http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Dup (검색결과 12 건)
- 무료
- 기관 내 무료
- 유료
-
Du, P.,Luo, L.,Yu, J. S. Springer-Verlag 2017 Mikrochimica acta Vol.184 No.8
<P>The authors have synthesized Er(III)-doped BiOCl microplates by a solid-state reaction method. Under irradiation with 980 nm light, the microplates emit both green and red upconversion emissions originating from the transitions of Er(III) ions. By properly adjusting the concentration of the Er(III) ions, the colors can be tuned from pure green to yellowish green. The optimal doping concentration is 3 mol%. Furthermore, the ratio of the two green emission bands of the Er(III) ions is strongly temperature-dependent. The doped microplates can be used to sense temperature in the 298 to 778 K range, indicating a maximum sensitivity of 2.8 x 10(-3) K-1. The sensitivity is independent of Er(III) ion concentration. The internal heating properties of the microplates induced by the laser excitation are also discussed. Theoretical analysis reveals that the temperature of the doped BiOCl microplates increases from 276 to 324 K with elevating the laser power from 246 to 445 mW.</P>
-
Du, P.,Wu, S.,Yu, J.S. Elsevier [etc.] 2016 Journal of luminescence Vol.173 No.-
<P>Color-tunable CaWO4:0.05Dy(3+)/xEu(3+) phosphors were synthesized via a solid-state reaction method and the electronic properties of CaWO4 host lattice were analyzed through density function theory calculation. Under the excitations of 250 and 351 nm, characteristic emissions corresponding to D-5(0)-> F-4(J) (J=0, 1, 2) transitions of Eu3+ ions and characteristic blue and yellow emissions corresponding to (F9/2 -> H15/2)-F-4-H-6 and F-4(9/2)-> H-6(13/2) transitions of Dy3+ ions, respectively, were observed in all the Dy3+/Eu3+ ions codoped CaWO4 phosphors. The photoluminescence spectra and decay curves revealed that there existed an energy transfer from Dy3+ to Eu3+ ions and this was certified to be a resonant type via a dipole-dipole interaction. Furthermore, color-tunable emissions were observed by adjusting the relative content between Dy3+ and Eu3+ ions and the excitation wavelength. In addition, the Dy3+/Eu3+ ions codoped CaWO4 phosphors exhibited strong cathodoluminescence properties and their emission intensity increased with the increment of accelerating voltage from 1 to 5 kV and filament current from 34 to 55 mu A. (C) 2016 Elsevier B.V. All rights reserved.</P>
-
Du, P.,Luo, L.,Yu, J.S. Elsevier 2015 CURRENT APPLIED PHYSICS Vol.15 No.12
Er<SUP>3+</SUP>/Yb<SUP>3+</SUP>-codoped SrMoO<SUB>4</SUB> phosphors were prepared by a high-temperature solid-state reaction method. At room temperature, all the as-prepared samples exhibited strong upconversion properties and the emission intensity increased dramatically with the increase of Yb<SUP>3+</SUP> ion concentration, reaching its maximum value when the concentration was 5 mol%. The dependence of emission intensity on the pump power suggested that the upconversion emission was a two-photon process. Furthermore, the optical temperature sensing properties based on green upconversion emissions of the SrMoO<SUB>4</SUB>:0.01Er<SUP>3+</SUP>/0.05Yb<SUP>3+</SUP> phosphor were studied. It is found that the SrMoO<SUB>4</SUB>:0.01Er<SUP>3+</SUP>/0.05Yb<SUP>3+</SUP> phosphor can be operated over a very wide temperature range of 93-773 K with a maximum sensitivity of ~0.0128 K<SUP>-1</SUP>, indicating that low- and high-temperature thermometry can be simultaneously realized in this phosphor.
-
Hydrodynamics prediction of a ship in static and dynamic states
Du, P.,Ouahsine, A.,Sergent, P. Techno-Press 2018 Coupled systems mechanics Vol.7 No.2
The ship hydrodynamics in static and dynamic states were investigated using 3-dimensional numerical simulations. The static case simulated a fixed ship, while the dynamic case considered a ship with free sinkage and trim using the mesh morphing technique. High speed was found to increase the wave elevation around the ship. Compared with the static case, the dynamic case seemed to generate higher waves near the bow and after the stern. The frictional resistance was found be to more dominant. However, the pressure resistance became gradually important with the increase of the ship speed. The trim and sinkage were also analyzed to characterize the ship hydrodynamics in the dynamic state.
-
Fibroblast-derived matrix (FDM) as a novel vascular endothelial growth factor delivery platform
Du, P.,Hwang, M.P.,Noh, Y.K.,Subbiah, R.,Kim, I.G.,Bae, S.E.,Park, K. Elsevier Science Publishers 2014 Journal of controlled release Vol.194 No.-
Vascular endothelial growth factor (VEGF) is one of the most important signaling cues during angiogenesis. Since many delivery systems of VEGF have been reported, the presentation of VEGF using a more physiologically relevant extracellular matrix (ECM), however, has yet to be thoroughly examined. In this study, we propose that fibroblast-derived extracellular matrix (FDM) is a novel platform for angiogenic growth factor delivery and that FDM-mediated VEGF delivery can result in an advanced angiogenic response. The FDMs, activated by EDC/NHS chemistry, were loaded with varying amounts of heparin. Different doses of VEGF were subsequently immobilized onto the heparin-grafted FDM (hep-FDM); 19.6+/-0.6, 39.2+/-3.2, and 54.8+/-8.9ng of VEGF were tethered using 100, 300, and 500ng of initial VEGF, respectively. VEGF-tethered FDM was found chemoattractive and VEGF dose-dependent in triggering human umbilical vein endothelial cells (ECs) migration in vitro. When hep-FDM-bound VEGF (H-F/V) was encapsulated into alginate capsules (A/H-F/V) and subjected to release test for 28days, it exhibited a significantly reduced burst release at early time point compared to that of A/V. The cell proliferation results indicated a substantially extended temporal effect of A/H-F/V on EC proliferation compared to those treated with soluble VEGF. For a further study, A/H-F/V was transplanted subcutaneously into ICR mice for up to 4weeks to assess its in vivo effect on angiogenesis; VEGF delivered by hep-FDM was more competitive in promoting blood vessel ingrowth and maturation compared to other groups. Taken together, this study successfully engineered an FDM-mediated VEGF delivery system, documented its capacity to convey VEGF in a sustained manner, and demonstrated the positive effects of angiogenic activity in vivo as well as in vitro.
-
Du, P.,Yu, J.S. Elsevier [etc.] 2016 Journal of luminescence Vol.179 No.-
A series of Eu<SUP>3+</SUP>-activated Na<SUB>0.5</SUB>Gd<SUB>0.5</SUB>MoO<SUB>4</SUB> phosphors were prepared by a typical sol-gel method. The as-prepared samples possessed a single tetragonal phase and consisted of closely-packed particles. Under the excitation of 395nm, all the phosphors exhibited the characteristic emissions of Eu<SUP>3+</SUP> ions corresponding to the <SUP>5</SUP>D<SUB>0</SUB>→ <SUP>7</SUP>F<SUB>J</SUB> transitions. The photoluminescence (PL) emission intensities were enhanced with the increment of Eu<SUP>3+</SUP> ion concentration and the optimum doping concentration was 0.25mol. The energy transfer mechanism between the Eu<SUP>3+</SUP> ions was dominated by dipole-dipole interaction and the critical distance was found to be 8.45A. Furthermore, the temperature-dependent PL emission spectra suggested that the obtained phosphors had good thermal stability (60.4% of the initial intensity at 150<SUP>o</SUP>C). In addition, the color purity, chromatic and cathodoluminescence (CL) properties of the Na<SUB>0.5</SUB>Gd<SUB>0.5</SUB>MoO<SUB>4</SUB>:0.25Eu<SUP>3+</SUP> phosphor were also investigated. The results indicated that the Eu<SUP>3+</SUP>-activated Na<SUB>0.5</SUB>Gd<SUB>0.5</SUB>MoO<SUB>4</SUB> phosphors with excellent PL and CL properties may have potential applications in white light-emitting diodes and field-emission displays.
-
Du, P.,Luo, L.,Yu, J.S. Ceramurgica ; Elsevier Science Ltd 2016 CERAMICS INTERNATIONAL Vol.42 No.5
A series of Yb<SUP>3+</SUP> ions sensitized NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:Er<SUP>3+</SUP> phosphors were synthesized through a solid-sate reaction method. The X-ray diffraction (XRD), upconversion (UC) emission and cathodoluminescence (CL) measurments were applied to characterize the as-prepared samples. Under the excitation of 980nm light, bright green UC emissions corresponding to (<SUP>2</SUP>H<SUB>1½</SUB>,<SUP>4</SUP>S<SUB>3/2</SUB>)→<SUP>4</SUP>I<SUB>15/2</SUB> transitions of Er<SUP>3+</SUP> ions were observed and the UC emission intensities showed an upward trend with increasing the Yb<SUP>3+</SUP> ion concentration, achieving its optimum value at 25mol%. Furthermore, the temperature sensing behavior based on the thermally coupled levels (<SUP>2</SUP>H<SUB>1½</SUB>,<SUP>4</SUP>S<SUB>3/2</SUB>) of Er<SUP>3+</SUP> ions was analyzed by a fluorescence intensity ratio technique. It was found that the obtained samples can be operated in a wide temperature range of 133-773K with a maximum sensitivity of approximately 0.0112K<SUP>-1</SUP> at 515K. Ultimately, strong CL properties were observed in NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:0.01Er<SUP>3+</SUP>/0.25Yb<SUP>3+</SUP> phosphors and the CL emission intensity increased gradually with the increment of accelerating voltage and filament current.
-
-
Du, P.,Yu, J.S. Elsevier 2017 CURRENT APPLIED PHYSICS Vol.17 No.12
<P>The Eu3+-activated NaYF4 nanocrystals were synthesized via a facile hydrothermal technique. The resultant compounds were characterized by X-ray diffraction pattern, transmission electron microscope images and photoluminescence (PL)/cathodoluminescence (CL) spectra. Under near-ultraviolet light excitation, the characteristic emissions of Eu3+ ions were detected in the prepared nanocrystals and the red emission at 615 nm originating from the D-5(0) -> F-7(2) transition dominated in the emission spectrum. The luminescent spectrum revealed that the Eu3+ ions populated the low symmetry sites in NaYF4 lattices. Furthermore, a theoretical calculation based on the Judd-Ofelt theory was performed to evaluate the intensity parameters to further explore the local structure environment surrounding Eu3+ ions in NaYF4 lattices. The temperature-dependent PL emission spectra were recorded to study the thermal stability of the resultant nanocrystals and the activation energy was determined to be 0.149 eV. Ultimately, the CL properties of the final products as a function of accelerating voltage and filament current were investigated. These results revealed that the synthesized nanocrystals are a promising candidate for white light-emitting diodes and field emission displays as red-emitting phosphors. (C) 2017 Elsevier B.V. All rights reserved.</P>
-
Synthesis and luminescent properties of red-emitting Eu3+-activated Ca0.5Sr0.5MoO4 phosphors
Du, P.,Yu, J. S. Springer Science + Business Media 2016 JOURNAL OF MATERIALS SCIENCE - Vol.51 No.11
<P>Eu3+-activated Ca0.5Sr0.5MoO4 phosphors were prepared by a high-temperature solid-state reaction method. The X-ray diffraction patterns revealed that the obtained samples had a pure tetragonal phase. Under 393 nm excitation, all the samples exhibited the characteristic emissions of Eu3+ ions and the photoluminescence (PL) emission intensities showed an upward trend with elevating the Eu3+ ion concentration, while the concentration quenching effect took place when the Eu3+ ion concentration was over 9 mol% and the critical distance was determined to be about 13.09 a'<<. Furthermore, the cathodoluminescence (CL) spectra, which were measured under low-voltage electron-beam excitation, demonstrated that the Ca0.41Sr0.5MoO4:0.09Eu(3+) phosphor had excellent CL performance. Also, the alkali metal ions, such as Li+, Na+, and K+, were used as the charge compensator to modify the PL emission intensity of the Ca0.41Sr0.5MoO4:0.09Eu(3+) phosphor and the phosphor compensated by Na+ ions showed the strongest PL emission intensity.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
