Quartz is, in most cases, the major gangue mineral found in the manganese ore. Mn iron, dissolved from the surface of ore, will determine the interfacial properties of the particles and, thus, their ...flotation behavior. In this work, the effect of Mn
2+
on quartz flotation was investigated through flotation tests. It was found that quartz can be depressed with Mn
2+
and floated with dodecylamine in the pH region 7–8. In order to prove the validity of the findings, UV spectrophotometry, FTIR and SEM-EDS were carried out. UV spectrophotometry tests results show that Mn
2+
can competitive adsorb with RNH
3
+
in the surface of quartz at acidic and neutral pH values. The FTIR measurements and SEM-EDS analysis indicate that Mn
2+
forms precipitation and adsorbs on the negatively charged quartz surface, it induces quartz recovery dropping in alkaline pH. Furthermore, in the case of sodium hexametaphosphate (SH), sodium silicate or citric acid, the effects of Mn
2+
were also studied. This depression in the given Mn
2+
did not disappear. Citric acid is an appropriate modifier to separate quartz depressed by Mn
2+
from other ores at pH 7.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Room temperature simultaneous doping of reduced graphene oxide films with oxygen, nitrogen and chlorine was performed through anodic polarization in a neutral nitrogen-deaerated KCl electrolyte. The ...thermodynamic electrochemical windows of water, dissolved nitrogen and chlorine anions were analyzed on the basis of the Pourbaix diagram. Anode polarization demonstrated that the nitrogen, water and chlorine anions can be oxidized at an applied potential of 1.7V vs. NHE. The oxidative products, i.e. oxygen, nitrate anion and hypochlorous acid, can react with the reduced graphene oxide surface. X-ray photoelectron spectroscopy proved the chlorine–nitrogen co-doping of the treated film, along with an increase of oxygen groups. Surface structure evolution was also confirmed by Raman and Fourier-transform infrared spectroscopies. The anodic doping can be hindered by covering the reduced graphene oxide surface with sulfate anions or forming stable carbon–nitrogen bonds. Incorporation of oxygen, nitrogen and chlorine also helps to enhance the supercapacitance of the doped film.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Buffer analyses have shown that air pollution is associated with an increased incidence of asthma, but little is known about how air pollutants affect health outside a defined buffer. The aim of this ...study was to better understand how air pollutants affect asthma patient visits in a metropolitan area. The study used an integrated spatial and temporal approach that included the Kriging method and the Generalized Additive Model (GAM).
We analyzed daily outpatient and emergency visit data from the Taiwan Bureau of National Health Insurance and air pollution data from the Taiwan Environmental Protection Administration during 2000-2002. In general, children (aged 0-15 years) had the highest number of total asthma visits. Seasonal changes of PM10, NO2, O3 and SO2 were evident. However, SO2 showed a positive correlation with the dew point (r = 0.17, p < 0.01) and temperature (r = 0.22, p < 0.01). Among the four pollutants studied, the elevation of NO2 concentration had the highest impact on asthma outpatient visits on the day that a 10% increase of concentration caused the asthma outpatient visit rate to increase by 0.30% (95% CI: 0.16%~0.45%) in the four pollutant model. For emergency visits, the elevation of PM10 concentration, which occurred two days before the visits, had the most significant influence on this type of patient visit with an increase of 0.14% (95% CI: 0.01%~0.28%) in the four pollutants model. The impact on the emergency visit rate was non-significant two days following exposure to the other three air pollutants.
This preliminary study demonstrates the feasibility of an integrated spatial and temporal approach to assess the impact of air pollution on asthma patient visits. The results of this study provide a better understanding of the correlation of air pollution with asthma patient visits and demonstrate that NO2 and PM10 might have a positive impact on outpatient and emergency settings respectively. Future research is required to validate robust spatiotemporal patterns and trends.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To study the chemical constituents in fresh fleshyscaleaf of Lilium lancifolium.
The constituents were separated. by various kinds of chromatography and their structures were identified on the basis ...of spectral analysis.
Ten compounds were identified regaloside A (1), regaloside C (2), methyl-a-D-mannopyranosid (3), methyl-ca-D-glucopyranoside (4), (25R, 26R) -26-methoxyspirost-5-ene-3p-yl-O-ca-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (5), (25R)-spirost-5-ene-3beta-yl-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (6), (25R, 26R)-17alpha-hydroxy-26-methoxyspirost-5-ene-3beta-yl-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyra nosyl-(1-->6)-beta-D-glucopyranoside (7), daucosterol (8), adenoside (9), berberine (10).
All compounds except 1 and 3 were isolated from this species for the first time, and berberine was first reported in genus Lilium.
Reactions of Cu(II), Cd(II), and Ni(II) with a new tetradentate ligand N 1,N 3-bis(1-(1H-benzimidazol-2-yl)ethylidene)propane-1,3-diamine (H2bbepd) afforded four mononuclear pincer-like complexes ...of Cu(H2bbepd)(ClO4)·CH3OH·ClO4 (1), Cd(H2bbepd)(CH3OH)(ClO4)·CH3OH·ClO4 (2), Ni(H2bbepd)(H2O)2·2ClO4 (3), and Ni(H2bbepd)(NO3)2 (4), respectively. The labile small coordinated components (anions or solvent molecules) on the apical coordination site of metal ions in complexes 1–4 display three different modes, which can be substituted by 4,4′-bipyridine (bpy) to obtain four new multinuclear complexes of Cu2(H2bbepd)2(bpy)2·4ClO4 (5), Cd4(H2bbepd)4(bpy)3(ClO4)2·6ClO4·(bpy)·2CH3OH·6H2O (6), {Ni(H2bbepd)(bpy)·2ClO4·CH3OH} n (7), and {Ni (H2bbepd)(bpy)·2NO3·CH3OH·H2O} n (8), respectively. Complex 5 is a binuclear dumbbell-like molecule, complex 6 is a rare example of discrete linear tetranuclear molecule, while complexes 7 and 8 are one-dimensional chains formed by an alternate arrangement of bpy molecules and mononuclear subunits. The differences in complexes 5–8 are largely dependent on the structure of the mononuclear precusors of complexes 1–4. All eight complexes are assembled into higher dimensional supramolecular frameworks by diverse nonconvalent interactions including unusual anion···π interactions between perchlorate and five-membered benzimidazole rings.
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IJS, KILJ, NUK, PNG, UL, UM
Microorganisms with diverse metabolic functions inhabit petroleum reservoir systems utilizing multiple electron acceptors, but current understanding about the composition and diversity of functional ...microbial community in offshore oilfields is still scarce. In this study, the diversity, phylogenetic distribution and abundance of microbes involved in the sulfur (S) and nitrogen (N) metabolisms in production water of a high-temperature offshore oilfield were described selectively based on the functional gene analysis using polymerase chain reaction (PCR) technique. The detected sulfate-reducing prokaryotes (SRP) were affiliated with δ-Proteobacteria, Thermodesulfobacteria, Nitrospira, Firmicutes and Euryarchaeota, and the key and dominant SRP in the two samples included the genera Archaeoglobus, Thermodesulfobacterium, Thermodesulfovibrio, Thermodesulforhabdus and Desulfomicrobium. The sulfur-oxidizing prokaryotes (SOP) belonged to α-, β- and γ-Proteobacteria, mainly represented by Roseovarius, Rhizobium, Methylobacterium, Thiobacillus and Thauera genera. In addition, the nitrate-reducing and denitrifying communities were composed of α-, β- and γ-Proteobacteria, among which Bosea, Pseudomonas, Marinobacter, Diaphorobacter and Mesorhizobium showed a relatively high abundance. The quantitative PCR results revealed that functional gene abundances of N metabolism (the napA, nirS and nosZ genes) were mostly higher than those of S metabolism (the aprA, dsrA, dsrB and soxB genes), and functional gene abundances in sample X1 were mostly higher than those in sample X2. This work provides basic data for the understanding of diversity, composition and distribution of functional microorganisms in offshore petroleum reservoir ecosystems, and also mitigation of the reservoir souring and control.
•S- and N-metabolizing communities detected in high-temperature offshore oilfield.•A suite of functional marker genes were analyzed.•Abundance of N-transforming communities was higher than that of S.•Results useful for management of offshore oil-reservoir corrosion and souring.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Magnesium (Mg) batteries have attracted growing attention because of their low cost and high volumetric capacity. Mg/S batteries are of particular interest because of the high capacities of Mg and ...sulfur, which cooperatively enable high energy densities. However, the shuttling polysulfides during the S0/S2– conversion impair the cathode stability and corrode the Mg anode. This work reports the in situ sulfurization of carbon-confined cobalt in a mesoporous matrix (MesoCo@C) through sulfur melt impregnation and its effectiveness in uplifting the cathode stability and alleviating the Mg anode corrosion (i.e., formation of magnesium sulfides/sulfates). The CoS x species play important roles in binding with polysulfides and regulating the notorious polysulfide shuttle. Both the carbon matrix and the preserved cobalt are excellent electron conductors and allow fast charge transfer to the CoS x species, which become the active sites that facilitate the interaction with magnesium polysulfides and improve the cathode kinetics. These combined effects collectively give rise to the stable capacity of 280 mAh/g at 0.2 C (1 C = 1675 mA/g) for at least 400 cycles.
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IJS, KILJ, NUK, PNG, UL, UM
A core-shell hybrid material of amorphous hydrous RuO2-coated carbon nanotubes (CNT–RuO2) with a RuO2 loading as high as 82.4wt% was prepared by a solution method using RuCl3 and NaHCO3 aqueous ...solutions. The effect of preparation conditions, especially the dripping speed of the NaHCO3 solution, on the formation of the core-shell structure was investigated, and the corresponding mechanism was discussed. Supercapacitive properties of the CNT–RuO2 and amorphous hydrous RuO2 electrodes with a thickness of over 200μm were studied and the crucial factors to govern their rate capability were analyzed. For the thick CNT–RuO2 electrode, a comparison of its specific capacitance before and after subtracting the effect of the voltage drop of discharge curves caused by the inner resistance of the CNT–RuO2 symmetrical supercapacitor indicates that electronic conductivity is more important than proton diffusion in determining its rate capability.
The supercapacitive properties of a thick electrode of the CNT–RuO2 core-shell hybrid material with a RuO2 loading amount of 82.4wt% were investigated. By a comparison between the specific capacitance of the CNT–RuO2 electrode before and after subtracting the effect of the voltage drop of discharge curves caused by the inner resistance of the CNT–RuO2 symmetrical supercapacitor, the electronic conductivity is confirmed to be more important than the proton diffusion kinetic in determining its rate capability. Display omitted
•CNT–RuO2 with a RuO2 loading of 82.4wt% was prepared by a solution method.•The dripping speed of the NaHCO3 solution affects the formation of the CNT–RuO2.•The supercapacitive properties of thick CNT–RuO2 electrode (215μm) were studied.•The electronic conductivity of the CNT–RuO2 electrode governs its rate capability.•How electronic conductivity affects rate capability is analyzed by a new method.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The stellarator plasma device has been widely studied as one of the candidate solutions paralleling the ITER project, and its coupling with a fission blanket can bring benefits promoting the ...development of fusion technology with stable energy production simultaneously. However, the neutronics optimization design for the stellarator-type Fusion-Fission Hybrid Reactor (FFHR) is extremely complex since the helical structure with a large amount of spline curved surfaces cannot be exactly described in most of the Monte Carlo simulation processes, and the preliminary design stage has also been a time-consuming and error-prone task with the requirements frequently changing. In this context, the mesh-oriented optimized method has been considered for the parametric modeling analysis in order to get the ideal structure without redundant topologic information, and the corresponding conversion process from computer-aided design (CAD) to Monte Carlo simulation has been fulfilled by the CAD-PSFO code. Moreover, the liquid type of thorium-uranium fuels has been selected as the solutes dissolve in the molten salt blanket with its multilayer structure, where the burnup feature and neutronics properties have been analyzed and explained with the help of the OMCB code. The stellarator-type FFHR has been designed as a compact multifunctional device that can incinerate plutonium and transmute the minor actinide isotopes with tritium self-sufficiency and the high-energy multiplication factor.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
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