排序方式: 共有127条查询结果,搜索用时 93 毫秒
21.
Surface-modification of indium tin oxide nanoparticles with titanium dioxide by a nonaqueous process and its photocatalytic properties 总被引:1,自引:0,他引:1
Indium tin oxide nanoparticles prepared by co-precipitation were re-dispersed in benzyl alcohol and modified successfully with titanium dioxide using titanium tetrachloride as precursor. The morphologies and the re-dispersing processes of both the initial and modified indium tin oxide nanoparticles were investigated, respectively. The photocatalytic properties of the modified nanoparticles were compared with commercial P25 photocatalyst. It was found that (i) the average diameter of the initial indium tin oxide nanoparticles was 10.7 nm and that of the surface-modified nanoparticles was 14.5 nm; (ii) the optimal ultrasonication time was 10.0 min and 8.0 min for the initial and surface-modified ITO nanoparticles, respectively; (iii) the modified particles possessed a higher photocatalytic activity than commercial P25 photocatalyst in the photodegradation of rhodamine B in aqueous medium at pH 5.00; (iv) the pH of the medium markedly influences the photodegradation efficiency. 相似文献
22.
Harald Etschmaier Peter Pacher Alexandra Lex Gregor Trimmel Christian Slugovc Egbert Zojer 《Applied Physics A: Materials Science & Processing》2009,95(1):43-48
For the design and manufacture of complex integrated circuits, control over the threshold voltage of the transistors is essential.
In the present contribution, we present a non-invasive method to tune the threshold voltage of organic thin-film transistors
after device assembly over a wide range without any significant degradation of the device characteristics. This is realized
by incorporating a thin, chemically reactive siloxane layer bonded to the gate oxide. This results in threshold voltages of
around 70 V in the as-prepared devices. By exposing a transistor modified in this way to ammonia at different concentrations,
the threshold voltage can be tuned in steps of only a few volts. This treatment affects only the charge density at the semiconductor–dielectric
interface, leaving the overall shape of the transistor characteristics and the charge-carrier mobility largely unaltered. 相似文献
23.
C. Kloc K. J. Tan M. L. Toh K. K. Zhang Y. P. Xu 《Applied Physics A: Materials Science & Processing》2009,95(1):219-224
Liquid chromatography connected with mass spectroscopy reveals that the oxidized form of rubrene is the major impurity in
commercial powder of rubrene as well as in rubrene single crystals. One form of rubrene impurity can be transformed into the
other. In solution, rubrene undergoes photo-oxidation completely until the red color of the rubrene solution disappears. Single
crystals, due to compact packing of molecules and the required molecular shape change during oxidation, oxidize only on the
surface. 相似文献
24.
A possibility to apply the advantages of chlorinated carbon precursors, which had been previously used in low‐temperature epitaxial growth of 4H‐SiC, to achieve very high growth rates at higher growth temperatures was investigated. Silicon tetrachloride was used as the silicon precursor to suppress gas‐phase homogeneous nucleation. The temperature increase from 1300 °C (which is the temperature of the previously reported low‐temperature halo‐carbon epitaxial growth) to 1600 °C enabled an increase of the precursor flow rates and consequently of the growth rate from 5 to more than 100 μm/h without morphology degradation. High quality of the epilayers was confirmed by low‐temperature photoluminescence spectroscopy and time‐resolved luminescence. No evidences of homogeneous nucleation were detected, however, liquid Si droplet formation on the epilayer surface seems to remain a bottleneck at very high growth rate. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
25.
Cross sections for electron impact excitation of lithium from the ground state 1s^22s to the excited states 1s2s^2, 1s2p^2, 1s2snp (n = 2-5), 1s2sns (n = 3 5), 1s2pns (n = 3-5), and 1s2pnp (n = 3-5) are calculated by using a full relativistic distorted wave method. The latest experimental electron energy loss spectra for inner-shell electron excitations of lithium at a given incident electron energy of 2500 eV [Chin. Phys. Lett. 25 (2008)3649] have been reproduced by the present theoretical investigation excellently. At the same time, the structures of electron energy loss spectra of lithium at low incident electron energy are also predicted theoretically, it is found that the electron energy loss spectra in the energy region of 55-57eV show two-peak structures. 相似文献
26.
M. Matuchova K. Zdansky J. Zavadil A. Danilewsky F. Riesz M.A.S. Hassan D. Alexiew R. Kral 《Journal of Crystal Growth》2009,311(14):3557-3562
Lead iodide (PbI2) shows excellent electronic properties for detection of ionizing radiation. We report the introduction of rare-earth elements and other elements as admixtures during synthesis to study their influence on the quality of single crystals. Synthesized material as well as single crystals have been characterized by measurements of electrical resistivity and low-temperature photo luminescence and index of refraction. The structural quality with respect to polytypes was analysed by electron back scatter diffraction. Makyoh topography was applied for surface studies. 相似文献
27.
M.N. Mineva M. Hellström M. Bernas J. Gerl H. Grawe M. Pfützner P.H. Regan M. Rejmund D. Rudolph F. Becker C.R. Bingham T. Enqvist B. Fogelberg H. Gausemel H. Geissel J. Genevey M. Górska R. Grzywacz K. Hauschild Z. Janas I. Kojouharov Y. Kopatch A. Korgul W. Korten J. Kurcewicz M. Lewitowicz R. Lucas H. Mach S. Mandal P. Mayet C. Mazzocchi J.A. Pinston Zs. Podolyàk H. Schaffner Ch. Schlegel K. Schmidt K. Sümmerer H.J. Wollersheim 《The European Physical Journal A - Hadrons and Nuclei》2001,11(1):9-13
Rapidity correlations in 800 GeV proton interactions with emulsion nuclei are investigated for different targets and multiplicity
regions. To study the energy dependence, the results have been compared with proton interactions at 200 GeV and 400 GeV. A
common feature of all the interactions is the existence of strong, short-range correlations. However, no dependence of cluster
parameters on primary energy or target mass is found. A marginal increase of correlation strength with multiplicity is observed.
Received: 30 March 2001 / Accepted: 18 September 2001 相似文献
28.
A nonlinear iterative learning algorithm is proposed to make a voltage waveform in the secondary coil sinusoidal in this paper. The algorithm employs a globally convergent Jacobian-free quasi-Newton type solver that has a BFGS-like structure. This method functions well, and it is demonstrated using typical soft magnetic materials. 相似文献
29.
An efficient quantum secure direct communication protocol with one-sender versus N-receiver is proposed. The secret bits can be encoded in the N + 1-particle GHZ states and can be decoded by the N receivers with a classical information of the sender plus their own measurement outcomes. Any attacks can be detected by comparing measurement results on the detecting states. 相似文献
30.
Photoluminescence of undoped and Cr3+-doped β-Ga2O3 was investigated. The transparent, undoped β-Ga2O3 film was successfully prepared by thermal conversion from GaOOH. The film exhibited predominant green luminescence in response to ultraviolet light excitation at 250 nm. This luminescence behavior, which was proposed to result from the oxygen defect centers, was used in examining excitation and emission mechanisms for Cr3+ ions doped in β-Ga2O3. It was found that red luminescence of Cr3+ surpasses green luminescence of the host lattice, as evidenced by the dependence of the spectral structure on the Cr3+ concentration. The excitation of Cr3+ was then suggested to be caused by the energy transfer from Ga3+O6 octahedra present in the monoclinic β-Ga2O3 lattice. 相似文献