860 research outputs found
Beyond the Born-Oppenheimer approximation: high-resolution overtone spectroscopy of H2D+ and D2H+
Transitions to overtone 2v2 and 2v3, and combination v2 + v3 vibrations in jet-cooled H2D+ and D2H+ molecular ions have been measured for the first time by high-resolution IR spectroscopy. The source of these ions is a pulsed slit jet supersonic discharge, which allows for efficient generation, rotational cooling, and high frequency (100 KHz) concentration modulation for detection via sensitive lock-in detection methods. Isotopic substitution and high-resolution overtone spectroscopy in this fundamental molecular ion permit a systematic, first principles investigation of Born–Oppenheimer "breakdown" effects due to large amplitude vibrational motion as well as provide rigorous tests of approximate theoretical methods beyond the Born–Oppenheimer level. The observed overtone transitions are in remarkably good agreement (<0.1 cm–1) with non-Born–Oppenheimer ab initio theoretical predictions, with small but systematic deviations for 2v2, 2v + 3v, and 2v3 excited states indicating directions for further improvement in such treatments. Spectroscopic assignment and analysis of the isotopomeric transitions reveals strong Coriolis mixing between near resonant 2v3 and 2v + 3v vibrations in D2H+. Population-independent line intensity ratios for transitions from common lower states indicate excellent overall agreement with theoretical predictions for D2H+, but with statistically significant discrepancies noted for H2D+. Finally, H2D+ versus D2H+ isotopomer populations are analyzed as a function of D2/H2 mixing ratio and can be well described by steady state kinetics in the slit discharge expansion
Interest identification from browser tab titles: A systematic literature review
Modeling and understanding users interests has become an essential part of our daily lives. A variety of business processes and a growing number of companies employ various tools to such an end. The outcomes of these identification strategies are beneficial for both companies and users: the former are more likely to offer services to those customers who really need them, while the latter are more likely to get the service they desire. Several works have been carried out in the area of user interests identification. As a result, it might not be easy for researchers, developers, and users to orient themselves in the field; that is, to find the tools and methods that they most need, to identify ripe areas for further investigations, and to propose the development and adoption of new research plans. In this study, to overcome these potential shortcomings, we performed a systematic literature review on user interests identification. We used as input data browsing tab titles. Our goal here is to offer a service to the readership, which is capable of systematically guiding and reliably orienting researchers, developers, and users in this very vast domain. Our findings demonstrate that the majority of the research carried out in the field gathers data from either social networks (such as Twitter, Instagram and Facebook) or from search engines, leaving open the question of what to do when such data is not available
Cole-Hopf Like Transformation for Schr\"odinger Equations Containing Complex Nonlinearities
We consider systems, which conserve the particle number and are described by
Schr\"odinger equations containing complex nonlinearities. In the case of
canonical systems, we study their main symmetries and conservation laws. We
introduce a Cole-Hopf like transformation both for canonical and noncanonical
systems, which changes the evolution equation into another one containing
purely real nonlinearities, and reduces the continuity equation to the standard
form of the linear theory. This approach allows us to treat, in a unifying
scheme, a wide variety of canonical and noncanonical nonlinear systems, some of
them already known in the literature. pacs{PACS number(s): 02.30.Jr, 03.50.-z,
03.65.-w, 05.45.-a, 11.30.Na, 11.40.DwComment: 26 pages, no figures, to be appear in J. Phys. A: Math. Gen. (2002
The NuMI Neutrino Beam and Potential for an Off-Axis Experiment
The Neutrinos at the Main Injector (NuMI) facility at Fermilab is under
construction and due to begin operations in late 2004. NuMI will deliver an
intense beam of variable energy 2-20 GeV directed into the Earth at
58 mrad. Several aspects of the design are reviewed, and potential limitations
to the ultimate neutrino flux are described. In addition, potential
measurements of neutrino mixing properties are described.Comment: talk given at NuFact '02, Imperial College London, proceedings to
appear in J. Phys. G, revised to add a referenc
Comment on ``the Klein-Gordon Oscillator''
The different ways of description of the particle with oscillator-like
interaction are considered. The results are in conformity with the previous
paper of S. Bruce and P. Minning.Comment: LaTeX file, 5p
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