645 research outputs found
Parameters of CO2 bands near 3.6 microns
The intensities, widths, and positions of lines of three CO2 bands near 2750/cm were determined. The results are in general agreement with other measured and estimated values
A spectrum of carbon dioxide from 800 to 5500 cm-1
An atlas of CO2 lines obtained from long path length samples at 296 K is presented. Many of the line centers are marked and their positions tabulated
Simultaneous retrieval of atmospheric temperatures and ray paths from occultation spectra
Simulated equivalent width data of weak lines in solar occultation spectra were analyzed to retrieve both the solar atmospheric temperature profile and the tangent heights of the rays. It was assumed that the mixing ratio of the absorbing gas was known, but it is not necessary to know the satellite height. By analyzing lines with temperature dependent and temperature independent intensities, temperatures accurate to 1 K and tangent heights to 0.25 km were determined over the range 20 to 90 km
A Kohn-Sham system at zero temperature
An one-dimensional Kohn-Sham system for spin particles is considered which
effectively describes semiconductor {nano}structures and which is investigated
at zero temperature. We prove the existence of solutions and derive a priori
estimates. For this purpose we find estimates for eigenvalues of the
Schr\"odinger operator with effective Kohn-Sham potential and obtain
-bounds of the associated particle density operator. Afterwards,
compactness and continuity results allow to apply Schauder's fixed point
theorem. In case of vanishing exchange-correlation potential uniqueness is
shown by monotonicity arguments. Finally, we investigate the behavior of the
system if the temperature approaches zero.Comment: 27 page
A spectrum of methane from 700 to 5500 cm-1
An atlas of CH4 lines between 700 and 5,500 cm(-1) obtained from long-path-length samples at 296 K is presented. Many of the line centers are marked and their positions tabulated
Recommended from our members
The European Climate Research Alliance (ECRA): collaboration from bottom-up
The European Climate Research Alliance (ECRA) is an association of leading European research institutions in the field of climate research (http://www.ecra-climate.eu/, last access: 6 December 2018). ECRA is a bottom-up initiative and helps to facilitate the development of climate change research, combining the capacities of national research institutions, and inducing closer ties between existing national research initiatives, projects and infrastructures. ECRA works as an open platform to bring together climate researchers, providing excellent scientific expertise for policy makers and of societal relevance. The ECRA Board consists of representatives of ECRA partners and decides on governance, scientific priorities, and organisational matters.
Currently organized into four Collaborative Programmes, climate scientists share their knowledge, experience and expertise to identify the most important research requirements for the future, thus developing a foresight approach. The CPs cover the topics: (1) Arctic variability and change, (2) Sea level changes and coastal impacts, (3) Changes in the hydrological cycle and (4) High impact events. The CP activities are planned in workshops and participation is open to all interested scientists from the relevant research fields. In particular, young researchers are actively encouraged to join the network. Each CP develops its joint research priorities for shaping European research into the future. Because scientific themes are interconnected, the four Collaborative Programmes interact with each other, e.g. through the organization of common workshops or joint applications. In addition, the Collaborative Programme leads attend the Board meetings.
The different formats of ECRA meetings range from scientific workshops to briefing events and side events at conferences to involve different groups of interests. This facilitates the interaction of scientists, various stakeholder groups and politicians. A biennial open ECRA General Assembly that is organised in Brussels represents an umbrella event and acts as a platform for discussion and contact with stakeholders. This event is an excellent opportunity to jointly discuss research priorities of high societal relevance
Molecular and epidemiologic analysis of dengue virus isolates from Somalia.
Nucleotide sequence analysis was performed on 14 dengue virus isolates (13 dengue-2 viruses and 1 dengue-3 virus) recovered from febrile soldiers in Somalia in 1993. The dengue-2 viruses were most closely related to dengue-2 virus recovered in Somalia in 1984. However, differences in nucleotide sequence (0.35% to 1.35%) were evident among the 1993 isolates. These differences were closely associated with the geographic location of the infection as well as with different times of infection at the same location. Genetic difference between strains was not associated with differences in clinical features. Molecular analysis of dengue viruses is a useful adjunct to epidemiologic investigation of their distribution over distance and time
Identifying phase synchronization clusters in spatially extended dynamical systems
We investigate two recently proposed multivariate time series analysis
techniques that aim at detecting phase synchronization clusters in spatially
extended, nonstationary systems with regard to field applications. The starting
point of both techniques is a matrix whose entries are the mean phase coherence
values measured between pairs of time series. The first method is a mean field
approach which allows to define the strength of participation of a subsystem in
a single synchronization cluster. The second method is based on an eigenvalue
decomposition from which a participation index is derived that characterizes
the degree of involvement of a subsystem within multiple synchronization
clusters. Simulating multiple clusters within a lattice of coupled Lorenz
oscillators we explore the limitations and pitfalls of both methods and
demonstrate (a) that the mean field approach is relatively robust even in
configurations where the single cluster assumption is not entirely fulfilled,
and (b) that the eigenvalue decomposition approach correctly identifies the
simulated clusters even for low coupling strengths. Using the eigenvalue
decomposition approach we studied spatiotemporal synchronization clusters in
long-lasting multichannel EEG recordings from epilepsy patients and obtained
results that fully confirm findings from well established neurophysiological
examination techniques. Multivariate time series analysis methods such as
synchronization cluster analysis that account for nonlinearities in the data
are expected to provide complementary information which allows to gain deeper
insights into the collective dynamics of spatially extended complex systems
A 2-terminal perovskite/silicon multijunction solar cell enabled by a silicon tunnel junction
With the advent of efficient high-bandgap metal-halide perovskite photovoltaics, an opportunity exists to make perovskite/silicon tandem solar cells. We fabricate a monolithic tandem by developing a silicon-based interband tunnel junction that facilitates majority-carrier charge recombination between the perovskite and silicon sub-cells. We demonstrate a 1 cm[superscript 2] 2-terminal monolithic perovskite/silicon multijunction solar cell with a V [subscript OC] as high as 1.65 V. We achieve a stable 13.7% power conversion efficiency with the perovskite as the current-limiting sub-cell, and identify key challenges for this device architecture to reach efficiencies over 25%.Bay Area Photovoltaic Consortium (Contract DE-EE0004946)United States. Dept. of Energy (Contract DE-EE0006707
- …