283 research outputs found

    Beneficial synergy of adsorption-intercalation-conversion mechanisms in Nb<sub>2</sub>O<sub>5</sub>@nitrogen-doped carbon frameworks for promoted removal of metal ionsviahybrid capacitive deionization

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    Capacitive deionization (CDI) is an emerging water purification technology, but the ion adsorption capacity of traditional carbon-based CDI electrodes is still unsatisfactory. Herein, a novel faradaic electrode by anchoring Nb2O5nanoparticles on nitrogen-doped carbon frameworks as anodes and activated carbon (AC) as cathodes in a hybrid capacitive deionization (HCDI) system was originally developed to capture Na+ionsviaadsorption-intercalation-conversion mechanisms. The synergistic effects of the nanostructure and carbon coating were beneficial to enhancing electrical conductivity and offering fast Na+ion diffusion pathways. Impressively, the HCDI system demonstrated an excellent ion adsorption capacity of 35.4 mg g−1in a 500 mg L−1NaCl solution at 1.2 V as well as stable regeneration ability.In situRaman andex situXPS measurements unraveled that the mechanism of ion removal from water was the reversible redox reaction of Nb2O5. The new overall understanding of the synergistic effects opens opportunities for the design of HCDI systems for efficient removal of metal ions from saline water.</p

    Submarine groundwater discharge in Dongshan Bay, China: A master regulator of nutrients in spring and potential national significance of small bays

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    Despite over 90% of China’s coastal bays have an area less than 500 km2, the geochemical effects of SGD on those ecosystems are ambiguous. Based on mapping and time-series observations of Ra isotopes and nutrients, a case study of small bays (&lt;500 km2), we revealed that submarine groundwater discharge (SGD) predominately regulated the distribution of nutrients and fueled algal growth in Dongshan Bay, China. On the bay-wide scale, the SGD rate was estimated to be 0.048 ± 0.022 m day−1 and contributed over 95% of the nutrients. At the time-series site where the bay-wide highest Ra activities in the bottom water marked an SGD hotspot with an average rate an order of magnitude greater, the maximum chlorophyll concentration co-occurred, suggesting that SGD may support the algal bloom. The ever-most significant positive correlations between 228Ra and nutrients throughout the water column (P&lt; 0.01, R2 &gt; 0.90 except for soluble reactive phosphorus in the surface) suggested the predominance of SGD in controlling nutrient distribution in the bay. Extrapolated to a national scale, the SGD-carried dissolved inorganic nitrogen flux in small bays was twice as much as those in large bays (&gt;2,000 km2). Thus, the SGD-carried nutrients in small bays merit immediate attention in environmental monitoring and management

    Experimental Research on Scour Protection Range and Protection Effect of Large Diameter Monopile Foundation

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    [Introduction] Under the wave-current combinations during the service period of offshore wind turbine, local scour inevitably occurs around pile foundation, which threatens the overall stability and safety of offshore wind turbine. [Method] In this paper, the normal physical model test at a scale of 1∶30 was carried out for the wind power foundation with a diameter of 8.0 m to study the scour depth, sand cover, solidified soil protection range, and protection effect. [Result] The results show that due to the good hydrodynamic conditions considered in this test, the maximum scour depth is 0.133 cm. In this case, the 1 cm-thick sand cover with a splicing size of 1.0 m×1.0 m can meet the stability requirements. When solidified soil is adopted for protection, the protection range shall not be less than 5 times the pile diameter, and block stones shall be laid at the edge of solidified soil to avoid scouring at the lower part of solidified soil. [Conclusion] The test results can provide reference for scouring test and engineering design of similar projects

    Transgenic Potato with Resistant to PVX,PVY and PSTVd Simultaneously by amiRNA-mediated and Resistance Evaluation

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    peer reviewedIn order to obtain potato plants which could be resistant to multiple viruses ( viroid) simultaneous- ly,P25,HC-Pro,and Virp1 gene targeting PVX,PVY,and PSTVd proteins were cloned,respectively. Three types of amiRNAs targeting sequences encoding the silencing suppressor P25,HC-Pro and Virp1 were designed by using Ar- abidopsis thaliana miR159a as backbone. These three amiRNA sequences were connected by Overlapping PCR. The synthetic of P25,HC-Pro and Virp1 gene was inserted into the expression vector pCAMBIA1300-221 to form p1300-221-preamiR-P25-HCPro-Virp1,and the vector was verified by PCR and restriction enzyme digestion. Pre-a- miR-P25-HCPro-Virp1 was transformed into minituber of potato cultivar Favorita by Agrobacterium tumefaciens in- fection. 15 transformed plants were obtained through regenerating,pressure screening and differentiation. PCR re- sults showed that 10 of them were detected the same size fragment ( 729 bp) as the target gene. Further qRT-PCR t e s t i n g c o n f i r m e d t h a t a m i R - P 2 5 - H C P r o - V i r p 1 g e n e w a s e x p r e s s e d i n 1 0 t r a n s f o r m e d p l a n t s ,a n d t h e r e l a t i v e e x p r e s - sion was between 7. 68 - 21. 37. Inoculated the T0 transgenic plants with the mixture virus of PVX,PVY and PSTVd by friction into the leaves of the plants at the 6 - 8 leaf stage. The plant growth was observed after 20 days and the results showed that the control plants were severely susceptible,with symptoms such as short plants and mottled leaves,while the transformed plants did not show infection symptoms,and growth normally. There was no vi- rus detected by RT-PCR either. This indicated that the transfected amiR-P25-HCPro-Virp could be stably expressed in the transformed plants,and the transformed plants were resistant to PVX,PVY and PVSTd viruses ( viroid) . Transformed plants resistant to PVX,PVY and PVSTd were obtained,and the resistance was significant,which pro- vided new genetic resources for potato virus-resistant breeding

    A hybrid CNN-LSTM model for predicting PM2.5 in Beijing based on spatiotemporal correlation

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    Long-term exposure to air environments full of suspended particles, especially PM2.5, would seriously damage people's health and life (i.e., respiratory diseases and lung cancers). Therefore, accurate PM2.5 prediction is important for the government authorities to take preventive measures. In this paper, the advantages of convolutional neural networks (CNN) and long short-term memory networks (LSTM) models are combined. Then a hybrid CNN-LSTM model is proposed to predict the daily PM2.5 concentration in Beijing based on spatiotemporal correlation. Specifically, a Pearson's correlation coefficient is adopted to measure the relationship between PM2.5 in Beijing and air pollutants in its surrounding cities. In the hybrid CNN-LSTM model, the CNN model is used to learn spatial features, while the LSTM model is used to extract the temporal information. In order to evaluate the proposed model, three evaluation indexes are introduced, including root mean square error, mean absolute percent error, and R-squared. As a result, the hybrid CNN-LSTM model achieves the best performance compared with the Multilayer perceptron model (MLP) and LSTM. Moreover, the prediction accuracy of the proposed model considering spatiotemporal correlation outperforms the same model without spatiotemporal correlation. Therefore, the hybrid CNN-LSTM model can be adopted for PM2.5 concentration prediction
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