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Chen J.,Shaanxi Normal University | Chai L.,Changan University | Chai L.,Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education | Zhao H.,Shaanxi Normal University | And 2 more authors.
Fluoride | Year: 2016

Chronic exposure to high fluoride ion levels (F) may lead to local tissue disturbances, known as fluorosis. The present study was conducted to determine the effects of sodium fluoride (NaF) on the growth, metamorphosis, and skeletal development in tadpoles of Rana chensinesis and Rana nigromaculata. The mortality, percentage of tadpoles completing metamorphosis, total length, body weight, and hindlimb length were determined. In addition, skeletal systems were investigated by using double staining methodology at Gosner stages 36, 42, and 46. The results showed that chronic exposure to 50 mg NaF/L significantly increased the mortality, inhibited metamorphosis, and delayed development in R. chensinesis and R. nigromaculata tadpoles. The NaF treatment also produced flexural tail malformations in R. chensinesis tadpoles but not in R. nigromaculata tadpoles, stimulated bone mineralization in R. chensinesis tadpoles, and retarded the deposition of calcium in R. nigromaculata tadpoles. In conclusion, our study suggests that fluoride may affect skeletal ossification differently in different frog species due to differences in sensitivity or the duration of the exposure. © 2016 The International Society for Fluoride Research Inc.

Gong Y.,Beijing University of Technology | Gong Y.,Ohio State University | Zhang Y.,Beijing University of Technology | Lan S.,Beijing University of Technology | And 2 more authors.
Water Resources Management | Year: 2016

Accurate and reliable prediction of groundwater level is essential for water resource development and management. This study was carried out to test the validity of three nonlinear time-series intelligence models, artificial neural networks (ANN), support vector machines (SVM) and adaptive neuro fuzzy inference system (ANFIS) in the prediction of the groundwater level when taking the interaction between surface water and groundwater into consideration. These three models were developed and applied for two wells near Lake Okeechobee in Florida, United States. 10 years data-sets including hydrological parameters such as precipitation (P), temperature (T), past groundwater level (G) and lake level (L) were used as input data to forecast groundwater level. Five quantitative standard statistical performance evaluation measures, correlation coefficient (R), normalized mean square error (NMSE), root mean squared error (RMSE), Nash-Sutcliffe efficiency coefficient (NS) and Akaike information criteria (AIC), were employed to evaluate the performances of these models. The conclusions achieved from this research would be beneficial to the water resources management, it proved the necessity and effect of considering the surface water-groundwater interaction in the prediction of groundwater level. These three models were proved applicable to the prediction of groundwater level one, two and three months ahead for the area that is close to the surface water, for example, the lake area. The models using P, T, G and L achieved better prediction result than that using P, T and G only. At the same time, results from ANFIS and SVM models were more accurate than that from ANN model. © 2015, Springer Science+Business Media Dordrecht.

Wang Y.L.,Changan University | Wang Y.L.,Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education
Applied Mechanics and Materials | Year: 2014

The dynamic adsorption of atmospheric trace Kr and Xe, which discharged from the dynamic adsorption experimental equipment at room temperature, on selected adsorbents VACF and GCAC were studied. The stable isotope 84Kr and 129Xe were designated as tracing indicator and determined by ICP-MS. The results suggest that: (1)under the experimental conditions, which included that the column length was 1m, the flow was 2m3/h, and the maximum uniform loading density of VACF column and GCAC column was respectively 0.0165 g/cm3and 0.459 g/cm3, the DACwhich indicated the adsorption capacity of Kr and Xe adsorbed on VACF at room temperature was about 3.08×104 cm3/g, the DAC which indicated the adsorption capacity of Kr and Xe adsorbed on GCAC at room temperature was about 5.55×103 cm3/g; (2) the air flow capacity couldn’t be promoted by simply increasing the column length of VACF or GCAC. For VACF adsorbent, although its DACwas superior to the GCAC’s, but when the length of VACF column was increased to 2m, the air flow resistance was ascended obviously, and the air flow capacity was descended substantially. However, because the cost-effectiveness of GCAC adsorbent was higher, the flow resistance of GCAC column was smaller and the controlling range of air flow was larger than VACF, all of these results show that the comprehensive performance of GCAC is better than VACF at present. © (2014) Trans Tech Publications, Switzerland.

Wang C.,Shaanxi Normal University | Liang G.,Shaanxi Normal University | Chai L.,Changan University | Chai L.,Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education | Wang H.,Shaanxi Normal University
Aquatic Toxicology | Year: 2016

Chinese toad (Bufo gargarizans) tadpoles were exposed to copper (1, 6.4, 32 and 64μgL-1 copper) from the beginning of larval period through completion of metamorphosis. We examined the effects of chronic copper exposure on mortality, growth, time to metamorphosis, tail resorption time, body size at the metamorphic climax (Gs 42) and completion of metamorphosis (Gs 46) and thyroid gland histology. In addition, type 2 and 3 iodothyronine deiodinase (Dio2 and Dio3), thyroid hormone receptors (TRα and TRβ) mRNA levels were also measured to assess disruption of TH synthesis. Our result showed that 6.4-64μgL-1 copper concentration increased the mortality and inhibited the growth of B. gargarizans tadpoles. In addition, significant reduction in size at Gs 42 and a time delay to Gs 42 were observed at 6.4-64μgL-1 copper treatments. Moreover, histological examinations have clearly revealed that 64μgL-1 copper caused follicular cell hyperplasia in thyroid gland. According to real-time PCR results, exposure to 32 and 64μgL-1 copper significantly up-regulated mRNA expression of Dio3, but down-regulated mRNA expression of TRα and TRβ mRNA level. We concluded that copper delayed amphibian metamorphosis through changing mRNA expression of Dio3, TRα and TRβ, which suggests that copper might have the endocrine-disrupting effect. © 2015 Elsevier B.V.

Zhang H.,Changan University | Zhang H.,Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education | Lan T.,Changan University | Wang B.,Changan University | And 2 more authors.
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2016

The potential changes are occurring in the Earth's water cycle due to climate change and human activities, which cause water supply system mainly affected by hydrological processes are extremely complex and variable. Water resources management based on water demand has been not an accurate reflection to the regional water resources status. It needs us develop water resources management from the perspective of water cycle. This study introduces the basic theory and method of water resources management based on evapotranspiration (ET) control, and put forward the ET-based model on county-territory scale and its calculation method. The ET-based model is different from the traditional method, origins from regional water cycle process and stresses the natural attributes of water resources. In addition, this study considers Luannan County with over-pumping groundwater and further discusses the case study about water resource allocation based on ET. The research shows the ET-based model chooses ET control as the means, cutting ET as the goal, physical drive processes of water resources as theoretical basis, and takes into account many practical problems related with county development such as the industrial development, planting structure, water-saving potential and excessive exploitation of water resources. The treatment can make the planning scheme from the model is accord with the actuality of regional development and give controlling the over-pumping exploitation of water resources more maneuverable. © 2016, China Water Power Press. All right reserved.

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