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91.
92.
R. Eichele W. Kern R. P. Huebener 《Applied Physics A: Materials Science & Processing》1981,25(2):95-103
We have studied the influence of oxygen on the superconducting properties of thin films of lead, indium and tin deposited
on glass or sapphire substrates. In addition, the morphological microstructure was investigated by scanning electron microscopy.
The film thickness was 1.0 μm, and the partial pressure of O2 during the film deposition was raised up to 1×10−4 Torr. In all three materials the development of a granular structure and a strong increase in the residual electric resistivity
was observed due to the O2-treatment. Whereas in the Pb films no change of the critical temperature was found, the In films deposited on glass substrates
showed a slight increase ofT
c due to the oxygen. The strongest increase ofT
c (up to 8%) was observed in the O2-treated Sn films. These results are discussed in terms of the McMillan theory. From our measurements of the critical current
densityj
c we conclude that edge pinning is dominant in the undoped films. All three materials showed a strong increase ofj
c due to the O2-treatment which must be interpreted in terms of bulk pinning. 相似文献
93.
The electronic and vibrational density of states of a semiconducting carbon nanotube in a crossed junction was investigated by elastic and inelastic scanning tunneling spectroscopy. The strong radial compression of the nanotube at the junction induces local metallization spatially confined to a few nanometers. The local electronic modifications are correlated with the observed changes in the radial breathing and G band phonon modes, which react very sensitively to local mechanical deformation. In addition, the experiments reveal the crucial contribution of the image charges to the contact potential at nanotube-metal interfaces. 相似文献
94.
Sensitivity-enhanced IPAP-SOFAST-HMQC for fast-pulsing 2D NMR with reduced radiofrequency load 总被引:3,自引:1,他引:2
Kern T Schanda P Brutscher B 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2008,190(2):333-338
The SOFAST-HMQC experiment [P. Schanda, B. Brutscher, Very fast two-dimensional NMR spectroscopy for real-time investigation of dynamic events in proteins on the time scale of seconds, J. Am. Chem. Soc. 127 (2005) 8014-8015] allows recording two-dimensional correlation spectra of macromolecules such as proteins in only a few seconds acquisition time. To achieve the highest possible sensitivity, SOFAST-HMQC experiments are preferably performed on high-field NMR spectrometers equipped with cryogenically cooled probes. The duty cycle of over 80% in fast-pulsing SOFAST-HMQC experiments, however, may cause problems when using a cryogenic probe. Here we introduce SE-IPAP-SOFAST-HMQC, a new pulse sequence that provides comparable sensitivity to standard SOFAST-HMQC, while avoiding heteronuclear decoupling during (1)H detection, and thus significantly reducing the radiofrequency load of the probe during the experiment. The experiment is also attractive for fast and sensitive measurement of heteronuclear one-bond spin coupling constants. 相似文献
95.
Dr. Jakob-Jonathan Maudrich Max Widemann Fatima Diab Ralf H. Kern Dr. Peter Sirsch Dr. Christian P. Sindlinger Dr. Hartmut Schubert Prof. Dr. Lars Wesemann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(70):16081-16087
Organodihydridoelement anions of germanium and tin were reacted with metallocene dichlorides of Group 4 metals Ti, Zr and Hf. The germate anion [Ar*GeH2]− reacts with hafnocene dichloride under formation of the substitution product [Cp2Hf(GeH2Ar*)2]. Reaction of the organodihydridostannate with metallocene dichlorides affords the reduction products [Cp2M(SnHAr*)2] (M=Ti, Zr, Hf). Abstraction of a hydride substituent from the titanium bis(hydridoorganostannylene) complex results in formation of cation [Cp2M(SnAr*)(SnHAr*)]+ exhibiting a short Ti–Sn interaction. (Ar*=2,6-Trip2C6H3, Trip=2,4,6-triisopropylphenyl). 相似文献
96.
The Structure of the Cobalt Oxide/Au Catalyst Interface in Electrochemical Water Splitting 下载免费PDF全文
97.
L. Vuaflart E. Truninger A. Stutzer G. Hager J. Kern H. Kappen Ulpiani E. Hene A. van Haaren H. Immendorff und Baessler 《Fresenius' Journal of Analytical Chemistry》1919,58(2):87-96
Ohne Zusammenfassung 相似文献
98.
99.
Radice S Kern P Dietsch H Mischler S Michler J 《Journal of colloid and interface science》2008,318(2):264-270
Functionalization of colloidal particles based on the use of polyelectrolytes and heterocoagulation was combined with electrophoretic deposition (EPD), with the aim of depositing titania-polystyrene (TiO(2)-PS) composite particles on Ti6Al4V substrates. The composite particles were obtained by heterocoagulation of TiO(2) nanoparticles on the surface of monosized polystyrene beads of 4.6 microm in diameter. Two alternative methods were developed for the preparation of the TiO(2)-PS suspensions in organic fluids for cathodic electrodeposition. The first method was carried out in alkaline aqueous medium with the use of polyelectrolytes and intermediate control measurements of zeta potential, conductivity, and pH; the second one was carried out directly in the organic solvent used for EPD, typically isopropanol. Examples of deposits obtained by EPD in both suspensions and a comparative analysis between the two methods are presented. 相似文献
100.
Proch S Herrmannsdörfer J Kempe R Kern C Jess A Seyfarth L Senker J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(27):8204-8212
The gas-phase loading of [Zn(4)O(btb)(2)](8) (MOF-177; H(3)btb=1,3,5-benzenetribenzoic acid) with the volatile platinum precursor [Me(3)PtCp'] (Cp'=methylcyclopentadienyl) was confirmed by solid state (13)C magic angle spinning (MAS)-NMR spectroscopy. Subsequent reduction of the inclusion compound [Me(3)PtCp'](4)@MOF-177 by hydrogen at 100 bar and 100 degrees C for 24 h was carried out and gave rise to the formation of platinum nanoparticles in a size regime of 2-5 nm embedded in the unchanged MOF-177 host lattice as confirmed by transmission electron microscopy (TEM) micrographs and powder X-ray diffraction (PXRD). The room-temperature hydrogen adsorption of Pt@MOF-177 has been followed in a gravimetric fashion (magnetic suspension balance) and shows almost 2.5 wt % in the first cycle, but is decreased down to 0.5 wt % in consecutive cycles. The catalytic activity of Pt@MOF-177 towards the solvent- and base-free room temperature oxidation of alcohols in air has been tested and shows Pt@MOF-177 to be an efficient catalyst in the oxidation of alcohols. 相似文献