This study takes the Southern antimony smelting slag depot in Xikuangshan (XKS) Sb mine in the city of Lengshuijiang, Hunan, China, as the research object and explores the release law of Sb, As, and Hg in smelting slag under different pH-value simulated acid rain by a semi-dynamic leaching experiment of simulating the local rain. The results show that the leachate pH value is positively correlated with the pH value of simulated acid rain, while the leachate conductivity is negatively correlated with it. The leaching rates of As and Hg are negatively correlated with the pH value of the simulated acid rain, while the leaching rate of Sb is positively correlated with it; in the leaching process, the leachate pH value goes downward slowly after shooting up, but the leachate conductivity is continuously reduced; the releasing process of Sb, As, and Hg consists of two stages, and their leaching rate forms such an order as Sb > Hg > As. The diffraction peak intensity of the main mineral composition of quartz and calcite decreases significantly after leaching; the smelting slag’s surface becomes less rough than before leaching, with fewer pores and edges, and the contents of S, Si, Al, Fe, Ca, and Sb on the slag surface decrease while the content of O, As, and Hg increases.
The aim of this study was to assess initial effects of warming on the plant growth, soil nutrient contents, microbial biomass and enzyme activities of two most widespread ecosystem types: swamp meadow (deep soil, high water content) and alpine meadow (poor soil, low water content), in the hinterland of the Qinghai-Tibet Plateau (altitude 4600–4800 m a.s.l.) The temperature of air and upper soil layer was passively enhanced using open-top chambers (OTCs) (50 cm high with 60 cm at opening and constructed of 6 mm thick translucent synthetic glass) from 2006 to 2008. The use of OTCs clearly raised temperature and decreased soil moisture. In warmed plots, monthly mean air temperature was increased by 2.10oC and 2.28oC, soil moisture of 20 cm soil layer was decreased by 2.5% and 3.9% in alpine meadow and swamp meadow, respectively. Plant biomass significantly increased by 31% in alpine meadow and 67% in swamp meadow. Warming also affected soil microbial biomass C and N at both meadows. In swamp meadow, warming caused the decrease of soil organic carbon and total nitrogen in 0–5 cm layer and an increase in 5–20 cm. While in alpine meadow, these soil parameters increased in 0–5 cm layer and decreased in 5–20 cm layer. The effects of warming on enzyme activities differed depending on the enzyme and the meadow ecosystem. In general, enzyme activities were higher in the upper soil layers (0–5 cm) than in the lower soil layers (5–20 cm). The experiment results exhibited that warming improved the soil biochemical and microbiological conditions in high- mountain meadows, at least in the short term.
In order to properly understand the effect of freezing-thawing circle (FTC) to mechanical behavior of costal soft soil (CSS), unconfined compressive test is conducted. Six kind FTC times are designed from zero to five. The tested data show that: (1) unconfined compressive strength of CCS decreases nonlinearly with more FTC, and the strength after five FTC times becomes about 22% of its original strength without any freezing-thawing experience; (2) stressstrain curves of all unconfined compressive samples can be well fitted by three-parameter hyperbolic model; (3) and relationship between two parameters and FTC times can be fitted by exponent function, while another parameter can be considered as 0.95. Consequently, one composite hyperbolic- exponent empirical formula is established in order to describe freezing-thawing-dependent stress-strain behavior of CSS. Finally, good agreements have been found between tested dada and simulated results
Cracking is caused by physiological stress during the development of jujube fruit, and this causes considerable economic losses to fruit producers. The aim of this study was to clarify the mechanisms of water entry into the fruit and the events that lead to cracking. Differences in water absorption by fruit stalks and surfaces were observed in a cracking-sensitive variety (Ziziphus jujuba Mill. ‘Hupingzao’) and a cracking-resistant variety (Ziziphus jujuba Mill. ‘Yuanlingzao’). The response of the fruit surface to water absorption was studied, and the relationship between stomatal characteristics and cracking was analyzed. The cracking rate of ‘Hupingzao’ was higher during the coloring period. The relative amount of water absorbed through the fruit stalk of ‘Yuanlingzao’ after 10 h was 1.22 times higher than that of ‘Hupingzao’ during the coloring period. The rate of water absorption through the fruit surface of ‘Hupingzao’ was higher than that of ‘Yuanlingzao’ during the coloring period (3.73 and 3.04, respectively). Water was transported by the vascular bundle after entering the fruit through the fruit stalk, but was mainly distributed around the stomata of the epidermis and near-surface cells following entry through the fruit surface. After water was absorbed by the fruit surface, surface and stomatal cracks in ‘Hupingzao’ were apparent, and the degree of cracking of the stomata worsened with increasing water absorption time. The surface of ‘Yuanlingzao’ appeared cracked with increasing immersion time, but stomatal changes were not obvious. The stomatal size and aperture in the cracking-resistant variety of jujube fruit were lower than those in the cracking-sensitive variety. Stomatal size was positively correlated with the rate of fruit cracking. Water absorption through the surface was the main factor that induced fruit cracking. Stomatal characteristics, as well as the increased and deepened fruit surface microcracks caused by stomatal water absorption, were the primary factors related to cracking.
In order to demonstrate that silicate (SiO3-Si) can be used as an indicator to study upwelling in the northern South China Sea, hierarchical cluster analysis (CA) and principle component analysis (PCA) were applied to analyse the metrics of the data consisting of 14 physical-chemical-biological parameters at 32 stations. CA categorized the 32 stations into two groups (low and high nutrient groups). PCA was applied to identify five Principal Components (PCs) explaining 78.65% of the total variance of the original data. PCA found important factors that can describe nutrient sources in estuarine, upwelling, and non-upwelling areas. PC4, representing the upwelling source, is strongly correlated to SiO3-Si. The spatial distribution of silicate from the surface to 200 m depth clearly showed the upwelling regions, which is also supported by satellite observations of sea surface temperature.
The inhibin βB (INHBB) gene was studied as a candidate gene for the prolificacy of Jining Grey goats. According to the sequence of bovine INHBB gene, two pairs of primers were designed to detect single nucleotide polymorphism in exon 2 of INHBB gene in high-prolificacy (Jining Grey)and low-prolificacy (Inner Mongolia Cashmere and Angora) goats by polymerase chain reactionsingle strand conformation polymorphism method. Only the amplified products of primer P2 showed polymorphism. Three genotypes (AA, AB and BB) were identified in Jining Grey and two (AB and BB) in Inner Mongolia Cashmere and Angora goats. Sequencing revealed one single nucleotide mutation (A→G) at base 782 of exon 2 of INHBB gene in BB genotype compared to genotype AA.
Our study assessed the non-carcinogenic risks of heavy metals in the sources of drinking water treatment plants located along Huaihe River in Jiangsu Province, China. High-resolution inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectroscopy were used to determine the levels of eight metals in the water from 30 treatment plants. Non-carcinogenic risks induced by the metals were assessed using the methods recommended by the Environmental Protection Agency of the United States. Among the metals, Fe had the highest concentration and Pb contributed most to the average hazard index (HI) of 30 TWTPs. Except Pb, each metal had an average concentration below the permissible limit of China and the United States. The induced non-carcinogenic risks showed temporal and spatial variations. This study revealed that the metals in the tap water induced negligible public health risks for local residents.
Thallium (Tl) is a typical trace metal of extreme high toxicity. As a concomitant element, Tl is widely found in various sulfide minerals and K-containing rock minerals. The outburst of Tl pollution in drinking water sources of the northern branch of the Pearl River in China as reported in 2010 has greatly aroused public concerns about Tl pollution in China. Apart from typical sources of Tl pollution such as Pb and Zn smelting and the mining and utilization of Tl-containing pyrite ores, the steel-making industry was discovered a new significant source that contributed to this Tl pollution incidence. Thallium contents in raw materials, fly ash and wastewater collected from a typical steel-making enterprise were determined by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that Tl contents (0.02-1.03 mg/kg) are generally low in the raw materials, while fly ash samples have generally enriched Tl levels (1.31-6.45 mg/kg). Wastewater obtained from the dedusting process of the sintering furnace also exhibited excessive Tl levels (574-2130 μg/L). All these results suggested a possible release and gasification of Tl compounds from the raw materials under high temperatures (>800ºC) during the sintering processes, which were then accumulated in the flue gas and fly ash and washed into the wastewater by wet dedusting. Lime precipitation method is not effective for removing Tl from wastewater, since Tl mostly is present as dissolved Tl⁺ in the water. The study initiated a preliminary design of a fast and effective treatment method for Tl removal from Tl-containing industrial wastewater by using a deep oxidation system.
The polymorphisms of arylalkylamine-N-acetyltransferase (AA-NAT) gene in high-prolificacy Jining Grey goat, medium-prolificacy Boer goat and low-prolificacy Liaoning Cashmere, Inner Mongolia Cashmere and Angora goats were detected to analyse their relationships with litter size.Primers (P1-P5) were designed to detect the polymorphisms by PCR-SSCP and PCR-RFLP. For P2,AA, AB and BB genotypes were detected. Sequencing revealed one silent mutation (T132C) of AANAT gene in BB in comparison to AA. For P3, CC and CD genotypes were detected and sequencing revealed one mutation (C265T) of AA-NAT gene in CD in comparison to CC, and this mutation resulted in an amino acid change of Arg→Cys (R89C). The Jining Grey does with genotype CD delivered by 0.56 kids (P<0.05) more than those with CC genotype. For P5, EE, EF and FF genotypes were detected and sequencing revealed one mutation (C586T) of AA-NAT gene in FF in comparison to EE. This mutation caused an amino acid change of Arg→Trp (R196W). For both P2 and P5, the differences in litter size among three genotypes were not significant in Jining Grey goats (P>0.05).These results preliminarily indicate that allele D at the C265T locus of AA-NAT gene is a potential marker in genetic improvement of litter size in goats.
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