cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Strong and ductile high temperature soft magnets through Widmanstätten precipitates
Creators: name: Han, Liuliu
name: Maccari, Fernando
name: Soldatov, Ivan
name: Peter, Nicolas J.
name: Souza Filho, Isnaldi R.
name: Schäfer, Rudolf
name: Gutfleisch, Oliver
name: Li, Zhiming
name: Raabe, Dierk
Publisher: name: [London] : Nature Publishing Group UK
Year: 2023
Subjects: subject: alloy
subject: cobalt
subject: ferromagnetic material
subject: iron
subject: nickel
subject: tantalum
subject: alternative energy
subject: electrification
subject: high temperature
subject: magnetization
subject: mechanical property
subject: strength
subject: Article
subject: biomechanics
subject: coercivity
subject: magnetic parameters
subject: magnetism
subject: physical chemistry
subject: room temperature
subject: tensile strength
subject: thermodynamics
subject: thermostability
subject: Widmanstatten pattern
subject: article
subject: controlled study
subject: electric engine
subject: energy yield
subject: magnet
subject: nonhuman
subject: pharmaceutics
subject: temperature
subject: 500

description: Fast growth of sustainable energy production requires massive electrification of transport, industry and households, with electrical motors as key components. These need soft magnets with high saturation magnetization, mechanical strength, and thermal stability to operate efficiently and safely. Reconciling these properties in one material is challenging because thermally-stable microstructures for strength increase conflict with magnetic performance. Here, we present a material concept that combines thermal stability, soft magnetic response, and high mechanical strength. The strong and ductile soft ferromagnet is realized as a multicomponent alloy in which precipitates with a large aspect ratio form a Widmanstätten pattern. The material shows excellent magnetic and mechanical properties at high temperatures while the reference alloy with identical composition devoid of precipitates significantly loses its magnetization and strength at identical temperatures. The work provides a new avenue to develop soft magnets for high-temperature applications, enabling efficient use of sustainable electrical energy under harsh operating conditions.
MOESM1 of A hybrid method for the imputation of genomic data in livestock populations
Creators: name: AntolĂ­N, Roberto
name: Nettelblad, Carl
name: Gorjanc, Gregor
name: Money, Daniel
name: Hickey, John
Publisher: name: Figshare
Year: 2017
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: 69999 Biological Sciences not elsewhere classified
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics

description: Additional file 1: Figure S1. Real computation time in hours for imputing to a the H10k and b the H2k high-density panels. Subfigures show real times of the hybrid method (blue), AlphaImpute (red) and MaCH (green) imputation methods for different numbers of template haplotypes and iterations (different line styles). AlphaImpute is independent of the number of template haplotypes and iterations, and is shown as a horizontal line.
A Dual-Mode Surface Acoustic Wave Delay Line for the Detection of Ice on 64°-Rotated Y-Cut Lithium Niobate
Creators: name: Schulmeyer, Philipp
name: Weihnacht, Manfred
name: Schmidt, Hagen
Publisher: name: Basel : MDPI
Year: 2024
Subjects: subject: finite-element method (FEM)
subject: ice
subject: lithium niobate
subject: non-destructive testing (NDT)
subject: piezoelectric
subject: Rayleigh wave
subject: sensor
subject: SH-LSAW
subject: surface acoustic wave (SAW)
subject: 620

description: Ice accumulation on infrastructure poses severe safety risks and economic losses, necessitating effective detection and monitoring solutions. This study introduces a novel approach employing surface acoustic wave (SAW) sensors, known for their small size, wireless operation, energy self-sufficiency, and retrofit capability. Utilizing a SAW dual-mode delay line device on a 64°-rotated Y-cut lithium niobate substrate, we demonstrate a solution for combined ice detection and temperature measurement. In addition to the shear-horizontal polarized leaky SAW, our findings reveal an electrically excitable Rayleigh-type wave in the X+90° direction on the same cut. Experimental results in a temperature chamber confirm capability for reliable differentiation between liquid water and ice loading and simultaneous temperature measurements. This research presents a promising advancement in addressing safety concerns and economic losses associated with ice accretion.
MOESM1 of Estimation of genetic connectedness diagnostics based on prediction errors without the prediction error varianceâ  covariance matrix
Creators: name: Holmes, John
name: Dodds, Ken
name: Lee, Michael
Publisher: name: Figshare
Year: 2017
Subjects: subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Evolutionary Biology
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Plant Biology
subject: Computational Biology

description: Additional file 1: Figure S1. A pdf file containing figures showing the differences in PEVMean between when H as opposed to A was used to model $$Var({{\bf u}})$$ V a r ( u ) . First column is diagonal elements, second column is off-diagonal elements. The red line indicates where the element of PEVMean was equal if either H and A was used.
Modeling of the properties of the semiconductor solid solution Lu1-xVxNiSb in the presence of magnetic ordering; [Моделювання властивостей напівпровідникового твердого розчину Lu1-xVxNiSb за наявності магнітного упорядкування]
Creators: name: Romaka, V.V.
name: Romaka, V.A.
name: Stadnyk, Yu.
name: Romaka, L.
name: Horyn, A.
name: Pashkevych, V.
name: Haraniuk, P.
Publisher: name: Ivano-Frankivsʹk : Fizyko-chimičnyj instytut DVNZ "Prykarpatsʹkyj nacionalʹnyj universytet imeni Vasylja Stefanyka"
Year: 2023
Subjects: subject: Curie temperature
subject: Fermi level
subject: magnetic ordering
subject: 530
subject: 540

description: Modeling of the thermodynamic, structural, energetic and magnetic properties of the semiconductor solid solution Lu1-xVxNiSb was carried out under the condition of the presence of a magnetic moment on the V atoms and the occurrence of spontaneous magnetization. It is shown that the change in the unit cell parameter a(x) and the mixing enthalpy ΔHmix(х) depends little on the presence or absence of spontaneous magnetization. Modeling of the distribution of the density of electronic states DOS in the presence of a magnetic moment on V atoms revealed the splitting of energy states with spins up and down while preserving the band gap εg of Lu1-xVxNiSb. The relationship between the concentration of magnetic V atoms in Lu1-xVxNiSb and the Curie temperature ТС, when spontaneous magnetization is destroyed and the substance becomes paramagnetic, is established. The solid solution semiconductor Lu1-xVxNiSb, provided spontaneous magnetization is present, can be considered as a promising magnetocaloric.
Desisa variegata Breuning 1938
Creators: name: Gupta, Rajeev
name: Vitali, Francesco
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy

description: 2. Desisa variegata Breuning, 1938
Desisa variegata Breuning, 1938d: 373.
Type Locality: India: TN, Dharmapuri, Denkanikotra (HT ♀); BMNH. Desisa (Desisa) variegata Breuning, 1961b: 261 (Cat.). Distribution: India (TN: N. Salem, Dharmapuri, Denkanikotra).
Desisa (Cylindrostyrax) Aurivillius, 1911: 212 (type sp.: Cylindrostyrax apomecynoides Aurivillius, 1911); Desisa (Cylindrothorax) Breuning, 1964b: 262 [sic].
description: Published as part of Gupta, Rajeev & Vitali, Francesco, 2017, The checklist of longhorn beetles (Coleoptera: Cerambycidae) from India, pp. 1-317 in Zootaxa 4345 (1) on page 189, DOI: 10.11646/zootaxa.4345.1.1, http://zenodo.org/record/1044137
Coupled mechanical oscillator enables precise detection of nanowire flexural vibrations
Creators: name: Sharma, Maneesha
name: Sathyadharma Prasad, Aniruddha
name: Freitag, Norbert H.
name: Büchner, Bernd
name: Mühl, Thomas
Publisher: name: London : Springer Nature
Year: 2023
Subjects: subject: Electric fields
subject: Laser beams
subject: Oscillistors
subject: Vibrations (mechanical)
subject: Detection methods
subject: Flexural vibrations
subject: Force sensing
subject: High electric fields
subject: Mass sensing
subject: Mechanical oscillators
subject: Optical-
subject: Research areas
subject: Sensitive mass
subject: Ultrasensitive
subject: Nanowires
subject: 530

description: The field of nanowire (NW) technology represents an exciting and steadily growing research area with applications in ultra-sensitive mass and force sensing. Existing detection methods for NW deflection and oscillation include optical and field emission approaches. However, they are challenging for detecting small diameter NWs because of the heating produced by the laser beam and the impact of the high electric field. Alternatively, the deflection of a NW can be detected indirectly by co-resonantly coupling the NW to a cantilever and measuring it using a scanning probe microscope. Here, we prove experimentally that co-resonantly coupled devices are sensitive to small force derivatives similar to standalone NWs. We detect force derivatives as small as 10−9 N/m with a bandwidth of 1 Hz at room temperature. Furthermore, the measured hybrid vibration modes show clear signatures of avoided crossing. The detection technique presented in this work verifies a major step in boosting NW-based force and mass sensing.
Complete field-induced spectral response of the spin-1/2 triangular-lattice antiferromagnet CsYbSe2
Creators: name: Xie, Tao
name: Eberharter, A. A.
name: Xing, Jie
name: Nishimoto, S.
name: Brando, M.
name: Khanenko, P.
name: Sichelschmidt, J.
name: Turrini, A. A.
name: Mazzone, D. G.
name: Naumov, P. G.
name: Sanjeewa, L. D.
name: Harrison, N.
name: Sefat, Athena S.
name: Normand, B.
name: Läuchli, A. M.
name: Podlesnyak, A.
name: Nikitin, S. E.
Publisher: name: [London] : Nature Publishing Group
Year: 2023
Subjects: subject: Excitations
subject: package
subject: 530

description: Fifty years after Anderson’s resonating valence-bond proposal, the spin-1/2 triangular-lattice Heisenberg antiferromagnet (TLHAF) remains the ultimate platform to explore highly entangled quantum spin states in proximity to magnetic order. Yb-based delafossites are ideal candidate TLHAF materials, which allow experimental access to the full range of applied in-plane magnetic fields. We perform a systematic neutron scattering study of CsYbSe2, first proving the Heisenberg character of the interactions and quantifying the second-neighbor coupling. We then measure the complex evolution of the excitation spectrum, finding extensive continuum features near the 120°-ordered state, throughout the 1/3-magnetization plateau and beyond this up to saturation. We perform cylinder matrix-product-state (MPS) calculations to obtain an unbiased numerical benchmark for the TLHAF and spectacular agreement with the experimental spectra. The measured and calculated longitudinal spectral functions reflect the role of multi-magnon bound and scattering states. These results provide valuable insight into unconventional field-induced spin excitations in frustrated quantum materials.
Additional file 1: Figure S1. of Synthesis, Characterization, Luminescent and Nonlinear Optical Responses of Nanosized ZnO
Creators: name: Multian, Volodymyr
name: Uklein, Andrii
name: Zaderko, Alexander
name: Kozhanov, Vadim
name: Boldyrieva, Olga
name: Linnik, Rostyslav
name: Lisnyak, Vladyslav
name: Gayvoronsky, Volodymyr
Publisher: name: Figshare
Year: 2017
Subjects: subject: Biochemistry
subject: Space Science
subject: Medicine
subject: Molecular Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Marine Biology
subject: Hematology
subject: 110309 Infectious Diseases
subject: FOS: Health sciences

description: A typical color change of EtOH (a–c) and (d–e) i-PrOH solutions of Zn(CH3COO)2 × 2H2O, at different stages of the interaction of components: (a) starting solution 1–2 min after the preparation, (b) 30 min, and (c) 1-h heating at 60 °C; (d) 20 min after the preparation, (e) 60 min, and (f) 2-h heating at 60 °C. Figure S2. The starting i-PrOH solution of Zn(CH3COO)2 × 2H2O (a) and (b–c) luminescence of ZnO NP obtained by hydrolysis. Figure S3 a, b. Comparison of UV-Vis spectra of ZnO NP in solutions and solid precipitates. Figure S4. UV-Vis spectra of ZnO NP in the resulted solutions (a) EtOH, (b) i-PrOH, (c) MeCN, and (d) PPG. (PDF 346 kb)
Heliconia (sect. Angustae) W. J. Kress, sect. nov.
Creators: name: Kress, W. John
name: Fér, Tomáš
name: Carlsen, Mónica M.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Zingiberales
Heliconiaceae
Heliconia

description: 1.2. 2.Heliconia section AngustaeW. J. Kress,sect. nov.
Figs 3 G, H
Type.
Heliconia angusta Vell.
Description and taxonomic notes.
Small to medium-sized rhizomatous herbs with Musa - like habit. Inflorescence erect, with peduncle, rachis and cincinnal bracts colored primarily red; cincinnal bracts distichous usually held erect at 60–90 degrees to horizontal. Flowers with diurnal anthesis, partially resupinate; perianth straight to uniformly curved, white to green to yellow, triangular in cross-section; ovary yellow to red. Fruits blue, glabrous. The six species united here in subgen. Stenochlamys sect. Angustae were formerly distributed across three sections by Andersson (1985 a 1992; sects. Stenochalmys, Tortex [now Taeniostrobus], and Lasia). Section Angustae with 1.0 LPP support as a monophyletic group in the molecular analysis is sister to sect. Stenochlamys.
Species.
* Heliconia angusta Vell.; + H. dasyantha Koch & Bouché; * H. farinosa Raddi; * H. laneana Barreiros; * H. sampaioana L. Emygdio; * H. velloziana L. Emygdio.
Distribution.
Tropical Northern South America (Brazil, French Guiana, Suriname).
description: Published as part of Kress, W. John, Fér, Tomáš & Carlsen, Mónica M., 2025, Phylogenomics and a new classification of the tropical genus Heliconia L. (Monocots, Zingiberales, Heliconiaceae), pp. 37-66 in PhytoKeys 251 on pages 37-66, DOI: 10.3897/phytokeys.251.130409
Self-assembly of Co/Pt stripes with current-induced domain wall motion towards 3D racetrack devices
Creators: name: Fedorov, Pavel
name: Soldatov, Ivan
name: Neu, Volker
name: Schäfer, Rudolf
name: Schmidt, Oliver G.
name: Karnaushenko, Daniil
Publisher: name: [London] : Nature Publishing Group UK
Year: 2024
Subjects: subject: glass
subject: hydrogel
subject: nanomaterial
subject: nanowire
subject: polyimide
subject: polymer
subject: self assembled monolayer
subject: curvature
subject: magnetic property
subject: memory
subject: three-dimensional modeling
subject: torque
subject: acceleration
subject: anisotropy
subject: Article
subject: calibration
subject: chirality
subject: coercivity
subject: cooling
subject: current amplitude
subject: current density
subject: diffusion
subject: electric current
subject: finite element analysis
subject: geometry
subject: heating
subject: hysteresis
subject: layer by layer deposition
subject: light
subject: magnetron sputtering
subject: motion
subject: orbit
subject: polymerization
subject: power supply
subject: radial diffusivity
subject: spin coating
subject: spin orbit torque
subject: stereolithography
subject: surface property
subject: temperature measurement
subject: tensile strength
subject: tensiometry
subject: thermal conductivity
subject: thermostability
subject: thickness
subject: three dimensional computer aided design
subject: velocity
subject: waveform
subject: article
subject: controlled study
subject: human
subject: 500

description: Modification of the magnetic properties under the induced strain and curvature is a promising avenue to build three-dimensional magnetic devices, based on the domain wall motion. So far, most of the studies with 3D magnetic structures were performed in the helixes and nanowires, mainly with stationary domain walls. In this study, we demonstrate the impact of 3D geometry, strain and curvature on the current-induced domain wall motion and spin-orbital torque efficiency in the heterostructure, realized via a self-assembly rolling technique on a polymeric platform. We introduce a complete 3D memory unit with write, read and store functionality, all based on the field-free domain wall motion. Additionally, we conducted a comparative analysis between 2D and 3D structures, particularly addressing the influence of heat during the electric current pulse sequences. Finally, we demonstrated a remarkable increase of 30% in spin-torque efficiency in 3D configuration.
Desisa (Cylindrostyrax) marmorata Breuning 1938
Creators: name: Gupta, Rajeev
name: Vitali, Francesco
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy

description: 1. Desisa (Cylindrostyrax) marmorata Breuning, 1938 Desisa marmorata Breuning, 1938c: 374.
Type Locality: India: Andaman I., Port Blair (HT ♂); BMNH. Desisa (Cylindrothorax) marmorata Breuning, 1961b: 262 (Cat., m. s.). Distribution: India (Andaman I.: Port Blair).
description: Published as part of Gupta, Rajeev & Vitali, Francesco, 2017, The checklist of longhorn beetles (Coleoptera: Cerambycidae) from India, pp. 1-317 in Zootaxa 4345 (1) on page 189, DOI: 10.11646/zootaxa.4345.1.1, http://zenodo.org/record/1044137
Additional file 1: Figure S1. of Synthesis, Characterization, Luminescent and Nonlinear Optical Responses of Nanosized ZnO
Creators: name: Multian, Volodymyr
name: Uklein, Andrii
name: Zaderko, Alexander
name: Kozhanov, Vadim
name: Boldyrieva, Olga
name: Linnik, Rostyslav
name: Lisnyak, Vladyslav
name: Gayvoronsky, Volodymyr
Publisher: name: Figshare
Year: 2017
Subjects: subject: Biochemistry
subject: Space Science
subject: Medicine
subject: Molecular Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Marine Biology
subject: Hematology
subject: Infectious Diseases
subject: FOS: Health sciences

description: A typical color change of EtOH (a–c) and (d–e) i-PrOH solutions of Zn(CH3COO)2 × 2H2O, at different stages of the interaction of components: (a) starting solution 1–2 min after the preparation, (b) 30 min, and (c) 1-h heating at 60 °C; (d) 20 min after the preparation, (e) 60 min, and (f) 2-h heating at 60 °C. Figure S2. The starting i-PrOH solution of Zn(CH3COO)2 × 2H2O (a) and (b–c) luminescence of ZnO NP obtained by hydrolysis. Figure S3 a, b. Comparison of UV-Vis spectra of ZnO NP in solutions and solid precipitates. Figure S4. UV-Vis spectra of ZnO NP in the resulted solutions (a) EtOH, (b) i-PrOH, (c) MeCN, and (d) PPG. (PDF 346 kb)
Euthymia regalis Jousseaume 1884
Creators: name: Albano, Paolo G.
name: Franco, Davide Di
name: Azzarone, Michele
name: J., Piet A.
name: Bakker
name: Sabelli, Bruno
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Ptenoglossa
Triphoridae
Euthymia
Euthymia regalis

description: Euthymia regalis Jousseaume, 1884 (Fig. 62)
Euthymia regalis Jousseaume, 1884: 265, pl. 4, fig. 18.
TYPE LOCALITY. — New Caledonia.
TYPE MATERIAL. — Syntype. New Caledonia • MNHN-IM-2000-1133; 1 specimen; from type locality.
ORIGINAL DESCRIPTION. — Testa solida, alba, quandoque rarius rufo-maculata, elongato-turrita, subcylindrica, apice breviter et parum attenuata; spiraliter costata et striata; apice truncato; anfractibus persistentibus 12, convexiusculis, lente crescentibus, sutura vix impressa separatis; ultimo carinato, infra planulato, costis quinque filiformibus cincto; apertura subrotundata, ad suturam emarginata; canali brevi, recurvo. — Long. 11, lat. 4 millim.
[Latin diagnosis followed by a discussion in French]
TRANSLATION OF THE LATIN TEXT. — Solid shell, sometimes with sparse red spots, turreted-elongated, subcylindrical, short and slightly slender apex; spirally ribbed and striated; truncated apex; whorls are always 12, slightly convex, slowly growing, separated by a slightly impressed suture; carinated last whorl, flattened below, with five filiform spiral cords; roundish aperture, bordered with the suture; short and curved siphon. — Length 11, diameter 4 mm.
DIAGNOSIS. — Shell cyrtoconoid with flat sides. Syntype 10.0 mm high. Teleoconch of c. 10 whorls. Three spiral cords present of which the first one weaker and the third more prominent. Spiral cords with very elongated tubercles at the intersection with rather orthocline axial ribs. A fine spiral thread present suprasuturally. Spiral microsculpture of fine threads. Peristome with additional cords below the first and second spiral cord, but not sufficiently complete in the syntype to judge the extent of the posterior sinus. Base with two additional cords of which the first weakly tubercled and the second smooth. Teleoconch white.
description: Published as part of Albano, Paolo G., Franco, Davide Di, Azzarone, Michele, J., Piet A., Bakker & Sabelli, Bruno, 2023, Review of the types of Indo-Pacific Triphoridae (Mollusca, Gastropoda) in the Muséum national d'Histoire naturelle, Paris, pp. 13-106 in Zoosystema 45 (2) on pages 91-93, DOI: 10.5252/zoosystema2023v45a2, http://zenodo.org/record/7569742
Tunable positions of Weyl nodes via magnetism and pressure in the ferromagnetic Weyl semimetal CeAlSi
Creators: name: Cheng, Erjian
name: Yan, Limin
name: Shi, Xianbiao
name: Lou, Rui
name: Fedorov, Alexander
name: Behnami, Mahdi
name: Yuan, Jian
name: Yang, Pengtao
name: Wang, Bosen
name: Cheng, Jin-Guang
name: Xu, Yuanji
name: Xu, Yang
name: Xia, Wei
name: Pavlovskii, Nikolai
name: Peets, Darren C.
name: Zhao, Weiwei
name: Wan, Yimin
name: Burkhardt, Ulrich
name: Guo, Yanfeng
name: Li, Shiyan
name: Felser, Claudia
name: Yang, Wenge
name: Büchner, Bernd
Publisher: name: [London] : Nature Publishing Group UK
Year: 2024
Subjects: subject: electron
subject: geomagnetism
subject: phase transition
subject: pressure
subject: symmetry
subject: topology
subject: angle resolved photoemission spectroscopy
subject: article
subject: chirality
subject: controlled study
subject: electric potential
subject: magnetism
subject: nonhuman
subject: adult
subject: 500

description: The noncentrosymmetric ferromagnetic Weyl semimetal CeAlSi with simultaneous space-inversion and time-reversal symmetry breaking provides a unique platform for exploring novel topological states. Here, by employing multiple experimental techniques, we demonstrate that ferromagnetism and pressure can serve as efficient parameters to tune the positions of Weyl nodes in CeAlSi. At ambient pressure, a magnetism-facilitated anomalous Hall/Nernst effect (AHE/ANE) is uncovered. Angle-resolved photoemission spectroscopy (ARPES) measurements demonstrated that the Weyl nodes with opposite chirality are moving away from each other upon entering the ferromagnetic phase. Under pressure, by tracing the pressure evolution of AHE and band structure, we demonstrate that pressure could also serve as a pivotal knob to tune the positions of Weyl nodes. Moreover, multiple pressure-induced phase transitions are also revealed. These findings indicate that CeAlSi provides a unique and tunable platform for exploring exotic topological physics and electron correlations, as well as catering to potential applications, such as spintronics.
The impact of chemical short-range order on the thermophysical properties of medium- and high-entropy alloys
Creators: name: Andreoli, Angelo F.
name: Fantin, Andrea
name: Kasatikov, Sergey
name: Bacurau, Vinícius P.
name: Widom, Michael
name: Gargarella, Piter
name: Mazzer, Eric M.
name: Woodcock, Thomas G.
name: Nielsch, Kornelius
name: Coury, Francisco G.
Publisher: name: Amsterdam [u.a.] : Elsevier Science
Year: 2024
Subjects: subject: Chemical short-range order
subject: Differential scanning calorimetry
subject: Dilatometry
subject: High-entropy alloys
subject: Order-disorder effects
subject: 600
subject: 690

description: The unusual behavior observed in the coefficient of thermal expansion and specific heat capacity of CrFeNi, CoCrNi, and CoCrFeNi medium/high-entropy alloys is commonly referred to as the K-state effect. It is shown to be independent of the Curie temperature, as demonstrated by temperature-dependent magnetic moment measurements. CoCrFeNi alloy is chosen for detailed characterization; potential reasons for the K-state effect such as texture, recrystallization, and second-phase precipitation are ruled out. An examination of the electronic structure indicates the formation of a pseudo-gap in the Density of States, which suggests a specific chemical interaction between Ni and Cr atoms upon alloying. Hybrid Monte Carlo/Molecular Dynamic (MC/MD) simulations indicate the presence of non-negligible chemical short-range order (CSRO). Local lattice distortions are shown to be negligible, although deviations around Cr and Ni elements from those expected in a fully disordered structure are experimentally observed by X-ray absorption spectroscopy. The determined bonding distances are in good agreement with MC/MD calculations. A mechanism is proposed to explain the anomalies and calorimetric experiments and their results are used to validate the mechanism.
Heliconia (Taeniostrobus) Griggs
Creators: name: Kress, W. John
name: Fér, Tomáš
name: Carlsen, Mónica M.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Zingiberales
Heliconiaceae
Heliconia

description: 1.3.Heliconia subgenus Taeniostrobus(Kuntze) Griggs, Bull. Torrey Bot. Club 30: 643. 1903.
Figs 3 I – L
Bihai section Taeniostrobus Kuntze, Revisio Generum Plantarum. Pars I: 684. 1891.
Type.
Bihai imbricata Kuntze (Heliconia imbricata (Kuntze) Baker (designated by L. Andersson, Flora of Ecuador 22: 11. 1985.).
Description and taxonomic notes.
Small- to large-sized rhizomatous herbs with Musa -, Canna -, or Zingiber - like habit. Inflorescence erect (rarely pendent), with peduncle, rachis and cincinnal bracts of various colors from pink to red to orange to yellow; cincinnal bracts distichous or spirally arranged. Flowers with diurnal anthesis, not resupinate and fully or partially enclosed in bracts or fully resupinate and held at right angles to bracts; perianth uniformly curved (rarely s-shaped), white to green to yellow; ovary green to yellow to red. Fruits blue, glabrous. subgenus Taeniostrobus in the current classification is made up of two sections (sects. Taeniostrobus and Aurantiacae) and includes species from four earlier designated subgenera (subgens. Taeniostrobus, Heliconia, Stenochlamys, and Griggsia), although the majority of species were included in Andersson’s subgen. Heliconia sect. Tortex. Few, if any, morphological traits are shared by all species across subgen. Taeniostrobus. The very high strong support (LPP = 1.0) in the phylogenomic analysis is primary evidence for uniting these species into a single monophyletic subgenus with two somewhat distinct sections.
Distribution.
Tropical Mexico, Central, and South America (Belize, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Honduras, Mexico, Nicaragua, Panama, Peru, Suriname, Venezuela).
description: Published as part of Kress, W. John, Fér, Tomáš & Carlsen, Mónica M., 2025, Phylogenomics and a new classification of the tropical genus Heliconia L. (Monocots, Zingiberales, Heliconiaceae), pp. 37-66 in PhytoKeys 251 on pages 37-66, DOI: 10.3897/phytokeys.251.130409
Flexible Piezoresistive Polystyrene Composite Sensors Filled with Hollow 3D Graphitic Shells
Creators: name: Guzenko, Nataliia
name: Godzierz, Marcin
name: Kurtyka, Klaudia
name: Hercog, Anna
name: Nocoń-Szmajda, Klaudia
name: Gawron, Anna
name: Szeluga, Urszula
name: Trzebicka, Barbara
name: Yang, Ruizhi
name: Rümmeli, Mark H.
Publisher: name: Basel : MDPI
Year: 2023
Subjects: subject: 3D graphitic shells
subject: conductive polymer composite
subject: multi-walled carbon nanotubes
subject: piezoresistive sensors
subject: 540

description: The objective of this research was to develop highly effective conductive polymer composite (CPC) materials for flexible piezoresistive sensors, utilizing hollow three-dimensional graphitic shells as a highly conductive particulate component. Polystyrene (PS), a cost-effective and robust polymer widely used in various applications such as household appliances, electronics, automotive parts, packaging, and thermal insulation materials, was chosen as the polymer matrix. The hollow spherical three-dimensional graphitic shells (GS) were synthesized through chemical vapor deposition (CVD) with magnesium oxide (MgO) nanoparticles serving as a support, which was removed post-synthesis and employed as the conductive filler. Commercial multi-walled carbon nanotubes (CNTs) were used as a reference one-dimensional graphene material. The main focus of this study was to investigate the impact of the GS on the piezoresistive response of carbon/polymer composite thin films. The distribution and arrangement of GS and CNTs in the polymer matrix were analyzed using techniques such as X-ray diffraction and scanning electron microscopy, while the electrical, thermal, and mechanical properties of the composites were also evaluated. The results revealed that the PS composite films filled with GS exhibited a more pronounced piezoresistive response as compared to the CNT-based composites, despite their lower mechanical and thermal performance.
Pseudodrobna Winkler 2017
Creators: name: Audo, Denis
name: Winkler, Norbert
name: Charbonnier, Sylvain
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Penaeidae
Pseudodrobna

description: Genus Pseudodrobna Winkler, 2017
TYPE SPECIES. — Pseudodrobna kenngotti Winkler, 2017, by monotypy.
INCLUDED SPECIES. — Pseudodrobna kenngotti, Pseudodrobna natator (Glaessner, 1945) n. comb.
description: Published as part of Audo, Denis, Winkler, Norbert & Charbonnier, Sylvain, 2021, Pseudodrobna natator n. comb., a new link between crustacean faunas from the Jurassic of Germany and Cretaceous of Lebanon, pp. 209-218 in Geodiversitas 43 (8) on page 210, DOI: 10.5252/geodiversitas2021v43a8, http://zenodo.org/record/4701081
Desisa (Cylindrostyrax) quadriplagiata Breuning 1938
Creators: name: Gupta, Rajeev
name: Vitali, Francesco
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy

description: 2. Desisa (Cylindrostyrax) quadriplagiata Breuning, 1938
Desisa quadriplagiata Breuning, 1938c: 372; Weigel, 2006: 504 (Distr.).
Type Locality: India: Uttarakhand: Chakata Range, Haldwani (HT ♀); BMNH. Desisa (Cylindrothorax) quadriplagiata Breuning, 1961b: 262 (Cat., m. s.); Löbl & Smetana, 2010: 314 (Cat.). Distribution: India (N-India; Uttarakhand), Nepal & Pakistan.
description: Published as part of Gupta, Rajeev & Vitali, Francesco, 2017, The checklist of longhorn beetles (Coleoptera: Cerambycidae) from India, pp. 1-317 in Zootaxa 4345 (1) on page 189, DOI: 10.11646/zootaxa.4345.1.1, http://zenodo.org/record/1044137
Solving the puzzle of hierarchical martensitic microstructures in NiTi by (111)-oriented epitaxial films
Creators: name: Lünser, Klara
name: Undisz, Andreas
name: Wagner, Martin F.-X.
name: Nielsch, Kornelius
name: Fähler, Sebastian
Publisher: name: Amsterdam : Elsevier
Year: 2023
Subjects: subject: Epitaxial films
subject: Martensitic microstructure
subject: NiTi
subject: Shape memory materials
subject: 600

description: The martensitic microstructure decides on the functional properties of shape memory alloys. However, for the most commonly used alloy, NiTi, it is still unclear how its microstructure is built up because the analysis is hampered by grain boundaries of polycrystalline samples. Here, we eliminate grain boundaries by using epitaxially grown films in (111)B2 orientation. By combining scale-bridging microscopy with integral inverse pole figures, we solve the puzzle of the hierarchical martensitic microstructure. We identify two martensite clusters as building blocks and three kinds of twin boundaries. Nesting them at different length scales explains why habit plane variants with ⟨011⟩B19' twin boundaries and {942} habit planes are dominant; but also some incompatible interfaces occur. Though the observed hierarchical microstructure agrees with the phenomenological theory of martensite, the transformation path decides which microstructure forms. The combination of local and global measurements with theory allows solving the scale bridging 3D puzzle of the martensitic microstructure in NiTi exemplarily for epitaxial films.
NaRuO2: Kitaev-Heisenberg exchange in triangular-lattice setting
Creators: name: Bhattacharyya, Pritam
name: Bogdanov, Nikolay A.
name: Nishimoto, Satoshi
name: Wilson, Stephen D.
name: Hozoi, Liviu
Publisher: name: [London] : Nature Publishing Group
Year: 2023
Subjects: subject: configuration-interaction
subject: crystal fields
subject: 530

description: Kitaev exchange, a new paradigm in quantum magnetism research, occurs for 90° metal-ligand-metal links, t2g5 transition ions, and sizable spin-orbit coupling. It is being studied in honeycomb compounds but also on triangular lattices. While for the former it is known by now that the Kitaev intersite couplings are ferromagnetic, for the latter the situation is unclear. Here we pin down the exchange mechanisms and determine the effective coupling constants in the t2g5 triangular-lattice material NaRuO2, recently found to host a quantum spin liquid ground state. We show that, compared to honeycomb compounds, the characteristic triangular-lattice cation surroundings dramatically affect exchange paths and effective coupling parameters, changing the Kitaev interactions to antiferromagnetic. Quantum chemical analysis combined with subsequent effective spin model simulations provide perspective onto the nature of the experimentally observed quantum spin liquid—it seemingly implies fairly large antiferromagnetic second-neighbor isotropic exchange, and the atypical proximity to ferromagnetic order is related to ferromagnetic nearest-neighbor Heisenberg coupling.
Desisa (Cylindrostyrax) uniformis Breuning 1938
Creators: name: Gupta, Rajeev
name: Vitali, Francesco
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy

description: 3. Desisa (Cylindrostyrax) uniformis Breuning, 1938
Desisa uniformis Breuning, 1938c: 58.
Type Locality: India: Chakata Range, Haldwani (HT ♂); FRI. Desisa (Cylindrothorax) uniformis Breuning, 1961b: 262 (Cat., m. s.). Distribution: India (Uttarahkand: Chakata Range, Haldwani, N-India).
Egesina Pascoe, 1864a: 49 (type sp.: Egesina rigida Pascoe, 1864); Cuphisia Pascoe, 1866b: 229 (type sp.: Cuphisia callosa Pascoe); Callienispia Fisher, 1925: 210 (type sp.: Callienispia elegans Fisher); Platyzeargyra Fisher, 1925: 213 (type sp.: Platyzeagyra bakeri Fisher); Neoegesina Fisher, 1925: 215 (type sp.: Neoegesina ornata Fisher, 1925); Niijimaia Matsushita, 1933: 386 (type sp.: Niijimaia bifasciana Matsushita); Pseudenispia Breuning, 1938c: 388 (type sp.: Egesina picta Breuning); Larica Breuning, 1938c: 388 (type sp.: Egesina cleroides Breuning); Callegesina Breuning, 1943c: 34 (type sp.: Egesina vitticollis Breuning).
description: Published as part of Gupta, Rajeev & Vitali, Francesco, 2017, The checklist of longhorn beetles (Coleoptera: Cerambycidae) from India, pp. 1-317 in Zootaxa 4345 (1) on page 190, DOI: 10.11646/zootaxa.4345.1.1, http://zenodo.org/record/1044137
Inella rossiteri Jousseaume 1884
Creators: name: Albano, Paolo G.
name: Franco, Davide Di
name: Azzarone, Michele
name: J., Piet A.
name: Bakker
name: Sabelli, Bruno
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Ptenoglossa
Triphoridae
Inella
Inella rossiteri

description: Inella rossiteri Jousseaume, 1884
(Fig. 63)
Inella rossiteri Jousseaume, 1884: 249, pl. 4, fig. 9.
TYPE LOCALITY. — New Caledonia.
TYPE MATERIAL. — Lectotype. New Caledonia • MNHN-IM-2000-29272; here designated.
Paralectotypes. New Caledonia • MNHN-IM-2000-1246; 1 specimen; from type locality • Triphoridae indet.: MNHN-IM-2000-1313; 1 specimen.
ORIGINAL DESCRIPTION. — Testa cylindrico-conica, ventrosula, rufolutescente; anfractibus 14 planis, sutura profunda, canaliculata, discretis; tuberculis albescentibus, contiguis et oppositis, in seriebus quatuor dispositis, muricatis; ultimo ad basin depresso, carinis octonis, moniliferis ornato; apertura subrotundata, lateraliter fissa, canali brevi, aperto, munita. — Long. 5-6, lat. 1,5-1,7 millim.
[Latin diagnosis followed by a discussion in French]
TRANSLATION OF THE LATIN TEXT. — Cylindrical-conical shell, quite swollen, red-yellowish; 14 flattened whorls, separated by a deep canaliculated suture; tubercles are whitish, contiguous and opposing, arranged in four series, pointed; the last whorl is depressed at the base, adorned by eight granular spiral cords; roundish aperture, laterally fissured, with a short and open siphon. — Length 5-6, diameter 1.5-1.7 mm.
DIAGNOSIS. — Shell cyrtoconoid. Lectotype 5.2 mm high, paralectotype 5.9 mm high. Teleoconch of 8 whorls. Four spiral cords present, the third appearing on the third whorl, while the second on the sixth. First and fourth cords with tubercles at the intersection with rather prosocline axial ribs. Second and third cord initially with thin tubercles, becoming larger towards the last whorl. A smooth thread present suprasuturally. Peristome without additional spiral cords. Posterior sinus shallow. Base with four additional rather smooth spiral cords. Multispiral protoconch of c. 4 whorls with one spiral keel and axial riblets. First four teleoconch whorls light brown, then teleoconch progressively lighter. Protoconch light brown.
REMARKS. — The type series contained two lots. Lot MNHN-IM-2000-1313 contained a single triphorid fragment (Fig. 62R) which can be easily recognized not to belong to Inella rossiteri due to the presence of only three tubercled spiral cords instead of four, a very specific character of I. rossiteri, rarely found among the Triphoridae.
description: Published as part of Albano, Paolo G., Franco, Davide Di, Azzarone, Michele, J., Piet A., Bakker & Sabelli, Bruno, 2023, Review of the types of Indo-Pacific Triphoridae (Mollusca, Gastropoda) in the Muséum national d'Histoire naturelle, Paris, pp. 13-106 in Zoosystema 45 (2) on page 94, DOI: 10.5252/zoosystema2023v45a2, http://zenodo.org/record/7569742
Heliconia (sect. Aurantiacae) W. J. Kress 2025, sect. nov.
Creators: name: Kress, W. John
name: Fér, Tomáš
name: Carlsen, Mónica M.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Zingiberales
Heliconiaceae
Heliconia

description: 1.3. 2.Heliconia section AurantiacaeW. J. Kress,sect. nov.
Figs 3 K, L
Type.
Heliconia aurantiaca Ghiesbr. ex Lemaire.
Description and taxonomic notes.
Small- to medium-sized rhizomatous herbs with Musa - to Zingiber - like habit. Inflorescence erect, with peduncle, rachis and cincinnal bracts red to orange; cincinnal bracts spirally arranged (rarely distichous). Flowers with diurnal anthesis, fully resupinate and held at right angles to bracts; perianth uniformly curved, green to yellow; ovary green to yellow. Fruits blue, glabrous. The five species united here in subgen. Taeniostrobus sect. Aurantiacae were formerly placed in two sections by Andersson (1992; sects. Lanea and Zingiberastrum [now Longiflorae]). The species in this section, with primarily spirally arranged bracts, resupinate flowers, and some with Zingiber - like leaf arrangement, are distinct from taxa in sect. Taeniostrobus and are supported in the molecular analysis with 0.92 LPP support as a monophyletic group sister to that section.
Species.
* Heliconia adflexa (Griggs) Standl.; * H. aurantiaca Ghiesbr. ex Lemaire; * H. crassa Griggs; * H. schiedeana Kl.; * H. spissa Griggs.
Distribution.
Tropical Mexico and Central America (Belize, Costa Rica, Guatemala, Honduras, Mexico, Nicaragua).
description: Published as part of Kress, W. John, Fér, Tomáš & Carlsen, Mónica M., 2025, Phylogenomics and a new classification of the tropical genus Heliconia L. (Monocots, Zingiberales, Heliconiaceae), pp. 37-66 in PhytoKeys 251 on pages 37-66, DOI: 10.3897/phytokeys.251.130409
Correlation induced magnetic topological phases in the mixed-valence compound SmB6
Creators: name: Liu, Huimei
name: Hirschmann, Moritz M.
name: Sawatzky, George A.
name: Khaliullin, Giniyat
name: Schnyder, Andreas P.
Publisher: name: College Park, MD : APS
Year: 2023
Subjects: subject: Antiferromagnetism
subject: Boron compounds
subject: Magnetic susceptibility
subject: Neutron scattering
subject: Samarium compounds
subject: Collective modes
subject: Electron bands
subject: F-electrons
subject: First-order phase transitions
subject: Magnetic correlation
subject: Mixed valence compounds
subject: Neutron scattering experiments
subject: Nodal line
subject: Spin susceptibility
subject: Topological phase
subject: Topology
subject: 530

description: SmB6 is a mixed-valence compound with flat f-electron bands that have a propensity to magnetism. Here, using a realistic Γ8 quartet model, we investigate the dynamical spin susceptibility and describe the in-gap collective mode observed in neutron scattering experiments. We show that as the Sm valence increases with pressure, the magnetic correlations enhance and SmB6 undergoes a first-order phase transition into a metallic antiferromagnetic state, whose symmetry depends on the model parameters. The magnetic orderings give rise to distinct band topologies: while the A-type order leads to an overlap between valence and conduction bands in the form of Dirac nodal lines, the G-type order has a negative indirect gap with weak Z2 indices. We also consider the spin polarized phase under a strong magnetic field, and find that it exhibits Weyl points as well as nodal lines close to the Fermi level. The magnetic phases show markedly different surface states and tunable bulk transport properties, with important implications for experiments. Our theory predicts that a magnetic order can be stabilized also by lifting the Γ8 cubic symmetry, thus explaining the surface magnetism reported in SmB6.
A multifunctional highway system incorporating superconductor levitated vehicles and liquefied hydrogen
Creators: name: Vakaliuk, O.
name: Song, Shaowei
name: Floegel-Delor, U.
name: Werfel, F.
name: Nielsch, Kornelius
name: Ren, Zhifeng
Publisher: name: Melville, NY : AIP Publishing
Year: 2023
Subjects: subject: 600
subject: 621.3

description: Magnetic levitation for the transport of people and goods using bulk superconductors and electrical power transmission using superconductors have both been demonstrated, but neither has been developed for daily use due to technological deficiencies and high costs. We envision combining the transport of people and goods and energy transmission and storage in a single system. Such a system, built on existing highway infrastructure, incorporates a superconductor guideway, allowing for simultaneous levitation of vehicles with magnetized undercarriages for rapid transport without schedule limitations and lossless transmission and storage of electricity. Incorporating liquefied hydrogen additionally allows for simultaneous cooling of the superconductor guideway and sustainable energy transport and storage. Here, we report the successful demonstration of the primary technical prerequisite, levitating a magnet above a superconductor guideway.
Coulomb exchange as source of Kitaev and off-diagonal symmetric anisotropic couplings
Creators: name: Bhattacharyya, Pritam
name: Petersen, Thorben
name: Bogdanov, Nikolay A.
name: Hozoi, Liviu
Publisher: name: London : Springer Nature
Year: 2024
Subjects: subject: correlated molecular calculations
subject: gaussian-basis sets
subject: configuration-interaction
subject: crystal fields
subject: spin-orbit
subject: cluster
subject: liquid
subject: 530

description: Exchange underpins the magnetic properties of quantum matter. In its most basic form, it occurs through the interplay of Pauli’s exclusion principle and Coulomb repulsion, being referred to as Coulomb or direct exchange. Pauli’s exclusion principle combined with inter-atomic electron hopping additionally leads to kinetic exchange and superexchange. Here we disentangle the different exchange channels in anisotropic Kitaev–Heisenberg context. By quantum chemical computations, we show that anisotropic Coulomb exchange, completely neglected so far in the field, may be as large as (or even larger than) other contributions — kinetic exchange and superexchange. This opens new perspectives onto anisotropic exchange mechanisms and sets the proper conceptual framework for further research on tuning Kitaev–Heisenberg magnetism.
Heliconia (Colubrosae) W. J. Kress, subgen. nov.
Creators: name: Kress, W. John
name: Fér, Tomáš
name: Carlsen, Mónica M.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Zingiberales
Heliconiaceae
Heliconia

description: 1.4.Heliconia subgenus ColubrosaeW. J. Kress,subgen. nov.
Figs 4 A – D
Type.
Heliconia dielsiana Loes.
Description and taxonomic notes.
Medium- to large-sized rhizomatous herbs with Musa - like habit. Inflorescence pendent or erect, with peduncle, rachis, and cincinnal bracts usually entirely red, sometimes green distally (rarely yellow); cincinnal bracts distichous or spirally arranged, horizontal or reflexed, usually elongate and tapering. Flowers with diurnal anthesis, fully or partially enclosed in bracts or resupinate and held at right angles to bracts; perianth s-shaped (sigmoid) or c-shaped (sharply curved), free sepal extended or not and reflexed, fused sepals reflexed at tips or not, generally yellow, sometimes white to green; ovary yellow to white (rarely green). Fruits blue, glabrous. The numerous species placed here in subgen. Colubrosae were formerly included in either subgen. Griggsia (with pendent inflorescences) or subgen. Stenochlamys (with erect inflorescences) by both Andersson (1985 a, 1992) and Kress et al. (1999), but these two subgenera were never closely associated. The 1.0 LPP support in the molecular analysis strongly unites the species in these two subgenera into a single monophyletic lineage.
Distribution.
Tropical Central and South America (Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guyana, Panama, Peru, Venezuela).
description: Published as part of Kress, W. John, Fér, Tomáš & Carlsen, Mónica M., 2025, Phylogenomics and a new classification of the tropical genus Heliconia L. (Monocots, Zingiberales, Heliconiaceae), pp. 37-66 in PhytoKeys 251 on pages 37-66, DOI: 10.3897/phytokeys.251.130409
Egesina fuchsi Breuning 1970
Creators: name: Gupta, Rajeev
name: Vitali, Francesco
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy

description: 1. Egesina fuchsi Breuning, 1970
Egesina (s.s.) fuchsi Breuning, 1970a: 11.
Type Locality: India: TN, Coimbatore, Anamalai Hills, Cinchosa (HT); Collection Herbert Schmid, Wien. Distribution: India (TN, Coimbatore, Anamalai Hills, Cinchosa).
description: Published as part of Gupta, Rajeev & Vitali, Francesco, 2017, The checklist of longhorn beetles (Coleoptera: Cerambycidae) from India, pp. 1-317 in Zootaxa 4345 (1) on page 190, DOI: 10.11646/zootaxa.4345.1.1, http://zenodo.org/record/1044137
MPEC 2024-X12 : 2024 WK15
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2024 WK15

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.