In order to simulate changes in the water quality of the Miyun Reservoir dueto continuous descent of surface water level, a 3-D ecological hydrodynamic model was developedthrough coupling the water quality analysis si...In order to simulate changes in the water quality of the Miyun Reservoir dueto continuous descent of surface water level, a 3-D ecological hydrodynamic model was developedthrough coupling the water quality analysis simulation program (WASP) with the environmental fluiddynamics code (EFDC). The model was then calibrated and verified. Four scenarios (S1, S21, S22 andS23) were simulated using the model. Results show that the water quality of the Miyun Reservoirunder conditions of low surface water level is apparently affected by different amounts of inflowand different total phosphorus (TP) loadings. The chlorophyll-a concentration might exceed 10 μg/Lin many areas of the Miyun Reservoir (This limitative value is seen as a critical value ofeutrophication) when large loadings of TP enter due to the amount of inflow increasing. Results ofscenario S23 indicate that control of TP loadings can decrease chlorophyll-a concentrationeffectively, and the water quality of the Miyun Reservoir will improve or retain its status quo.展开更多
It is to conduct the teaching exploration for the situational sports model＇s implementation in sports teaching. It is indicated that the implementation of the situational teaching is good to improve the students＇ in...It is to conduct the teaching exploration for the situational sports model＇s implementation in sports teaching. It is indicated that the implementation of the situational teaching is good to improve the students＇ initiative and interest for study; good for the students＇ participation; good to improve students＇ initiative, sports ability and sports level; good to promote students to have healthy physical and psychological development; good to optimize the teaching process and activate the class atmosphere; and also good to promote students＇ social development factor. It is an ideal teaching concept and teaching model.展开更多
Over the last 45 years, the development of backbone telecommunications systems and construction of strategic oil and gas pipelines has spanned tens of thousands ofkilometres in harsh environments （arctic to tropical,...Over the last 45 years, the development of backbone telecommunications systems and construction of strategic oil and gas pipelines has spanned tens of thousands ofkilometres in harsh environments （arctic to tropical, unmanned or developing areas）. As the vast majority of these areas are without an electrical power lines infrastructure, the need arose for a highly reliable and maintenance-free power supply to allow the continuous operations of these projects. ORC （Organic Rankine Cycle） based on CCVT （closed cycle vapor turbogenerator） was specially developed for the special requirements. The paper presents the CCVT and its mode of operation, design criteria and case studies in projects implemented in the last 45 years.展开更多
Under the conditions of climate warming,grassland degradation,frequent sandstorms,and fast increases in livestock numbers,coordinating animal husbandry and ecological protection is an important issue facing Mongolia.U...Under the conditions of climate warming,grassland degradation,frequent sandstorms,and fast increases in livestock numbers,coordinating animal husbandry and ecological protection is an important issue facing Mongolia.Using Khutag-Undur as an example,this study explores the dynamic process,future scenarios,and optimization strategies of the animal husbandry system in a typical Soum of Mongolia from 2015 to 2050 under three future climate socioeconomic scenarios of CMIP 6:SSP1-RCP2.6,SSP2-RCP4.5,and SSP5-RCP8.5.First,the animal husbandry system was deconstructed into three subsystems:grassland primary production,livestock secondary production,and herder consumption.Based on the negative feedback mechanism of forage-livestock balance,a system dynamics model for the Khutag-Undur Soum animal husbandry system was developed.This model integrates spatial data such as land cover and NPP,as well as statistical data on livestock,herder income and expenditures,sample plot surveys,and herder questionnaires.The model was used to simulate the historical changes(2015-2022)in forage production and carrying capacity,livestock stock,and livestock output of Khutag-Undur,and then to forecast the future scenarios of those variables for 2022-2050.Second,the most suitable future scenario for the Soum was identified by comparing the three future scenarios using a pastural system sustainability evaluation method.Finally,based on three indicators of livestock numbers,a two-step livestock reduction strategy was proposed.The main conclusions are that the rapid growth of livestock numbers in Khutag-Undur places considerable pressure on the grassland,and the SSP1-RCP2.6 scenario is the most suitable future scenario for the Soum.However,even in this suitable scenario,grassland overloading remains evident.The continuous implementation of a livestock reduction strategy is recommended to maintain the sustainable development of animal husbandry and grassland conservation.展开更多
The timing dynamics of regulating negative emotion with expressive suppression and cognitive reappraisal were investigated in a Chinese sample. Event-Related Potentials were recorded while subjects were required to vi...The timing dynamics of regulating negative emotion with expressive suppression and cognitive reappraisal were investigated in a Chinese sample. Event-Related Potentials were recorded while subjects were required to view, suppress emotion expression to, or reappraise emotional pictures. The results showed a similar reduction in self-reported negative emotion during both strategies. Additionally, expressive suppression elicited larger amplitudes than reappraisal in central-frontal P3 component(340–480 ms). More importantly, the Late Positive Potential(LPP) amplitudes were decreased in each 200 ms of the 800–1600 ms time intervals during suppression vs. viewing conditions. In contrast, LPP amplitudes were similar for reappraisal and viewing conditions in all the time windows, except for the decreased amplitudes during reappraisal in the 1400–1600 ms. The LPP(but not P3) amplitudes were positively related to negative mood ratings, whereas the amplitudes of P3, rather than LPP, predict self-reported expressive suppression. These results suggest that expressive suppression decreases emotion responding more rapidly than reappraisal, at the cost of greater cognitive resource involvements in Chinese individuals.展开更多
In this paper, to better understand the impact of awareness and the network structure on epidemic transmission, we divide the population into four subpopulations corresponding to different physical states and consciou...In this paper, to better understand the impact of awareness and the network structure on epidemic transmission, we divide the population into four subpopulations corresponding to different physical states and conscious states, and we first propose a modified disease- awareness model, then verify the global stability of the disease-free and endemic equilib- ria, and finally present numerical simulations to demonstrate the theoretical analysis. By examining the spreading influences of model parameters, we find that the outbreak scale can be effectively controlled through increasing the spread rate of awareness or reducing the rate of awareness loss. That is to say, all sorts of media publicity are meaningful. Meanwhile, we find that infection will be affected by consciousness through the control variable.展开更多
文摘In order to simulate changes in the water quality of the Miyun Reservoir dueto continuous descent of surface water level, a 3-D ecological hydrodynamic model was developedthrough coupling the water quality analysis simulation program (WASP) with the environmental fluiddynamics code (EFDC). The model was then calibrated and verified. Four scenarios (S1, S21, S22 andS23) were simulated using the model. Results show that the water quality of the Miyun Reservoirunder conditions of low surface water level is apparently affected by different amounts of inflowand different total phosphorus (TP) loadings. The chlorophyll-a concentration might exceed 10 μg/Lin many areas of the Miyun Reservoir (This limitative value is seen as a critical value ofeutrophication) when large loadings of TP enter due to the amount of inflow increasing. Results ofscenario S23 indicate that control of TP loadings can decrease chlorophyll-a concentrationeffectively, and the water quality of the Miyun Reservoir will improve or retain its status quo.
文摘It is to conduct the teaching exploration for the situational sports model＇s implementation in sports teaching. It is indicated that the implementation of the situational teaching is good to improve the students＇ initiative and interest for study; good for the students＇ participation; good to improve students＇ initiative, sports ability and sports level; good to promote students to have healthy physical and psychological development; good to optimize the teaching process and activate the class atmosphere; and also good to promote students＇ social development factor. It is an ideal teaching concept and teaching model.
文摘Over the last 45 years, the development of backbone telecommunications systems and construction of strategic oil and gas pipelines has spanned tens of thousands ofkilometres in harsh environments （arctic to tropical, unmanned or developing areas）. As the vast majority of these areas are without an electrical power lines infrastructure, the need arose for a highly reliable and maintenance-free power supply to allow the continuous operations of these projects. ORC （Organic Rankine Cycle） based on CCVT （closed cycle vapor turbogenerator） was specially developed for the special requirements. The paper presents the CCVT and its mode of operation, design criteria and case studies in projects implemented in the last 45 years.
基金The National Key R&D Program of China(2022YFE0119200)The National Natural Science Foundation of China(32161143025,42371283)The Second Tibetan Plateau Scientific Expedition and Research Program(STEP),China(2019QZKK0603)。
文摘Under the conditions of climate warming,grassland degradation,frequent sandstorms,and fast increases in livestock numbers,coordinating animal husbandry and ecological protection is an important issue facing Mongolia.Using Khutag-Undur as an example,this study explores the dynamic process,future scenarios,and optimization strategies of the animal husbandry system in a typical Soum of Mongolia from 2015 to 2050 under three future climate socioeconomic scenarios of CMIP 6:SSP1-RCP2.6,SSP2-RCP4.5,and SSP5-RCP8.5.First,the animal husbandry system was deconstructed into three subsystems:grassland primary production,livestock secondary production,and herder consumption.Based on the negative feedback mechanism of forage-livestock balance,a system dynamics model for the Khutag-Undur Soum animal husbandry system was developed.This model integrates spatial data such as land cover and NPP,as well as statistical data on livestock,herder income and expenditures,sample plot surveys,and herder questionnaires.The model was used to simulate the historical changes(2015-2022)in forage production and carrying capacity,livestock stock,and livestock output of Khutag-Undur,and then to forecast the future scenarios of those variables for 2022-2050.Second,the most suitable future scenario for the Soum was identified by comparing the three future scenarios using a pastural system sustainability evaluation method.Finally,based on three indicators of livestock numbers,a two-step livestock reduction strategy was proposed.The main conclusions are that the rapid growth of livestock numbers in Khutag-Undur places considerable pressure on the grassland,and the SSP1-RCP2.6 scenario is the most suitable future scenario for the Soum.However,even in this suitable scenario,grassland overloading remains evident.The continuous implementation of a livestock reduction strategy is recommended to maintain the sustainable development of animal husbandry and grassland conservation.
基金supported by National Natural Science Foundation of China(NSFC3117098931371042)+1 种基金the Keygrant Project of Chinese Ministry of Education(NO.311032)the Special Grant for Postdoctoral Research in Chongqing(Xm2014059)
文摘The timing dynamics of regulating negative emotion with expressive suppression and cognitive reappraisal were investigated in a Chinese sample. Event-Related Potentials were recorded while subjects were required to view, suppress emotion expression to, or reappraise emotional pictures. The results showed a similar reduction in self-reported negative emotion during both strategies. Additionally, expressive suppression elicited larger amplitudes than reappraisal in central-frontal P3 component(340–480 ms). More importantly, the Late Positive Potential(LPP) amplitudes were decreased in each 200 ms of the 800–1600 ms time intervals during suppression vs. viewing conditions. In contrast, LPP amplitudes were similar for reappraisal and viewing conditions in all the time windows, except for the decreased amplitudes during reappraisal in the 1400–1600 ms. The LPP(but not P3) amplitudes were positively related to negative mood ratings, whereas the amplitudes of P3, rather than LPP, predict self-reported expressive suppression. These results suggest that expressive suppression decreases emotion responding more rapidly than reappraisal, at the cost of greater cognitive resource involvements in Chinese individuals.
文摘In this paper, to better understand the impact of awareness and the network structure on epidemic transmission, we divide the population into four subpopulations corresponding to different physical states and conscious states, and we first propose a modified disease- awareness model, then verify the global stability of the disease-free and endemic equilib- ria, and finally present numerical simulations to demonstrate the theoretical analysis. By examining the spreading influences of model parameters, we find that the outbreak scale can be effectively controlled through increasing the spread rate of awareness or reducing the rate of awareness loss. That is to say, all sorts of media publicity are meaningful. Meanwhile, we find that infection will be affected by consciousness through the control variable.
