摘要:
Microbial Induced Calcium Carbonate Precipitation (MICP) has some disadvantages, such as low crystallization conversion rate of calcium carbonate and insufficient strength properties of tailings. In this paper, a modified method combining soft template calcium carbonate mineralization technology with microbial grouting reinforcement technology was proposed. The tailings solidification was studied with the control of nine different concentrations of egg white (0%, 5%, 10%, 15%, 20%, 30%, 40%, 60% and 80%). After 14 days of grouting reinforcement experiment, the results are as follows. (1) The shear strength of tailings was improved remarkably, and the best reinforcement effect was at 5% egg white. Compared with the control group, the effective cohesion of tailings increased by 437.61%. (2) The fitting curve between the content of calcium carbonate in tailings and its cohesion shows that there is an exponential relationship between them. (3) The results of microscopic examination showed that the proportion of columbite-type calcium carbonate increased with the increase of egg white concentration. The corresponding egg white concentration of calcite-type calcium carbonate was 5%. At this time, the maximum particle size could reach 100 mu m. (4) The infrared absorption characteristic curves of the interporous cements of tailings indicate that the changes of crystal form, crystal morphology and particle size of calcium carbonate may be due to the strong interaction between polar groups such as N-H, C-H and C=O in the composition of egg white and calcium carbonate crystal. (5) The bonding, connecting and packaging of fibers in egg white will cause fundamental changes in the bonding mode of tailings. The test results showed that the combination of mineralization regulation of egg white and MICP technology can achieve complementary advantages, which is of great engineering significance for improving the stability and safety of tailings dam. (C) 2020 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society.
通讯机构:
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, Hunan Province Key Laboratory of Green Development Technology for Extremely Low Grade Uranium Resources, University of South China, Hengyang, China
摘要:
In this paper, the developmental toxicity and apoptosis in zebrafish (Danio rerio) embryos induced by 0.01, 0.05, and 0.10-Gy gamma-ray irradiation were investigated and verified by single cell gel electrophoresis, acridine orange staining, flow cytometry, transmission electron microscopy, digital gene expression sequencing, and Western blot analysis. DNA damage, deformity rates, and apoptosis of zebrafish embryos were found to increase significantly with the increase of irradiation dose, and survival and hatching rates significantly decreased when the irradiation dose exceeds 0.10 and 0.05 Gy, respectively. Exposure to 0.10-Gy gamma-ray irradiation resulted in the swelling of cell mitochondria of zebrafish embryos and changes in their intracellular vacuoles. mRNA and protein expression levels of Shh (sonic hedgehog 19 KDa) and Smo (smoothened 86 KDa) of Hh signaling pathway associated with the development of early embryos significantly increased with the increase of irradiation dose. Expression of the AKT (56 KDa) and PiK3r3 (55 KDa) genes, which are anti-apoptotic and involved with the PI3K/Akt signaling pathway, significantly decreased, while expression of the bada gene, which is pro-apoptotic, significantly increased. The results show that gamma-ray irradiations of 0.01 and 0.05 Gy can induce developmental toxicity and apoptosis in zebrafish embryos via Hh and PI3K/Akt signaling pathways, respectively.
摘要:
Gamma radiation causes cell injury and leads to an increased risk of cancer, so it is of practical significance to identify biomarkers for gamma radiation. We used proteomic analysis to identify differentially expressed proteins in liver tissues of C57BL/6J mice treated with gamma radiation from 137Cs for 360 d. We confirmed obvious pathological changes in mouse liver tissues after irradiation. Compared with the control group, 74 proteins showed a fold change of ≥1.5 in the irradiated groups. We selected 24 proteins for bioinformatics analysis and peptide mass fingerprinting and found that 20 of the identified proteins were meaningful. These proteins were associated with tumorigenesis, tumor suppression, catalysis, cell apoptosis, cytoskeleton, metabolism, gene transcription, T-cell response, and other pathways. We confirmed that both cofilin-1 and destrin were up regulated in the irradiated groups by western blot and real-time polymerase chain reaction. Our findings indicate that cofilin-1 and destrin are sensitive to gamma radiation and may be potential biomarkers for gamma radiation. Whether these proteins are involved in radiation-induced tumorigenesis requires further investigation.
摘要:
A greenhouse pot experiment was performed to investigate the enhancement of repeated applications of citric acid (CA), ethylenediamine disuccinic acid (EDDS), and Oxalic acid (OA) on phytoremediation of uranium (U) contaminated soil by Macleaya Cordata. The chelates followed the order CA > EDDS > OA in terms of the enhancement on uranium uptake by M. cordata. The repeated applications of the chelates were found to be more effective than the one time application at the equal dose as the U concentration of soil solution increased significantly from the 8th to 14th day. The repeated applications of 10 mmol kg(-1) CA promoted the solubilization of U in the U-contaminated soil by significantly decreasing the pH of soil solution, achieved the maximum U concentration of soil solution (1463.6 microg L(-1)), bioconcentration factors (BCFs, 11.4), bioaccumulation factors (BAFs, 21.4) and transfer factors (TFs, 1.9), which were 215.2, 5.7, 30.6 and 16.3 times as compared with the control group, respectively. The three applied chelates significantly affected the activities of the antioxidant enzymes in the leaves. Repeated applications of CA further enhanced the activities of the antioxidant enzymes in the leaves of M. cordata as compared with the control, EDDS and OA, mitigated the oxidative stress induced by uranium and chelates, and maximized the enhancement on the uranium uptake, which will be beneficial for the enhancement on the phytoremediation of uranium contaminated soil by U hyperaccumulating plants. These results indicated that the phytoavailability of uranium in soil solution as well as the accumulation of U by M. cordata were both significantly increased after repeated applications of CA, and that the repeated applications of 10 mmol kg(-1) CA increased the activities of the antioxidant enzymes and promoted U accumulation by M. cordata. The study provided an environmentally friendly alternative for the enhancement on the phytoremediation of uranium contaminated soil using M. cordata.
期刊:
北京理工大学学报,2018年38(3):300-304 and 312 ISSN:1001-0645
作者机构:
[宁志刚; 郝光鹏; 程雄; 沈文斌] College of Electrical Engineering, University of South China, Hengyang;Hunan;421001, China;[丁德馨] School of Nuclear Resource Engineering, University of South China, Hengyang;[宁志刚; 郝光鹏; 程雄; 沈文斌; 丁德馨] Hunan
摘要:
The radon exhalation rate and transfer radon velocity between liquid and gas under different temperature and humidity conditions are investigated. The fitting formulas of radon exhalation rate and temperature and humidity are exponential functions, and each exponent is a 2nd-order polynomial. The fitting formula of transfer radon velocity and temperature is Boltzmann function, and the velocity tends to be stable gradually at 25 °C. The fitting formula of transfer radon velocity and humidity is exponential function whose exponent is a 2nd order polynomial, and the velocity increases at first when the humidity was 0.75, then decreases with increasing humidity.
作者:
Yi, Lingzhi;Deng, Xianjun*;Zou, Zenghui;Ding, Dexin;Yang, Laurence T.
期刊:
Journal of Parallel and Distributed Computing,2018年118(Pt.1):57-66 ISSN:0743-7315
通讯作者:
Deng, Xianjun
作者机构:
[Yi, Lingzhi] Univ South China, Sch Civil Engn, Hengyang, Hunan, Peoples R China.;[Zou, Zenghui; Deng, Xianjun] Univ South China, Dept Commun Engn, Hengyang, Hunan, Peoples R China.;[Ding, Dexin] Univ South China, Sch Environm Protect & Safety Engn, Hengyang, Hunan, Peoples R China.;[Deng, Xianjun] St Francis Xavier Univ, Antigonish, NS, Canada.;[Yang, Laurence T.] St Francis Xavier Univ, Dept Comp Sci, Antigonish, NS, Canada.
通讯机构:
[Deng, Xianjun] U;Univ South China, Hengyang, Hunan, Peoples R China.
关键词:
Confident information coverage;Coverage hole detection;Sensor networks;Cyber-enabled applications
摘要:
The wireless sensor networks recently abstract great attention and are used for a wide range of cyberenabled applications each of which with rigid accuracy requirements. The emergence and existence of coverage holes in WSNs will dramatically degrade the network coverage performance and quality of service. To diminish the negative effects of coverage holes, this paper addresses and studies the confident information coverage hole detection problem (CICHD) based on the proposed novel confident information coverage model (CIC). For solving the CICHD problem, we design two effective heuristic CIC holes detection algorithms including the CHD without considering the nodes residual energy and the other CHDRE taking the nodes' residual energy into account. In the both proposed algorithms, the sensing field is firstly partitioned into a series of reconstruction grids based on the spatial correlation and correlation range. Then each reconstruction grid will be scanned and detected based on the CIC model to be judged whether it is a hole. Once obtaining the coverage status of every reconstruction grid, the boundary of the coverage hole will be exacted by image processing method. The results of the simulations show that both the proposed schemes can efficiently detect the emerged coverage holes including the locations and the number, and the CHDRE algorithm is more practical and efficient compared to the CHD without considering the energy problem. (C) 2017 Elsevier Inc. All rights reserved.
通讯机构:
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China
通讯机构:
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China
通讯机构:
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China