Electrochemical corrosion performance of Cr and Al alloy steels using a J55 carbon steel as base alloy

Cr- and Al-modified alloy steels using J55 carbon steel as base alloy were produced by remelting in a vacuum. Their corrosion resistance was estimated by open circuit potential, electrochemical polarisation measurements and immersion tests in a 3.5 wt.% NaCl solution. The modified alloy steels exhibit higher corrosion resistance with a more positive open circuit potential, lower corrosion current density and higher impedance than J55 steel. The immersion tests showed that the new alloy steels have lower corrosion rates and smaller pitting depth than J55 steel and a low-Cr steel.     

Modeling of the mixed potential in hydrogen peroxide-based fuel cells

A one-dimensional mathematical model is developed for the study of the mixed potential associated with the hydrogen peroxide oxidation reaction (HPOR) at the cathode of hydrogen peroxide-based fuel cells. The complicated physicochemical processes, including mass transport, charge transport, and three simultaneous electrochemical reactions (the hydrogen peroxide reduction, hydrogen peroxide oxidation, and oxygen reduction reactions) are considered. The model is experimentally validated and shows good agreement with the literature experimental data. The model is then applied to the study of the mixed potential by varying the current density. It is found that the largest potential loss due to the HPOR occurs under the open-circuit condition (OCC), and the potential loss decreases with the superficial current density. In addition, the numerical results suggest that under the OCC, an increase in the concentrations of hydrogen peroxide and H⁺ ions leads to a decrease in the potential loss, but an increase in the hydrogen peroxide decomposition rate and the oxygen evolution rate.     

群孔干扰抽水试验在哈头才当水源地的应用

哈头才当水源地是鄂尔多斯市康巴什新区新选的水源地.为了达到B级精度要求,并优化开采方案,在布置一般性抽水试验的同时,选择合适的地段进行群孔抽水试验,不仅可以了解干扰井间相互影响程度和含水层的富水性,还可以利用群孔试验资料建立数值模型,采用有限差分方法进行水文地质参数求解,所求参数和单孔抽水试验结果相比差异不大,且更加客观合理.在水源地场地条件允许的情况下,实施大型群孔抽水试验是完全必要的.     

Cancer Cell Response to Anthracyclines Effects: Mysteries of the Hidden Proteins Associated with These Drugs

A comprehensive proteome map of T-lymphoblastic leukemia cells and its alterations after daunorubicin, doxorubicin and mitoxantrone treatments was monitored and evaluated either by paired comparison with relevant untreated control and using multivariate classification of treated and untreated samples. With the main focus on early time intervals when the influence of apoptosis is minimized, we found significantly different levels of proteins, which corresponded to 1%–2% of the total amount of protein spots detected. According to Gene Ontology classification of biological processes, the highest representation of identified proteins for all three drugs belong to metabolic processes of proteins and nucleic acids and cellular processes, mainly cytoskeleton organisation and ubiquitin-proteasome pathway. Importantly, we observed significant proportion of changes in proteins involved in the generation of precursor metabolites and energy typical for daunorubicin, transport proteins participating in response to doxorubicin and a group of proteins of immune system characterising response to mitoxantrone. Both a paired comparison and the multivariate evaluation of quantitative data revealed daunorubicin as a distinct member of the group of anthracycline/anthracenedione drugs. A combination of identified drug specific protein changes, which may help to explain anti-cancer activity, together with the benefit of blocking activation of adaptive cancer pathways, presents important approaches to improving treatment outcomes in cancer.     

Diet supplementation with donkey milk upregulates liver mitochondrial uncoupling,reduces energy efficiency and improves antioxidant and antiinflammatory defences in rats

Dietary PUFA, mainly those of the n‐3 family, are known to play essential roles in the maintenance of energy balance and in the reduction of body fat deposition through the upregulation of mitochondrial uncoupling that is the main source of reactive oxygen species. We hypothesized that rat supplementation with raw donkey's milk (DM), characterized by low‐fat content and higher n3:n6 ratio, may affect energy balance, lipid metabolism, and prooxidant status as compared to animals treated with cow's milk. In the present study, the effects of drinking raw DM (for 4 weeks) on energy balance, lipid metabolism, antiinflammatory, and antioxidant/detoxifying defences was compared to that produced by rat intake of an iso‐energetic amount of raw cow's milk. The hypolipidemic effect produced by DM paralleled with the enhanced mitochondrial activity/proton leakage and with the increased activity or expression of mitochondrial markers namely, carnitine palmitoyl transferase and uncoupling protein 2. The association of decreased energy efficiency with reduced proinflammatory signs (TNF‐α and LPS levels) with the significant increase antioxidant (total thiols) and detoxifying enzyme activities (glutathione‐S‐transferase NADH quinone oxidoreductase) in DM‐treated animals, indicated that beneficial effects were attributable, at least in part, to the activation of nuclear factor 2 erythroid‐related factor 2 pathway.     

A theoretical study on the charge transport properties of DNA

The charge transport properties of DNA are studied by the first-principle simulation to discuss the possibility of applying DNA to molecular wire. Both the hopping model and band-like model are introduced. By using hopping model, the theoretical hole mobilities calculated by Marcus theory between the same bases in DNA are 5.6 × 10⁻³, 4.1 × 10⁻², 2.0 × 10⁻² and 1.2 × 10⁻⁴ cm²V⁻¹s⁻¹ for T-T, A-A, C-C and G-G; and the calculated electron mobilities are 5.3 × 10⁻⁸, 1.5 × 10⁻⁴, 8.1 × 10⁻⁷ and 7.5 × 10⁻¹⁰ cm²V⁻¹s⁻¹ for T-T, A-A, C-C and G-G, respectively. And the charge transport for both holes and electrons between different bases exhibits directivity. By using band-like model, we calculated the band width of DNA with double helix structure and bilinear structure to investigate which structure will facilitate to the charge transport. We found that the band width of DNA increased when DNA transforming from the double helix structure to the bilinear structure, which means DNA with the bilinear structure possesses better charge transport properties. This research sheds a light on the molecular design for the molecule serving as the molecular wire.     

Numerical simulation and verification of gas transport during an atomic layer deposition process

Atomic Layer Deposition (ALD) is a process used to deposit nanometer scale films for use in semiconductor electronics. The reactor consists of a warm wall horizontal flow tube, a substrate mounted on a disk downstream from the inlet, and cyclic flow between a reactant gas, a purging gas and a gas that preps the surface of the substrate. The objective is to achieve a uniform coating on the substrate layer by layer in minimal time. It is possible to use in situ monitoring of the gas phase and deposition to modify layer formation. Process improvement is currently accomplished experimentally by monitoring the precursor delivery and the growth of the film and adjusting the parameters: flow rates, temperature, pressure, concentrations, etc. Accurate simulation and optimization can decrease processing time and cost and increase control during product development. In addition, increased accuracy of gas transport simulation can be used to analyze reaction and diffusion rates, reaction mechanisms and other physical properties. In this paper we introduce the first comprehensive numerical solution of the Dusty-Gas Model including the complete binary diffusion term. We derive a concentration dependent Damkohler number relevant to the purge step of the process. The simulation matched the experimental data at a specific Damkohler number and further variation of the parameter confirmed existing experimentally observed phenomena.     

Process and terminations variations aware stability criteria for microwave amplifiers

Two novel process variations aware, necessary and sufficient conditions suitable for implementation in CAD optimizers are proposed to check amplifiers stability. Case studies are presented, showing that the new criteria allow robust amplifier design, under variation of active device immittance parameters in pre‐specified rectangular regions, due to manufacturing tolerances. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE 23: 619–626, 2013.     

Characterization of three- and four-point bending properties of porous metal fiber sintered sheet

A novel porous metal fiber sintered sheet (PMFSS) with high porosity was fabricated by the solid-state sintering method of copper fibers. In this study, both three- and four-point bending setup were established to characterize the bending properties of PMFSS. Similar three stages in the three- and four-point bending fracture process were observed for the PMFSS with 80% porosity sintered at 900 °C for 60 min. Comparing with the three-point bending, it is found that much smaller bending force was obtained in the four-point bending test under the same displacement conditions. Moreover, the porosity and sintering parameters were also varied to investigate the influence on the bending properties of PMFSS. Both three- and four-point bending strength were found to be decreased with increasing porosity ranging from 70% to 90%. Higher sintering temperature produced higher bending strength for the PMFSS sintered in the temperature range of 700–1000 °C. Besides, the extension of holding time also could slightly affect the bending strength.     

Effect of port configuration on discharge from a HICOM® mill

The discharge behaviour of different port configurations in a HICOM mill is investigated using DEM simulation. The charge in the mill is strongly sheared and circulates rapidly but has a free surface shape that is constant and which rotates with the mill rotation. The horizontal cross-sectional area of the charge decreases with increasing height. Particles within the mill discharge when the rotating charge flows over and is pushed towards the discharge ports. DEM enables the prediction of transient and steady state mass flow rates from each of the individual discharge ports. Twelve discharge ports at different locations in the mill are used here to explore the optimality of the various size and location options and to explore if there is any interaction in the discharge between adjacent ports. This provides information relevant to the operation of this type of mill, guidance for port selection and provides a general demonstration of how DEM can be used to predict transport and discharge behaviour of mills.