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1

Numerical simulation and experimental study on formation of high concentration of H2 generated by gas explosion

100%
Lei B., Wu B., Zhao Y., Ashraf M. A.
Polish Maritime Research
|
2016
|
tom 23
|
nr Special Issue S1
In coal mine fire rescues, if the abnormal increase of gas concentration occurs, it is the primary thing to analyze the reasons and identify sources of the abnormal forming, which is also the basis of judge the combustion state of fire area and formulate proper fire reliefs. Nowadays, related researches have recognized the methane explosion as the source of high concentration of H2 formation, but there are few studies about the conditions and reaction mechanism of gas explosion generating high concentration of H2.Therefore, this paper uses the chemical kinetic calculation software, ChemKin, and the 20L spherical explosion experimental device to simulate the generating process and formation conditions of H2 in gas explosion. The experimental results show that: the decomposition of water vapor is the main base element reaction (R84) which leads to the generation of H2.The free radical H is the key factor to influence the formation of H2 generated from gas explosion. With the gradual increase of gas explosion concentration, the explosive reaction becomes more incomplete, and then the generating quantity of H2 increases gradually. Experimental results of 20L spherical explosion are consistent with the change trend about simulation results, which verifies the accuracy of simulation analysis. The results of explosion experiments show that when gas concentration is higher than 9%, the incomplete reaction of methane explosion increases which leads to the gradual increase of H2 formation
2

Assessment of heavy metal contamination from sediment and soil in the riparian zone China’s Three Gorges Reservoir

100%
Wang Y., Ao L., Lei B., Zhang S.
Polish Journal of Environmental Studies
|
2015
|
tom 24
|
nr 5
In the Three Gorges Reservoir (TGR), sedimentation of the riparian zone has occurred over the past 10 years. However, the sediment and related environmental effects have not been explored well. In the present study, sediment and soil in situ were collected in three sites of the riparian zone in the TGR. Samples were analyzed for water content, bulk density, pH, organic matter, total nitrogen, total phosphorus, and heavy metals (As, Cr, Cu, Ni, Pb, Zn). Results revealed that, compared with soil, water content, organic matter, and total phosphorus of sediment were high while bulk density was low. Heavy metal concentrations (As, Cu, Pb, Zn) in sediment were significantly higher than those in soil. Sediment was moderately polluted by Cu and Pb, and soil was unpolluted-moderately polluted by As and Cu. Moreover, the individual and comprehensive potential ecological risk of heavy metals from both sediment and soil showed a low degree. Enrichment of nutrients and heavy metals in sediment of the riparian zone are probably of formation regime and anthropogenic activities, and could pose risks to the environment and human health. Therefore, enhanced efforts of soil and water conservation and pollution treatment in the upper stream of the Yangtze River and the TGR area should be recommended.
3

Effects of salt-tolerant rootstock grafting on ultrastructure, photosyntetic capacity, and H2O2-scavening system in chloroplasts of cucumber seedling under NaCl stress

88%
Zhen A., Bie Z., Huang Y., Liu Z., Lei B.
Acta Physiologiae Plantarum
|
2011
|
tom 33
|
nr 6
Plant growth, photosynthetic parameters, chloroplast ultrastructure, and the ascorbate-glutathione cycle system in chloroplasts of self-grafted and rootstock-grafted cucumber leaves were investigated. Grafted plants were grown hydroponically and were exposed to 0, 50, and 100 mM NaCl concentrations for 10 days. Under NaCl stress, the hydrogen peroxide (H₂O₂) content in cucumber chloroplasts increased, the chloroplast ultrastructure was damaged, and the gas stomatal conductance, intercellular CO₂ concentration, as well as shoot dry weight, plant height, stem diameter, leaf area, and leaf relative water content were inhibited, whereas these changes were less severe in rootstock-grafted plants. The activities of ascorbate peroxidase (APX; EC 1.11.1.11), glutathione reductase (GR; EC 1.6.4.2), and dehydroascorbate reductase (DHAR EC 1.8.5.1) were higher in the chloroplasts of rootstock-grafted plants compared with those of self-grafted plants under 50 and 100 mM NaCl. Similar trends were shown in leaf net CO₂ assimilation rate and transpiration rate, as well as reduced glutathione content under 100 mM NaCl. Results suggest that rootstock grafting enhances the H₂O₂-scavenging capacity of the ascorbate–glutathione cycle in cucumber chloroplasts under NaCl stress, thereby protecting the chloroplast structure and improving the photosynthetic performance of cucumber leaves. As a result, cucumber growth is promoted.
4

Identification and expression analysis of APETALA1 homologues in poplar

76%
Chen Z., Yang X., Su X., Rao P., Gao K., Lei B., An X.
Acta Physiologiae Plantarum
|
2015
|
tom 37
|
nr 03
APETALA1 plays a crucial role in floral transition from vegetative to reproductive phase and in flower development. In this study, a comprehensive analysis of AP1 homologues in poplar was performed by describing the gene structure and chromosomal location. The phylogenetic relationship of the deduced amino acid sequences of Arabidopsis AP1 and AP1 homologues from Populus, to other AP1-like proteins was analyzed. The expression of PtAP1-1 and PtAP1-2 in Populus tomentosa was examined by RT-qPCR. Expression profiles were similar and both genes exhibited a high expression level in the reproductive phase. Seasonal expression profiles in floral buds indicated that the pattern of PtAP1-1 and PtAP1-2 expression in male and female floral buds was different. The trends of the PtAP1-1 and PtAP1-2 transcript levels in both sex floral buds were similar, but the peak of expression of the two genes in male buds was earlier than in female buds. This work would be of value to future functional analysis of AP1 homologues in poplar.
5

Rootstocks improve cucumber photosynthesis through nitrogen metabolism regulation under salt stress

76%
Liu Z., Bie Z., Huang Y., Zhen A., Niu M., Lei B.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 07
We examined the growth, photosynthetic parameters, initial and total ribulose-1,5-bisphosphate carboxylase/ oxygenase (Rubisco) activity, the relative expression of rbcL, rbcS, and rca gene, and nitrogen metabolism of cucumber (Cucumis sativus L. cv. Jinchun No.2, CS) plants grafted onto figleaf gourd (Cucurbita ficifolia Bouche´, CF) and pumpkin (Cucurbita moschata Duch. cv. Chaojiquanwang, CM) rootstocks. Growth inhibition under salt stress (90 mM NaCl) was characterized by the irreversible inhibition of CO2 assimilation in the cucumber plants grafted onto cucumber rootstocks (CS/ CS). In contrast, this effect was significantly alleviated by grafting the cucumber plants onto the CF and CM roots (CS/CF, CS/CM). Under NaCl stress, the CS/CF and CS/ CM plants exhibited higher photosynthetic activity, higher initial and total Rubisco activity, and higher Rubiscorelated gene expression than the CS/CS plants. Salinity resulted in a lesser increase in nitrate content and decrease in free amino acid content in the CS/CF and the CS/CM plants compared with the CS/CS plants. Accordingly, the activity of nitrate reductase, glutamine synthetase, and glutamate synthase decreased significantly, especially in the CS/CS plants. These results suggest that grafting cucumber plants onto salt-tolerant rootstocks enhances Rubisco activity and the expression of Rubisco-related genes by effectively accelerating nitrate transformation into amino acids under NaCl stress, thereby improving the photosynthetic performance of cucumber leaves.
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