2,245 research outputs found
Geometric effects of a quarter of corrugated torus
In the spirit of the thin-layer quantization scheme, we give the effective
Shr\"{o}dinger equation for a particle confined to a corrugated torus, in which
the geometric potential is substantially changed by corrugation. We find the
attractive wells reconstructed by the corrugation not being at identical
depths, which is strikingly different from that of a corrugated nanotube,
especially in the inner side of the torus. By numerically calculating the
transmission probability, we find that the resonant tunneling peaks and the
transmission gaps are merged and broadened by the corrugation of the inner side
of torus. These results show that the quarter corrugated torus can be used not
only to connect two tubes with different radiuses in different directions, but
also to filter the particles with particular incident~energies.Comment: 7 pages, 8 figure
Metasomatized lithospheric mantle for Mesozoic giant gold deposits in the North China craton
The origin of giant lode gold deposits of Mesozoic age in the North China craton (NCC) is enigmatic because high-grade metamorphic ancient crust would be highly depleted in gold. Instead, lithospheric mantle beneath the crust is the likely source of the gold, which may have been anomalously enriched by metasomatic processes. However, the role of gold enrichment and metasomatism in the lithospheric mantle remains unclear. Here, we present comprehensive data on gold and platinum group element contents of mantle xenoliths (n = 28) and basalts (n = 47) representing the temporal evolution of the eastern NCC. The results indicate that extensive mantle metasomatism and hydration introduced some gold (<1–2 ppb) but did not lead to a gold-enriched mantle. However, volatile-rich basalts formed mainly from the metasomatized lithospheric mantle display noticeably elevated gold contents as compared to those from the asthenosphere. Combined with the significant inheritance of mantle-derived volatiles in auriferous fluids of ore bodies, the new data reveal that the mechanism for the formation of the lode gold deposits was related to the volatile-rich components that accumulated during metasomatism and facilitated the release of gold during extensional craton destruction and mantle melting. Gold-bearing, hydrous magmas ascended rapidly along translithospheric fault zones and evolved auriferous fluids to form the giant deposits in the crust
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Optical biopsy identification and grading of gliomas using label-free visible resonance Raman spectroscopy.
Glioma is one of the most refractory types of brain tumor. Accurate tumor boundary identification and complete resection of the tumor are essential for glioma removal during brain surgery. We present a method based on visible resonance Raman (VRR) spectroscopy to identify glioma margins and grades. A set of diagnostic spectral biomarkers features are presented based on tissue composition changes revealed by VRR. The Raman spectra include molecular vibrational fingerprints of carotenoids, tryptophan, amide I/II/III, proteins, and lipids. These basic in situ spectral biomarkers are used to identify the tissue from the interface between brain cancer and normal tissue and to evaluate glioma grades. The VRR spectra are also analyzed using principal component analysis for dimension reduction and feature detection and support vector machine for classification. The cross-validated sensitivity, specificity, and accuracy are found to be 100%, 96.3%, and 99.6% to distinguish glioma tissues from normal brain tissues, respectively. The area under the receiver operating characteristic curve for the classification is about 1.0. The accuracies to distinguish normal, low grade (grades I and II), and high grade (grades III and IV) gliomas are found to be 96.3%, 53.7%, and 84.1% for the three groups, respectively, along with a total accuracy of 75.1%. A set of criteria for differentiating normal human brain tissues from normal control tissues is proposed and used to identify brain cancer margins, yielding a diagnostic sensitivity of 100% and specificity of 71%. Our study demonstrates the potential of VRR as a label-free optical molecular histopathology method used for in situ boundary line judgment for brain surgery in the margins
Pharmacokinetics and safety of repirinast tablets in healthy Chinese subjects
Repirinast is a new, synthetic, disodium cromoglycate-like antiallergic agent for oral administration in humans. This study evaluated the safety, tolerability and pharmacokinetics of repirinast tablets in healthy Chinese volunteers. This was a phase I, open-label, randomized, single- and multiple-dose study. Subjects were assigned to receive a single dose of repirinast tablet at either 150, 300, or 450 mg, or multiple doses of 150 mg twice daily for 5 days. Plasma samples were analyzed with LC-MS/MS. Pharmacokinetic parameters of active metabolite MY-1250 (deesterified repirinast) were calculated using non-compartmental analysis with WinNonlin software. Statistical analysis was performed using SPSS software. All adverse events (AEs) were mild and of limited duration. No serious adverse event (SAE), death or withdrawal from the study was observed. In the single-dose study, Cmax was reached at about 0.75 hour, and the mean t1/2 was approximately 16.21 hours. Area under curve (AUC) and Cmax increased with dose escalation, but dose proportionality was not observed over the range of 150 to 450 mg. In the multiple-dose study, the steady-state was reached within 3 days with no accumulation. Repirinast tablet was well tolerated in healthy Chinese subjects
3-tert-Butyl-2-oxo-1-oxaspiro[4.5]dec-3-en-4-yl 4-chlorobenzoate
The title tetronic acid derivative, C20H23ClO4, which is a spirodiclofen analogue, has two crystallographically independent molecules in the asymmetric unit (Z′ = 2). The cyclohexane rings in the respective molecules A and B adopt chair conformations [four C atoms are planar with mean deviations of 0.013 (2) and 0.001 (2) Å, and the flap positions deviate by 0.653 (4) and −0.663 (3) Å (molecule A) and 0.642 (4) and −0.643 (5) Å (molecule B) from the plane]. The furan ring makes dihedral angles of 86.9 (1) (molecule A) and 85.4 (1)° (molecule B) with the respective benzene rings
Emotion-Aware Contrastive Adaptation Network for Source-Free Cross-Corpus Speech Emotion Recognition
Cross-corpus speech emotion recognition (SER) aims to transfer emotional
knowledge from a labeled source corpus to an unlabeled corpus. However, prior
methods require access to source data during adaptation, which is unattainable
in real-life scenarios due to data privacy protection concerns. This paper
tackles a more practical task, namely source-free cross-corpus SER, where a
pre-trained source model is adapted to the target domain without access to
source data. To address the problem, we propose a novel method called
emotion-aware contrastive adaptation network (ECAN). The core idea is to
capture local neighborhood information between samples while considering the
global class-level adaptation. Specifically, we propose a nearest neighbor
contrastive learning to promote local emotion consistency among features of
highly similar samples. Furthermore, relying solely on nearest neighborhoods
may lead to ambiguous boundaries between clusters. Thus, we incorporate
supervised contrastive learning to encourage greater separation between
clusters representing different emotions, thereby facilitating improved
class-level adaptation. Extensive experiments indicate that our proposed ECAN
significantly outperforms state-of-the-art methods under the source-free
cross-corpus SER setting on several speech emotion corpora.Comment: Accepted by ICASSP 202
Search for heavy Majorana neutrinos at future lepton colliders
The nonzero neutrino mass can be a signal for new physics beyond the standard
model. To explain the tiny neutrino mass, we can extend the standard model with
right-handed Majorana neutrinos in a low-scale seesaw mechanism, while the CP
violation effect can be induced due to the CP phase in the interference of
heavy Majorana neutrinos. The existence of heavy Majorana neutrinos may lead to
lepton number violation processes, which can be used as a probe to search for
the signal of heavy Majorana neutrinos. In this paper, we focus on the CP
violation effect related to two generations of heavy Majorana neutrinos for
GeV GeV in the pair production of W bosons and rare decays.
It is valuable to investigate the Majorana neutrino production signals and the
related CP violation effects in the W boson rare decays at future lepton
colliders.Comment: 12 pages, 8 figure
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