| 1 | Influences of fluorine auxochrome in fluorene molecular electroluminescent material on optoelectronic property显示文摘The UV-Vis absorption and photoluminescence (PL) spectra of 2,3-bis(9,9-dihexyl-9H-fluoren-2-yl) quinoxaline (Py), 2,3-bis(9,9-dihexyl-9H-fluoren-2-yl)-6,7-difluoroquinoxaline (F2Py) and 2,3-bis(9,9- dihexyl-9H-fluoren-2-yl)-5,6,7,8-tetrafluoroquinoxaline (F4Py), which are fluorene molecular derivatives with conjugated structure, were investigated. For further investigation of the influences of fluorine auxochrome in fluorene molecular electroluminescent material on optoelectronic property, the elec- troluminescence (EL) characteristics of materials were studied by double-layer organic light-emitting diodes (OLEDs) using N,N'-Di-[(1-naphthalenyl)-N,N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (NPB) as a hole transporting layer (HTL) with the conventional vacuum deposition method. The results showed that the absorption and PL spectra of materials in film state red shifted with fluorine substituents in- creased in molecule configuration. The performance of OLEDs is as follows: at a bias voltage of 5 V, Py emitted a blue-green light at 508 nm with the Commission Internationale d'Eclairage (CIE) coordinates of (0.23, 0.43) and full width at half maximum (FWHM) of 100 nm. The device had a turn-on voltage (de- fined as the drive voltage at the luminance of 1 cd/m2) of 4.8 V, a luminance of 129 cd/m2 with a current density of 59 mA/cm2 at 10 V, and a maximum luminous efficiency of 0.18 lm/W at 5.4 V. F2Py and F4Py emitted a green light peaking at 544 nm and a yellow light at 570 nm at 5 V, with the CIE coordinates of (0.38, 0.56) and (0.44, 0.49), and FWHM of 103 and 117 nm, respectively. The F2Py and F4Py devices had a turn-on voltage of 4 and 2 V, a luminance of 557 and 3300 cd/m2 with a current density of 100 and 880 mA/cm2 at 10 V, and a maximum luminous efficiency of 0.22 lm/W at 7.6 V and 0.53 lm/W at 2 V, respectively. | LOU ShuangLing YU dunSheng JIANG YaDong GUO GuoJun ZHANG Qing | 2008 | Chinese Science Bulletin2008，53，19： | 5 |
| 2 | Matched Field Localization Based on CS-MUSIC Algorithm显示文摘The problem caused by shortness or excessiveness of snapshots and by coherent sources in underwater acoustic positioning is considered.A matched field localization algorithm based on CS-MUSIC(Compressive Sensing Multiple Signal Classification) is proposed based on the sparse mathematical model of the underwater positioning.The signal matrix is calculated through the SVD(Singular Value Decomposition) of the observation matrix.The observation matrix in the sparse mathematical model is replaced by the signal matrix,and a new concise sparse mathematical model is obtained,which means not only the scale of the localization problem but also the noise level is reduced;then the new sparse mathematical model is solved by the CS-MUSIC algorithm which is a combination of CS(Compressive Sensing) method and MUSIC(Multiple Signal Classification) method.The algorithm proposed in this paper can overcome effectively the difficulties caused by correlated sources and shortness of snapshots,and it can also reduce the time complexity and noise level of the localization problem by using the SVD of the observation matrix when the number of snapshots is large,which will be proved in this paper. | GUO Shuangle TANG Ruichun PENG Linhui JI Xiaopeng | 2016 | Journal of Ocean University of China2016，15，2： | 1 |
| 4 | Numerical Simulation for Moving Contact Line with Continuous Finite Element Schemes显示文摘In this paper,we compute a phase field(diffuse interface)model of CahnHilliard type for moving contact line problems governing the motion of isothermal multiphase incompressible fluids.The generalized Navier boundary condition proposed by Qian et al.[1]is adopted here.We discretize model equations using a continuous finite element method in space and a modified midpoint scheme in time.We apply a penalty formulation to the continuity equation which may increase the stability in the pressure variable.Two kinds of immiscible fluids in a pipe and droplet displacement with a moving contact line under the effect of pressure driven shear flow are studied using a relatively coarse grid.We also derive the discrete energy law for the droplet displacement case,which is slightly different due to the boundary conditions.The accuracy and stability of the scheme are validated by examples,results and estimate order. | Yongyue Jiang Ping Lin Zhenlin Guo Shuangling Dong | 2015 | Communications in Computational Physics2015，18，6： | 0 |
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