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The Soochow University Beamline, located at the National Synchrotron Radiation Laboratory in China, is a Soft X-ray beamline designed for studying energy-related materials and devices. It operates in the energy range of 45 eV–1100 eV and is specifically tailored for investigating Li, B, C, N, O, F K-edges, and most L-edges of transition metals. The beamline offers various capabilities, including X-ray absorption, photon in photon out, and in situ/operando studies of energy materials and devices in gas/liquid environments. It has been successful in producing high-quality research papers and is open to users worldwide. The beamline is a collaborative effort between Soochow University and the National Synchrotron Radiation Laboratory, with funding from Soochow University. It is the first synchrotron radiation beamline in China to be funded by a university. [Extracted from the article]

Free electron LASer in Hamburg is the first free electron laser user facility operating in the vacuum ultraviolet and soft X-ray wavelength range. Many user experiments require knowledge of the spatial and temporal coherence properties of the radiation. In this paper, we present a theoretical analysis of the coherence properties of the radiation for the fundamental and for the higher odd frequency harmonics. We show that temporal and spatial coherence reach their maxima close to the free electron laser (FEL) saturation but may degrade significantly in the post-saturation regime. We also find that the pointing stability of short FEL pulses is limited due to the fact that nonazimuthal FEL eigenmodes are not sufficiently suppressed. We discuss possible ways for improving the degree of transverse coherence and the pointing stability. [ABSTRACT FROM AUTHOR]

Background: Asiaticoside (AS) is extracted from the traditional herbal medicine Centella asiatica, and has angiogenic, antioxidant, anti-inflammatory, and wound-healing effects. We investigated the effects of AS on skin flap survival. Methods: Dorsal McFarlane flaps were harvested from 36 rats and divided into two groups: an experimental group treated with 40 mg/kg AS administered orally once daily, and a control group administered normal saline in an identical manner. On day 2, superoxide dismutase (SOD) and malondialdehyde (MDA) levels, and production of the cytokines tumor necrosis factor-α and interleukin (IL)-6 were evaluated. On day 7, tissue slices were stained with hematoxylin and eosin. The expression of vascular endothelial growth factor (VEGF), IL-6, and IL-1β were immunohistochemically evaluated. Microcirculatory flow was measured using laser Doppler flowmetry. Flap angiography, using the lead oxide-gelatin injection technique, was performed with the aid of a soft X-ray machine. Results: The AS group exhibited greater mean flap survival area, improved microcirculatory flow, and higher expression levels of SOD and VEGF compared with the control group. However, MDA levels and the inflammatory response were significantly reduced. Conclusions: AS exhibits promise as a therapeutic option due to its effects on the viability and function of random skin flaps in rats. [ABSTRACT FROM AUTHOR]

Synchrotron radiation (SR)-based soft X-ray (SX) microspectroscopy has been applied as a promising analytical method to investigate architectural structures that comprise ceramic-tile/adhesive/mortar-structured composite materials. Microprobe X-ray fluorescence (µXRF) spectra, elemental distribution maps and microprobe near-edge X-ray absorption fine structure (µNEXAFS) spectra were observed near each interface in the composite materials using an SX-beam with a beam size of 1–2 µm full-width at half-maximum (FWHM). Elemental distribution maps for O, Na, Mg, Al, and Si were obtained to clearly visualize the interfaces of the composite materials with pixel sizes of 10 and 1 µm with the aid of line profile analyses. When the photon flux of the focused SX-beam reached approximately 8 × 108 ph/s, the critical dose time ( t dose c ) for the adhesive was estimated to be 30 min ( t dose c is the time at which the peak intensity of a specific chemical state in the µNEXAFS spectrum decreases to 1/e of the initial undamaged state due to radiation damage). We demonstrated the capability of the proposed method to survey local information regarding element-specific chemical states at the ceramic-tile/adhesive and adhesive/mortar interfaces before the adhesive is severely damaged due to the intense SX-beam. [ABSTRACT FROM AUTHOR]

The complex distribution of particle charge states resulting from neutralization processes by radioactive or soft X-ray charge neutralizers is a well-documented problem in aerosol science. Here, we demonstrate that non-idealities in the collection efficiency of an impactor allows for the transmission of an unexpected population of multiply charged particles by a differential mobility analyzer that can bias optical measurements. The extinction cross sections (Cext) of ammonium sulfate particles were quantified using cavity ring-down spectroscopy and particle counting. Particles were selected by electrical mobility (i.e., a metric of particle size) using a differential mobility analyzer (DMA) or electrical mobility and mass selected by a tandem DMA and aerosol particle mass analyzer (APM), respectively, to elucidate multiple charging artifacts. Measured Cext exhibited statistically significant differences at particle sizes near the impactor cut point implying that these multiply charged particles should not be present and could not be confirmed by parallel size distribution measurements. Additionally, comparison of Cext with Mie theory demonstrates that misclassification of the multiply charged particles can give rise to numerically accurate results. To understand these observations, the collection efficiency (CE) of four impactors from similar electrostatic classifiers was investigated. From these measurements, it was determined that the nominal and actual diameters of the impactors differed by −0.5% (457 μm vs. (455 ± 1) μm, respectively (uncertainty is 1σ standard deviation)) but the average Stk50 (the Stokes number at the cut-point, D50) values differed by ≈ 23% (0.23 vs. 0.18 ± 0.01, respectively). The measured CE as a function of √Stk (a metric of particle aerodynamic size) exhibits a long tail toward higher √Stk values, allowing for transmission of the larger and multiply charged particles observed in the optical measurements. These measurements highlight the utility of using orthogonal, spectroscopic methods to quantify the presence of multiply charged particles. Copyright © 2023 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

A wide range of advanced characterization tools has been exploited for energy issues. Soft X-ray emission spectroscopy (SXES) equipped with electron microscopy as an emerging analysis tool has made its debut in energy storage recently. The emergence of SXES provides powerful opportunities to explain the energy storage mechanisms, especially in the field of silicon-based anode for lithium-ion batteries. Herein, we summarize the SXES principles, development process and the unique advantages of SXES as well as coupling with other techniques. We further put forward our reasonable outlook for the development and application of SXES that will serve widely in materials science. This review pioneers a themed application of the emerging soft X-ray emission spectroscopy, herein mechanistic insight into lithium ion batteries. [ABSTRACT FROM AUTHOR]

A molecule with two or more atoms of the same element in distinct chemical environments is a trial system for probing site-specific fragmentation. In this context, special attention is deserved to 1,1,1,2-tetrafluoroethane (CF3CH2F), which has been the subject of numerous studies. This work discusses the effects of extreme ultraviolet (EUV) and soft X-ray irradiation on CF3CH2F from a dedicated translational kinetic energy release (KER) perspective. This analysis is achieved by evaluating the mean KER for its fragments at photon energies over 30–320 eV and computing the KER distribution (KERD) for the main fragments over the 282–320 eV range. The questions of interest from the point of view of the present study are twofold: (i) How do the mean KER of ionic fragments of the valence or core-excited CF3CH2F molecule change as a function of incident photon energy? (ii) Is there any evidence of site-specific or state-specific dissociation mechanisms in a molecule containing two carbon atoms in distinct chemical environments? From our results, lighter fragments showed to have their mean KER virtually following respective ion yields previously reported. And the overall learning is that the chemical environment associated with each C 1s excitation plays a role in differentiating the KER results. [ABSTRACT FROM AUTHOR]

In this study, experiments and simulations of Ne-like Ge soft X-ray lasers driven by nanosecond fundamental-frequency (1ω) and double-frequency (2ω) lasers are performed. The results show that 2ω lasers are also able to drive and produce Ne-like Ge soft X-ray lasers, even though the requirements for the driving conditions greatly increase compared to 1ω lasers. It is expected that the laser outputs at 23.2 and 23.6 nm will be stronger at higher power densities. The results provide a good foundation for executing experiments using Ne-like Ge soft X-ray lasers at existing large laser facilities, which cannot currently sustain 1ω drive lasers. [ABSTRACT FROM AUTHOR]

We present the results of a computer simulation study of the melting scenario of two-dimensional soft-disk systems with potential , n=12 and n=1024, both in the presence of random pinning and without it. The melting parameters have been determined from analysis of the behaviour of equations of state, correlation functions of the orientational and translational order parameters, Young modulus and renormalisation group equations. The transition points obtained from these criteria are in good agreement. We have shown that the systems melted in two stages – first-order hexatic phase to liquid transition and the continuous Berezinskii–Kosterlitz–Thouless type crystal-hexatic phase transition. Random pinning widened the hexatic phase, but left the melting scenario unchanged. [ABSTRACT FROM AUTHOR]

We extend our previous studies of stimulated Compton scattering (SCS) of X-ray [H. Bachau, M. Dondera and V. Florescu,Phys. Rev. Lett.2014, 112, 073001 and M. Dondera and V. Florescu, H. BachauPhys. Rev. A2014, 90, 033423] to the case of soft X-ray domain. We consider the ionization of the hydrogen atom interacting with a coherent superposition of two pulses in the frequency range of few hundreds of eV’s. We use the two theoretical approaches developed in previous works, i.e. the resolution of the time dependent Schrödinger equation and an approach based on perturbation theory. After a detailed analysis of the electron spectrum for15 a.u.,14 a.u., we mainly focus on SCS. We present photoelectron energy distributions, ionization rates and angular distributions at various relative directions of propagation of the pulses. SCS angular distributions are also shown for10 a.u.,9 a.u. Finally, we present new analytic formula, based on perturbation theory, describing SCS at threshold (a.u.), i.e. for zero final electron energy. [ABSTRACT FROM AUTHOR]

The fragmentation pattern of the iodine-containing moleculesandfollowing a strong multiphoton excitation in the vicinity of the iodine 4d giant resonance regime is studied using soft X-ray free electron laser radiation. A strong difference of the charge distribution and the kinetic energy release (KER) for the two molecules is found. The effects can be attributed to charge rearrangement processes induced by the photoexcitation. The difference in the observed distribution for higher charge states of iodine and carbon fragments is consistent with an over-the-barrier model for the charge rearrangement in the dissociating molecules. The KER for singly ionised carbon fragments indicates an ultrafast charge rearrangement before the dissociation starts. [ABSTRACT FROM AUTHOR]

I August 31, 2021, marked the 200th birthday of Hermann von Helmholtz, remarkable physicist, passionate mathematician, and research visionary. He would have supported the planning of a successor source of BESSY II - at least, that is what he said when he came for tea to celebrate his special birthday in Berlin-Adlershof.n (© Camera Medica/HZB). [Extracted from the article]

Wolfgang Drube DESY, Hamburg, Germany Mustafa Fatih Genisel SESAME, Allan, Jordan Andrea Lausi SESAME, Allan, Jordan Andrea.Lausi@sesame.org.jo References 1 Helmholtz-Sesame Soft X-ray Beamline HESEB. http://heseb.desy.de 2 SESAME, Beamlines. https://www.sesame.org.jo/beamlines On January 9, 2022, the installation of HESEB, the Helmholtz-SESAME Beamline for soft X-ray spectroscopies [[1]], started at SESAME in Jordan. [Extracted from the article]