The discovery of the spin Hall effect
enabled the efficient generation and manipulation of the spin current. More recently, the magnetic spin Hall effect
was observed in non-collinear ...antiferromagnets, where the spin conservation is broken due to the non-collinear spin configuration. This provides a unique opportunity to control the spin current and relevant device performance with controllable magnetization. Here, we report a magnetic spin Hall effect in a collinear antiferromagnet, Mn
Au. The spin currents are generated at two spin sublattices with broken spatial symmetry, and the antiparallel antiferromagnetic moments play an important role. Therefore, we term this effect the 'antiferromagnetic spin Hall effect'. The out-of-plane spins from the antiferromagnetic spin Hall effect are favourable for the efficient switching of perpendicular magnetized devices, which is required for high-density applications. The antiferromagnetic spin Hall effect adds another twist to the atomic-level control of spin currents via the antiferromagnetic spin structure.
Out-of-plane spin polarization σ
has attracted increasing interests of researchers recently, due to its potential in high-density and low-power spintronic devices. Noncollinear antiferromagnet (AFM), ...which has unique 120° triangular spin configuration, has been discovered to possess σ
. However, the physical origin of σ
in noncollinear AFM is still not clear, and the external magnetic field-free switching of perpendicular magnetic layer using the corresponding σ
has not been reported yet. Here, we use the cluster magnetic octupole in antiperovskite AFM Mn
SnN to demonstrate the generation of σ
. σ
is induced by the precession of carrier spins when currents flow through the cluster magnetic octupole, which also relies on the direction of the cluster magnetic octupole in conjunction with the applied current. With the aid of σ
, current induced spin-orbit torque (SOT) switching of adjacent perpendicular ferromagnet is realized without external magnetic field. Our findings present a new perspective to the generation of out-of-plane spin polarizations via noncollinear AFM spin structure, and provide a potential path to realize ultrafast high-density applications.
The effect of Al and Si on microstructure evolution, mechanical, magnetic properties, and electrical resistivity of non-equimolar Fe
2
CoNi(AlSi)
x
(
x
= 0–0.4) high-entropy alloys (HEAs) was ...studied. This series of Fe
2
CoNi(AlSi)
x
HEAs has a dual-phase structure and shows an excellent combination of mechanical and soft magnetic properties. In particular, the Fe
2
CoNi(AlSi)
0.4
HEA exhibits high compressive yield strength
σ
0.2
(887.6 MPa), fracture strain (39%), electrical resistivity
ρ
(84.8 μΩ cm),
M
s
(155.2 emu/g), and
H
c
(1.7 Oe). This work may provide a promising method of developing HEAs with an optimal balance of mechanical and soft magnetic properties under the addition of Al and Si suitable for wide-range industrial applications.
Understanding the atmospheric new particle formation (NPF) process within the global range is important for revealing the budget of atmospheric aerosols and their impacts. We investigated the ...seasonal characteristics of NPF in the urban environment of Beijing. Aerosol size distributions down to ∼1 nm and H2SO4 concentration were measured during 2018–2019. The observed formation rate of 1.5 nm particles (J 1.5) is significantly higher than those in the clean environment, e.g., Hyytiälä, whereas the growth rate is not significantly different. Both J 1.5 and NPF frequency in urban Beijing show a clear seasonal variation with maxima in winter and minima in summer, while the observed growth rates are generally within the same range around the year. We show that ambient temperature is a governing factor driving the seasonal variation of J 1.5. In contrast, the condensation sink and the daily maximum H2SO4 concentration show no significant seasonal variation during the NPF periods. In all four seasons, condensation of H2SO4 and (H2SO4) n (amine) n clusters contributes significantly to the growth rates in the sub-3 nm size range, whereas it is less important for the observed growth rates of particles above 3 nm. Therefore, other species are always needed for the growth of larger particles.
Low-grade metamorphosed Cretaceous sedimentary records of forearc basin systems in the eastern part of the Transhimalaya (Gangdese) arc system have not been reported yet, impairing understanding of ...the Mesozoic-Cenozoic convergent margin processes along the southern margin of Asia. This study incorporates observations from petrography, stratigraphy, sedimentology, and analyses of detrital-zircon geochronology and bulk-rock Sr-Nd isotope for a series of low-grade metamorphosed sedimentary rocks referred to as the Lilong succession in the eastern Yarlung Zangbo suture zone, east of Langxian, in southeastern Tibet, China. Field observations reveal that this unit has three different lithological associations (I, II, and III) including gravel-coarse sandy inner-middle submarine fan facies, sandy-muddy middle-outer submarine fan facies, and silty-muddy outer submarine fan and/or deep sea plain facies moving higher in the succession. Detrital-zircon geochronology indicates a maximum depositional age of ~110 Ma and the absence of younger zircons that are dominant in the Gangdese batholith north of the basin suggests the minimum depositional age ~ 85 Ma, comprising an interval of the Albian-Santonian age. Volcanic and granitic clasts in sandstones/conglomerates, εNd(0) values (−0.09 and 4.6) and 87Sr/86Sr ratios (0.704105–0.704770) of slates, and detrital zircon age spectra (mainly 100–140 Ma) demonstrate provenance from the central-northern and southern Lhasa Terrane. In addition, there is evidence for recycling of cherty beds of the Chongdui Formation. Similarities between provenance, lithofacies, and tectonic setting lead us to interpret that the newly identified remnant unit correlates to the Ngamring Formation in the Xigaze forearc basin. When taking into account the lower Bomi Group and Nyingchi complex, we propose that the Lilong succession and the metamorphosed composite in the eastern Himalayan syntaxis are counterpart remnants of the eastern Xigaze forearc basin system, which are different from the two forearc basin systems in the western Himalaya.
•The Albian-Santonian Lilong succession identified near the E Himalaya syntaxis•The Lilong succession deposited in a submarine fan system•The Lilong succession developed in a forearc basin with sources of Lhasa Terrane•Forearc basin system in central and E Himalaya differs from that in W Himalaya
Neo-Tethyan paleo-seamounts remain poorly understood due to the scarcity of key holistic evidence although some cases have been reported. This work focuses on a Middle Permian (Guadalupian) composite ...seamount in the central Yarlung Zangbo Suture Zone, using textures and sequences of its basaltic basement and carbonate cap to characterize the development of the oceanic crust. We conducted field investigations, lithological studies, and geochemical analyses of a huge composite rock block (the Buma paleo-seamount) north of Lang Co, Ngamring, Tibet. Results show that the basement rocks are mainly subaqueously erupted, tholeiitic basalts, which are very similar to the Hawaiian oceanic island basalts (OIB-types) in terms of geochemistry and tectonic setting; and the cap rocks are characterized by four general sedimentary facies and ten limestone microfacies, all of which are primarily of shallow marine nature. Four different contact relationships between basement and cap rocks are further recognized as “regular”, “scouring”, “brecciation”, and “karstification” types. Together, they demonstrate that multiple complete sequences of basalt basement and sedimentary cap, rich in bryozoans (reef/atoll) and crinoids exist, representing the composite seamount in the central Yarlung Zangbo Suture Zone. At least eight sets of seamount sub-sequences are superimposed as submerged and subaerial types, recording the oceanic crustal evolution of the Neo-Tethys Ocean during the Guadalupian epoch. Particularly, residual basaltic and karst breccia indicate subaerial exposure and, thus, prove an island stage. Taking into account the average mature seamount lifespan of ∼26 Ma and the complete sequence of the newly recognized Buma seamount in an intraplate setting, we propose that the incipient opening of the eastern Neo-Tethys could have taken place much earlier than the Guadalupian (Middle Permian), likely during the Cisuralian (Early Permian) or even earlier.
•Middle Permian composite seamounts verified within Yarlung Zangbo suture zone.•Eight sets of seamount sequences distinguished by OIB-type basement-limestone cap.•Early Permian incipient opening suggested for eastern Neo-Tethys Ocean.
•Developed innovative structure with curved vanes and cover with bumps.•The reliable DEM model of static spreading was established for UAV spreading.•The working mechanism of disc spreader was ...proved.•A high-performance spreader was developed with a uniformity CV of 14.4%.•A method to improve the uniformity of disc spreader was summarized.
Fertilizer applications from unmanned aerial vehicles (UAVs) have become increasingly common in crop farming. With the rise in UAV capacities for payload and batteries, and increases in application flight speeds, the demands on spreader performance, particularly discharge rate and uniformity, have grown. To address this, a design was developed which incorporates a horizontal screw auger, curved and straight vanes on the disc, and a cover with bumps. This was designed to enhance the distribution uniformity of a large discharge rate disc spreader for UAV fertilizer application. The discharge device featuring the horizontal screw auger achieved high, precise discharge rates within a compact structure. The fertilizer was sequentially scraped by the vanes, with the curved vanes delaying particle release as batches. Upon release, the fertilizer batches collided with the cover, causing some to rebound and form a non-hollow circular spreading distribution. This two-step process transformed the spreading distribution from arc-shaped to non-hollow circular, thereby enhancing the spreader's uniformity. Simulation using the discrete element method (DEM) investigated how innovative structures improve distribution uniformity. A static spreading numerical model, established through a DEM, explored the impact of four factors (deflection angle of curved vanes, thickness, number, and position of bumps) on spreading distribution. Simulation experiments, conducted using a Box-Behnken design (BBD), optimized bump parameters. The spreader, mounted on a DJI T60 UAV, underwent single-route flight tests, assessing the effects of screw auger rotation rate, disc rotation rate, and flight speed on distribution uniformity. Results indicated that disc rotation rate and flight speed had negligible effects on fertilizer distribution uniformity, while screw auger rotation rate had a significant effect. Recommendations were made to increase disc and flight speeds for low fertilization application rates, enabling the screw auger to work at a higher rotation rate and achieve better uniformity. Field tests demonstrated that a compound fertilizer achieved a discharge rate of 190.02 kg/min, with an 8 m operation width and low coefficient of variation (CV) of 14.04 % for urea application and 14.68 % for compound fertilizer application. The spreader exhibited good uniformity and robustness across various fertilizers and rates. This research successfully developed a high-performance spreader for large-load UAVs, with significant implications for UAV applications in agriculture.
Cavity magnon polaritons are mixed quasiparticles that arise from the strong coupling between cavity photons and quantized magnons. Combining high-speed photons with long-coherence-time magnons, such ...polaritons promise to be a potential candidate for quantum information processing. For harnessing coherent information contained in spatially distributed polariton states, it is highly desirable to manipulate cavity magnon polaritons in a two-dimensional system. Here, we demonstrate that tunable cavity magnon polariton transport can be achieved by strongly coupling magnons to microwave photons in a cross-cavity. An analog to the dynamic Hall effect has been demonstrated in a planar cavity spintronic device, where the propagation of cavity-magnon-polaritons is deflected transversally due to hybrid magnon-photon dynamics. Implementing this device as a Michelson-type interferometer using the coherent nature of the dynamic Hall and longitudinal signals, we have developed a proof-of-principle logic device to control the amplitude of cavity-magnon-polaritons by encoding the input microwave phase.
Environmental pollution of trace elements has become of main concern due to the adverse effects. To estimate the impact of PM2.5-bound trace elements on human health, a time-stratified case-crossover ...study has been designed to examine the short-term associations between 28 elements and asthma hospitalizations from January 2019 to November 2021 in Xiamen, China. This research summarized the major components that pose health risks in different seasons and took risk assessment for different groups. We found that an inter-quartile range (IQR) increase of Ca, Fe, Mn, Pd, Si, and Ti was positively associated with the incidence of asthma in the lag of 0–4 days. In winter, the elements that predisposed the population to asthma attack were the most, such as Al, Ba, Ca, Cr, Cu, Fe, K, Mn, Pd, Si, and Ti, and these elements are at higher risk for longer periods of time. The discrepancy in risk levels and major elements of asthma diagnosis among various age groups were also found in this work. Our results provided insights into the development of specific policies to reduce the risk of asthma attacks due to exposure to PM2.5-bound trace elements.
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