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81.
为了比较单线态激子与三线态激子形成截面的大小,作者将荧光染料4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) 和磷光材料factris-(2-phenylpyridine) iridium [Ir(ppy)3]共掺杂在N-vinylcarbazole (PVK)中作为发光层,制作了多层有机电致发光器件。通过对其光致发光及电致发光特性的研究,计算出Ir(ppy)3激子的形成截面比DCJTB激子的形成截面大得多。 相似文献
82.
It has been demonstrated that the mechanical and electronic properties of materials change significantly when the external dimension are confined to the nanoscale. Consequently, one-dimensional (1D) transition-metal dichalcogenide (TMDC) nanotubes (NTs), obtained from scrolling 2D TMDC, have attracted much attentions because of their intriguing properties and the chirality plays a key role in affecting the electronic properties. Taking the amount of speculations on the mechanism and the increasing needs for better device design and performance control, understanding the effect of chirality on the electronic properties is timely and relevant. Here, MoS2 NTs are comprehensively studied by first-principles calculations. The results show that the armchair (6≤ch≤14) exhibits the indirect-band-gap and zigzag (10≤ch≤20) with direct-band-gap. Moreover, the carrier mobility is enhanced with the decrease of radial length, in accord with the smaller effective mass of hole and electron for both types NTs. Finally, the formation energy showed that the smaller the radial diameters is, the harder the NTs is to form. Moreover, the similarity of lattice parameters and formation energy implies a potential possibility of transition between two types of NTs with low index chiral vectors, such as ANT(6,6)/ZNT(10,0). 相似文献
83.
移民是三峡工程成败的关键。巫山县新城址的地质问题是当前工程地质的热点问题 ,也是库区具有普遍性的问题。中段滑坡是新城址泥质灰岩整体滑坡的一部分 ,位于陡坡地带 ,形成最晚 ,结构最复杂 ,稳定性最差。滑坡的后期改造过程仍在继续 ,移民工程也严重影响着滑坡的稳定性。只有采取严格的防治措施才能进行移民工程建设。 相似文献
84.
85.
S. SimiI. Navas R. VinodkumarS.R. Chalana Mohan GangradeV. Ganesan V.P. Mahadevan Pillai 《Applied Surface Science》2011,257(22):9269-9276
Zinc nitride (Zn3N2) thin films are prepared using pulsed laser deposition (PLD) from zinc selenide (ZnSe) target at different nitrogen ambient pressures viz. 1, 3, 5, 7 and 10 Pa. The films prepared with nitrogen pressures 1 and 3 Pa are amorphous in nature, whereas the films prepared at 5, 7 and 10 Pa exhibit the presence of cubic bixbyite Zn3N2 structure with lattice parameter very close to bulk of Zn3N2. The particle size calculated by Debye Scherrer's formula is in the nano regime. Surface morphology of the films is studied by SEM and AFM analysis. Optical parameters such as band gap, refractive index and porosity of the films are calculated. Moreover, the present study confers an outlook about how do various factors such as substrate temperature, reactive supplementing gas and laser-target interaction influence the film developing process during pulsed lased deposition. 相似文献
86.
C.M. Chaves A.L. de OliveiraN.A. de Oliveira A. Troper 《Journal of magnetism and magnetic materials》2011,323(6):881-884
Recent experimental results for the magnetic hyperfine field Bhf at the nuclei of s-p impurities such as 119Sn in intermetallic Laves phases RM2 (R=Gd, Tb, Dy, Ho, Er; M=Fe, Co) and 111Cd in R Co2, the impurity occupying a R site indicate that the ratio Bhf/μ3d exhibits different behavior when one goes from RFe2 to RCo2. In this work, we calculate these local moments and the magnetic hyperfine fields. In our model, Bhf has two contributions: one arising from the R ions, and the other arising from magnetic 3d-elements; these separate contributions allow the identification of the origin of different behavior of the ratio mentioned above. For 111Cd in RCo2 we present also the contributions for Bhf in the light rare earth Pr, Nd, Pm, Sm compounds. For the sake of comparison we apply also the model to 111Cd diluted in R Ni2. Our self-consistent magnetic hyperfine field results are in good agreement with those recent experimental data. 相似文献
87.
88.
刘德龙 《光谱学与光谱分析》2000,20(6)
稀土 (La3 + ,Pr3 + )在酸性条件下与DBS 偶氮胂发生配位反应。首先对光谱数据进行因子分析法处理从而判断出只生成一类配合物 ,进而采用线性回归法计算配合物组成、摩尔吸光系数、表观稳定常数及配位体浓度。实验结果表明 :在 1mol·L-1HCl介质中 ,La3 + 、Pr3 + 与DBS 偶氮胂形成M∶L =1∶3的配合物 ,其摩尔吸光系数分别为 1 399× 10 5和 1 5 17× 10 5L·mol-1·cm-1,表观稳定常数logβ3 分别为 15 36和 15 34。 相似文献
89.
Some new tetradentate ligands with a NNOS coordination sphere were prepared and their corresponding nickel(II) complexes were synthesized and characterized by elemental analysis, IR, 1H NMR, UV–Vis and mass spectrophotometry. The thermodynamic formation constants of the complexes were measured spectrophotometrically, at a constant ionic strength of 0.1 M (NaClO4) at 25 °C in DMF solvent. The trend of the complex formation for nickel is as follows: 相似文献
90.
线团式纳米NaY分子筛复合材料的制备及形成机理 总被引:1,自引:0,他引:1
通过在偏高岭土水热合成NaY分子筛的晶化过程中加入乙醇的方法,制备了线团式纳米NaY分子筛复合材料,用XRD、SEM、ICP OES研究了晶化过程中固液相结构和组成的变化,初步探讨了其形成机理,提出了制备纳米NaY分子筛复合材料的条件. 相似文献