Analysis of Bright Source Hardness Ratios in the 4 yr Insight-HXMT Galactic Plane Scanning Survey Catalog

We conduct a statistical analysis of the hardness ratio(HR)for bright sources in the 4 yr Galactic Plane Scanning Survey catalog of Insight-HXMT.Depending on the stable(variable)flux F_(s)(F_(v))or spectrum S_(s)(S_(v))of each source,the bright sources are classified into three groups:F_(v)&S_(v),F_(v)&S_(s),and F_(s)&_(s).Our study of the HR characteristics in different types of sources reveals that accretion-powered neutron star(NS)low-mass X-ray binaries(LMXBs)exhibit softer energy spectra than NS high-mass X-ray binaries(HMXBs),but harder energy spectra than black hole binaries in most cases.This difference is probably due to their different magnetic field strengths.Additionally,Fv&Sv LMXBs tend to be harder than Fv&Ss LMXBs below 7 keV,while the opposite is true for HMXBs.Our results suggest that LMXBs may dominate unclassified sources,and NS binaries are likely to be the primary type of X-ray binaries with ambiguous compact stars.By comparing the HR of transient sources in their outburst and low-flux states,it is found that the averaged HR of four sources in the two states are roughly comparable within uncertainties.We also investigate the spatial properties of the three groups and find that Fv&Sv sources are mainly located in the longitude of-20°<l<9°,Fv&Ss sources cross the Galactic Plane,and Fs&Ss sources are predominantly concentrated in 19°<l<42°.In addition,analyzing the HR spatial distributions shows the absorption of soft X-rays(primarily below 2 keV)in the Galactic Plane.

Timing analysis of the black hole candidate EXO 1846–031 with Insight-HXMT monitoring

We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be classified roughly into four different states.Type-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this work.Meanwhile,we study various physical quantities related to QPO frequency.The QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain it.The relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.

Tissue and regional expression patterns of dicistronic tRNA–mRNA transcripts in grapevine (Vitis vinifera) and their evolutionary co-appearance with vasculature in land plants

Transfer RNAs(tRNA)are crucial adaptor molecules between messenger RNA(mRNA)and amino acids.Recent evidence in plants suggests that dicistronic tRNA-like structures also act as mobile signals for mRNA transcripts to move between distant tissues.Co-transcription is not a common feature in the plant nuclear genome and,in the few cases where polycistronic transcripts have been found,they include non-coding RNA species,such as small nucleolar RNAs and microRNAs.It is not known,however,the extent to which dicistronic transcripts of tRNA and mRNAs are expressed in field-grown plants,or the factors contributing to their expression.We analysed tRNA–mRNA dicistronic transcripts in the major horticultural crop grapevine(Vitis vinifera)using a novel pipeline developed to identify dicistronic transcripts from high-throughput RNA-sequencing data.We identified dicistronic tRNA–mRNA in leaf and berry samples from 22 commercial vineyards.Of the 124 tRNA genes that were expressed in both tissues,18 tRNA were expressed forming part of 19 dicistronic tRNA–mRNAs.The presence and abundance of dicistronic molecules was tissue and geographic sub-region specific.In leaves,the expression patterns of dicistronic tRNA–mRNAs significantly correlated with tRNA expression,suggesting that their transcriptional regulation might be linked.We also found evidence of syntenic genomic arrangements of tRNAs and protein-coding genes between grapevine and Arabidopsis thaliana,and widespread prevalence of dicistronic tRNA–mRNA transcripts among vascular land plants but no evidence of these transcripts in non-vascular lineages.This suggests that the appearance of plant vasculature and tRNA–mRNA occurred concurrently during the evolution of land plants.

Localization Method for the Pointing Observation with the Collimated Telescopes of Insight-HXMT

An accurate target source position is sometimes useful for the pointing observation with the collimated telescopes of the Hard X-ray Modulation Telescope(Insight-HXMT),which is determined by the reliability of the instrumental response.Insight-HXMT has the unique design that all three main payloads(LE,ME and HE)consist of detector groups with three fields of views(FOVs)whose orientations differ by 60°.As the point-spread functions are different at different positions in the FOV coordinates,the count rate ratios between the detector groups depend on the position of an X-ray source in the FOVs.Based on the multi-FOV design,we develop a localization method for an X-ray source in the pointing observation of Insight-HXMT.The accuracy of the method is investigated with the pointing observations of the Crab with different exposures.We find that the statistical error decreases with the exposure,and the systematic error is dominant for the exposure>128 s.With the exposure of1024 s,the total error is 0°.015 for the Crab.This method can effectively distinguish the Rapid Burster H 1730–333and Slow Burster GX 354–0,which are only 0°.5 apart and can both contribute to bursts in the light curve obtained by Insight-HXMT.We also apply the pointing observation localization method to locate the X-ray counterpart of FRB 200428 with high precision.The located position is consistent with SGR J1935+2154 within 1σuncertainty of 10′,which provides important evidence that fast radio bursts can originate from magnetars.

Involvement of NLRP3-inflammasome pathway in noise-induced hearing loss

The inflammasome is a multiprotein oligomer in the cell cytoplasm and is part of the innate immune system.It plays a crucial role in the pathological process of noise-induced hearing loss(NIHL).However,the mechanisms of NLR family pyrin domain containing 3(NLRP3)inflammasome activation in NIHL have not been clearly demonstrated.In this study,miniature pigs were exposed to white noise at 120 dB(A)and auditory brainstem response measurements were used to measure their hearing function.Immunofluorescence staining,confocal laser scanning microscopy,western blot assay,and quantitative reverse transcription-polymerase chain reaction were used to analyze inflammasome-related protein distribution and expression.NLRP3,interleukin-1β,interleukin-18,and cleaved-caspase-1 were highly expressed in the cochlea after 120 dB(A)white noise exposure.Our findings suggest that NLRP3-inflammasomes in the cochlea may be activated after acoustic trauma,which may be an important mechanism of noise-induced hearing loss.

公共教育对国家认同的塑造和培养——以美国为例

国家认同是支撑民族国家合法性、维系国家团结和统一的一种重要的公民意识。公共教育是塑造和培养国家认同的主要途径之一。世界各国以塑造和培养国家认同为首要任务的公共教育政策,主要遵循同化主义、多元文化主义、以政治认同为核心、以国家建构为核心以及混合型等模式。美国作为社会构成复杂的移民国家,其公共教育体系受到自由同化主义、多元文化主义和以政治认同为核心等模式的影响,呈现出一种混合型的国家认同培养模式。在最近几十年中,美国的公共教育体系受到多元文化主义、教育“私有化”改革和全球化的冲击,在公民意识和国家认同的培养上遇到巨大挑战。美国的案例表明,国家认同的塑造和培养是长期的、复杂的、动态的社会任务。政府需要持续思考和不断探索,寻找和尝试适合本国社会结构且能兼顾国家认同塑造和族群文化保护的公共教育模式。

Development of Rural Tourism in Liaoning Province from the Perspective of Types

With the vigorous development of the tourism industry,the types of tourism become rich and diverse,and the development models have their own characteristics.At present,rural tourism has become a hot spot in the development of tourism,and it is also a driver of rural revitalization.However,its development type and development model are not mature yet,and there are still some fundamental problems in the process of development.Based on the development status of rural tourism in Liaoning Province,an in-depth survey was carried out on the types and development models of rural tourism in Liaoning Province,and its basic types and development models are clarified,to explore the deep-rooted problems existing in the development of rural tourism in Liaoning Province.Besides,the development models adopted in different regions of China were compared to find the universally applicable rules for the development of rural tourism.Finally,according to the distribution of rural tourism resources,the development direction was clearly defined,supporting policy recommendations were proposed,including adjusting and upgrading the existing types and development models,and implementing development strategies in a targeted manner to promote the sustainable development of rural tourism in Liaoning Province.

Insight-HXMT observations of the first binary neutron star merger GW170817

Finding the electromagnetic(EM) counterpart of binary compact star merger, especially the binary neutron star(BNS) merger,is critically important for gravitational wave(GW) astronomy, cosmology and fundamental physics. On Aug. 17, 2017,Advanced LIGO and Fermi/GBM independently triggered the first BNS merger, GW170817, and its high energy EM counterpart,GRB 170817 A, respectively, resulting in a global observation campaign covering gamma-ray, X-ray, UV, optical, IR, radio as well as neutrinos. The High Energy X-ray telescope(HE) onboard Insight-HXMT(Hard X-ray Modulation Telescope) is the unique high-energy gamma-ray telescope that monitored the entire GW localization area and especially the optical counterpart(SSS17 a/AT2017 gfo) with very large collection area(~1000 cm^2) and microsecond time resolution in 0.2-5 MeV. In addition,Insight-HXMT quickly implemented a Target of Opportunity(ToO) observation to scan the GW localization area for potential X-ray emission from the GW source. Although Insight-HXMT did not detect any significant high energy(0.2-5 MeV) radiation from GW170817, its observation helped to confirm the unexpected weak and soft nature of GRB 170817 A. Meanwhile,Insight-HXMT/HE provides one of the most stringent constraints(~10^(-7) to 10^(-6) erg/cm^2/s) for both GRB170817 A and any other possible precursor or extended emissions in 0.2-5 MeV, which help us to better understand the properties of EM radiation from this BNS merger. Therefore the observation of Insight-HXMT constitutes an important chapter in the full context of multi-wavelength and multi-messenger observation of this historical GW event.

Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band(1-250 ke V) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 Me V. It was designed to perform pointing, scanning and gamma-ray burst(GRB)observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed.Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.