According to the data from Investigation Report of Land Use Change in China,The Land Resources Communique of China and Chronicle of Statistical Data for Five Decades of New China issued from Ministry of Land Resources...According to the data from Investigation Report of Land Use Change in China,The Land Resources Communique of China and Chronicle of Statistical Data for Five Decades of New China issued from Ministry of Land Resources,we select two indices:change of farmland quantity and policy of farmland protection.According to econometric theory,by using Eviewes 5.1 software,co-integration analysis,Granger causality test,impulse response and other analysis methods,we analyze the relationship between change of farmland quantity and policy of farmland protection in China since the reform and opening-up.The results show that there is long-term balanced relationship between change of farmland quantity and policy of farmland protection,and there is a certain mechanism restricting motion of variables between the two so as to make the two deviate from each other little and step towards balance in the long run;there is unilateral causality relationship between farmland change and policy of farmland protection,namely that the farmland change is the Granger cause of policy of farmland protection,while policy of farmland protection is not the Granger cause of farmland change;impulse response and variance decomposition indicate that farmland change plays the role of promoting policy of farmland protection continuously,and the role is strengthened along with prolonged lag period;the policy of farmland protection has strong inertia,because it is impacted by the former level of itself,and the policy of farmland protection plays insignificant role in promoting farmland quantity.Consequently,the important approach of solving problem of rapid decrease of farmland is to formulate long-term strategy,strengthen theoretical research of farmland protection and reinforce degree of formulation,implementation and surveillance of farmland protection policy.展开更多
As is already known, most of the plasma literature is occupied with the plasma instabilities and the inevitable plasma waves, which remain major obstacles to the thermonuclear fusion process. Many experimental data on...As is already known, most of the plasma literature is occupied with the plasma instabilities and the inevitable plasma waves, which remain major obstacles to the thermonuclear fusion process. Many experimental data on the plasma waves （growth or damping） and their accompanied theoretical interpretations have been published during the last five decades; lots of them have been identified and justified as well, some not yet. One of these is our previous research on plasma waves, which originated in the early 80＇s at the Plasma Physics Laboratory of the NCSR ＂Demokritos＂. As the wave rising is defined by the growth rate （or the damping on the extinguishment）, these important wavy quantities will be studied in detail in the present paper. Three examples are taken from our previous theoretical results, and the first observation reveals that the involved quantities are complicated enough to be studied by themselves. So, the use of suitable approach models, which may interpret the experimental wavy quantities, is the central idea of the present attempt, Furthermore, calculations with a little change of the initial conditions have been repeated in order to determine whether the plasma behaves as a chaotic medium.展开更多
[Objective]The aim was to study the interannual changes of atmospheric dust deposition and quantity of combustible dust-fall in Chaihe basin.[Method]Taking Chaihe Basin in south Dianchi as study area,the atmospheric d...[Objective]The aim was to study the interannual changes of atmospheric dust deposition and quantity of combustible dust-fall in Chaihe basin.[Method]Taking Chaihe Basin in south Dianchi as study area,the atmospheric dust deposition and combustible substances in the residential,chemical area,sand production area and watershed in Chaihe basin were measured.The pollution and interannual changes of atmospheric dust in Chaihe basin were discussed.[Result]In the residential,chemical area,sand production area and watershed,the amount of sand was the highest in sand production area and lowest in the watershed.While the dust amount in the chemical area and watershed areas were lower than sand production area and higher than watershed area.In the four chosen areas,the highest value of dust appeared in autumn and the lowest value appeared in precipitation season.Sand in other months changed and the change scale was large,which indicated that the meteorological condition had large influences on dust.Relevance analysis indicated that the dust in sand production area showed positive relevance to flammable amount of dust.Dust and flammable amount had positive relevance.[Conclusion]The study provided theoretical basis for the atmospheric pollution situation in Chaihe Basin.展开更多
文摘According to the data from Investigation Report of Land Use Change in China,The Land Resources Communique of China and Chronicle of Statistical Data for Five Decades of New China issued from Ministry of Land Resources,we select two indices:change of farmland quantity and policy of farmland protection.According to econometric theory,by using Eviewes 5.1 software,co-integration analysis,Granger causality test,impulse response and other analysis methods,we analyze the relationship between change of farmland quantity and policy of farmland protection in China since the reform and opening-up.The results show that there is long-term balanced relationship between change of farmland quantity and policy of farmland protection,and there is a certain mechanism restricting motion of variables between the two so as to make the two deviate from each other little and step towards balance in the long run;there is unilateral causality relationship between farmland change and policy of farmland protection,namely that the farmland change is the Granger cause of policy of farmland protection,while policy of farmland protection is not the Granger cause of farmland change;impulse response and variance decomposition indicate that farmland change plays the role of promoting policy of farmland protection continuously,and the role is strengthened along with prolonged lag period;the policy of farmland protection has strong inertia,because it is impacted by the former level of itself,and the policy of farmland protection plays insignificant role in promoting farmland quantity.Consequently,the important approach of solving problem of rapid decrease of farmland is to formulate long-term strategy,strengthen theoretical research of farmland protection and reinforce degree of formulation,implementation and surveillance of farmland protection policy.
文摘As is already known, most of the plasma literature is occupied with the plasma instabilities and the inevitable plasma waves, which remain major obstacles to the thermonuclear fusion process. Many experimental data on the plasma waves （growth or damping） and their accompanied theoretical interpretations have been published during the last five decades; lots of them have been identified and justified as well, some not yet. One of these is our previous research on plasma waves, which originated in the early 80＇s at the Plasma Physics Laboratory of the NCSR ＂Demokritos＂. As the wave rising is defined by the growth rate （or the damping on the extinguishment）, these important wavy quantities will be studied in detail in the present paper. Three examples are taken from our previous theoretical results, and the first observation reveals that the involved quantities are complicated enough to be studied by themselves. So, the use of suitable approach models, which may interpret the experimental wavy quantities, is the central idea of the present attempt, Furthermore, calculations with a little change of the initial conditions have been repeated in order to determine whether the plasma behaves as a chaotic medium.
文摘[Objective]The aim was to study the interannual changes of atmospheric dust deposition and quantity of combustible dust-fall in Chaihe basin.[Method]Taking Chaihe Basin in south Dianchi as study area,the atmospheric dust deposition and combustible substances in the residential,chemical area,sand production area and watershed in Chaihe basin were measured.The pollution and interannual changes of atmospheric dust in Chaihe basin were discussed.[Result]In the residential,chemical area,sand production area and watershed,the amount of sand was the highest in sand production area and lowest in the watershed.While the dust amount in the chemical area and watershed areas were lower than sand production area and higher than watershed area.In the four chosen areas,the highest value of dust appeared in autumn and the lowest value appeared in precipitation season.Sand in other months changed and the change scale was large,which indicated that the meteorological condition had large influences on dust.Relevance analysis indicated that the dust in sand production area showed positive relevance to flammable amount of dust.Dust and flammable amount had positive relevance.[Conclusion]The study provided theoretical basis for the atmospheric pollution situation in Chaihe Basin.
