•On the surface of the low-activation ferritic-martensitic steel EK-181 after holding at 600 °C for 3000 h in a static lead melt two-layer oxide scale with a thickness of 5 to 45 µm is formed.•The ...scale is mainly represented by particles of iron oxides Fe3O4 and Fe2O3, and to a lesser extent by chromium oxides – Cr2O3.•The oxide films protect the ferritic-martensitic steel from the aggressive action of the liquid coolant.•Microstructure of the bulk of the material retains its stability during long-term exposure in liquid lead.
The behavior of low-activation 12% chromium ferritic-martensitic steel EK-181 (RUSFER-EK181) is investigated during holding in an oxygen-containing lead melt at 600 °C for 3000 h. Following this exposure, a 5 to 45 µm bi-layer oxide scale is formed on steel surface. Its outer and inner layers represent oxide films mainly enriched with iron and chromium, respectively. The X-ray diffraction and electron microscopy analyses show that the oxide scale is primarily represented by particles of Fe3O4 and Fe2O3 iron oxides, and to a lesser extent by Cr2O3 chromium oxides. A chromium-depleted region of the matrix several micrometers thick is found under the scale layer. It is shown that the bulk microstructure of steel retains its stability during long-term exposure in liquid lead. No qualitative changes are observed after such exposure.
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Using a composite-face paradigm, we examined the holistic processing induced by Asian faces, Caucasian faces, and monkey faces with human Asian participants in two experiments. In Experiment 1, ...participants were asked to judge whether the upper halves of two faces successively presented were the same or different. A composite-face effect was found for Asian faces and Caucasian faces, but not for monkey faces. In Experiment 2, participants were asked to judge whether the lower halves of the two faces successively presented were the same or different. A composite-face effect was found for monkey faces as well as for Asian faces and Caucasian faces. Collectively, these results reveal that own-species (i.e., own-race and other-race) faces engage holistic processing in both upper and lower halves of the face, but other-species (i.e., monkey) faces engage holistic processing only when participants are asked to match the lower halves of the face. The findings are discussed in the context of a region-based holistic processing account for the species-specific effect in face recognition.
Stratospheric aerosols (SAs) are a variable component of the Earth's albedo that may be intentionally enhanced in the future to offset greenhouse gases (geoengineering). The role of ...tropospheric‐sourced sulfur dioxide (SO2) in maintaining background SAs has been debated for decades without in situ measurements of SO2 at the tropical tropopause to inform this issue. Here we clarify the role of SO2 in maintaining SAs by using new in situ SO2 measurements to evaluate climate models and satellite retrievals. We then use the observed tropical tropopause SO2 mixing ratios to estimate the global flux of SO2 across the tropical tropopause. These analyses show that the tropopause background SO2 is about 5 times smaller than reported by the average satellite observations that have been used recently to test atmospheric models. This shifts the view of SO2 as a dominant source of SAs to a near‐negligible one, possibly revealing a significant gap in the SA budget.
Key Points
First in situ measurements of SO2 in the tropical UT/LS
Typical SO2 at the tropical tropopause is near 5‐10 pptv
Flux of SO2 across the tropopause is a minor source of stratospheric aerosol
In this work we investigate the reflectance spectra of the GaAs/AlGaAs/AlAs-based coupled microcavities consisting of two cavity layers separated and surrounded by distributed Bragg reflectors ...(DBRs). The observed optical modes are described by the coupled harmonic oscillators model with parameters derived from the modelling of the layered structure by the transfer matrix method. The theory explains the observed anticrossing behaviour of optical modes with position on the sample, being able to reveal the cavities thickness gradients.
The genomic DNA profiles of prostate cancers with aggressive features were compared to the profiles of matched normal DNA to identify genes that are selectively amplified in the cancer cells. One of ...the identified genes, MCM7, which is a component of the DNA replication licensing complex, has been studied extensively both at the DNA and protein levels in human prostate tissues. Approximately half of the prostate cancer specimens studied showed MCM7 gene amplification, and 60% of the aggressive prostate cancer specimens had increased MCM7 protein expression. Amplification or overexpression of MCM7 was significantly associated with relapse, local invasion and a worse tumor grade. Constitutive expression of MCM7 in a human prostate cancer cell line, DU145, resulted in markedly increased DNA synthesis and cell proliferation compared to vector-only controls, and an increased cell invasion in vitro. Indeed, MCM7 overexpression produced primary tumors 12 times larger than vector-only controls and resulted in a rapid demise of mice bearing those tumors. These studies implicate MCM7, and the DNA replication licensing gene family, in prostate cancer progression, growth and invasion.
The conditions of the beginning of adhesion in the friction pair “polymer composite F4K20–alloyed steel” were studied. An expression for determination of the load corresponding to adhesion was ...obtained. Experimental study of wear resistance including the moment of the beginning of catastrophic wear of F4K20 in the friction pair with steel were carried out.
Using TrkA or TrkB receptor gene knockout HT-22 cells, the selectivity of the interaction of the low-molecular-weight dipeptide BDNF mimetic GSB-106 (hexamethylenediamide ...bis(N-monosuccinyl-L-seryl-L-lysine)) with TrkB receptors was shown.
On a basis of processing of data of measurements of the world-wide neutron monitor network database NMDB by a global survey method in real-time, the behavior of the first two angular moments of ...cosmic ray distribution function are investigated during the periods of geomagnetic storms that were observed in 2017. It is shown that abrupt increases of positive amplitudes of zonal components, which can be considered as predictors of geomagnetic field disturbances with a probability around 75%, precede geomagnetic storms with Dst <-50 nT. The predictor's lead time is from a few hours to 1.5 days. A monitoring of geomagnetic disturbances is carried out in real-time mode and results of the forecasting is presented in the Internet through the link http://www.ysn.ru/∼starodub/SpaceWeather/global_survey_real_time.html.
The equilibrium composition of the system (LiCl–KCl)
eut
+ 1 mol % UCl
3
during titration with lead chloride at temperatures of 773, 873, and 973 K is calculated by thermodynamic simulation methods. ...The calculations were performed taking into account the activity coefficients of lead and uranium chlorides in the molten LiCl–KCl eutectic. Activity coefficients γ(PbCl
2
) = 0.42, γ(UCl
3
) = 5.73 × 10
–3
, and γ(UCl
4
) = 7.54 × 10
–5
are used at 773 K. As the temperature increases, the activity coefficients increase. For example, at 973 K the activity coefficients are as follows: γ(PbCl
2
) = 0.49, γ(UCl
3
) = 0.020, and γ(UCl
4
) = 3.04 × 10
–4
. In the LiCl–KCl melt, lead chloride only partially oxidizes UCl
3
to UCl
4
, because the difference between the formal standard potentials
and
is only about 0.2 V. Therefore, PbCl
2
is a weak oxidizing agent in this case. The difference between the
and
potentials increases with the temperature. Therefore, the equilibrium fraction of UCl
4
increases with the temperature and excess PbCl
2
. For example, at 773 K and a threefold PbCl
2
excess over stoichiometry, the average uranium valence is
n
= 3.27. At 973 K and the same PbCl
2
excess, the average valence of uranium increases to
n
= 3.36. In addition, the reduction of UCl
4
to UCl
3
with metallic uranium in the molten LiCl–KCl eutectic is simulated taking into account the activity coefficients of the components. In the temperature range from 773 to 973 K, the reduction has no thermodynamic difficulties and proceeds completely. The HSC-9.9 software was used for the thermodynamic calculations.
Published data are examined, and the choice of possible imitators for studying the electrochemical partitioning of americium and curium in molten salts is substantiated. Since the direct study of ...americium and curium is difficult because of their high radioactivity, the corresponding lanthanides (europium and gadolinium) are proposed for the use as imitators. The structures of their external electron shells are very similar, and the oxidation levels are also similar. The electrochemical partitioning in molten salts is concluded to be most promising, since similar media make it possible to conduct the process at elevated temperatures and they are more resistant to radiation than aqueous and organic solvents. The calculation results show that AmCl
3
is easily reduced to AmCl
2
at elevated temperatures in chloride melts. The conventional standard potentials of Am
2+
/Am and Cm
3+
/Cm in the molten LiCl–KCl eutectic according to the data of independent authors are presented. In the melts based on the LiCl–KCl eutectic, the electrode potentials of americium and curium are found to nearly coincide; hence, the direct electrochemical partitioning of these elements is theoretically impossible. The electroreduction potentials of the Eu/Gd couple are additionally estimated more precisely. The data obtained show that the conventional standard potentials of Eu
2+
/Eu significantly differ from those of Gd
3+
/Gd, unlike the pair of Am
2+
/Am and Cm
3+
/Cm, because of which europium and gadolinium cannot serve as imitators for studying the partitioning of americium and curium. In addition, the Eu
2+
/Eu couple cannot be used in the LiCl–KCl melt, because the reduction potential of europium is more negative than the reduction potential of lithium. The conventional electroreduction potentials of Mg, Sc, Sr, Ba, Pr, and Nd in the LiCl–KCl melt at different temperatures are examined. The data obtained show that, among the chosen elements, the potentials of magnesium are closest to the potentials of americium and the scandium potentials are close to those of curium, which makes them more preferable for studying americium and curium partitioning in the LiCl–KCl melt.
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