[en] Swift observations revealed interesting but puzzling afterglow behaviors that demand a rethinking of the origins of GRBs and their afterglows. In general, the observed X-ray afterglows include the contributions from both the external shock emission and late 'internal' emission due to extended central engine activities. Recent observations and some theoretical efforts to interpret the data are highlighted. The high energy spectral regime will be fully revealed thanks to the launch and operation of several space and ground-based high energy detectors. Various physical processes that are predicted to contribute to high energy emission from GRBs are summarized, with comments on the most probable mechanisms of high energy emission in both the prompt and the afterglow phases

[en] A simple processing of preparing broadband anti-reflective single-layer silica films is presented in this article. By adding polyvinylpyrrolidone (PVP) into reactant mixture, PVP-containing SiO₂ sol was obtained under base catalyzed hydrolysis and condensation of tetraethoxysilane. The spin-coating films and the dip-coating films were deposited on one side and two sides of quartz substrates. The anti-reflection band is 315 nm wide for dip-coating film and 559 nm wide for spin-coating film and the transmittance reached to 99.95 and 95.92% for dip-coating film and spin-coating film, respectively. By a Nd:YAG lasers the laser damage threshold of as-deposited films was measured at 1064 nm wavelength (1 ns pulse). It ranged from 24 to 33 J/cm² with an average of 28.7 J/cm². Compared to SiO₂ sol without PVP, not only was the anti-reflection band broadened but the anti-reflection and laser damage threshold were retained

[en] Highlights: • We report a new oxidase mimetic system for highly efficient electrochemical immunoassay. • NiCoBP-doped carbon nanotube hybrids were used as the nanocatalysts. • NiCoBP-doped carbon nanotube hybrids were used as the mimic oxidase. - Abstract: NiCoBP-doped multi-walled carbon nanotube (NiCoBP–MWCNT) was first synthesized by using induced electroless-plating method and functionalized with the biomolecules for highly efficient electrochemical immunoassay of prostate-specific antigen (PSA, used as a model analyte). We discovered that the as-synthesized NiCoBP–MWCNT had the ability to catalyze the glucose oxidization with a stable and well-defined redox peak. The catalytic current increased with the increment of the immobilized NiCoBP–MWCNT on the electrode. Transmission electron microscope (TEM) and energy dispersive X-ray spectrometry (EDX) were employed to characterize the as-prepared NiCoBP–MWCNT. Using the NiCoBP–MWCNT-conjugated anti-PSA antibody as the signal-transduction tag, a new enzyme-free electrochemical immunoassay protocol could be designed for the detection of target PSA on the capture antibody-functionalized immunosensing interface. Experimental results revealed that the designed immunoassay system could exhibit good electrochemical responses toward target PSA, and allowed the detection of PSA at a concentration as low as 0.035 ng mL⁻¹. More importantly, the NiCoBP-MWCNT-based oxidase mimetic system could be further extended for the monitoring of other low-abundance proteins or disease-related biomarkers by tuning the target antibody

[en] Double neutron star mergers are strong sources of gravitational waves. The upcoming advanced gravitational wave detectors are expected to make the first detection of gravitational wave bursts (GWBs) associated with these sources. Proposed electromagnetic counterparts of a GWB include a short gamma-ray burst, an optical macronova, and a long-lasting radio afterglow. Here we suggest that at least some GWBs could be followed by an early afterglow lasting for thousands of seconds, if the post-merger product is a highly magnetized, rapidly rotating, massive neutron star rather than a black hole. This afterglow is powered by dissipation of a proto-magnetar wind. The X-ray flux is estimated to be as bright as (10^–8-10^–7) erg s^–1 cm^–2. The optical flux is subject to large uncertainties but could be as bright as 17th magnitude in R band. We provide observational hints of such a scenario, and discuss the challenge and strategy to detect these signals.

[en] In this paper, the circulating cooling water system of nuclear power plants (NPP) in United States is summarized, and the operation practices of different cooling water systems, such as once-through, natural and mechanical draft cooling tower, cooling pond, and mixed cooling mode, used by several coastal and inland NPPs are given. Also, based on the related experiences, some suggestions for use of cooling water system in China NPPs are presented. (authors)

[en] The electron beam welding (EBW) of 304 stainless steel to QCr0.8 copper alloy with or without copper filler wire was studied in detail. The temperature fields and magnitude and distribution of stress fields in the joints during the welding process were numerically simulated using finite element method. The temperature cycles and residual stresses were also experimentally measured by thermometric and hole-drilling methods, respectively. The accuracy of the modeling procedure was verified by the good agreement between the calculated results and experimental data. The temperature distribution in the joint was found to be asymmetric along the center of weld. In particular, the temperature in the copper alloy plate is much higher than that in the 304 SS plate owing to the great difference in thermal conductivity between the two materials. The peak three-dimensional residual stresses all appeared at the interface between the copper and steel in the two different joints. Furthermore, the weld was subjected to tensile stress. The longitudinal residual stress, generally the most harmful to the integrity of the structure among the stress components in EBW with filler wire (EBFW), was 53 MPa lower than that of autogenous EBW (AEBW), and the through-thickness residual stress was 12 MPa lower. The transverse residual stress of EBFW was 44 MPa higher than that of AEBW. However, analysis of the von Mises stress showed that the EBFW process effectively reduced the extent of the high residual stress region in the weld location and the magnitude of the residual stresses in the copper side compared with those of the AEBW joint. - Highlights: • Copper and steel was welded by electron beam welding with copper filler wire. • The copper wire fed into gap can reduce the peak value of residual stress. • The peak value of longitudinal stress can be reduced 53 MPa by the filler wire. • The range of nov Mises stress in the weld could be reduced by the wire

[en] Axial distribution of activity ratio A(¹³⁴Cs)/A(¹³⁷Cs) along the fuel rod with different burnup level, irradiation history and cooling time is measured by the γ-scanning device. As a comparison, this distribution is calculated by the FCAC code used for the fuel rod failure analysis. The calculated values are in agreement with the measured values within a deviation of 12%

[en] We consider a relativistic spherical shell and calculate its spectral flux as received by a distant observer. Using two different methods, we derive a simple analytical expression of the observed spectral flux and show that the well-known relation $\stackrel{^<!--\; ^\; -->}{\mathrm{\alpha <!--\; ??\; -->}}=2+\stackrel{^<!--\; ^\; -->}{\mathrm{\beta <!--\; ??\; -->}}$ (between temporal index $\stackrel{^<!--\; ^\; -->}{\mathrm{\alpha <!--\; ??\; -->}}$ and spectral index $\stackrel{^<!--\; ^\; -->}{\mathrm{\beta <!--\; ??\; -->}}$) of the high-latitude emission is naturally achieved in our derivation but holds only when the shell moves with a constant Lorentz factor Γ. Presenting numerical models in which the shell is undergoing acceleration or deceleration, we show that the simple $\stackrel{^<!--\; ^\; -->}{\mathrm{\alpha <!--\; ??\; -->}}=2+\stackrel{^<!--\; ^\; -->}{\mathrm{\beta <!--\; ??\; -->}}$ relation does indeed deviate as long as Γ is not constant. For the models under acceleration, we find that the light curves produced purely by the high-latitude emission initially exhibit much steeper decay than in the constant Γ case and gradually resume the $\stackrel{^<!--\; ^\; -->}{\mathrm{\alpha <!--\; ??\; -->}}=2+\stackrel{^<!--\; ^\; -->}{\mathrm{\beta <!--\; ??\; -->}}$ relation in about one and a half orders of magnitude in observer time. For the models under deceleration, the trend is opposite. The light curves made purely by the high-latitude emission initially exhibit a shallower decay than in the constant Γ case and gradually resume the relation $\stackrel{^<!--\; ^\; -->}{\mathrm{\alpha <!--\; ??\; -->}}=2+\stackrel{^<!--\; ^\; -->}{\mathrm{\beta <!--\; ??\; -->}}$ in a similar order of magnitude in observer time. We also show that how fast the Lorentz factor Γ of the shell increases or decreases is the main ingredient determining the initial steepness or shallowness of the light curves.

[en] The physical nature of fast radio bursts (FRBs), a new type of cosmological transient discovered recently, is not known. It has been suggested that FRBs can be produced when a spinning supra-massive neutron star loses centrifugal support and collapses to a black hole. Here, we suggest that such implosions can happen in supra-massive neutron stars shortly (hundreds to thousands of seconds) after their births, and an observational signature of such implosions may have been observed in the X-ray afterglows of some long and short gamma-ray bursts (GRBs). Within this picture, a small fraction of FRBs would be physically connected to GRBs. We discuss possible multi-wavelength electromagnetic signals and gravitational wave signals that might be associated with FRBs, and propose an observational campaign to unveil the physical nature of FRBs. In particular, we strongly encourage a rapid radio follow-up observation of GRBs starting from 100 s after a GRB trigger

[en] Objective: To investigate the level of serum Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) and its significance in patients with myelodysplastic syndrome (MDS). Methods: 35 controls and 32 MDS patients were tested. The level of serum GM-CSF was determined with RIA. Results: The level of serum GM-CSF was 54.86 ± 17.01 pg/ml in the controls; 30.65 ± 11.2 pg/ml in the 16 MDS patients of the RA type; 34.80 ± 15.8 pg/ml in the 15 MDS patients of the RAEB type. There was significant difference between level of the MDS RA type and controls (p < 0.01). The same was with the MDS RAEB type (p < 0.01). In a single patient of RAEBt type, the serum GM-CSF level was 90.6 pg/ml. Conclusion: The serum levels of GM-CSF were much lower in MDS patients than those in the controls. GM-CSF might play a role in the pathogenesis of the disease