摘要 :
Nitrification inhibitors (NI) are widely used in fertilization to modify nitrogen (N) transformation in soil for matching crop N requirement and reducing N loss to environments. However, the effects of major NI products in China o...
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Nitrification inhibitors (NI) are widely used in fertilization to modify nitrogen (N) transformation in soil for matching crop N requirement and reducing N loss to environments. However, the effects of major NI products in China on inorganic N transformation in purple soil are poorly quantified. Therefore, incubation experiment was carried out to study the effects of major NI products including Entrench (En), 3,4-dimethylpyrazole phosphate (DMPP) and dicyandiamide (DCD) on inorganic N transformation in typical purple soil which is the predominant soil in Sichuan Basin, China. With the same incubation condition (soil moisture: 70% of water hold capacity at 25℃), the contents of ammonium nitrogen (NH_4~+-N), nitrite nitrogen (NO_3~--N), and pH value were measured, and then the apparent nitrification rate and inhibitory rate of the three nitrification inhibitors were calculated. Results showed that the NI can significantly reduce the acidification rate of the purple soil. And a strong nitrification process was showed in the soil without nitrification inhibitors (CK), with 81.4% of NH_4~+-N disappearing from the mineral nitrogen pool during the whole incubation period of 100 days. Compared with CK treatment, addition of NI products resulted in a reduced disappearance of NH_4~+-N by 9.8% for En, 24.6% for DMPP and 26.1% for DCD, respectively. The nitrification process of nitrogen in soil was obviously inhibited by NI products, with the inhibition rate of 7.1% to 95.8% for DMPP and of 3.8% to 97.2% for DCD, respectively. Thus, the nitrification process was delayed by up to 30 days for these two treatments. The inhibition effect of nitrification process by En product was less than that of DMPP and DCD. Under the recommendation rate of NI products, the nitrification inhibition rates were in the order of DCD (5% w/w)>DMPP (1% w/w)>En (2.4% w/w). We concluded that all the major NI products in China could significantly inhibit the process of nitrification in purple soil. While, DMPP and DCD are superior to En product in maintaining NH_4~+-N, inhibiting nitrification process and reducing acidification of the purple soil.
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摘要 :
For components in equipment that are used in the littoral with a high requirement for corrosion resistance, the design project of electroless plated nickel-phosphorus complex deposit was put forward in the paper. The treating proc...
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For components in equipment that are used in the littoral with a high requirement for corrosion resistance, the design project of electroless plated nickel-phosphorus complex deposit was put forward in the paper. The treating process of chromate sealing and organic porosity sealing for the surface of the deposit was optimized. By applying two different types of electroless plating solution, a double layer electroless plating deposit with 120mV of stable potential difference was prepared. The design of complex deposit can efficiently reduce porosity and improve the corrosion resistance of the deposit. Through X-ray diffractometer (XRD) and scanning electron microscope (SEM), the phase structure, constituent and chemical form were analyzed, which settled the foundation for the application of amorphous state Ni-P alloy on equipment.
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摘要 :
For components in equipment that are used in the littoral with a high requirement for corrosion resistance, the design project of electroless plated nickel-phosphorus complex deposit was put forward in the paper. The treating proc...
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For components in equipment that are used in the littoral with a high requirement for corrosion resistance, the design project of electroless plated nickel-phosphorus complex deposit was put forward in the paper. The treating process of chromate sealing and organic porosity sealing for the surface of the deposit was optimized. By applying two different types of electroless plating solution, a double layer electroless plating deposit with 120mV of stable potential difference was prepared. The design of complex deposit can efficiently reduce porosity and improve the corrosion resistance of the deposit. Through X-ray diffractometer (XRD) and scanning electron microscope (SEM), the phase structure, constituent and chemical form were analyzed, which settled the foundation for the application of amorphous state Ni-P alloy on equipment.
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摘要 :
For components in equipment that are used in the littoral with a high requirement for corrosion resistance, the design project of electroless plated nickel-phosphorus complex deposit was put forward in the paper. The treating proc...
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For components in equipment that are used in the littoral with a high requirement for corrosion resistance, the design project of electroless plated nickel-phosphorus complex deposit was put forward in the paper. The treating process of chromate sealing and organic porosity sealing for the surface of the deposit was optimized. By applying two different types of electroless plating solution, a double layer electroless plating deposit with 120mV of stable potential difference was prepared. The design of complex deposit can efficiently reduce porosity and improve the corrosion resistance of the deposit. Through X-ray diffractometer (XRD) and scanning electron microscope (SEM), the phase structure, constituent and chemical form were analyzed, which settled the foundation for the application of amorphous state Ni-P alloy on equipment.
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摘要 :
Purple soil is one of important agricultural soils in China. However, widespread soil acidification and soil fertility decline have limited the sustainable use of the purple soil in recent decades. Biochar, derived from agricultur...
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Purple soil is one of important agricultural soils in China. However, widespread soil acidification and soil fertility decline have limited the sustainable use of the purple soil in recent decades. Biochar, derived from agricultural waste such as rice husk, shows great potential for controlling soil acidification and fertility improvement of acidified soils. In this study, pot experiment was conducted to investigate the impact of rice-husk biochar application on soil properties and wheat yield on an acidified purple soil. The results showed that soil pH under treatments of 0.5%, 1%, 2% and 5% biochar application was respectively increased by 0.2, 0.4, 0.5 and 1.2 units than that of the treatment without biochar application. Conversely, soil available iron content after biochar application was significantly reduced by 23.6%, 41.5%, 65.4% and 96.0%, respectively. Furthermore, biochar applications increased soil available phosphorus content by up to 115 mg/kg from 20 mg/kg under treatment without biochar application. The improved soil properties after biochar application resulted in significantly higher grain yield of wheat (Triticum aestivum. L. Varieties Chuanmai45 and Mianyang31). Compared with the control, wheat yield with treatments of 0.5%, 1%, 2% and 5% biochar application was increased by 3.81%, 7.71%, 45.61% and 57.15%, respectively. The response of wheat yield to biochar application was closely correlated with soil available phosphorus and iron content. We therefore concluded that biochar application could improve soil fertility by decreasing soil acidity and iron toxicity, and consequently increasing soil phosphorus availability. These integrated effects thus resulted in better growth and yield of wheat grown in acidified purple soil.
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We relate capital structure of software vs. manufacturing listed companies in China to a more detailed measurement of political connections than the literature and document two main empirical regularities. We find both the softwar...
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We relate capital structure of software vs. manufacturing listed companies in China to a more detailed measurement of political connections than the literature and document two main empirical regularities. We find both the software and manufacturing firms have the equity financing preference and the manufacturing firms even have more pronounced equity financing preference. This challenges the previous literature. Moreover, we find that that the political connections of the software firms facilitate the short-term debt financing, while those of the manufacturing firms promote equity and long-term debt financing.
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