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High precision spectroscopy of the low-lying dielectronic resonances in fluorine-like nickel ions were determined by employing the merged electron-ion beam at the heavy-ion storage ring CSRm. The measured dielectronic resonances are identified by comparing with the most recent relativistic calculation utilizing the FAC code. The first resonance at about 86 meV due to the dielectronic recombination via (2s2p6[2S1/2]6s)J=1 intermediate state was recognized. The experimental determination of the resonance position at 86 meV reaches an uncertainty of 4 meV, which allows precise determination of the 2s22p5[2P3/2] - 2s2p6[2S1/2] transition energy. The Rydberg binding energy of the 6s electron in the (2s2p6[2S1/2]6s)J=1 state is calculated by the multi-configurational Dirac-HartreeFock and stabilization methods. The determined transition energies are 149.056(4)exp(10)theo and 149.032(4)exp(6)theo, respectively. Moreover, the transition energy has also been calculated by fully relativistic and ab initio approaches. Individual theoretical contributions are evaluated by employing the core-Hartree and Kohn-Sham screening potentials, respectively. High-order QED and correlation effects contribute prominently to the total transition energy. The present DR precision spectroscopy study at the CSRm paves the way for future precision measurements of atomic energy levels with heavier highly charged ions., Comment: 12 pages, 8 figures

Employing two state-of-the-art methods, multiconfiguration Dirac--Hartree--Fock and second-order many-body perturbation theory, highly accurate calculations are performed for the lowest 272 fine-structure levels arising from the $2s^{2} 2p^{3}$, $2s 2p^{4}$, $2p^{5}$, $2s^{2} 2p^{2} 3l$~($l=s,p,d$), $2s 2p^{3}3l$ ($l=s,p,d$), and $2p^{4} 3l$ ($l=s,p,d$) configurations in nitrogen-like Ge XXVI. Complete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Land\'e $g_{J}$-factors, and E1, E2, M1, M2 line strengths, oscillator strengths, and transition rates among these 272 levels are provided. Comparisons are made between the present two data sets, as well as with other available experimental and theoretical values. The present data are accurate enough for identification and deblending of emission lines involving the $n=3$ levels, and are also useful for modeling and diagnosing fusion plasmas.

The GECAM mission consists of two identical microsatellites (GECAM-A and GECAM-B). Each satellite is equipped with 25 gamma-ray detectors (GRD) and 8 charged particle detectors (CPD). The main scientific objective of the GECAM mission is to detect gamma-ray bursts (GRBs) associated with the gravitational wave events produced by the merging of binary compact stars. After the launch on Dec. 10, 2020 , we carried out a series of on orbit tests. This paper introduces the test results of the GECAM-B satellite. According to the in-flight performance, the energy band for gamma-ray detection of GECAM-B is from about 7 keV to 3.5 MeV. GECAM-B can achieve prompt localization of GRBs. For the first time, GECAM-B realized a quasi-real-time transmission of trigger information using Beidou-3 RDSS. Keywords GECAM, gamma-ray burst, gravitational wave, GRD, CPD, Comment: 16 pages, 8 figures

One month after launching Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM), a bright thermonuclear X-ray burst from 4U~0614+09, was observed on January 24, 2021. We report the time-resolved spectroscopy of the burst and a burst oscillation detection at 413 Hz with a fractional amplitude 3.4\% (rms). This coincides with the burst oscillation previously discovered with \textit{Swift}/BAT \citep{Strohmayer2008}, and therefore confirms the spin frequency of this source. This burst is the brightest one in the normal bursts (except the superburst) ever detected from 4U~0614+09, which leads to an upper limit of distance estimation as 3.1 kpc. The folded light curve during the burst oscillation shows a multi-peak structure, which is the first case observed during a single burst oscillation in nonpulsating sources. The multi-peak profile could be due to additional harmonics of the burst oscillation, which is corresponding to several brighter/fainter spots at the stellar surface.

As the main detector of the GECAM satellite, the calibration of the energy response and detection efficiency of the GRD detector is the main content of the ground-based calibration. The calibration goal requires the calibrated energy points to sample the full energy range (8 keV-2 MeV) as much as possible. The low energy band (8-160 keV) is calibrated with the X-ray beam, while the high energy band (>160 keV) with radioactive sources. This article mainly focuses on the calibration of the energy response and detection efficiency in the 8-160 keV with a refined measurement around the absorption edges of the lanthanum bromide crystal. The GRD performances for different crystal types, data acquisition modes, working modes, and incident positions are also analyzed in detail. We show that the calibration campaign is comprehensive, and the calibration results are generally consistent with simulations as expected., 16 pages,46 figures

Introduction The results of previous systematic reviews (SRs) and meta-analyses on acupuncture for post-acute stroke dysphagia have provided conflicting evidence. This systematic review of overviews will aim to summarize and evaluate the quality of the existing SRs and meta-analyses with the aim of identifying whether acupuncture could provide a therapeutic option to treat patients with dysphagia post-acute stroke. Methods A systematic search of seven electronic databases (Pubmed, EMBASE, Cochrane library, CNKI, Wanfang, SinoMed and VIP) will be performed according to a predefined search strategy for SRs and meta-analyses of randomized controlled trials (RCTs) and quasi-RCTs on acupuncture for dysphagia post-acute stroke. Two authors will independently select SRs and meta-analyses and collect appropriate data. The reporting quality of included SRs and meta-analyses will be assessed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The revised Assessment of Multiple Systematic Reviews (AMSTAR 2) will be used to assess the quality of the SRs and meta-analyses. If necessary, GRADE will be used to rate the quality of evidence. Results This overview will identify current SRs and meta-analyses of RCTs or quasi-RCTs of acupuncture treatment for dysphagia post-acute stroke. Discussion The current evidence will be evaluated to help answer the question - is acupuncture a potentially effective treatment for dysphagia after stroke?

Employing two state-of-the-art methods, multiconfiguration Dirac--Hartree--Fock and second-order many-body perturbation theory, highly accurate calculations are performed for the lowest 272 fine-structure levels arising from the $2s^{2} 2p^{3}$, $2s 2p^{4}$, $2p^{5}$, $2s^{2} 2p^{2} 3l$~($l=s,p,d$), $2s 2p^{3}3l$ ($l=s,p,d$), and $2p^{4} 3l$ ($l=s,p,d$) configurations in nitrogen-like Ge XXVI. Complete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Land�� $g_{J}$-factors, and E1, E2, M1, M2 line strengths, oscillator strengths, and transition rates among these 272 levels are provided. Comparisons are made between the present two data sets, as well as with other available experimental and theoretical values. The present data are accurate enough for identification and deblending of emission lines involving the $n=3$ levels, and are also useful for modeling and diagnosing fusion plasmas.