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Han Z.,Fuzhou University | Wei L.,Fuzhou University | Tang L.,Fuzhou University | Tang L.,Fujian Key Laboratory of Medical Instrument and Pharmaceutical Technology | And 4 more authors.
Journal of Power Sources | Year: 2013

The large bandgap of ZnO limits its application in photovoltaic devices, thus the semiconductor quantum dots (QDs), such as CdSe, is utilized to improve light-harvesting efficiency of solar cells. The CdSe@ZnO flower-rod core-shell nanocable arrays (CSZFRs) are prepared with a simple ion exchange method from aqueous solutions. The optical absorptions of the nanocable arrays can be controllably tuned to cover almost the entire visible spectrum (>750 nm) via quantum dots (QDs) sensitized attributed to the smaller band gap of CdSe. Moreover, a typical type II band alignment enhance the separation of photogenerated charge carriers, and reduce the electron-hole recombination within CSZFRs, demonstrated by the photoluminescence (PL) quenching after the formation of CSZFR hybrid structures. In addition, the CdSe-sensitized ZnO nanostructures demonstrate broad external quantum efficiency (EQE) in the spectrum from 300 to 740 nm. Therefore, the CSZFRs nanocable heterostruture exhibits a photovoltaic performance with a higher open-circuit photovoltage (-0.93 VAg/AgCl) and short-circuit photocurrent (1.00 mA cm -2). © 2013 Elsevier B.V. All rights reserved.


Yao H.,Fuzhou University | Zhong S.,Fuzhou University | Zhong S.,Fujian Key Laboratory of Medical Instrument and Pharmaceutical Technology
Optics Express | Year: 2014

We report terahertz surface plasmon resonance (SPR) sensing based on prism-coupling to the spoof surface plasmon polariton (SSPP) mode existing on periodically grooved metal films. It was demonstrated that, except for the fundamental mode of the SSPP, there was also a higher mode SSPP wave when the depth of groove was larger. Both fundamental and high-order modes of SSPP could be used for terahertz sensing. We compared the performance of different modes of SSPP on the sensing sensitivity using both reflection amplitude and phase-jump information. The results indicated that the gap distance between the prism base and the metal film had a significant influence on the reflectivity of SPR sensing by affecting the coupling efficiency of an evanescent wave to an SSPP wave; also, high-order mode SSPP-based sensing had a high sensitivity of up to 2.27 THz/RIU, which nearly doubled the sensitivity of the fundamental mode. The application of high-mode SSPP has enormous potential for ultra-sensitive SPR sensing in the terahertz regime. © 2014 Optical Society of America.


Yao H.-Z.,Fuzhou University | Zhong S.,Fuzhou University | Zhong S.,Fujian Key Laboratory of Medical Instrument and Pharmaceutical Technology
IEEE Photonics Journal | Year: 2015

We report the characteristics of a right-handed helically grooved metal wire waveguide. For the helically grooved waveguide, the normal degenerate HE1 spoof surface plasmon polariton (SSPP) mode could be decomposed into two opposite circularly polarized modes, i.e., HE-1 and HE+1 SSPP modes, due to the chirality of helical grooves. The dispersion characteristics of the nondegenerate HE ± 1 SSPP modes were numerically obtained, and their spiral electromagnetic distributions were also presented. It was found that the HE ± 1 modes were circularly polarized; they were also vortex modes and possessed an orbit angular monument. In addition, the focusing characteristics of such waves near the waveguide end were investigated. The distinct advantages, such as a relatively long focusing length and the circular polarization of the chiral HE + 1 SSPP modes, make the helically grooved metal wire waveguide a potential for near-field circular dichroism detection. © 2009-2012 IEEE.


Zhong J.,Fuzhou University | Zhong S.,Fuzhou University | Zhong S.,Fujian Key Laboratory of Medical Instrument and Pharmaceutical Technology | Zhang Q.,Fuzhou University | Yao L.,Fuzhou University
Optics and Lasers in Engineering | Year: 2015

We present a two-dimensional optical coherence vibration tomography (2DOCVT) system with an ultra-precision displacement resolution of ~0.1 nm that is capable of in site real-time absolute displacement measurement of structural line vibrations. Experimental results of sinusoidal, sweep and impulse vibrations were reported. The key figures of merit such as the 2DOCVT system could obtain fast line vibration measurement without scanning and it also could be used to capture structural modal parameters in one single impulse excitation measurement without any vibration excitation input information, making it attractive for the application in low-frequency vibration measurement and response-only modal analysis. © 2014 Elsevier Ltd.


Yao H.,Fuzhou University | Zhong S.,Fuzhou University | Zhong S.,Fujian Key Laboratory of Medical Instrument and Pharmaceutical Technology
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2014

The spoof surface plasmon polariton (SPP) effect on the electromagnetic field distribution near the tip of a periodically corrugated metal cylinder-cone probe working at the terahertz regime was studied. We found that radially polarized terahertz radiation could be coupled effectively through a spoof SPP into a surface wave and propagated along the corrugated surface, resulting in more than 20× electric field enhancement near the tip of probe. Multiple resonances caused by the antenna effect were discussed in detail by finite element computation and theoretical analysis of dispersion relation for spoof SPP modes. Moreover, the key figures of merit such as the resonance frequency of the SPP can be flexibly tuned by modifying the geometry of the probe structure, making it attractive for application in an apertureless background-free terahertz near-field microscope. © 2014 Optical Society of America.


Luo M.,Fuzhou University | You T.,Fuzhou University | Zhang Q.,Fuzhou University | Zhong J.,Fuzhou University | And 2 more authors.
Journal of Applied Optics | Year: 2015

Based on the balanced detection and stationary wavelet transform (SWT) algorithm, a broadband low coherent white light source with center wavelength of 700 nm was employed to set up a time-domain optical coherence tomography (TDOCT) system in free space. The resolution of the developed OCT system was down to 0.93 μm and it was applied to nondestructive evaluation of plastic sheets and transparent-tape multi-layered thin-film structures. The imaging enhancement methods in the process of OCT images were compared. To resolve the problem of unsatisfactory reconstruction results using current algorithms, the SWT decomposition algorithm was introduced to deal with the OCT images of the multi-layered structures. The experimental results show that this SWT-based method could extract more distinct interface interference signal from the SWT detail coefficients and therefore the interface imaging quality of multi-layered structures could be enhanced. ©, 2015, Editorial Board, Journal of Applied Optics. All right reserved.


Bai K.-K.,Fuzhou University | Yu Z.,Fuzhou University | Chen F.-L.,Fuzhou University | Li F.,Fuzhou University | And 3 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2012

Structural modification was performed at the C-3 and C-28 positions of ursolic acid (UA). Ten UA derivatives with distinct electrical property were synthesized. They could be divided into two groups according to their charge under physiological conditions: (1) Group I negatively charged and (2) Group II positively charged. The anti-proliferative capability of the derivatives was evaluated against HepG2, AGS, HT-29 and PC-3 cells by the MTT assay. Flow cytometry and Annexin V/PI dual staining assay were carried out to explore the antitumor mechanism. The results showed the cytotoxic capacity of the compounds was: Group I < UA < Group II. The UA derivatives in Group II exhibited potent cytotoxicity and the enhancement of the lipophilicity could further strengthen the cytotoxicity. Triggering apoptosis and causing cell cycle arrest contributed to the anticancer mechanism. The UA derivative UA-7 had the therapeutic potential in the treatment of gastric carcinoma since it showed potent cytotoxicity, reasonable oil/water partition, enhanced water solubility, and the ability to induce the apoptosis of AGS cells. © 2011 Elsevier Ltd. All rights reserved.


Han Z.,Fuzhou University | Liao L.,Fuzhou University | Wu Y.,Fuzhou University | Wu Y.,Fujian Key Laboratory of Medical Instrument and Pharmaceutical Technology | And 4 more authors.
Journal of Hazardous Materials | Year: 2012

An oriented hierarchical ZnO flower-rod arrays (FRs) were prepared on indium doped tin oxide (ITO) glass using a facile solution-based method assisted with ZnO seed layer. And the as-prepared ZnO FRs/ITO was used as a convenient photocatalytic device that recycled without centrifugation. The results show that ZnO FRs are wurtzite phase with single crystalline grown along the [0. 0. 1] direction. The photoluminescence (PL) spectra illustrate that there are more oxygen vacancies on the surface of ZnO FRs compared with ZnO nanoparticles (NPs). The electrochemical methods using Rhodamine B (RhB) as electrolyte are also performed to study on the photodegradation mechanism where RhB is acted as photocatalytic substrate. For ZnO FRs, the higher photoinduced currents under UV irradiation and current density prove that the recombination of electron-hole pairs is restrained with oxygen vacancies, and the lower charge transfer resistance suggest that the charges could move quickly through ZnO oriented structures. Therefore, the photocatalytic activity is enhanced by ZnO FRs compared with ZnO NPs, and RhB degradation efficiency of ZnO FRs photocatalysts is nearly 100% by UV irradiation for 1.5. h. © 2012 Elsevier B.V.


Bai K.-K.,Fuzhou University | Chen F.-L.,Fuzhou University | Yu Z.,Fuzhou University | Zheng Y.-Q.,Fuzhou University | And 3 more authors.
Bioorganic and Medicinal Chemistry | Year: 2011

Ursolic acid (UA) as the leader compound was designed to prepare a series of derivatives (three novel compounds UA-1a, UA-1b and UA-2) by modification at the C3 and C28 positions. Their chemical structures were confirmed by IR, 1H NMR and MS. The cytotoxic activity of the derivatives was evaluated against HepG2, BGC-823 and HT-29 by the MTT assay. The novel derivative UA-1a, [3β-acetoxy-urs-12-en-28-oyl]-1-monoglyceride showed significant anti-growth ability against the assayed cancer cell lines, particularly against BGC-823, while low cytotoxicity to human normal gastric cell line GES-1. Further investigation revealed that UA-1a could induce apoptotic events of the treated BGC-823 cells, such as comet-like DNA bend, sub-G0/G1 phase accumulation and phosphatidylserine externalization. The activity of Caspase-3 was found to be up-regulated, while the expression of Bcl-2 and Survivin were down-regulated in UA-1a treated cells. UA-1a might trigger the death of BGC-823 cells by inducing apoptosis via the mitochondria pathway. UA-1a exerted stronger ability than Taxol to retard tumor growth in nude mice without leaving apparent toxicity to the hosts. The experimental data suggested that UA-1a would have a therapeutic potential in the treatment of gastric cancer. © 2011 Elsevier Ltd. All rights reserved.


Han Z.,Fuzhou University | Wei L.,Fuzhou University | Zhang Z.,Fuzhou University | Zhang X.,Fuzhou University | And 3 more authors.
Plasmonics | Year: 2013

The semiconductor metal oxide, ZnO, is limited to application in photocatalysis because of large bandgap. Metallic nanostructures are utilized to enhance visible-light absorption and improve photocatalytic activity via surface plasmon resonance (SPR). In this work, through a facile thermal decomposition method, the Au nanoparticles (NPs) were successfully loaded on oriented hierarchical ZnO flower-rod (ZFRs) heterostructures, which have a higher areal proportion of exposed active (001) crystal faces. The results indicate that ZFRs are wurtzite phase grown along the [001] direction and the Au NPs spread on the surface of ZFRs in metallic form. It reveals that there is an electronic interaction between Au NPs and ZFRs, and more oxygen molecules are adsorbed on the surface of Au-ZnO flower-rod heterostructures (AZFRs). The AZFRs show a strong absorbance in visible region due to the SPR and enhance the separation of electron-hole pair, resulting in an improvement of photocatalytic activity under visible-light irradiation. During 80 min, the degradation efficiency of rhodamine B for AZFRs-20 is about 3.7 times as the pure ZFRs. Moreover, the AZFRs exhibit predominant photoelectrochemical properties, and the photocurrent can reach 1.2 × 10-4 A. Finally, the as-prepared photocatalytic device composed of AZFRs based on indium doped tin oxide glass is convenient to recycle without centrifugation. © 2013 Springer Science+Business Media New York.

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