A5061469141- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Chemical Physics Studies
- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Ion-surface interactions and analysis
- Inorganic Fluorides and Related Compounds
- High voltage insulation and dielectric phenomena
- Advanced Fiber Laser Technologies
- Photosynthetic Processes and Mechanisms
- Metal and Thin Film Mechanics
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and devices
- Semiconductor Lasers and Optical Devices
- Spectroscopy and Laser Applications
- Lightning and Electromagnetic Phenomena
- Thermal Analysis in Power Transmission
- nanoparticles nucleation surface interactions
- Advanced Battery Technologies Research
- Plant responses to elevated CO2
- Ferroelectric and Negative Capacitance Devices
- Electric and Hybrid Vehicle Technologies
- Physics and Engineering Research Articles
- Advanced X-ray and CT Imaging
National Physical Laboratory
2019-2024
University of Oxford
2022-2023
Imec the Netherlands
2010
ASM International
2008
Karlsruhe Institute of Technology
2005-2006
University of Regensburg
2004
University of Stuttgart
2002-2003
University of Konstanz
1982-1987
Queen's Medical Centre
1984
This contribution is a practical guide to the measurement of different chlorophyll (Chl) fluorescence parameters and gives examples their development under high-irradiance stress. From Chl induction kinetics upon irradiation dark-adapted leaves, measured with PAM fluorometer, various parameters, ratios, quenching coefficients can be determined, which provide information on functionality photosystem 2 (PS2) photosynthetic apparatus. These are Fv, Fm, F0, Fm', Fv', NF, ΔF, ratios Fv/Fm, Fv/F0,...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron attachment to water clusters under collision-free conditionsMartin. Knapp, Olof. Echt, Dietmar. Kreisle, and Ekkehard. RecknagelCite this: J. Phys. Chem. 1987, 91, 10, 2601–2607Publication Date (Print):May 1, 1987Publication History Published online1 May 2002Published inissue 1 1987https://pubs.acs.org/doi/10.1021/j100294a031https://doi.org/10.1021/j100294a031research-articleACS PublicationsRequest reuse permissionsArticle...
Long-lived water cluster anions [(H2O)−n, n≥11, and (D2O)−n, n≥12] can be formed by electron attachment to a beam of preformed, neutral clusters; collisional stabilization is not required. Attachment occurs resonantly at or very close 0 eV incident energy; the ion yield unexpectedly large.
Size distributions of fragments from multiply charged clusters have been determined. On a time scale 0.1 ms with respect to ionization, triply C${\mathrm{O}}_{2}$ size $n\ensuremath{\approx}114$ are found fission extremely asymmetrically, their doubly carrying 92% the mass. For clusters, however, evaporation neutral monomers is only channel for delayed dissociation. A model, based on liquid-drop approximation, can quantitatively account lower limits as well distribution (C${\mathrm{O}}_{2}$)...
Abstract Mass spectra of xenon clusters show pronounced intensity maxima for cluster sizes n * = 13, 19, 25, 55, 71, 87, and 147. The occurrence these “magic numbers” is explained by shell closure growing in the icosahedral structure. Magic numbers mass 1,2‐dichlorotetra‐fluoroethane are 13 19. only maximum sulfurhexafluoride occurs at whereas a minimum observed 18. In contrast, size distributions 17 other molecular gases decrease strictly monotonically with increasing size. origin effects discussed.
The evaporation of monomers following electron-impact ionization causes a significant enhancement the intensity anomalies (``magic numbers'') in mass spectra xenon clusters. dissociation rates are measured on microsecond time scale for clusters containing between 10 and 79 atoms. highest probability, 99(1)%, is found ${\mathrm{Xe}}_{57}$${\mathrm{}}^{+}$, which two atoms larger than closed-shell icosahedral cluster. Each anomaly corresponds to an number'') spectrum. Recent Monte Carlo...
We report on the characterization and analysis of a GaN-based distributed feedback laser diode (DFB-LD) with 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> -order laterally etched sidewall gratings centered at wavelength 420 nm. also compare device parameters two commonly used Fabry-Perot (FP) devices operating 450 nm 520 Intrinsic properties were extracted, including damping factor, carrier photon lifetimes, modulation efficiency,...
This article describes a novel CVD process for TiN films developed in 300 mm Vertical Furnace. We have solved Chlorine incorporation at low temperature inside the layer while same time batch yields 3 times higher throughput per dual reactor system compared to single wafer with chambers.We show results load sizes ranging from 5 as much 100 wafers that prove filler are only required minimum. Applications of Metal-Insulator-Metal memory devices such Deep Trench DRAM, Stack well Control...
Quantum technologies containing key GaN laser components will enable a new generation of precision sensors, optical atomic clocks and secure communication systems for many applications such as next navigation, gravity mapping timing since the AlGaInN material system allows diodes to be fabricated over wide range wavelengths from u.v. visible. We report our latest results on diode-lasers targeted meet linewidth, wavelength power requirements suitable quantum sensors cold-atom interferometry...
Quantum technologies containing key GaN laser components will enable a new generation of precision sensors, optical atomic clocks and secure communication systems for many applications such as next navigation, gravity mapping timing since the AlGaInN material system allows diodes to be fabricated over wide range wavelengths from U.V. visible. We report our latest results on diode-lasers targeted meet linewidth, wavelength power requirements suitable quantum sensors cold-atom interferometry...
There is an ever-growing requirement for compact atomic devices, such as optical clocks, taking them from a labscale technology to more robust solution. Optical clocks have made significant advances over the last few decades and represent pinnacle of precision measurement technology. However, many systems make use large, expensive lasers which are power hungry often frequency doubled hit key wavelengths or alternatively rely on vibration sensitive external cavity diode (ECDL). New approaches...
To suppress the reactivity of nanoscaled non-oxidic powders titanium nitride (TiN) and silicon carbonitride (SiCN) against hydrolysis oxidation, chemical surface modification with nitrogen-containing surfactants was investigated. Among these surfactants, long-chain primary amines, ethylenediamines, guanidines, nitriles, isocyanates, succinimides were examined. Thermogravimetry, elemental analysis, behavior water-vapor adsorption modified particles used as methods to estimate protective...
Quantum technologies containing key GaN laser components will enable a new generation of precision sensors, optical atomic clocks and secure communication systems for many applications such as next navigation, gravity mapping timing since the AlGaInN material system allows diodes to be fabricated over wide range wavelengths from U.V. visible. We report our latest results on diode-lasers targeted meet linewidth, wavelength power requirements suitable quantum sensors cold-atom interferometry...
Abstract Position, navigation and timing capability worldwide is predominantly underpinned by global satellite systems (GNSS), which provide the underlying for critical national infrastructures, science, industry, commerce society. Recently, vulnerability of such to interference, whether intentional or not, instrument failure space weather, has been recognised, pointing need alternative independent solutions. In particular, availability low size, weight power (low-SWaP) traceable portable...