[en] Ferroelectric Ba(Sn_0.15Ti_0.85)O₃ (BTS) thin films were deposited on LaNiO₃-coated silicon substrates via a sol-gel process. Films showed a strong (1 0 0) preferred orientation depending upon annealing temperature and concentration of the precursor solution. The dependence of dielectric and ferroelectric properties on film orientation has been studied. The leakage current density of thin films at 100 kV/cm was 7 x 10^-7 A/cm² and 5 x 10^-5 A/cm² and their capacitor tunability was 54 and 25% at an applied field of 200 kV/cm (measurement frequency of 1 MHz) for the thin films deposited with 0.1 and 0.4 M spin-on solution, respectively. This work clearly reveals the highly promising potential of BTS compared with BST films for application in tunable microwave devices

[en] Irradiation can induce genomic instability and produce a series of delayed mutations. As a free-error repair mechanism of post-duplication, mismatch repair plays an essential role in the maintenance of genomic stability. Mismatch is proposed a kind of conservative repair mechanism. Not only can it be involved in the repair process directly by heterodimers, but it can affect the cell-cycle by cdc2 phosphatized path to supervise the cell-cycle indirectly. Therefore, discussing the relation of genomic instability and mismatch repair may represent one of aspects of radiation damage and repair mechanisms

[en] The high-temperature deformation behaviour and microstructure evolution of an extruded Al-Cu-Li alloy were investigated by compression tests conducted at various temperatures (613, 673 and 733 K) with various strain rates (0.001, 0.01, and 0.1 s"-"1). The results indicated that the deformation activation energy increased from 208.7 kJ/mol to 255.7 kJ/mol with an increase in strain from 0.1 to 0.7. The electron backscatter diffraction maps indicated that a dynamic recrystallisation occurred during the high-temperature deformation. Two types of recrystallisation mechanisms, grain boundary bulging and a grain boundary transformation from low misorientation to high misorientation, were considered as the mechanisms for controlling the formation of the recrystallised grains. A new dynamic recrystallisation model containing these two mechanisms was proposed to describe the microstructure evolution of the extruded Al-Cu-Li alloy. At the early stage of the deformation, the recrystallised grains were formed by grain boundary bulging along the original grain boundaries. With increasing strain, recrystallised grains were gradually generated in the deformed grains due to the transformation from low angle boundaries to high angle boundaries

[en] Highlights: • A small amount of MnO₂ doping the SBN-glass-ceramics makes BDS reach to 1470.6 kV/cm. • The theoretical energy storage density of the SBN-glass-ceramics with MnO₂ addition gets 9.2 J/cm³. • A small amount MnO₂ doping the BSN-glass-ceramics makes the leakage current densities decrease to 10⁻⁶ A/cm². • A small amount of MnO² doping the SBN-glass-ceramics can effectively decrease the dielectric loss of the materials. - Abstract: The effects of MnO₂ content on the structure and dielectric properties of the SBN-glass-ceramics were studied. The results show that a small amount of MnO₂ doping of the SBN-glass-ceramics can make their microstructure become denser and more uniform and MnO₂ doping of the SBN-glass-ceramics, as a grain growth inhibitor, has an evident effect on the reduction of grain sizes. The Mn ions exist in the form of Mn³⁺ and Mn⁴⁺ ions in the SBN-glass-ceramics, as confirmed by XPS measurements and Mn³⁺ and Mn⁴⁺ ions easily form charge defect complexes, which causes the leakage current densities of the SBN-glass-ceramics to obviously decrease. And a small amount of MnO₂ doping of the SBN-glass-ceramics can effectively decrease the dielectric loss of the materials. When 0.05 mol% MnO₂ is added to the SBN-glass-ceramics, the BDS is up to 1470.6 kV/cm and the theoretical energy storage density reaches the maximum value of 9.2 J/cm³.

[en] Genomic instability induced by radiation is characterized by the increased rate of acquisition of genetic alterations in the progenies of irradiated cell. These changes encompass a diverse set of biological end points, such as karyotypic abnormalities, gene mutation and amplification, and delayed reproductive cell death etc. Damages of some key genes play important roles in the initiation and transition of genomic instability. Epigenetic factors may influence the onset of genomic instability. Loss of stability of the genome is one of the important aspects of radiation carcinogenesis

[en] A new K_2O–SrO–Nb_2O_5–B_2O_3–Al_2O_3–SiO_2 (KSN-BAS) glass-ceramic system has been prepared by conventional controlled-crystallization method. The crystallization behavior and dielectric properties of the glass-ceramics were investigated. The X-ray diffraction analysis showed that the KSr_2Nb_5O_1_5 and SrNb_2O_6 phases with tungsten bronze structure were precipitated from the glass matrix, as the crystallization temperature increased, the AlNbO_4 phase was observed. The microstructure observed the sizes of grains became larger and presented the grain reunion severely. The dielectric constants of all the samples exhibited excellent stability from −90 °C to 120 °C and low dielectric losses less than 0.03. A maximum dielectric constant was obtained at annealing of 900 °C. The dielectric breakdown strength (BDS) reduced as the crystallization temperature increased. A maximum BDS can attain1213.76 kV/cm and a maximum energy storage density can reach up to 4.41 J/cm"3. - Highlights: • The energy storage density of original glass-ceramic can reach to 4.41 J/cm"3. • The single phase of high dielectric constant can be found in this glass-ceramic. • The material is regarded as a linear material without any ferroelectric behavior. • The heat treatment method is used to study the new glass-ceramic system. • The paper elaborated the effect of crystallization temperature on the properties

[en] The experiments were done using p⁺n junction irradiated with 12 MeV electron. Four electron traps were observed in Si layers: A-center E₁(E_c-0.19 eV), the divacancy E₂(E_c-0.24 eV), and E₄(E_c-0.44 eV), and E3 defect level (E_c-0.37 eV). Using DLTS method in conjuntion with the reverse recovery technique, annealing behavior of E₁, E₄ and E₃ traps have been studied. The annealing temperature of the E₃ defect is the highest (approx.= 520 deg C). We get an activation energy for thermal annealing of 1.71 eV with a frequency factor of ∼1.5 x 10⁹ s^-1. The E₃ and E₄ defect levels are the principal recombination center that controls lifetime of minorities following irradiation. As the E₂ and E₄ defect level annealout, however, defect level E₃ becomes the dominant recombination center

[en] RNA interference is an typical gene regulation pathway. The article focuses on the mechanism and the mediate role of siRNA. Being a potentially powerful tool to study specific gene function, the mechanism of cellular defense and the efficiency RNA surverillance, RNAi technology will be applied in radiobiology by provide effective tools for not only the research of radiosensitivity and radiation damage, but also radiotherapy. (authors)

[en] The experiments were done using a p⁺n junction irradiated with 12 MeV-electrons. Four electron traps were observed in Si layers: A-center E₁(E/sub c/-0.19 eV), the divacancy E₂ (E/sub c/-0.24 eV), and E₄ (E/sub c/ -0.44 eV), and E₃ defect level (E/sub c/ -0.37 eV). Using DLTS method in conjunction with the reverse recovery technique, annealing behaviors of E₁, E₄, and E₃ traps have been studied. The annealing temperature of the E₃ defect is the highest (≅520 ⁰C). We obtained an activation energy for thermal annealing of 1.71 eV with a frequency factor of --1.5 x 10⁹ s^-1. The E₃ and E₄ defect levels are the principal recombination centers that control the lifetime of the minority carrier following irradiation. As the E₂ and E₄ defect levels anneal out, the defect level E₃ becomes the dominant recombination center

[en] Ba(Zr_0.35Ti_0.65)O₃ (BZT) thin films were deposited via a sol-gel process on Pt-coated silicon substrates. The BZT films were in the perovskite phase and had polycrystalline structure. Temperature-dependent dielectric measurements revealed that the thin films have relaxor behavior and diffuse phase transition characteristics. The tunability K of the dielectric constant (at 600 kV/cm) is about 40% in the temperature range of 179-293 K. The improved temperature stability from this BZT thin film is beneficial to applications requiring a wide range of operating temperatures, thereby eliminating the need for environmental controls. Although the K value is not extraordinarily large compared to (Ba,Sr)TiO₃, the low dielectric constant of BZT is attractive for microwave frequency applications. This provides an additional possibility in balancing K and dielectric constant through materials engineering for optimum device performance