ALBERT

Description: This review summarizes the recent advances in three-dimensional (3D) imaging techniques and their application to polymer nanostructures, for example, microphase-separated structures of block copolymers. We place particular emphasis on the method of transmission electron microtomography (electron tomography for short; hereafter abbreviated as ET). As a result of recent developments in ET, truly quantitative 3D images of polymer nanostructures can now be obtained with subnanometer resolution. The introduction of scanning optics in ET has made it possible to obtain large amounts of 3D data from micrometer-thick polymer specimens by using conventional electron microscopes at a relatively low accelerating voltage, 200 kV. Thus, ET covers structures over a wide range of thicknesses, from a few nanometers to several hundred nanometers, which corresponds to quite an important spatial range for hierarchical polymer nanostructures. ET provides clear 3D images and a wide range of new structural information that cannot be obtained using other methods. Information traditionally derived from conventional microscopy or scattering methods can be directly acquired from 3D volume data. ET is a versatile technique that is not restricted to only polymer applications; it can also be used as a powerful characterization tool in energy applications such as fuel cells.

Description: The ultrastructure of melanin granules in human hair was studied using 1,000 kV high-voltage scanning transmission electron microscopy to successfully reconstruct three-dimensional images of the whole melanin granule. It was revealed that the melanin granule was composed of a membrane-like outer structure that included many spherical vesicles, and an inner matrix containing a sheet-like structure in the elongated direction of the melanin granule and a sheet-like arrays structure in the cross direction. The outer structure of the melanin granule was maintained even after exposure to hair-bleaching agents to decompose the melanin granule, suggesting that the outer structure was a highly robust structure and composition compared with the inner matrix .

Description: We reproduce a magnetospheric reconfiguration under southward interplanetary magnetic field (IMF) conditions using numerical magnetohydrodynamic simulations. To investigate the relative displacements of the geomagnetic conjugate points, we trace both footprints of the geomagnetic field lines during the magnetospheric reconfiguration under positive and negative IMF By conditions. Several substormlike features, namely, the formation of a near-Earth neutral line, a fast earthward flow, and tailward releases of the plasmoid, occur about 1 h after a southward turning of the IMF. The surveyed field line traced from the near-Earth magnetotail was strongly distorted duskward in the north and south after the substorm onset for positive and negative IMF By, respectively. The maximum of the relative longitudinal displacement of both footprints is 4.5 and 5.5 h in magnetic local time for positive and negative IMF By, respectively. While observational studies have indicated that the IMF orientation is the main factor controlling the relative displacement of the conjugate points, the present simulation-based study with a constant IMF orientation shows for the first time that the combined effects of plasma pressure, magnetic field intensity, and the field-aligned current density distribution along the field line are likely to be major factors controlling the relative displacement of conjugate points.

Description: Author(s): T. Higuchi et al. (The Belle Collaboration) We report a new sensitive search for C P T violation, which includes improved measurements of the C P T -violating parameter z and the total decay-width difference normalized to the averaged width Δ Γ d / Γ d of the two B d mass eigenstates. The results are based on a data sample of 535×10 6 B B ̅ pairs c... [Phys. Rev. D 85, 071105] Published Wed Apr 25, 2012

Description: Interfaces in heterostructures composed of two different transition-metal oxides are now a strongly growing research topic in condensed-matter physics due to the anomalous electronic properties very different from those of the component materials. Here we present resonant soft x-ray scattering studies of SrTiO 3 /LaAlO 3 superlattices. From the existence of the forbidden Bragg peak (003), we found evidence for differences between the bulk and the interface electronic structures. The photon-energy dependence near the O 1 s edge and polarization dependence showed that there are two structures split by ~ 1 eV, which were not observed in the O 1 s x-ray absorption spectrum. The origin of this splitting is still unclear, but we consider that this is not only due to the splitting of t 2 g states at the interface but also due to the difference between the O 1 s binding energies for bulk and interface oxygen.

Description: We have developed a technique by which to estimate the spatial distribution of plasmaspheric helium ions based on extreme ultraviolet (EUV) data obtained from the IMAGE satellite. The estimation is performed using a linear inversion method based on the Bayesian approach. The global imaging data from the IMAGE satellite enables us to estimate a global two-dimensional distribution of the helium ions in the plasmasphere. We applied this technique to a synthetic EUV image generated from a numerical model. This technique was confirmed to successfully reproduce the helium ion density that generated the synthetic EUV data. We also demonstrate how the proposed technique works for real data using two real EUV images.

Description: We have developed a technique for estimating the temporal evolution of the plasmaspheric helium ion density based on a sequence of extreme ultraviolet (EUV) data obtained from the IMAGE satellite. In the proposed technique, the estimation is obtained by incorporating EUV images from IMAGE into a two-dimensional fluid model of the plasmasphere using a data assimilation approach based on the ensemble transform Kalman filter. Since the motion and the spatial structure of the helium plasmasphere is strongly controlled by the electric field in the inner magnetosphere, the electric field around the plasmapause can also be estimated using the ensemble transform Kalman filter. We performed an experiment using synthetic images that were generated from the same numerical model under a certain condition. It was confirmed that the condition that generated the synthetic images was successfully reproduced. We also present some results obtained using real EUV imaging data. Finally, we discuss the possibility of estimating the density profile along a magnetic field line. Since each EUV image was taken from a different direction due to the motion of the IMAGE satellite, we could obtain the information on the density profile along a field line by combining multiple images.

Description: [1]  In the present study we observationally address the role of ionospheric conductivity in the solar wind-magnetosphere coupling in terms of global field-aligned currents (FACs). Solar EUV irradiance changes during a solar cycle, and so does its contribution to the ionospheric conductivity. We statistically examine how, under fixed external conditions, the intensities of the R1 and R2 currents and their demarcation latitude depend on solar activity (F10.7). An emphasis is placed on nightside FACs in the dark hemisphere. The result shows that for fixed ranges of interplanetary electric field, the nightside FACs are more intense for higher solar activity irrespective of their polarities or local times. It is also found that the R1-R2 pair, therefore the auroral oval, moves equatorward as the solar activity increases. For both current intensity and latitude, the dependence on F10.7 is more sensitive at smaller F10.7 and it levels off with increasing F10.7. The intensities of dayside FACs reveal similar F10.7 dependence as expected from the enhancement of the local ionospheric conductance. Interestingly, they also move equatorward with increasing solar activity. It is expected from force balance that as the dayside R1 current becomes more intense with increasing solar activity, the magnetosphere shrinks on the day side and expands on the night side. This configurational change of the magnetosphere presumably affects the energy transport from the solar wind to the magnetosphere, although its details still remain to be understood. We conclude that the ionospheric conductivity actively affects the solar wind-magnetosphere-ionosphere coupling.

Description: Invariance under the charge, parity, time-reversal (CPT) transformation is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry--that is, the laws of nature seem to be invariant under the symmetry transformation of spacetime--although it is model dependent. A number of high-precision CPT and Lorentz invariance tests--using a co-magnetometer, a torsion pendulum and a maser, among others--have been performed, but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available. Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H(-)) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton (q/m)p- to that for the proton (q/m)p and obtain (q/m)p-/(q/m)p - 1 =1(69) x 10(-12). The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-to-proton mass comparisons as well as the respective figure of merit of the standard model extension by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of 〈720 parts per trillion. By following the arguments of ref. 11, our result can be interpreted as a stringent test of the weak equivalence principle of general relativity using baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of |alpha - 1| 〈 8.7 x 10(-7).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ulmer, S -- Smorra, C -- Mooser, A -- Franke, K -- Nagahama, H -- Schneider, G -- Higuchi, T -- Van Gorp, S -- Blaum, K -- Matsuda, Y -- Quint, W -- Walz, J -- Yamazaki, Y -- England -- Nature. 2015 Aug 13;524(7564):196-9. doi: 10.1038/nature14861.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉RIKEN, Ulmer Initiative Research Unit, Wako, Saitama 351-0198, Japan. ; 1] RIKEN, Ulmer Initiative Research Unit, Wako, Saitama 351-0198, Japan [2] CERN, CH-1211 Geneva, Switzerland. ; 1] RIKEN, Ulmer Initiative Research Unit, Wako, Saitama 351-0198, Japan [2] Max-Planck-Institut fur Kernphysik, 69117 Heidelberg, Germany. ; 1] RIKEN, Ulmer Initiative Research Unit, Wako, Saitama 351-0198, Japan [2] Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan. ; 1] RIKEN, Ulmer Initiative Research Unit, Wako, Saitama 351-0198, Japan [2] Institut fur Physik, Johannes Gutenberg-Universitat, 55099 Mainz, Germany. ; RIKEN, Atomic Physics Laboratory, Wako, Saitama 351-0198, Japan. ; Max-Planck-Institut fur Kernphysik, 69117 Heidelberg, Germany. ; Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan. ; GSI-Helmholtzzentrum fur Schwerionenforschung, 64291 Darmstadt, Germany. ; 1] Institut fur Physik, Johannes Gutenberg-Universitat, 55099 Mainz, Germany [2] Helmholtz Institut Mainz, 55099 Mainz, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26268189" target="_blank"〉PubMed〈/a〉