1,391 research outputs found
Two new species of the genus Bothropolys Wood, 1862 (Chilopoda: Lithobiomorpha: Lithobiidae) from China
The present paper deals with two new species of the genus Bothropolys Wood, 1862 (Lithobiomorpha: Lithobiidae), recently discovered in China. Bothropolys stoevi sp. n. was found in Hebei and Shanxi Provinces, and Bothropolys edgecombei sp. n.was found in Sichuan Province.We present a key and distributional map of the Chinese Bothropolys species
Second-order Band Topology in Antiferromagnetic (MnBiTe)(BiTe) Films
The existence of fractionally quantized topological corner states serves as a
key indicator for two-dimensional second-order topological insulators (SOTIs),
yet has not been experimentally observed in realistic materials. Here, based on
first-principles calculations and symmetry arguments, we propose a strategy for
achieving SOTI phases with in-gap corner states in
(MnBiTe)(BiTe) films with antiferromagnetic (AFM) order.
Starting from the prototypical AFM MnBiTe bilayer, we show by an
effective lattice model that such SOTI phase originate from the interplay
between intrinsic spin-orbital coupling and interlayer AFM exchange
interactions. Furthermore, we demonstrate that the nontrivial corner states are
linked to rotation topological invariants under three-fold rotation symmetry
, resulting in -symmetric SOTIs with corner charges fractionally
quantized to (mod ). Due to the great recent
achievements in (MnBiTe)(BiTe) systems, our results
providing reliable material candidates for experimentally accessible AFM
higher-order band topology would draw intense attentions.Comment: 6 pages, 4 figure
Australobius polyspinipes sp. n., a new species of Australobius Chamberlin, 1920 (Lithobiomorpha: Lithobiidae) from China
Australobius polyspinipes sp. n. (Lithobiomorpha: Lithobiidae) was recently discovered from Tianheshan Mountain, Hebei Province, China, and it is described here. Morphologically the new species is similar to A. nodulus Ma, Song &Zhu, 2008 and A. magnus (Trozina, 1894), both recorded from China. The new species can be easily distinguished from those by having 7+7–8+8 coxosternal teeth, 10–12 ocelli on each side of the cephalic plate, 5+5 spurs on the first article of the female gonopods and differences in plectrotaxy of legs. The main morphological characters and a key to the known Chinese species of genus Australobius based on adult specimens is presented
Learning List-Level Domain-Invariant Representations for Ranking
Domain adaptation aims to transfer the knowledge learned on (data-rich)
source domains to (low-resource) target domains, and a popular method is
invariant representation learning, which matches and aligns the data
distributions on the feature space. Although this method is studied extensively
and applied on classification and regression problems, its adoption on ranking
problems is sporadic, and the few existing implementations lack theoretical
justifications. This paper revisits invariant representation learning for
ranking. Upon reviewing prior work, we found that they implement what we call
item-level alignment, which aligns the distributions of the items being ranked
from all lists in aggregate but ignores their list structure. However, the list
structure should be leveraged, because it is intrinsic to ranking problems
where the data and the metrics are defined and computed on lists, not the items
by themselves. To close this discrepancy, we propose list-level alignment --
learning domain-invariant representations at the higher level of lists. The
benefits are twofold: it leads to the first domain adaptation generalization
bound for ranking, in turn providing theoretical support for the proposed
method, and it achieves better empirical transfer performance for unsupervised
domain adaptation on ranking tasks, including passage reranking.Comment: NeurIPS 2023. Comparison to v1: revised presentation and proof of
Corollary 4.
Decomposition and Decoupling Analysis of Carbon Emissions in Xinjiang Energy Base, China
China faces a difficult choice of maintaining socioeconomic development and carbon emissions mitigation. Analyzing the decoupling relationship between economic development and carbon emissions and its driving factors from a regional perspective is the key for the Chinese government to achieve the 2030 emission reduction target. This study adopted the logarithmic mean Divisia index (LMDI) method and Tapio index, decomposed the driving forces of the decoupling, and measured the sector’s decoupling states from carbon emissions in Xinjiang province, China. The results found that: (1) Xinjiang’s carbon emissions increased from 93.34 Mt in 2000 to 468.12 Mt in 2017. Energy-intensive industries were the key body of carbon emissions in Xinjiang. (2) The economic activity effect played the decisive factor to carbon emissions increase, which account for 93.58%, 81.51%, and 58.62% in Xinjiang during 2000–2005, 2005–2010, and 2010–2017, respectively. The energy intensity effect proved the dominant influence for carbon emissions mitigation, which accounted for −22.39% of carbon emissions increase during 2000–2010. (3) Weak decoupling (WD), expansive coupling (EC), expansive negative decoupling (END) and strong negative decoupling (SND) were identified in Xinjiang during 2001 to 2017. Gross domestic product (GDP) per capita elasticity has a major inhibitory effect on the carbon emissions decoupling. Energy intensity elasticity played a major driver to the decoupling in Xinjiang. Most industries have not reached the decoupling state in Xinjiang. Fuel processing, power generation, chemicals, non-ferrous, iron and steel industries mainly shown states of END and EC. On this basis, it is suggested that local governments should adjust the industrial structure, optimize energy consumption structure, and promote energy conservation and emission reduction to tap the potential of carbon emissions mitigation in key sectors
Annual evolution of the ice–ocean interaction beneath landfast ice in Prydz Bay, East Antarctica
High-frequency observations of the ice–ocean interaction and high-precision estimation of the ice–ocean heat exchange are critical
to understanding the thermodynamics of the landfast ice mass balance in
Antarctica. To investigate the oceanic contribution to the evolution of the
landfast ice, an integrated ocean observation system, including an acoustic
Doppler velocimeter (ADV), conductivity–temperature–depth (CTD) sensors,
and a sea ice mass balance array (SIMBA), was deployed on the landfast ice
near the Chinese Zhongshan Station in Prydz Bay, East Antarctica, from April to November 2021. The CTD sensors recorded the ocean temperature and salinity.
The ocean temperature experienced a rapid increase in late April, from
−1.62 to the maximum of −1.30 ∘C, and then it gradually decreased to −1.75 ∘C in May and remained at this
temperature until November. The seawater salinity and density exhibited
similar increasing trends during April and May, with mean rates of 0.04 psu d−1 and 0.03 kg m−3 d−1, respectively, which was related
to the strong salt rejection caused by freezing of the landfast ice. The
ocean current observed by the ADV had mean horizontal and vertical
velocities of 9.5 ± 3.9 and 0.2 ± 0.8 cm s−1,
respectively. The domain current direction was ESE (120∘)–WSW
(240∘), and the domain velocity (79 %) was 5–15 cm s−1.
The oceanic heat flux (Fw) estimated using the residual method reached a
peak of 41.3 ± 9.8 W m−2 in April, and then it gradually decreased to a stable level of 7.8 ± 2.9 W m−2 from June to
October. The Fw values calculated using three different bulk
parameterizations exhibited similar trends with different magnitudes due to
the uncertainties of the empirical friction velocity. The spectral analysis
results suggest that all of the observed ocean variables exhibited a typical
half-day period, indicating the strong diurnal influence of the local tidal
oscillations. The large-scale sea ice distribution and ocean circulation
contributed to the seasonal variations in the ocean variables, revealing the
important relationship between the large-scale and local phenomena. The high-frequency and cross-seasonal observations of oceanic variables obtained in
this study allow us to deeply investigate their diurnal and seasonal
variations and to evaluate their influences on the landfast ice evolution.</p
Changes in axial length in anisometropic children wearing orthokeratology lenses
PurposeThere is a particular anisometropia occurring in one eye with myopia, while the other eye has very low myopia, emmetropia, or very low hyperopia. It is unclear how the binocular axial length changes when these children wear unilateral OK lenses only in the more myopic eyes. This study investigates the changes in the axial elongation of both eyes.MethodsThis is a 1-year retrospective study. In total, 148 children with myopic anisometropia were included. The more myopic eyes were wearing orthokeratology lenses (treated eyes), whereas the contralateral eyes were not indicated for visual correction (untreated eyes). The untreated eyes were classified into three subgroups based on the spherical equivalent refraction (SER): low myopia (≤ -0.50 D, n = 37), emmetropia (+0.49 to −0.49 D, n = 76), and low hyperopia (≥0.50 D, n = 35). Changes in the axial length (AL) were compared between the untreated and treated eyes and among the three subgroups.ResultsThe axial elongation was 0.14 ± 0.18 mm and 0.39 ± 0.27 mm in all treated and untreated eyes, respectively (p < 0.001). The interocular AL difference decreased significantly from 1.09 ± 0.45 mm at the baseline to 0.84 ± 0.52 mm at 1 year (p < 0.001). The baseline median (Q1, Q3) SER of the untreated eyes were −0.75 D (−0.56, −0.88 D), 0.00 D (0.00, −0.25 D), and +0.75 D (+1.00, +0.62 D) in low myopia, emmetropia, and low hyperopia subgroups, respectively. The axial elongation was 0.14 ± 0.18 mm, 0.15 ± 0.17 mm, and 0.13 ± 0.21 mm (p = 0.92) in the treated eyes and 0.44 ± 0.25 mm, 0.35 ± 0.24 mm, and 0.41 ± 0.33 mm in the untreated eyes (p = 0.11) after 1 year. Multivariate linear regression analyses only showed significant differences in axial elongation between the emmetropia and low myopia subgroups of untreated eyes (p = 0.04; p > 0.05 between other subgroups).ConclusionUnilateral orthokeratology lenses effectively reduced axial elongation in the more myopic eyes and reduced interocular AL differences in children with myopic anisometropia. The refractive state of the untreated eyes did not affect the axial elongation of the more myopic eye wearing the orthokeratology lens. In the untreated eyes, AL increased faster in the low myopia subgroup than in the emmetropia subgroup
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