The DFI-1 submarine pipeline was investigated using a dual-frequency side-scan sonar and a swath sounder system. More than a hundred scour pits under the pipeline were found, most of which have caused the span of the ...The DFI-1 submarine pipeline was investigated using a dual-frequency side-scan sonar and a swath sounder system. More than a hundred scour pits under the pipeline were found, most of which have caused the span of the pipeline to increase and threatened its safety. The maximum allowable free span length （MAFSL） of the pipeline was determined through the limitations re- garding maximum allowable stress under static or quasi-static loads and the onset of Vortex Induced Vibrations （VIV） under different hydrodynamic actions. The results show that the MAFSL under static conditions is 56m. However, the MAFSLs are 30m and 20m under ordinary weather conditions and hurricane-induced currents for the 100-year return period, respectively, to avoid VIV as cal- culated by using the highest safety class factor. It is suggested that spanning pipelines longer than 20 m should be supported. Addi- tionally, eight successive spans which may also threaten the pipeline were proposed. The most hazardous scour pits are along the pipeline section from KP42 to KP51.展开更多
The state support of the agriculture is increasing with the globalization of Russia, the need to shape level and instruments in accordance with the WTO requirements. For Russia, rational state support of agriculture i...The state support of the agriculture is increasing with the globalization of Russia, the need to shape level and instruments in accordance with the WTO requirements. For Russia, rational state support of agriculture is topical according to the domestic economic problems： insufficient financing in Russia, in the regions; degradation of production facilities; turnover acreage reduction; reduction in livestock; and according to the external economic factors： the accession to the WTO, the transition to the Common Economic Space, and subsequently, the Eurasian Economic Union, global change conditions in the global food market, an increase in the world population, increasing demand for food resources, a significant increase in food prices on world markets, the increased activity of Russian agricultural producers in the world markets of grain products; ensuring of economic stability systems, critical analysis of the tools and the effectiveness of economic policy. According to the IMF, the economic has slowed down despite the state support for agriculture should stay a priority in the government＇s economic policy, in the regions.展开更多
With the rapid growth of the offshore wind industry, the innovative floating offshore wind turbine is chosen as the most feasible device to harvest the vast wind energy in deep water area. However there is no practica...With the rapid growth of the offshore wind industry, the innovative floating offshore wind turbine is chosen as the most feasible device to harvest the vast wind energy in deep water area. However there is no practical design guide for the floating wind turbine especially the floating foundation. In this paper, based on the investigation on the worldwide floating wind turbine and current available expertise on floating platforms accumulated in offshore O/G （oil and gas） industry, an integrated design methodology is presented according to the specialized characteristics of wind turbine, including the type selection of foundation and mooring system, design standard, design procedure, design conditions, key technologies involved. Finally a semi-submersible floating foundation is designed to support certain megawatt-rating wind turbine of Goldwind and also performance analysis and code checks are performed to validate the design. The design method of the floating foundation provided in this paper is proved feasible and can be adopted in practical engineering design.展开更多
The interlayer space of the layered materials is not always the electrochemical active area for contributing to the pseudocapacitive process. To our knowledge, few efforts have been devoted to investigating the effect...The interlayer space of the layered materials is not always the electrochemical active area for contributing to the pseudocapacitive process. To our knowledge, few efforts have been devoted to investigating the effect of interlayer distance of layered double hydroxides（LDHs） on pseudocapacitors. Here, we obtained the CoAl-LDH with different interlayer distance via the reaction in aqueous media hydrothermally. Electrochemical characterization reveals that the CoAl（DS^-（dodecyl sulfate））-LDHs with an interlayer distance of 2.58 nm can deliver higher specific capacitance of 1481.7 F g^-1 than CoAl（SO4^2-）-LDH（0.87 nm, 1252.7 F g^-1） and CoAl（CO3^2-）-LDH（0.76 nm, 1149.2 Fg^-1） at a discharge current density of 1 A g^-1. An asymmetric supercapacitor with the CoAl（DS^-）-LDHs‖activated carbon also shows a better electrochemical performance, including a high energy density of54.2 W h kg^-1 at a power density of 0.9 kW kg^-1 and a longterm stability, in comparison with CoAl（SO4^2-）-LDH and CoAl（CO3^2-）-LDH ‖activated carbon.展开更多
基金supported by the National Basic Research Program of China (973 Program) (Grant No.2005CB422304)the Ocean University of China Scientific Research Start-up Funds Project for Introduced Talents
文摘The DFI-1 submarine pipeline was investigated using a dual-frequency side-scan sonar and a swath sounder system. More than a hundred scour pits under the pipeline were found, most of which have caused the span of the pipeline to increase and threatened its safety. The maximum allowable free span length （MAFSL） of the pipeline was determined through the limitations re- garding maximum allowable stress under static or quasi-static loads and the onset of Vortex Induced Vibrations （VIV） under different hydrodynamic actions. The results show that the MAFSL under static conditions is 56m. However, the MAFSLs are 30m and 20m under ordinary weather conditions and hurricane-induced currents for the 100-year return period, respectively, to avoid VIV as cal- culated by using the highest safety class factor. It is suggested that spanning pipelines longer than 20 m should be supported. Addi- tionally, eight successive spans which may also threaten the pipeline were proposed. The most hazardous scour pits are along the pipeline section from KP42 to KP51.
文摘The state support of the agriculture is increasing with the globalization of Russia, the need to shape level and instruments in accordance with the WTO requirements. For Russia, rational state support of agriculture is topical according to the domestic economic problems： insufficient financing in Russia, in the regions; degradation of production facilities; turnover acreage reduction; reduction in livestock; and according to the external economic factors： the accession to the WTO, the transition to the Common Economic Space, and subsequently, the Eurasian Economic Union, global change conditions in the global food market, an increase in the world population, increasing demand for food resources, a significant increase in food prices on world markets, the increased activity of Russian agricultural producers in the world markets of grain products; ensuring of economic stability systems, critical analysis of the tools and the effectiveness of economic policy. According to the IMF, the economic has slowed down despite the state support for agriculture should stay a priority in the government＇s economic policy, in the regions.
文摘With the rapid growth of the offshore wind industry, the innovative floating offshore wind turbine is chosen as the most feasible device to harvest the vast wind energy in deep water area. However there is no practical design guide for the floating wind turbine especially the floating foundation. In this paper, based on the investigation on the worldwide floating wind turbine and current available expertise on floating platforms accumulated in offshore O/G （oil and gas） industry, an integrated design methodology is presented according to the specialized characteristics of wind turbine, including the type selection of foundation and mooring system, design standard, design procedure, design conditions, key technologies involved. Finally a semi-submersible floating foundation is designed to support certain megawatt-rating wind turbine of Goldwind and also performance analysis and code checks are performed to validate the design. The design method of the floating foundation provided in this paper is proved feasible and can be adopted in practical engineering design.
基金financially supported by the National Natural Science Foundation of China (21501152,21571159,21671178,21441003,51521091 and 51525206)China Postdoctoral Science Foundation (2017M611282)+5 种基金Program for Changjiang Scholars and Innovative Research Team in University (IRT15R61)Ministry of Science and Technology of China (2016YFA0200100 and 2016YBF0100100)Foundation of Zhengzhou University of Light Industry (2014BSJJ054)Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09010104)Projects for Public Entrepreneurship and Public Innovation of ZZULI (2017ZCKJ215)Key Program of Henan Province for Science and Technology (162102210212)
文摘The interlayer space of the layered materials is not always the electrochemical active area for contributing to the pseudocapacitive process. To our knowledge, few efforts have been devoted to investigating the effect of interlayer distance of layered double hydroxides（LDHs） on pseudocapacitors. Here, we obtained the CoAl-LDH with different interlayer distance via the reaction in aqueous media hydrothermally. Electrochemical characterization reveals that the CoAl（DS^-（dodecyl sulfate））-LDHs with an interlayer distance of 2.58 nm can deliver higher specific capacitance of 1481.7 F g^-1 than CoAl（SO4^2-）-LDH（0.87 nm, 1252.7 F g^-1） and CoAl（CO3^2-）-LDH（0.76 nm, 1149.2 Fg^-1） at a discharge current density of 1 A g^-1. An asymmetric supercapacitor with the CoAl（DS^-）-LDHs‖activated carbon also shows a better electrochemical performance, including a high energy density of54.2 W h kg^-1 at a power density of 0.9 kW kg^-1 and a longterm stability, in comparison with CoAl（SO4^2-）-LDH and CoAl（CO3^2-）-LDH ‖activated carbon.
