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21.
Metal/superconductor/semiconductor (Ag/Hg-1212/CdSe) hetero-nanostructures have been fabricated using pulse-electrodeposition
technique and are characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM) and scanning electron microscopy
(SEM) studies. The junction capacitance of Ag/Hg-1212, Hg-1212/CdSe and Ag/Hg-1212/CdSe heterojunctions is measured in dark
and under laser irradiation at room temperature. The nature of the junction formed and built-in-junction potentials were determined.
The increase in carrier concentration across the junction due to photo-irradiation has been observed. 相似文献
22.
23.
One of the innovative technological directions for the high-temperature superconductors has been persued by fabricating the
heteroepitaxial multilayer structures such as superconductor-semiconductor heterostructures. In the present investigation,
metal/superconductor/semiconductor (Ag/Tl-2223/CdSe) hetero-nanostructures have successfully been fabricated using dc electrodeposition
technique and were characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM) and scanning electron microscopy
(SEM) studies. The measurement of junction capacitance as a function of biasing voltage was used for the estimation of junction
built-in-potential (V
D) and to study the charge distribution in a heterojunction. The Mott-Schottky plots were measured for each junction in dark
and under the photo-irradiation. The effect of laser irradiation on C-V characteristics of hetero-nanostructure has been studied. 相似文献
24.
J. Leonowich S. Pandian I. L. Preiss 《Journal of Radioanalytical and Nuclear Chemistry》1977,40(1-2):175-187
Problems involved in developing radioisotope sources and the characteristics of potentially useful radioisotopes for X-ray
fluorescence analysis are presented. Some of the isotopes, which are not in use but look very promising, are indicated. 相似文献
25.
26.
H. Preiss 《无机化学与普通化学杂志》1972,389(3):293-301
The 70 eV mass spectra of some niobium and antimony alkoxy chlorides are presented and fragmentation processes are discussed. Among the rearrangement reactions observed, several reactions were found providing six-coordinated niobium ions. The compounds are built up by bioctahedra; dimeric ions in addition to monomeric ones are present in the vapour state. The compounds Nb2Cl(OC2H5)9 and Nb2Cl3(OC2H5)7 have been prepared. The association behaviour of compounds of the type MXnYs–n is discussed on the basis of the results of X-ray analysis and mass spectrometry. 相似文献
27.
28.
29.
Even-electron ions: a systematic study of the neutral species lost in the dissociation of quasi-molecular ions 总被引:1,自引:0,他引:1
Levsen K Schiebel HM Terlouw JK Jobst KJ Elend M Preiss A Thiele H Ingendoh A 《Journal of mass spectrometry : JMS》2007,42(8):1024-1044
The collision-induced dissociations of the even-electron [M + H](+) and/or [M - H](-) ions of 121 model compounds (mainly small aromatic compounds with one to three functional groups) ionized by electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI) have been studied using an ion trap instrument, and the results are compared with the literature data. While some functional groups (such as COOH, COOCH(3), SO(3)H in the negative ion mode, or NO(2) in both the positive and negative ion modes) generally promote the loss of neutrals that are characteristic as well as specific, other functional groups (such as COOH in the positive ion mode) give rise to the loss of neutrals that are characteristic, but not specific. Finally, functional groups such as OH and NH(2) in aromatic compounds do not lead to the loss of a neutral that reflects the presence of these substituents. In general, the dissociation of [M + H](+) and [M - H](-) ions generated from aliphatic compounds or compounds containing an aliphatic moiety obeys the even-electron rule (loss of a molecule), but deviations from this rule (loss of a radical) are sometimes observed for aromatic compounds, in particular for nitroaromatic compounds. Thermochemical data and ab initio calculations at the CBS-QB3 level of theory provide an explanation for these exceptions. When comparing the dissociation behaviour of the even-electron [M + H](+) and/or [M - H](-) ions (generated by ESI or APCI) with that of the corresponding odd-electron [M](+) ions (generated by electron ionization, EI), three cases may be distinguished: (1) the dissociation of the two ionic species differs completely; (2) the dissociation involves the loss of a common neutral, yielding product ions differing in mass by one Da, or (3) the dissociations lead to a common product ion. 相似文献
30.
S. Bates W. B. Johnson J. Lindenstrauss D. Preiss G. Schechtman 《Geometric And Functional Analysis》1999,9(6):1092-1127
New concepts related to approximating a Lipschitz function between Banach spaces by affine functions are introduced. Results
which clarify when such approximations are possible are proved and in some cases a complete characterization of the spaces
X, Y for which any Lipschitz function from X to Y can be so approximated is obtained. This is applied to the study of Lipschitz and uniform quotient mappings between Banach
spaces. It is proved, in particular, that any Banach space which is a uniform quotient of L
p
, 1 < p < , is already isomorphic to a linear quotient of L
p
.
Submitted: June 1998, revised: December 1998. 相似文献