Stability of the proton-to-electron mass ratio

We report a limit on the fractional temporal variation of the proton-to-electron mass ratio as, obtained by comparing the frequency of a rovibrational transition in SF6 with the fundamental hyperfine transition in Cs. The SF6 transition was accessed using a CO2 laser to interrogate spatial 2-photon Ramsey fringes. The atomic transition was accessed using a primary standard controlled with a Cs fountain. This result is direct and model-free

Afterword: the emergent literature on interdisciplinary and transdisciplinary research evaluation

The complexity of evaluating interdisciplinary (ID) and transdisciplinary (TD) research defies a single standard. Yet, common elements appear in the emergent literature. Five overriding themes stand out. (1) Quality is a relative concept, driven by variability of goals and criteria. (2) A coaching model of evaluation nurtures the research process. (3) Integration is central to the process. (4) Social and cognitive factors interact, requiring management of information and decisionmaking. (5) The need for change in peer review has led to a variety of strategies. ID and TD evaluation is a generative activity that entails acts of “capitalizing” and “harvesting” expertise while “calibrating” standards to produce new “cultures of evidence”

L'éducation primaire, secondaire et postsecondaire aux États-Unis : vers l’unification du discours sur l’interdisciplinarité

Cet article vise à établir un discours commun concernant l'interdisciplinarité à tous les ordres d'enseignement. Il est articulé autour de quatre points. Le contexte historique établit des rapprochements au niveau des tendances, des concepts et des structures apparus au cours du siècle. Le contexte curriculaire compare les structures et les principes organisateurs de différents curriculums; il fait aussi ressortir l'importance des thèmes et des problèmes. Le contexte d'enseignement examine des questions courantes de pédagogie, de processus intégrateurs et de changements institutionnels. Enfin, le contexte de formation à l'enseignement insiste sur la nécessité d'une préparation formelle et d'un développement professionnel continu. Cette étude traite aussi des principaux problèmes et des limites de l'approche interdisciplinaire dont elle présente un aperçu de la documentation publiée en anglais.The aim of this article is to establish a common discourse relating to interdisciplinarity at all levels of education. These are four main comparisons presented. The historical context promotes understandings regarding tendancies, concepts, and structures that have developped during the last century. The curricular context compares structures and organizational principles of different curriculums; underlining the importance of themes and problems. The teaching context examines current questions in pedagogy, in integrative processes and in institutional changes. Finally, the teacher training context stresses the need for formal training and for professional inservice development. This study also examines the main problems and limits relating to the interdisciplinary approach as described in the literature published in English.Este articulo tiene por meta establecer un discurso comiin sobre la interdisciplinariedad en todos los nivelés de ensenanza. Esta articulado alrededor de cuatro puntos. El contexto historico establece los contactos a nivel de tendencias, conceptos y estructuras que han aparecido en el curso de este siglo. El contexto curricular compara las estructuras y principios organizadores de diferentes curriculos, haciendo resaltar asi la importancia de ciertos temas y problemas. El contexto de ensenanza examina cuestiones corrientes de pedagogia, de procesos integradores y de cambio institucional. En fin, el contexto de formacion docente insiste en la necesidad de una preparacion formai y un desarrollo profesional continuo. Este estudio trata también los problemas principales y los limites del enfoque interdisciplinario del cual présenta un resumen de la documentaciôn publicada en inglés.Dieser Artikel versucht, den Begriff der Interdisziplinarität über die verschiedenen Schulstufen hinaus zu vereinheidichen. Er ist um vier Vergleichspunkte gegliedert. Der historische Zusammenhang ermoglicht es, zwischen den im Laufe des 20. Jahrhunderts auftretenden Tendenzen, Begriffe und Strukturen Ähnlichkeiten aufzuweisen. Im zweiten Teil werden die Strukturen und Organisationsprinzipien verschiedener Lehrpläne miteindander verglichen, wobei die Bedeutung der Themen und der Probleme herausgestellt wird. Im dritten Teil handelt es sich um Unterricht; dabei werden Aspekte besprochen beziiglich der Pädagogik, der integrierenden Prozesse und des institutionellen Wandels. Der vierte Vergleichspunkt betrirft die Lehrerbildung; es wird hervorgehoben, dass formelle Vorbereitung und berufliche Fortbildung besonders wichtig sind. Schließlich untersucht der Artikel die wichtigsten Probleme und die Grenzen der interdisziplinären Methode und bespricht kurz die einschlägige Literatur in englischer Sprache

Mott g-Ratios in Rbx(NH3)1-x and Oxidation state of Rubidium Compounds from XAS

The x-ray absorption spectra (XAS) of Rb metal, Rh,( JH,J, ,, 2H-NbSe2Rb111x and RbBr near the Rb K-edge have been used to ascertain that the oxidation state V of rubidium dissolved in ammonia and intt:rcalated in the layer compound is in the range 0 \u3c V \u3c I. Theobservededge shifts with temperature for semimctals are explainedin terms of the population of band states, and the ratio of the density states near the mobility edge over that calculated for a free electron model, i.e. the Mott ratio g, is ascertained using a semiempirical relation developed for the x-ray absorbance from Is levels to empty states ncar the mobility edge

Invariant classification of orthogonally separable Hamiltonian systems in Euclidean space

The problem of the invariant classification of the orthogonal coordinate webs defined in Euclidean space is solved within the framework of Felix Klein's Erlangen Program. The results are applied to the problem of integrability of the Calogero-Moser model

Measurement of Synchrotron x-ray energies and line shapes using diffraction markers

Standard reference markers for accurate, reproducible synchrotron x-ray energies are obtained using a three Si crystal spectrometer. The first two crystals are in the monochromator and the third is used to obtain diffraction markers which monitor the energy. Then for any value of the glancing angle on the reference Si crystal the energy for the (333) diffraction must occur at 3/4 that of the (444) and 3/5 of that for the (555). This establishes for the first time an absolute synchrotron energy scale. Higher-order diffractions are used to determine excitation line profiles. We conclude that the use of reference diffractions is necessary to measure reproducible x-ray energies and to analyze the incident photons\u27 line profile. The detection of diffractions near the edge of measurement and near the Cu edge will provide a fast secondary standard which will allow comparison of edge data between different laboratories. The diffraction profiles will allow the proper analysis of spectral line widths

Magnetic Lensing near Ultramagnetized Neutron Stars

Extremely strong magnetic fields change the vacuum index of refraction. This induces a lensing effect that is not unlike the lensing phenomenon in strong gravitational fields. The main difference between the two is the polarization dependency of the magnetic lensing, a behaviour that induces a handful of interesting effects. The main prediction is that the thermal emission of neutron stars with extremely strong magnetic fields is polarized - up to a few percent for the largest fields known. This potentially allows a direct method for measuring their magnetic fields.Comment: To appear in MNRAS, 12 pages, 9 figure