摘要：
The safety and stability of roadways is greatly influenced by the complex geological conditions present in the Sanmenxia Bauxite Mine, Henan Province, China. In this study, based on data from field survey, advanced detection methods, numerical studies, and monitoring studies, we have adopted the method of steel fiber-reinforced shotcrete to improve the excavation rate of roadways and guarantee the safety of the tunnel when it passes through unfavorable geological bodies, such as shale rocks and broken argillaceous limestone. Field surveys showed that the stability of roof rocks is the major problem faced by engineers; however, tunnel construction using cast-in-situ concrete, which is the method currently applied, costs too much time, resulting in an excavation rate that is too slow to meet the requirements of the Sanmenxia Bauxite Mine. Here, we propose an optimized scheme which, when combined with numerical simulations and data from advanced detection techniques and field monitoring surveys, can improve the efficiency of roadway roof support. During the implementation of the new scheme, the geological anomalies ahead of the working face were detected in advance. It is assumed that the supporting effect of the steel fiber-reinforced shotcrete is equivalent to that of the cast-in-situ concrete as long as a certain thickness is reached. Moreover, the steel fiber-reinforced shotcrete has better mechanical properties than cast-in-situ concrete and achieves a better combination effect with surrounding rock masses. Based on geological conditions and numerical results, the shotcrete should be thickest in the middle area along the roadway axis passing through the unfavorable geological bodies, and gradually become less thick from the middle to both ends. Field tests were carried out to verify the effectiveness of the scheme. The monitoring results show that the roadway passing through broken argillaceous limestone was stable after being supported by shotcrete (at least 80 mm); its thickness should reach at least about 120 mm when passing through shale rock mass. The results indicate that the use of steel fiber-reinforced shotcrete can considerably shorten the construction time compared with cast-in-situ concrete support. The scheme has proved to be a feasible, economical, and time-saving method for underground excavation in the Sanmenxia Bauxite Mine.
摘要：
A molecularly imprinted electrochemical sensor for the rapid detection of the anti-parasitic drug Secnidazole (SCZ) is reported. In this work, the build electrochemical sensor was based on a carbon paste electrode (CPE) modified with multi-wall carbon nanotubes (MWCNTs) and boron-embedded duplex molecularly imprinted composite membranes (B-DMICMs), that significantly increased the efficiency of the sensor for the detection of template molecule SCZ. Density functional theory (DFT) was employed to study the interactions between the template and monomers to select appropriate functional monomers for rational design of the B-DMICMs.The optimal experimental conditions were optimised for the factors affecting the performance of the sensor. Under the optimal conditions, the reduction peak currents of SCZ by differential pulse voltammetry increased linearly with SCZ concentration in the range from 3.0 x 10(-4) to 1.0 x 1.0(-6) mol L-1 and 1.0 x 1.0(-6) to 1.91 x 10(-8) mol L-1 with a detection limit of 1.72 x 10(-8) mol L-1 for secnidazole, which is significantly lower than those in the currently used methods and in previous reports. This method offers low cost, sensitive and effective determination of SCZ and can potentially be used for detection of SCZ in pharmaceutical and biological samples with good precision and accuracy.
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.
关键词：
deep learning;convolutional neural network;tree species classification;random forest;OHS-1 hyperspectral image
摘要：
The accurate characterization of tree species distribution in forest areas can help significantly reduce uncertainties in the estimation of ecosystem parameters and forest resources. Deep learning algorithms have become a hot topic in recent years, but they have so far not been applied to tree species classification. In this study, one-dimensional convolutional neural network (Conv1D), a popular deep learning algorithm, was proposed to automatically identify tree species using OHS-1 hyperspectral images. Additionally, the random forest (RF) classifier was applied to compare to the algorithm of deep learning. Based on our experiments, we drew three main conclusions: First, the OHS-1 hyperspectral images used in this study have high spatial resolution (10 m), which reduces the influence of mixed pixel effect and greatly improves the classification accuracy. Second, limited by the amount of sample data, Conv1D-based classifier does not need too many layers to achieve high classification accuracy. In addition, the size of the convolution kernel has a great influence on the classification accuracy. Finally, the accuracy of Conv1D (85.04%) is higher than that of RF model (80.61%). Especially for broadleaf species with similar spectral characteristics, such as Manchurian walnut and aspen, the accuracy of Conv1D-based classifier is significantly higher than RF classifier (87.15% and 71.77%, respectively). Thus, the Conv1D-based deep learning framework combined with hyperspectral imagery can efficiently improve the accuracy of tree species classification and has great application prospects in the future.
摘要：
The mass production of municipal solid waste incineration (MSWI) fly ashes has caused severe concerns in regarding to the inherently ecological harm and the decreasing landfilling space. To relieve the heavy metal contamination into the environment and complete a closed-loop electrokinetics (EK), the sequential effects of electrokinetics and alkali activating solidification/stabilization (S/S) technique on the immobilization of HMs in the remnant of MSWI fly ashes were investigated in the research. The compressive strength for the remnant-based solidified product at the proposing time of 18 days was 2.58MPa, 104.76% higher than that of the MWSI-based specimen with the optimal curing parameters being adopted for the production of the solidified matrices. The leaching concentrations of Zn, Pb, and Cu were 9.74, 0.21, and 0.75mg/L, correspondingly reduced by 57.84%, 80.19%, and 17.58%, respectively. The opposite correlation between the compressive strength and the leaching concentration was demonstrated for both two groups of the curing samples. The mechanism results showed that the electrokinetics had significantly changed the micromorphology characteristics of MSWI fly ashes and distinctly affected the whole curing process. The cementation and geo-polymerization were comprehensively determined as two of main mechanisms for the immobilization of HMs in the curing matrices.
摘要：
A dually responsive fluorescent probe for determination of U(IV) and mercury(II) ions was synthesized. The probe consists of a cytosine-rich hairpin DNA loaded with silver nanoclusters (DNA-AgNCs). The fluorescence of the AgNCs is found to be quenched by UO2(II) at pH 5.0 and Hg(II) at pH 7.0 due to combined static and dynamic quenching. Under the optimal conditions, the green fluorescence of the DNA-AgNCs, best measured at excitation/emission wavelengths of 420/525 nm, decreases in the 4.0 to 75 pM UO2(II) concentration range, and in the 0.3 to 8.0 nM Hg(II) concentration range. The respective detection limits are as low as 1.8 pM and 0.1 nM. The method was successfully applied to the determination of UO2(II) and Hg(II) in (spiked) pond and taps waters and in soil extracts. Graphical abstractA label-free DNA was designed to synthesize green-fluorescent silver nanoclusters (AgNCs) and used for rapid dual detection of uranyl ions (UO2(II)) at pH 5.0 and of mercury ions (Hg(II)) at pH 7.0 in environmental samples.
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.
期刊：
Journal of Environmental Radioactivity,2019年208:106036 ISSN：0265-931X
通讯作者：
Ding, De-xin
作者机构：
[Chen, Si-yu; Dai, Zhong-ran; Zhang, Hui; Hu, Nan; Sha, Yin-hua; Ding, De-xin] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Henyang 421001, Peoples R China.;[Zou, Chao; Wang, Yong-dong] Univ South China, Hunan Prov Key Lab Green Dev Technol Exetremely L, Henyang 421001, Peoples R China.;[Ding, De-xin] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, 28 West Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ding, De-xin] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, 28 West Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
关键词：
Artificial plant community plot;Contaminated soil;Enhanced phytoremediation;Uranium
摘要：
In order to develop an artificially constructed plant community plot for the enhanced phytoremediation of uranium contaminated soils, three uranium accumulators including Bamboo-willow (Salix sp.), Paspalum scrobiculatum linn and Macleaya cordata were used to construct four artificial plant community plots, and greenhouse experiments were conducted to investigate the bioaccumulation of uranium by the plants and the organic acid content, enzyme activity, and the change of microbial community structure in their rhizosphere soils. The transfer factor (TF) and the total bioaccumulation amount (TBA) of uranium were used to describe remediation efficiencies in this paper. It was found that their remediation efficiencies were in the order Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata > Bamboo-willow (Salix sp.)-Macleaya cordata > Paspalum scrobiculatum linn-Macleaya cordata > Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn. The bioaccumulation amount of uranium by each plant in the Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata community plot was significantly (P < 0.05) higher than that by its single population, the bioaccumulation amounts of uranium by Bamboo-willow (Salix sp.), Paspalum scrobiculatum linn and Macleaya cordata were 0.29, 0.32 and 2.19 mg/plant, respectively, and they were increased by 31.82%, 77.78% and 146.07%, respectively, and the transfer efficiencies by the plants were increased by 150%, 110% and 52.17%, respectively. The interaction between the plants' roots and the microorganisms in the rhizosphere soil of the Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata community plot resulted in the high content of organic acids such as oxalic acid in the rhizosphere soil of the plant community plot, which was significantly (P < 0.05) higher than that of its single population. The chelation of the organic acids with uranium led to an increase in the proportion of exchangeable uranium in soil solution. In addition, Burkholderia, which is an iron-producing carrier bacterium and can increase the uptake and accumulation of uranium by plants, and Leptolyngbya, which is a plant growth promoting rhizobacteria and can increase the biomass of plants, emerged in the rhizosphere soil of the plant community plot. These may be the mechanisms by which the phytoremediation of the uranium contaminated soils was enhanced by the plant community plot.
作者：
Ye, Yong-jun*;Xia, Xiang-qian;Dai, Xin-tao;Huang, Chun-hua;Guo, Qian
期刊：
Journal of Radioanalytical and Nuclear Chemistry,2019年320(2):369-375 ISSN：0236-5731
通讯作者：
Ye, Yong-jun
作者机构：
[Xia, Xiang-qian; Dai, Xin-tao; Ye, Yong-jun; Guo, Qian] Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.;[Huang, Chun-hua] Univ South China, Sch Architecture, Hengyang 421001, Hunan, Peoples R China.;[Ye, Yong-jun] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ye, Yong-jun] U;Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.
关键词：
The solubility of radon;Temperature;Salinity;pH;In-situ leaching mine
摘要：
To obtain the relationship between radon solubility and temperature, salinity, and pH of radon-bearing water in in situ leaching uranium mines, an experimental device for measuring the radon solubility in water was designed and manufactured. According to the range of temperature range, salinity, and pH of radon-containing radioactive water from in situ leaching mines in China, aqueous radon solubilities at different temperatures and salinities were determined using an orthogonal design and, concurrently, radon solubilities at different pH also determined. An empirical equation for estimating the radon solubility in radioactive water containing radon in uranium mining and metallurgy is proposed.
会议主办单位：
[Huang, Tao;Liu, Longfei;Wu, Shilu] Changshu Inst Technol, Sch Chem & Mat Engn, Changshu 215500, Jiangsu, Peoples R China.^[Zhang, Shuwen] Univ South China, Nucl Resources Engn Coll, Hengyang 421001, Hunan, Peoples R China.^[Huang, Tao] Chongqing Univ, State Key Lab Coal Mine Disaster Dynam & Control, Chongqing 400044, Peoples R China.^[Huang, Tao] Chongqing Univ, Sch Resource & Environm Sci, Chongqing 400044, Peoples R China.
关键词：
Municipal solid waste incineration fly ash;Heavy metals;pH control;Electrokinetic remediation;Enhancement
摘要：
The high leachability of heavy metals and toxic organic components has severely discouraged the broader resource recycling of municipal solid waste incineration fly ashes. In this study, a recycling system combining water washing treatment, cationic buffer solution recovery, and electrokinetic remediation was designed based on pH controls and comprehensively explored in terms of strengthening the removal of heavy metals from samples and reducing the risk of environmental leaching of heavy metals in fly ashes. The water washing pretreatment removed a considerable amount of soluble minerals from the fly ash and lowered the initial pH of the electrochemical system to below 10. The dosing of buffer cations decreased the thickness of the diffuse double layer and ameliorated the mobility of the heavy metal species in the pore fluid. Cu was most sensitive to the changes in the operating factors during electrokinetics. The effects of the remediation times and voltage gradients were more significant on heavy metal removal than those of the nitric acid concentration in the electrokinetic optimization system. The leaching toxicities of zinc, lead, copper, and cadmium were reduced by 82.59%, 73.64%, 67.07%, and 93.13%, respectively. Generally, the recovery of the water washing leachate not only enhanced the performance of the electrokinetic remediation for the municipal solid waste incineration fly ash but also avoided downstream disposal of the effluent.
摘要：
This study was intended to determine the variation rules of the radon emanation coefficient in dump-leached uranium tailing sand. A temperature and humidity controllable device for measuring the emanation coefficient was designed. Tailing sand with different grain sizes was selected from uranium tailings in southern China. An orthogonal experimental design was conducted to determine the radon emanation coefficient of the sand under different temperatures, humidities and grain sizes. Experimental results showed that the air temperature, humidity and grain size have significant effects on the emanation coefficient. The variation rules regarding the radon emanation coefficient showed significant reference value.
作者：
Wen, Lei*;Luo, Zhou Quan;Yang, Shi Jiao;Qin, Ya Guang;Ma, Shao Wei;...
期刊：
ROYAL SOCIETY OPEN SCIENCE,2019年6(3):181591 ISSN：2054-5703
通讯作者：
Wen, Lei
作者机构：
[Wen, Lei; Luo, Zhou Quan; Ma, Shao Wei; Jiang, Hong; Qin, Ya Guang] Cent S Univ, Sch Resources & Safety Engn, Changsha 410083, Hunan, Peoples R China.;[Yang, Shi Jiao] Univ South China, Sch Nucl Resources Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Wen, Lei] C;Cent S Univ, Sch Resources & Safety Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
P-wave velocity;damage index;integrality coefficient;point load strength;rock mass
摘要：
The damage index is a crucial controlling parameter for rock mass strength and deformation in civil, geological and mining engineering projects. In this study, a new method was proposed for computing the damage index of a rock mass based on the field point load strength. This method provides a strength ratio whose numerator is the point load strength (PLS) of splitting along the pre-existing joint and whose denominator is the PLS of intact rock failure. To validate this method, the authors derived a relationship between the damage index and the integrality coefficient using an empirical relation. Moreover, numerous experimental tests were conducted, including P-wave testing and on-site point load testing. Finally, linear regression analysis was performed to analyse the correlation between the new damage index D R and the integrality coefficient K V . This study demonstrates that the presented new method is sensitive to both plasticity and damage in estimating the damage degree of rock masses in underground excavation and tunnel engineering.
关键词：
Adsorption;Hexametaphosphate green rust;Hexavalent chromium removal;Intercalated anion;Layered double hydroxides
摘要：
Hexametaphosphate intercalated green rust (hexa-P GR) was fabricated by a coprecipitation process in an anaerobic environment to improve the adsorption of hexa-P GR for Cr(VI) and the total Cr under various aqueous conditions. Three kinetic models including the pseudo-first-order, intraparticle, and Elovich were appropriate in describing the adsorption of hexa-P GR towards Cr(VI) and the total Cr. The maximum mono-layer adsorption capacities (mg/g) of hexa-P GR for Cr(VI) at pH of 2 and 7 were 87.64 and 92.25, respectively, with the theoretical maximum capacity (mg/g) of 52.73 being obtained at pH of 7. Some competing cations existing in solutions such as Al(3+), Ca(2+), and Mg(2+) would consume more hexa-P GR to remove Cr species. The neutral and weak alkaline environment was conducive to the hexa-P GR reuse, while the strong alkaline environment was beneficial to the removal of the total Cr. The orthogonal variables including the initial pH, the flow rate, and the Cr(VI) concentration all significantly influenced Cr removal. The sequences of reaction pathways referring to the adsorption of hexa-P GR differently occurred in various pH conditions.
作者机构：
[Dai, Zhongran; Sun, Yusu; Zhang, Hui; Ding, Dexin; Li, Le] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China
通讯机构：
[Ding, Dexin] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.
会议名称：
4th North American Symposium on Chemical Reaction Engineering (NASCRE)
会议时间：
MAR, 2019
会议地点：
Houston, TX
摘要：
Efficient removal of U(VT) from mine radioactive wastewater is important for environmental remediation and radiation protection. In this work, a new series of polyamidoxime/polydopamine-decorated graphene oxide (GO/PDA/PAO) composites were obtained by one-pot synthesis and used for the removal of U(VI) from mine radioactive wastewater. The as-synthesized GO/PDA/PAO composites (GO/PDA/PAO-0.2, GO/PDA/PAO-0.5, and GO/PDA/PAO-1) were examined by transmission electron microscopy, Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS). The effects of pH, ionic strength, contact time, initial U(VI) concentration, and temperature on the adsorption behavior of U(VI) by GO/PDA/PAO were investigated. The maximum adsorption capacity of GO/PDA/PAO-0.2 was 502.5 m g/g at pH 6.0 and 298 K. The adsorption kinetics and isotherms can be well illustrated by the pseudo-second-order kinetics model and Langmuir isotherm model. The thermodynamic study indicated that the removal of U(VI) by GO/PDA/PAO-0.2 was an endothermic and spontaneous process. The interactions between GO/PDA/PAO-0.2 and U(VI) were explained based on the FT-IR and XPS analyses. Furthermore, GO/PDA/PAO was applied for U(VI) removal from mine radioactive wastewater. The concentration of U(Vl) in the wastewater can be reduced to 7.28 /mu g/L, which is below the allowable uranium concentration for drinking water stipulated in the standard by the World Health Organization (30 mu g/L).
