نتایج جستجو برای: electron impact
تعداد نتایج: 1057079 فیلتر نتایج به سال:
We propose a new technique for the detection of single atoms in ultracold quantum gases. The technique is based on scanning electron microscopy and employs the electron impact ionization of trapped atoms with a focussed electron probe. Subsequent detection of the resulting ions allows for the reconstruction of the atoms position. This technique is expected to achieve a much better spatial resol...
Between 2001 and 2003 the London Health Commission undertook health impact assessments (HIAs) on a series of strategies developed by the Greater London Authority and the Mayor of London. The HIAs were rapid, each involving a literature review and a participant workshop. In all cases the reports made a series of recommendations that were given to the Mayor. The HIAs led to changes and ensured th...
Trait-based approaches provide a mechanistic framework to understand and predict the structure and functioning of microbial communities. Resource utilization traits and trade-offs are among key microbial traits that describe population dynamics and competition among microbes. Several important trade-offs have been identified for prokaryotic and eukaryotic microbial taxa that define contrasting ...
This paper presents a critical analysis of health impact assessment (HIA) in the Republic of Ireland (ROI) in the context of institutional policy and practice. It begins with a brief background to the origins and aims of HIA. Core developments in health and environmental sectors pertaining to HIA in the ROI are then considered. A series of significant developments have taken place in these sect...
Aims. To calculate transition rates from ground and excited states in neutral oxygen atoms due to electron collisions for non-LTE modelling of oxygen in late-type stellar atmospheres, thus enabling reliable interpretation of oxygen lines in stellar spectra. Methods. A 38-state R-matrix calculation in LS -coupling has been performed. Basis orbitals from the literature (Thomas et al.) are adopted...
Process-induced strain dependence of impact ionization efficiency (IIE) in nMOSFETs with a tensile contact etch stop layer (CESL) is presented for the first time. From the universal relationship between the IIE and the electric field in the pinch-off region, a difference in the IIE of nMOSFETs between without and with the tensile CESL is found. This result can be mainly attributed to the narrow...
An analytical treatment of the electron screening effect within an active-electron model is given for positronium formation from helium atoms. A first-order distorted wave approximation with correct boundary conditions is applied to evaluate the transition amplitude. In the range of impact energy for which the introduced perturbative approach is valid, both the total and differential cross sect...
We measured absolute partial cross sections for the formation of various singly charged and doubly charged positive ions produced by electron impact on silicon tetrachloride (SiCl4) using two different experimental techniques, a time-of-flight mass spectrometer (TOF-MS) and a fast-neutral-beam apparatus. The energy range covered was from the threshold to 900 eV in the TOF-MS and to 200 eV in th...
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