TiOPc/VOTPP复合材料在蓝光区的光电导性能协同增强机理

在酞菁氧钛（TiOPc)和四苯基卟啉氧钒（VOTPP）复合光生材料中发现在蓝光区表现出显著的光电导性能协同增强效应。进一步的研究表明VOTPP分子内d-π电荷转移与从VOTPP到TiOPc的分子间光致π-π电荷转移协同作用是其光敏性协同增强的主要原因。     

InClPc/TiOPc复合单层光电导体中的电荷转移现象

以氯化酞菁铟（InClPc)／酞菁氧钛（TiOPc)复合物为载流子发生材料，萘苯腙或三硝基芴酮为载流子传输材料以及聚碳酸酯（PC）3组份制备单层有机光电导体，性能测试发现光敏性出现了正或负效应。通过X射线光电子能谱（XPS）进一步研究表明，这效应与复合物分子内的M→N部分电荷转移有着密切的关系。     

Reliability of damage mechanism localisation by acoustic emission on glass/epoxy composite material plate

This investigation focuses on the analysis of the Acoustic Emission (AE) wave propagation and velocity evolution in glass/epoxy composite materials according to the fibre orientation. In this work, several piezoelectric sensors were placed on a large composite laminate in the same direction in order to analyse by one measure, the velocity and wave attenuation over a large distance. Then, the measured velocity was compared with the theoretical values of velocity that have been identified by the theoretical model analysis. This last velocity was used during a three-point bending test to analyse the damage localisation on the plate according to the amplitude distribution model developed in the “Laboratory of Roberval at the University of Technology of Compiègne”. The results of the damage localisation on the specimens were compared to the visually observed damage (delaminating, cracks…) and were corrected on the basis of the amplitude correction. Finally, the error ratio of localisation without correction was quantified. The originality of this study was to use the AE results obtained on a large laboratory specimen in order to improve the AE testing on an industrial structure scale.     

Design and roles of RGO-wrapping in charge transfer and surface passivation in photoelectrochemical enhancement of cascade-band photoanode

Fast charge transfer and anti-photocorrosion are two crucial factors for developing efficient,durable photoanodes for photoelectrochemical (PEC) cells.Reduced graphene oxide (RGO) is a promising photoanode element that can provide both of these.In this study,we elucidated the roles of RGO in the charge transfer and surface passivation of photoanodes by the precise design of a RGO-wrapped photoanode and examination of its PEC properties.Arrays of hetero-nanorods (HNRs) with three different designs were fabricated as photoanodes using RGO,CdSe nanopartides (NPs),and ZnO nanorods (NRs) as building blocks.CdSe@ZnO HNRs were prepared by decorating ZnO NRs with CdSe NPs.Finite-element analysis and experimental studies demonstrated that in the CdSe@ZnO HNRs,if only the ZnO NRs were wrapped by RGO,the conductivity between CdSe and ZnO was enhanced by RGO to shuttle charges.If RGO only surrounded the outside of the CdSe@ZnO HNRs,the corrosion was slowed owing to the passivation effect of RGO,which increased the electron lifetime of the photoanode.If both CdSe and ZnO were fully wrapped by RGO,the advantages of the two aforementioned cases were both obtained.RGO-wrapped CdSe@ZnO HNRs with position-controlled designs are promising photoanode materials with a high PEC efficiency,and the developed synthesis process can be applied to explore the design and fabrication of next-generation photoanodes using RGO as a building block.     

Assessment of fatigue damage evolution in woven composite materials using infra-red techniques

Thermoelastic stress analysis (TSA) is used to study the growth of fatigue damage in single and two ply, 2 × 2 twill woven composite materials. Test specimens were subjected to a uniaxial tensile cyclic loading with maximum stresses of 10%, 15% and 20% of the ultimate failure stress. The development of fatigue damage locally within the weft yarns is monitored using high resolution TSA. The specimens were subsequently inspected using optical microscopy to evaluate the location and extent of cracks. Cracks were found in the weft fibres, running transverse to the loading direction. It is demonstrated that the lighter weight fabric is more resilient to damage progression. A signature pattern is identified in the TSA phase data that indicates the onset and presence of fatigue damage in the composite material.     

纳米SiC/低密度聚乙烯复合材料的空间电荷与电导特性

利用熔融共混法制得不同纳米SiC质量分数（0.5%、2.0%、3.0%）的纳米SiC/低密度聚乙烯（LDPE）复合材料,研究了添加纳米SiC颗粒对LDPE介电性能的影响。利用SEM观测了纳米SiC颗粒的分散特性,利用电声脉冲（PEA）法测得40 kV/mm场强作用下纳米SiC/LDPE复合材料的空间电荷分布特性。利用热刺激电流（TSC）进一步验证纳米SiC添加能够提高LDPE的陷阱浓度。结果表明:纳米SiC颗粒能够均匀地分散在LDPE中,未出现较大的团聚现象。纳米SiC质量分数为0.5%、2.0%和3.0%的纳米SiC/LDPE复合材料空间电荷注入量明显低于LDPE。短路600 s后的残留空间电荷密度远小于LDPE。纳米SiC/LDPE复合材料的空间电荷注入量与电导率均随着纳米SiC的增加而减少。纳米SiC质量分数为3.0%的纳米SiC/LDPE复合材料场强非线性系数为2.6,远小于LDPE的4.3。TSC曲线表明纳米SiC/LDPE复合材料内部制造了大量的陷阱,抑制了载流子在材料内部的输运,从而阻碍了空间电荷的迁移和积聚。      

Large enhancement of second harmonic generation in highly cerium doped lead-phosphate glass

The influence of lead and cerium concentration on photoinduced second harmonic generation (SHG) in lead-phosphate glasses has been studied. It has been shown that SHG can be considerably enhanced by increasing of lead and cerium concentration. We also have found that cerium greatly extends the induced nonlinearity lifetime. Physical mechanism of the phenomenon is discussed.     

SiCw／LD2A1复合材料超塑变形协调机制的研究

为了研究金属基复合材料超塑变形时液相的作用,分析了金属基复合材料界面处的局部应力,当由滑移引起的界面处局部分应力值高于界施加于同处应力值时,复合材料在含有液相的状态下超塑变形能力量大,反之,变形能力在不含液相的纯固相状态最大,因此,可以认为塑性变形过程中当有应力集中产生时,为了缓解应力集中,液相必需存在才能取得超塑性,当无应力集中时,超塑变形不需要液相的存在,上述理论与实验结果是一致的。     

铝铜厚度比对复合药型罩侵彻能力影响的计算研究

为了将复合聚能罩从兵工领域引入到民用爆破工程,基于工业用火工品特点,研究了材料廉价易得、制作工艺简单的定厚度比铝铜双层复合药型罩。制作时,在炸药与铜罩(内层罩)之间配置一层阻抗低于铜的铝罩(外层罩),便能提高炸药能量利用率。通过数值模拟计算了不同铝铜厚度比射流的侵彻过程,发现射流头部速度随铝铜厚度比提升而增加,而侵彻深度随铝铜厚度比的增加呈先增后降的趋势,铝铜厚度比为3时获得最佳侵彻深度。铝铜厚度比小于5时,侵彻孔径变化较小。     

TDI改性MWCNTs/环氧树脂复合材料的制备和导热性能研究

制备了多壁碳纳米管(MWCNTs)/甲苯二异氰酸酯(TDI)反应生成物和环氧树脂(Ep)的复合物,并对其进行了红外表征及形态学研究.扫描电镜(SEM)显示碳纳米管很好地分散在环氧树脂中.X射线衍射仪(XRD)测试结果表明复合材料为半结晶态.复合材料的体积电阻率由纯环氧树脂的1016降低到108,导热系数提高到纯环氧树脂的近1倍.