bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population-based neuroimaging reveals traces of childbirth in the maternal brain
Authors: de Lange Ann-Marie G. , Kaufmann Tobias , van der Meer Dennis , Maglanoc Luigi A. , Alnæs Dag , Moberget Torgeir , Douaud Gwenaëlle , Andreassen Ole A. , Westlye Lars T. 
Published: October 2019

Significance
Pregnancy is one of the most dynamic periods in a woman’s life, involving a remarkable potential for brain plasticity that promotes cognitive and emotional adjustments to the newborn. We provide evidence for a relationship between number of childbirths and brain aging in 12,021 middle-aged women, suggesting that potential parity-related brain changes may endure beyond the postpartum period and influence the course of neurobiological aging.
Synergistic boost of output power density and efficiency in In-Li–codoped SnTe
Authors: Guo Fengkai , Wu Haijun , Zhu Jianbo , Yao Honghao , Zhang Yang , Cui Bo , Zhang Qian , Yu Bo , Pennycook Stephen J. , Cai Wei , Chu Ching-Wu , Sui Jiehe 
Published: October 2019

Significance
In the search for high-performance thermoelectric materials, in addition to conversion efficiency, output power density is also an important consideration for practical applications in generating electrical energy from solar or waste heat. We designed and fabricated an SnTe-based material that exhibits both high conversion efficiency and high output power density by indium and lithium codoping. Indium doping realizes the resonant state in the compound, while lithium doping further increases its carrier concentration by acting as an acceptor as well as dramatically reducing its lattice thermal conductivity by forming disperse precipitates. This work provides an example for finding high-performance thermoelectric materials that are suitable for practical application and provides guidance for future research.
PRC2 engages a bivalent H3K27M-H3K27me3 dinucleosome inhibitor
Authors: Diehl Katharine L. , Ge Eva J. , Weinberg Daniel N. , Jani Krupa S. , Allis C. David , Muir Tom W. 
Published: October 2019

Significance
A subset of deadly pediatric brain tumors called diffuse intrinsic pontine gliomas express a mutant histone H3 with a lysine-to-methionine substitution at position 27 (H3K27M), which has been shown to drive tumorigenesis in these cancers. While there is evidence that H3K27M inhibits the H3K27 methyltransferase known as polycomb repressive complex 2 (PRC2), the precise mechanisms by which H3K27M acts remain a matter of debate. In this work, we used biochemical and in cell assays to characterize the dependence of PRC2 binding to H3K27M on other PRC2 ligands, including H3K27me3. We synthesized designer chromatin inhibitors containing H3K27M and H3K27me3 nucleosomes and found that PRC2 is inhibited by a dinucleosome, suggesting that PRC2 is sequestered on chromatin by these bivalent inhibitors.
Tunable corrugated patterns in an active nematic sheet
Authors: Senoussi Anis , Kashida Shunnichi , Voituriez Raphael , Galas Jean-Christophe , Maitra Ananyo , Estevez-Torres André 
Published: October 2019

SignificanceTo what extent can we engineer matter that shapes itself? To investigate this question we study an aqueous solution containing molecular motors that walk on protein filaments. When the filaments are long and attract each other, bundles of filaments are parallelly oriented. We show that such a nematic solution in the presence of multimers of motors has an unexpected behavior: It forms a fluid film that autonomously wrinkles. The observed wrinkles have a well-defined wavelength that decreases with increasing motor concentration. The wrinkles either are stable or break into a chaotic flowing state at high motor concentration, providing insights into how to engineer static or dynamic materials with this class of active matter.
Superconductivity in Weyl Semimetal NbP: Bulk vs. Surface
Authors: Baenitz M , Schmidt M , Suess V , Felser C , Lüders K 
Published: October 2019

Abstract
Transition metal monopnictides belong to the new class of semimetals where the bulk properties are determined by the presence of pairs of nodes with different chirality formed by linear dispersive states in the k-space. Beside the anomaly in the bulk magnetotransport superconductivity is frequently found in some Weyl semimetals. We found signatures of superconductivity in ac and dc magnetization measurements of highly pure and stoichiometric NbP powder. We determined the lower and upper critical field and the Ginzburg-Landau parameter. The relative small superconducting volume fraction is related to either effect of finite grain size and/or surface superconductivity. The last mentioned may originate from either off stoichiometric (Nb-rich) surface layers or a strained surface with different electronic properties. Furthermore the intrinsic normal state susceptibility is determined taking into account a paramagnetic contribution of a few ppm of magnetic impurities.
Effect of non-magnetic rare earth substitution for Zr on mixed anion Zr(P, Se)2 superconductors II
Authors: Iwakiri K , Nishio T , Kawashima K , Ishida S , Oka K , Fujihisa H , Gotoh Y , Hase I , Iyo A , Ogino H , Eisaki H , Yoshida Y , Kitô H 
Published: October 2019

Abstract
In ZrP1.25Se0.75, the superconducting transition temperature T
c is increased from 5.8 K to 7.6 K when Sc atoms are partially substituted for Zr atoms having almost the same atomic radius as Sc atoms. Transport measurements show that holes are doped with substituting Sc atoms. The density of states in (Zr, Sc)P1.25Se0.75 is derived from band structure calculations and its implication in the doping behaviour and the increase of T
c is discussed.
Transmission EBSD (t-EBSD) to determine grain and grain boundary properties on nanostructured superconductor samples
Authors: Koblischka-Veneva A. , Koblischka M. R. , Schmauch J. , Murakami M. 
Published: October 2019

Abstract
The knowledge of the properties of the grains and their grain boundaries is essential for the further optimization of sample performance of various high-T
c samples (YBa2Cu3O
y
(YBCO), Bi-based cuprates, MgB2, iron-based materials). In these materials either the grains are of nanometer dimensions or the various additions of secondary phase(s) to improve the flux pinning are required to be of nanometer dimensions, so a high achievable resolution and better imaging properties are important to obtain reasonably high image quality of the recorded Kikuchi patterns to enable automated orientation mapping using the EBSD technique. Therefore, the newly developed transmission-EBSD (t-EBSD) technique is the method of choice to analyze the grain and the grain boundary properties in such nanostructured superconducting materials. Several results obtained on MgB2, melt-textured, infiltration-growth processed YBCO and electrospun Bi2Sr2CaCu2O8 nanowires are presented.
Optimization of YbBa2Cu3Oy Thick Film Formation on MgO Substrates using Yb2BaO5 and liquid phase
Authors: Hattori A. , Muralidhar M. , Sai Srikanth A. , Murakami M. 
Published: October 2019

Abstract
The production of best thick YbBa2Cu3Oy (Yb123) films on MgO substrates are crucial for the utilization of this technology in silver sheeted wire as similar to Bi-2223. In this work, in order to optimize YbBa2Cu3Oy films on MgO substrates, a mixture of alpha-terpineol and 2-ethyl acetate was utilized as a solvent to which 100 nm sized stoichiometric powder mixture of Yb2BaO5, BaCuO2 and CuO was added and grinded for several hours to form a highly dense paste. Thick film precursors were prepared by spreading the paste over MgO substrates with a screen printing technique and various sintered and quench studies are done. Growth temperature is systematically varied between 800 and 950 °C for 30 minutes in air and quenched in liquid nitrogen. Similarly, sintering durations are varied systematically from 15 minutes to 8 hours. XRD reveals conformed that large Yb123 grains are formed when the thick films are sintered at 825 °C for 1 hour on MgO substrate. SEM micrographs are also in congruence with the XRD results depicting the giant Yb123 crystals. The present results clearly demonstrate that optimization of the growth temperature and time is crucial to obtain the large thick YbBa2Cu3Oy films on MgO substrates.
Effects of vicinal substrates on the orientation of Bi2Sr2CaCu2O8+x thin films when the metal-organic decomposition method is used
Authors: Yamada Y , Okamoto T 
Published: October 2019

Abstract
We have prepared (010) (or (100)) oriented Bi2Sr2CaCu2O8+x
(Bi2212) thin films by metal-organic decomposition (MOD) method which is one kind of solution method. The flat and vicinal (100) substrate (the miscut angle φ = 5° toward the direction [001]) of NdGaO3 (NGO) was used. When using vicinal substrates, the Bi2212 (020) (or (200)) peak appeared clearly in the XRD patterns. From the SEM image, it was found that elongated plate-like crystal grains of Bi2212 were grown. From the viewpoint of lattice matching, this elongated crystal grain is considered to be (010) (or (100)) oriented Bi2212 crystal grains.
Dynamics of a vortex system in a layered high-temperature superconductor under a pulsed current impact
Authors: Rudnev I A , Maksimova A N , Moroz A N , Kashurnikov V A 
Published: October 2019

Abstract
By using the Monte Carlo method, electric field relaxation has been numerically studied in a 2D layered HTS with defects. Time dependences of the electric field strength inside the sample for an instantaneous rise of electric current have been calculated for different temperatures. The influence of temperature on the shape of such dependences has been demonstrated. The impact of a rectangular current pulse on the vortex system has been studied. The value of the response field strength and its dependence on the amplitude and duration of the pulse have been calculated as well as the impact of pulse duration on the shape of the response.
Critical states in two overlapped rectangular superconducting plates
Authors: Ooi Shinsuke , Kato Masaru 
Published: October 2019

Abstract
We study vortex penetration into two-layer structures of superconducting plates under a perpendicular magnetic field. We solve the heat transport equation and the Maxwell equations with the current-voltage relation for superconductor, simultaneously, and obtain magnetic flux and current densities. We show how magnetic flux structure depends on the structure, especially distance of two-layer of superconductors.
Impurity induced insulator-to-metal transitions in half-filled Mott insulators
Authors: Yokoyama Hisatoshi , Sato Ryo , Kobayashi Kenji 
Published: October 2019

Abstract
In view of cuprate superconductors, effects of point-type impurity potential (V) on half-filled antiferromagnetic and paramagnetic states are studied for a strongly correlated square-lattice Hubbard model (U/t = 12) with a diagonal transfer (t′), using a variational Monte Carlo method. In the trial states, we introduce a Rice-Brinkman-type one-body projector for V, which enables us to treat the whole range of V (− ∞ < V/t < ∞) with small statistical errors. Filling-control-type Mott (insulator-to-metal) transitions are found to occur at

V
=

V
U

(
±
)

(∼ ±U). In the metallic states

(

|
V
|

>

|

V
U

(
±
)

|

)

, charge carriers are holes (electrons) in the case of attractive (repulsive) potential. The mechanism of the transitions is intuitively understood.
Antiferromagnetism, superconductivity and phase diagram in the three-band model of high-temperature cuprates
Authors: Yanagisawa Takashi 
Published: October 2019

Abstract
We investigate the ground state of the two-dimensional three-band d-p model for for high-temperature superconductors on the basis of a variational Monte Carlo method. We employ an optimization variational Monte Carlo method that we have developed recently. The many-body wave function is improved beyond the Gutzwiller ansatz by adopting the wave function in the form ψ = exp(−S)ψG
where ψG
represents the Gutzwiller function and S is a kinetic operator. The strong magnetic correlation and also superconductivity (SC) are induced by the on-site Coulomb repulsive interaction. It is important to clarify the phase diagram that includes superconductive phase and antiferromagnetic phase. We show the phase diagram to show the antiferromagnetic region in the parameter space. High-temperature superconductivity may occur in the strongly correlated region near the antiferromagnetic boundary.
Evaluation of superconducting properties for YBa2Cu3Oy coated conductors fabricated by self-heating technique in Pulsed Laser Deposition method
Authors: Sato W. , Tsuchiya Y. , Ichino Y. , Yoshida Y. 
Published: October 2019

Abstract
We fabricated YBa2Cu3O
y
coated conductors with 0.4 - 4.0 μm in the thickness on IBAD-MgO template deposited on Hastelloy metal substrates which were heated by a self-heating (S-H) technique in pulsed laser deposition method. The self-heating (S-H) technique is a method to heat a metal substrate by the Joule heat. In addition, preset substrate temperature (T
s) was gradually changed during the film deposition. It is possible to suppress a-axis grains even in a thick film by the S-H technique. Critical current density (J
c) and critical current (I
c) reached 2.0 MA/cm2 and 800 A/cm-width in a film with the thickness of 4.0 μm at 77 K and self-field.
Development of multi-filamentated long EuBCO coated conductors with BHO doping by plane-plume PLD method
Authors: Ibi A , Machi T , Nakaoka K , Sato M , Izumi T , Higashikawa K , Kiss T 
Published: October 2019

Abstract
Long REBa2Cu3Ox (REBCO, RE: rare earth element) coated conductors with BaMO3 (BMO, M: metal) doping have been expected for the industrial and commercial applications. It is known that critical current (I
c) of REBCO coated conductors (with or without artificial pinning centers doping) in magnetic field at high temperature is superior to the other superconducting wires. Especially, we have found that EuBa2Cu3Ox (EuBCO) coated conductors with BaHfO3 (BHO) doping show higher critical current density (J
c) and I
c at high temperature in self and magnetic fields than those of YBa2Cu3Ox and GdBa2Cu3Ox coated conductors with BHO doping. However, in order to realize EuBCO coated conductors with BHO doping for various applications such as an armature coil, the much higher uniformity of not only longitudinal and but transversal I
c distributions of long REBCO coated conductors with high in-field performance for filamentary structure is required. The plane-plume PLD (pulsed laser deposition) method is performed by shortening the target-substrate distance and increasing the number of plumes with scan of X-Y axes directions to increase the deposition rate and averaging the deposition conditions which should relate to obtain the uniformity I
c distributions. We fabricated the EuBCO coated conductors with BHO doping (of 0.6 m length and 10 mm in width) by the combination of the ion-beam assisted deposition (IBAD) and the plane-plume PLD method and then we processed the multi-filamentary structure EuBCO coated conductors with BHO doping (of 8 filaments of 440 μm, 0.6 m in length and 5 mm in width) by using the excimer laser scribing to reduce the AC loss and to control the shielding current. I
c distributions in a width direction of this EuBCO coated conductor with BHO doping was improved as an uniformity of filament-I
c of 4.3 %.
Recently, we fabricated the 16 filamentary and 3 m long EuBCO coated conductor with BHO doping by IBAD / plane-plume PLD method. We confirmed that the hysteresis loss was reduce to 1/16 by a 16 filamentary EuBCO coated conductor with BHO doping comparing with EuBCO coated conductor with BHO doping without filamentation.
Dependences of AC Loss in Stacked REBa2Cu3Oy Superconducting Tapes on the Interval among Tapes under Perpendicular Magnetic Field
Authors: Sasa H , Kawasaki G , Miura S , Iwakuma I , Izumi T , Machi T , Ibi A 
Published: October 2019

Abstract
In this study, we focused on the dependence of the AC loss in REBa2Cu3O
y
(REBCO, RE = rare earth, Y, Eu, Gd) superconducting tapes stacked perpendicular to the tape face on the interval between the superconducting layers. The AC loss of the 2-layer stacked tapes with various interval in perpendicular field was investigated by pickup-coil method. The AC loss for external applied magnetic field, B
m, below the penetration field, B
p, increases with increasing the interval. In the case that the ratio of the distance between the neighboring superconducting layer, D, to the width of the tape, w, (D/w) is smaller than 0.1, the AC loss of 2-layer tapes decreased to 1/2 of that of 1-layer tape. On the other hand, in the case of D/w being larger than 0.1, the AC loss of 2-layer tapes was larger than 1/2 and it approached the AC loss of 1-layer tape with increasing D/w. From the result obtained in this study, it is predicted that, for B
m below B
p, the AC loss of stacked REBCO tapes with large D/w, such as multifilamentary tapes, is larger than the AC loss of stacked non-scribed REBCO tapes. However, for B
m above B
p: a large AC loss region, it is known that the AC loss of the multifilamentary tapes decreases compared with that of non-scribed tapes. Next step, AC loss of the multifilamentary tapes for B
m below B
p will be investigated experimentally and theoretically.
Fabrication of a Compact High-field Magnet by Coated Conductor Stacks
Authors: Hashimoto T , Pyon S , Iijima Y , Sugiura S , Uji S , Terashima T , Tamegai T 
Published: October 2019

Abstract
A bulk magnet was fabricated by stacking coated conductors with enhanced J
c by introducing nanorods. The fabricated CC stack consists of 100 pieces of CCs, and it was magnetized by field-cooling method in an applied field of 14.5 T down to 4.2 K. By reducing the magnetic field down to zero at a ramp of rate 1 T/min, we have succeeded in trapping 12.6 T at the center of the CC stack. We also confirmed that the CC stack can sustain the high trapped field for more than 20 min, which demonstrates the practical usefulness of such a staked CC magnet.
Study of the superconducting layer microstructure and (Nb,Ti,Ta)3Sn bronze strands properties
Authors: Abdyukhanov I M , Pantsyrny V I , Silaev A G , Tsapleva A S , Konovalova N V , Alekseev M V , Dergunova E A , Mareev K A , Nasibulin M N , Drobyshev V A , Kravtsova M V , Lykianov P A , Krylova M V 
Published: October 2019

Abstract
Superconducting materials with high current carrying capacity operating in magnetic fields up to 18 T at 4.2 K are required for promising applications in magnetic systems of high-energy physics devices, NMR-spectroscopes and others. The paper presents the study results of the Nb3Sn strands manufactured by the bronze route differed in the filament composition. The filaments were made from the alloys Nb-3.5 wt. %Ta and Nb-7.0wt.%Ta and the matrix was produced from the Cu-15.5wt.%Sn-0.25wt.%Ti alloy. To form the superconducting Nb3Sn phase a series of reaction heat treatments of conductor samples were carried out by two-stage regimes with the temperature of the second stage varying from 650 to 720 °C. The microstructure of the Nb3Sn layer was studied by scanning electron microscopy and their electro-physical characteristics were also measured. It was shown that after reaction at 575 °C, 100 h + 650 °C, 200 h samples with different Ta content had almost the same current -carrying capacity in the field range 12-18 T at 4.2 K. The critical temperature of superconductors decreased from 17.5 to 16.5 K with an increase of the second stage of reaction temperature from 650 to 720 °C.
Development of monitor system for parallel-type superconducting level sensor for liquid hydrogen
Authors: Tanaka Naoki , Kajikawa Kazuhiro , Oguro Hidetoshi , Sugino Makoto , Nakanishi Tsutomu , Aoki Itsuo 
Published: October 2019

Abstract
We develop a monitor system to control a parallel-type superconducting (SC) level sensor and to indicate the level of liquid hydrogen in a container. The parallel-type level sensor is composed of an MgB2 wire and non-SC wire, which are vertically located in parallel and electrically connected in series. We assemble the monitor unit using a power supply, central processing unit (CPU), analog-to-digital (AD)/digital-to-analog (DA) converter, touch panel, voltage dividers and isolators. The terminal voltages of the MgB2 wire and non-SC wire with a constant current produced by the power supply are stored in the memory of CPU through the isolators, voltage dividers and AD converter. The liquid level is calculated in the CPU according to a pre-written program code. The obtained result is displayed on the touch panel and also output externally via the DA converter and isolator. Furthermore, the normal operation of the developed monitor system is validated using dummy voltages from an oscillator.
Fracture strength properties of (Gd,Y)BaCuO large single-grain bulk at liquid nitrogen temperature
Authors: Murakami A , Iwamoto I 
Published: October 2019

Abstract
In order to investigate the fracture strength properties of a (Gd,Y)BaCuO large single-grain bulk with 90 mm in diameter, bending tests were carried out at liquid nitrogen temperature 77 K for the specimens cut from the bulk sample. The large single-grain bulk was fabricated by RE compositional gradient technique to overcome the problem of undesirable nucleation apart from the seed crystal. One precursor that consisted of some regions with different Gd and Y contents was used for the fabrication. Bending tests for the plain and the V-notched specimens were carried out to evaluate the fracture strength and fracture toughness, respectively. The fracture strength values of the specimens that included the interface between two regions with different Gd and Y contents were not lower than those of the specimens that did not include the interface, which is similar to the bending test results at room temperature. The fracture strength values at 77 K were higher than those at room temperature.
Processing and Characterization of Charcoal Added Bulk MgB2 Superconductor
Authors: Longji Dadiel J , Muralidhar M , Arvapalli Sai Srikanth , Pavan Kumar Naik S , Murakami M 
Published: October 2019

Abstract
In this study, we focus on methods to further improve the flux pinning and critical current density (J
c) of disk shaped MgB2 bulk superconductors by a comparative study with locally obtained charcoal at optimized processing conditions. The doping of charcoal was varied at 0, 0.2, 0.4 and 0.6 wt%. Bulk MgB2 samples were produced by in-situ solid state reaction in Ar gas and ambient pressures at 775 °C, employing high purity of Mg metal and nano B powder mixed in a fixed ratio of Mg:B = 1:2 and optimal conditions. The phase has been investigated by X-ray diffractometer (XRD). The effects of the dopants on superconducting properties especially the field dependence of J
c have been determined by superconducting quantum interference device (SQUID) and critical temperature (T
c). Measurements of the magnetic susceptibility showed sharp superconducting transitions (ΔT
c ∼ 1 K). J
c at self-field and 20 K was determined to be ~280 and 467 kA/cm2 for the 0 and 0.4 wt% charcoal added samples respectively. The structural and superconducting results were correlated with the addition of charcoal in the final product.