The Lobster Eye Imager for Astronomy Onboard the SATech-01 Satellite

The Lobster Eye Imager for Astronomy(LEIA),a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe mission,was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on2022 July 27.In this paper,we introduce the design and on-ground test results of the LEIA instrument.Using stateof-the-art Micro-Pore Optics(MPO),a wide field of view of 346 square degrees(18.6°×18.6°)of the X-ray imager is realized.An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons,and four large-format complementary metal-oxide semiconductor(CMOS)sensors,each of size 6 cm×6 cm,are used as the focal plane detectors.The instrument has an angular resolution of 4’-8’(in terms of FWHM)for the central focal spot of the point-spread function,and an effective area of 2-3 cm^(2) at 1 keV in essentially all the directions within the field of view.The detection passband is 0.5-4 keV in soft X-rays and the sensitivity is2-3×10^(-11) erg s^(-1) cm^(-2)(about 1 milliCrab)with a 1000 s observation.The total weight of LEIA is 56 kg and the power is 85 W.The satellite,with a design lifetime of 2 yr,operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes.LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation,and by optimizing the working setups of the instrumental parameters.In addition,LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band,albeit with limited useful observing time available.

Nano Brazing of Pt-Ag Nanoparticles under Femtosecond Laser Irradiation

Nano brazing of Pt-Ag nanoparticles with nano Ag filler metal is reported in this letter, which presents an effective way to join nanoobjects by femtosecond laser irradiation. The nano brazed interface between Pt-Ag and Ag showed good lattice matching along(111)_(Ag) //(111)_(Ag-Pt). Lattice mismatch can hardly be observed at the interface between the filler metal and Pt-Ag nanoparticle, which is important for the joint strength and normally does not occur during joining. The very low mismatch also suggested that melting and solidification occurred during nano brazing by femtosecond laser. The role of Brownian motion on the nano joining process is also discussed in this paper.

ORTHOGONAL POLYNOMIAL EXPANSIONS OF THERMODYNAMICPROPERTIES OF BINARY AND TERNARY SYSTEMS

Orthogonal polynomial expansions are ased to present integral properties of binary and ternary sgstems. The partial property of each component can be expressed with the same set of coeffcients. It was shown that the coefficients are completely independent. Ternary system of Pb-Sb-Sn and its three binary sub-systems are calculated as example.

Intensities and shifts of Lyman and Balmer lines of hydrogen-like ions in high density plasmas

The spectral line intensities and line shifts of Lyman and Balmer series for transitions up to n=5 of hydrogen-like ion are studied in plasmas with densities and temperatures in the ranges n_(c)~10^(18)-10^(21)cm^(-3),T_(e)=0.3e1.2 eV respectively.The screened potential used to describe the interaction between charged particles includes the electron exchange-correlation and finite-temperature gradient effects and is valid for both weakly and strongly coupled plasmas.The dependencies of alpha,beta and gamma line shifts of Lyman and Balmer series on plasma density(for fixed temperature)and temperature(for fixed density)are investigated.The results for the H_(a)line shifts are compared with the available high-density experimental data.

Dynamics of N^(5+)-H electron capture in Debye plasmas

The electron capture in N^(5+)-H collisions imbedded in a Debye plasma is studied by using the two-center atomic orbital close-coupling method in the energy range from 1 keV/u to 200 keV/u.The atomic orbitals and electron binding energies of atomic states are calculated within the Debye-Huckel approximation of the screened Coulomb potential and used in atomic orbital close-coupling dynamics formalism to calculate the electron capture cross sections.The electron capture cross sections and the charge transfer spectral lines of N^(4+)(1s^(2)nl)for a number of representative screening parameter values are presented and discussed.It is found that the screening of Coulomb interactions affects the entire collision dynamics and the magnitude and energy behavior of state-selective cross sections.The changes in electron binding energies and capture cross sections when the interaction screening varies introduce dramatic changes in the radiation spectrum of N^(4+)(1s^(2)nl)capture states with respect to the unscreened interaction case.

汶川M_S8.0地震后中国四川西部温泉气的地球化学特征

为了探讨汶川MS8.0地震与温泉气地球化学特征之间的关系,分别在2008年6月、10月和2009年6月对中国西南地区四川西部32处温泉气进行了调查和样品采集,并针对三批次气样中的化学成分和He,Ne,C同位素比值进行了分析。数据显示,龙门山断裂带、鲜水河断裂带和岷江断裂带的温泉气中3He/4He,δ13CCO2含量在汶川大地震发生后明显增加。根据2008年6月测得的3He/4He最大值(7.42×10-6),预估在康定地区有高达62%的地幔氦增加进入到了温泉气中。随着时间的推移,地幔流体对温泉的贡献逐渐减少,但壳源气体,如有机物衍生出的CO2和CH4以及放射生成的He,其成分有所增强。温泉气的地球化学数据表明,在汶川MS8.0地震后,四川西部地区有更多的地幔流体迁移进入地壳中。

Effect of Cold-Rolling on Precipitation Phenomena in Sensitized Type 316L and 304L Austenitic Stainless Steels

Precipitation phenomena in Type 316L and 304L stainless steels were studied mainly by transmission electron microscopic (TEM) observations after cold-rolling ranging from 0% (as solution annealed) to 80% reduction in thickness, and then by sensitization treatment. Precipitates were identified by electron diffraction analysis and EDS analysis. Precipitates observed in sensitized 316L stainless steel were sigma and chi phases, whereas carbide and sigma were observed in sensitized 304L stainless steel. Recrystallized grains were formed in 30% cold-rolled and sensitized 304L. However, the tendency toward recrystallization in sensitized 316L was much lower than in 304L. Precipitation of sigma and chi phases was accelerated by cold-rolling and they were observed at grain boundaries in lower cold-rolling; they were also seen, in grain interiors in higher cold-rolling. Higher deformation induced partially recrystallization combined with precipitation, resulting in the formation of heterogeneous microstructures.

Microstructure of Nitrided Aluminum Alloys Using an Electron-Beam-Excited-Plasma (EBEP)

Nitriding of surface of aluminum alloys was carried out with using an electron-beam-excited-plasma (EBEP) technique. The EBEP is sustained by electron impact ionization with energetic electron beam. Two kinds of substrates, aluminum alloys AA5052 and AA5083, were exposed to the down flow of EBEP source at 843 K for 45min. The specimens were characterized with respect to following properties: crystallographic structure (XRD), morphology (SEM) and the cross sectional microstructures of the nitrided layer was observed using a scanning electron microscopy (SEM). There are some A12O3 particles on the surface of the nitrided AA5052 and AA5083. The A1N layers were formed on the substrates with the thickness of 4.5 fi m for AA5052 and 0.5 /z m for AA5083 . A relatively uniform nitrided surface layer composed of A1N can be observed on the AA5052 substrate. The grains size near the interfaces between the substrate and A1N layer were smaller than that near the surface. On the surface of A1N layer, the concentration of nitrogen was high and in the middle of A1N layer it had a constant concentration like the aluminum and the concentration was decreased with approaching to the interface. On the surface of nitrided AA5083, a uniform A1N layer was not formed as the reason for the high nitriding temperature.

The protein tyrosine kinase inhibitor, genistein, decreases the excitability of capsaicin-sensitive neurons

AIM : One of the primary mechanisms by which neurons regulate their excitability is through of ion channel phosphorylafion. Compounds that increase noeiceptor excitability can cause hyporalgesia or allodynia whereas compounds that decrease noeiceptor excitability can be used as analgesics to relieve pain arising from inflammation or trauma. METHODS:

Voltage-Gated Ion Channels in Nociceptors： Modulation by the cGMP-PKG pathway

AIM: Nociceptors contain a variety of ion channels that are modulated by proinflammatory mediators that may arise from tissue or nerve injury. The changes in activity of these channels, which primarily occurs through changes in intracellular pathways, may lead to the pathological states of hyperalgesia and allodynia. METHODS &RESULTS:

STCF conceptual design report (Volume 1): Physics & detector

The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.

Unexpected creep behavior in a rejuvenated metallic glass

Rejuvenation,bringing metallic glasses(MGs)to the younger and higher energy states,provides an alternative avenue to explore the interplay between the property and microstructures of MGs.In this study,the creep behavior of the Zr_(69.5)Cu_(12)Ni_(11)Al_(7.5)MGs was experimentally examined by controlling the energy state in terms of structural rejuvenation and thermal annealing.It is found that compared to the as-cast counterpart,the annealed MG at a lower energy state exhibits a higher hardness,a smaller displacement,and a lower creep rate due to the decreased free volume and the inhibited activation of the shear transformation zone.Conversely,the rejuvenated MG at a high energy state displays lower hardness and increased free volume content,yet it demonstrates superior creep resistance compared to its as-cast counterpart,which deviates from conventional understanding.This unexpected phenomenon occurs as the initial high-content free volume annihilates during creep,and strain hardening takes precedence over strain softening as the prevailing process during creep deformation,leading to a superior creep performance in extremely rejuvenated MGs.

Observation of e^(+)e^(-)→pppñπ-+c.c.

Using data taken at 29 center-of-mass energies between 4.16 and 4.70 GeV with the BESⅢdetector at the Beijing Electron Positron Collider corresponding to a total integrated luminosity of approximately 18.8 fb^(-1),the process e^(+)e^(-)→pppñπ+c.c.is observed for the first time with a statistical significance of 11.5σ.The average Born cross sections in the energy ranges of(4.160,4.380)GeV,(4.400,4.600)GeV and(4.610,4.700)GeV are measured to be(21.5±5.7±1.2)fb,(46.3±10.6±2.5)fb and(59.0±9.4±3.2)fb,respectively,where the first uncertainties are statistical and the second are systematic.The line shapes of the pñ and ppπ^(-)invariant mass spectra are consistent with phase space distributions,indicating that no hexaquark or di-baryon state is observed.

Search for hidden-charm tetraquark with strangeness in e^(+)e^(−)→K^(+)D_(s)^(∗−) D^(∗0 )+ c.c.

We report a search for a heavier partner of the recently observed Z_(cs)(3985)^(-) state,denoted as Z_(cs)^('-),in the process e^(+)e^(−)→K^(+)D_(s)^(∗−) D^(∗0 )+ c.c.,based on e^(*)e^(-)collision data collected at the center-of-mass energies of √s=4.661,4.682 and 4.699 GeV with the BESIII detector.The Z_(cs)^('-) is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark.A partial-reconstruction technique is used to isolate K^(+)recoil-mass spectra,which are probed for a potential contribution from Z_(cs)^('-)→D_(s)^(∗−) D^(∗0 )+ c.c.We find an excess of Z_(cs)^('-)→D_(s)^(*-)-D^(*0)(c.c.)candidates with a significance of 2.1o,after considering systematic uncertainties,at a mass of(4123.5±0.7_(sat)±4.7_(syst.))MeV/c^(2).As the data set is limited in size,the upper limits are evaluated at the 90%confidence level on the product of the Born cross sections(σ^(Borm))and the branching fraction(B)of Z_(cs)^('-)→D_(s)^(*-)-D^(*0),under different assumptions of the Z_(cs)^('-) mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies.The upper limits of σ^(Born).B are found to be at the level of O(1)pb at each energy.Larger data samples are needed to confirm the Z_(cs)^('-) state and clarify its nature in the coming years.

Microwave dielectric properties of CaCu_(3)Ti_(4)O_(12) ceramics:A clue to its intrinsic dielectric response

CaCu_(3)Ti_(4)O_(12)(CCTO)is a potential dielectric material with giant permittivity,good stability over the wide temperature and frequency range.However,the dielectric responses of CCTO-based ceramics are mainly investigated in the frequency of 102-106 Hz,which is far low to clarify the intrinsic dielectric feature.So,microwave dielectric properties have been investigated for the CCTO porous ceramics sintered at low temperature(≤1000°C).Good microwave dielectric properties of permittivityε=62.7,quality factor Qf=3062 GHz and temperature coefficient of the resonant frequencyτf=179 ppm/°C are achieved for the CCTO ceramics sintered at 1000°C,the dielectric loss significantly decreases two orders to 0.002 compared to that of CCTO ceramics sintered at critical temperature of 1020°C confirmed by differential scanning calorimetry(DSC).This clue indicates that giant permittivity and high loss is not intrinsic for CCTO ceramics,but derives from composition segregation,liquid phase and defects associated with internal barrier layer capacitor(IBLC).It suggests that CCTO-based ceramics is a promising microwave dielectric materials with high permittivity.

Search for the weak decayψ(3686)→■+c.c.

Using(448.1±2.9)×10^(6)ψ(3686)for the weak baryonic decayψ(3686)→Λc+∑-+c.c..The analysis procedure is optimized using a blinded method.No significant signal is observed,and the upper limit on the branching fraction(B)ofψ(3686)→Λc+∑-+c.c.is set as 1.4×10^(-5)at the 90%confidence level.

Observations of the Cabibbo-Suppressed decays Λ_(c)^(+)→nπ+π^(0),nπ^(+)π^(-)π^(+) and the Cabibbo-Favored decay Λ_(c)^(+)→nK^(-)π^(+)π^(+)

Using electron-positron annihilation data samples corresponding to an integrated luminosity of 4.5 fb-1,collected by the BESⅢdetector in the energy region between 4599.53 MeV and 4698.82 MeV,we report the first observations of the Cabibbo-suppressed decaysΛ_(c)^(+)→nπ^(+)π^(0),Λ_(c)^(+)→nπ^(+)π^(-)π^(+),and the Cabibbo-favored decayΛ_(c)^(+)→nK^(-)π^(+)π^(+)with statistical significances of 7.9σ,7.8σ,and>10σ,respectively.The branching fractions of these decays are measured to be B(Λ_(c)^(+)→nπ^(+)π^(0))=(0.64±0.09±0.02)%,B(Λ_(c)^(+)→nπ^(+)π^(-)π^(+))=(0.45±0.07±0.03)%,and B(Λ_(c)^(+)→nK^(-)π^(+)π^(+))=(1.90±0.08±0.09)%,where the first uncertainties are statistical and the second are systematic.We find that the branching fraction of the decayΛ_(c)^(+)→nπ^(+)π^(0)is about one order of magnitude higher than that ofΛ_(c)^(+)→nπ^(+).

Measurements of the center-of-mass energies of e^(+)e^(-)collisions at BESIII

During the 2016-17 and 2018-19 running periods,the BESIII experiment collected 7.5 fb of e^(+)e^(-)collision data at center-of-mass energies ranging from 4.13 to 4.44 GeV.These data samples are primarily used for the study of excited charmonium and charmoniumlike states.By analyzing the di-muon process e^(+)e^(-)→(γISR=FSR)μ^(+)μ^(-),we measure the center-of-mass energies of the data samples with a precision of 0.6 MeV.Through a run-by-run study,we find that the center-of-mass energies were stable throughout most of the data-collection period.

Study of BESIII trigger efficiencies with the 2018 J/ψ data

Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.

Microstructure and Mechanical Properties of Fe-based Amorphous Composite Coatings Reinforced by Stainless Steel Powders

In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) spraying.The microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6L stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous phase.Bonding strength of coatings to the substrate was determined by 'pull-off' tensile tests.The results revealed that the31 6L stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous splats.The addition of31 6L stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.