Xi’an, as one of the serious air pollution cities in western of China, many researches about the ambient air have developed. Limited has about the indoor air quality. In this study, PM2.5 samples were collected from household, offices, and ambient air in one community during haze periods. The regular composition including organic carbon (OC), element carbon (EC), water soluble ions, element, and polycyclic aromatic hydrocarbons (PAHs) of PM2.5 were discussed here. During the sampling time, ambient PM2.5 was the highest dispersed, and then followed by the household and offices, and outdoor diffusion is one of the main sources for indoors. However, the cooking activities in household were also another source of PM2.5 for household, with almost all the ratios of Kitchen/Sitting room (K/S) for different fractions were higher than 1. Though it has different composition in different environments, like organic matter (OM) in indoors attributed more than in ambient air, OM and water soluble ions were main parts of PM2.5. NO3- was a bit higher than SO42-, which might because of the decrease of SO42- emission here. Meanwhile, the average ratio of NO3-/EC and SO42--/EC indicated secondary oxidations were the main reasons for SO42+ and NO3-. For the elements, S, K, Ca, Fe, and Cl were the abundant elements. As exceed the WHO guidelines limit and the cancer risks of As displayed possible health impact for people here. PAHs also showed high pollution levels, with an average of 166.6 ng/m3 in ambient air, and 108.0 ng/m3 in household. Coal combustion, biomass burning and vehicle emission were still the main sources. The ILCR for all age groups were higher than 1×10-6, displayed that possible risks of PAHs were existed here, and PAHs pollution in this community need to be concerned.
A FRET–ICT dual-quenching fluorescent probe with significant off–on response toward H2S is rationally designed and prepared for imaging of H2S in living cells.
Mg3Sb1.5Bi0.5-based Zintl compounds have attracted extensive attention as potential thermoelectric materials due to their earth-abundant elements. However, pure and intrinsic Mg3Sb1.5Bi0.5 manifests a poor thermoelectric performance because of its low electrical conductivity of about 3 × 102 S/m at room temperature. In this work, In and Se co-doping was carried out to optimize the thermoelectric performance of n-type Mg3Sb1.5Bi0.5-based material. The experimental results revealed that the carrier concentration and mobility of Mg3Sb1.5Bi0.5 significantly increased after In and Se co-doping, leading to an improvement of power factor. Simultaneously, lattice thermal conductivity was significantly reduced due to the large mass difference between In and Mg. A maximum zT of 1.64 at 723 K was obtained for the Mg3.17In0.03Sb1.5Bi0.49Se0.01 sample. And an average zT value of about 1.1 between 300 and 723 K was achieved, which insures its possible application at medium temperature range as a non-toxic and low-cost TE material.
The stator immersed oil cooling has emerged as a promising thermal management method for high power density electric machines applied in aerospace applications. However, due to the complex geometry of end-winding, the research on the convective heat transfer coefficient (CHTC) for the flooded stator is still at infancy. This article investigates the convective heat transfer characteristics on end-winding of stator immersed oil-cooled electrical machines by computational fluid dynamics (CFD) methods and experiments implemented on a motorette. The variation law of the CHTCs of end-winding with flow rate is thoroughly investigated. Subsequently, new dimensionless correlations are defined using Nusselt numbers as a function of Reynolds numbers, which are further applied into a detailed lumped-parameter thermal network (LPTN) for rapid evaluation of temperature distribution. Finally, the obtained simulation results are verified by local temperature measurements. The experimental results also show that the proposed stator immersed oil-cooled structure can withstand a current density of up to 30 A/mm2 with a corresponding continuous power density of 6.8 kW/kg.
Photosynthesis requires chloroplasts, in which most proteins are nucleus-encoded and produced via cytoplasmic translation. The translation initiation factor eIF5B gates the transition from initiation (I) to elongation (E), and the Kozak motif is associated with translation efficiency, but their relationship is previously unknown. Here, with ribosome profiling, we determined the genome-wide I-E transition efficiencies. We discovered that the most prevalent Kozak motif is associated with high I-E transition efficiency in Arabidopsis, rice, and wheat, thus implicating the potential of the Kozak motif in facilitating the I-E transition. Indeed, the effects of Kozak motifs in promoting translation depend on HOT3/eIF5B1 in Arabidopsis. HOT3 preferentially promotes the translation of photosynthesis-associated nuclear genes in a Kozak motif-dependent manner, which explains the chloroplast defects and reduced photosynthesis activity of hot3 mutants. Our study linked the Kozak motif to eIF5B-mediated I-E transition during translation and uncovered the function of HOT3 in the cytoplasmic translational control of chloroplast biogenesis and photosynthesis. Cytoplasmic mRNA translation contributes to the production of most chloroplast proteins. Here, the authors revealed that an interplay between Kozak motifs and HOT3/eIF5B1 controls the translation of nucleus-encoded chloroplast proteins.
Abstract Hydrogen sulfide (H 2 S) is an important signalling molecule with multiple biological functions. The reported H 2 S fluorescent probes are majorly based on redox or nucleophilic reactions. The combination usage of both redox and nucleophilic reactions could improve the probe’s selectivity, sensitivity and stability. Herein we report a new dual-reactable probe with yellow turn-on fluorescence for H 2 S detection. The sensing mechanism of the dual-reactable probe was based on thiolysis of NBD (7-nitro-1,2,3-benzoxadiazole) amine (a nucleophilic reaction) and reduction of azide to amine (a redox reaction). Compared with its corresponding single-reactable probes, the dual-reactable probe has higher selectivity and fluorescence turn-on fold with magnitude of multiplication from that of each single-reactable probe. The highly selective and sensitive properties enabled the dual-reactable probe as a useful tool for efficiently sensing H 2 S in aqueous buffer and in living cells.
This book analyzes the legal regime of the exploitation of the mineral resources in the Antarctic. Therefore, it elaborates on the development of the Antarctic Treaty and the Antarctic Treaty System (ATS). The author examines the history and influence of the Convention for the Regulation of Antarctic Mineral Resource Activities (CRAMRA), which purpose it is to prohibit unregulated mineral resource activities in Antarctica, and its provisions are extremely strict with the aim of environmental protection. Through analyzing and comparing the CRAMRA and the 1991 Environmental Protocol, the book concludes that it is not beyond credulity to imagine that a new round of discussion on Antarctic mineral exploration will be held in the near future.
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