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Background and purposeIntracerebral hemorrhage (ICH) is a severe form of stroke that remains understudied in the young adults. We aimed to investigate the clinical presentation, and risk factors associated with ICH in this age group and compare them to older patients.MethodsOur study included ICH patients admitted between March 2016 and December 2021 in the First Affiliated Hospital of Chongqing Medical University from our ongoing prospective cohort database. Demographic characteristics, etiology, risk factors, and clinical outcomes were compared between elderly and young patients. Furthermore, logistic regression analysis was employed to explore risk factors associated with the functional outcome at 3-months.ResultsWe selected 1,003 patients (mean age, 59.9 ±13.8 years old), 746 (74.4%) patients were aged >50 years. The logistic regression analysis showed young patients have a higher proportion of secondary ICH, higher white blood cell count and higher body mass index (BMI), but less diabetes mellitus. Of all patients, predictors of 3-month functional independence was first-ever ICH and age ≤50 years. The history of nephropathy and stroke, higher baseline NIHSS score, larger hematoma volume, and the presence of hydrocephalus were associated with poor outcomes. And the white blood cell count could significantly influence the prognosis among young ICH patients. Three-month functional outcome based on modified Rankin scale score was better in young patients than the elderly (OR, 1.232; 95% CI, 1.095–1.388; p < 0.001).ConclusionsThe highest incidence of ICH occurs in the age groups of 50–59 and 60–69. ICH in young adults had higher white blood cell and BMI compared to the elderly, and differs in etiological distribution. The young patients also had similar short-term mortality but more favorable functional outcomes than the elderly. Furthermore, NIHSS score and larger hematoma volumes were associated with poor outcome in all patients.

Despite various known topological polar structures, the dynamic property of isolated ones is still poorly understood. Here, the authors show the controlled nucleation and ability to move of isolated three-fold vertices under an applied electric field.

The piezoelectricity of PVDF composites is mainly determined by the crystalline phases and spontaneous polarization. Here, the authors propose a Ti3C2Tx anchoring method to modulate the molecular interactions and conformation of polymer matrix.

Abstract Many functional and quantum materials derive their functionality from the responses of both their electronic and lattice subsystems to thermal, electric, and mechanical stimuli or light. Here we propose a dynamical phase-field model for predicting and modeling the dynamics of simultaneous electronic and structural processes and the accompanying mesoscale pattern evolution under static or ultrafast external stimuli. As an illustrative example of application, we study the transient dynamic response of ferroelectric domain walls excited by an ultrafast above-bandgap light pulse. We discover a two-stage relaxational electronic carrier evolution and a structural evolution containing multiple oscillational and relaxational components across picosecond to nanosecond timescales. The phase-field model offers a general theoretical framework which can be applied to a wide range of functional and quantum materials with interactive electronic and lattice orders and phase transitions to understand, predict, and manipulate their ultrafast dynamics and rich mesoscale evolution dynamics of domains, domain walls, and charges.

Syn-subduction basins bear significant implications to understand tectonic evolution of any fossil subduction zone. The late Paleozoic to early Mesozoic (Paleo-Tethyan) tectonics of the eastern and southeastern Tibetan Plateau (i.e., the Sanjiang Orogenic Belt) is featured by ocean-continent subduction systems. A huge pile of volcanic-absent sedimentary succession developed in the middle segment of the Sanjiang orogenic belt, its age and tectonic nature remain unclear. Detailed geological mapping and zircon U-Pb dating results demonstrate that the early Late Triassic volcanic-absent succession comprises the nonmarine Maichuqing Formation in the lower part and the shallow marine Sanhedong Formation in the upper part. The Maichuqing Formation consists of coarse to fine-grained sandstone, siltstone and mudstone with abundant basal erosional surfaces, trough and planar cross-beddings, ripples, mudcracks, and plant fragments. The Sanhedong Formation comprises predominantly bioclastic limestones interlayered with marl, calcareous-muddy siltstone, and calcareous sandstone with abundant bivalve fossils. Syn-sedimentation deformation structures, such as slump folds and associated normal faults are common, suggesting intense tectonism during deposition. Synthesizing sedimentary data, paleocurrent and provenance results, combined with other available data, demonstrate that the volcanic-absent succession deposited within a retro-foreland basin along the rear part of the Permian-Triassic Jomda-Weixi-Yunxian arc in response to flat-subduction of the Paleo-Tethyan Ocean during the early Late Triassic time.

Abstract Piezoelectric nanocomposites with oxide fillers in a polymer matrix combine the merit of high piezoelectric response of the oxides and flexibility as well as biocompatibility of the polymers. Understanding the role of the choice of materials and the filler‐matrix architecture is critical to achieving desired functionality of a composite towards applications in flexible electronics and energy harvest devices. Herein, a high‐throughput phase‐field simulation is conducted to systematically reveal the influence of morphology and spatial orientation of an oxide filler on the piezoelectric, mechanical, and dielectric properties of the piezoelectric nanocomposites. It is discovered that with a constant filler volume fraction, a composite composed of vertical pillars exhibits superior piezoelectric response and electromechanical coupling coefficient as compared to the other geometric configurations. An analytical regression is established from a linear regression‐based machine learning model, which can be employed to predict the performance of nanocomposites filled with oxides with a given set of piezoelectric coefficient, dielectric permittivity, and stiffness. This work not only sheds light on the fundamental mechanism of piezoelectric nanocomposites, but also offers a promising material design strategy for developing high‐performance polymer/inorganic oxide composite‐based wearable electronics.

Deterministic switching of a magnetic vortex with an electric field is challenging because electric fields cannot break time-reversal symmetry. Here we demonstrate, using phase-field simulations, a deterministic switching of the vortex chirality in a triangle-shaped nanomagnet by applying an electric field to its underlying ferroelectric layer. The nanomagnet is juxtaposed with an overlying antiferromagnetic layer to acquire an exchange bias from their interface. The simulations show that such deterministic electrically-driven magnetic vortex chirality switching is enabled by a synergistic effect of the electric-field-induced strain from the ferroelectric, the three-fold in-plane shape anisotropy of the nanomagnet, and the exchange-bias field.

The morphotropic phase boundary (MPB), separating two ferroic phases with rhombohedral and tetragonal crystal symmetries, has been utilized extensively in ferroelectrics because it can lead to high-performance piezoelectricity. Recently, a parallel ferromagnetic MPB was experimentally reported and was suggested that the optimal point for magneto-mechanical applications might lies on the rhombohedral side. However, the insight of the domain structures and switching mechanism near ferromagnetic MPB is still unclear. In this work, phase-field micromagnetic microelastic modeling was employed to simulate the domain formation and magnetization switching of (Tb0.27Dy0.73)Fe2, whose composition is around the rhombohedral side of ferromagnetic MPB. The results show that four kinds of domains of the rhombohedral phase automatically form twins of {110} or {100} boundaries with 71° and 109° domain walls after a process of nucleation and growth. The rhombohedral domain evolution and phase volume fraction under the external field of 120 kA/m along different directions are investigated. In ferromagnetics subject to an alternating magnetic field, domain magnetization switches to cause a magnetization hysteresis loop and an associated butterfly magnetostriction loop with the alternating magnetic field.

Successive indentations of Eurasia by India have led to the Tibet-Himalaya E–W orthogonal collision belt and the SE Tibetan Plateau N–S oblique collision belt along the frontal and eastern edges of the indenter, respectively. The belts exhibit distinctive lithospheric structures and tectonic evolutions. A comprehensive compilation of available geological and geophysical data reveals two sudden tectonic transitions in the early Eocene and the earliest Miocene, respectively, of the tectonic evolution of the orthogonal belt. Synthesizing geological and geochronological data helps us to suggest a NEE–SWW trending, ~450 km-long, ~250 km-wide magmatic zone in SE Tibet, which separates the oblique collision belt (eastern and SE Tibet) into three segments of distinctive seismic structures including the mantle and crust anisotropies. The newly identified Yongping basin is located in the central part of the magmatic zone. Geochronological and thermochronological data demonstrate that (1) this basin and the magmatic zone started to form at ~48 Ma likely due to NNW–SSE lithosphere stretching according to the spatial coincidence of the concentrated mantle-sourced igneous rocks on the surface with the seismic anomalies at depth; and (2) its fills was shortened in the E–W direction since ~23 Ma. These two dates correspond to the onset of the first and second tectonic transitions of the orthogonal collision belt. As such, both the orthogonal and oblique belts share a single time framework of their tectonic evolution. By synthesizing geological and geophysical data of both collision belts, the indenting process can be divided into three stages separated by two tectonic transitions. Continent–continent collision as a piston took place exclusively during the second stage. During the other two stages, the India lithosphere underthrust beneath Eurasia.

Combining a perovskite ferroelectric with moderate piezoelectric properties and a nonpiezoelectric pervoskite relaxor can create a highly piezoelectric material. Here, the authors help explain this unusual result by quantifying how polar nanoregions in the material contribute to its piezoelectric response.

Ferroelectric reliability must be solved prior to practical non-volatile electronic devices based on magnetoelectric multiferroics. Here, Hsiehet al. report a long lasting ferroelectric retention in the heteroepitaxially constrained multiferroic mesocrystal.

FeRh is a unique alloy which shows temperature dependent phase transition magnetic properties. The lattice parameter (a) of this CsCl-type (B2) structure is 4.1712 Å. It undergoes a first order transition from antiferromagnetic (AFM) to ferromagnetic (FM) order at around 370K and hysteretic behavior while cooling and heating. This meta-magnetic transition of FeRh is accompanied by an isotropic expansion in the unit cell volume, which indicates strong coupling between magnetic and structural properties of FeRh. Consequently, the magnetic and transport properties, such as magnetoresistance (MR), are changed during the transition. Due to its unique thermo-magnetic behaviors, FeRh is very important for future spintronic devices. The structure could be applicable for MR devices such as memory, sensors, and many other applications. It is critical to understand how to systematically influence phase transition of FeRh from naturally applied strains. Here, we investigate magnetic properties of FeRh in different strain environments induced by the substrates with different lattice parameters. The study was performed using synchrotron radiation, temperature dependent magnetometry, and magnetic scanning probe microscopy in addition to Landau theory calculations. We found that the naturally induced strains could modulate the magnetic phase locally and globally. The presence of the segments from the nucleation of the ferromagnetic domains, with a very thin layer in the antiferromagnetic matrix and the domain growth, were observed gradually. Using the systematic phenomena, it could be used for immediate applications in the future generation of phase change random access memory (PC-RAM) devices.

The processes by which lamprophyres and associated carbonatites are generated remain subject to debate. The Wase Basin on the SE Tibetan Plateau contains trachytes, rhyolites, and minor carbonatites that were emplaced at 37-36 Ma. Coeval lamprophyre dikes are widespread in the adjacent regions. Geochemically and petrographically, both the extrusive trachytes and dikes can be classified as lamprophyre. The numerous millimeter-sized SiO2-rich and calcite-rich ocelli that occur within the trachytes and dikes are solidified pseudomorphs of felsic and calcic melt drops, respectively. These ocelli combined with inherited granitic zircons suggest magma mixing between the calcic melt or felsic melt and basaltic melt. Petrographic evidence, mineral compositions, and zircon textures and U-Pb ages (827-682 Ma) suggest that the felsic melt and the calcic melt were generated by rapid H2O-saturated partial melting of Neoproterozoic granite and limestone, respectively, at >800 °C and <2 kbar, according to available experimental data. These melts were separated from each other and were stored at upper crustal depths, forming a zone of transient magma lenses or parcels. Melts mixed when an ascending basaltic magma intersected this zone. Reaction between the basaltic melt and the calcic melt occurred when they mixed, which formed clinopyroxene of predominantly diopsidehedenbergite solid solution. The observed heterogeneity of the upper crust combined with the variable degrees of magma mixing account for the great chemical diversity of the lamprophyres of SE Tibet. This model sheds new light on the petrogenesis of other lamprophyre- carbonatite associations elsewhere. [ABSTRACT FROM AUTHOR]

New properties and exotic quantum phenomena can form due to periodic nanotextures, including Moire patterns, ferroic domains, and topologically protected magnetization and polarization textures. Despite the availability of powerful tools to characterize the atomic crystal structure, the visualization of nanoscale strain-modulated structural motifs remains challenging. Here, we develop nondestructive real-space imaging of periodic lattice distortions in thin epitaxial films and report an emergent periodic nanotexture in a Mott insulator. Specifically, we combine iterative phase retrieval with unsupervised machine learning to invert the diffuse scattering pattern from conventional X-ray reciprocal-space maps into real-space images of crystalline displacements. Our imaging in PbTiO3/SrTiO3 superlattices exhibiting checkerboard strain modulation substantiates published phase-field model calculations. Furthermore, the imaging of biaxially strained Mott insulator Ca2RuO4 reveals a strain-induced nanotexture comprised of nanometer-thin metallic-structure wires separated by nanometer-thin Mott-insulating-structure walls, as confirmed by cryogenic scanning transmission electron microscopy (cryo-STEM). The nanotexture in Ca2RuO4 film is induced by the metal-to-insulator transition and has not been reported in bulk crystals. We expect the phasing of diffuse X-ray scattering from thin crystalline films in combination with cryo-STEM to open a powerful avenue for discovering, visualizing, and quantifying the periodic strain-modulated structures in quantum materials. [ABSTRACT FROM AUTHOR]

The demand for a new generation of high-temperature dielectric materials toward capacitive energy storage has been driven by the rise of high-power applications such as electric vehicles, aircraft, and pulsed power systems where the power electronics are exposed to elevated temperatures. Polymer dielectrics are characterized by being lightweight, and their scalability, mechanical flexibility, high dielectric strength, and great reliability, but they are limited to relatively low operating temperatures. The existing polymer nanocomposite-based dielectrics with a limited energy density at high temperatures also present a major barrier to achieving significant reductions in size and weight of energy devices. Here we report the sandwich structures as an efficient route to high-temperature dielectric polymer nanocomposites that simultaneously possess high dielectric constant and low dielectric loss. In contrast to the conventional single-layer configuration, the rationally designed sandwich-structured polymer nanocomposites are capable of integrating the complementary properties of spatially organized multicomponents in a synergistic fashion to raise dielectric constant, and subsequently greatly improve discharged energy densities while retaining low loss and high charge-discharge efficiency at elevated temperatures. At 150 °C and 200 MV m-1, an operating condition toward electric vehicle applications, the sandwich-structured polymer nanocomposites outperform the state-of-the-art polymer-based dielectrics in terms of energy density, power density, charge-discharge efficiency, and cyclability. The excellent dielectric and capacitive properties of the polymer nanocomposites may pave a way for widespread applications in modern electronics and power modules where harsh operating conditions are present. [ABSTRACT FROM AUTHOR]

In general, a dielectric material will eject (or absorb) heat when an electric field is applied and absorb (or eject) heat when the field is removed, under isothermal condition, which is known as the normal (or negative) electrocaloric (EC) effect. For some applications, it is highly desired that an EC material will absorb heat (cooling the surrounding) without subsequent heating under an electric pulse. Here, we show that such an EC material can be realized in a properly designed hybrid normal ferroelectric/relaxor ferroelectric polymer blend in which the normal ferroelectric component induces dipole ordering in the relaxor polymer in the poled state, which can be switched to a de-poled state by an external field. More importantly, the de-poled state can be maintained by the relaxor component when the de-poling field is removed. Consequently, the hybrid blend exhibits a large cooling (an isothermal entropy change ΔS=11.5 J kg–1K–1) without the subsequent heating upon the application of an electric pulse. [ABSTRACT FROM AUTHOR]

Exploring the dynamic responses of a material is of importance to both understanding its fundamental physics at high frequencies and potential device applications. Here we develop a phase-field model for predicting the dynamics of ferroelectric materials and study the dynamic responses of ferroelectric domains and domain walls subjected to an ultrafast electric-field pulse. We discover a transition of domain evolution mechanisms from pure domain growth at a relatively low field to combined nucleation and growth of domains at a high field. We derive analytical models for the two regimes which allow us to extract the effective mass and damping coefficient of ferroelectric domain walls. The exhibition of two regimes for the ferroelectric domain dynamics at low and high electric fields is expected to be a general phenomenon that would appear for ferroic domains under other ultrafast stimuli. The present Letter also offers a general framework for studying domain dynamics and obtaining fundamental properties of domain walls and thus for manipulating the dynamic functionalities of ferroelectric materials. [ABSTRACT FROM AUTHOR]

Switching the magnetization with an electric field in multiferroic heterostructures is desirable since it provides a possibility to achieve information storage with lower power consumption than traditional spintronic devices by using an electric current to drive magnetization rotation. Most of the existing studies, however, have been on multiferroic heterostructures containing either a single magnetic island or spatially well-separated multiple magnetic islands, where the effect of long-range magnetostatic interactions among magnetic islands (i.e. so-called cross-talking) can be ignored. Here we employ phase-field simulations to study the effect of magnetic interactions among islands on the electric-field-controlled magnetization switching in multiferroic heterostructures. As an example, we consider two interactive Co40Fe40B20(CoFeB) magnetic nanoislands grown on a PMN-PT ((0 0 1)-oriented Pb(Mg1/3Nb2/3)0.7Ti0.3O3) ferroelectric layer. We find that the distance between two neighboring nanoislands has to exceed a critical value to achieve an independent 180° magnetization switching in each nanoisland. The present work provides guidance for further experimental studies on the electric field control of magnetization and design of novel multiferroic devices. [ABSTRACT FROM AUTHOR]

Using time- and spatially resolved hard x-ray diffraction microscopy, the striking structural and electrical dynamics upon optical excitation of a single crystal of BaTiO3 are simultaneously captured on subnanoseconds and nanoscale within individual ferroelectric domains and across walls. A large emergent photoinduced electric field of up to 20×106 V/m is discovered in a surface layer of the crystal, which then drives polarization and lattice dynamics that are dramatically distinct in a surface layer versus bulk regions. A dynamical phase-field modeling method is developed that reveals the microscopic origin of these dynamics, leading to gigahertz polarization and elastic waves traveling in the crystal with sonic speeds and spatially varying frequencies. The advances in spatiotemporal imaging and dynamical modeling tools open up opportunities for disentangling ultrafast processes in complex mesoscale structures such as ferroelectric domains. [ABSTRACT FROM AUTHOR]