Change of the dominant luminescent mechanism with increasing current density in molecularly doped organic light-emitting devices

We have fabricated and measured a series of electroluminescent devices with the structure of ITO/TPD/Eu(TTA)(3)phen (x):CBP/BCP/ ALQ/LiF/Al, where x is the weight percentage of Eu(TTA)3phen (from 0% to 6%). At very low current density, carrier trapping is the dominant luminescent mechanism and the 4% doped device shows the highest electroluminescence (EL) efficiency among all these devices. With increasing current density, Forster energy transfer participates in EL process. At the current density of 10.0 and 80.0mA/ cm(2), 2% and 3% doped devices show the highest EL efficiency, respectively. From analysis of the EL spectra and the EL efficiency-current density characteristics, we found that the EL efficiency is manipulated by Forster energy transfer efficiency at high current density. So we suggest that the dominant luminescent mechanism changes gradually from carrier trapping to Forster energy transfer with increasing current density. Moreover, the conversion of dominant EL mechanism was suspected to be partly responsible for the EL efficiency roll-off because of the lower EL quantum efficiency of Forster energy transfer compared with carrier trapping.

A novel C1q-domain-containing protein from Zhikong scallop Chlamys farreri with lipopolysaccharide binding activity

The C1q-domain-containing (C1qDC) proteins are a family of proteins characterized by a globular C1q (gC1q) domain in their C-terminus. They are involved in various processes of vertebrates and supposed to be an important pattern recognition receptor in innate immunity of invertebrates. In this study, a novel member of C1q-domain-containing protein family was identified from Zhikong scallop Chlamys farreri (designated as CfC1qDC) by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) approaches. The full-length cDNA of CfC1qDC was of 777 bp, consisting of a T-terminal untranslated region (UTR) of 62 bp and a 3' UTR of 178 bp with a polyadenylation signal sequence AATAAA and a poly (A) tail. The CfC1qDC cDNA encoded a polypeptide of 178 amino acids, including a signal peptide and a C1q-domain of 158 amino acids with the theoretical isoelectric point of 5.19 and the predicted molecular weight of 17.2 kDa. The C1q-domain in CfC1qDC exhibited homology with those in sialic acid binding lectin from mollusks and C1qDC proteins from higher vertebrates. The typical 10 beta-strand jelly-roll folding topology structure of C1q-domain and the residues essential for effective packing of the hydrophobic core were well conserved in CfC1qDC. By fluorescent quantitative real-time PCR, mRNA transcripts of CfC1qDC were mainly detected in kidney, mantle, adductor muscle and gill, and also marginally detectable in hemocytes. In the bacterial challenge experiment, after the scallops were challenged by Listonella anguillarum, there was a significant up-regulation in the relative expression level of CfC1qDC and at 6 h post-injection, the mRNA expression reached the maximum level and was 4.55-fold higher than that of control scallops. Similarly, the expression of CfC1qDC mRNA in mixed primary cultures of hemocytes stimulated by lipopolysaccharides (LPS) was up-regulated and reached the maximum level at 6 h post-stimulation, and then dropped back to the original level gradually. In order to investigate its function, the cDNA fragment encoding the mature peptide of CfC1qDC was recombined and expressed in Escherichia coli BL21 (DE3). The recombinant CfC1qDC protein displayed a significantly strong activity to bind LIDS from E. coli, although no obvious antibacterial or agglutinating activity toward Gram-negative bacteria E. coli JM109, L. anguillarum and Gram-positive bacteria Micrococcus luteus was observed. These results suggested that CfC1qDC was absolutely a novel member of the C1qDC protein family and was involved in the recognition of invading microorganisms probably as a pattern recognition molecule in mollusk. (c) 2008 Elsevier Ltd. All rights reserved.

AiC1qDC-1, a novel gC1q-domain-containing protein from bay scallop Argopecten irradians with fungi agglutinating activity

The globular C1q-domain-containing (C1qDC) proteins are a family of versatile pattern recognition receptors via their globular C1q (gC1q) domain to bind various ligands including several PAMPs on pathogens. In this study, a new gC1q-domain-containing protein (AiC1qDC-1) gene was cloned from Argopecten irradians by rapid amplification of cDNA ends (RACE) approaches and expressed sequence tag (EST) analysis. The full-length cDNA of AiC1qDC-1 was composed of 733 bp, encoding a signal peptide of 19 residues and a typical gC1q domain of 137 residues containing all eight invariant amino acids in human C1qDC proteins and seven aromatic residues essential for effective packing of the hydrophobic core of AiC1qDC-1. The gC1q domain of AiC1qDC-1, which possessed the typical 10-stranded beta-sandwich fold with a jelly-roll topology common to all C1q family members, showed high homology not only to those of Cl qDC proteins in mollusk but also to those of C1qDC proteins in human. The AiC1qDC-1 transcripts were mainly detected in the tissue of hepatopancreas and also marginally detectable in adductor, heart, mantle, gill and hemocytes by fluorescent quantitative real-time PCR. In the microbial challenge experiment, there was a significant up-regulation in the relative expression level of AiC1qDC-1 in hepatopancreas and hemocytes of the scallops challenged by fungi Pichia pastoris GS115, Gram-positive bacteria Micrococcus luteus and Gram-negative bacteria Listonella anguillarum. The recombinant AiC1qDC-1 (rAiC1qDC-1) protein displayed no obvious agglutination against M. luteus and L. anguillarum, but it aggregated P. pastoris remarkably. This agglutination could be inhibited by D-mannose and PGN but not by LPS, glucan or D-galactose. These results indicated that AiC1qDC-1 functioned as a pattern recognition receptor in the immune defense of scallops against pathogens and provided clues for illuminating the evolution of the complement classical pathway. (C) 2010 Elsevier Ltd. All rights reserved.

基于切空间的局部嵌入映射近邻选择

针对欧式距离下局部嵌入映射近邻点选择的缺陷,从其定义出发,引入切空间距离,改进了近邻点的选择方法,从而能够更好的满足LLE对于局部线性的要求。论文用剩余方差测试其性能,通过对S-curve数据和Swiss-roll数据的仿真可以看到,基于切空间距离的方法能够更好的表示数据的输入/输出映射质量。

可重构模块机器人倾翻稳定性研究

介绍了一种可重构模块机器人,它可以通过构形的变化来提高系统的稳定性和抗倾翻能力.该机器人由3个模块组成,采用履带驱动,具有直线、三角、并排3种对称构形.在对移动机器人的倾翻因素和倾翻对策等问题进行分析的基础上,提出稳定锥方法,用倾翻性能指数对移动机器人的静、动态稳定性进行综合判定.讨论了变形机器人3种对称构形在仰俯、偏转、倾斜等干扰组合作用下的倾翻性能指数和综合稳定性,并进行了仿真实验和非结构环境实验.

微型ROV控制装置及控制方法

介绍了一种基于嵌入式ARM9技术的微型ROV的控制装置及控制方法。该装置可以同时进行两通道串行通讯,实现微型ROV的视频信号、潜水深度、艏向角度、纵倾角度、横摇角度、电子舱温度等数据的采集和与上位机的通讯传输;该装置可以采集16路模拟量信号和12路数字量信号,输出4路模拟量信号和12路TTL电平信号,实现推进器、水下灯、水下摄像机、云台等ROV功能器件的驱动。该装置具有通讯能力强、集成度高、功耗低等特点,可以满足微型ROV所有的常用功能要求。

水下滑翔机器人运动机理仿真与实验

对水下滑翔机器人SEA-WING的定常滑翔运动和空间定常螺旋回转运动进行机理分析,针对其特定水动力系数进行仿真,得出其运动机理特性。在此基础上,通过湖试实验数据对仿真结果进行验证,认为对于定常滑翔运动,以约36°航迹角滑行可得到最大水平速度;在相同航迹角航行情况下,水平方向速度随净浮力的增大而增大。对于定常回转运动,回转半径由载体的质量、俯仰角、水动力参数、横滚角确定。在质量和俯仰角保持不变条件下,横滚角对回转半径的影响较明显,系统的回转半径可以通过控制横滚角来实现的。

水下滑翔机器人运动分析与载体设计

水下滑翔机器人是一种新型水下机器人,具有噪声低、航行距离远、续航时间长、成本低等特点。分析了水下滑翔机器人的驱动机理和运动实现,给出了水下滑翔机器人典型运动的仿真结果,并以正在设计的一水下滑翔机试验样机为研究对象,描述了样机的整体结构布局,详细研究了浮力调节机构、俯仰调节机构和横滚调节机构的实现方法,并就样机中各执行机构的设计实现进行了论述。

水下滑翔机器人运动调节机构设计与运动性能分析

描述了水下滑翔机器人3个运动调节机构的设计,即浮力调节机构、俯仰调节机构和横滚调节机构,分析了运动调节机构与运动之间的关系.提出了采用CFX水动力计算软件分析水下滑翔机器人运动性能的方法.根据CFX计算结果,用最小二乘法参数辨识方法辨识出定常滑翔运动的水动力参数.简化了空间螺旋回转运动过程,通过CFX水动力计算方法进行回转特性分析,估算回转半径.

超短基线定位系统在ROV动力定位中应用的可行性研究

以英国 Sonardyne公司的超短基线 (Ultra- Short Base L ine)为研究对象 ,研究了该系统在各种情况下的重复定位精度 ,以及将该系统应用于水下机器人动力定位的可能性 .实验结果表明 ,即使存在姿态偏差 ,如果通过姿态传感器进行动态补偿 ,该系统仍能获得很好的重复定位精度 ,可以满足水下机器人动力定位的需要

地震力对高架桥梁上轨道车辆的动态分析与安全性研究

The stability and derailment behavior analysis of railway vehicle system has been discussed by many papers in the past. In stability, give first place to consider hunting behavior of vehicle, therefore most of papers was only consider lateral and yaw motion, but vertical motion is the important factor in derailment behavior, and it will be quite effect in stability. We will probe the running stability and derailment behavior of railway vehicle moving on the viaduct in this paper. In this paper, we use Nadal’s formula to get the derailment quotient. In this paper, the railway vehicle is considered to be three subsystems, carbody, bogie and wheelset. There are secondary suspension systems between carbody and bogies, and primary suspension systems connecting bogies and wheelsets. A vehicle with vertical, lateral, roll, and yaw directions motion is considered to derive the mathematical equations. A vehicle with three-dimensional model has 16 degrees of freedom is used to develop the equations of train motion. In this study, results show that the track shift force and derailment factor increase with an increase of ground acceleration. But for the track shift force and derailment factor, the effects of track irregularities and train speed are very small. Key words: earthquake, railway vehicle, viaduct, derailment factor.

细粒沉积物多组分粒度特征及其成因机制研究

By using high-resolution laser grain size instrument Mastersizer 2000, the grain size distribution of windblown depositions (loess and sandy dunes), aqueous sediments (lake, river, riverside and foreshore sand), weathering crust, sloping materials and other fine-grain sediments are systemically measured. The multimodal characteristics of grain size distribution of these sediments are carefully studied. The standard patterns and their grain size characteristics of various sediments are systemically summarized. The discrepancies of multimodal distribution among windblown depositions, aqueous sediments and other sediments are concluded and the physical mechanisms of grain size multimodal distribution of various sediments are also discussed in this paper. The major conclusions are followed: 1. The multimodal characteristic of grain size distribution is a common feature in all sediments and results from properties of transportation medium, dynamic intensity, transportation manner and other factors. 2. The windblown depositions are controlled by aerodynamic forcing, resulting in that the median size of the predominant mode gradually decreases form sandy dunes to loess. Similarly, the aqueous sediments are impacted by dynamic forces of water currents and the median grain size of the predominant mode decreases gradually from river to lake sediments. Because the kinetic viscidity of air is lower than of water, the grain size of modes of windblown depositions is usually finer than that of corresponding modes of aqueous sediments. Typical characteristics of sediments grain size distribution of various sediments have been summarized in the paper: (1) Suspended particles which diameters are less than 75μm are dominant in loess and dust. There are three modes in loess’ grain size distribution: fine, median and coarse (the median size is <1μm、1-10μm、10-75μm, respectively). The coarse mode which percentage is larger than that of others is controlled by source distance and aerodynamic intensity of dust source areas. Some samples also have a saltation mode which median size is about 300-500μm. Our analysis demonstrates that the interaction of wind, atmospheric turbulence, and dust grain gravity along the dust transportation path results in a multimodal grain size distribution for suspended dust. Changes in the median sizes of the coarse and medium modes are related to variation in aerodynamic forcing (lift force related to vertical wind and turbulence) during dust entrainment in the source area and turbulence intensity in the depositional area. (2) There is a predominant coarse saltation mode in grain size distribution of sandy dunes, which median size is about 100-300μm and the content is larger than that of other modes. The grain size distribution curve is near axis symmetric as a standard logarithm normal function. There are some suspended particles in some samples of sandy dunes, which distribution of the fine part is similar to that of loess. Comparing with sandy samples of river sediments, the sorting property of sandy dunes is better than of river samples although both they are the saltation mode. Thus, the sorting property is a criterion to distinguish dune sands and river sands. (3) There are 5~6 modes (median size are <1μm, 1-10μm, 10-70μm, 70-150μm, 150-400μm, >400μm respectively) in grain size distribution of lacustrine sediments. The former 4 modes are suspensive and others are saltated. Lacustrine sediments can be divided into three types: lake shore facies, transitional facies and central lake facies. The grain size distributions of the three facies are distinctly different and, at the same time, the transition among three modes is also clear. In all these modes, the third mode is a criteria to identify the windblown deposition in the watershed. In lake shore sediments, suspended particles are dominant, a saltation mode sometimes occurs and the fourth mode is the most important mode. In the transitional facies, the percentage of the fourth mode decreases and that of the second mode increases from lake shore to central lake. In the central lake facies, the second mode is dominant. A higher content of the second mode indicates its position more close to the central lake. (4) The grain size distribution of river sediments is the most complex. It consist of suspension, saltation and rolling modes. In most situations, the percentage of the saltation mode is larger than that of other modes. The percentage of suspension modes of river sediments is more than of sandy dunes. The grain size distribution of river sediments indicates dynamic strength of river currents. If the fourth mode is dominant, the dynamic forcing of river is weaker, such as in river floodplain. If the five or sixth mode is dominant, the water dynamic forcing of rivers is strong. (5) Sediments can be changed by later forcing in different degree to form some complicated deposition types. In the paper, the grain size distribution of aqueous sediments of windblown deposition, windblown sediments of aqueous deposition, weathering crust and slope materials are discussed and analyzed. 3. The grain size distribution characteristics of different sediments are concluded: (1) Modal difference: Usually there are suspended and saltation modes in the windblown deposition. The third mode is dominant in loess dust and the fifth mode is predominant in sandy dunes. There are suspended, saltation and rolling particles in aqueous sediments. In lacustrine sediments, the second and fourth mode are predominant for central lake facies or lake shore facies, respectively. In river sediments, the fourth, or fifth, or sixth mode is predominant. Suspended modes: the grain size of suspended particles of windblown depositions usually is less than 75μm. The content of suspended particles is lower or none in sandy dunes. However, suspended particles of aqueous sediments may reach 150μm. Difference in grain size of suspended modes represents difference between transitional mediums and the strength of dynamic forcing. Saltation modes: the median size of saltation mode of sandy dunes fluctuates less than that of river sediments. (2) Loess dust and lacustrine sediment: Their suspended particles are clearly different. There is an obvious pit between the second and the third modes in grain size distribution of lacustrine sediments. The phenomenon doesn’t occur in loess dust. In lacustrine sediments, the second mode can be a dominant mode, such as central lake facies, and contents of the second and the third modes change reversely. However, the percentage of the third mode is always the highest in loess dust. (3) Dune Sand and fluvial sand: In these two depositions, the saltation particles are dominant and the median sizes of their saltation modes overlay in distribution range. The fifth mode of dune sand fluctuates is sorted better than that of fluvial sand. (4) Lacustrine and fluvial sediments: In lacustrine sediments, there are 5-6 modes and suspended particles can be predominant. The second mode is dominant in central lake facies and the third mode is dominant in lake shore facies. Saltation or roll modes occurred in central lake facies may indicate strong precipitation events. In fluvial sediments, saltation particles (or rolling particles) usually dominant. 4. A estimation model of lake depth is firstly established by using contents of the second, the third and the fourth modes. 5. The paleoenvironmental history of the eastern part of SongLiao basin is also discussed by analyzing the grain size distribution of Yushu loess-like sediments in Jilin. It was found that there is a tectonic movement before 40ka B.P. in SongLiao basin. After the movement, loess dust deposited in Yushu area as keerqin desert developed. In recent 2000 years, the climate became drier and more deserts activated in the eastern part of Song-Liao basin.

拉萨地块中新生代火山作用-从大洋到大陆俯冲转换的构造演化纪录

Late Mesozoic－Cenozoic volcanic rocks are well exposed in Lhasa Terrane, southern Tibet. This research attempts to apply 40Ar/39Ar geochronology, major, trace element and Sr-Nd-O isotopic geochemistry data to constrain the spatio-temporal variations, the composition of source, geodynamic setting. The results indicate that Lhasa Terrane mainly went through three tectonic-magmatic cycle: (1) Phase of Oceanic subduction (140-80Ma). Along with the subducting beneath the Eurasian Plate of Neo-Tethys slab, the oceanic sediment and/or the subducting slab released fluids/melts to metasomatize the subcontinental lithospheric mantle, and induced the mantle wedge partially melt and produced the calc-alkaline continental arc volcanic rocks; (2) Phase of continental-continental collision. Following the subducting of the Neo-Tethys slab, the Indian Plate collided with the Eurasian Plate dragged by the dense Neo-Tethys oceanic lithosphere. The oceanic lithosphere detached from continental lithosphere during roll-back and break-off and the asthenosphere upwelled. The resulting conducted thermal perturbation leads to the melting of the overriding mantle lithosphere and produced the syn-collisional magmatism: the Linzizong Formation and dykes; (3) Following by the detachment of the Tethys oceanic lithosphere, the Indian Lithosphere subducted northward by the drive from the expanding of Indian Ocean. The dense Indian continental lithospheric mantle (±the thickened lower crust) break off, disturb the asthenosphere, and lead to the melting of the overriding mantle lithosphere, which has been metasomatized by the melts/fluids from the subducting oceanic/continental lithosphere and the asthenosphere, and produced the rift-related ultrapotassic rocks.

纵波方位属性裂缝检测技术综合研究

Fractured oil and gas reservoir is an important type of oil and gas reservoir, which is taking a growing part of current oil and gas production in the whole world. Thus these technologies targeted at exploration of fractured oil and gas reservoirs are drawing vast attentions. It is difficult to accurately predict the fracture development orientation and intensity in oil and gas exploration. Focused on this problem, this paper systematically conducted series study of seismic data processing and P-wave attributes fracture detection based on the structure of ZX buried mountain, and obtained good results. This paper firstly stimulated the propagation of P-wave in weak anisotropic media caused by vertical aligned cracks, and analyzed the rule of P-wave attributes’ variation associated with observed azimuth, such as travel-time, amplitude and AVO gradient and so on, and quantitatively described the sensitive degree of these attributes to anisotropy of fracture medium. In order to further study the sensitive degree of these attributes to anisotropy of fractures, meanwhile, this paper stimulated P-wave propagation through different types and different intensity anisotropic medium respectively and summarized the rule of these attributes’ variation associated with observed azimuth in different anisotropic medium. The results of these studies provided reliable references for predicting orientation, extensity and size of actual complicated cracked medium by P-wave azimuth attributes responses. In the paper, amounts of seismic data processing methods are used to keep and recover all kinds of attributes applied for fracture detection, which guarantee the high accurate of these attributes, thus then improve the accurate of fracture detection. During seismic data processing, the paper adopted the three dimensional F-Kx-Ky field cone filter technique to attenuate ground roll waves and multiple waves, then enhances the S/N ratio of pre-stack seismic data; comprehensively applying geometrical spread compensation, surface consistent amplitude compensation, residual amplitude compensation to recover amplitude; common azimuth processing method effectively preserves the azimuthal characteristics of P-wave attributes; the technique of bend ray adaptive aperture pre-stack time migration insures to obtain the best image in each azimuth. Application of these processing methods guaranteed these attributes’ accuracy, and then improved the accuracy of fracture detection. After comparing and analyzing a variety of attributes, relative wave impedance (relative amplitude) attribute is selected to inverse the orientation of fracture medium; attenuation gradient and corresponding frequency of 85% energy are selected to inverse the intensity of fracture medium; then obtained the fracture distribution characteristics of lower Paleozoic and Precambrian in ZX ancient buried mountains. The results are good accord with the characteristics of faults system and well information in this area.