Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a ...Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a flat seabed.Actually,however,the transmitter dipole source will be rotated,tilted and deviated from the survey profile due to ocean currents.And free-fall receivers may be also rotated to some arbitrary horizontal orientation and located on sloping seafloor.In this paper,we investigate the effects of uncertainties in the transmitter tilt,transmitter rotation and transmitter deviation from the survey profile as well as in the receiver's location and orientation on marine CSEM data.The model study shows that the uncertainties of all position and orientation parameters of both the transmitter and receivers can propagate into observed data uncertainties,but to a different extent.In interpreting marine data,field data uncertainties caused by the position and orientation uncertainties of both the transmitter and receivers need to be taken into account.展开更多
The conversion mechanism of Al-goethite under the action of different additives(lime or reductant for typical or reductive Bayer digestion)was investigated by thermodynamic calculation,XRD,and SEM-EDS.The results show...The conversion mechanism of Al-goethite under the action of different additives(lime or reductant for typical or reductive Bayer digestion)was investigated by thermodynamic calculation,XRD,and SEM-EDS.The results show that the formation of Fe-substituted hydrocalumite is crucial to converting Al-goethite to hematite during Bayer digestion by adding lime.However,the conversion proceeds more easily under the action of reductant due to the rapid formation of magnetite.Additionally,Bayer liquor composition significantly affects the product composition and also the conversion rate of Al-goethite.Compared to typical Bayer digestion with Al-goethite containing gibbsitic bauxite as raw material,the red mud yield of reductive Bayer digestion decreases from 39.02%to 31.19%,and the grade of TFe in red mud increases from 41.66%to 53.80%.展开更多
With the aim to apply the electric fish into practice to assist coal mine water disaster life detection and rescue work, based on the analysis on swing propulsion movements of tail fin, this paper integrates the elect...With the aim to apply the electric fish into practice to assist coal mine water disaster life detection and rescue work, based on the analysis on swing propulsion movements of tail fin, this paper integrates the electromagnet technology with tail fin drive system by analyzing how the fish swims with tail fin under the law of progression. The principle, structure, and drive signals of tail fin electromagnetic drive are researched, the enforced situation of fish under eIectromagnetic driving modes are analyzed, and the experimental plat-form of tail fin electromagnetic drive is established. The best distance between electro- magnet and armature, which can realize the swing of tail fin, was researched in the experiment under water. The robotic fish structure parameters of tail fin electromagnetic drive was finalized by theoretical analysis and experimental measurement.展开更多
The research deals with the physical mechanisms of molecular restructurings in horny layers caused by effect of constant magnetic field. The structure of dehydrated epidermis and changes in light dispersion in water s...The research deals with the physical mechanisms of molecular restructurings in horny layers caused by effect of constant magnetic field. The structure of dehydrated epidermis and changes in light dispersion in water solution of glucose as the main component of inter-desmosome bridges under influence of constant magnetic field have been experimentally studied. On the basis of the results obtained these bridges are assumed to play key role in disordering the horny layer under the action of constant magnetic field. This assumption agrees with the results of clinical research.展开更多
Water-soluble, nondialyzable Maillard polymers were prepared by reacting D-xylose with 15N-glycine (and/or glycine) at 68 ℃ and pH 8.0 at equimolar concentrations of 1, 0.5 and 0.1 mol L-1, respectively,for 13 days a...Water-soluble, nondialyzable Maillard polymers were prepared by reacting D-xylose with 15N-glycine (and/or glycine) at 68 ℃ and pH 8.0 at equimolar concentrations of 1, 0.5 and 0.1 mol L-1, respectively,for 13 days and partitioned into acid-insoluble (MHA) and acid-soluble (MFA) fractions. The nitrogen forms in these polymers were studied by using the 15N cross polarization-magic angle spinning nuclear magnetic resonance (CPMAS NMR) technique in combination with chemical methods. The 15N nuclear magnetic resonance (NMR) data showed that while the yield, especially the MHA/MFA ratio, varied considerably with the concentrations of the reactants, the nitrogen distribution patterns of these polymers were quite similar.From 65% to 70% of nitrogen in them was in the secondary amide and/or indole form with 24%~25% present as aliphatic and/or aromatic ammes and 5% to 11% as pyrrole and/or pyrrole-like nitrogen. More than half (50%~77%) of the N in these polymers were nonhydrolyzable. The role of Maillard reaction in the formation of nonhydrolyzable nitrogen in soil organic matter is discussed.展开更多
MHPPs （micro hydro power plants） have become prominent in hydropower plants as a solution to provide the energy demands of the grid. In this study, a new hybrid renewable energy based DC excitation system for synchr...MHPPs （micro hydro power plants） have become prominent in hydropower plants as a solution to provide the energy demands of the grid. In this study, a new hybrid renewable energy based DC excitation system for synchronous generator in the developed MHPP system is introduced. Proposed hybrid DC excitation system consists of solar ＆ hydrogen energy based power generating systems. Hybrid renewable energy based system is used for the excitation of the synchronous generator in the MHPP test system. The renewables are used as a secondary energy source to provide the excitation current to a synchronous generator that generates energy in MHPP. A PV （photovoltaic） array is used as the main source of excitation, and a FC （fuel cell） stack is used for DC excitation in the lack of sunshine. In the experimental setup, an electrical control card is developed, and a microcontroller is used to perform the proposed excitation system. All experimental results obtained from 5 kW rated power MHHP test system. Experimental results show that, the proposed method provides the continuous excitation current, and the operation of the synchronous generator is uninterrupted. The proposed method is also practical and easily implemented for MHPP systems.展开更多
In this paper,we prove the global well-posedness of the incompressible magneto-hydrodynamics(MHD)equations near a homogeneous equilibrium in the domain R^k×T^(d-k),d≥2,k≥1 by using the comparison principle and ...In this paper,we prove the global well-posedness of the incompressible magneto-hydrodynamics(MHD)equations near a homogeneous equilibrium in the domain R^k×T^(d-k),d≥2,k≥1 by using the comparison principle and constructing the comparison function.展开更多
基金funded by the National Natural Science Foundation of China (41130420)the State High-Tech Development Plan of China (2012AA09A20101)
文摘Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a flat seabed.Actually,however,the transmitter dipole source will be rotated,tilted and deviated from the survey profile due to ocean currents.And free-fall receivers may be also rotated to some arbitrary horizontal orientation and located on sloping seafloor.In this paper,we investigate the effects of uncertainties in the transmitter tilt,transmitter rotation and transmitter deviation from the survey profile as well as in the receiver's location and orientation on marine CSEM data.The model study shows that the uncertainties of all position and orientation parameters of both the transmitter and receivers can propagate into observed data uncertainties,but to a different extent.In interpreting marine data,field data uncertainties caused by the position and orientation uncertainties of both the transmitter and receivers need to be taken into account.
基金support provided by the National Natural Science Foundation of China(No.52104353)。
文摘The conversion mechanism of Al-goethite under the action of different additives(lime or reductant for typical or reductive Bayer digestion)was investigated by thermodynamic calculation,XRD,and SEM-EDS.The results show that the formation of Fe-substituted hydrocalumite is crucial to converting Al-goethite to hematite during Bayer digestion by adding lime.However,the conversion proceeds more easily under the action of reductant due to the rapid formation of magnetite.Additionally,Bayer liquor composition significantly affects the product composition and also the conversion rate of Al-goethite.Compared to typical Bayer digestion with Al-goethite containing gibbsitic bauxite as raw material,the red mud yield of reductive Bayer digestion decreases from 39.02%to 31.19%,and the grade of TFe in red mud increases from 41.66%to 53.80%.
文摘With the aim to apply the electric fish into practice to assist coal mine water disaster life detection and rescue work, based on the analysis on swing propulsion movements of tail fin, this paper integrates the electromagnet technology with tail fin drive system by analyzing how the fish swims with tail fin under the law of progression. The principle, structure, and drive signals of tail fin electromagnetic drive are researched, the enforced situation of fish under eIectromagnetic driving modes are analyzed, and the experimental plat-form of tail fin electromagnetic drive is established. The best distance between electro- magnet and armature, which can realize the swing of tail fin, was researched in the experiment under water. The robotic fish structure parameters of tail fin electromagnetic drive was finalized by theoretical analysis and experimental measurement.
文摘The research deals with the physical mechanisms of molecular restructurings in horny layers caused by effect of constant magnetic field. The structure of dehydrated epidermis and changes in light dispersion in water solution of glucose as the main component of inter-desmosome bridges under influence of constant magnetic field have been experimentally studied. On the basis of the results obtained these bridges are assumed to play key role in disordering the horny layer under the action of constant magnetic field. This assumption agrees with the results of clinical research.
文摘Water-soluble, nondialyzable Maillard polymers were prepared by reacting D-xylose with 15N-glycine (and/or glycine) at 68 ℃ and pH 8.0 at equimolar concentrations of 1, 0.5 and 0.1 mol L-1, respectively,for 13 days and partitioned into acid-insoluble (MHA) and acid-soluble (MFA) fractions. The nitrogen forms in these polymers were studied by using the 15N cross polarization-magic angle spinning nuclear magnetic resonance (CPMAS NMR) technique in combination with chemical methods. The 15N nuclear magnetic resonance (NMR) data showed that while the yield, especially the MHA/MFA ratio, varied considerably with the concentrations of the reactants, the nitrogen distribution patterns of these polymers were quite similar.From 65% to 70% of nitrogen in them was in the secondary amide and/or indole form with 24%~25% present as aliphatic and/or aromatic ammes and 5% to 11% as pyrrole and/or pyrrole-like nitrogen. More than half (50%~77%) of the N in these polymers were nonhydrolyzable. The role of Maillard reaction in the formation of nonhydrolyzable nitrogen in soil organic matter is discussed.
文摘MHPPs （micro hydro power plants） have become prominent in hydropower plants as a solution to provide the energy demands of the grid. In this study, a new hybrid renewable energy based DC excitation system for synchronous generator in the developed MHPP system is introduced. Proposed hybrid DC excitation system consists of solar ＆ hydrogen energy based power generating systems. Hybrid renewable energy based system is used for the excitation of the synchronous generator in the MHPP test system. The renewables are used as a secondary energy source to provide the excitation current to a synchronous generator that generates energy in MHPP. A PV （photovoltaic） array is used as the main source of excitation, and a FC （fuel cell） stack is used for DC excitation in the lack of sunshine. In the experimental setup, an electrical control card is developed, and a microcontroller is used to perform the proposed excitation system. All experimental results obtained from 5 kW rated power MHHP test system. Experimental results show that, the proposed method provides the continuous excitation current, and the operation of the synchronous generator is uninterrupted. The proposed method is also practical and easily implemented for MHPP systems.
基金supported by National Natural Science Foundation of China (Grant No.11425103)
文摘In this paper,we prove the global well-posedness of the incompressible magneto-hydrodynamics(MHD)equations near a homogeneous equilibrium in the domain R^k×T^(d-k),d≥2,k≥1 by using the comparison principle and constructing the comparison function.
