Stannate-Based Materials as Anodes in Lithium-Ion and Sodium-Ion Batteries: A Review.

Binary metal oxide stannate (M2SnO4; M = Zn, Mn, Co, etc.) structures, with their high theoretical capacity, superior lithium storage mechanism and suitable operating voltage, as well as their dual suitability for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), are strong candidates for next-generation anode materials. However, the capacity deterioration caused by the severe volume expansion problem during the insertion/extraction of lithium or sodium ions during cycling of M2SnO4-based anode materials is difficult to avoid, which greatly affects their practical applications. Strategies often employed by researchers to address this problem include nanosizing the material size, designing suitable structures, doping with carbon materials and heteroatoms, metal-organic framework (MOF) derivation and constructing heterostructures. In this paper, the advantages and issues of M2SnO4-based materials are analyzed, and the strategies to solve the issues are discussed in order to promote the theoretical work and practical application of M2SnO4-based anode materials.

[Effect of Biomass Burning on the Light Absorption Properties of Water Soluble Organic Carbon in Atmospheric Particulate Matter in Changchun].

To investigate the effect of biomass burning in Changchun in autumn on the absorbance of water-soluble organic carbon (WSOC) on PM2.5, PM2.5 samples were collected from October to November 2017. The light absorption characteristics of WSOC, carbonaceous components, and carbohydrate content in PM2.5 were analyzed. The study showed that the average concentrations of WSOC, organic carbon (OC), and elemental carbon (EC) in PM2.5 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) m2·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%.

[Research progress and ecological roles of phytoplankton cysts]. / æµ®æ¸¸æ¤ç‰©å­¢å›Šçš„ç ”ç©¶è¿›å±•ä¸Žç”Ÿæ€æ„ä¹‰.

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.

[Spatial and Temporal Characteristics of Air Quality and Cause Analysis of Heavy Pollution in Northeast China].

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 PM2.5 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 PM2.5 emissions from coal burning and vehicle fuel consumption, a lower atmospheric boundary layer, and stagnant atmospheric conditions. Haze events in Period Ⅲ, with high PM10 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 PM10 and enhance the levels of windblown dust from tilled soil.

[Molecular Composition and Source Apportionment of Fine Organic Aerosols in Autumn in Changchun].

Organic aerosols have attracted increasing attention recently due to their significant contribution to fine particles (PM2.5) and their complex components and sources. In this study, a total of 40 PM2.5 samples were collected simultaneously with high-volume samplers in Changchun from 16th Oct to 29th 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 PM2.5 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 PM2.5, 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%).

Chemical characteristics of dicarboxylic acids and related organic compounds in PM2.5 during biomass-burning and non-biomass-burning seasons at a rural site of Northeast China.

Fine particulate matter (PM2.5) samples were collected using a high-volume air sampler and pre-combusted quartz filters during May 2013 to January 2014 at a background rural site (47∘35 N, 133∘31 E) in Sanjiang Plain, Northeast China. A homologous series of dicarboxylic acids (C2-C11) and related compounds (oxoacids, α-dicarbonyls and fatty acids) were analyzed by using a gas chromatography (GC) and GC-MS method employing a dibutyl ester derivatization technique. Intensively open biomass-burning (BB) episodes during the harvest season in fall were characterized by high mass concentrations of PM2.5, dicarboxylic acids and levoglucosan. During the BB period, mass concentrations of dicarboxylic acids and related compounds were increased by up to >20 times with different factors for different organic compounds (i.e., succinic (C4) acid > oxalic (C2) acid > malonic (C3) acid). High concentrations were also found for their possible precursors such as glyoxylic acid (ωC2), 4-oxobutanoic acid, pyruvic acid, glyoxal, and methylglyoxal as well as fatty acids. Levoglucosan showed strong correlations with carbonaceous aerosols (OC, EC, WSOC) and dicarboxylic acids although such good correlations were not observed during non-biomass-burning seasons. Our results clearly demonstrate biomass burning emissions are very important contributors to dicarboxylic acids and related compounds. The selected ratios (e.g., C3/C4, maleic acid/fumaric acid, C2/ωC2, and C2/levoglucosan) were used as tracers for secondary formation of organic aerosols and their aging process. Our results indicate that organic aerosols from biomass burning in this study are fresh without substantial aging or secondary production. The present chemical characteristics of organic compounds in biomass-burning emissions are very important for better understanding the impacts of biomass burning on the atmosphere aerosols.

Neuroprotection of Cilostazol against ischemia/reperfusion-induced cognitive deficits through inhibiting JNK3/caspase-3 by enhancing Akt1.

Cilostazol(CTL) is a phosphodiesterase inhibitor, which has been widely used as anti-platelet agent. It also has preventive effects on various central nervous system (CNS) diseases, including ischemic stroke, Parkinson's disease and Alzheimer disease. However, the molecular mechanism underlying the protective effects of CTL is still unclear, and whether CTL can prevent I/R induced cognitive deficit has not been reported. Transient global brain ischemia was induced by 4-vessel occlusion in adult male Sprague-Dawley rats. The open field tasks and Morris water maze were used to assess the effect of CTL on anxiety-like behavioral and cognitive impairment after I/R. Western blotting were performed to examine the expression of related proteins, and HE-staining was used to detect the percentage of neuronal death in the hippocampal CA1 region. Here we found that CTL significantly improved cognitive deficits and the behavior of rats in Morris water maze and open field tasks (P<0.05). HE staining results showed that CTL could significantly protect CA1 neurons against cerebral I/R (P<0.05). Additionally, Akt1 phosphorylation levels were evidently up-regulated (P<0.05), while the activation of JNK3, which is an important contributor to I/R-induced neuron apoptosis, was reduced by CTL after I/R (P<0.05), and caspase-3 levels were also decreased by CTL treatment. Furthermore, all of CTL's protective effects were reversed by LY294002, which is a PI3K/Akt1 inhibitor. Taken together, our results suggest that CTL could protect hippocampal neurons and ameliorate the impairment of learning/memory abilities and locomotor/ exploratory activities in ischemic stroke via a PI3K-Akt1/JNK3/caspase-3 dependent mechanism.

The complete mitochondrial genome of the Fossorochromis rostratus.

The Fossorochromis rostratus is a species of cichlid endemic to Lake Malawi in East Africa. In this study, we first reported the complete mitochondrial genome of F. 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 to Astatotilapia 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 of F. rostratus and its phylogenic relationship with other related species would facilitate our understanding of the evolution of Cichlidae mitochondrial genome.

Inorganic markers, carbonaceous components and stable carbon isotope from biomass burning aerosols in Northeast China.

To better characterize the chemical compositions and sources of fine particulate matter (i.e. PM2.5) in Sanjiang Plain, Northeast China, total carbon (TC), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and inorganic ions as well as stable carbon isotopic composition (δ13C) were measured in this study. Intensively open biomass burning episodes are identified from late September to early October by satellite fire and aerosol optical depth maps. During the biomass-burning episode, concentrations of PM2.5, OC, EC, and WSOC are increased by a factor of 4-12 compared to those during the non-biomass-burning period. Non-sea-salt potassium is strongly correlated with PM2.5, OC, EC and WSOC, demonstrating an important contribution from biomass-burning emissions. The enrichment in both the non-sea-salt potassium and chlorine is significantly larger than other inorganic species, suggesting that biomass-burning aerosols in Sanjiang Plain are mostly fresh and less aged. In addition, the WSOC-to-OC ratio is lower than that reported in biomass-burning aerosols in tropical regions, further supporting that biomass-burning aerosols in Sanjiang Plain are mostly primary and secondary organic aerosols may be not significant. A lower average δ13C value (-26.2‰) is observed during the biomass-burning period, indicating a dominant contribution from combustion of C3 plants in the studied region.

[Purification of the wastewater of quartz processing by mineral-based porous granulation material].

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.