270 research outputs found
Transport discovery of emerging robust helical surface states in systems
We study the possibility of realizing robust helical surface states in
systems. We find that the combination of anisotropy and finite-size
confinement leads to the emergence of robust helical edge states in both 2D and
3D systems. By investigating an anisotropic Bernevig-Hughes-Zhang model
in a finite sample, we demonstrate that the transport manifestation of the
surface states is robust against non-magnetic disorder, resembling that of a
phase. Notably, the effective energy gap for the robust helical
states can be efficiently engineered, allowing for potential applications as
valley filters and valley valves. The realization of emerging robust helical
surface states in realistic material is also discussed.Comment: 5 pages, 4 figures; submitted to Phys. Rev. Lett. on Nov. 25. 201
Generalized Coupled-line All-Pass Phasers
Generalized coupled-line all-pass phasers, based on transversally-cascaded
(TC), longitudinally-cascaded (LC) and hybrid-cascaded (HC) coupled
transmission line sections, are presented and demonstrated using analytical,
full-wave and experimental results. It is shown that for N commensurate
coupled-line sections, LC and TC phasers exhibit N group delay peaks per
coupled-line section harmonic frequency band, in contrast to the TC
configuration, which exhibits only one peak within this band. It is also shown
that for a given maximum achievable coupling-coefficient, the HC configuration
provides the largest group delay swing. A wave-interference analysis is finally
applied to the various coupled-line phasers, explaining their unique group
delay characteristics based on physical wave-propagation mechanisms.Comment: 10 pages, 11 figure
Thumb function and appearance following treatment of Wassel type III duplication thumbs
AbstractObjectiveThe purpose of our study is to evaluate thumb function and appearance after surgical correction of Wassel type III thumbs polydactyly.MethodsWe have reconstructed 28 cases of Wassel type III duplication thumbs, in which the duplicated digits were equal or almost equal in size by ablation of a radial digit. The extra thumb is osteotomized at the bifurcation level and excised except for the distal bone fragment supporting the nail bed and fillet flap. Meanwhile, the nail of the retained thumb should be reserved completely, and if the nail has relatively poor appearance it should be repaired by nail lengthening surgery. Eighteen cases were followed up for more than 3 years and were available for assessment using the Japanese Society for Surgery of the Hand evaluation form. The average age at follow-up was 5 years. The size of the nail and distal phalanx was measured to assess the growth of the thumb.ResultsAn average functional point was 12 points (maximum 14 points) and the cosmetic score averaged 3.6 (maximum 4 points) after the assessment. Slightly small nails without a central ridge were deemed acceptable. Second revision surgery is seldom. Long-term results after surgical reconstruction for duplication thumbs were excellent, and all patients and parents were satisfied with the cosmetic and functional results.ConclusionsThis procedure is a helpful and effective way to provide functional and aesthetical thumb for Wassel type III duplication thumbs
Millimeter Spectral Line Mapping Observations Toward Four Massive Star Forming HII Regions
We present spectral line mapping observations toward four massive
star-forming regions (Cepheus A, DR21S, S76E and G34.26+0.15), with the IRAM 30
meter telescope at 2 mm and 3 mm bands. Totally 396 spectral lines from 51
molecules, one helium recombination line, ten hydrogen recombination lines, and
16 unidentified lines were detected in these four sources. An emission line of
nitrosyl cyanide (ONCN, 14-13) was detected in G34.26+0.15,
as first detection in massive star-forming regions. We found that the
-CH and NHD show enhancement in shocked regions as
suggested by evidences of SiO and/or SO emission. Column density and rotational
temperature of CHCN were estimated with the rotational diagram method for
all four sources. Isotope abundance ratios of C/C were derived
using HCN and its C isotopologue, which were around 40 in all four
massive star-forming regions and slightly lower than the local interstellar
value (65). N/N and O/O abundance ratios in
these sources were also derived using double isotopic method, which were
slightly lower than that in local interstellar medium. Except for Cep A,
S/S ratio in the other three targets were derived, which were
similar to that in the local interstellar medium. The column density ratios of
N(DCN)/N(HCN) and N(DCO)/N(HCO) in these sources were more than two
orders of magnitude higher than the elemental [D]/[H] ratio, which is
1.510. Our results show the later stage sources, G34.26+0.15 in
particular, present more molecular species than earlier stage ones. Evidence of
shock activity is seen in all stages studied.Comment: 32 pages, 11 figures, 8 tables, accepted for publication in MNRA
Semi-continuous anaerobic digestion for biogas production: influence of ammonium acetate supplement and structure of the microbial community
A Gigantic Mid-Infrared Outburst in an Embedded Class-I Young Stellar Object J064722.95+031644.6
We report the serendipitous discovery of a giant mid-infrared (MIR) outburst
from a previously unknown source near a star-forming region in the
constellation Monoceros. The source gradually brightened by a factor of 5 from
2014 to 2016 before an abrupt rise by a factor of more than 100 in 2017. A
total amplitude increase of >500 at 4.5 microns has since faded by a factor of
about 10. Prior to the outburst, it was only detected at wavelengths longer
than 1.8 microns in UKIDSS, Spitzer, and Herschel with a spectral energy
distribution of a Class I Young Stellar Object (YSO). It has not been detected
in recent optical surveys, suggesting that it is deeply embedded. With a
minimum distance of 3.5 kpc, the source has a bolometric luminosity of at least
9 in the quiescent state and 400 at the peak of the
eruption. The maximum accretion rate is estimated to be at least a few
year. It shares several common properties with
another eruptive event, WISE~J142238.82-611553.7: exceptionally large
amplitude, featureless near-infrared spectrum with the exception of H_2 lines,
intermediate eruption duration, an embedded Class I YSO, and a low radiative
temperature (<600-700 K) in outburst. We interpret that the radiation from the
inner accretion disk and young star is obscured and reprocessed by either an
inflated outer disk or thick dusty outflow on scales > 6.5 AU during the
outburst.Comment: 15 pages, 7 figures, accepted to Ap
WizardLM: Empowering Large Language Models to Follow Complex Instructions
Training large language models (LLM) with open-domain instruction following
data brings colossal success. However, manually creating such instruction data
is very time-consuming and labor-intensive. Moreover, humans may struggle to
produce high-complexity instructions. In this paper, we show an avenue for
creating large amounts of instruction data with varying levels of complexity
using LLM instead of humans. Starting with an initial set of instructions, we
use our proposed Evol-Instruct to rewrite them step by step into more complex
instructions. Then, we mix all generated instruction data to fine-tune LLaMA.
We call the resulting model WizardLM. Human evaluations on a
complexity-balanced test bed show that instructions from Evol-Instruct are
superior to human-created ones. By analyzing the human evaluation results of
the high complexity part, we demonstrate that outputs from our WizardLM model
are preferred to outputs from OpenAI ChatGPT. Even though WizardLM still lags
behind ChatGPT in some aspects, our findings suggest that fine-tuning with
AI-evolved instructions is a promising direction for enhancing large language
models. Our codes and generated data are public at
https://github.com/nlpxucan/WizardLMComment: large language model, instruction fine-tun
Archaeal lipid-inferred paleohydrology and paleotemperature of Lake Chenghai during the Pleistocene-Holocene transition
Over the past decades, paleoenvironmental studies in the Indian summer monsoon region have mainly focused on precipitation change, with few published terrestrial temperature records from the region. We analysed the distribution of isoprenoid glycerol dialkyl glycerol tetraethers (isoGDGTs) in the sediments of Lake Chenghai in southwest China across the Pleistocene-Holocene transition, to extract both regional hydrological and temperature signals for this important transition period. The lake level was reconstructed from the relative abundance of crenarchaeol in isoGDGTs (%cren) and the crenarchaeol'/crenarchaeol ratio. The %cren-inferred lake level identified a single lowstand (15.4-14.4 ka cal BP), while the crenarchaeol'/crenarchaeol ratio suggests a relatively lower lake level between 15.4-14.4 and 12.5-11.7 ka cal BP, corresponding to periods of weakened ISM during the Heinrich 1 and Younger Dryas cold event. A filtered TetraEther indeX consisting of 86 carbon atoms (TEX86 index) revealed that lake surface temperature was similar to present-day values during the last deglacial period and suggests a substantial warming of similar to 4 degrees C from the early Holocene to the mid-Holocene. Our paleotemperature record is generally consistent with other records in southwest China, suggesting that the distribution of isoGDGTs in Lake Cheng-hai sediments has potential for quantitative paleotemperature reconstruction
- …