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Author Aberle, N.; Witte, U.
Title Deep-sea macrofauna exposed to a simulated sedimentation event in the abyssal NE Atlantic: in situ pulse-chase experiments using 13C-labelled phytodetritus Type Journal Article
Year 2003 Publication Marine Ecology Progress Series Abbreviated Journal (up) Mar Ecol Prog Ser
Volume 251 Issue Pages 37-47
Keywords Deep-sea; Pulse-chase experiment; δ13C; Benthic carbon remineralisation; Macrofauna; Atlantic Ocean, Porcupine Abyssal Plain
Abstract Tracer experiments with 13C-labelled diatoms Thalassiosira rotula (Bacillariophycea, 98% 13C-labelled) were conducted at the Porcupine Abyssal Plain (PAP) in the NE Atlantic (BENGAL Station; 48<b0>50'N, 16<b0>30'W, 4850 m depth) during May/June 2000. In situ enrichment experiments were carried out using deep-sea benthic chamber landers: within the chambers a spring bloom was simulated and the fate of this food-pulse within the abyssal macrobenthic community was followed. In focus was the role of different macrofauna taxa and their vertical distribution within the sediment column in consuming and reworking the freshly deposited material. T. rotula is one of the most abundant pelagic diatoms in the NE Atlantic and therefore 0.2 g of freeze dried T. rotula, equivalent to 1 g algal C m-2 yr-1, was injected into each incubation chamber. Three different incubation times of 2.5, 8 and 23 d were chosen in order to follow the uptake of 13C-labelled phytodetritus by macrofauna. After only 2.5 d, 77% of all macrofauna organisms showed tracer uptake. After 23 d the highest degree of enrichment was measured and 95% of the individuals had taken up 13C from the introduced algal material. In addition to that a downward transport of organic matter was observed, even though the mixing was not very intense. The initial processing of carbon was dominated by polychaetes that made up a percentage of 52% of total macrofauna. In general macrofauna organisms that lived close to the sediment surface had higher access to the simulated food-pulse, confirming the hypothesis that individuals close to the sediment surface have the strongest impact on the decomposition of phytodetritus. In our study we observed only modest vertical entrainment of 13C tracers into the sediment. With regard to contradictory results from former 13C-enrichment experiments in bathyal regions, compared to results from our study site in the abyssal plain, we thus propose pronounced differences in feeding strategies between macrofauna communities from continental margins and abyssal plains.
Address Aberle, Witte: Max Planck Institute for Marine Microbiology, Celsiusstr. 1, 28359 Bremen, Germany; Aberle: Present address: Max Planck Institute for Limnology, August-Thienemann-Str. 2, 24306 Pl<f6>n, Germany; Email: aberle@mpil-ploen.mpg.de
Corporate Author Thesis
Publisher Inter-Research Place of Publication Oldendorf/Luhe Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0171-8630 ISBN Medium
Area NE Atlantic Expedition Conference
Notes Approved no
Call Number refbase @ user @ 706 Serial 4
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Author Korneev, A.; Lipatov, A.; Okunev, O.; Chulkova, G.; Smirnov, K.; Gol’tsman, G.; Zhang, J.; Slysz, W.; Verevkin, A.; Sobolewski, R.
Title GHz counting rate NbN single-photon detector for IR diagnostics of VLSI CMOS circuits Type Journal Article
Year 2003 Publication Microelectronic Engineering Abbreviated Journal (up) Microelectronic Engineering
Volume 69 Issue 2-4 Pages 274-278
Keywords NbN SSPD, SNSPD, applications
Abstract We present a new, simple to manufacture superconducting single-photon detector operational in the range from ultraviolet to mid-infrared radiation wavelengths. The detector combines GHz counting rate, high quantum efficiency and very low level of dark (false) counts. At 1.3–1.5 μm wavelength range our detector exhibits a quantum efficiency of 5–10%. The detector photoresponse voltage pulse duration was measured to be about 150 ps with jitter of 35 ps and both of them were limited mostly by our measurement equipment. In terms of quantum efficiency, dark counts level, speed of operation the detector surpasses all semiconductor counterparts and was successfully applied for CMOS integrated circuits diagnostics.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-9317 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1511
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Author Su, M. Y.; Carter, S. G.; Sherwin, M. S.
Title Strong-field terahertz optical mixing in excitons Type Journal Article
Year 2003 Publication Phys. Rev. B Abbreviated Journal (up) Phys. Rev. B
Volume 67 Issue 12 Pages
Keywords optical mixing
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 500
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Author Zhang, J.; Słysz, W.; Pearlman, A.; Verevkin, A.; Sobolewski, R.; Okunev, O.; Chulkova, G.; Gol’tsman, G. N.
Title Time delay of resistive-state formation in superconducting stripes excited by single optical photons Type Journal Article
Year 2003 Publication Phys. Rev. B Abbreviated Journal (up) Phys. Rev. B
Volume 67 Issue 13 Pages 132508 (1 to 4)
Keywords NbN SSPD, SNSPD
Abstract We have observed a 65(±5)-ps time delay in the onset of a resistive-state formation in 10-nm-thick, 130-nm-wide NbN superconducting stripes exposed to single photons. The delay in the photoresponse decreased to zero when the stripe was irradiated by multi-photon (classical) optical pulses. Our NbN structures were kept at 4.2 K, well below the material’s critical temperature, and were illuminated by 100-fs-wide optical pulses. The time-delay phenomenon has been explained within the framework of a model based on photon-induced generation of a hotspot in the superconducting stripe and subsequent, supercurrent-assisted, resistive-state formation across the entire stripe cross section. The measured time delays in both the single-photon and two-photon detection regimes agree well with theoretical predictions of the resistive-state dynamics in one-dimensional superconducting stripes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1519
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Author Anthore, A.; Pothier, H.; Esteve, D.
Title Density of states in a superconductor carrying a supercurrent Type Journal Article
Year 2003 Publication Phys. Rev. Lett. Abbreviated Journal (up) Phys. Rev. Lett.
Volume 90 Issue 12 Pages 127001 (1 to 4)
Keywords Usadel, superconducting nanowire
Abstract We have measured the tunneling density of states (DOS) in a superconductor carrying a supercurrent or exposed to an external magnetic field. The pair correlations are weakened by the supercurrent, leading to a modification of the DOS and to a reduction of the gap. As predicted by the theory of superconductivity in diffusive metals, we find that this effect is similar to that of an external magnetic field.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Recommended by Klapwijk Approved no
Call Number Serial 924
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