Bing-Ming Cheng

  • Citations Per Year
Learn More
Three series of new ultraviolet-emitting Ca(9)Y(PO(4))(7):Ln(3+) (Ln = Ce, Gd, Pr) phosphors were synthesized, and their luminescence was investigated. Under vacuum ultraviolet excitation Ca(9)Y(PO(4))(7):Ce(3+) phosphors emit UVA light with one broad emission centered at 346 nm, on account of the 5d(1) → 4f(1) transition of Ce(3+) ions; the optimal doping(More)
Samples of pure methane and of methane dispersed in solid neon at 3 K subjected to irradiation at wavelengths less than 165 nm with light from a synchrotron yielded varied products that were identified through their infrared absorption spectra, including CH3, C2H2, C2H3, C2H4, C2H6, C4H2, C4H4, C5H2, C8H2, CnH with n = 1-5, and carbon chains Cn with n =(More)
At the vacuum-ultraviolet (VUV) beam line of a synchrotron, an end station for photoluminescence (PL) coupled to a system to detect absorption is used to investigate the luminescence and absorption of materials. We analyzed a CVD diamond window in wavelength range 160 250 nm at 300 and 14 K. The PL excited with VUV light enabled an identification of(More)
Cross sections for photoabsorption of NH3, NH2D, NHD2, and ND3 in the spectral region 140Y220 nm were determined at 298 K using synchrotron radiation. Absorption spectra of NH2D and NHD2 were deduced from spectra of mixtures of NH3 and ND3, of which the equilibrium concentrations for all four isotopologues obey statistical distributions. Cross sections of(More)
The photodissociation of gaseous molecular nitrogen has been investigated intensively, but the corresponding knowledge in a solid phase is lacking. Irradiation of pure solid nitrogen at 3 K with vacuum-ultraviolet light from a synchrotron produced infrared absorption lines of product l-N3 at 1657.8 and 1652.6 cm(-1). The threshold wavelength to generate(More)
The photoionization efficiency ~PIE! spectrum of HSO was measured in the spectral range ~107– 130! nm by means of a discharge flow and a photoionization mass spectrometer coupled to a synchrotron as the radiation source. HSO radicals were generated by reacting O atoms with various organothiol compounds, C2H5SH, 2-C3H7SH, or HSC2H4SH, in the flow tube. The(More)
Various diamonds were analyzed with photoluminescence (PL) spectra excited with synchrotron radiation in the wavelength range 160-250 nm. The emission of type IaAB diamond begins near 300 nm and extends to 700 nm; two broad lines with maximums about 419 and 469 nm correspond to energies 2.96 and 2.64 eV, respectively. The spectral features observed in the(More)
The room temperature absorption spectra of water and its isotopomers D2O and HOD have been determined in absolute cross section units in the 125 to 145 nm wavelength region using synchrotron radiation. The experimental results for these B band spectra are compared with results from quantum mechanical calculations using accurate diabatic ab initio(More)
Photoluminescence (PL) spectra of natural diamond powders of type IaAB at 300 and 13 K were excited with synchrotron radiation in the wavelength range of 150-260 nm. The spectral features observed in the excitation spectra at 13 K show four vibrational progressions related to nitrogen defects in diamond: A, B, B', and N3. Progression A has a spacing of 1258(More)