[en] One of prospective ways for boosting efficiency of luminescent materials is their combination with noble metal nanoparticles. Collective, so-called plasmon, oscillations of surface electrons in a nanoparticle can resonantly interact with incident or fluorescent light and cause an increase in the light absorption cross section or radiative rate for an adjacent emitter. Plasmonic inorganic phosphors require gentle host crystallization at which added noble nanoparticles will not suffer from aggregation or oxidation. The prospective plasmonic Mg₂TiO₄:Mn⁴⁺ phosphor containing core@shell Ag@SiO₂ nanoparticles is prepared here by spare low-temperature annealing of a sol-gel host precursor. It is revealed that Mn⁴⁺ luminescence nonmonotonously depends on the size and concentration of 40 and 70 nm silver nanoparticles. It is demonstrated that luminescence of the Mg₂TiO₄:Mn⁴⁺ phosphor can be up to a 1.5 times increase when Mn⁴⁺ excitation is supported by localized surface plasmon resonance in Ag@SiO₂ nanoparticles. © 2019 American Chemical Society.

[en] Highlights: • A rapid scratch electrode system in high temperature water has been built. • Repassivation kinetics of Alloy 690 was studied in high temperature water. • The slope of log i(t) vs. 1/Q(t) shows stress corrosion cracking susceptibility. - Abstract: The scratch electrode system in high temperature high pressure (HTHP) water has been built. The design temperature and design pressure of this system are 350 °C and 20 MPa respectively, and the maximum scratch speed is 3.3 m/s. By using this scratch electrode system, the repassivation kinetics of Alloy 690 in high temperature pressurized water with different dissolved hydrogen (DH) at 300 °C is studied. The research results justify that the scratch electrode system is valid and the scratch technique in HTHP water is a new effective and reliable method to study the SCC susceptibility of nuclear materials

[en] The verification and improvement were made on setting ways of the threshold about criticality accident alarm system (CAAS) in national standard GB 15146.9-1994. Source term parameters of different nuclear critical safety accidents in 'minimum criticality accident of concern' and shielding properties of various shielding materials were studied. Determination methods of revised threshold and effective operation radius were obtained. The results show that different fission source terms and shielding materials exert great impact on threshold setting of CAAS and it is required to take the contribution of secondary photon into consideration in terms of shielding material research. The formula of threshold after revision provides reference for application of CAAS in real plants. (authors)

[en] Single-component white light phosphors with a broad and full color spectrum are urgently required to overcome residual problems with commercial phosphors. In this paper, we describe how Eu3+, as the dopant of Sr3ZnTa2O9 (SZT), plays an important role in structural modulation (including structural order-disorder and intrinsic oxygen defects), as demonstrated by electronic structural calculations and systematic experiments. Furthermore, D-5(0) F-7(2) emission of Eu3+ provides the red component of the emission spectrum and increases the color rendering index of SZT:Eu3+ phosphors. Consequently, the resulting phosphor SZT:10%Eu3+ shows significantly enhanced emission intensity, and its broadband emission covers the entire visible region from 400 nm to 720 nm. A fabricated LED device using a near-ultraviolet 370 nm chip coated with a single-component, the SZT:10%Eu3+ phosphor, shows warm white emission with a high color rendering index (R-a = 82).

[en] This paper presents a new secondary loop of nuclear power plant system, including the main components of turbine, condenser, feed pump, and heater, with RELAP5 code. The research of the single component model adaptive authentication analysis and the local computing ability of the code have been studied. The results show that the steady state calculation results of the RELAP5 code are basically consistent with the design value, and the dynamic calculations are also able to meet the calculation accuracy request of the main components in secondary loop. (authors)

[en] The ratio of bubble departure diameter in pool boiling and flow boiling was introduced to modify the suppression factor S in the present study, then the modified S was used to substitute the suppression factor which appears in Lee-Mudawwar subcooled boiling CHF model. In addition, the bubble behavior in vertical rectangular channel was also analyzed. Then a new subcooled boiling heat transfer model was established based on the foregoing study. And the main factors which influence the heat transfer coefficient were also analyzed. Furthermore, the dependability of the model was validated through the comparison between the experimental and calculated values. The results show that the present model can be used to predict the subcooled boiling heat transfer characteristic in vertical narrow rectangular channel. (authors)

[en] Background: Gamma ray from the decay of "1"6N in main coolant of PWR is one important factor for radiation protection. Purpose: This paper attempts to develop a "1"6N specific activity calculating method based on the core neutron flux rate distribution. Methods: Firstly, the activation yield and the decay balance theory of "1"6N in main coolant of PWR were analyzed. A "1"6N specific activity calculating model based on sum of fluid channels in core was founded. The model made use of velocity of flow and average neutron flux rate in the fluid channels as input data. The steady "1"6N specific activities in main coolant while the reactor running could be calculated using this model. Subsequently, the model was practiced using Qinshan-2 NPP data. The reactor core was modeling in MCNP accurately. Neutron flux rate distribution in the core was calculated via MCNP simulation. The neutron flux rate data was used as input parameter of the calculating model, and the integrative calculation of "1"6N specific activity in main coolant was completed. Results: Result of the calculation was A_o_u_t=3.34×10"6 Bq/cm"3. It well matched the referenced value of 3.28×10"6 Bq/cm"3. Conclusions: The method was useful to calculate the "1"6N specific activity. (authors)

[en] Graphical abstract: The submicron/nano-structured morphology induced by OVPOSS has a strong effect on ice attachment. The OVPOSS particles aggregated on the top surface could decrease the ice adhesion strength. - Highlights: • Fluorinated hybrid films were fabricated from PMHS–xFMA and OVPOSS. • The hybrid films presented icephobic surfaces in submicron/nano-structure. • PMHS–17FMA could enhance hydrophobicity rather than icephobic properties. • Proper OVPOSS content (10–15 wt%) favored reducing the ice adhesion strength. • Rougher surface morphology (R_q > 90 nm) was benefit for repelling water droplets. - Abstract: Fluorinated hybrid films composed of fluorinated polymethylsiloxane (PMHS–xFMA, x = 6, 13, 17) and octavinyl-polyhedral oligomeric silsesquioxanes (OVPOSS) were prepared for icephobic applications. PMHS–xFMA with diverse fluorinated side groups were synthesized via hydrosilylation of polymethylhydrosiloxane (PMHS) with fluorinated methacrylate (xFMA), i.e., hexafluorobutyl methacrylate (6FMA), tridecafluorooctyl methacrylate (13FMA) and heptadecafluorodecyl methacrylate (17FMA), respectively. Characterizations of atomic force microscope and scanning electron microscope indicated that surfaces of the hybrid films consisted of submicron/nano-scaled OVPOSS aggregates, and the root-mean-square roughness (S_q) could vary from 42.6 nm to 145.2 nm with various OVPOSS content (5–20 wt%). Wettability measurements of the prepared films demonstrated that the relatively longer fluorinated side groups in PMHS–17FMA were beneficial for decreasing surface energy and enhancing hydrophobic properties. However, the fluorinated hybrid films with PMHS–17FMA presented higher ice shear strengths due to the stronger interfacial interactions between the film surface and ice/water. The film prepared by PMHS–13FMA and 10 wt% of OVPOSS with proper roughness (90.2 nm) performed the lowest ice shear strength (188.2 ± 13.4 kPa) among all the samples. Dynamic water droplet impact measurement revealed that the rougher surface with the mass fraction of OVPOSS more than 10 wt% and S_q larger than 90 nm could repel water droplets. The submicron/nano-structured surface of PMHS–xFMA and OVPOSS was expected for anti-icing applications.

[en] Liaohe super-heavy crude oil was separated into its components, namely saturates, aromatics, resins, and asphaltenes (SARA), by the group separation method. Several solvents were used to extract different forms of metallic elements from crude oil. The metallic elements, such as calcium, nickel, iron and manganese, in crude oil, SARA and extract samples were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results demonstrate that the contents of calcium, nickel, iron, and manganese gradually increase in saturates, aromatics, resins, and asphaltenes, suggesting that the abundance of the four metallic elements in asphaltenes is much higher than that in the other groups. For example, the content of calcium in asphaltenes reaches a maximum of 7,920 μg/g. Among the SARA components of Liaohe super-heavy crude oil, resins account for more than 50 wt%, suggesting that the total amount of the four metallic elements are higher in the resin component than in other components. The four metallic elements mainly exist in the form of organic metallic compounds in crude oil. Further analysis shows that calcium and manganese elements exist mainly as metal salts of petroleum acids, and the majority of the iron and all the nickel exist mainly as metalloporphyrin and non-metalloporphyrin compounds.

[en] As a new emerging semiconductor with interlayer bandgap, lead selenide (PbSe) have broad prospects in the fields of electrocatalysis, photocatalysis, infrared optoelectronic devices, optoelectronics, and ultrafast photonics. Among them, ultrafast photonics is receiving a lot of attention due to its ultrashort pulse, strong peak power, narrow bandwidth, and high repetition frequency. Herein, the properties are systematically studied of PbSe through various characterization methods. The modulation depth of PbSe is up to 30%, and its saturation light intensity is 7.86 MW cm${}^{-<!--\; ???\; -->2}$. Using the evanescent field effect, nonlinear fiber-based photonics devices has been successfully prepared based on the PbSe nanosheet solution, which can increase the bearable pump power. The 36th picosecond harmonic mode-locked soliton molecule is generated in the erbium-doped fiber laser, which corresponds to a maximum repetition frequency of 222 MHz. The results show that the signal-to-noise ratio can reach up to 49.1 dB which is higher than most previous works by now. The results revealed the potential of PbSe as an excellent photonics material in applications such as nonlinear optics, ultrafast photonics equipment, photoconductive detectors, and light modulators. (© 2022 Wiley‐VCH GmbH)