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HighlightsThe CuS@rGO composite aerogel can achieve the broad effective absorption bandwidth (EAB) of 8.44 GHz with the filler content of 6 wt%.The RLmin of CuS@rGO composite aerogel is -55.1 dB and EAB is 7.2 GHz with the filler content of 2 wt% by ascorbic acid thermal reduction. The radar cross-section reduction value of CuS@rGO composite aerogel can reach 53.3 dB m2.The CuS@rGO composite aerogels possess lightweight, compression and recovery, radar-infrared compatible stealth properties. Developing ultrabroad radar-infrared compatible stealth materials has turned into a research hotspot, which is still a problem to be solved. Herein, the copper sulfide wrapped by reduced graphene oxide to obtain three-dimensional (3D) porous network composite aerogels (CuS@rGO) were synthesized via thermal reduction ways (hydrothermal, ascorbic acid reduction) and freeze-drying strategy. It was discovered that the phase components (rGO and CuS phases) and micro/nano structure (microporous and nanosheet) were well-modified by modulating the additive amounts of CuS and changing the reduction ways, which resulted in the variation of the pore structure, defects, complex permittivity, microwave absorption, radar cross section (RCS) reduction value and infrared (IR) emissivity. Notably, the obtained CuS@rGO aerogels with a single dielectric loss type can achieve an ultrabroad bandwidth of 8.44 GHz at 2.8 mm with the low filler content of 6 wt% by a hydrothermal method. Besides, the composite aerogel via the ascorbic acid reduction realizes the minimum reflection loss (RLmin) of − 60.3 dB with the lower filler content of 2 wt%. The RCS reduction value can reach 53.3 dB m2, which effectively reduces the probability of the target being detected by the radar detector. Furthermore, the laminated porous architecture and multicomponent endowed composite aerogels with thermal insulation and IR stealth versatility. Thus, this work offers a facile method to design and develop porous rGO-based composite aerogel absorbers with radar-IR compatible stealth.

The cross section measurement of 144Sm (p, γ) 145Eu has been carried out around proton energies 2.6–6.8 MeV using the activation technique. Measured cross sections are compared with the previous measurement and theoretical predictions using TALYS 1.96. The molecular deposition method was used to prepare the enriched 144Sm targets of thickness 100–350 μg/cm2 on Al backing.

(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image).A combination is presented of all inclusive deep inelastic cross sections previously published by the H1 and ZEUS collaborations at HERA for neutral and charged current ... scattering for zero beam polarisation. The data were taken at proton beam energies of 920, 820, 575 and 460 GeV and an electron beam energy of 27.5 GeV. The data correspond to an integrated luminosity of about 1 fb... and span six orders of magnitude in negative four-momentum-transfer squared, ..., and Bjorken x. The correlations of the systematic uncertainties were evaluated and taken into account for the combination. The combined cross sections were input to QCD analyses at leading order, next-to-leading order and at next-to-next-to-leading order, providing a new set of parton distribution functions, called HERAPDF2.0. In addition to the experimental uncertainties, model and parameterisation uncertainties were assessed for these parton distribution functions. Variants of HERAPDF2.0 with an alternative gluon parameterisation, HERAPDF2.0AG, and using fixed-flavour-number schemes, HERAPDF2.0FF, are presented. The analysis was extended by including HERA data on charm and jet production, resulting in the variant HERAPDF2.0Jets. The inclusion of jet-production cross sections made a simultaneous determination of these parton distributions and the strong coupling constant possible, resulting in ... An extraction of ... and results on electroweak unification and scaling violations are also presented.

19F(p,α) reactions are important both in nuclear astrophysical field and for the study of the inner structure and the cluster behaviour in light nuclei. The available cross section data on such reaction, although being in reasonable agreement over a wide energy range, still show some discrepancies for both α0 and απ channels. In this work we discuss the preliminary results of a new experiment aimed to solve the disagreement around 1.6 MeV for the 19F(p,α0) absolute cross section. The excellent resolution of the detection device allowed us also to resolve the απ peak in the spectra obtained in the 1.0-1.5 MeV beam energy range, where very few data where previously reported in the literature.

A bstract We calculate the cross-sections for the radiative formation of bound states by dark matter whose interactions are described in the non-relativistic regime by a Yukawa potential. These cross-sections are important for cosmological and phenomenological studies of dark matter with long-range interactions, residing in a hidden sector, as well as for TeV-scale WIMP dark matter. We provide the leading-order contributions to the cross-sections for the dominant capture processes occurring via emission of a vector or a scalar boson. We offer a detailed inspection of their features, including their velocity dependence within and outside the Coulomb regime, and their resonance structure. For pairs of annihilating particles, we compare bound-state formation with annihilation.

The architectural design and fabrication of low-cost and reliable organic X-ray imaging scintillators with high light yield, ultralow detection limits and excellent imaging resolution is becoming one of the most attractive research directions for chemists, materials scientists, physicists and engineers due to the devices’ promising scientific and applied technological implications. However, the optimal balance among X-ray absorption capability, exciton utilization efficiency and photoluminescence quantum yield of organic scintillation materials is extremely difficult to achieve because of several competitive non-radiative processes, including intersystem crossing and internal conversion. Here we introduced heavy atoms (Cl, Br and I) into thermally activated delayed fluorescence (TADF) chromophores to significantly increase their X-ray absorption cross-section and maintaining their unique TADF properties and high photoluminescence quantum yield. The X-ray imaging screens fabricated using TADF-Br chromophores exhibited highly improved X-ray sensitivity and imaging resolution compared with the TADF-H counterpart. More importantly, the high X-ray imaging resolution of >18.0 line pairs per millimetre achieved from the TADF-Br screen exceeds most reported organic and conventional inorganic scintillators. This study could help revive research on organic X-ray imaging scintillators and pave the way towards exciting applications for radiology and security screening.Heavy atoms like Cl, Br and I introduced into thermally activated delayed fluorescence chromophores can increase the X-ray absorption cross-section. Light yield of ~20,000 photons MeV–1, detection limit of 45.5 nGy s−1 and imaging resolution of >18.0 line pairs per millimetre is demonstrated.

A bstract Thermal production of light dark matter with sub-GeV scale mass can be attributed to 3 → 2 self-annihilation processes. We consider the thermal average for annihilation cross sections of dark matter at 3 → 2 and general higher-order interactions. A correct thermal average for initial dark matter particles is important, in particular, for annihilation cross sections with overall velocity dependence and/or resonance poles. We apply our general results to benchmark models for SIMP dark matter and discuss the effects of the resonance pole in determining the relic density.

Canonical objects with known radar cross section (RCS), for example, the trihedral corner reflector (TCR), play a crucial role in the calibration of automotive radar sensors. Moreover, these canonical objects are also used in the validation of simulated RCS obtained using asymptotic methods, such as hybrid geometric optics (GO) and the physical optics (PO) based methods. However, accurate RCS prediction with asymptotic methods is highly dependent on the individual scattering mechanisms considered in a simulation, for example reflection and diffraction from the TCR surfaces and edges, respectively. Reliable measurements are therefore required to evaluate if a particular interaction mechanism can be neglected to reduce computation complexity without adversely affecting the accuracy of the predicted RCS. In this letter, the monostatic scattering characteristics of three metallic TCRs are investigated with varying geometrical sizes in the E‐band, that is, from 60 GHz to 90 GHz. The ultra‐wideband (UWB) measurements, which offer a high delay resolution, can enable the identification of the individual scattering mechanisms. Diffraction from the TCR edges is experimentally demonstrated to contribute to a non‐negligible scattered power in this frequency band. The TCR is an important canonical object for radar cross section (RCS) simulation validation as well as calibration of radar sensors. In the literature, measurement‐based characterization of the RCS of the TCR are scarce in the E‐band despite the important application like radar sensors simulation validation for autonomous driving. We demonstrate experimentally the contribution of reflected waves and diffracted waves in the E‐band for the metallic TCR.

A bstract We present the most precise value for the Higgs boson cross-section in the gluon-fusion production mode at the LHC. Our result is based on a perturbative expansion through N 3 LO in QCD, in an effective theory where the top-quark is assumed to be infinitely heavy, while all other Standard Model quarks are massless. We combine this result with QCD corrections to the cross-section where all finite quark-mass effects are included exactly through NLO. In addition, electroweak corrections and the first corrections in the inverse mass of the top-quark are incorporated at three loops. We also investigate the effects of threshold resummation, both in the traditional QCD framework and following a SCET approach, which resums a class of π 2 contributions to all orders. We assess the uncertainty of the cross-section from missing higher-order corrections due to both perturbative QCD effects beyond N 3 LO and unknown mixed QCD-electroweak effects. In addition, we determine the sensitivity of the cross-section to the choice of parton distribution function (PDF) sets and to the parametric uncertainty in the strong coupling constant and quark masses. For a Higgs mass of m H = 125 GeV and an LHC center-of-mass energy of 13 TeV, our best prediction for the gluon fusion cross-section is σ = 48.58 p b − 3.27 p b + 2.22 p b theory ± 1.56 p b 3.20 % P D F + α s .

IceCube has measured the absorption of atmospheric and astrophysical neutrinos in the Earth, and found that the interaction cross-section of multi-TeV neutrinos is within 50 per cent of the predictions of the standard model. Energetic neutrinos at the cross-section Neutrinos interact weakly with normal matter, but the neutrino–nucleon interaction cross-section gets larger with increasing neutrino energy. Hitherto, the cross-section has been measured only at relatively low energies. Spencer Klein and colleagues in the IceCube Collaboration report a measurement of neutrino absorption by the Earth at energies between 6.3 and 980 teraelectronvolts (TeV). The calculated cross-section is statistically consistent with that predicted by the standard model of particle physics, with no evidence for effects of compact dimensions. Neutrinos interact only very weakly, so they are extremely penetrating. The theoretical neutrino–nucleon interaction cross-section, however, increases with increasing neutrino energy, and neutrinos with energies above 40 teraelectronvolts (TeV) are expected to be absorbed as they pass through the Earth. Experimentally, the cross-section has been determined only at the relatively low energies (below 0.4 TeV) that are available at neutrino beams from accelerators 1 , 2 . Here we report a measurement of neutrino absorption by the Earth using a sample of 10,784 energetic upward-going neutrino-induced muons. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the neutrino–nucleon interaction cross-section for neutrino energies 6.3–980 TeV, more than an order of magnitude higher than previous measurements. The measured cross-section is about 1.3 times the prediction of the standard model 3 , consistent with the expectations for charged- and neutral-current interactions. We do not observe a large increase in the cross-section with neutrino energy, in contrast with the predictions of some theoretical models, including those invoking more compact spatial dimensions 4 or the production of leptoquarks 5 . This cross-section measurement can be used to set limits on the existence of some hypothesized beyond-standard-model particles, including leptoquarks.