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This work explores mechanical properties, structural evolution, and mechanism of creep-life enhancement for widely used P9 heat-resistant steel. The 17-year-on-site used P9 alloy exhibit a higher tensile strength and a smaller elongation than the new P9 alloy from room temperature to 700 °C. The P9 alloy also displays a typical ductile feature with a significantly necking profile. The P9 alloy shows phase transformation sequences of α-Fe (bcc) →Ac1∼858 °Cα + γ -Fe (bcc + fcc) →Ac3∼894 °Cγ-Fe (fcc) upon heating and γ-Fe (fcc) →Ms∼352 °Cmartensite (bct) →Mf∼300 °Cmartensite (bct) upon cooling. The new P9-alloy tube mainly contains ∼73.5% ferrite phase (α-Fe) and ∼26.5% carbide M3C. However, the used P9-alloy tube shows four crystalline phases including ∼45.9% ferrite, ∼14.5% martensite, ∼37.5% cementite (M3C) and ∼2.7% carbide M23C6. The creep test indicates that the used P9-alloy tube has a longer creep-life (or better anti-creep ability) than the new tube. Activation energies of atomic diffusion for the new and used tubes are respectively 252.45 and 345.87 kJ/mol, indicating a decreased diffusion capability in the used tube. This work suggests that martensite laths, lath boundaries, and precipitates (such as carbides) play important roles to inhibit creep-deformation in the P9-alloy steel.

Growth inhibition and apoptotic/necrotic phenotype was observed in nanogold particle (AuNP)-treated human chronic myelogenous leukemia cells. To elucidate the underlying cellular mechanisms, proteomic techniques including two-dimensional electrophoresis/mass spectrometry and protein microarrays were utilized to study the differentially expressed proteome and phosphoproteome, respectively. Systems biology analysis of the proteomic data revealed that unfolded protein-associated endoplasmic reticulum (ER) stress response was the predominant event. Concomitant with transcriptomic analysis using mRNA expression, microarrays show ER stress response in the AuNP-treated cells. The ER stress protein markers’ expression assay unveiled AuNPs as an efficient cellular ER stress elicitor. Upon ER stress, cellular responses, including reactive oxygen species increase, mitochondrial cytochrome crelease, and mitochondria damage, chronologically occurred in the AuNP-treated cells. Conclusively, this study demonstrates that AuNPs cause cell death through induction of unmanageable ER stress.

AbstractSuccessive phase transitions have been observed in relaxor ferroelectric single crystals (PbMg1/3Nb2/3)1−x(PbTiO3)x(PMN-xPT) for x=0.24. 0.31 and 0.33, by using dielectric measurements and polarization-electric field (P-E) hysteresis loops. Phase coexistence that is characterized by broad dielectric maximum and gradual-evolution of remanent polarization, has been observed in these crystals. The field-cooled-zero-field-heated dielectric permittivity shows that the dc bias field induces a long-range ferroelectric phase transition.

Polarization-electric field (P-E) hysteresis loops and domain structures have been measured as a function of temperature in relaxor-based ferroelectric single crystal (PbZn1/3Nb2/3O3)0.915(PbTiO3)0.085 (PZN-8.5%PT). In order of increasing temperature, PZN-8.5%PT undergoes successive phase transitions: rhombohedra1 phase (below ∼375 K) → coexistence of rhombohedral and tetragonal phases (between ∼375 and ∼390 K) → tetragonal phase (between ∼390 and ∼420 K) → coexistence of tetragonal and cubic phases (between ∼420 and ∼460 K) → cubic phase (above ∼460 K). Phase coexistence suggests an inhomogeneous distribution of Ti4+ concentration in the PZN-8.5%PT crystal.

Dielectric permittivity along the [111] direction has been measured as a function of temperature for a relaxor ferroelectric single crystal (PbMg1/3Nb2/3O3)0.67(PbTiO3)0.33 (PMN-33%PT). A sharp ferroelectric phase transition was observed near 425 K and 429 K for cooling and heating processes, respectively. As temperature decreases, a diffuse phase transition (which begins near 330 K upon cooling) was detected. In addition, the nature of the thermal hysteresis for the dielectric permittivity confirms that these transitions (near 330 and 425 K upon cooling) are diffuse first-order and first-order, respectively. The frequency-dependent dielectric data ε'111 (ƒ, T) prove the existence of an electric dipolar relaxation process between 350 and 400 K. The activation energy, the Vogel-Fulcher temperature and attempt frequency corresponding to this relaxation process are also calculated.

Dielectric measurements in the mixed ferroelectric (FE)-antiferroelectric (AFE) system Rb1-x(ND4)xD2AsO4 (DRADA-x) (for ammonium concentrations x=0.39, 0.55, and 0.69) are reported. The phase coexistence of paraelectric (PE) and antiferroelectric (AFE) phases is confirmed in both x=0.55 and 0.69 crystals. A phase coexistence of deuteron-glass (DG) and antiferroelectric orderings is evidenced by the weak frequency dispersions (which occur below ∼ 100 K) in both dielectric permittivities (εa and ε“a) for x=0.39 crystal. The temperature-dependent data ε”a(f, T) proves the existence of an electric dipolar relaxation process forming among the antiferroelectric domains below ∼100 K.

Temperature and frequency dependent dielectric measurements in the mixed ferroelectric (FE)-antiferroelectric (AFE) system Rb1-x(ND4)xD2AsO4 (DRADA-x) (for ammonium concentrations x = 0.39, 0.55 and 0.69) are reported for measured fields along the a axis. These measurements, together with our previous light scattering results, confirm the phase coexistence of paraelectric (PE) and antiferroelectric (AFE) phases in both x = 0.55 and 0.69 crystals. Phase coexistence of deuteron-glass (DG) and antiferroelectric orderings is evidenced by the weak frequency dispersions (which occur below ∼100K) in both dielectric permittivities (ε'a and ''a) for the x = 0.39 crystal. The temperature-dependent data ε'a (f, T) prove the existence of an electric dipolar relaxation process below ∼ 100 K. The activation energy and attempt frequency corresponding to this relaxation process are calculated.