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.
