[en] The two photon processes with one electric dipole photon and another electric quadrupole photon are investigated. These processes with selection rules different from two-electric dipole photon process may be tested by experiments with high power lasers. (author). 3 refs, 2 figs

[en] In this paper, using a quantum mechanical technique and introducing the so-called V representation (where the representation transformation is made by using the potential Hamiltonian V), we studied x-ray propagation in a linear plasma medium both analytically and numerically. A modified relation between the phase of the probe and the reference light and the electron density of the plasma is derived, in which the contribution of the gradient of the electron density has been taken into account. It is shown that this relation has the advantage in measurements of the electron density of a plasma using the x-ray interferometry technique of lessening the errors originating from the electron density gradient. The validity of x-ray interferometry is discussed in both mathematical and physical terms

[en] Highlights: • A LES-VOF model is conducted to simulate atomization of coaxial swirling jets. • Structure and flow field of coaxial swirling jets are investigated. • Merging process occurs at the nozzle exit and generates additional perturbation. • The Rayleigh mode instability dominates the breakup of ligaments. - Abstract: Spray atomization process of a liquid-liquid coaxial swirl injector in bipropellant thruster has been investigated using volume of fluid (VOF) method coupled with large eddy simulation methodology. With fine grid resolution, detailed flow field of interacted liquid sheet has been captured and analyzed. For coaxial swirling jet, static pressure drop in the region between the liquid sheets makes two liquid sheets to approach each other and merge. A strong pressure, velocity and turbulent fluctuations are calculated near the contact position of two coaxial jets. Simulation results indicate that additional perturbations are generated due to strong radial and axial shear effects between coaxial jets. Observation of droplet formation process reveals that the Rayleigh mode instability dominates the breakup of the ligament. Droplet diameter and distribution have been investigated quantitatively. The mean diameter of the coaxial jets is between that of the inner and the outer jets. Compared with the individual swirling jets, wider size distributions of droplets are produced in the coaxial jets.

[en] Hydrate-based technology has been developing for decades to meet the demands in industrial applications. With the global demands for reduced carbon dioxide (CO_2) emissions and more fresh water, CHBD (CO_2hydrate-based desalination) was proposed and has developed rapidly. In this study, to provide basic data for the improvement of CHBD, the thermodynamic and kinetic characteristics of CO_2and propane (C_3H_8) mixed-gas hydrates in salt solution were experimentally investigated in which C_3H_8was chosen as the hydrate formation promoter. We studied nine experimental cases (54 cycles) with different C_3H_8proportions (ranging from 0 to 13%) and different initial solution saturations (30%, 40% and 50%). The hydrate phase equilibrium data were generated using the isochoric method, and the hydrate formation saturations were calculated using the relative gas uptake equation. The results indicated that the increase in the C_3H_8proportion significantly decreases the gas mixture hydrate equilibrium pressure. Additionally, the relative gas uptake was reduced as the C_3H_8proportion increased. A lower relative gas uptake was obtained at a lower gas pressure for the same gas mixture. The initial solution saturation exhibited an insignificant effect on the hydrate phase equilibrium conditions. When the initial solution saturations increased from 30% to 50%, the relative gas uptake decreased. - Highlights: • C_3H_8 improves the thermodynamics and kinetics of CO_2 hydrates formation. • Hydrates equilibrium pressure decreases with the increase of C_3H_8 proportion. • Higher C_3H_8 proportion and/or solution saturation decrease relative gas uptake. • Initial pressure and solution saturation has interactive effect on gas uptake.

[en] In normal metals, macroscopic properties are understood using the concept of quasiparticles. In the cuprate high-temperature superconductors, the metallic state above the highest transition temperature is anomalous and is known as the “strange metal.” We studied this state using angle-resolved photoemission spectroscopy. With increasing doping across a temperature-independent critical value p_c~ 0.19, we observed that near the Brillouin zone boundary, the strange metal, characterized by an incoherent spectral function, abruptly reconstructs into a more conventional metal with quasiparticles. Above the temperature of superconducting fluctuations, we found that the pseudogap also discontinuously collapses at the very same value of p_c. These observations suggest that the incoherent strange metal is a distinct state and a prerequisite for the pseudogap; such findings are incompatible with existing pseudogap quantum critical point scenarios.

[en] Misalignment is one of the common welding defects in melt welding, which can lead to local stress in weld and affect the quality of equipment. When the misalignment is large, it must be treated and the necessary evaluation of the treatment results must be made. As the main component of reactor internals, the manufacturing quality of Nuclear Cylinder Reactor Internals is directly related to the safety of NPP's operation. In the manufacturing process of Nuclear Cylinder Reactor Internals of a NPP, the welding has the misalignment which reaches about 10 mm (welding seam is about 52 mm thick), which cannot meet the design requirements and seriously affects the quality of equipment. In order to reduce the local stress concentration and improve the mechanical properties, the dislocation defect of the weld seam was treated technically. The mechanical properties of the treated Nuclear Cylinder Reactor Internals were quantitatively analyzed by using the finite element model, which met the requirements of the original design code. (authors)

[en] The operating head of the fast reactor fuel assembly plays an important role in balancing pressure, moderating pressure drop and reducing vibration, which has a significant impact on the safety of fast reactor. Furthermore, it has the function of fixing and snatching during the process of replacing and hoisting fuel assembly. At present, there is no uniform design standard of the operating head. In this study, the computational fluid dynamics (CFD) was used to investigate the flow characteristics of the closed and open operating head. The results show that the outlet hole at the top of the operating head can effectively balance the pressure inside the operating head, moderate the pressure drop and reduce the vibration to avoid harmful impact on the structure. In addition, with the increase of outlet-hole diameter, the flow performance has been significantly improved inside the open operating head, which enhances the heat transfer and avoids the potential safety risks caused by heat accumulation. Moreover, it is suggested that the structure design of fast reactor fuel assembly can be optimized using the open operating head with outlet-hole diameter in 30 mm. In the engineering, the outlet hole provides a flow channel for discharging residual gas before the injection of sodium coolant for the first time. (author)

[en] At present, the most surrounding rocks of sandstone-type uranium mines in China are mudstone, sandstone, pelitic siltstone, and so on. They show the characteristics of soft rock. Such uranium deposit is not fit for in-situ leaching. If the uranium ores are mined by conventional mining method, one of the problems to be solved is the support technique in the soft rock roadway. So, taking a uranium mine in Inner Mongolia as the research object, the support technique in the soft rock roadway of the sandstone-type uranium deposits is studied. Through on-site engineering geological investigation and laboratory test, the main reasons for roadway damage are analyzed. A technique of support in the soft rock roadway of sandstone-type uranium deposits is put forward by drawing on the expericnce of soft rock roadway support in coal mines. The roadway shape and support parameters are optimized by using a numerical simulation method. The results verified the feasibility of the supporting technique. (authors)

[en] In the past few decades, extensive application of azoxystrobin has led to great concern regarding its adverse effects on aquatic organisms. The objective of the present study was to evaluate the reproductive toxicity of azoxystrobin to zebrafish. After adult zebrafish of both sexes were exposed to 2, 20 and 200 μg/L azoxystrobin for 21 days, egg production, the fertilization rate, the gonadosomatic index (GSI) and hepatosomatic index (HSI), 17β-estradiol (E2), testosterone (T) and vitellogenin (Vtg) concentrations, and histological alterations in the gonads and livers were measured. Meanwhile, expression alterations of genes encoding gonadotropins and gonadotropin receptors (fshb, lhb, fshr and lhr), steroid hormone receptors (era, er2b and ar), steroidogenic enzymes (cyp11a, cyp11b, cyp17, cyp19a, cyp19b, hsd3b and hsd17b) in the hypothalamic-pituitary-gonad (HPG) axis and vitellogenin (vtg1 and vtg2) in the livers were also investigated. The results showed that reduced egg production and fertilization rates were observed at 200 μg/L azoxystrobin. In female zebrafish, reduced E2 and Vtg concentrations, decreased GSI, increased T concentrations, and histological alterations in the ovaries and livers were observed at 200 μg/L azoxystrobin, along with significant down-regulation of lhb, cyp19b, lhr, cyp19a, vtg1 and vtg2, and up-regulation of cyp17, hsd3b and hsd17b. In male zebrafish, increased E2 and Vtg concentrations, reduced T concentration and GSI, and histological alterations in the testes and livers were observed after exposure to 20 and 200 μg/L azoxystrobin, along with significant up-regulations of cyp19b, cyp11a, cyp17, cyp19a, hsd3b and hsd17b, vtg1 and vtg2. Moreover, cyp11a, hsd3b, cyp19a, vtg1 and vtg2 in male zebrafish were significantly up-regulated after treatment with 2 μg/L azoxystrobin. The results of the present study indicate that azoxystrobin led to reproductive toxicity in zebrafish and male zebrafish were more sensitive to azoxystrobin than female zebrafish. - Highlights: • Azoxystrobin reduced egg production and the fertilization rate of adult zebrafish. • The sex steroid hormones and Vtg concentrations were altered by azoxystrobin. • Gonadal and hepatic pathology in zebrafish was induced by azoxystrobin. • Azoxystrobin induced expression alteration of genes in the HPG axis and livers. • Male zebrafish were more sensitive to azoxystrobin than female zebrafish. - Azoxystrobin induced adverse effects on zebrafish reproduction and male zebrafish were more sensitive to azoxystrobin than female zebrafish.

[en] We have developed a micro-porous gelling polymer layer which is formed on both the sides of support polyolefin separator with wet or dry processing technique. Morphologies of gel-coated layer are dependent on the compositions and process conditions, such as solvent/non-solvent combination and stretching ratios. The micro-porous gelling layer is used for the assembly of the lithium ion polymer battery of LG Chemical Ltd. The structure of battery is given elsewhere and the battery has excellent discharge performance with 94% of 2C discharge performance at room temperature