Dissolved organic matter(DOM)in rivers plays a key role in the global carbon cycle and aquatic ecosystems,yet its spatiotemporal dynamics across complex terrains remains inadequately characterized.To address this gap,...Dissolved organic matter(DOM)in rivers plays a key role in the global carbon cycle and aquatic ecosystems,yet its spatiotemporal dynamics across complex terrains remains inadequately characterized.To address this gap,we conducted seasonal sampling along the Luan River and examined how DOM composition varies over space and time in response to environmental drivers.Using parallel factor analysis(PARAFAC),we identified two humic-like components(C1+C2,Em>380 nm)and one protein-like component(C3,Em<380 nm).DOM fluorescence intensity was lowest in winter,while C1 and C3 levels peaked in autumn and C2 in summer(p<0.05).Spatially,C1 and C3 levels were highest downstream regions,whereas C2 peaked in the midstream section(p<0.05).Microbial sources dominated DOM in spring,winter,and in both headwater and downstream areas(FI>1.9).Principal coordinates analysis(PCoA)combined with multi-response permutation process(MRPP)confirmed significant spatiotemporal differences in DOM composition(p<0.05).Random forest modeling showed humic-like components were more sensitive to environmental changes.Redundancy analysis(RDA)and Mantel tests identified temperature as the dominant seasonal driver of DOM variation(p<0.05),while dissolved total phosphorus(DTP)and nitrate nitrogen(NO_(3)^(-)-N)were the key spatial determinants.Significant correlations were also observed between NO_(3)^(-)-N and ammonium nitrogen(NH_(4)^(+)-N),as well as between DTP and DOM,suggesting shared origins and compositional linkages(p<0.05).Our findings highlight the pronounced seasonal and spatial heterogeneity of DOM in multi-terrain river systems,offering valuable insights into carbon dynamics and ecosystem functioning in river systems.展开更多
An internal transport barrier(ITB)can be formed on EAST in exploring high-parameter operation.Previous studies show that safety factor(q)profiles,Shafranov shift and magnetohydrodynamic behaviors could be helpful in I...An internal transport barrier(ITB)can be formed on EAST in exploring high-parameter operation.Previous studies show that safety factor(q)profiles,Shafranov shift and magnetohydrodynamic behaviors could be helpful in ITB formation by suppressing anomalous transport.Recently,electron density evolution with high resolution demonstrates that fishbone could be dominant in electron density ITB formation and sustainment.The power threshold is low in the fishbone condition and the electron density profile is determined by traits of fishbone.Simulation shows that the low-k ion mode is suppressed by fishbone.Direct measurement of turbulence in the inner region shows that the internal kink mode could sustain an electron temperature ITB by suppressing the trapped electron mode.The multi-scale interaction between the kink mode and turbulence by current could be key in sustaining high-electron-temperature long-pulse operation.展开更多
A discharge with electron temperature up to 14 keV has been achieved in EAST.Analysis of the electron cyclotron current drive(ECCD)efficiency at high electron temperature under EAST parameters is presented using C3PO/...A discharge with electron temperature up to 14 keV has been achieved in EAST.Analysis of the electron cyclotron current drive(ECCD)efficiency at high electron temperature under EAST parameters is presented using C3PO/LUKE code.Simulation results show that the ECCD efficiency of X-mode increases with central electron temperature up to 10 keV and then starts to decrease above 10 keV,at a specific magnetic field and toroidal angle.The efficiency degradation is due to the presence of the third harmonic extraordinary(X3)downshifted absorption at the low field side(LFS);even the cold resonance of X3 mode is located outside the plasma.As the electron temperature increases from 5 to 20 ke V,the X3 absorption increases from 0.9%to 96.4%.The trapping electron effect at the LFS produces a reverse Ohkawa current.The competition between the Fisch–Boozer current drive and the Ohkawa current drive results in a decrease in ECCD efficiency.ECCD efficiency optimization is achieved through two methods.One is to increase the toroidal angle,leading to X2 mode predominating again over X3 mode and the electron resonance domain of X2 mode moving far from the trapped/passing boundary.The second one is to increase the magnetic field to move away the X3 resonance layer from the plasma,hence less EC power absorbed by X3 mode.展开更多
In this paper, the efficient population utilization strategy for particle swarm optimization (EPUSPSO) is proposed to solve the economic load dispatch (ELD) problem of power system. This algorithm improves the accurac...In this paper, the efficient population utilization strategy for particle swarm optimization (EPUSPSO) is proposed to solve the economic load dispatch (ELD) problem of power system. This algorithm improves the accuracy and the speed of its convergence by changing the number of particles effectively, and improving the velocity equation and position equation. In order to verify the effectiveness of the algorithm, this algorithm is tested in three different ELD cases of power system include IEEE 3-unit case, 13-unit case, and 40-unit case, and the obtained results are compared with those obtained from other algorithms using the same system parameters. The compared results show that the algorithm can find the optimal solution effectively and accurately, and avoid falling into the local optimal problem;meanwhile, faster speed can be ensured in the case.展开更多
A new versatile optimization, the particle swarm optimization based on multi-agent system (MAPSO) is presented. The economic load dispatch (ELD) problem of power system can be solved by the algorithm. By competing and...A new versatile optimization, the particle swarm optimization based on multi-agent system (MAPSO) is presented. The economic load dispatch (ELD) problem of power system can be solved by the algorithm. By competing and cooperating with the randomly selected neighbors, and adjusting its global searching ability and local exploring ability, this algorithm achieves the goal of high convergence precision and speed. To verify the effectiveness of the proposed algorithm, this algorithm is tested by three different ELD cases, including 3, 13 and 40 units IEEE cases, and the experiment results are compared with those tested by other intelligent algorithms in the same cases. The compared results show that feasible solutions can be reached effectively, local optima can be avoided and faster solution can be applied with the proposed algorithm, the algorithm for ELD problem is versatile and efficient.展开更多
基金Basic Research Project of Universities in Hebei Province,Affiliated with Shijiazhuang City,Grant/Award Number:241791187ANatural Science Foundation of Hebei Province,Grant/Award Number:E2024208033+1 种基金Hebei Province graduate student innovation ability training program,Grant/Award Number:CXZZSS2025068Hebei Provincial Key Research Projects,Grant/Award Number:21373904D。
文摘Dissolved organic matter(DOM)in rivers plays a key role in the global carbon cycle and aquatic ecosystems,yet its spatiotemporal dynamics across complex terrains remains inadequately characterized.To address this gap,we conducted seasonal sampling along the Luan River and examined how DOM composition varies over space and time in response to environmental drivers.Using parallel factor analysis(PARAFAC),we identified two humic-like components(C1+C2,Em>380 nm)and one protein-like component(C3,Em<380 nm).DOM fluorescence intensity was lowest in winter,while C1 and C3 levels peaked in autumn and C2 in summer(p<0.05).Spatially,C1 and C3 levels were highest downstream regions,whereas C2 peaked in the midstream section(p<0.05).Microbial sources dominated DOM in spring,winter,and in both headwater and downstream areas(FI>1.9).Principal coordinates analysis(PCoA)combined with multi-response permutation process(MRPP)confirmed significant spatiotemporal differences in DOM composition(p<0.05).Random forest modeling showed humic-like components were more sensitive to environmental changes.Redundancy analysis(RDA)and Mantel tests identified temperature as the dominant seasonal driver of DOM variation(p<0.05),while dissolved total phosphorus(DTP)and nitrate nitrogen(NO_(3)^(-)-N)were the key spatial determinants.Significant correlations were also observed between NO_(3)^(-)-N and ammonium nitrogen(NH_(4)^(+)-N),as well as between DTP and DOM,suggesting shared origins and compositional linkages(p<0.05).Our findings highlight the pronounced seasonal and spatial heterogeneity of DOM in multi-terrain river systems,offering valuable insights into carbon dynamics and ecosystem functioning in river systems.
基金supported by the National Key R&D Program of China(No.2017YFE0301705)supported in part by the Key Program of Research and Development of Hefei Science Center,CAS(No.2019HSC-KPRD001)+1 种基金supported by National Natural Science Foundation of China(Nos.11975271 and 11675211)partly supported by the Collaborative Research Program of the Research Institute for Applied Mechanics,Kyushu University。
文摘An internal transport barrier(ITB)can be formed on EAST in exploring high-parameter operation.Previous studies show that safety factor(q)profiles,Shafranov shift and magnetohydrodynamic behaviors could be helpful in ITB formation by suppressing anomalous transport.Recently,electron density evolution with high resolution demonstrates that fishbone could be dominant in electron density ITB formation and sustainment.The power threshold is low in the fishbone condition and the electron density profile is determined by traits of fishbone.Simulation shows that the low-k ion mode is suppressed by fishbone.Direct measurement of turbulence in the inner region shows that the internal kink mode could sustain an electron temperature ITB by suppressing the trapped electron mode.The multi-scale interaction between the kink mode and turbulence by current could be key in sustaining high-electron-temperature long-pulse operation.
基金the National Key R&D Program of China(Nos.2017YFE0300500 and 2017YFE0300503)the Comprehensive Research Facility for Fusion Technology Program of China(No.2018-000052-73-01-001228).
文摘A discharge with electron temperature up to 14 keV has been achieved in EAST.Analysis of the electron cyclotron current drive(ECCD)efficiency at high electron temperature under EAST parameters is presented using C3PO/LUKE code.Simulation results show that the ECCD efficiency of X-mode increases with central electron temperature up to 10 keV and then starts to decrease above 10 keV,at a specific magnetic field and toroidal angle.The efficiency degradation is due to the presence of the third harmonic extraordinary(X3)downshifted absorption at the low field side(LFS);even the cold resonance of X3 mode is located outside the plasma.As the electron temperature increases from 5 to 20 ke V,the X3 absorption increases from 0.9%to 96.4%.The trapping electron effect at the LFS produces a reverse Ohkawa current.The competition between the Fisch–Boozer current drive and the Ohkawa current drive results in a decrease in ECCD efficiency.ECCD efficiency optimization is achieved through two methods.One is to increase the toroidal angle,leading to X2 mode predominating again over X3 mode and the electron resonance domain of X2 mode moving far from the trapped/passing boundary.The second one is to increase the magnetic field to move away the X3 resonance layer from the plasma,hence less EC power absorbed by X3 mode.
文摘In this paper, the efficient population utilization strategy for particle swarm optimization (EPUSPSO) is proposed to solve the economic load dispatch (ELD) problem of power system. This algorithm improves the accuracy and the speed of its convergence by changing the number of particles effectively, and improving the velocity equation and position equation. In order to verify the effectiveness of the algorithm, this algorithm is tested in three different ELD cases of power system include IEEE 3-unit case, 13-unit case, and 40-unit case, and the obtained results are compared with those obtained from other algorithms using the same system parameters. The compared results show that the algorithm can find the optimal solution effectively and accurately, and avoid falling into the local optimal problem;meanwhile, faster speed can be ensured in the case.
文摘A new versatile optimization, the particle swarm optimization based on multi-agent system (MAPSO) is presented. The economic load dispatch (ELD) problem of power system can be solved by the algorithm. By competing and cooperating with the randomly selected neighbors, and adjusting its global searching ability and local exploring ability, this algorithm achieves the goal of high convergence precision and speed. To verify the effectiveness of the proposed algorithm, this algorithm is tested by three different ELD cases, including 3, 13 and 40 units IEEE cases, and the experiment results are compared with those tested by other intelligent algorithms in the same cases. The compared results show that feasible solutions can be reached effectively, local optima can be avoided and faster solution can be applied with the proposed algorithm, the algorithm for ELD problem is versatile and efficient.
