Search

The emergence of Li‐ion batteries provides a new path and scheme for carbon neutrality and carbon peak. The performance of lithium‐ion batteries is mainly determined by the electrode material. Among them, transition metal compounds have been widely studied in the anode and cathode materials of lithium‐ion batteries. Here, pure rare earth metal fluoride YF3 was synthesized by solvothermal method and subsequent calcination. The specific capacity of YF3 as a Li‐ion battery anode can increase from 29.3 mAh g−1 to 148.5 mAh g−1 after 1000 cycles at 0.1 A g−1, with a growth rate of up to 407 %. XPS and XRD tests confirmed that the lithium storage process was a typical conversion reaction. The successful application of YF3 in Li‐ion batteries provides a wider range for the selection of Li‐ion electrode materials and also provides a new idea for the exploration of new materials for lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

TheFossorochromis rostratusis a species of cichlid endemic to Lake Malawi in East Africa. In this study, we first reported the complete mitochondrial genome ofF. rostratus. The whole mitochondrial genome is 16 581 bp in length, which contains 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. The GC content of this mitochondrial genome is 45.96% (27.47% A, 26.57%T, 30.12% C, and 15.84% G), similar toAstatotilapia calliptera(the GC content of 45.90%). We constructed a phylogenetic tree on the complete mitochondrial genomes of these two species and other 10 closely related species to show their phylogenic relationship. The complete mitochondrial genome ofF. rostratusand its phylogenic relationship with other related species would facilitate our understanding of the evolution of Cichlidae mitochondrial genome. [ABSTRACT FROM AUTHOR]

Summary: The D/H and 18O/16O ratios in atmospheric water vapor provide rich information on the hydrological cycle and gaseous exchange processes between the terrestrial vegetation and the atmosphere. In this paper, we have demonstrated the feasibility to simultaneously measure both D/H and 18O/16O in atmospheric water vapor using a tunable diode laser absorption spectrometer. Our laboratory tests showed that the 1-h precision (one standard deviation) was 1.1‰ for D/H and 0.07‰ for 18O/16O at the dewpoint temperature of 15°C. The difference between the laser measurement and cold trap/mass spectrometer analysis was 1.2±6.0‰ (hourly mean±one standard deviation) for D/H and 1.1±1.3‰ for 18O/16O. Our atmospheric measurement captured the rapidly changing isotopic signals in both D/H and 18O/16O. The measured isotope ratios were highly correlated with the water vapor mixing ratio as expected and followed very closely the Global Meteoric Water Line except during two transitional periods when the deuterium excess of atmospheric vapor deviated from the standard value. In addition, we have refined a method to provide independent, timely performance test of the in situ system. [Copyright &y& Elsevier]

To investigate the effect of biomass burning in Changchun in autumn on the absorbance of water-soluble organic carbon (WSOC) on PM 2.5 , PM 2.5 samples were collected from October to November 2017. The light absorption characteristics of WSOC, carbonaceous components, and carbohydrate content in PM 2.5 were analyzed. The study showed that the average concentrations of WSOC, organic carbon (OC), and elemental carbon (EC) in PM 2.5 in Changchun were (10.12±3.47), (17.07±5.64), and (1.34±0.75) μg·m -3 , respectively; the average contribution rate of secondary organic carbon (SOC) to OC was 38.93%. The total sugar concentration in Changchun is (1049.39±958.85) ng·m -3 , of which the content of anhydroglucose (L-glucan, galactan, and mannan), as a biomass burning tracer in total sugar, was 91.69%. The results of sugar correlation analysis showed that biomass combustion was the main source of contribution to carbohydrates in the autumn of Changchun. The light absorption wavelength index of WSOC in autumn was 5.75±1.06, and the unit mass absorption efficiency was (1.23±0.28) m 2 ·g -1 , indicating that biomass combustion has an important influence on WSOC absorbance. The biomass combustion characteristic source parameter was used to quantify the contribution of biomass burning to WSOC concentration, which was found to be 58.82%, while the contribution to total WSOC light absorption was 40.92%.

Phytoplankton have a complex life-cycle. Resting cysts are formed like terrestrial plants. Cysts play important roles in resisting environmental pressure, surviving adverse environment, maintaining physiological homeostasis, and maintaining species reproduction. In some ecological events, cysts were served as "seed bank" for periodical algal blooming. However, compared with the mature cells, the ecophysiological research on cysts is relatively limited. To deepen our understanding on life-cycle and ecological roles of cysts, we reviewed the researches on cysts in the past two decades. Firstly, we outlined the types (resting cysts, zoocysts, mature cysts) and factors that affected the formation of cysts of typical dinoflagellates and diatoms. Secondly, we summarized the formation mechanism, physiological characteristics and germination factors of cysts. Finally, we discussed the significance of cysts in algal evolution and in ocean carbon cycle. This review, summarizing the adaptability and plasticity of cysts, would shed light on ecological mechanism of algae survival strategy.

Northeastern China experiences severe atmospheric pollution, with an increasing occurrence of heavy haze episodes. Based on ground monitoring data, satellite products and meteorological products of atmospheric pollutants in northeast China from 2013 to 2017, the characteristics of spatial and temporal distribution of air quality and the causes of heavy haze events in northeast China were discussed. It was found that the "Shenyang-Changchun-Harbin" city belt was the most polluted area in the region on an annual scale. The spatial distribution of air quality index (AQI) values had a clear seasonality, with the worst pollution occurring in winter, an approximately oval-shaped polluted area around western Jilin Province in spring, and the best air quality occurring in summer and most of autumn. The three periods that typically experienced intense haze events were Period I from late-October to early-November (i. e., late autumn and early winter), Period Ⅱ from late-December to January (i. e., the coldest time in winter), and Period Ⅲ from April to mid-May (i. e., spring). During Period I, strong PM 2.5 emissions from seasonal crop residue burning and coal burning for winter heating were the dominant reasons for the occurrence of extreme haze events (AQI>300). Period Ⅱ had frequent heavy haze events (200 < AQI < 300) in the coldest months of January and February(200 < AQI < 300), which were due to high PM 2.5 emissions from coal burning and vehicle fuel consumption, a lower atmospheric boundary layer, and stagnant atmospheric conditions. Haze events in Period Ⅲ, with high PM 10 concentrations, were primarily caused by the regional transportation of windblown dust from degraded grassland in central Inner Mongolia and bare soil in western Jilin Province. Local agricultural tilling could also release PM 10 and enhance the levels of windblown dust from tilled soil.

Organic aerosols have attracted increasing attention recently due to their significant contribution to fine particles (PM 2.5 ) and their complex components and sources. In this study, a total of 40 PM 2.5 samples were collected simultaneously with high-volume samplers in Changchun from 16 th Oct to 29 th Nov 2016. Organic carbon (OC), elemental carbon (EC), non-polar organic compounds including n -alkanes, polycyclic aromatic hydrocarbons (PAHs), and hopanes, and levoglucosan in atmospheric fine particles were analyzed. The main sources of organic aerosols were identified by molecular markers, diagnostic ratios, and a principal component analysis-multiple liner regression (PCA-MLR) model. The results showed that the average mass concentration of PM 2.5 was (79.0±55.7) μg·m -3 , and the averaged OC and EC mass concentrations were (20.7±15.6) μg·m -3 and (2.2±1.1) μg·m -3 , which accounted for 26.2% and 2.8% of PM 2.5 , respectively. The total average concentration of the tested non-polar organic compounds was (186.3±104.5) ng·m -3 and, in descending order, this was composed of n -alkane (101.3±67.0) ng·m -3 , polycyclic aromatic hydrocarbons (81.4±46.0) ng·m -3 , hopanes (3.8±1.9) ng·m -3 . The PCA-MLR model results showed that the relative contributions of the main sources of organic aerosols were coal combustion (47.0%), biomass burning (42.6%), and traffic emission (10.4%).

A mineral-based porous granulation material (MPGM) was prepared for absorbing the heavy metal ions from quartz processing wastewater. Analytic results of the MPGM were illustrated by the techniques of BET, SEM and FT-IR, which revealed the excellent properties of multi-aperture distribution, large specific surface area, low loss ratio and so on; the N2 adsorption-desorption isotherm was type-III with H4 hysteresis loop; the functional groups were dominated by groups of layer silicate mineral. A batch adsorption study was carried out with varied adsorbent dosage, initial pH and reaction time. The results showed that the residual ion concentrations of Fe, Zn, Mn and As were decreased from 77.760, 3.700, 2.789 and 0.963 mg x L(-1) to 3.421, 0.574, 0.126 and 0.034 mg x L(-1), respectively. MPGM might be re-utilized after desorption by 1.0 mol x L(-1) NaCl for 12 hours, and the ideal adsorption performance was maintained after 5 recyclings. The adsorption equilibrium and kinetics followed Langmuir and typical pseudo-first-order/pseudo-second-order adsorption models. Thermodynamic parameters of ΔG(θ) < 0, ΔHθ > 0, ΔSθ > 0 showed that the adsorptions were spontaneous and endothermic processes in the temperature range of 15-45 degrees C.