Effect of low concentration electrolytes on the formation and corrosion resistance of PEO coatings on AM50 magnesium alloy

In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were systematically studied.The results show that the coatings prepared from the phosphate electrolytes have a higher thickness and better corrosion resistance properties compared to the other electrolytes.The coatings prepared from low concentration phosphate-aluminate mixed electrolytes have slightly thinner thickness,a similar coating structure and an order of magnitude lower value of electrochemical impedance compared with phosphate electrolyte coatings.The Coatings prepared from low concentration aluminate electrolytes have the lowest thickness and the worst corrosion resistance properties which gets close to corrosion behavior of the bare AM50 under the same test conditions.Considering application,coatings prepared from single low concentration phosphate electrolytes and low concentration phosphate-aluminate electrolytes have greater potential than single low concentration aluminate coatings.However,reducing the electrolyte concentrations of coating forming ions too much has negative influence on the coating growth rate.

Insight into MgO promoter with low concentration for the carbon-deposition resistance of Ni-based catalysts in the CO_2 reforming of CH_4

The CO2reforming of CH4is studied over MgO‐promoted Ni catalysts,which were supported on alumina prepared from hydrotalcite.This presents an improved stability compared with non‐promoted catalysts.The introduction of the MgO promoter was achieved through the‘‘memory effect’’of the Ni‐Al hydrotalcite structure,and ICP‐MS confirmed that only0.42wt.%of Mg2+ions were added into the Ni‐Mg/Al catalyst.Although no differences in the Ni particle size and basicity strength were observed,the Ni‐Mg/Al catalyst showed a higher catalytic stability than the Ni/Al catalyst.A series of surface reaction experiments were used and showed that the addition of a MgO promoter with low concentration can promote CO2dissociation to form active surface oxygen arising from the formation of the Ni‐MgO interface sites.Therefore,the carbon‐resistance promotion by nature was suggested to contribute to an oxidative environment around Ni particles,which would increase the conversion of carbon residues from CH4cracking to yield CO on the Ni metal surface.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Diluted low concentration electrolyte for interphase stabilization of high-voltage LiNi_(0.5)Mn_(1.5)O_(4) cathode

The Co-free Li Ni_(0.5)Mn_(1.5)O_(4)(LNMO)is a promising cathode for lithium-ion batteries owing to its high operating voltage and low costs.However,the synthesis of LNMO is generally time and energy consuming,and its practical application is hindered by the lack of a compatible electrolyte.Herein,a spray pyrolysis-based energy-saving synthesis method as well as a diluted low concentration electrolyte(0.5 M LiPF_(6) in a mixture of fluoroethylene carbonate/dimethyl carbonate/1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(FEC:DMC:TTE,1:4:5 by volume))are proposed to address these challenges.Owing to the unique features of the precursor prepared by spray pyrolysis,well-crystallized LNMO single-crystal can be obtained within 1 h calcination at 900℃.Besides,the fluorinated interphases derived from the diluted low concentration electrolyte not only mitigate the Mn dissolution and Al corrosion at the cathode side,but also suppresses dendritic Li deposition at the anode side,thus enabling stable cycling of both LNMO and Li metal anode.Thus,30μm Li|LNMO(1.75 m A h cm^(-2))cells achieve a high capacity retention(90.9%)after 168 cycles in the diluted low concentration electrolyte.

Effects of Low Concentrations of Di-(2-ethylhexyl) and Mono-(2-ethylhexyl) Phthalate on Steroidogenesis Pathways and Apoptosis in the Murine Leydig Tumor Cell Line MLTC-1

The aim of this study was to evaluate the effects of low concentrations of DEHP and MEHP on steroidogenesis in a murine Leydig tumor cell line （MLTC-1） in vitro. The result of flow cytometry analysis revealed that the proportion of apoptotic cells was significantly increased after the exposure to DEHP. All three genes （P450scc, P450c17, and 38HSD） under study showed an increased expression following exposure to DEHP or MEHP, although some insignificant inhibitory effects appeared in the 10μmol/L treatment group as compared with the controls. It was also found that DEHP or MEHP stimulated INSL3 mRNA and protein especially in the 0.001 μmol/L treatment group. Testosterone secretions were stimulated after the exposure to DEHP or MEHP. Alterations of steroidogenic enzymes and INSL3 in MLTC-1 cells might be involved in the biphasic effects of DEHP/MEHP on androgen production.

Recent progress of green sorbents-based technologies for low concentration CO_(2) capture

The increased concentration of CO_(2) due to continuous breathing and no discharge of human beings in the manned closed space,like spacecraft and submarines,can be a threat to health and safety.Effective removal of low concentration CO_(2) from the manned closed space is essential to meet the requirements of long-term space or deep-sea exploration,which is an international frontier and trend.Ionic liquids(ILs),as a widespread and green solvent,already showed its excellent performance on CO_(2) capture and absorption,indicating its potential application in low concentration CO_(2) capture.In this review,we first summarized the current methods and strategies for direct capture from low concentration CO_(2) in both the atmosphere and manned closed spaces.Then,the multi-scale simulation methods of CO_(2) capture by ionic liquids are described in detail,including screening ionic liquids by COSMO-RS methods,capture mechanism by density functional theory and molecular dynamics simulation,and absorption process by computational fluid dynamics simulation.Lastly,some typical IL-based green technologies for low concentration CO_(2) capture,such as functionalized ILs,co-solvent systems with ILs,and supported materials based on ILs,are introduced,and analyzed the subtle possibility in manned closed spaces.Finally,we look forward to the technology and development of low concentration CO_(2) capture,which can meet the needs of human survival in closed space and proposed that supported materials with ionic liquids have great advantages and infinite possibilities in the vital area.

Effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization in high myopia mice

AIM:To evaluate effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization(CNV)in high myopia mice.METHODS:The C57BL/6J mice were deprived of the right eye for 4wk,and the high myopia was diagnosed by optometry,the diopter was less than-6.00 D,and CNV was induced by 532 nm laser.The changes of dopamine D1 receptor(DRD1),dopamine D2 receptor(DRD2),and vascular endothelial growth factor A(VEGFA)were detected by Western blot technology at 0.5,1,2h,and 7d after 0.01%,0.05%,and 0.1%atropine eye drops,respectively,the area of CNV was measured.RESULTS:Significant increases were observed on the expression of DRD2 in mouse high myopia model at 0.5,1,2h,7d with 0.05%and 0.1%atropine eye drops(P<0.05).Significant decreases were observed on the expression of DRD1 and VEGFA in mouse high myopia model at 0.5,1,2h,7d with 0.05%and 0.1%atropine eye drops(P<0.05).The area of CNV induced by laser in the drug-treated group was significantly smaller than that in the control group,and the higher the concentration,the more significant the inhibitory effect(P<0.05).CONCLUSION:The 0.01%,0.05%,0.1%atropine eye drops can decrease the level of VEGFA and inhibit high myopia CNV indirectly by up-regulating the level of DRD2 and down-regulating the level of DRD1,and the effect of 0.05%and 0.1%atropine eye drops is more significant.

Preliminary clinical application of an adaptive iterative statistical reconstruction algorithm inhead and neck computed tomography angiography with low tube voltage and a low concentration of contrast medium

Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography angiography （CTA）. Methods Forty patients （22 men and 18 women; average age 48.7 ± 14.25 years; average body mass index 23.9 ± 3.7 kg/m^2） undergoing CTA for suspected vascular diseases were randomly assigned into two groups. Group A （n = 20） was administered 370 mgl/mL contrast medium, and group B （n = 20） was administered 270 mgl/mL contrast medium. Both groups were administered at a rate of 4.8 mL/s and an injection volume of 0.8 mL/kg. Images of group A were obtained with 120 kVp and filtered back projection （FBP） reconstruction, whereas images of group B were obtained with 80 kVp and 80% adaptive iterative statistical reconstruction algorithm （ASiR）. The CT values and standard deviations of intracranial arteries and image noise on the corona radiata were measured to calculate the contrast-to-noise ratio （CNR） and signal-to-noise ratio （SNR）. The beam-hardening artifacts （BHAs） around the skull base were calculated. Two readers evaluated the image quality with volume rendered images using scores from 1 to 5. The values between the two groups were statistically compared. Results The mean CT value of the intracranial arteries in group B was significantly higher than that in group A （P 〈 0.001）. The CNR and SNR values in group B were also statistically higher than those in group A （P 〈 0.001）. Image noise and BHAs were not significantly different between the two groups. The image quality score of VR images of in group B was significantly higher than that in group A （P = 0.001）. However, the quality scores of axial enhancement images in group B became significantly smaller than those in group A （P〈 0.001）. The CT dose index volume and dose-length product were decreased by 63.8% and 64%, respectively, in group B （P 〈 0.001 for both）. Conclusion Visipaque combined with 80 kVp and 80% ASiR provided similar image quality in intracranial CTA with 64% radiation dose reduction compared with the use of lopamidol, 120 kVp, and FBP reconstruc-tion.

Polypyrrole Chitosan Cobalt Ferrite Nanoparticles Composite Layer for Measuring the Low Concentration of Fluorene Using Surface Plasmon Resonance

Fluorene is a polycyclic aromatic hydrocarbon, which is a hazardous toxic chemical in the environment. The measurement of low concentrations of fluorene is a subject of intense interest in chemistry and in the environment. Polypyrrole chitosan cobalt ferrite nanoparticles are prepared using the electrochemical method. The prepared layers are characterized using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy. The layers are used to detect fluorene using the surface plasmon resonance technique at room temperature. The composite layer is evaluated after detection of fluorene using atomic force microscopy. The fluorene is bound on the layer, and the shift of the resonance angle is about 0.0052°, corresponding to the limitation of 0.01 ppm.

La-doped Pt/TiO_2 as an efficient catalyst for room temperature oxidation of low concentration HCHO

Catalytic oxidation of formaldehyde (HCHO) is the most efficient way to purify indoor air of HCHO pollutant. This work investigated rare earth La‐doped Pt/TiO2 for low concentration HCHO oxidation at room temperature. La‐doped Pt/TiO2 had a dramatically promoted catalytic performance for HCHO oxidation. The reasons for the La promotion effect were investigated by N2 adsorption, X‐raydiffraction, CO chemisorption, X‐ray photoelectron spectroscopy, transmission electron microscopy(TEM) and high‐angle annular dark field scanning TEM. The Pt nanoparticle size was reduced to 1.7nm from 2.2 nm after modification by La, which led to higher Pt dispersion, more exposed activesites and enhanced metal‐support interaction. Thus a superior activity for indoor low concentrationHCHO oxidation was obtained. Moreover, the La‐doped TiO2 can be wash‐coated on a cordieritemonolith so that very low amounts of Pt (0.01 wt%) can be used. The catalyst was evaluated in asimulated indoor HCHO elimination environment and displayed high purifying efficiency and stability.It can be potentially used as a commercial catalyst for indoor HCHO elimination.

Constructing built-in electric field via CuO/NiO heterojunction for electrocatalytic reduction of nitrate at low concentrations to ammonia

Electrocatalytic reduction of nitrate(NO_(3)^(-))at low concentrations to ammonia(NH_(4)^(+))still faces chal lenges of low NO_(3)^(-)conversion and NH_(4)^(+)selectivity due to the sluggish mass transfer and insufficien atomic hydrogen(H^(*))supply.Herein,we propose CuO/NiO heterojunction with the assistance of a built-in electric field to enhance mass transfer and H^(*)provision.The built-in electric field in Cu O/Ni O is success fully formed as demonstrated by X-ray photoelectron spectroscopy and ultraviolet photoemission spec troscopy.The results reveal that Cu O/Ni O achieves high NO_(3)^(-)reduction activity(100%)and NH_(4)^(+)selec tivity(100%)under low NO_(3)^(-)concentration conditions(100 mg/L NO_(3)^(-),ca.22.6 mg/L NO_(3)^(-)-N),which i superior to that of many recently reported electrocatalysts.Density functional theory calculations furthe clarify that the built-in electric field triggers the enhanced adsorption of reactants on CuO/NiO hetero junction interface and strong d-p orbital hybridization between reactants and CuO/NiO.Besides,the free energy diagram of hydrogen evolution reaction of CuO/NiO confirms the realization of enhanced H^(*)pro vision.Moreover,coupling experiments and consecutive cycle tests demonstrate the potential of CuO/NiO in practical applications.This work may open up a new path and guide the development of efficien electrocatalysts for electrocatalytic reduction of NO_(3)^(-)at low concentrations to NH_(4)^(+).

Efficient electrocatalytic reduction of nitrate to ammonia at low concentration by copper-cobalt oxide nanowires with shell-core structure

Electrocatalytic nitrate reduction to ammonia(NO3−RR)for removing nitrate from wastewater is a promising but challengeable technology that is increasingly studied.Herein,we developed an efficient CuO_(x)and CoCuO_(x)composed hybrid catalyst(CoCuO_(x)@CuO_(x)/copper foam(CF)),characteristic of distinctive shell-core nanowires grown on CF substrate with CuO_(x)core and CoCuO_(x)shell.The built-in electric field formed at the interface of the CoO/Cu_(2)O heterostructure promotes NO3−adsorption by modulating the charge distribution at the interface,which greatly improves the ammonia yield rate and Faradaic efficiency.At−0.2 V vs.reversible hydrogen electrode(RHE),CoCuO_(x)@CuO_(x)/CF achieves not only an excellent ammonia yield rate of up to 519.1μg·h^(−1)·cm^(−2)and Faradaic efficiency of 99.83%at 1 mM NO3−concentration,but also excellent mechanical stabilities.This study provides a novel pathway to design electrocatalyst for the removal of nitrate from dilute nitric acid solutions(≤2 mM).

Solvating power regulation enabled low concentration electrolyte for lithium batteries

Li^(+) solvation structures have a decisive influence on the electrode/electrolyte interfacial properties and battery performances.Reduced salt concentration may result in an organic rich solid electrolyte interface(SEI)and catastrophic cycle stability,which makes low concentration electrolytes(LCEs)rather challenging.Solvents with low solvating power bring in new chances to LCEs due to the weak salt-solvent interactions.Herein,an LCE with only 0.25 mol L^(-1) salt is prepared with fluoroethylene carbonate(FEC)and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether(D_(2)).Molecular dynamics simulations and experiments prove that the low solvating power solvent FEC not only renders reduced desolvation energy to Li^(+) and improves the battery kinetics,but also promotes the formation of a LiF-rich SEI that hinders the electrolyte consumption.Li||Cu cell using the LCE shows a high coulombic efficiency of 99.20%,and LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)||Li cell also exhibits satisfying capacity retention of 89.93%in 200 cycles,which demonstrates the great potential of solvating power regulation in LCEs development.

Progress and prospects of photocatalytic conversion of low-concentration NOx

NOx can cause severe environmental problems such as acid rain and photochemical smog,endangering human health and the living environment.Among them,NO pollution accounts for about 95%.NO can exist stably in the air for a long time when the concentration is lower than the ppm level.Therefore,the conversion of low concentration of NO has attracted more and more attention.However,traditional physical or chemical methods are difficult to deal with low concentration of NO,having high requirements on equipment and being not cost‐effective.Semiconductor photocatalytic technology can convert low concentration of NO into non‐toxic products and reduce its harm.This work briefly surveys the commonly used materials,modification methods,and mechanisms for semiconductor photocatalytic conversion of low concentration of NO.In addition,the challenges and prospects of ppb level of NO treatment are also discussed,aiming to promote the development of semiconductor photocatalytic conversion of NO.

High temperature H_(2)S selective oxidation on a copper-substituted hexaaluminate catalyst: A facile process for treating low concentration acid gas

H_(2)S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO_(2) and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCu_(x), x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H_(2)S selective oxidation reaction at high temperature conditions (300-550℃). The LaCu_(1) catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H_(2)S and SO_(2) in the tail gas.

Synergistic Treatment of Low-concentration Organic Waste Gas by Micro-nano Bubble Coordinated with Peroxymonosulfate

Continuous dynamic experiment was conducted for the treatment of low-concentration organic waste gas with xylene as a representative, using micro-nano bubble and peroxymonosulfate working in synergy. The degradation rule of xylene under different conditions such as the ORP value of the spray liquid, pH value of the spray liquid, liquid-gas ratio of the spray liquid, residence time of xylene, and initial concentration of xylene was investigated. The results showed that at a low concentration, the pH value of the spray liquid had little effect on the degradation rate of xylene. The degradation rate of xylene rose with the increase of the ORP value of the spray liquid, the liquid-gas ratio of the spray liquid, the residence time of xylene, and the initial concentration of xylene.

Myocardial perfusion imaging with a contrast agent at a low concentration in the diagnosis of myocardial infarction in the elderly

Objective To evaluate the clinical value of myocardial perfusion imaging with dual-source dual-energy CT and a contrast agent at a low concentration in the diagnosis of myocardial infarction in the elderly.Methods Onestop cardiac imaging with dual-source CT was conducted in 138 elderly patients diagnosed with myocardial infarction between October 2015 and May 2016.The

High aluminum concentration and initial establishment of Handroanthus impetiginosus : clues about an Al non-resistant species in Brazilian Cerrado

Cerrado soils are acidic and nutrient-poor,with high content of solubilized Al 3+.Plants growing in these conditions may display adaptations to cope with high aluminum concentrations especially during early developmental stages.We investigated leaf nutritional status,and photosynthetic and growth characteristics during the initial establishment of Handroanthus impetiginosus(Mart.Ex Dc.)Mattos,a secondary tree species distributed in the Brazilian Cerrado.Our goal was to understand leaf-level traits related to diff erent aluminum concentrations.H.impetiginosus plants were cultivated in four diff erent aluminum sulfate concentrations:0,1,2,and 4 mM Al,for 40 days.We performed analyses of growth,leaf gas exchange,chloroplast pigment content,and leaf mineral nutrients.We observed a linear increase of Al leaf content as a function of Al concentration in the nutrient solution.Plants grown in 1 mM Al showed a remarkable increase of K leaf content,net photosynthesis,stomatal conductance,and transpiration,while in 4 mM Al there were reductions of N,P,and K contents,gas exchange characteristics,and height.H.impetiginosus did not have mechanisms of avoidance,compartmentalization,or resistance to high Al concentrations.Indeed,this species showed a hormetic response,with low Al concentrations stimulating and high Al concentrations inhibiting plant responses.

Novel recovery of a low-concentration gold thiosulfate complex through electroreduction via a walnut shell charcoal electrode

Low-concentration Au(S_(2)O_(3))2^(3-)recovery is an urgent issue to facilitate the application of thiosulfate leaching instead of cyanide leaching in factories.Herein,this work presents a novel recovery of low-concentration Au(S_(2)O_(3))2^(3-) combining adsorption and electrodeposition(electroreduction)to realize high Au(S_(2)O_(3))2^(3-)recovery in the form of gold particles(Au^(0)).Walnut shells were used as the raw material for the successful preparation of charcoal with porous structure and rich oxygen-containing functional groups.Walnut shell charcoal(WSC)as the electrode achieved efficient recovery of low-concentration Au(S_(2)O_(3))2^(3-).The recovery under low-concentration conditions was higher than 90%,with the highest reduction of 46.97 mg·g^(-1).Applying a suitable low voltage(0.8 V)facilitated lowconcentration Au(S_(2)O_(3))2^(3-)recovery,which was immensely improved than that without voltage.Au(S_(2)O_(3))2^(3-)recovery performances under applied voltage via the WSC electrode were related to electrochemical abilities,including reaction intensity and charge transfer.More reactive sites containing suitable pores and oxygen functional groups were beneficial for the reduction reaction.This work offers a new way to recover low-concentration Au(S_(2)O_(3))2^(3-)via cheap charcoal electrodes from solutions for application in the cyanide-free leaching method in industry.

Geothermal,Oceanic,Wildfire,Meteorological and Anthropogenic Impacts on PM_(2.5) Concentrations in the Fairbanks Metropolitan Area

The impacts of low and high-frequency variability from teleconnections between large scale atmospheric processes and local weather as well as emissions changes on concentrations of particulate matter of 2.5 μm or less in diameter ([PM2.5]) were examined for the Fairbanks Metropolitan Area (FMA). October to March and May to August mean [PM2.5] were 1.8 and 3.1 μg&#183;m&#45;3 higher for positive than negative annual mean Pacific Decadal Oscillation. Annual mean [PM2.5] were 3.8 μg&#183;m&#45;3 lower for positive than negative Southern Oscillation Index. On 1999-2018 average, [PM2.5] decreased 2.9 μg&#183;m&#45;3&#183;decade&#45;1. On average over October to March, decadal and inter-annual variability caused higher or similar differences in mean observed [PM2.5] and its species than emission-control measures. The 2006 implementation of Tier 2 for new vehicles decreased observed sulfate concentrations the strongest (~4.95 μg&#183;m&#45;3&#183;decade&#45;1) of all occurred emissions changes. On average, observed [PM2.5] showed elevated values at all sites when wind blew from directions of hot springs. The same was found for the sulfate, ammonium and non-metal components of PM2.5. Observations showed that these geothermal waters contain sulfate, ammonia, boric acid and non-metals. Hot springs of such composition are known to emit hydrogen sulfide and ammonia that can serve as precursors for ammonium and sulfate aerosols.

Accuracy evaluation of Roche Accu-Chek Performa blood glucose meters at low glucose concentrations:A nine-year retrospective study

Objective:To evaluate the accuracy of Roche Accu-Chek Performa glucose meters at a low glucose concentration of<5.55 mmol/L(100 mg/dL)over a 9-year period.Methods:The accuracy of the Roche Accu-Chek Performa glucose meters at low glucose concentrations was evaluated using annual comparison data for 9 consecutive years from 2015 to 2023,according to the acceptability criteria specified in International Organization for Standardization(ISO)15197:2013.Blood samples with low glucose concentrations of<5.55 mmol/L were prepared by incubation and glycolysis.The glucose concentration was detected using Roche Accu-Chek Performa glucose meters and a biochemical analyzer in the central laboratory.Results:A total of 2978 pairs of comparison results from 211 glucose meters at a low glucose concentration of<5.55 mmol/L were retrospectively analyzed from 2015 to 2023.The clinical use duration spanned from 1 to 9 years and 40.76%(86 out of 211 glucose meters)had been used for more than 2 years.The correlation coefficient r between glucose meter measurements and laboratory reference values was 0.98(p<0.001).The mean according to Roche Accu-Chek Performa glucose meters was 0.05 mmol/L(0.9 mg/dL)higher than that of the biochemical analyzer(Z=-13.82,p<0.0001).The results showed that 100.00%(211 out of 211)of the Roche Accu-Chek Performa glucose meters met the acceptability criteria specified in ISO 15197:2013.At a low glucose concentration of<5.55 mmol/L,99.90%(2975 out of 2978)of the comparative data pairs in the error distribution fell within the range of±0.83 mmol/L(15 mg/dL).Parkes consensus error grid analysis showed that 100.00%(2978 out of 2978)of comparative data pairs fell within region A.Conclusions:This study demonstrated that Roche Accu-Chek Performa glucose meters successfully met the accuracy standards of ISO 15197:2013 for measuring blood glucose within the hypoglycemic range.Greater attention should be given to the performance of blood glucose monitoring systems in the low glycemic range,especially for patients with diabetes who are prone to hypoglycemia and require precise measurements.