We study a femtosecond Ti：sapphire laser pumped optical parametric amplifier （OPA） at 1053nm. The OPA Generates stable signal pulses with duration smaller than l OOfs, wavelength drift smaller than 0.5 nm, and puls...
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We study a femtosecond Ti：sapphire laser pumped optical parametric amplifier （OPA） at 1053nm. The OPA Generates stable signal pulses with duration smaller than l OOfs, wavelength drift smaller than 0.5 nm, and pulseto-pulse fluctuation of about ±4%, by employinG an external seeder. In a terawatt laser pumped large-aperture LiNbOa OPA, pulse energy at signal has been scaled up to 4mJ. This m J-class femtosecond OPA at 1053nm presents a feasible alternative to optical parametric chirped-pulse amplification, and is ready to be applied to petawatt lasers.
We demonstrate a compact pulse shaping system based on temporal stacking of pulses in fibres,by which synchronized pulses of ultrashort and nanosecond lasers can be *** system may generate shape-controllable pulses wi...
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We demonstrate a compact pulse shaping system based on temporal stacking of pulses in fibres,by which synchronized pulses of ultrashort and nanosecond lasers can be *** system may generate shape-controllable pulses with a fast rise time and high-resolution within a time window of -2.2ns by adjusting variable optical attenuators in the 32 fibre channels *** the help of optical amplifiers,the system delivers mJ-level pulses with a signal-to-noise ratio of-35dB.
On p. 2603, Tom Picraux and co‐workers report on the use of plasma excitation to strongly enhance the nucleation of Si nanowires by the vapor–liquid–solid growth method. This control allows the preferential fo...
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On p. 2603, Tom Picraux and co‐workers report on the use of plasma excitation to strongly enhance the nucleation of Si nanowires by the vapor–liquid–solid growth method. This control allows the preferential formation of very small diameter [110] oriented nanowires, as well as significant enhancements in low temperature nanowire growth.
The particle size effect on the peritectic melting of FeSn2 particles in FeSn-FeSn2 nanocomposites was studied using differential scanning calorimetry and X-ray diffraction. FeSn-10 wt.% FeSn2 compounds, mechanically ...
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We report on a detailed analysis of the transport properties and superconducting critical temperatures of boron-doped diamond films grown along the {100} direction. The system presents a metal-insulator transition (MI...
We report on a detailed analysis of the transport properties and superconducting critical temperatures of boron-doped diamond films grown along the {100} direction. The system presents a metal-insulator transition (MIT) for a boron concentration (nB) on the order of nc∼4.5×1020cm−3, in excellent agreement with numerical calculations. The temperature dependence of the conductivity and Hall effect can be well described by variable range hopping for nBnc) present a superconducting transition at low temperature. The zero-temperature conductivity σ0 deduced from fits to the data above the critical temperature (Tc) using a classical quantum interference formula scales as σ0∝(nB∕nc−1)ν with ν∼1. Large Tc values (⩾0.4K) have been obtained for boron concentration down to nB∕nc∼1.1 and Tc surprisingly mimics a (nB∕nc−1)1∕2 law. Those high Tc values can be explained by a slow decrease of the electron-phonon coupling parameter λ and a corresponding drop of the Coulomb pseudopotential μ* as nB→nc.
While the first reported fullerenes and nanotube structureswere composed ofcarbon, it was soon recognized that aplethora of comparable inorganic candidates should alsoexist.[1-3] Because nanoparticles of compounds wit...
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While the first reported fullerenes and nanotube structureswere composed ofcarbon, it was soon recognized that aplethora of comparable inorganic candidates should alsoexist.[1-3] Because nanoparticles of compounds with a layered(2D) structure are unstable againstfolding, they should beable to form nanotubes and closed-cage inorganic fullerenelike(IF)structures. The first such nanostructures were identifiedin WS2[4] and MoS2.[5] A rich assortment ofIF nanostructureshave been synthesized, and are finding practical uses intribology, photonics,batteries, and catalysis.[6]
This paper explores the development of and pilot study done on an online textbook and research tool, based on the book, "how to model it", by Starfield, Smith and Bleloch. In many engineering design texts, t...
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This paper explores the development of and pilot study done on an online textbook and research tool, based on the book, "how to model it", by Starfield, Smith and Bleloch. In many engineering design texts, the solution(s) to design problems are provided in the pages following the proposed problem. With this online system, students are able to read only a portion of the text, and then must complete one or more tasks for which they submit a response to the system. This approach forces the students to begin practicing the engineering design process, rather than simply reading about someone else's design process. As a research tool, the computerized method of data gathering addresses the issue of increasing sampling frequency without much larger investment in research time, as no transcription is required. The small pilot study showed students' responses included data on their design process thinking as well as their proposed solution to the problems
Pb(DPM)2 and Pb(TMOD)2 dissolved in ethylcyclohexane were evaluated as precursors for future atomic layer deposition (ALD) of Pb(Zr,Ti)O3 films. PbO films were deposited by a liquid injection atomic layer deposition o...
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Pb(DPM)2 and Pb(TMOD)2 dissolved in ethylcyclohexane were evaluated as precursors for future atomic layer deposition (ALD) of Pb(Zr,Ti)O3 films. PbO films were deposited by a liquid injection atomic layer deposition on Pt-covered Si substrates at different deposition temperature and precursor volume per cycle. Pb(DPM)2 and Pb(TMOD)2 started thermal decomposition at deposition temperature of around 270ºC and 320ºC, respectively. Against increasing Pb(DPM)2 injection at 240ºC, the deposition rate of PbO films saturated at around 1 Å/cycle, but kept increasing at 300ºC, which is above the thermal decomposition temperature. The deposition rate of PbO films at 240ºC dropped to a constant value with enough purge time after precursor injection and reactant supply. A saturated deposition rate of PbO films was also observed for Pb(TMOD)2 below the thermal decomposition temperature. However, the saturation behavior observed for Pb(TMOD)2 was slower and the saturated growth rate was higher comparing to Pb(DPM)2. In addition, the film thickness of the PbO films had an apparent gradient over the substrates. These results indicate that Pb(DPM)2 shows more reactive and stable chemisorption comparing to Pb(TMOD)2 for the self-limiting growth rate.
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