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991.
R. Centore P. Riccio S. Fusco A. Carella A. Quatela S. Schutzmann F. Stella F. De Matteis 《Journal of polymer science. Part A, Polymer chemistry》2007,45(13):2719-2725
We have prepared new polyesters containing quadratic, nonlinear optical (NLO) active chromophores covalently incorporated into the main chain. In these polymers, the sequence of the chromophore units along the main chain is rigorously head to tail. All the polyesters are processable, both in the melt and in solution. For one polyester, a full second‐order NLO characterization has been performed. An out‐of‐resonance d33 coefficient of 21 pm/V at 1368 nm has been measured. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2719–2725, 2007 相似文献
992.
This paper deals with the small-angle neutron scattering (SANS) investigation on solution-quenched PH13-8 Mo stainless steel.
From the nature of the variation of the functionality of the profiles for varying specimen thickness and also from the transmission
electron microscopy (TEM), it has been established that the small-angle scattering signal predominantly originates from the
block-like metallic carbide precipitates in the specimen. The contribution due to double Bragg reflection is not significant
in the present case. The single scattering profile has been extracted from the experimental profiles corresponding to different
values of specimen thickness. In order to avoid complexity and non-uniqueness of the multi-parameter minimization for randomly
oriented polydisperse block-like precipitate model, the data have been analyzed assuming randomly oriented polydisperse cylindrical
particle model with a locked aspect ratio. 相似文献
993.
The triple differential cross-section for K-shell ionization of silver and copper atoms by relativistic electrons have been
computed in the coplanar symmetric geometry with the inclusion of exchange effects following the multiple scattering theory
of Das and Seal [1] multiplied by suitable spinors. Present computed results are marginally improved in some cases from the
previous computed results [2]. Present results are compared with measured values [3] and with previous computation results
[2]. Some other theoretical computational results are also presented here for comparison.
相似文献
994.
Daria E. Lonsdale Geoffrey Johnston‐Hall Amanda Fawcett Craig A. Bell Carl N. Urbani Michael R. Whittaker Michael J. Monteiro 《Journal of polymer science. Part A, Polymer chemistry》2007,45(16):3620-3625
In this work, we propose that retardation in vinyl acetate polymerization rate in the presence of toluene is due to degradative chain transfer. The transfer constant to toluene (Ctrs) determined using the Mayo method is equal to 3.8 × 10?3, which is remarkably similar to the value calculated from the rate data, assuming degradative chain transfer (2.7 × 10?3). Simulations, including chain‐length‐dependent termination, were carried out to compare our degradative chain transfer model with experimental results. The conversion–time profiles showed excellent agreement between experiment and simulation. Good agreement was found for the Mn data as a function of conversion. The experimental and simulation data strongly support the postulate that degradative chain transfer is the dominant kinetic mechanism. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3620–3625, 2007 相似文献
995.
T. Wagner J. Gutwirth P. Nemec M. Frumar T. Wagner M. Vlcek V. Perina A. Mackova V. Hnatovitz 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1561-1562
The pulsed laser deposition technique has been applied to prepare amorphous ternary AgSbS films. The films were prepared from AgSbS2 bulk glass using a KrF excimer laser. The composition of prepared films according to the results of the energy dispersive X-ray analysis and the Rutherford backscattering was close to bulk one. Optical transmission and spectral dependence of the refractive index proved the good optical quality of the films. The Ar+ ion laser dot exposures of the films show a potential applicability of the films as a new type of optical recording material. PACS 78.66.Jg; 81.15.Fg; 81.40.Wx 相似文献
996.
O.M. Hussain A.S. Swapnasmitha J. John R. Pinto 《Applied Physics A: Materials Science & Processing》2005,81(6):1291-1297
The structure and surface morphology of WO3 thin films deposited by a laser-ablation technique have been found to be strongly dependent on the deposition conditions and the nature of the substrate. By precisely controlling the substrate temperature and the oxygen partial pressure, amorphous, polycrystalline, nano-crystalline and iso-epitaxial WO3 thin films were successfully grown. The structure and surface morphological features of the films from X-ray diffraction and atomic force microscopy data are described in relation to the deposition conditions. PACS 81.15.Fg; 68.55.-a; 68.37.Ps 相似文献
997.
M. Tscherneck J. Kleinert C. Haimberger M. E. Holmes N. P. Bigelow 《Applied physics. B, Lasers and optics》2005,80(6):639-643
Ultracold molecules have been produced by photoassociation of Cs atoms trapped in a mirror magneto-optical trap. The molecules
were detected by resonantly enhanced multi-photon ionization followed by time-of-flight mass spectroscopy. The time-of-flight
ofatomic and molecular ions was investigated in the presence of a dc bias voltageapplied to the conducting mirror. This technique
provides a new tool for determining the distance between the cold molecules and the mirror surface.
This revised version was published online in August 2005 with a corrected cover date. 相似文献
998.
D. Ohlberg J.J. Blackstock R. Ragan S. Kim R. Stanley Williams 《Applied Physics A: Materials Science & Processing》2005,80(6):1327-1334
A recently demonstrated [1] in-vacuo template-stripping process is applied to the study of platinum films stripped from ultra-flat silicon-oxide surfaces. Template-stripped (TS) Pt surfaces, prepared with a range of post-deposition annealing times prior to being stripped from the templating surface in an ultra-high vacuum (UHV) environment, are examined by UHV scanning tunneling microscopy (STM). These studies reveal that without post-deposition annealing, TS Pt surfaces are largely made up of poorly-ordered, granular nanostructures undesirable for many applications. The post-deposition annealing treatments explored in the study result in the emergence and continuous growth of large smooth crystallites. Issues with crystallite orientation relative to the TS surface and artefacts arising as a result of the epoxy used in the template-stripping process are presented and discussed in relation to optimizing the template-stripping procedure for specific applications such as self-assembled monolayer (SAM) formation for molecular electronics. PACS 68.37.Ef; 68.47.De; 68.55.Jk; 81.05.Bx; 81.15.Ef 相似文献
999.
A. Di Maio A. Rocco P. Ferraro M. De Rosa P. De Natale S. De Nicola A. Finizio G. Pierattini G. Coppola M. Iodice V. Striano 《Optics and Lasers in Engineering》2007,45(3):385
In view of the growing interest for non-destructive tests of materials, geodynamical monitoring and in general remote sensing, there is a great effort to bring practical optical sensors from research labs to industrial and environmental applications. In this paper, we employ digital holographic technique as an efficient tool for evaluating the strain measurement capability of fiber Bragg gratings (FBG). A cantilever beam has been employed as a test structure under loading test. The strain measurements results obtained by fiber-based sensors have been compared to those obtained by using full-field digital holographic technique and point-wise strain gauge sensors glued on the same cantilever beam. A simple theoretical model is also presented to interpret and compare the experimental results coming from different techniques. 相似文献
1000.
Humberto Bustos Rodriguez Dagoberto Oyola Lozano Yebrayl A. Rojas Martínez Germán A. Pérez Alcázar Stefan Flege Adam G. Balogh Louis J. Cabri Michael Tubrett 《Hyperfine Interactions》2007,175(1-3):195-206
X-ray diffraction (XRD), Mössbauer spectrometry (MS), secondary ions mass spectroscopy (SIMS) and laser-ablation microprobe–inductively coupled plasma–mass spectrometry (LAM–ICP–MS) were used to study mineral samples of Colombian auriferous ores collected from the “El Diamante” mine, located in the municipality of Guachavez-Nariño, in Colombia. The samples were prepared as polished thin sections and polished sections. From XRD data, quartz, sphalerite and pyrite were detected and their respective cell parameters were estimated. From MS analyses, pyrite, arsenopyrite and chalcopyrite were identified; their respective hyperfine parameters and respective texture were deduced. Multiple regions of approximately 200 × 200 μm in each sample were analyzed with SIMS; the occurrence of “invisible gold” associated mainly with pyrite and secondarily with arsenopyrite could thus be assigned. It was also found that pyrite is of the arsenious type. Spots from 30 to 40 μm in diameter were analyzed with LAM–ICP–MS for pyrite, arsenopyrite and sphalerite; Au is “homogeneously” distributed inside the structure of the arsenious pyrite and the arsenopyrite (not as inclusions); the chemical composition indicates similarities of this “invisible gold”, forming a solid solution with arsenious pyrite and arsenopyrite. One hundred nineteen and 62 ppm of ‘invisible gold’ was quantified in 21 spots analyzed on pyrite and in 14 spots on arsenopyrite, respectively. 相似文献