The policy of linkage of urban construction land increase with rural construction land decrease is an important task for poverty alleviation. It not only promotes the intensive use of land and the coordinated developm...The policy of linkage of urban construction land increase with rural construction land decrease is an important task for poverty alleviation. It not only promotes the intensive use of land and the coordinated development of urban and rural areas,but also plays an essential role in poverty alleviation development and the relocation of poverty alleviation. It provides a strong guarantee for winning the project of poverty alleviation. Taking the project of linkage of urban construction land increase with rural construction land decrease in Binchuan County in Yunnan Province,combined with the current situation of poverty alleviation and relocation in Binchuan County,the implementation of related policies of linkage of urban construction land increase with rural construction land decrease,and path of relocation poverty alleviation,this paper introduced problems in the implementation of policies of linkage of urban construction land increase with rural construction land decrease in Binchuan County,and came up with recommendations for the project of poverty alleviation through linkage of urban construction land increase with rural construction land decrease.展开更多
With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, name...With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, namely reclamation of rural construction land, fund raising and management of connection turnover index, based on the comprehensive analysis of political connotation in increase and decrease of urban and rural construction land. The modes include "village relocation and combination", "hollow village" reconstruction, high-rise stereo, village relocation in the mountain and related capital raising and turnover index management and the applicable regions of various modes are analyzed and studied. The research result provides reference for the reasonable operation of increase and decrease link of urban and rural construction land.展开更多
In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogene...In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogeneous chemistry(AHC),and their combined impact(ALL)on the variations in O_(3)and PM_(2.5)during the 2014–2020 in eastern China.Our analysis confirmed that ARI curtailed O_(3)while elevating PM_(2.5).AHC reduced O_(3)through heterogeneous absorption of NOx and hydroxideswhile notably fostering fine-grained sulfate,resulting in a PM_(2.5)increase.Emission reductions mitigated the inhibitory impact of ARI on meteorological fields and photolysis rates.Emission reduction individually without aerosol feedback led to a 5.43 ppb O_(3)increase and a 22.89μg/m^(3)PM_(2.5)decrease.ARI and AHC amplified the emission-reduction-induced(ERI)O_(3)rise by 1.83 and 0.31 ppb,respectively.The response of ARI to emission diminution brought about a modest PM_(2.5)increase of 0.31μg/m^(3).Conversely,AHC,acting as the primary contributor,caused a noteworthy PM_(2.5)decrease of 4.60μg/m^(3).As efforts concentrate on reducing PM_(2.5),the promotion of ARI on PM_(2.5)counterbalanced the efficacy of emission reduction and the AHC-induced strengthening of PM_(2.5)decrease.The ALL magnified the ERI O_(3)increase by 38.9%and PM_(2.5)decrease by 18.7%.Sensitivity experiments with different degrees of emission reduction demonstrated a consistent linear relationship between the ALL-induced enhancement of O_(3)increase and PM_(2.5)decrease to the ERI PM_(2.5)decline.Our investigation revealed the complex connection between emissions and aerosol feedback in influencing air quality.展开更多
Considering the factors affecting the increasing rate of power consumption, the BP neural network structure and the neural network forecasting model of the increasing rate of power consumption were established. Immune...Considering the factors affecting the increasing rate of power consumption, the BP neural network structure and the neural network forecasting model of the increasing rate of power consumption were established. Immune genetic algorithm was applied to optimizing the weight from input layer to hidden layer, from hidden layer to output layer, and the threshold value of neuron nodes in hidden and output layers. Finally, training the related data of the increasing rate of power consumption from 1980 to 2000 in China, a nonlinear network model between the increasing rate of power consumption and influencing factors was obtained. The model was adopted to forecasting the increasing rate of power consumption from 2001 to 2005, and the average absolute error ratio of forecasting results is 13.521 8%. Compared with the ordinary neural network optimized by genetic algorithm, the results show that this method has better forecasting accuracy and stability for forecasting the increasing rate of power consumption.展开更多
Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO 2 s...Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO 2 since the beginning of the 20th century, identifying a strengthening linkage, such that in recent decades the rate of sea-ice decrease mirrors the increase in CO 2 , with r ～ -0.95 over the last four decades, thereby indicating that 90% (r 2 ～ 0.90) of the decreasing sea-ice extent is empirically "accounted for" by the increasing CO 2 in the atmosphere. The author presents an empirical relation between annual sea-ice extent and global atmospheric CO 2 concentrations, in which sea-ice reductions are linearly, inversely proportional to the magnitude of increase of CO 2 over the last few decades. This approximates sea-ice changes during the most recent four decades, with a proportionality constant of 0.030 million km 2 per ppmv CO 2 . When applied to future emission scenarios of the Intergovernmental Panel on Climate Change (IPCC), this relationship results in substantially faster ice decreases up to 2050 than predicted by IPCC models. However, departures from this projection may arise from non-linear feedback effects and/or temporary natural variations on interannual timescales, such as the record minimum of sea-ice extent observed in September 2007.展开更多
Recently,an article was published on solid effect(SE)dynamic nuclear polarization(DNP)enhancement,where the au-thors reported achieving 1H enhancement factors up to 500 by increasing the microwave power at 9.4 T,marki...Recently,an article was published on solid effect(SE)dynamic nuclear polarization(DNP)enhancement,where the au-thors reported achieving 1H enhancement factors up to 500 by increasing the microwave power at 9.4 T,marking the highest SE enhancement to date[1].展开更多
HVDC auxiliary power control can significantly improve the transient stability of AC/DC power grid.An HVDC adaptive emergency power support method based on unbalanced power on line estimation is proposed in this paper...HVDC auxiliary power control can significantly improve the transient stability of AC/DC power grid.An HVDC adaptive emergency power support method based on unbalanced power on line estimation is proposed in this paper.By establishing the extended state equation of the system,the on line dynamic estimation of unbalanced power of the system was realized.On this basis,power support was realized based on the principle of the ladder increment.The optimal DC was selected by the power support factor,and the emergency power support controller was installed on the DC.This emergency power support method can realize dynamic optimal power support with minimized control cost.The three infeed HVDC system was built on PSCAD.The simulation results show the effectiveness of the proposed method.展开更多
There is a danger of power generation efficiency decreasing due to voltage increase when clustered residential PV systems are grid-interconnected to a single distribution line. As a countermeasure, installation of the...There is a danger of power generation efficiency decreasing due to voltage increase when clustered residential PV systems are grid-interconnected to a single distribution line. As a countermeasure, installation of the reactive power control of an inverter at each residence has been considered. However, there are not many types of inverters that can operate reactive power control because there are insufficient effects on a low voltage distribution line with low penetration PV with reactive power control. Therefore, it is necessary to consider how to increase generation efficiency with a lower number of inverters. In this paper, four Japanese standard distribution line structures, for example of a residential area on ＂C1＂, where 2,160 residential PV systems are grid-interconnected, are selected. The optimal setting of reactive power control at each residence is computed on the distribution lines with a greedy method.展开更多
Reactive power control can control voltage within the proper range from the power network side or from the distribution generation （PV （photovoltaic）） side. Reactive power control from the power network side is si...Reactive power control can control voltage within the proper range from the power network side or from the distribution generation （PV （photovoltaic）） side. Reactive power control from the power network side is simpler because little controlled object apparatus, such as STATCOM, is required. However, it is difficult to optimize the individual voltages of residential consumers because few data have been obtained by the power network side as compared with the power generation side. Energy loss at each residence with PV is different due to the difference in the grid-interconnection condition, such as distribution line impedance when the same operating voltage is set at all residences. Therefore, in this paper, the authors propose an advanced reactive power control method for residential PV systems in order to optimally control the voltage at individual residences so as to minimize energy loss fluctuation. The effectiveness of the proposed reactive power control is demonstrated by numerical simulation.展开更多
基金Supported by the Project of Poverty Alleviation Office of People’s Government of Dali Bai Autonomous Prefecture
文摘The policy of linkage of urban construction land increase with rural construction land decrease is an important task for poverty alleviation. It not only promotes the intensive use of land and the coordinated development of urban and rural areas,but also plays an essential role in poverty alleviation development and the relocation of poverty alleviation. It provides a strong guarantee for winning the project of poverty alleviation. Taking the project of linkage of urban construction land increase with rural construction land decrease in Binchuan County in Yunnan Province,combined with the current situation of poverty alleviation and relocation in Binchuan County,the implementation of related policies of linkage of urban construction land increase with rural construction land decrease,and path of relocation poverty alleviation,this paper introduced problems in the implementation of policies of linkage of urban construction land increase with rural construction land decrease in Binchuan County,and came up with recommendations for the project of poverty alleviation through linkage of urban construction land increase with rural construction land decrease.
文摘With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, namely reclamation of rural construction land, fund raising and management of connection turnover index, based on the comprehensive analysis of political connotation in increase and decrease of urban and rural construction land. The modes include "village relocation and combination", "hollow village" reconstruction, high-rise stereo, village relocation in the mountain and related capital raising and turnover index management and the applicable regions of various modes are analyzed and studied. The research result provides reference for the reasonable operation of increase and decrease link of urban and rural construction land.
基金supported by the National Natural Science Foundation of China(No.42077192)the National Key Basic Research&Development Program of China(No.2020YFA0607802).
文摘In the context of the prevalent winter air quality issues in China marked by declining PM_(2.5)and rising O_(3),this study employed amodified WRF-Chem model to examine the aerosol radiation interaction(ARI),heterogeneous chemistry(AHC),and their combined impact(ALL)on the variations in O_(3)and PM_(2.5)during the 2014–2020 in eastern China.Our analysis confirmed that ARI curtailed O_(3)while elevating PM_(2.5).AHC reduced O_(3)through heterogeneous absorption of NOx and hydroxideswhile notably fostering fine-grained sulfate,resulting in a PM_(2.5)increase.Emission reductions mitigated the inhibitory impact of ARI on meteorological fields and photolysis rates.Emission reduction individually without aerosol feedback led to a 5.43 ppb O_(3)increase and a 22.89μg/m^(3)PM_(2.5)decrease.ARI and AHC amplified the emission-reduction-induced(ERI)O_(3)rise by 1.83 and 0.31 ppb,respectively.The response of ARI to emission diminution brought about a modest PM_(2.5)increase of 0.31μg/m^(3).Conversely,AHC,acting as the primary contributor,caused a noteworthy PM_(2.5)decrease of 4.60μg/m^(3).As efforts concentrate on reducing PM_(2.5),the promotion of ARI on PM_(2.5)counterbalanced the efficacy of emission reduction and the AHC-induced strengthening of PM_(2.5)decrease.The ALL magnified the ERI O_(3)increase by 38.9%and PM_(2.5)decrease by 18.7%.Sensitivity experiments with different degrees of emission reduction demonstrated a consistent linear relationship between the ALL-induced enhancement of O_(3)increase and PM_(2.5)decrease to the ERI PM_(2.5)decline.Our investigation revealed the complex connection between emissions and aerosol feedback in influencing air quality.
基金Project(70373017) supported by the National Natural Science Foundation of China
文摘Considering the factors affecting the increasing rate of power consumption, the BP neural network structure and the neural network forecasting model of the increasing rate of power consumption were established. Immune genetic algorithm was applied to optimizing the weight from input layer to hidden layer, from hidden layer to output layer, and the threshold value of neuron nodes in hidden and output layers. Finally, training the related data of the increasing rate of power consumption from 1980 to 2000 in China, a nonlinear network model between the increasing rate of power consumption and influencing factors was obtained. The model was adopted to forecasting the increasing rate of power consumption from 2001 to 2005, and the average absolute error ratio of forecasting results is 13.521 8%. Compared with the ordinary neural network optimized by genetic algorithm, the results show that this method has better forecasting accuracy and stability for forecasting the increasing rate of power consumption.
基金supported by the Mohn-Sverdrup Center for Global Ocean StudiesOperational Oceanography at the Nansen Center and the Research Council of Norway+1 种基金is a contribution to the International Polar Year―Climate of the Arcticits Role for Europe (IPY-CARE) project, headed by the author
文摘Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO 2 since the beginning of the 20th century, identifying a strengthening linkage, such that in recent decades the rate of sea-ice decrease mirrors the increase in CO 2 , with r ～ -0.95 over the last four decades, thereby indicating that 90% (r 2 ～ 0.90) of the decreasing sea-ice extent is empirically "accounted for" by the increasing CO 2 in the atmosphere. The author presents an empirical relation between annual sea-ice extent and global atmospheric CO 2 concentrations, in which sea-ice reductions are linearly, inversely proportional to the magnitude of increase of CO 2 over the last few decades. This approximates sea-ice changes during the most recent four decades, with a proportionality constant of 0.030 million km 2 per ppmv CO 2 . When applied to future emission scenarios of the Intergovernmental Panel on Climate Change (IPCC), this relationship results in substantially faster ice decreases up to 2050 than predicted by IPCC models. However, departures from this projection may arise from non-linear feedback effects and/or temporary natural variations on interannual timescales, such as the record minimum of sea-ice extent observed in September 2007.
文摘Recently,an article was published on solid effect(SE)dynamic nuclear polarization(DNP)enhancement,where the au-thors reported achieving 1H enhancement factors up to 500 by increasing the microwave power at 9.4 T,marking the highest SE enhancement to date[1].
基金the National Natural Science Foundation of China(Grant No.51607158)the Key Scientific Technological Project in Henan Province(Grant No.192102210075)。
文摘HVDC auxiliary power control can significantly improve the transient stability of AC/DC power grid.An HVDC adaptive emergency power support method based on unbalanced power on line estimation is proposed in this paper.By establishing the extended state equation of the system,the on line dynamic estimation of unbalanced power of the system was realized.On this basis,power support was realized based on the principle of the ladder increment.The optimal DC was selected by the power support factor,and the emergency power support controller was installed on the DC.This emergency power support method can realize dynamic optimal power support with minimized control cost.The three infeed HVDC system was built on PSCAD.The simulation results show the effectiveness of the proposed method.
文摘There is a danger of power generation efficiency decreasing due to voltage increase when clustered residential PV systems are grid-interconnected to a single distribution line. As a countermeasure, installation of the reactive power control of an inverter at each residence has been considered. However, there are not many types of inverters that can operate reactive power control because there are insufficient effects on a low voltage distribution line with low penetration PV with reactive power control. Therefore, it is necessary to consider how to increase generation efficiency with a lower number of inverters. In this paper, four Japanese standard distribution line structures, for example of a residential area on ＂C1＂, where 2,160 residential PV systems are grid-interconnected, are selected. The optimal setting of reactive power control at each residence is computed on the distribution lines with a greedy method.
文摘Reactive power control can control voltage within the proper range from the power network side or from the distribution generation （PV （photovoltaic）） side. Reactive power control from the power network side is simpler because little controlled object apparatus, such as STATCOM, is required. However, it is difficult to optimize the individual voltages of residential consumers because few data have been obtained by the power network side as compared with the power generation side. Energy loss at each residence with PV is different due to the difference in the grid-interconnection condition, such as distribution line impedance when the same operating voltage is set at all residences. Therefore, in this paper, the authors propose an advanced reactive power control method for residential PV systems in order to optimally control the voltage at individual residences so as to minimize energy loss fluctuation. The effectiveness of the proposed reactive power control is demonstrated by numerical simulation.
