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61.
K. Sauer 《等离子体物理论文集》1967,7(4):303-320
The nonlinear interaction of waves in anisotropic plasmas is considered. Solving the hydrodynamics equations with a n-th order perturbation procedure, an equation for the nonlinear electric field is derived. The n-th order current produced by interaction of waves with lower order is represented by means of a nonlinear tensor of conductivity, which is calculated for n = 2. It is shown, that a miced plasma wave with combination frequencies is excited as the result of interaction of two transverse (ordinary) waves propagating perpendicular to the magnetic field. 相似文献
62.
Preininger C Sauer U Dayteg J Pichler R 《Bioelectrochemistry (Amsterdam, Netherlands)》2005,67(2):155-162
Signal enhancement of oligonucleotide and protein arrays on ARChip Epoxy was achieved by optimizing chip processing parameters. The parameters investigated were fabrication, blocking and guide dot concentration, probe concentration and modification, print buffer, humidity during arraying, slide agitation, spot volume and spotter compatibility. The optimum oligonucleotide concentration was 20 microM, while the optimum protein concentration was 0.05 mg/ml. Amino-modified oligonucleotides were best able to be bound to the resin's epoxy groups at pH 8, whereas thiol-modified oligonucleotides displayed an optimum coupling value of pH 7. So as to avoid background (BG) contamination of probes around bright guide dots, the concentration of fluorescent guide dots was set to 1 muM. The most suitable print buffers for oligonucleotide arrays using both piezo- and contact-printing systems proved to be 3 x SSC/1.5 M betaine and commercial ArrayLink. When 0.01% monochlortriazinyl-beta-cyclodextrin sodium salt (MCT) was added, the hybridization signal doubled in strength as compared to plain buffer. The optimum print buffer for proteins was 0.1 N phosphate buffer, pH 8/10% glycerine. The optimum humidity for arraying oligonucleotides was 60% and for proteins 40%. Initially agitating slides for 15 min was found just as effective as agitating slides over the total hybridization period (2.5 h), and this resulted in a three times stronger signal. 相似文献
63.
We describe an alkali-metal magnetometer for detection of weak magnetic fields in the radio-frequency (rf) range. High sensitivity is achieved by tuning the Zeeman resonance of alkali atoms to the rf frequency and partially suppressing spin-exchange collisions in the alkali-metal vapor. We demonstrate magnetic field sensitivity of 2 fT/Hz(1/2) at a frequency of 99 kHz with a resonance width of 400 Hz. We also derive a simple analytic expression for the fundamental limit on the sensitivity of the rf magnetometer and show that a sensitivity of about 0.01 fT/Hz(1/2) can be achieved in a practical system with a measurement volume of 200 cm3. 相似文献
64.
Thieuleux C Quadrelli EA Basset JM Döbler J Sauer J 《Chemical communications (Cambridge, England)》2004,(15):1729-1731
The silica-supported Zr(iv) dihydride [(triple bond)SiO)2ZrH2] reacts quickly and completely with methane to yield [(triple bond)SiO)2ZrMe2] through the intermediate [(triple bond)SiO)2ZrHMe], while its monohydride analogue [(triple bond)SiO)3ZrH] yields the monomethylated product [(triple bond)SiO)3ZrMe] slowly and incompletely. 相似文献
65.
S. Eriksson F. Ramirez-Martinez E.A. Curtis B.E. Sauer P.W. Nutter E.W. Hill E.A. Hinds 《Applied physics. B, Lasers and optics》2004,79(7):811-816
We have produced magnetic patterns suitable for trapping and manipulating neutral atoms on a 1-m length scale. The required patterns are made in Co/Pt thin films on a silicon substrate, using the heat from a focused laser beam to induce controlled domain reversal. In this way we draw lines and paint shaped areas of reversed magnetisation with sub-micron resolution. These structures produce magnetic microtraps above the surface that are suitable for holding rubidium atoms with trap frequencies as high as 1 MHz. PACS 39.25.+k; 03.75.Be; 75.50.Ss; 75.70.-i 相似文献
66.
Dutz H Helbing K Krimmer J Speckner T Zeitler G Ahrens J Altieri S Annand JR Anton G Arends HJ Beck R Bock A Bradtke C Braghieri A v Drachenfels W Frommberger F Godo M Goertz S Grabmayr P Hasegawa S Hansen K Harmsen J Heid E Hillert W Holvoet H Horikawa N Iwata T Van Hoorebeke L d'Hose N Jennewein P Kiel B Klein F Kondratiev R Lang M Lannoy B Leukel R Lisin V Menze D Meyer W Michel T Naumann J Panzeri A Pedroni P Pinelli T Preobrajenski I Radtke E Reicherz G Rohlof C Rostomyan T Sauer M 《Physical review letters》2003,91(19):192001
To verify the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the first time experimentally, we measured the helicity dependent total photoabsorption cross section with circularly polarized real photons and longitudinally polarized nucleons in the photon energy range 0.68-1.82 GeV with the tagged photon facility at ELSA. The experiment was carried out with a 4pi detection system, a circularly polarized tagged photon beam, and a frozen spin polarized proton target. The contribution to the GDH sum rule in this photon energy range is [49.9+/-2.4(stat)+/-2.2(syst)] microb. 相似文献
67.
Sauer T 《Chaos (Woodbury, N.Y.)》2003,13(3):947-952
A general methodology is described for constructing systems that have a slowly converging Lyapunov exponent near zero, based on one-dimensional maps with chaotic attractors. In certain parameter ranges, these relatively simple systems display the properties of intermittent dynamics known as chaotic itinerancy. We show that in addition to the local sensitivity characteristic of chaotic dynamics, these itinerant systems display a global sensitivity, in the sense that fine-scale additive noise may significantly change the natural measure on the large scale. 相似文献
68.
Norbert Sauer 《Combinatorica》2001,21(2):293-308
Dedicated to the memory of Paul Erdős
Erdős, Hajnal and Pósa exhibited in [1] a partition (U,D) of the edges of the Rado graph which is a counterexample to . They also obtained that if every vertex of a graph has either in or in the complement of finite degree then .
We will characterize all graphs so that .
Received October 29, 1999
RID="†"
ID="†" Supported by NSERC of Canada Grant #691325. 相似文献
69.