211 research outputs found

    Composite Biased Rotations for Precise Raman Control of Spinor Matterwaves

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    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

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    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]

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    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

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    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, Pbx_xSr1x_{1-x}TiO3_3 and Hfx_xZr1x_{1-x}O2_2. 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 Pbx_xSr1x_{1-x}TiO3_3 reproduces a few known topological textures such as polar vortex lattice and electric dipole waves in PbTiO3_3/SrTiO3_3 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

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    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

    Context-aware Coherent Speaking Style Prediction with Hierarchical Transformers for Audiobook Speech Synthesis

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    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

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    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

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    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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