The integration of nanophotonics and atomic physics has been a long-sought goal that would open new frontiers for optical physics, including novel quantum transport and many-body phenomena with ...photon-mediated atomic interactions. Reaching this goal requires surmounting diverse challenges in nanofabrication and atomic manipulation. Here we report the development of a novel integrated optical circuit with a photonic crystal capable of both localizing and interfacing atoms with guided photons. Optical bands of a photonic crystal waveguide are aligned with selected atomic transitions. From reflection spectra measured with average atom number N=1.1+/-0.4, we infer that atoms are localized within the waveguide by optical dipole forces. The fraction of single-atom radiative decay into the waveguide is Γ1D/Γ'≃(0.32±0.08), where Γ1D is the rate of emission into the guided mode and Γ' is the decay rate into all other channels. Γ1D/Γ' is unprecedented in all current atom-photon interfaces.
We consider the problems of correct finding of normal quasisolutions of operator equations whose operator is a superposition of linear and nonlinear operators. The nonlinear operator is a modulo ...operation. In the case where the linear operator is completely continuous, we establish sufficient conditions for the regularization parameter guaranteeing the convergence of the solution of regularized problem to the quasisolution of the exact operator equation depending on the error of the linear operator of the problem.
•A novel interface method is developed for multiphase SPH.•An algebraic indicator is proposed for accurate and efficient interface detection.•A new surface tension formulation based on local surface ...reconstruction is developed.•The present surface tension formulation demonstrates its accuracy and efficiency.
A novel interface method is developed in this paper for two-dimensional smoothed particle hydrodynamics (SPH) modelings of multiphase flows. The present interface method aims to resolve two essential issues in the multiphase flow simulations: the interface detection and the implementation of surface tension force. Specifically, a novel and easy-to-implement algebraic indicator is proposed to detect the interface particles. And the surface tension force is locally implemented on the interface particles by reconstructing arc lines connecting three adjacent interface particles. Compared with the previous surface reconstruction method, the present method utilizes fewer particles in the local evaluation of surface tension. The novel algebraic indicator provides more accurate and efficient detection of the interface particles, especially for the sparse or aggregated particle distributions. In the meantime, the present surface tension formulation removes the tedious process of evaluating gradient of the color index and thus significantly improves the numerical efficiency. The accuracy, flexibility and efficiency of the present interface method are comprehensively evaluated through four numerical examples, namely the sloshing in a rectangular tank, oscillation of elliptic droplet, Laplace law for a stationary droplet, and air bubble rising in water. The good agreement of the present numerical results with the published results demonstrates that the novel interface method proposed in this paper can precisely detect the interface particles with appealing sharpness, and recover the surface tension force accurately and efficiently.
In this paper, we solve the new evolution equation for high energy scattering amplitude that stems from the Gribov-Zwanziger approach to the confinement of quarks and gluons. We found that (1) the ...energy dependence of the scattering amplitude turns out to be the same as for QCD Balitsky, Fadin, Kuraev and Lipatov (BFKL) evolution, (2) the spectrum of the new equation does not depend on the details of the Gribov-Zwanzinger approach, and (3) all eigenfunctions coincide with the eigenfunctions of the QCD BFKL equation at large transverse momenta κ ≥ 1 . The numerical calculations show that there exist no new eigenvalues with the eigenfunctions which decrease faster than solutions of the QCD BFKL equation at large transverse momenta. The structure of the gluon propagator in the Gribov-Zwanziger approach, that stems from the lattice QCD and from the theoretical evaluation, results in the exponential suppression of the eigenfunctions at long distances and in the resolution of the difficulties, which the color glass condensate and some other approaches, based on perturbative QCD, face at large impact parameters. We can conclude that the confinement of quark and gluons, at least in the form of the Gribov-Zwanziger approach, does not influence on the scattering amplitude except for solving the long-standing theoretical problem of its behavior at large impact parameters.
Prussian blue analogues with formulae Ni
3
Co(CN)
6
2
·16H
2
O(
I
), Cu
3
Co(CN)
6
2
·17H
2
O(
II
), Ni
3
Fe(CN)
6
2
·15H
2
O(
III
) and Cu
3
Fe(CN)
6
2
·13H
2
O(
IV
) have been synthesized. The ...thermal decomposition of all complexes in oxidizing (air), reducing (hydrogen) and inert (argon) atmospheres was studied in the temperature range from 20 to 1000 °C. TG–DSC curves were obtained; analysis of solid thermolysis products was performed. It was established that the decomposition process of all the studied compounds in air ends up to 450–500 °C, and mass loss continues up to 1000 °C in argon. Solid products of thermolysis are oxides of central ions (NiO, CuO, Co
3
O
4
, Fe
3
O
4
) in air; mixtures of metals or Ni
3
Fe (
III
) in argon; Ni and Co (
I
) and Ni
3
Fe + Fe(
III
), and mixtures of Cu + Co (
II
) and Cu + Fe(
IV
) in hydrogen. Hexacyanocobaltates are reduced at lower temperatures and more fully than hexacyanoferrates under the same conditions.
Abstract
Although low-frequency quasiperiodic oscillations (LFQPOs) are commonly detected in the X-ray light curves of accreting black hole X-ray binaries, their origin still remains elusive. In this ...study, we conduct phase-resolved spectroscopy in a broad energy band for LFQPOs in MAXI J1820+070 during its 2018 outburst, utilizing Insight-HXMT observations. By employing the Hilbert–Huang transform method, we extract the intrinsic quasiperiodic oscillation (QPO) variability, and obtain the corresponding instantaneous amplitude, phase, and frequency functions for each data point. With well-defined phases, we construct QPO waveforms and phase-resolved spectra. By comparing the phase-folded waveform with that obtained from the Fourier method, we find that phase folding on the phase of the QPO fundamental frequency leads to a slight reduction in the contribution of the harmonic component. This suggests that the phase difference between QPO harmonics exhibits time variability. Phase-resolved spectral analysis reveals strong concurrent modulations of the spectral index and flux across the bright hard state. The modulation of the spectral index could potentially be explained by both the corona and jet precession models, with the latter requiring efficient acceleration within the jet. Furthermore, significant modulations in the reflection fraction are detected exclusively during the later stages of the bright hard state. These findings provide support for the geometric origin of LFQPOs and offer valuable insights into the evolution of the accretion geometry during the outburst in MAXI J1820+070.
We present observations of supernova (SN) 2017ens, discovered by the ATLAS survey and identified as a hot blue object through the GREAT program. The redshift z = 0.1086 implies a peak brightness of ...Mg = −21.1 mag, placing the object within the regime of superluminous supernovae. We observe a dramatic spectral evolution, from initially being blue and featureless, to later developing features similar to those of the broadlined Type Ic SN 1998bw, and finally showing ∼2000 km s−1 wide H and Hβ emission. Relatively narrow Balmer emission (reminiscent of a SN IIn) is present at all times. We also detect coronal lines, indicative of a dense circumstellar medium. We constrain the progenitor wind velocity to ∼50-60 km s−1 based on P-Cygni profiles, which is far slower than those present in Wolf-Rayet stars. This may suggest that the progenitor passed through a luminous blue variable phase, or that the wind is instead from a binary companion red supergiant star. At late times we see the ∼2000 km s−1 wide H emission persisting at high luminosity (∼3 × 1040 erg s−1) for at least 100 day, perhaps indicative of additional mass loss at high velocities that could have been ejected by a pulsational pair instability.
Objectives
Supplementation of high protein oral nutrition shakes supplemented with β-hydroxy-β-methylbutyrate (HP-HMB) has been shown to improve muscle mass, muscle strength, and physical performance ...in older adults, but the roles of HP-HMB supplementation on the intramuscular adiposity remained unknown. This 12-week randomized controlled trial evaluated the changes of muscle mass, muscle strength, physical performance and intramuscular adiposity among community-dwelling pre-frail older persons.
Methods
This was an open-label, parallel group, randomized controlled trail that enrolled 70 community-dwelling pre-frail older persons without active or uncontrolled conditions, disability or dementia. The intervention group was provided with two services of HP HMB (Ensure® Plus Advance containing 3g HMB) per day for 12 weeks, and the control group was provided with professional nutritional counselling for sufficient protein intake. All participants received functional assessments, laboratory tests and magnetic resonance imaging (MRI) of the dominant leg before and after study. Intramuscular adipose tissue (IMAT) and the mid-thigh cross-sectional area (CSA) of muscle were obtained by MRI, and the IMAT-to-CSA ratio was calculated to evaluate intramuscular adiposity.
Results
Overall, 62 participants (mean age: 71.1±3.8 years, 69.4% female) completed the study (HP-HMB group: 29, control group: 33) and comparisons of baseline characteristics between groups were not statistically different. For the primary outcome, HP-HMB group showed significant improvements in the CSA of mid-thigh muscle (mean increase of CSA: 149.1±272.3 for HMB group vs −22.9±309.1 mm
2
for control group, P=0.045). The improvement of MNA-SF was borderline (0.28±0.75 vs. −0.15±0.94, P=0.064), but serum levels of Vit D were significantly increased in the HMB group (3.83±8.18 vs. −1.30±4.81 ng/mL, P=0.002). Moreover, the body weight and BMI were significantly increased in the HMB group (1.10±1.18 vs. 0.24±1.13 kg, P=0.005; 0.56±0.68 vs. 0.22±0.47 kg/m
2
, P=0.019). In particular, the IMAT-to-CSA ratio was reduced in the HMB group (−0.38±1.21 vs. −0.02±2.56 %, P=0.06). Using the generalized estimating equation, we found that SPPB score in chair rise test was significantly improved (β=0.71, 95% C.I.0.09–1.33, P=0.026).
Conclusions
The 12-week supplementation with high protein oral nutrition shake supplemented with 3g HMB per day significantly increased muscle mass, as well as nutritional status and physical performance, and ameliorated the intramuscular adiposity of pre-frail older persons. Further study is needed to explore the long-term benefits of HP-HMB supplementation on muscle and metabolic health for older adults.
Description of excitation energy transfer (EET) in large multichromophoric systems of nanoscale size is often inconsistent with the classical Förster model. In this work, abnormal enhancement of ...emission in a heterogeneous mixture of J-aggregates of donor and acceptor thiamonomethinecyanine dyes is reported, which surpasses the sum of emissions of the neat donor and acceptor J-aggregate solutions. Despite the tight overlap of the photoluminescence emission band of the donor J-aggregate and the absorption band of the acceptor J-aggregate, a direct dipole–dipole resonant energy transfer was found to have only a marginal contribution to the overall enhancement, with efficiency less than 10%, whereas the major contribution came from the non-Förster mechanism, which was interpreted as exciplex formation in the heterogeneous system. The enhanced emission was preceded by the exciton migration within the J-aggregate to specific sites, where a competition between formation of exciplex and excimer took place due to interaction with the foreign or own dimers in the ground state, respectively, due to which the excitation lifetime exceeded that of a free exciton in the neat J-aggregate.
Synchrotron radiation-based Fourier transform IR (SR-FTIR) microspectroscopy has been developed as a rapid, direct, non-destructive and bioanalytical technique. This technique, taking advantage of ...synchrotron light brightness and a small effective source size, is capable of exploring the molecular chemistry within the microstructures of a biological tissue without the destruction of inherent structures at ultraspatial resolutions within cellular dimensions. This is in contrast to traditional 'wet' chemical methods, which, during processing for analysis, often result in the destruction of the intrinsic structures of feeds. To date there has been very little application of this technique to the study of feed materials in relation to animal nutrient utilisation. The present article reviews four applications of the SR-FTIR bioanalytical technique as a novel approach in animal nutrition and feed science research. Application 1 showed that using the SR-FTIR technique, intensities and the distribution of the biological components (such as lignin, protein, lipid, structural and non-structural carbohydrates and their ratios) in the microstructure of plant tissue within cellular dimensions could be imaged. The implication from this study is that we can chemically define the intrinsic feed structure and compare feed tissues according to spectroscopic characteristics, functional groups, spatial distribution and chemical intensity. Application 2 showed that the ultrastructural-chemical makeup and density of yellow- and brown-seeded Brassica rape could be explored. This structural-chemical information could be used for the prediction of rapeseed quality and nutritive value for man and animals and for rapeseed breeding programmes for selecting superior varieties for special purposes. More research is required to define the extent of differences that exist between the yellow- and brown-seeded Brassica rape. Application 3 showed with the SR-FTIR technique that chemical differences in the ultrastructural matrix of endosperm tissue between Harrington (malting-type) and Valier (feed-type) barley in relation to rumen degradation characteristics could be identified. The results indicated that the greater association of the protein matrix with the starch granules in the endosperm tissue of Valier barley may limit the access of ruminal micro-organisms to the starch granules and thus reduce the rate and extent of rumen degradation relative to that of Harrington barley. It is the first time that the microstructural matrix in the endosperm of barley has been revealed by using the SR-FTIR technique, which makes it possible to link feed intrinsic structures to nutrient utilisation and digestive behaviour in ruminants. Application 4 showed with the SR-FTIR technique that the chemical features of various feed protein (amide I) secondary structures (such as feather, wheat, oats and barley) could be quantified. With a multi-component fitting program (Lorentz function), the results showed feather containing about 88% beta-sheet and 4% alpha-helix, barley containing about 17% beta-sheet and 71% alpha-helix; oats containing about 2% beta-sheet and 92% alpha-helix; and wheat containing about 42% beta-sheet and 50% alpha-helix. The relative percentage of the two may influence protein value. A high percentage of beta-sheet may reduce the access of gastrointestinal digestive enzymes to the protein structure. Further study is required on feed protein secondary structures in relation to enzyme accessibility and digestibility. In conclusion, the SR-FTIR technique can be used for feed science and animal nutrition research. However, the main disadvantage of this technique is the requirement for a special light source; a synchrotron beam.
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