2,529 research outputs found
Sensitive frequency-dependence of the carrier-envelope phase effect on bound-bound transition: an interference perspective
We investigate numerically with Hylleraas coordinates the frequency
dependence of the carrier-envelope phase (CEP) effect on bound-bound
transitions of helium induced by an ultrashort laser pulse of few cycles. We
find that the CEP effect is very sensitive to the carrier frequency of the
laser pulse, occurring regularly even at far-off resonance frequencies. By
analyzing a two-level model, we find that the CEP effect can be attributed to
the quantum interference between neighboring multi-photon transition pathways,
which is made possible by the broadened spectrum of the ultrashort laser pulse.
A general picture is developed along this line to understand the sensitivity of
the CEP effect to laser's carrier frequency. Multi-level influence on the CEP
effect is also discussed
A loss-of-function allele of OsHMA3 associated with high cadmium accumulation in shoots and grain of Japonica rice cultivars
This article is protected by copyright. All rights reserved.Peer reviewedPostprin
Variation of the Fine-Structure Constant from the de Sitter Invariant Special Relativity
There are obvious discrepancies among various experimental constraints on the
variation of the fine-structure constant, . We attempt to discuss the
issue in the framework of de Sitter invariant Special Relativity () and to present a possible solution to the disagreement. In
addition, on the basis of the observational data and the discussions presented
in this Letter, we derive a rough theoretical estimate of the radius of the
Universe.Comment: 8 pages, no figure
rac-3-{4-[(Furan-2-ylmethylidene)amino]-3-methyl-5-sulfanylidene-4,5-dihydro-1H-1,2,4-triazol-1-yl}-1,3-diphenylpropan-1-one
In the title molecule, C23H20N4O2S, the triazole ring forms dihedral angles of 150.3 (2), 77.3 (2) and 77.6 (2)°, respectively, with the furan ring and the phenyl rings. The furan ring is almost perpendicular to the central phenyl ring, making a dihedral angle of 86.0 (3)°
对乙酰氨基酚中毒1例的抢救治疗和护理
Acetaminophen is commonly used for fever, joint pain, neuralgia, and migraine for its antipyretic and analgesic effects in clinical practice. While large dose of acetaminophen may result in toxic, which causes coma and respiratory failure, cardiac arrest and other organ damage. The paper discusses nursing methods of condition monitoring during continuous blood purification treatment, prevention of infection and nutritional support in patients with acetaminophen poisoning by case analysis.对乙酰胺基酚是临床常用的解热镇痛药,常用于发热、关节痛、神经痛和偏头痛的治疗,大剂量对乙酰胺基酚口服可引起中毒,导致昏迷、呼吸衰竭、心脏骤停等器官的损害。本文通过病例分析,探讨对乙酰氨基酚中毒患者行连续性血液净化治疗期间病情监测、预防感染、营养支持等护理方法
Standardized Volume Power Density Boost in Frequency-Up Converted Contact-Separation Mode Triboelectric Nanogenerators
The influence of a mechanical structure’s volume increment on the volume power density (VPD) of triboelectric nanogenerators (TENGs) is often neglected when considering surface charge density and surface power density. This paper aims to address this gap by introducing a standardized VPD metric for a more comprehensive evaluation of TENG performance. The study specifically focuses on 2 frequency-up mechanisms, namely, the integration of planetary gears (PG-TENG) and the implementation of a double-cantilever structure (DC-TENG), to investigate their impact on VPD. The study reveals that the PG-TENG achieves the highest volume average power density, measuring at 0.92 W/m3. This value surpasses the DC-TENG by 1.26 times and the counterpart TENG by a magnitude of 69.9 times. Additionally, the PG-TENG demonstrates superior average power output. These findings introduce a new approach for enhancing TENGs by incorporating frequency-up mechanisms, and highlight the importance of VPD as a key performance metric for evaluating TENGs
2-[(3-Propylsulfanyl-5-p-tolyl-4H-1,2,4-triazol-4-yl)iminomethyl]phenol
In the title molecule, C19H20N4OS, the two benzene rings form dihedral angles of 16.2 (1) and 12.0 (1)°, respectively, with the central triazole ring. In the crystal, intermolecular O—H⋯N hydrogen bonds link molecules into chains in the [010] direction
In Vitro and In Vivo Study
Nanofibers have attracted increasing attention in drug delivery and other
biomedical applications due to their some special properties. The present
study aims to prepare a fiber-based nanosolid dispersion system to enhance the
bioavailability of curcumin (CUR). CUR-loaded polyvinyl pyrrolidone (CUR@PVP)
nanofibers were successfully prepared via electrospinning. Scanning electron
microscopy (SEM) was employed to observe the morphology of the nanofibers, and
the SEM image showed that the drug-loaded nanofibers were smooth, and no CUR
clusters were found on the surface of the nanofibers. The results of X-ray
diffraction (XRD) demonstrated that the CUR was evenly distributed in the
nanofibers in an amorphous state. Fourier transform infrared (FTIR)
spectroscopy analysis indicated that intermolecular hydrogen bonding occurred
between the CUR and the polymer matrix. In vitro dissolution profiles showed
that CUR@PVP nanofiber could be quickly dissolved in phosphate-buffered saline
(PBS) solution, while negligible dissolution was observed in pure CUR sample.
Importantly, in vitro cell viability assays and in vivo animal tests revealed
that the nanosolid dispersion system dramatically enhanced the bioavailability
and showed effective anticancer effect of the CUR
Maps of cropping patterns in China during 2015–2021
Multiple cropping is a widespread approach for intensifying crop production through rotations of diverse crops. Maps of cropping intensity with crop descriptions are important for supporting sustainable agricultural management. As the most populated country, China ranked first in global cereal production and the percentages of multiple-cropped land are twice of the global average. However, there are no reliable updated national-scale maps of cropping patterns in China. Here we present the first recent annual 500-m MODIS-based national maps of multiple cropping systems in China using phenologybased mapping algorithms with pixel purity-based thresholds, which provide information on cropping intensity with descriptions of three staple crops (maize, paddy rice, and wheat). The produced cropping patterns maps achieved an overall accuracy of 89% based on ground truth data, and a good agreement with the statistical data (R2 ≥ 0.89). The China Cropping Pattern maps (ChinaCP) are available for public download online. Cropping patterns maps in China and other countries with finer resolutions can be produced based on Sentinel-2 Multispectral Instrument (MSI) images using the shared code
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