Journal articles: 'Excitation uv'

1

OHTSUKA, Reiji. "UV and VUV Excitation Phoshors." JOURNAL OF THE ILLUMINATING ENGINEERING INSTITUTE OF JAPAN 82, Appendix (1998): 305. http://dx.doi.org/10.2150/jieij1980.82.appendix_305.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Pokhrel, M., G. A. Kumar, C. G. Ma, M. G. Brik, Brian W. Langloss, Ian N. Stanton, Michael J. Therien, D. K. Sardar, and Yuanbing Mao. "Electronic and optical properties of Er-doped Y2O2S phosphors." Journal of Materials Chemistry C 3, no. 43 (2015): 11486–96. http://dx.doi.org/10.1039/c5tc02665b.

Full text

Abstract:

Green light emitted from Y₂O₂S:1%Er phosphors after excited with NIR, UV and X-ray sources with emissions spectra under UV and NIR excitations (lower right) and X-ray excitation at different X-ray tube voltages (lower left).

APA, Harvard, Vancouver, ISO, and other styles

3

Librantz, André Felipe Henriques, Luiz Vicente Gomes Tarelho, Laércio Gomes, and Izilda Márcia Ranieri. "Study of UV fluorescences induced from 4f3 T 4f25d multistep absorptions of Nd3+ions in YLiF4 and LuLiF4 crystals." Exacta 4, no. 1 (March 12, 2008): 179–83. http://dx.doi.org/10.5585/exacta.v4i1.671.

Full text

Abstract:

Nd3+ ultraviolet (UV) fl uorescence induced by multiphotonic laser excitations was studied in doped Nd:YLiF4 (YLF) and Nd:LuLiF4 (LLF) crystals by using the time resolved spectroscopy technique. The UV luminescences are due to transitions between the 4f25d and the 4f3 electronic confi gurations of Nd3+ ions. The 4f25d confi guration can be reached by direct pumping or by multiphotonic excitation, both processes give rise to the UV band emission with structure due to the strong phonon coupling expected for 5d orbital involvement in the transition. The multiphotonic excitation process is due to three photons (532 nanometers [nm]) sequential absorptions by metastable levels of the 4f3 confi guration split by crystalline local fi eld. The sequential excitation of Nd by the laser excitation is attributed to the 4I9/2 + 532 nm T 4G7/2 ground state absorption followed by the 4G7/2 + 532 nm T 2F5/2 and 2F5/2 + 532 nm T 4f25d excited state absorptions. The UV emissions due to 4f25d confi guration are parity allowed, having lifetime of 35 nanoseconds (ns) in contrast to UV emissions from 4f3 confi guration which are induced by two absorption steps and are parity forbidden showing longer lifetime of 8 microseconds (ms) and narrow lines. The polarization effects of the UV emissions were studied and their behaviors are dependent on the excited state confi guration involving or not involving the 5d orbital. The allowed UV emission positions were affected by the host variation more than the ones originated from the 4f3 confi guration as expected. The electronic energy of the 4f25d confi guration shifts to lower energy for increasing the crystal fi eld.

APA, Harvard, Vancouver, ISO, and other styles

4

Librantz, André Felipe Henriques, Luiz Vicente Gomes Tarelho, Laércio Gomes, and Izilda Márcia Ranieri. "Study of UV fluorescences induced from 4f3 T 4f25d multistep absorptions of Nd3+ions in YLiF4 and LuLiF4 crystals DOI: 10.5585/exacta.v4i1.671." Exacta 4, no. 1 (March 12, 2008): 179–83. http://dx.doi.org/10.5585/exactaep.v4i1.671.

Full text

Abstract:

Nd3+ ultraviolet (UV) fl uorescence induced by multiphotonic laser excitations was studied in doped Nd:YLiF4 (YLF) and Nd:LuLiF4 (LLF) crystals by using the time resolved spectroscopy technique. The UV luminescences are due to transitions between the 4f25d and the 4f3 electronic confi gurations of Nd3+ ions. The 4f25d confi guration can be reached by direct pumping or by multiphotonic excitation, both processes give rise to the UV band emission with structure due to the strong phonon coupling expected for 5d orbital involvement in the transition. The multiphotonic excitation process is due to three photons (532 nanometers [nm]) sequential absorptions by metastable levels of the 4f3 confi guration split by crystalline local fi eld. The sequential excitation of Nd by the laser excitation is attributed to the 4I9/2 + 532 nm T 4G7/2 ground state absorption followed by the 4G7/2 + 532 nm T 2F5/2 and 2F5/2 + 532 nm T 4f25d excited state absorptions. The UV emissions due to 4f25d confi guration are parity allowed, having lifetime of 35 nanoseconds (ns) in contrast to UV emissions from 4f3 confi guration which are induced by two absorption steps and are parity forbidden showing longer lifetime of 8 microseconds (ms) and narrow lines. The polarization effects of the UV emissions were studied and their behaviors are dependent on the excited state confi guration involving or not involving the 5d orbital. The allowed UV emission positions were affected by the host variation more than the ones originated from the 4f3 confi guration as expected. The electronic energy of the 4f25d confi guration shifts to lower energy for increasing the crystal fi eld.

APA, Harvard, Vancouver, ISO, and other styles

5

Sweeney, Joyce A., and Sanford A. Asher. "Tryptophan UV resonance Raman excitation profiles." Journal of Physical Chemistry 94, no. 12 (June 1990): 4784–91. http://dx.doi.org/10.1021/j100375a009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Murgida, D. H., R. Erra-Balsells, and G. M. Bilmes. "New photocalorimetric references for UV excitation." Chemical Physics Letters 250, no. 2 (February 1996): 198–202. http://dx.doi.org/10.1016/0009-2614(95)01448-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Gorelik, V. S. "Pulsed uv excitation of biological structures." Journal of Russian Laser Research 20, no. 2 (March 1999): 152–70. http://dx.doi.org/10.1007/bf02508691.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Zheng, W. "Emission Lines in the Far-UV and Extreme-UV Region." International Astronomical Union Colloquium 159 (1997): 108–15. http://dx.doi.org/10.1017/s0252921100039750.

Full text

Abstract:

AbstractRecent observations with HST and HUT have been made of the spectral region shortward of Lyα in AGN. Emission lines in this region, such as O VIλ1035 and Ne VIIIλ774, are mainly produced by collisional excitation. Their strengths and the lack of other significant emission lines of higher excitation energy indicate a temperature of ~ 6 × 104 K for the highly ionized gas in line-emitting clouds. Model calculations suggest that the strength of O VI and Ne vIII emission is correlated to the intensity of the high-energy photons above 100 eV. Therefore, these lines are useful diagnostics of the continuum shape in the soft X-ray range. The luminosity dependence of emission-line equivalent widths is more prominent for lines of higher ionization level, suggesting that the UV bump in AGN spectra may be weaker at higher luminosities.

APA, Harvard, Vancouver, ISO, and other styles

9

Plewa, Julian, and T. Juestel. "Synthesis and Optical Characterization of Pr³⁺ Doped UV Emitting Luminescent Ceramics." Materials Science Forum 636-637 (January 2010): 344–47. http://dx.doi.org/10.4028/www.scientific.net/msf.636-637.344.

Full text

Abstract:

UV emitting luminescent materials are of strong interest for UV emitting fluorescent lamps driven by a Hg low-pressure or a by Xe excimer discharge. Pr3+ doped host lattices exhibit efficient UV emission upon deep UV excitation, if the site of the host lattice, where Pr3+ is located, is suitable for this purpose. This work deals with Pr3+ activated VUV ceramic luminophores, i.e. materials, which show efficient luminescence upon 160 nm excitation. As host lattices for the potentially UV emitting Pr3+ ion aluminates and silicates have been studied. All samples were prepared by conventional mix and fire synthesis techniques with metal oxides as starting materials. Firstly, powder samples were annealed between 1000 and 1700 °C and secondly, ceramic samples were repeatedly thermally treated at similar temperatures after pressing. It is demonstrated that translucent ceramics show mainly UV luminescence upon deep UV excitation, while excitation by a blue 450 nm LED results in green to red luminescence with a similar decay time as observed for single crystals.

APA, Harvard, Vancouver, ISO, and other styles

10

Wen, A. T., A. P. Hitchcock, N. H. Werstiuk, N. Nguyen, and W. J. Leigh. "Studies of electronic excited states of substituted norbornenes by UV absorption, electron energy loss, and HeI photoelectron spectroscopy." Canadian Journal of Chemistry 68, no. 11 (November 1, 1990): 1967–73. http://dx.doi.org/10.1139/v90-302.

Full text

Abstract:

Valence and inner-shell (C1s) electronic excitation spectra of norbornene, 2-methylnorbornene, and 2-trifluoromethylnorbornene have been measured by electron energy loss spectroscopy. These data have been complemented with gas- and solution-phase UV absorption spectra in the 5–6.7 eV range, HeI UV photoelectron spectra, and AM1 semi-empirical calculations for the three compounds. The valence shell energy loss and UV absorption spectra show marked variations throughout the series of compounds, suggesting the presence of at least three low-lying electronic excited states. The spectral bands have been assigned as due to π,R(3s), π,π*, and π, R(3p) excitations on the basis of their term values and the differences between their intensities in the solution and gas phase absorption spectra. The valence shell spectra indicate that while the vertically-excited π,R(3s) state is substantially lower in energy than the (vertically-excited) π,π* state in norbornene and the 2-methyl derivative, they are nearly isoenergetic in 2-trifluoromethylnorbornene. This difference in excited state manifolds is reflected in profound differences between the solution phase photochemistry of norbornene and the 2-trifluoromethyl derivative.The carbon 1s spectra are even more sensitive to substituent than the valence shell energy loss spectra. An interpretation is proposed which reflects the spatially localized character of inner-shell excitation and a "group orbitals" picture of the unoccupied MO's as accessed by C1s excitation. Keywords: Rydberg, electron energy loss, UV absorption, UV photoelectron spectroscopy, alkene, gas-phase.

APA, Harvard, Vancouver, ISO, and other styles

11

Wokosin, D., V. F. Centonze, and J. G. White. "UV-excited fluorophore images obtained with IR excitation." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 906–7. http://dx.doi.org/10.1017/s0424820100166993.

Full text

Abstract:

The widespread use of two-photon excitation fluorescence imaging has been somewhat inhibited by the necessity to use large, expensive, high-power, short-pulse lasers. These ultra-short pulse lasers are used as an excitation source in a raster scanning configuration to provide sufficient peak power density in a lens focal volume to generate detectable two-photon absorption events for rapid imaging. Biological studies often benefit from multiple fluorescent labels and multi-labelled samples often require different excitation wavelengths for adequate excitation of the various colored fluorophores. This is achieved inexpensively with the three Krypton Argon laser lines in standard confocal imaging systems, but multiple two-photon excitation lasers--if available-- would be a very expensive system. The lasers commonly used for two-photon imaging are tuneable, but this is not a non-trivial and time consuming process. The tuning range on these lasers allows good access to the blue-emitting and green-emitting fluorophores via two-photon excitation; however, we have found that a fixed-wavelength, compact,

APA, Harvard, Vancouver, ISO, and other styles

12

Levenson, Richard, Farzad Fereidouni, Zachary Harmany, Miao Tan, Mirna Lechpammer, and Stavros Demos. "Slide-Free Microscopy via UV Surface Excitation." Microscopy and Microanalysis 22, S3 (July 2016): 1002–3. http://dx.doi.org/10.1017/s1431927616005857.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Barbatti, Mario, Hans Lischka, Susanne Salzmann, and Christel M. Marian. "UV excitation and radiationless deactivation of imidazole." Journal of Chemical Physics 130, no. 3 (January 21, 2009): 034305. http://dx.doi.org/10.1063/1.3056197.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Johnson, Craig R., and Sanford A. Asher. "UV resonance Raman excitation profiles ofl-cystine." Journal of Raman Spectroscopy 18, no. 5 (August 1987): 345–49. http://dx.doi.org/10.1002/jrs.1250180509.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Moldovan, I. C., V. Fesquet, F. Marc, H. Guillet de Chatellus, and J. P. Pique. "Sodium UV modeless laser excitation for PLGS." Annales de Physique 32, no. 2-3 (2007): 91–93. http://dx.doi.org/10.1051/anphys:2008015.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Litfin, G., G. Heise, and H. Welling. "UV-laser excitation of color center lasers." Optics Communications 59, no. 2 (August 1986): 137–41. http://dx.doi.org/10.1016/0030-4018(86)90465-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Höfer, U., and E. Umbach. "Vibrational excitation in UV-photoemission of absorbates." Journal of Electron Spectroscopy and Related Phenomena 54-55 (January 1990): 591–600. http://dx.doi.org/10.1016/0368-2048(90)80251-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Dong, Yanwei, Ming Kang, Ping Zhang, Qijun Cheng, and Jie Wang. "Preparation and tunable luminescence of CaCO3:Eu3+,Dy3+ phosphors." Functional Materials Letters 07, no. 04 (August 2014): 1450038. http://dx.doi.org/10.1142/s1793604714500386.

Full text

Abstract:

Phosphors based on calcium carbonate, co-doped with various Eu 3+ and Dy 3+ concentrations were prepared by microwave co-precipitation method. The prepared phosphors were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry and differential scanning calorimetry (TG-DSC) and photoluminescence and photoluminescence excitation (PL-PLE) spectroscopy. Results showed that Dy 3+ and Eu 3+ ions were uniformly introduced into the host lattice of CaCO 3 taking the place of Ca 2+ ions. Under the excitation at 382 nm, the emission peak wavelengths were at 487 nm (4 F 9/2 → 6 H 15/2 of Dy 3+), 576 nm (4 F 9/2 → 6 H 13/2 of Dy 3+), and 614 nm (5 D 0 → 7 F 2 of Eu 3+). The luminescent intensities and emitting colors of Eu 3+- Dy 3+ co-doped CaCO 3 phosphors could be controlled by UV–violet excitations wavelengths or the rare-earth ions concentrations of Eu 3+ and Dy 3+ in phosphors. The chromaticity coordinates and photographs of samples under UV light showed the changes of the luminescence color intuitively through the varing UV–violet excitations wavelengths or the rare-earth ions concentrations of Eu 3+ and Dy 3+.

APA, Harvard, Vancouver, ISO, and other styles

19

Arnold, Bradley R., Christopher E. Cooper, Michael R. Matrona, Darren K. Emge, and Jeffrey B. Oleske. "Stand-off deep-UV Raman spectroscopy." Canadian Journal of Chemistry 96, no. 7 (July 2018): 614–20. http://dx.doi.org/10.1139/cjc-2017-0678.

Full text

Abstract:

UV Raman spectra were measured using a novel experimental configuration. This configuration allows many of the difficulties associated with UV excitation and high-power pulsed laser sources to be mitigated. Large sample areas are imaged into the detection system allowing high power excitation sources to be used while simultaneously avoiding sample degradation and multi-photon absorption effects. Such large detection areas allow large numbers of molecular scatters to be probed even with minimal penetration depth. Alignment issues between sample and collection optics are also simplified. Several common solvents were studied using 213 nm light and their spectra reported.

APA, Harvard, Vancouver, ISO, and other styles

20

Derraji, K., C. Favotto, J.-C. Valmalette, S. Villain, J.-R. Gavarri, G. Nolibe, A. Lyoussi, and F. Guinneton. "Role of chemical substitution in the photoluminescence properties of cerium samarium tungstates Ce(2-x)Smx (WO4)3 (0≤x≤0.3)." EPJ Web of Conferences 225 (2020): 01013. http://dx.doi.org/10.1051/epjconf/202022501013.

Full text

Abstract:

In the general framework of the development of materials with tunable photoluminescence, a series of cerium samarium tungstates Ce(2-x)Smx(WO4)3 with x≤0.3 was synthesized by a coprecipitation method followed by thermal treatment at 1000 °C. The polycrystalline compounds were characterized by X-ray diffraction, scanning electron microscopy and photoluminescence experiments. In the present work, the objective would be to determine the role of PL emitting centers in the variations of PL intensities. Firstly, Rietveld analysis showed a decrease of cell parameters and confirmed that a solid solution was obtained. Diffraction profile analyses showed that structural distortions increasing with composition x were observed: they were ascribed to difference in cation sizes of Ce3+ and Sm3+, and to defects generated during crystal growth. The photoluminescence (PL) spectra were obtained under X-Ray (45 kV-35 mA) and UV (364.5 nm) excitations. Two PL emissions of Ce3+ were observed only under UV excitation. Four PL emissions of Sm3+ were observed under UV and X-ray excitations, and their intensities decreased with increasing composition x. Two additional transitions were observed under UV and X-ray excitations: they were attributed to oxygen vacancy defects. In the range 800 to 1000 nm, an increasing IR emission is observed: it was ascribed to emissions due to other oxygen vacancies. The main results are reported in Table 1. The chromaticity diagram (see Figure 1) showed that the colors associated with PL responses vary with Sm composition and excitation energies. This offers the opportunity to develop materials with tunable PL. To better understand this complex behavior, now, we plan to study the solid solution in the composition range x>0.3.

APA, Harvard, Vancouver, ISO, and other styles

21

Kawara, Kimiaki. "H2 Emission from External Galaxies." Symposium - International Astronomical Union 150 (1992): 103–7. http://dx.doi.org/10.1017/s0074180900089786.

Full text

Abstract:

2 μm spectroscopic observations by many authors have revealed significant rotation-vibrational H2 emission is widespread from starburst to bare nucleus galaxies. Near-IR H2 emission lines can arise from various excitation sources: UV radiation by hot stars, shock excitation by supernova remnants or AGN driven winds, and UV/X-ray radiation by an AGN. In this review recent data will be compared with such H2 excitation models.

APA, Harvard, Vancouver, ISO, and other styles

22

Yoshida, Hisashi, Maki Minamoto, Masato Hayashi, Takeshi Hirai, and Shiro Sakuragi. "UV Phosphors for Highly Efficient Excitation by VUV." Journal of the Institute of Image Information and Television Engineers 55, no. 4 (2001): 566–70. http://dx.doi.org/10.3169/itej.55.566.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

DOMEN, Kazunari. "Electronic excitation process of adsorbates by UV lasers." Review of Laser Engineering 18, no. 4 (1990): 203–12. http://dx.doi.org/10.2184/lsj.18.4_203.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Fotiou, Fotios K., and Michael D. Morris. "Photothermal Deflection Densitometer with Pulsed-UV Laser Excitation." Applied Spectroscopy 40, no. 5 (July 1986): 700–704. http://dx.doi.org/10.1366/0003702864508610.

Full text

Abstract:

First application of pulsed photothermal deflection spectroscopy to solid samples is demonstrated. A new densitometer for thin layer chromatography based on this method is described. The technique is suitable for direct measurements in the ultraviolet region. A pulsed excimer laser is used to produce a transient thermal refractive index gradient. The laser delivers pulses of 1–2 mJ at 10–22 pulses/s, at 351 nm. With this system the detection limit for 2,4-dinitroaniline is 750 pg. The signal is linear with amount of analyte for about three orders of magnitude.

APA, Harvard, Vancouver, ISO, and other styles

25

Smirnov, Yu M. "Electron-impact excitation of UV lines of DyI." Physica Scripta 49, no. 6 (June 1, 1994): 689–95. http://dx.doi.org/10.1088/0031-8949/49/6/009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Sivaprakasam, Vasanthi, Alan L. Huston, Cathy Scotto, and Jay D. Eversole. "Multiple UV wavelength excitation and fluorescence of bioaerosols." Optics Express 12, no. 19 (2004): 4457. http://dx.doi.org/10.1364/opex.12.004457.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Carvalho, I. C. S., B. Lesche, and W. Margulis. "Preparation of frequency-doubling fibers under UV excitation." Optics Letters 16, no. 19 (October 1, 1991): 1487. http://dx.doi.org/10.1364/ol.16.001487.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Chandrasekhar, N., O. Schalk, and A. N. Unterreiner. "Femtosecond UV Excitation in Imidazolium-Based Ionic Liquids." Journal of Physical Chemistry B 112, no. 49 (December 11, 2008): 15718–24. http://dx.doi.org/10.1021/jp804861z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Biehl, H., and F. Stuhl. "Vacuum UV absorption and excitation spectra of N2H4." Journal of Photochemistry and Photobiology A: Chemistry 59, no. 2 (July 1991): 135–42. http://dx.doi.org/10.1016/1010-6030(91)87001-c.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Jia, W., D. Jia, T. Rodriguez, D. R. Evans, R. S. Meltzer, and W. M. Yen. "UV excitation and trapping centers in CaTiO3:Pr3+." Journal of Luminescence 119-120 (July 2006): 13–18. http://dx.doi.org/10.1016/j.jlumin.2005.12.067.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Guivan, M. M., A. N. Malinin, A. Brablec, J. Janča, P. Sťahel, and P. Slavíček. "Excitation of phosphors by UV XeI excimer radiation." Czechoslovak Journal of Physics 56, S2 (October 2006): B659—B664. http://dx.doi.org/10.1007/s10582-006-0267-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Luchechko, Andriy P., Igor I. Syvorotka, Yaroslav Zakharko, and I. M. Syvorotka. "Growing Features and Luminescence of Bi³⁺ Ions in Gd₃Ga₅O₁₂ Epitaxial Films." Solid State Phenomena 200 (April 2013): 215–19. http://dx.doi.org/10.4028/www.scientific.net/ssp.200.215.

Full text

Abstract:

Abstract. Excitation and emission spectra under UV and X-ray excitations, as well as the luminescence decay kinetics of Gd3Ga5O12: Bi single crystalline films were studied. The emission spectra observed in the spectral region 350-700 nm at room temperature consist two elementary bands peaked at 446 and 521 nm. The influence of growth conditions on the luminescent properties of Gd3Ga5O12: Bi3+ garnet have been revealed. The integral and relative intensities of the luminescence bands depend on the excitation wavelength. The Bi3+ decay curves of all investigated films show non-single exponential behavior at room temperature.

APA, Harvard, Vancouver, ISO, and other styles

33

Bykov, Sergei, Igor Lednev, Anatoli Ianoul, Aleksandr Mikhonin, Calum Munro, and Sanford A. Asher. "Steady-State and Transient Ultraviolet Resonance Raman Spectrometer for the 193–270 nm Spectral Region." Applied Spectroscopy 59, no. 12 (December 2005): 1541–52. http://dx.doi.org/10.1366/000370205775142511.

Full text

Abstract:

We describe a state-of-the-art tunable ultraviolet (UV) Raman spectrometer for the 193–270 nm spectral region. This instrument allows for steady-state and transient UV Raman measurements. We utilize a 5 kHz Ti-sapphire continuously tunable laser (∼20 ns pulse width) between 193 nm and 240 nm for steady-state measurements. For transient Raman measurements we utilize one Coherent Infinity YAG laser to generate nanosecond infrared (IR) pump laser pulses to generate a temperature jump (T-jump) and a second Coherent Infinity YAG laser that is frequency tripled and Raman shifted into the deep UV (204 nm) for transient UV Raman excitation. Numerous other UV excitation frequencies can be utilized for selective excitation of chromophoric groups for transient Raman measurements. We constructed a subtractive dispersion double monochromator to minimize stray light. We utilize a new charge-coupled device (CCD) camera that responds efficiently to UV light, as opposed to the previous CCD and photodiode detectors, which required intensifiers for detecting UV light. For the T-jump measurements we use a second camera to simultaneously acquire the Raman spectra of the water stretching bands (2500–4000 cm−1) whose band-shape and frequency report the sample temperature.

APA, Harvard, Vancouver, ISO, and other styles

34

He, Da Wei, Yan Ning Shi, Tao Hou, and Dan Zhou. "Luminescence Properties of M₂MgSi₂O₇: Re (M = Ba, Sr, Ca) (Re = Eu²⁺, Ce³⁺, Tb³⁺)." Key Engineering Materials 336-338 (April 2007): 622–24. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.622.

Full text

Abstract:

A series of phosphors of M2MgSi2O7: Eu2+ (M=Ba,Sr,Ca) have been synthesized and studied. The excitation spectra measurement showed that the phosphors had absorption in long UV light, the excitation spectra of the phosphors consisted of two broad bands: one in the range from 280nm to 330 nm and the other from 360nm to 420 nm. The main excitation band centered at around 395nm was belong to 4f→5d transitions of Eu2+. Analysis of the spectra of Ce3+ and Tb3+ co-doped phosphor showed that energy transfer from Ce3+ to Tb3+ in Ba2MgSi2O7 under UV excitation was efficient.

APA, Harvard, Vancouver, ISO, and other styles

35

Yongzhang Jiang, Yongzhang Jiang, Haiping Xia Haiping Xia, Shuo Yang Shuo Yang, Jiazhong Zhang Jiazhong Zhang, Dongsheng Jiang Dongsheng Jiang, Cheng Wang Cheng Wang, Zhigang Feng Zhigang Feng, et al. "Luminescence of Tb3+/Eu3+ codoped LiYF4 single crystals under UV excitation for white-light LEDs." Chinese Optics Letters 13, no. 7 (2015): 071601–71605. http://dx.doi.org/10.3788/col201513.071601.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Fleming, Scott, Andrew Mills, and Tell Tuttle. "Predicting the UV–vis spectra of oxazine dyes." Beilstein Journal of Organic Chemistry 7 (April 15, 2011): 432–41. http://dx.doi.org/10.3762/bjoc.7.56.

Full text

Abstract:

In the current work we have investigated the ability of time-dependent density functional theory (TD-DFT) to predict the absorption spectra of a series of oxazine dyes and the effect of solvent on the accuracy of these predictions. Based on the results of this study, it is clear that for the series of oxazine dyes an accurate prediction of the excitation energy requires the inclusion of solvent. Implicit solvent included via a polarizable continuum approach was found to be sufficient in reproducing the excitation energies accurately in the majority of cases. Moreover, we found that the SMD solvent model, which is dependent on the full electron density of the solute without partitioning into partial charges, gave more reliable results for our systems relative to the conductor-like polarizable continuum model (CPCM), as implemented in Gaussian 09. In all cases the inclusion of solvent reduces the error in the predicted excitation energy to <0.3 eV and in the majority of cases to <0.1 eV.

APA, Harvard, Vancouver, ISO, and other styles

37

Sun, Jia Yue, Xiang Yan Zhang, Ji Cheng Zhu, Yi Ning Sun, and Hai Yan Du. "Luminescence Properties of Novel Red Phosphor NaSrPO₄:Eu³⁺." Advanced Materials Research 502 (April 2012): 128–31. http://dx.doi.org/10.4028/www.scientific.net/amr.502.128.

Full text

Abstract:

A novel red-emitting NaSrPO4:Eu3+ phosphor was prepared by a conventional solid-state reaction. The luminescence properties and temperature dependence of 4:Eu3+ were investigated. The phosphor exhibited red luminescence under the near-UV excitation of 395 nm, corresponding to the 5F0→7L6 transition of Eu3+ ions, which matched well with the excitation wavelength of near-UV LED chips. The electronic transition due to 5D0→7F2 transition of Eu3+ ions is stronger than the magnetic dipole transition due to 5D0→7F1 of Eu3+ ions. Furthermore, Eu3+-doped NaSrPO4 phosphor shows higher thermally stable luminescence comparable tocommercially available Y3Al5O12:Ce3+ phosphor. All the investigated suggested that this newly developed phosphor could find applications in white light devise utilizing InGaN-based excitation in the near-UV chips.

APA, Harvard, Vancouver, ISO, and other styles

38

Das, Rupali, and R. K. Soni. "Rhodium nanocubes and nanotripods for highly sensitive ultraviolet surface-enhanced Raman spectroscopy." Analyst 143, no. 10 (2018): 2310–22. http://dx.doi.org/10.1039/c8an00341f.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Goller, B., and M. Kubbies. "UV lasers for flow cytometric analysis: HeCd versus argon laser excitation." Journal of Histochemistry & Cytochemistry 40, no. 4 (April 1992): 451–56. http://dx.doi.org/10.1177/40.4.1372632.

Full text

Abstract:

Applying flow cytometric single cell analysis, we compared the performance of UV excitation from argon ion and HeCd lasers using various UV-excitable fluorochromes of cell kinetic and cell physiological relevance. The AT-specific DNA fluorochromes DAPI, Hoechst 33258, and Hoechst 33342 showed no significant differences of G1-phase resolution and cell cycle distribution. With the HeCd laser, high-resolution cell kinetic analysis applying the novel BrdU/Hoechst-PI quenching technique showed superior resolution and an almost normalized G2M/G1 channel ratio of the first cell cycle. Indo-1 analysis for detection of intracellular free calcium gave similar results for both excitation sources, although the indo-1 ratio of activated cells was lower for HeCd excitation. Monochlorobimane as an indicator fluorochrome of glutathione content could not be excited sufficiently with the 325-nm line of the HeCd laser and exhibited poor resolution between positive and negative cells. However, the second glutathione-specific fluorochrome o-phtalaldehyde gave even better results with the HeCd laser. Our data indicate that air-cooled HeCd lasers are cheap and reliable UV-excitation sources for most UV-excitable fluorochromes, and might be an alternative to the expensive water-cooled argon and krypton laser.

APA, Harvard, Vancouver, ISO, and other styles

40

Rama Raju, G. Seeta, E. Pavitra, Goli Nagaraju, Xiang-Yu Guan, and Jae Su Yu. "UV-A and UV-B excitation region broadened novel green color-emitting CaGd2ZnO5:Tb3+ nanophosphors." RSC Advances 5, no. 28 (2015): 22217–23. http://dx.doi.org/10.1039/c4ra15376f.

Full text

Abstract:

CaGd₂ZnO₅:Tb³⁺ nanophosphors showed the broadened excitation region as compared to Y₂O₃:Tb³⁺ and Gd₂O₃:Tb³⁺ phosphors, which covered almost the entire UV-B and UV-A regions.

APA, Harvard, Vancouver, ISO, and other styles

41

Engholm, M., L. Norin, and D. Åberg. "Strong UV absorption and visible luminescence in ytterbium-doped aluminosilicate glass under UV excitation." Optics Letters 32, no. 22 (November 14, 2007): 3352. http://dx.doi.org/10.1364/ol.32.003352.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Bhartia, Rohit, Willam F. Hug, Everett C. Salas, Ray D. Reid, Kripa K. Sijapati, Alexandre Tsapin, William Abbey, Kenneth H. Nealson, Arthur L. Lane, and Pamela G. Conrad. "Classification of Organic and Biological Materials with Deep Ultraviolet Excitation." Applied Spectroscopy 62, no. 10 (October 2008): 1070–77. http://dx.doi.org/10.1366/000370208786049123.

Full text

Abstract:

We show that native fluorescence can be used to differentiate classes or groups of organic molecules and biological materials when excitation occurs at specific excitation wavelengths in the deep ultraviolet (UV) region. Native fluorescence excitation–emission maps (EEMs) of pure organic materials, microbiological samples, and environmental background materials were compared using excitation wavelengths between 200–400 nm with emission wavelengths from 270 to 500 nm. These samples included polycyclic aromatic hydrocarbons (PAHs), nitrogen- and sulfur-bearing organic heterocycles, bacterial spores, and bacterial vegetative whole cells (both Gram positive and Gram negative). Each sample was categorized into ten distinct groups based on fluorescence properties. Emission spectra at each of 40 excitation wavelengths were analyzed using principal component analysis (PCA). Optimum excitation wavelengths for differentiating groups were determined using two metrics. We show that deep UV excitation at 235 (±2) nm optimally separates all organic and biological groups within our dataset with >90% confidence. For the specific case of separation of bacterial spores from all other samples in the database, excitation at wavelengths less than 250 nm provides maximum separation with >6σ confidence.

APA, Harvard, Vancouver, ISO, and other styles

43

Geoghegan, Mark, Marta M. Mróz, Chiara Botta, Laurie Parrenin, Cyril Brochon, Eric Cloutet, Eleni Pavlopoulou, Georges Hadziioannou, and Tersilla Virgili. "Optical Gain in Semiconducting Polymer Nano and Mesoparticles." Molecules 26, no. 4 (February 20, 2021): 1138. http://dx.doi.org/10.3390/molecules26041138.

Full text

Abstract:

The presence of excited-states and charge-separated species was identified through UV and visible laser pump and visible/near-infrared probe femtosecond transient absorption spectroscopy in spin coated films of poly[N-9″-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) nanoparticles and mesoparticles. Optical gain in the mesoparticle films is observed after excitation at both 400 and 610 nm. In the mesoparticle film, charge generation after UV excitation appears after around 50 ps, but little is observed after visible pump excitation. In the nanoparticle film, as for a uniform film of the pure polymer, charge formation was efficiently induced by UV excitation pump, while excitation of the low energetic absorption states (at 610 nm) induces in the nanoparticle film a large optical gain region reducing the charge formation efficiency. It is proposed that the different intermolecular interactions and molecular order within the nanoparticles and mesoparticles are responsible for their markedly different photophysical behavior. These results therefore demonstrate the possibility of a hitherto unexplored route to stimulated emission in a conjugated polymer that has relatively undemanding film preparation requirements.

APA, Harvard, Vancouver, ISO, and other styles

44

Das, Hrishikesh, Swapna Sunkari, Oener Akdik, Andrei Konstantinov, Krister Gumaelius, Jan Olov Svedberg, and Fredrik Allerstam. "Evaluation of the Effect of Ultraviolet Light Excitation during Characterization of Silicon Carbide Epitaxial Layers." Materials Science Forum 924 (June 2018): 261–64. http://dx.doi.org/10.4028/www.scientific.net/msf.924.261.

Full text

Abstract:

The scanning of Silicon Carbide (SiC) epitaxy wafers for defects by ultraviolet (UV) laser or lamps is widely prevalent. In this work, we document the effects of UV light excitation on the SiC epitaxy material. An increase in background photoluminescence (PL) is observed after repeated scans. The effect of this increase on defect detection is shown. Optimal surface treatments to recover the material back to the original state are demonstrated. Further, some surface treatments are proposed which reduce the effect of the UV light excitation and prevent to a large extent the rise in background PL.

APA, Harvard, Vancouver, ISO, and other styles

45

Lansley, S. P., R. D. McKeag, M. D. Whitfield, N. Rizvi, and R. B. Jackman. "Diamond photodetector response to deep UV excimer laser excitation." Diamond and Related Materials 12, no. 3-7 (March 2003): 677–81. http://dx.doi.org/10.1016/s0925-9635(03)00064-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Gao, Hui, and Yuhua Wang. "Photoluminescence of Eu3+ activated YAlO3 under UV–VUV excitation." Materials Research Bulletin 42, no. 5 (May 2007): 921–27. http://dx.doi.org/10.1016/j.materresbull.2006.08.010.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Ewart, M., M. Zgonik, and P. Günter. "Nanosecond optical response to pulsed uv excitation in KNbO3." Optics Communications 141, no. 1-2 (August 1997): 99–106. http://dx.doi.org/10.1016/s0030-4018(97)00175-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Asher, Sanford A., and James L. Murtaugh. "UV Raman Excitation Profiles of Imidazole, Imidazolium, and Water." Applied Spectroscopy 42, no. 1 (January 1988): 83–90. http://dx.doi.org/10.1366/0003702884428653.

Full text

Abstract:

Preresonance absolute differential Raman cross sections have been measured between 217 and 600 nm for the symmetric ring mode vibrations of imidazole and imidazolium and for the 1645-cm−1 bending vibration of water. For imidazole and imidazolium the Raman intensities observed with visible wavelength excitation derive mainly from states in the far-UV. The two 190–210 nm π → π* transitions in these species dominate the Raman intensities only for excitation below 300 nm. Both π → π* transitions appear to contribute equally to preresonance enhancement. The data project that selective imidazole ring enhancement from histidine residues in proteins will require excitation below 210 nm. The intensities of the 1645-cm−1 bending vibration of water derive from states in the far-UV. The Raman cross section of this vibration increases only slightly faster than the scattered frequency to the fourth power. This Raman band can now be used as an internal intensity standard for aqueous Raman studies. Preresonance Raman enhancement dominated by transitions which occur at extraordinarily high energies have now been observed for water, acetonitrile, acetone, sulfate, and perchlorate. This behavior may result because molecular valence transitions in the vacuum UV spectral region of condensed phase samples are strongly mixed with ionizing, charge transfer, and Rydberg transitions and have no separate and discrete existence.

APA, Harvard, Vancouver, ISO, and other styles

49

Játékos, B., E. Lőrincz, A. Barócsi, and G. Erdei. "Gamma-photon equivalent UV excitation of LYSO:Ce scintillator material." Journal of Instrumentation 10, no. 04 (April 21, 2015): P04007. http://dx.doi.org/10.1088/1748-0221/10/04/p04007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Nielsen, Jakob Brun, Jan Thøgersen, Svend Knak Jensen, Steen Brøndsted Nielsen, and Søren Rud Keiding. "Vibrational dynamics of deoxyguanosine 5′-monophosphate following UV excitation." Physical Chemistry Chemical Physics 13, no. 30 (2011): 13821. http://dx.doi.org/10.1039/c1cp20918c.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Excitation uv'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles