35 research outputs found
Electric Field Switching of Magnon Spin Current in a Compensated Ferrimagnet
Manipulation of directional magnon propagation, known as magnon spin current,
is essential for developing magnonic memory and logic devices featuring
nonvolatile functionalities and ultralow power consumption. Magnon spin current
can usually be modulated by magnetic field or current-induced spin torques.
However, these approaches may lead to energy dissipation caused by Joule
heating. Electric-field switching of magnon spin current without charge current
is highly desired but very challenging to realize. By integrating magnonic and
piezoelectric materials, we demonstrate manipulation of the magnon spin current
generated by the spin Seebeck effect in the ferrimagnetic insulator Gd3Fe5O12
(GdIG) film on a piezoelectric substrate. We observe reversible electric-field
switching of magnon polarization without applied charge current. Through
strain-mediated magnetoelectric coupling, the electric field induces the
magnetic compensation transition between two magnetic states of the GdIG,
resulting in its magnetization reversal and the simultaneous switching of
magnon spin current. Our work establishes a prototype material platform that
pave the way for developing magnon logic devices characterized by all electric
field reading and writing and reveals the underlying physics principles of
their functions
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Different Physical Activity Subtypes and Risk of Metabolic Syndrome in Middle-Aged and Older Chinese People
Background: The prevalence of metabolic syndrome (MetS) is growing rapidly in China. Tai chi and dancing are common types of exercise among middle-aged and elderly Chinese. It remains unclear whether these activities are associated with a lower risk of MetS. Methodology/Principal Findings A total of 15,514 individuals (6,952 men, 8,562 women) aged 50 to 70 years from the Dongfeng-Tongji Cohort in Shiyan, China participated in a cross-sectional study. Physical activity and other lifestyle factors were assessed with semi-structured questionnaires during face-to-face interviews. MetS was defined by the current National Cholesterol Education Program/Adult treatment Panel III criteria for Asian Americans. The prevalence of MetS was 33.2% in the study population. In the multivariable-adjusted logistic regression analyses, total physical activity levels were monotonically associated with a lower odds of MetS [OR 0.75 comparing extreme quintiles, 95% confidence interval (CI) 0.66–0.86, P<0.001]. Compared with non-exercisers in a specific exercise type, jogging (OR 0.82, 95% CI 0.68–1.00, P = 0.046), tai chi (OR 0.72, 95% CI 0.60–0.88, P<0.001), and dancing (OR 0.56, 95% CI 0.47–0.67, P<0.001) were associated with significantly lower odds of MetS. Furthermore, each 1–h/week increment in tai chi and dancing was associated with a 5% (95% CI 2%–9%) and a 9% (95% CI 6%, 12%) lower risk of MetS. Conclusions/Significance: Jogging, tai chi and dancing are associated with a significantly lower risk of having MetS in middle-aged and older Chinese. Future intervention studies should consider the role of jogging, tai chi and dancing in preventing MetS
Anomalous structural evolution and glassy lattice in mixed-halide hybrid perovskites
Hybrid halide perovskites have emerged as highly promising photovoltaic materials because of their exceptional optoelectronic properties, which are often optimized via compositional engineering like mixing halides. It is well established that hybrid perovskites undergo a series of structural phase transitions as temperature varies. In this work, the authors find that phase transitions are substantially suppressed in mixed-halide hybrid perovskite single crystals of MAPbI3-xBrx (MA = CH3NH3+ and x = 1 or 2) using a complementary suite of diffraction and spectroscopic techniques. Furthermore, as a general behavior, multiple crystallographic phases coexist in mixed-halide perovskites over a wide temperature range, and a slightly distorted monoclinic phase, hitherto unreported for hybrid perovskites, is dominant at temperatures above 100 K. The anomalous structural evolution is correlated with the glassy behavior of organic cations and optical phonons in mixed-halide perovskites. This work demonstrates the complex interplay between composition engineering and lattice dynamics in hybrid perovskites, shedding new light on their unique properties.Peer ReviewedPostprint (published version
Economical and balanced production in smart Petroleum Cyber–Physical System
In Petroleum Cyber–Physical Social workflows, monetary profit optimization is essential. In this work, a production optimization approach for the Petroleum Cyber–Physical System is proposed which spans the field production to the petroleum social market. Dynamic Programming technique, Linear Programming technique and Stochastic Programming technique are first utilized to improve the monetary profit for a single petroleum company. A market-driven petroleum social workflow aware production optimization technique is then proposed to facilitate profit optimization among multiple petroleum companies. The case study result shows that the monetary income can be increased up to 311.67% in an one year time span
Offshore oil spill monitoring and detection: Improving risk management for offshore petroleum cyber-physical systems: (Invited paper)
© 2017 IEEE. Petroleum industry has started to embrace the advanced Petroleum Cyber-Physical System (CPS) technologies. Offshore petroleum CPS is particularly difficult to build, mainly due to the challenge in detecting and preventing offshore oil leaking. During the oil exploration and transportation process, the remote multi-sensing technology is typically used for leak detection, enabling the underwater modeling of an offshore petroleum CPS. However, such a technology suffers from insufficient remote sensing resources and large computational overhead. In this work, a cross entropy optimization based leak detection technique is proposed to detect the oil leak, which also facilitates the understanding of the oil leak induced marine pollution. Experimental results on a real Penglai oil spill event demonstrate that the proposed technique can effectively identify the sources of oil spills with accuracy of up to 90.78%
The complete mitochondrial genome of Pethia padamya (Actinopteri, Cyprinidae)
Pethia padamya (Kullander and Britz, 2008) is a freshwater fish distributed in the Mekong River basin of Thailand. It has beautiful colors and can be used as an ornamental fish. The complete mitochondrial genome of P. padamya was determined using next-generation sequencing technology and its characteristics were analyzed. The mitochondrial genome is a closed circular molecule comprising 16,792 bp, including 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and a major non-coding region. The overall base composition of the mitochondrial genome is 32.47% A, 25.39% C, 26.08% T, and 16.06% G, with a high A + T bias of 58.55%. Phylogenetic analysis revealed P. padamya as a sister group of Pethia conchonius+(Pethia ticto+Pethia cumingii) and Pethia gelius with maximal support, providing support for the monophyly of the genus Pethia based on concatenated nucleotide sequences. The results of this study proved the monophyly of the genus Pethia. These data for the first time provide information on the complete mitochondrial genome of P. padamya and can contribute to further studies on the biodiversity and management of P. padamya
Assimilation of GNSS PWV with NCAR-RTFDDA to Improve Prediction of a Landfall Typhoon
Precipitable water vapor (PWV) retrieved from ground-based global navigation satellite system (GNSS) stations acquisition signal of a navigation satellite system provides high spatial and temporal resolution atmospheric water vapor. In this paper, an observation-nudging-based real-time four-dimensional data assimilation (RTFDDA) approach was used to assimilate the PWV estimated from GNSS observation into the WRF (Weather Research and Forecasting) modeling system. A landfall typhoon, “Mangkhut”, is chosen to evaluate the impact of GNSS PWV data assimilation on its track, intensity, and precipitation prediction. The results show that RTFDDA can assimilate GNSS PWV data into WRF to improve the water vapor distribution associated with the typhoon. Assimilating the GNSS PWV improved the typhoon track and intensity prediction when and after the typhoon made landfall, correcting a 5–10 hPa overestimation (too deep) of the central pressure of the typhoon at landfall. It also improved the occurrence and the intensity of the major typhoon spiral rainbands
Assimilation of GNSS PWV with NCAR-RTFDDA to Improve Prediction of a Landfall Typhoon
Precipitable water vapor (PWV) retrieved from ground-based global navigation satellite system (GNSS) stations acquisition signal of a navigation satellite system provides high spatial and temporal resolution atmospheric water vapor. In this paper, an observation-nudging-based real-time four-dimensional data assimilation (RTFDDA) approach was used to assimilate the PWV estimated from GNSS observation into the WRF (Weather Research and Forecasting) modeling system. A landfall typhoon, “Mangkhut”, is chosen to evaluate the impact of GNSS PWV data assimilation on its track, intensity, and precipitation prediction. The results show that RTFDDA can assimilate GNSS PWV data into WRF to improve the water vapor distribution associated with the typhoon. Assimilating the GNSS PWV improved the typhoon track and intensity prediction when and after the typhoon made landfall, correcting a 5–10 hPa overestimation (too deep) of the central pressure of the typhoon at landfall. It also improved the occurrence and the intensity of the major typhoon spiral rainbands
The Aspergillus flavus Phosphatase CDC14 Regulates Development, Aflatoxin Biosynthesis and Pathogenicity
Reversible protein phosphorylation is known to play important roles in the regulation of various cellular processes in eukaryotes. Phosphatase-mediated dephosphorylation are integral components of cellular signal pathways by counteracting the phosphorylation action of kinases. In this study, we characterized the functions of CDC14, a dual-specificity phosphatase in the development, secondary metabolism and crop infection of Aspergillus flavus. Deletion of AflCDC14 resulted in a growth defect and abnormal conidium morphology. Inactivation of AflCDC14 caused defective septum and failure to generate sclerotia. Additionally, the AflCDC14 deletion mutant (ΔCDC14) displayed increased sensitivity to osmotic and cell wall integrity stresses. Importantly, it had a significant increase in aflatoxin production, which was consistent with the up-regulation of the expression levels of aflatoxin biosynthesis related genes in ΔCDC14 mutant. Furthermore, seeds infection assays suggested that AflCDC14 was crucial for virulence of A. flavus. It was also found that the activity of amylase was decreased in ΔCDC14 mutant. AflCDC14-eRFP mainly localized to the cytoplasm and vesicles during coidial germination and mycelial development stages. Taken together, these results not only reveal the importance of the CDC14 phosphatase in the regulation of development, aflatoxin biosynthesis and virulence in A. flavus, but may also provide a potential target for controlling crop infections of this fungal pathogen