Through analysis of Rayleigh wave and Love wave Green＇s functions estimated from ambient noise tomography, we obtain radial anisotropy and shear wave velocity structure beneath the northeastern ...Tibetan Plateau. With two hundred and twenty three broadband seismic stations deployed by China Earthquake Administration, a collaborative seismic experiment of northern Tibet（ACSENT） experiment and northeastern Tibet seismic（NETS） experiment provide the unprecedented opportunity to resolve the spatial distribution of the radial anisotropy within the crust of the northeastern Tibetan Plateau. Discrepancies between Love（sh） and Rayleigh（sv） wave velocities show complex anisotropic patterns associated with the dynamic processes of the collision between the Indian and Eurasian plates：（1） In the upper crust, V（sv）〉V（sh） anisotropy is dominant throughout the study area which probably reflects fossil microcracks induced by the uplift, folding and erosion geodynamic processes;（2） in the middle crust, V（sh）〉V（sv） observed beneath the Songpan-Ganzi terrane and the northwestern Qilian orogen correlates well with a mid-crustal low velocity zone（LVZ）;（3） at depths deeper than 40 km, V（sh）〉V（sv） is still found in the Songpan-Ganzi terrane. This anisotropy could be caused by the sub-horizontal alignment of anisotropic minerals that has followed the collision between India and Eurasia. However, the northwestern Qilian orogen is associated with V（sv）〉V（sh） anisotropy which may be related to the vertically aligned seismic anisotropic minerals caused by the crustal thickening.
This article proves the nonexistence of global solutions to a semilinear wave equation on an exterior domain in
which is a part of Strauss’ conjecture.
The northeastern Tibetan Plateau has undergone active shortening due to the India‐Asia collision and has been an ideal place for studying the growth of the plateau. To reveal deep structure that is ...responsible for geological observations in NE Tibet, we have constructed a 3‐D shear wave velocity model from Rayleigh waves recorded by 36 stations in the Northeast Tibetan Plateau Seismic experiment. First, the two‐plane‐wave tomography method was applied to compute the average and 2‐D variations of phase velocities in a period range of 20 to 100 s. Then 1‐D and 3‐D shear wave velocity models were developed from the obtained Rayleigh wave dispersions. The entire region is characterized by a weak upper mantle with a relatively thin lithosphere of ~80–100 km thick. This observation helps to explain the active deformation at the Kunlun Mountains and the Qinling Orogen in NE Tibet. Relative low velocity anomalies appear along and to the south of the Kunlun fault (KF) in contrast to high velocity anomalies in the north and northeast. One pronounced slow anomaly centered at ~120 km depth is imaged right beneath the restraining bend of the Kunlun fault, which might be a northern extension of the large‐scale slow anomaly to the south of the fault. We interpret it as a local feature due to its large magnitude and coincidence with the restraining bend. It is probably related to anomalously high temperature and associated partial melting resulted from localized asthenosphere upwelling after the delamination of a thick lithosphere root. The formation of the thick lithosphere root would require coherent shortening in the crust and mantle lithosphere caused by local compression due to the bend of the strike‐slip fault, indicating that the Kunlun fault is probably on lithosphere scale and has played an important role in accommodating the eastward extrusion of the Tibetan Plateau.
Key Points
1‐D and 3‐D S wave velocity models to 150 km depth were constructed in NE Tibet
A low velocity anomaly is imaged at ~120 km depth beneath the Kunlun fault
These velocity models reveal the lower crust and upper mantle structure
In this paper, a nontrivial solution u∈H1(RN) to the autonomous Choquard equation with a local term −Δu+λu=(Iα∗|u|p)|u|p−2u+|u|q−2uinRNis obtained, where N≥3, α∈(0,N), λ>0 is a constant, Iα is the ...Riesz potential, N+αN<p<N+αN−2 and q∈(2,2∗=2NN−2). Under some further assumptions on p and q, the regularity and the Pohožaev identity of the solution are established, and then it is shown that the obtained solution is a groundstate of mountain pass type. Moreover, the positivity and symmetry of the groundstate are also considered. By using the results obtained for the autonomous equation, a positive groundstate solution for the nonautonomous equation −Δu+V(x)u=(Iα∗|u|p)|u|p−2u+|u|q−2uinRNis also found under some assumptions on V(x).
The aim of this study was to assess the effects of different thermal treatment temperatures on volatile compounds, lipid oxidation, and the Maillard reaction in water-boiled salted duck. A total of ...38 flavour compounds were detected, mainly including aldehydes, ketones, alcohols, esters, and furans. The contents of aldehydes, ketones, and furans in duck were significantly increased, while the contents of some alcohols and esters were decreased after high-temperature, high-pressure sterilisation (121 °C, 20 min). Low-temperature heat treatment (85 °C, 50 min; 95 °C, 40 min) had relatively little effect on the flavour of water-boiled salted duck. Thermal treatment significantly promoted the oxidative decomposition of unsaturated fatty acids. Monounsaturated fatty acids may play a key role in the formation of aldehydes and ketones. The Maillard browning was low, and the increase therein remained small after thermal treatment. The study showed that low-temperature heat treatment could better control changes in flavour.
•The effect of thermal treatment temperatures on the flavour of water-boiled salted duck after packaging was studied.•The thermal treatment temperatures had an impact on the flavour and lipid oxidation of the packaged meat products.•GC-IMS was used to detect volatile compounds in meat products.•95 °C thermal treatment was more suitable for the secondary sterilisation of packaged water-boiled salted ducks.
Micro-expressions (MEs) are natural facial mechanisms with short duration and subtle changes. It has attracted much attention in the real world due to its accuracy and uncontrollability of mental ...expression. With the development of computer vision, micro-expression Recognition (MER) methods have been continuously proposed and improved by scholars. However, the existing MER methods still have some deficiencies in processing Spatio-temporal redundant information and feature extraction. This paper proposes an MER network based on Differential Feature Fusion (DFF) method to solve this problem. First, inputs the onset frame and apex frame of the face, divide each image into small blocks, and uses part of the SE-ResNet50 model for feature extraction. Second, the Spatio-Temporal information of the features is extracted by using a DFF module composed of a differential feature module, CapsuleNet, and a Fully Connected (FC) layer. Finally, inputs the feature vector to the FC module for classification. This study is based on the Leave One Subject Out (LOSO) cross-validation protocol and uses the CASMEII dataset. Experiments and comparisons show the effectiveness of the algorithm.
•A thin and flat LAB is observed in Central Eastern China, suggesting uniform destruction.•We attribute the destruction to lithospheric delamination along a mid-lithospheric discontinuity.•After the ...destruction, slab rollback and trench retreat further stretched the lithosphere.
Detailed knowledge of the lithospheric thickness is important for understanding the tectonic evolution in central Eastern China, characterized by ore deposits in the Middle-Lower Yangtze Metallogenic Belt (MLYMB). We realize this goal by applying the common conversion point (CCP) stacking to Sp receiver functions (SRF) computed from 234 broadband seismic stations in central Eastern China. Distinct negative signals are identified below the Moho in all the CCP stacking profiles, which we interpret as the S-to-P conversions from the lithosphere-asthenosphere boundary (LAB). The imaged LAB is as shallow as ∼60 km with a standard deviation of ∼5 km in the whole region, in contrast to the typical cratonic lithosphere root down to 200 km depth or more, indicating the widespread lithospheric thinning in the study region. Such a flat LAB indicates that the regional lithosphere has been destructed uniformly, shedding light on its destructive mechanism, which we attribute to lithospheric delamination along a mid-lithospheric discontinuity (MLD). Compared to the MLD (∼80–100 km) observed in the western North China Craton, our observations suggest that the destructed lithosphere probably has been further stretched due to slab rollback and trench retreat. In contrast, lithospheric cooling-induced accretion plays a minor role in the lithospheric evolution after destruction.
Pulsed electric field (PEF), as an emerging nonthermal processing technology, has attracted extensive attention and research in food processing. In the present study, PEF has been approved that has ...the potential to enhance salt diffusion in pork. In this study, pork lions were pretreated with PEF before being immersed in the brine (5% NaCl w/w) at 4°C to investigate the effect of needle–needle PEF pretreatment on pork brine salting. The changes in the weight, moisture, and salt content were detected during the salting process. The effective diffusion coefficient (De) and mass transfer kinetics were calculated. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were subsequently used to analyze the microstructure of the pork and the secondary structure of myofibrillar proteins (MPs). The outcomes demonstrated that after brining for 8 h with PEF pretreatment, the weight, moisture, and salt changes increased significantly. The central salt content achieved by 12 h brining after PEF treatment (4.5 kV) is equivalent to that achieved by brining for 20 h without any treatment. The De was raised to 4.0 × 10−10 (PEF) from 3.1 × 10−10 (control). SEM and FTIR results revealed that PEF altered the microstructure of pork and the secondary structure of MP. Our study demonstrated that PEF generated by needle–needle electrodes could effectively promote salt diffusion and shorten salting processing.
The Deleted in Azoospermia (DAZ) genes encode potential RNA-binding proteins that are expressed exclusively in the germ-line. The bovine Deleted in Azoospermia-like gene is a strong candidate for ...male cattle-yak infertility. In this work, with the goe goal to further reveal the genetic cause of male cattle-yak sterility, another bovine DAZ family gene, b-boule, was isolated and characterized. The b-boule gene is predicted to encode a polypeptide of 295 amino acids with an RNP-type RNA recognition domain. Tertiary structure analysis shows that b-boule binds specifically to polypyrimidine RNAs and might act as a nuclear ribonucleoprotein particle auxiliary factor during germ cell formation and morphological changes of germ cells. RT-PCR assays revealed that b-boule was expressed specifically in the adult testis. However, an extremely low level of expression was detected in the testis of sterile male cattle-yaks. Microstructure of the testes from sterile males showed that type A spermatogonia were the only germ cells present and that few germ cells developed further than the stage of pachytene spermatocytes. These results suggest that b-boule may function in bovine spermatogenesis, and that low levels of b-boule expression might lead to male sterility in cattle-yaks.
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