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Coal holds dominant position in China’s primary energy mix, and roughly 45% of China’s coal consumption is used for power generation. In this paper, we study the prospective of coal used for power generation in China into 2030 by testing three interrelated factors, namely electricity demand, fuel mix and generation efficiency of coal power. We find that, under the ‘new economic normal’, electricity demand growth would slow down; under the effort of low-carbon transition, coal power is expected to reach the peak at around 970GW by 2020; and coal used for power generation will reach the peak at around 1280 million ton coal equivalent (Mtce) under the clean coal power plan declared by the Chinese government.
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A new synthetic route to water-soluble ultra-small CdSe quantum dots (QDs) is proposed based on using a mixed complex of Cd(II) with ammonia and mercaptoacetate (MA) anions as a stabilizer and Na3SeO3 as a stable and non-volatile selenium precursor that can be reduced in situ to Se2− by MA. The method is facile, reproducible and allows gram-scale production of CdSe QDs in the form of powders, uniform and smooth films and concentrated solutions with a CdSe content up to 20 m%.
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Zvejnieki, on Lake Burtnieks in northeastern Latvia, is the largest known prehistoric cemetery in the eastern Baltic; >300 inhumations, most dating to c.7000–3000cal BC, have been excavated. Archaeozoological and artefactual evidence from graves and nearby settlement layers show that throughout this period, the community depended on wild resources for subsistence, with a particular emphasis on fishing. Dietary stable isotopes (δ15N and δ13C) from human remains show significant dietary variation within the Zvejnieki population, in terms of access to and dependence on freshwater and marine species (Eriksson 2006); we provide new stable isotope data for another 13 individuals. Elsewhere, we have proposed a method to correct the calibrated radiocarbon (14C) dates of prehistoric burials in the Lake Burtnieks region for dietary freshwater and marine reservoir effects (FRE/MRE) (Meadows et al. 2015). Here, we use this method to correct the dates of 40 individuals (including 3 from the nearby 4th millennium shell-midden site, Riņņukalns) for whom we now have both 14C and stable isotope data, and test whether there is any evidence that human diets changed over time, rather than simply varying between contemporaneous individuals. Three interesting transitions can be discerned: a shift away from high-trophic-level foods in the earlier 6th millennium cal BC, a diversification of diets in the late 5th millennium, with both more terrestrial and more coastal foods consumed, and a narrowing of diets in the mid-4th millennium, to concentrate on freshwater resources.
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A one-pot Amberlite IRA-400 Cl resin catalyzed the in-situ generation of imines from various aldehydes and primary amines followed by reduction with sodium borohydride affording corresponding secondary amines. The secondary amines thus obtained were utilized for the IRA-400 Cl resin catalyzed multicomponent synthesis of 3-aminoalkylated indoles using a number of aldehydes and indole. Mild condition, easy work-up, and environmentally benign nature of the synthetic strategy make it both practical and attractive.
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Historically and ethnographically dogs have been an important resource for Arctic and subarctic societies — providing protection, fur and meat, as well as aiding hunting and transportation. The close relationship between dogs and humans has also been used by archaeologists to draw inferences about human society (particularly in terms of diet and subsistence) from various analyses of their remains. Here, we apply the complementary approaches of stable isotope and zooarchaeological analysis to dog remains from the permafrost-preserved, pre-contact Yup'ik village site of Nunalleq (c. CE 1300–1750), in coastal western Alaska, specifically to investigate dog-human dietary relationships and the role that dogs played in this community. Zooarchaeological data indicate an abundance of dogs at the site, with butchery marks suggesting that they were processed for meat. Stable isotope analysis of multiple tissues indicates dog diet was largely based on fish (particularly salmonids), with possible short-term increases in marine mammal consumption. Comparison with data from contemporaneous human hair from Nunalleq indicates a close similarity between human and dog diets, supporting the use of dogs as a proxy for human palaeodiet in societies at high-latitude societies consuming significant amounts of animal protein.
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Natural organic matter (NOM) has considerable influence on the aggregation and stability of titanium dioxide nanoparticles (TiO2 NPs). However, the effect of chemical properties of NOM on the interface interaction and the aggregation process is still not clear. In this study, we investigated the effects of two typical types of NOM (fulvic acid (FA) and humic acid (HA)) on its adsorption onto TiO2 nanoparticles and their aggregation behavior in aqueous phase. Nuclear Magnetic Resonance (NMR) was used to study their functional groups, indicating that HA has a stronger hydrophobicity than FA. The presence of HA or FA lowered the critical coagulation concentration (CCC) of TiO2 NPs, while FA showed a more significant effect. HA promotes the aggregation of TiO2 NPs when ionic strength (IS)>CCC, which was likely due to the bridging effect. Contact angle measurements indicate that HA has higher hydrophobic properties than FA, and it is easier to transfer from water to the surface of TiO2 NPs. Transmission Electron Microscopy (TEM) was applied to investigate the aggregate formation and colloid interface morphology of NOM-coated-TiO2 NPs and NOM entanglement. Different structures of HA and FA result in various behavior and their interface interaction mechanisms including IS-induced entanglement and NOM/IS bridging.
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A new series of azo reactive dyes containing free chlorine atoms have been synthesized. The synthetic methodology involves the diazotization of 4′4-diamino diphenylamine-2-sulfonic acid (2) followed by azo coupling with 1-amino-8-naphthol-3,6-disulfonic acid (3) in alkaline medium to yield intermediate dye (4). Condensation of the latter with 1,3,5-trichlorotriazine afforded the cyanurated dye (5). A number of novel bis aromatic diamines (1a–j) were separately synthesized as bridging groups and were coupled with cyanurated dye (5) at room temperature to provide the target dyes designated as S1–S10 containing triazine and linker in a single molecule. The structures of newly synthesized compounds were confirmed by analytical data and spectroscopic techniques. The synthesized dyes were applied on cotton fibers to assess their light fastness, wash fastness and rubbing fastness and were found to possess medium to high fastness values in different dyes.
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We here present a dry coating of electrode particle with a model material of sulfide solid electrolytes for all-solid-state secondary batteries. LiNi1/3Co1/3Mn1/3O2 (NCM) was used as a host particle. Sodium sulfate (Na2SO4) was selected as a model material of sulfide solid electrolytes and used as a guest particle. Three different processes, which were vibration mixing, mortar-and-pestle mixing, and dry impact-blending process known as “Hybridizer”, were used and compared to each other. FESEM and EDX images showed that the dry impact-blending process produced composite particles in which NCM was more fully covered with Na2SO4 than using the vibration mixing and mortar-and-pestle mixing. Cross sectional observations of composite particles showed that using the dry impact-blending process continuous layer of Na2SO4 were formed on NCM particle. In a compacted pellet prepared from the composite particles produced by the dry impact-blending process, following features were observed: better dispersion of NCM particles in Na2SO4 matrix without NCM agglomerates; less void space; and intimate NCM-Na2SO4 interfacial contacts. These features suggest that performance of all-solid-state batteries are likely to remarkably improve using the composite particles prepared from the dry coating process.
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Photodegradation of 1,2-dichlorobenzene over illuminated trimetallic oxide consisting of rutile TiO2 in major portion together with WO3 and SnO2 was studied with respect to the effect of physicochemical properties of the catalyst. The photocatalytic activity enhancement by the presence of surface defects due to calcination temperature was investigated with the information obtained from XRD, DRUV, PL, FESEM and XPS. Calcination of TiO2 at 950°C resulted in highest activity. Decrease in percentage of degradation of 1,2-dichlorobenzene was noted when it was immobilized on PVC film and chitosan beads. The effect of calcination temperature, catalyst loading and pH was investigated for slurry and after immobilization. Further optimization study was carried out with the aid of response surface methodology utilizing Box–Behnken design. High correlation was obtained for the experimental and the predicted value (R2=0.9992, Adj. R2=0.9982 and Pred. R2=0.9971). Optimization result showed that the maximum percentage of degradation was achieved at calcination temperature of 961.2°C, with catalyst loading of 0.22g and pH 7.2. The presence of two intermediates was identified during the reaction using GC–MS. On top of that the photocatalyst could also be reused for several times.
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Microbial contamination of fuels, associated with a wide variety of bacteria and fungi, leads to decreased product quality and can compromise equipment performance by biofouling and microbiologically influenced corrosion of pipelines and storage tanks. Detection and quantification of biomass are critical in monitoring fuel systems for an early detection of microbial outbreaks. The aims of this study are (i) to quantify bacterial and fungal contamination in samples from diesel storage tanks of petrol stations, using both culture dependent- and culture independent (qPCR) approaches, and (ii) to analyse the diversity of cultivable diesel-contaminating microorganisms with the purpose to create a strain collection for further use in biodeterioration experiments.
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