵩草（Kobresia pygmaea）种群进行了初步研究。结果表明：小嵩草属寒冷中生密丛短根茎地下芽植物，在高寒生境中采用以营养繁殖为主、有性繁殖为辅的繁殖策略，具体体现在以下几个方面：啼然小嵩草种子产量达4553.8粒/m~2，但种子萌发率较低，室内和野外萌发率分别仅有4%和1%，经氢氧化钠溶液和赤霉素溶液处理后的种子萌发率分别为1%和2%，而剥去种皮后种子萌发率达52.6%，种皮坚硬是造成种子萌发率低的主要原因；进入种子库、保留至返青期且具有活性的种子仅占种子总数的24.35%，其室内萌发率仅有3%，而在野外理论实生苗仅为11.09个/m~2，与此相反小嵩草营养繁殖所形成的新个体数为6256.25个/m~2，远远多于种子萌发所形成的实生苗数。此外，小嵩草营养繁殖效力也远高于有性繁殖效力，营养繁殖效力占总繁殖效力的90.92%。

A molecular marker that is specific to medicinal rhubarb based on chloroplast trnL/trnF sequences

"Da-Huang" (Radix et Rhizoma Rhei, medicinal rhubarb), a famous and important Traditional Chinese Medicine, has often been confused with the adulterant species in the same genus, Rheum. Through sequencing the trnL (UAA)/trnF (GAA) regions of chloroplast DNA of thirteen species of Rheum (three medicinal rhubarb species and ten adulterant ones), a molecular marker of the medicinal species was found. A pair of PCR primers based on the sequences, was thus designed, which amplified a highly specific DNA fragment in medicinal rhubarb exclusively, and absent in the adulterants at all under an optimized PCR condition.

基于模糊聚类理论的超声无损检测缺陷的定量化分析方法研究

本文研究基于模糊聚类理论的超声无损检测缺陷的定量化分析方法.针对基于模式识别的超声定量无损检测中存在的特征提取困难、用一般特征提取方法提取的特征值质量差等问题，提出基于小波分析的缺陷回波信号的特征提取新方法；缺陷成因的复杂性决定了其形状及尺寸等特征一般具有模糊性，本文研究了缺陷识别的模糊聚类方法，以提高缺陷的识别精度及识别结果与客观事实的相符合程度。

云南武定迤腊厂铜矿含矿石英脉^40Ar-^39Ar年龄及其意义

对武定迤腊厂铜矿成矿期石英进行了^40Ar-^39Ar同位素年龄测定，得到马鞍形年龄谱，坪年龄为(784．25±0．95)Ms，等时线年龄为(783．93±8．59)Ma。地质特征研究表明：该矿床后期改造作用明显，并非同生沉积或成岩作用早期成矿，而与晋宁期Rodina大陆裂解有关。武定迤腊厂铜矿的形成可能是在Rodinia大陆裂解时，从深部带来大量成矿物质，改造成岩时期初始的矿化，形成矿床的叠加富集和最终定位，晋宁．澄江期是该矿床的主成矿期。