Luminescent carbon nanodots (CDs) are attracting great interests due to their unique properties in physics and chemistry. In this study we present the experimental evidences of the significant roles ...of self–absorption and radiative energy transfer in the photoluminescence process of N–doped CDs in water. It is found that the PL spectra, especially the relative intensity between the UV and visible bands, which are the major spectral structures, show a distinctive dependence on the concentrations of CDs, and can be well understood with the well–known Beer–Lambert law. These findings could be very helpful to deepen the existing understanding of the complex luminescence mechanisms of CDs.
Abstract
A novel 3-D calorimeter, composed of about 7500 LYSO cubes, is the key and crucial detector of the High Energy cosmic-Radiation Detection (HERD) facility to be installed onboard the China ...Space Station. Energy deposition from cosmic ray in each LYSO cube is translated by multiple wavelength shifting (WLS) fibers for multi-range data acquisition and real-time triggering.
In this study, various methods of surface finish and encapsulation of the LYSO cube were investigated to optimize the amplitude from the WLS fiber end with the aim of improving the signal-to-noise ratio of Intensified scientific CMOS (IsCMOS) collection. The LYSO cube with five rough surfaces and a specular reflector achieves the maximum amplitude at the low-range fiber end, which is increased by roughly 44% compared to the polished cube with PTFE wrapping.
The non-uniformity of amplitude at different positions on the LYSO cube surface was measured by X-ray and the positional correlation factor was derived for the entire cube. A simulation based on HERD CALO was conducted, which revealed that both the LYSO cube with five rough surfaces and the cube with rough bottom face exhibit superior energy resolution for electrons compared to the other two configurations.
The back-streaming neutrons (back-n) is a white neutron experimental facility at the China spallation neutron source (CSNS). The time structure of the primary proton beam makes it fully applicable to ...use the time-of-flight (TOF) method for neutron energy measuring. We implemented the electronics of TOF measurement on the general-purpose readout electronics designed for all the seven detectors in back-n. The electronics are based on the peripheral component interconnect express eXtensions for instrumentation (PXIe) platform, which is composed of field digitizer modules (FDM), trigger and clock modules (TCM), and signal conditioning modules. The T0 signal synchronous to the CSNS accelerator represents the neutron emission from the target. It is the start of the time stamp. The TCM receives, synchronizes, and distributes the T0 signal to each FDM based on the PXIe backplane bus. Meanwhile, the detector signals, after being conditioned, are fed into FDMs for waveform digitizing. The first sample point of the signal waveform is the stop of the time stamp. According to the time stamp and the time of the signal over the threshold, the total TOF can be obtained. The time-to-digital converter (TDC) based on field-programmable gate array (FPGA) is implemented on the TCM to accurately acquire the time interval between the asynchronous T0 signal and the global synchronous clock phase. There is also an FPGA-based TDC on the FDM to accurately acquire the time interval between the T0 signal arriving at the FDM and the first sample point of the signal waveform. The over-threshold time of signal is obtained offline. This method for TOF measurement is efficient and not needed for additional modules. Test results showed that the accuracy of TOF is subnanosecond and can meet the requirement for back-n at the CSNS.
Summary
Corynespora cassiicola is a plant pathogen associated with leaf‐spotting disease. The fungus has been found on diverse substrates: leaves, stems and roots of plants; nematode cysts and human ...skin. It rarely causes human infections. Here we report one case of subcutaneous phaeohyphomycosis caused by C. cassiicola with prominent tissue necrosis in a woman. All of her clinical features pointed towards a genetic linkage. Hence, whole‐exome sequencing and Sanger sequencing were performed on this patient. One mutation of CARD9 was detected.
What's already known about this topic?
Cases of phaeohyphomycosis caused by Corynespora cassiicola are rare.
Genetic susceptibility to fungal diseases in otherwise healthy patients has gained interest in recent years.
In particular, various inborn errors of genes have been reported to underlie chronic mucocutaneous candidiasis disease and other cutaneous dermatophytoses.
What does this study add?
We present a female patient with phaeohyphomycosis caused by C. cassiicola with prominent tissue necrosis.
Molecular evidence of mutation in CARD9 is provided for C. cassiicola infection.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Back-streaming neutrons through the incoming proton channel at the spallation target station of China Spallation Neutron Source (CSNS) has been exploited as a white neutron beam line (so-called ...Back-n), and a number of spectrometers for nuclear data measurements have been planned. With a thick tungsten target and modest moderation by the cooling water through the target slices, the neutron beam is very intense which is in the order of 5.0×106 n/cm2/s at 80 m from the target and has an excellent energy spectrum spanning from 1 eV to 100 MeV. In addition, the time structure of the primary proton beam under different accelerator operation modes is fully applicable for time-of-flight measurements. Altogether, it makes the CSNS Back-n very much suitable for nuclear data measurements. The construction of the neutron beam line and five of the seven planned spectrometers are under way. It is expected that the first batch experiments be carried out from late 2017, when CSNS starts commissioning.
Magnetism in layered two dimensional materials has attracted extensive interest. In this work, a variety of concentrations of Co dopants (1, 2 and 4 at.%) were doped into MoTe2 single crystal by ion ...implantation. Magnetic results indicate that pure MoTe2 displays a diamagnetic behavior. A small amount of Co doping induces a very high saturation magnetization. 4 % Co doping exhibits a saturation magnetization as high as 2231 emu/cm3, higher than pure metallic Fe (1958 emu/cm3). In addition, an outsized coercivity of 11 kOe was also detected in the 2 at.% Co doped MoTe2 sample, which may be a consequence of doping-induced defects in the lattice structure, stress, anisotropic geometry of Co-Te ions and pinning effects by the defects in-between the ions. First principles density functional theory calculations reveal that doping-induced structural defects, including substitutional and interstitial Co, nanoholes as well as interstitial Mo, are responsible for the high magnetization.
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•Successful doping of Co into MoTe2.•Achieving high magnetization.•Achieving high coercvity.•Understanding the mechanisms of high coercivity and magnetization by calculations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Back-n white neutron source at China Spallation Neutron Source (CSNS) is designed specifically for nuclear data measurements and multidisciplinary neutron applications. The time of flight (TOF) ...method is deployed to obtain a high resolution of neutron energy. In the normal operation mode of CSNS there are two proton bunches with a time interval of 410 ns in each pulse which has a repetition frequency of 25 Hz. Due to the superposition of the event distributions corresponding to two bunches, the resolution of the TOF measurement at Back-n will be degraded by the double-bunch characteristics if the measured event distribution is used directly without unfolding, especially in the higher neutron energy region. To nearly recover the event distribution corresponding to a single proton bunch, the unfolding methods have been developed to obtain better time resolution and energy resolution. Two kinds of unfolding algorithms based on the iterative Bayesian method and the iterative event re-distribution method, respectively, have been developed and tested with simulated data and experimental data. The developed methods have shown nice performance in unfolding the double-bunch event distributions with high accuracy and fast convergence. With the deploying of the unfolding methods, the data of the first batch experiments conducted at Back-n in the normal double-bunch mode were analyzed and nearly the same time resolution as in the case of the single-bunch mode has been obtained.
•Enhanced heat transfer in partitioned Rayleigh-Bénard convection (PRBC) is simulated.•Heat transfer in PRBC is enhanced by a laminar jet flow in the space between plates.•Thermosiphoning and RB ...convection jointly determine the convection flow of PRBC.•Optimal geometry for maximum heat transfer is predicted and validated by data.•Geometry-dependence of Nu is predicted by the model, useful for engineering design.
It was recently discovered that a partitioned Rayleigh-Bénard convection (PRBC) by vertical adiabatic boards leaving a narrow horizontal channel (HC) open between partition boards and the cooling/heating plates, may remarkably enhance the overall heat transfer (Bao et al., 2015). This phenomenon is thoroughly investigated by both numerical and analytic study. Numerically, we perform a series of two-dimensional (2-D) direct numerical simulations (DNS) of PRBC for the same set of Rayleigh and Prandtl numbers (Ra=1×108,Pr=0.7and5.3) and two aspect ratios (Γ=1 and 5). The DNS confirm that when the number of partition boards n is large enough, the flow in PRBC becomes coherent and laminar, and the wall jet in HC forms a thinner thermal boundary layer and hence enhances the heat flux from/to conducting plates. A thermosiphoning mode (TS-mode) is used to characterize this laminar forced convection state, which yields an analytic description of the relation between geometrical parameters and the heat transfer coefficient, including two asymptotes for small and large board-to-plate spacing d, where the Nusselt number (Nu) varies with d as d3 and d-1, respectively. The analytical model then predicts an optimal partition spacing maximizing the heat transport, in good agreement with the DNS. More interestingly, the model yields an optimal width of the vertical channel (VC) between two partition boards, in the range 0.01⩽s/H⩽1.00 for Γ=1, as also validated by DNS. For large VC width, we develop a convection-adaptive (CA) model describing the interplay between turbulent bulk flow in VC and the TS-mode, which yields a prediction of Nu in close agreement with DNS for a wide range of n (n=0–35 for Γ=5). Therefore, we have developed an analytic understanding of the PRBC enhanced heat transfer, which provides useful relations for engineering design in industrial applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Global particle simulations of the lower hybrid (LH) waves have been carried out using fully kinetic ions and drift kinetic electrons with a realistic electron-to-ion mass ratio. The LH wave ...frequency, mode structure, and electron Landau damping from the electrostatic simulations agree very well with the analytic theory. Linear simulation of the propagation of a LH wave-packet in the toroidal geometry shows that the wave propagates faster in the high field side than the low field side, in agreement with a ray tracing calculation. This poloidal asymmetry arises from the non-conservation of the poloidal mode number due to the non-uniform magnetic field. In contrast, the poloidal mode number is conserved in the cylindrical geometry with the uniform magnetic field.
Summary
The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We ...aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large‐sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)‐positive chronic HBV infection (n = 588), HBeAg‐positive chronic hepatitis B (n = 596), and HBeAg‐negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL 10%‐90% confidence interval: 3.52 log10 IU/mL‐4.99 log10 IU/mL) in patients with HBeAg‐positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg‐positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg‐negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg‐positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg‐negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
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