Shantou UniversityGuangdong

Shantou, China

Shantou UniversityGuangdong

Shantou, China
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He D.,Shantou UniversityGuangdong | Yuan Y.,Shantou UniversityGuangdong | Yuan Y.,City University of Hong Kong | Liu B.,Shantou UniversityGuangdong | And 5 more authors.
Dyes and Pigments | Year: 2017

A novel near ultraviolet (NUV) emitter, PIBCz, was designed and synthesized by attaching C3-position of the weak electron-donating N-phenylcarbazole group to C6- and C9-positions of phenanthroimidazole (PI) unit for limiting the molecular conjugation and intramolecular charge transfer (ICT) process. The new emitter exhibits strong NUV emission both in solution and thin film as well as good thermal and morphological stability. The PIBCz-based non-doped device shows a perfect color purity of CIE (0.15, 0.05), a very low turn-on voltage of 2.7 V and a maximum external quantum efficiency (EQE), current efficiency (CE) and power efficiency (PE) of 2.74%, 1.28 cd A−1 and 1.12 lm W−1, respectively, which is comparable to state-of-the-art non-doped OLEDs in similar color gamut. This work demonstrates that effective management of ICT process is a valuable strategy to develop high efficiency NUV emitters. © 2016

Zhuang Z.,Shantou UniversityGuangdong | Li F.,Shantou UniversityGuangdong | Yuan Y.,Shantou UniversityGuangdong
Communications in Computer and Information Science | Year: 2017

A novel method based on distributed adaptive deflection projected subgradient is proposed in this paper. By used of attenuation model of a gas source in wind field, the method is able to process the distributed information from sensors by using the developed algorithm, replace the original gradient direction with deflection subgradient direction, and utilize the deflected subgradient projection hyperplanes as the searching areas in the process of relaxed projection, so as to obtain the gas source position. A related simulation provided in the paper illustrates that this method can not only provide good convergence property and accurate localization results, but also save large amount of energy. © Springer Nature Singapore Pte Ltd. 2017.

Zhu Z.-L.,Shantou UniversityGuangdong | Zhu Z.-L.,City University of Hong Kong | Ni S.-F.,South University of Science and Technology of China | Chen W.-C.,City University of Hong Kong | And 5 more authors.
Dyes and Pigments | Year: 2017

To increase the fluorescence quantum yield of hybrid local and charge-transfer (HLCT) material, we introduce a symmetric linear D-π-A-π-D structure into molecular design and synthesized a new blue emitter, 2,2'-(2′,3′,5′,6'-tetrafluoro-[1,1':4′,1″-terphenyl]-4,4″-diyl)bis(1-(4-(tert-butyl)phenyl)-1H-phenanthro[9,10-d]imidazole) (4FBTPI). Organic light-emitting devices employing 4FBTPI as a dopant emitter show good performances, with CIE (Commission Internationale de l'Enclairage) coordinates of (0.15, 0.09), which is very close to NTSC blue light standard (0.14, 0.08), current efficiencies (CE) of 6.03 cd A−1, external quantum efficiencies of 6.94%. This performance is comparable to those of recently reported state-of-the-art deep-blue materials with CIEy < 0.10. © 2017 Elsevier Ltd

Xu L.,Shantou UniversityGuangdong | Zhang D.,South China University of Technology | Zhou Y.,University of Melbourne | Zheng Y.,Shantou UniversityGuangdong | And 3 more authors.
Optical Materials | Year: 2017

In this paper, mono- and di-4-N,N-bis(4-methoxylphenyl)aniline-substituted anthraquinone have been designed and synthesized through Suzuki reaction. For mono-4-N,N-bis(4-methoxylphenyl)aniline-substituted anthraquinone, polymorphous crystal structures have been obtained in different crystallization conditions. Electrochemical characterization combined with theoretical calculation suggests that the addition of a second triphenylamine unit causes a larger band gap with higher lying LUMO (Lowest Unoccupied Molecular Orbital) and HOMO (Highest Occupied Molecular Orbital). The linear optical property shows that the introduction of a second triphenylamine unit bring about a significant hyperchromic effect with the extinction coefficients increasing from 11199 M−1 cm−1 to 22136 M−1 cm−1. The third-order nonlinear optical properties indicate that the introduction of a second triphenylamine unit lead to a much larger nonlinear absorption coefficient and two-photon absorption cross section, with the relevant value increasing from 2.04 × 10−12 cm W−1 to 3.91 × 10−12 cm W−1, and from 148 GM to 286 GM, respectively. © 2017 Elsevier B.V.

Cao L.,Shantou UniversityGuangdong | Xu L.,Shantou UniversityGuangdong | Zhang D.,South China University of Technology | Zhou Y.,University of Melbourne | And 4 more authors.
Chemical Physics Letters | Year: 2017

To study the relationship between donor (D)-acceptor (A) structures and the third-order nonlinear optical property, two types of D-A and D-A-D structures based on triphenylamine-substituted chromophores with benzanthrone or perylene diimide (PDI) acceptors have been designed and synthesized. Among them, D-A-D type chromophores with a linear configuration show relatively larger two-photon absorption (2 PA) coefficient and 2 PA cross section value. © 2017 Elsevier B.V.

Shen M.F.,Shantou Polytechnic | Su Z.F.,Shantou UniversityGuangdong
Applied Mechanics and Materials | Year: 2014

In this paper we present a compound anisotropic diffusion filter algorithm to apply edge sensitive ICOV operator in NCD model. According to the correlation coefficient of the ICOV operator, we obtain effective nonlinear denoising. The experiment have validated that our algorithm have better effect in smoothing and better ability in edge preservation. © (2014) Trans Tech Publications, Switzerland.

Shen M.F.,Shantou Polytechnic | Huang F.,Shantou UniversityGuangdong
Applied Mechanics and Materials | Year: 2014

Currently,the ultrasound image has been widely used in diagnosis and treatment of clinical medicine,the results obtained by the diagnostic accuracy and reliability of the image is directly related to the effects of diagnosis and treatment.Because ultrasound images in the imaging process inevitably contaminated noise,thus the research of inhibiting ultrasound image noise is one of the important issues in domestic and international ultrasound imaging techniques.This paper studies the multi-scale analysis and wavelet thresholding two theories,put forwarda denoising algorithm about combining the Nonsubsampling contourlet transform and a new threshold function,experiments show that the new algorithm can not only good at suppressing the noise of ultrasound images,and can better retain image edge and texture details. © (2014) Trans Tech Publications, Switzerland.

Lin H.,Shantou UniversityGuangdong | Lin H.,Digital Signal | Fan Z.,Shantou UniversityGuangdong | Fan Z.,Digital Signal | And 9 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

This paper presents a novel multiobjective constraint handling approach, named as MOEA/D-CDP-ID, to tackle constrained optimization problems. In the proposed method, two mechanisms, namely infeasibility driven (ID) and constrained-domination principle (CDP) are embedded into a prominent multiobjective evolutionary algorithm called MOEA/D. Constraineddomination principle defined a domination relation of two solutions in constraint handling problem. Infeasibility driven preserves a proportion of marginally infeasible solutions to join the searching process to evolve offspring. Such a strategy allows the algorithm to approach the constraint boundary from both the feasible and infeasible side of the search space, thus resulting in gaining a Pareto solution set with better distribution and convergence. The efficiency and effectiveness of the proposed approach are tested on several well-known benchmark test functions. In addition, the proposed MOEA/D-CDP-ID is applied to a real world application, namely design optimization of the two-stage planetary gear transmission system. Experimental results suggest that MOEA/D-CDP-ID can outperform other state-of-the-art algorithms for constrained multiobjective evolutionary optimization. © Springer International Publishing Switzerland 2014.

Sun L.,Shantou UniversityGuangdong | Su Z.,Shantou UniversityGuangdong | Shen M.,Shantou Polytechnic
WIT Transactions on Information and Communication Technologies | Year: 2014

Modeling of clinical electroencephalography (EEG) signals is an important problem in clinical diagnosis of brain diseases. The method using support vector machine (SVM) based on the structure risk minimization provides us an effective kind of learning machine. But solving the quadratic programming problem for training SVM becomes a bottle-neck of using SVM because of the long time of SVM training. In this paper, a local-SVM method is proposed for modeling EEG signals. The local method is presented for improving the speed of the prediction of EEG signals. Furthermore, this proposed model is used to detect epilepsy from EEG signals in which dynamic characteristics are different between normal and epilepsy EEG signals. The experimental results show that the training of the local-SVM obtains a good behavior. In addition, the local SVM method significantly improves the prediction and detection precision. © 2014 WIT Press.

Zhu Z.-L.,Shantou UniversityGuangdong | Zhu Z.-L.,City University of Hong Kong | Chen M.,Shantou UniversityGuangdong | Chen M.,City University of Hong Kong | And 7 more authors.
Organic Electronics: physics, materials, applications | Year: 2016

By using molecular twisting and bulky side group substitution, we successfully develop two deep-blue emitters, BiPI-1 and BiPI-2. These two twisted linear molecules retain the excellent photophysical and electrical properties of planar analogue and remarkably supress redshifts in solid state emission. Especially, BiPI-1 showed deep-blue emission in both solution and solid phase, and high carrier mobilities with μh > 10−3 cm2 V−1 s−1 and μe > 10−5 cm2 V−1 s−1. Standard blue electroluminescence (color purity: (0.15, 0.08)) and high device efficiency (CE: 4.62 cd A−1, EQE: 6.18%) were observed in a non-doped OLED of BiPI-1. © 2016 Elsevier B.V.

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