211 research outputs found
Composite Biased Rotations for Precise Raman Control of Spinor Matterwaves
Precise control of hyperfine matterwaves via Raman excitations is
instrumental to a class of atom-based quantum technology. We investigate the
Raman spinor control technique for alkaline atoms in an intermediate regime of
single-photon detuning where a choice can be made to balance the Raman
excitation power efficiency with the control speed, excited-state adiabatic
elimination, and spontaneous emission suppression requirements. Within the
regime, rotations of atomic spinors by the Raman coupling are biased by
substantial light shifts. Taking advantage of the fixed bias angle, we show
that composite biased rotations can be optimized to enable precise ensemble
spinor matterwave control within nanoseconds, even for multiple Zeeman
pseudo-spins defined on the hyperfine ground states and when the laser
illumination is strongly inhomogeneous. Our scheme fills a technical gap in
light pulse atom interferometry, for achieving high speed Raman spinor
matterwave control with moderate laser power.Comment: 11 pages, 6 figure
Positive Self-Compassion, Self-Coldness, and Psychological Outcomes in College Students:a Person-Centered Approach
Objectives Self-compassion is related to psychological outcomes. By examining wholistic concept of self-compassion, previous research has overlooked the possibility that people may differ in combination of positive self-compassion and self-coldness. This study, using a person-centered approach, aimed to identify subgroups of college students based on different profiles of positive self-compassion and self-coldness. We also examined how these profiles related to socio-demographic variables as well as psychological outcomes. Methods This cross-sectional study included 1029 Chinese college students. Self-reported questionnaires were used to collect levels of positive self-compassion and self-coldness (including six facets) and psychological outcomes (depressive symptoms, anxiety symptoms, negative affect, and positive affect). A latent profile analysis was performed to identify different profiles based on the six facets. The Bolck-Croon-Hagenaars approach was used to examine how profiles related to socio-demographic variables and psychological outcomes. Results Five distinct profiles were identified: high self-coldness, low self-compassion (16.2%), high self-compassion, low self-coldness (17.2%), average self-compassion, average self-coldness (38.9%), low self-compassion, low self-coldness (17.5%), and high self-compassion, high self-coldness (10.2%). Older people tended to report high self-compassion, high self-coldness profile, and females tended to have high self-coldness, low self-compassion profile. People with high self-compassion, low self-coldness profile reported the best psychological outcomes, whereas those in high self-coldness, low self-compassion and high self-compassion, high self-coldness profiles experienced the worst outcomes. Conclusions We identified five subgroups with different combinations of the six facets of self-compassion and self-coldness. People with distinct profiles differed on psychological outcomes. Future research is needed to adopt longitudinal design and replicate our findings in different groups
Poly[[chloridodimethanol(μ3-pyridine-2,3-dicarboxylato)europium(III)] methanol monosolvate]
The asymmetric unit of the title compound, {[Eu(C7H3NO4)Cl(CH3OH)2]·CH3OH}n, contains one EuIII ion, one pyridine 2,3-dicarboxylate dianion (PDC), two CH3OH molecules coordinating to the metal atom, one coordinating chloride and one lattice occluded CH3OH molecule. In the crystal, each PDC anion coordinates to three adjacent EuIII ions by the pyridine N and O atoms of the carboxylate groups. The EuIII cation is eightfold coordinated by four carboxylate O atoms, one pyridine N atom, two MeOH and one chloride anion in the form of a distorted polyhedron. Extended coordination of the PDC ligand lead to the formation of a two-dimensional coordination polymer parallel to (10-1)
Modular development of deep potential for complex solid solutions
The multicomponent oxide solid solution is a versatile platform to tune the
delicate balance between competing spin, charge, orbital, and lattice degrees
of freedom for materials design and discovery. The development of
compositionally complex oxides with superior functional properties has been
largely empirical and serendipitous, in part due to the exceedingly complex
chemistry and structure of solid solutions that span a range of length scales.
The classical molecular dynamics (MD), as a powerful statistical method to
investigate materials properties over large spatial and temporal scales, often
plays a secondary role in computer-aided materials discovery because of the
limited availability and accuracy of classical force fields. Here, we introduce
the strategy of ``modular developing deep potential" (ModDP) that enables a
systematic development and improvement of deep neural network-based model
potential, termed as deep potential, for complex solid solutions with minimum
human intervention. The converged training database associated with an
end-member material is treated as an independent module and is reused to train
the deep potential of solid solutions via a concurrent learning procedure. We
apply ModDP to obtain classical force fields of two technologically important
solid solutions, PbSrTiO and HfZrO. For both
materials systems, a single model potential is capable of predicting various
properties of solid solutions including temperature-driven and
composition-driven phase transitions over a wide range of compositions. In
particular, the deep potential of PbSrTiO reproduces a few
known topological textures such as polar vortex lattice and electric dipole
waves in PbTiO/SrTiO superlattices, paving the way for MD
investigations on the dynamics of topological structures in response to
external stimuli.Comment: 32 pages, 9 figure
Novel Microfiber Sensor and Its Biosensing Application for Detection of hCG Based on a Singlemode-Tapered Hollow Core-Singlemode Fiber Structure
A novel microfiber sensor is proposed and demonstrated based on a singlemode-tapered hollow core -singlemode (STHS) fiber structure. Experimentally a STHS with taper waist diameter of 26.5 μm has been fabricated and RI sensitivity of 816, 1601.86, and 4775.5 nm/RIU has been achieved with RI ranges from 1.3335 to 1.3395 , from 1.369 to 1.378, and from 1.409 to 1.4175 respectively, which agrees very well with simulated RI sensitivity of 885, 1517, and 4540 nm/RIU at RI ranges from 1.3335 to 1.337, from 1.37 to 1.374, and from 1.41 to 1.414 . The taper waist diameter has impact on both temperature and strain sensitivity of the sensor structure: (1) the smaller the waist diameter, the higher the temperature sensitivity, and experimentally 26.82 pm/°C has been achieved with a taper waist diameter of 21.4 μm; (2) as waist diameter decrease, strain sensitivity increase and 7.62 pm/με has been achieved with a taper diameter of 20.3 μm. The developed sensor was then functionalized for human chorionic gonadotropin (hCG) detection as an example for biosensing application. Experimentally for hCG concentration of 5 mIU/ml, the sensor has 0.5 nm wavelength shift, equivalent to limit of detection (LOD) of 0.6 mIU/ml by defining 3 times of the wavelength variation (0.06 nm) as measurement limit. The biosensor demonstrated relatively good reproducibility and specificity, which has potential for real medical diagnostics and other applications
2021 China Business Survey:On Business Performance and Adjustments of Companies in China during the COVID-19 Period
Context-aware Coherent Speaking Style Prediction with Hierarchical Transformers for Audiobook Speech Synthesis
Recent advances in text-to-speech have significantly improved the
expressiveness of synthesized speech. However, it is still challenging to
generate speech with contextually appropriate and coherent speaking style for
multi-sentence text in audiobooks. In this paper, we propose a context-aware
coherent speaking style prediction method for audiobook speech synthesis. To
predict the style embedding of the current utterance, a hierarchical
transformer-based context-aware style predictor with a mixture attention mask
is designed, considering both text-side context information and speech-side
style information of previous speeches. Based on this, we can generate
long-form speech with coherent style and prosody sentence by sentence.
Objective and subjective evaluations on a Mandarin audiobook dataset
demonstrate that our proposed model can generate speech with more expressive
and coherent speaking style than baselines, for both single-sentence and
multi-sentence test.Comment: Accepted by ICASSP 202
Spatial variability in the abundance, composition, and age of organic matter in surficial sediments of the East China Sea
Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Biogeosciences 118 (2013): 1495–1507, doi:10.1002/2013JG002286.Understanding the sources and fate of organic matter (OM) sequestered in continental margin sediments is of importance because the mode and efficiency of OM burial impact the carbon cycle and the regulation of atmospheric CO2 over long time scales. We carried out molecular (lignin-derived phenols from CuO oxidation), elemental, isotopic (δ13C, Δ14C), and sedimentological (grain size and mineral surface area) analyses in order to examine spatial variability in the abundance, source, age of surface sediments of the East China Sea. Higher terrigenous organic matter values were found in the main accumulating areas of fluvial sediments, including the Changjiang (Yangtze) Estuary and Zhejiang-Fujian coastal zone. Isotopic and biomarker data suggest that the sedimentary OM in the inner shelf region was dominated by aged (Δ14C = −423 ± 42‰) but relatively lignin-rich OM (Λ = 0.94 ± 0.57 mg/100 mg OC) associated with fine-grained sediments, suggesting important contributions from soils. In contrast, samples from the outer shelf, while of similar age (Δ14 C = −450 ± 99‰), are lignin poor (Λ = 0.25 ± 0.14 mg/100 mg OC) and associated with coarse-grained material. Regional variation of lignin phenols and OM ages indicates that OM content is fundamentally controlled by hydrodynamic sorting (especially, sediment redistribution and winnowing) and in situ primary production. Selective sorption of acid to aldehyde in clay fraction also modified the ratios of lignin phenols. The burial of lignin in East China Sea is estimated to be relatively efficient, possibly as a consequence of terrigenous OM recalcitrance and/or relatively high sedimentation rates in the Changjiang Estuary and the adjacent Zhejing-Fujian mud belt.This study was funded by the Natural Science
Foundation of China (41021064), Ministry of Science and Technology
(2011CB409802), and others such as (41076052, 2010DFA24590). WY acknowledges
financial support from the Alexander von Humboldt Foundation
and SKLCE RCD and 111 projects. TE acknowledges financial support from
a WHOI Senior Scientist Chair.2014-05-1
Nitrous oxide research progress in polar and sub-polar oceans
N2O gas depletes ozone and has a powerful greenhouse effect. Oceans are among the most important N2O sources and have been the subject of extensive studies. Polar oceans are important regions for deep water formation and global-scale thermohaline circulation. Therefore, these water bodies play an important role in the N2O budget, however, these regions were not well studied. This review of previously published studies and data on polar oceans, including both the Arctic Ocean and Southern Ocean, describes the distribution pattern of N2O and possible regulating mechanism of these distribution patterns and shows that the Arctic Ocean and Southern Ocean both represent source and sink regions, suggesting that the source/sink characteristics of the Arctic and Southern oceans and their strengths need further study. Questions related to N2O circulation in polar oceans were proposed, and future work is suggested
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