[en] In this research, acoustic emission (AE) characteristics of three-point-bending concrete beams were investigated during the entire loading period. It was found that the relative notch depth significantly influenced AE characteristics. The occurrence of AE events decreased greatly with an increase of the relative notch depth. The influences of different fibers in concrete on AE characteristics were investigated as well. The experimental results indicated that the Weibull function can be used to describe quantitatively the influences of the relative notch depth and fibers on AE characteristics, fracture characteristics, and brittleness of concrete. The two parameters, θ and m, of the Weibull function depended on the geometry of the concrete specimens and the brittleness of concrete, respectively

[en] The key steps about nuclear power plant PSA-based seismic margin assessment are discussed in this paper. The analysis points include selection of seismic margin earth level, civil structures screening criteria, attentions about plant walkdown, HCLPF definition and the basic principles about CDFM compute the seismic margin capacity of structures. The methods and principles about HCLPF calculation are demonstrated by the nuclear power plant shear concrete walls. The study conclusion and experience can provide reference for the nuclear power plant seismic margin assessment and determine the nuclear power plant seismic margin capacity. (authors)

[en] Mixing between the 2³S₁ and 1³D₁ D_s is studied within the ³P₀ model. If mixing between these two 1^- states exists, D_s1^* (2700)± and D_sJ^* (2860)± could be interpreted as the two orthogonal mixed states with mixing angle θ≈-80° in the case of a special β for each meson. However, in the case of a universal β for all mesons, D_s1^* (2700)± could be interpreted as the mixed state of 2³S₁ and 1³D₁ with mixing angle 12° < θ < 21° but D_s^*J (2860)^± seems difficult to interpret as the orthogonal partner of D_s1^* (2700)^±. (authors)

[en] The concentrations of the serum free T₃(FT₃), free T₄(FT₄), total triodothyronine (TT₃), total thyroxine (TT₄) and thyrotropin (TSH) are determined for 355 cases of normal persons, pregnant women and various thyropathetic patients. The normal values of FT₃ and FT₄ are 2.0-8.5 pmol/l, and 9.5-26.5 pmol/l, respectively. Neither FT₃ nor FT₄ is affected by the thyroxine combined with globulin (TBG), which is of unique diagnostic value for those with variable TBG (such as pregnant women hyperthyroidism, hypothyroidism, etc.), FT₃ and FT₄ are the most sensitive indices for diagnosis of hyperthyroidism, and hypothyroidism, respectively. In addition, FT₃ and FT₄ can greatly contribute to the observation of curative effectiveness under treatment

[en] We revisit the harmonic approximation (HA) for a large Josephson junction interacting with some charge qubits through the variational approach for the quantum dynamics of the junction-qubit coupling system. By making use of numerical calculation and analytical treatment, the conditions under which HA works well can be precisely presented to control the parameters implementing the two-qubit quantum logical gate through the couplings to the large junction with harmonic oscillator Hamiltonian.

[en] Distribution of equivalent stress and equivalent strain was analyzed in the ECAP process based on material flow laws. Simulation results showed that severe plastic deformation occurred at the corner of the cavity, indicating a stress concentration at the equal channel angle. Distribution of stress and strain at the same section was not uniform. Equivalent stresses on the surface at the inside corner of the part were larger. Experimental results showed that forming speed and lubrication conditions had a great influence on quality of parts. The parts were in good condition with no wrinkle and rupture after ten ECAP passes. EBSD analyses showed that the original coarse grains were refined and uniformly distributed, and the average grain size of the cross section was about 620 nm after ten ECAP passes. With increasing the number of ECAP passes, the proportion of small angle grain boundaries decreased gradually and the ratio of large angle grain boundaries increased. Tensile strength and hardness increased sharply, while the elongation decreased sharply after the first ECAP pass. With succeeding the ECAP passes, the tensile strength, hardness and the elongation all increased slowly.

[en] Highlights: • The removal of naphthalene follows first order kinetics in seawater. • Irradiance and temperature are the most influential factors. • An increase in irradiance can linearly promote photodegradation. • High salinity suppresses the photodegradation of naphthalene. - Abstract: A large amount of oil pollution at sea is produced by the operational discharge of oily wastewater. The removal of polycyclic aromatic hydrocarbons (PAHs) from such sources using UV irradiation has become attractive, yet the photolysis mechanism in seawater has remained unclear. This study examines the photodegradation kinetics of naphthalene in natural seawater through a full factorial design of experiments (DOE). The effects of fluence rate, salinity, temperature and initial concentration are investigated. Results show that fluence rate, temperature and the interaction between temperature and initial concentration are the most influential factors. An increase in fluence rate can linearly promote the photodegradation process. Salinity increasingly impedes the removal of naphthalene because of the existence of free-radical scavengers and photon competitors. The results will help understand the photolysis mechanism of PAHs and develop more effective methods for treating oily seawater generated from offshore industries

[en] Highlights: • Flow instability has been studied under static condition and marine motion conditions. • Flow oscillation under motion conditions is the superposition of two flow oscillation. • Effect of marine motion conditions on flow oscillation period is small. • Effect of marine motion conditions on flow instability boundary heat flux is small. • An empirical correlation of flow instability boundary was developed based on the results. - Abstract: An experimental investigation was performed on two-phase flow instability with twin parallel rectangular channels under static condition and marine motion conditions. Marine motion conditions include inclination, fluctuation and rolling. The maximum inclination angle is 45°, maximum amplitude and acceleration of fluctuation are 0.8 m and 1.9 m²/s, respectively; maximum amplitude and angular acceleration of rolling are 30° and 0.5 rad/s², respectively. Test thermal parameters are 3–8 MPa for pressure, 300–700 kg/m²s for mass velocity, and 15–90 °C for inlet subcooling in this experiment. Comparisons have been made on four aspects: (1) general observation of flow oscillation; (2) period of flow oscillation; (3) flow instability boundary heat flux; (4) flow instability zone under static condition and motion conditions. Contrary to what is observed under static condition, the flow oscillation under motion conditions is actually the superposition of thermal-induced oscillation and motion-induced oscillation. But further comparison indicates that the influence of marine motion conditions on flow stability is very limited. In general, the period of oscillation, flow instability boundary heat flux and distribution of instability zone are much more affected by thermal parameters than the motion conditions and the point to point comparison shows that the differences of boundary heat flux brought by motion is no more than ±5%. Finally, an empirical formula considering a pressure correction is correlated based on experimental data, which is applicable for the prediction of the instability boundary under both static and motion conditions

[en] Nadong skarn type uranium mineralization is located in the polymetal metallogenic belt of Qimantage. Based on microscopic examination and EPMA analysis, it was found that uranium mineralization was hosted in rocks composed by uraninite magnetite galena pyrite. The principal gangue minerals are mainly plagioclase, quartz, biotite, calcite and so on. The main uranium mineral is uraninite, the rest of uranium to be found occurs through isomorphism or adsorption in changbaiite, monazite, huttonite, and thorianite. The uraninite have two kinds of existence form, granular and fissure. The mineralization is related to skarmization by the characteristics of uranium and iron symbiosis. Uranium mineralization time between quartz sulfide stage and carbonate stage of iron metallogenic period. (authors)

[en] We derive a local curvature estimate for four-dimensional stationary solutions to the Einstein equations coupled with electro-magnetic fields or scalar fields. In particular, it implies that any such stationary geodesically complete solution with vanishing Poynting vector and proper coupling constants is flat. We also generalize the results in static case to higher dimensions.