In irrigation schemes under rotational water supply in semiarid region, the water allocation and irrigation scheduling are often based on a fixed-area proportionate water depth with every irrigation cycle irrespective...In irrigation schemes under rotational water supply in semiarid region, the water allocation and irrigation scheduling are often based on a fixed-area proportionate water depth with every irrigation cycle irrespective of crops and their growth stages, for an equitable water supply. An experiment was conducted during the 2004- 2005 season in Haouz irrigated area in Morocco, which objective was i) to evaluate the effects of the surface irrigation scheduling method (existing rule) adopted by the irrigation agency on winter wheat production compared to a full irrigation method and ii) to evaluate drip irrigation versus surface irrigation impacts on water saving and yield of winter wheat. The methodology was based on the FAO-56 dual approach for the surface irrigation scheduling. Ground measurements of the Normalized Difference Vegetation Index (NDVI) were used to derive the basal crop coefficient and the vegetation fraction cover. The simple FAO-56 approach was used for drip irrigation scheduling. For surface irrigation, the existing rule approach resulted in yield and WUE reductions of 22% and 15%, respectively, compared with the optimized irrigation scheduling proposed by the FAO-56 for full irrigation treatment. This revealed the negative effects of the irrigation schedules adopted in irrigation schemes under rotational water supply on crops productivity. It was also demon-strated that drip irrigation applied to wheat was more efficient with 20% of water saving in comparison with surface irrigation (full irrigation treatment). Drip irrigation gives also higher wheat yield compared to surface irrigation (+28% and +52% for full irrigation and existing rule treatments respectively). The same improvement was observed for water use efficiency (+24 and +59% respectively).展开更多
The Chinese economy has been experiencing extensive growth for decades. Along with this growth, however, there have been industrial-economic, social and environmental inefficiencies. In some regions, problems exist be...The Chinese economy has been experiencing extensive growth for decades. Along with this growth, however, there have been industrial-economic, social and environmental inefficiencies. In some regions, problems exist because of overemphasis on GDP growth, or growth at the expense of the environment. Looking at efficiency through the prism of economic, social and environmental factors, this article analyzes the industrial economic development during the 10th Five-Year Plan (2001-2005). The authors conclude that economic development should be achieved while making overall improvements to economic, social and ecoenvironment efficiency.展开更多
We select 34 representative agricultural listed companies as the study object,to analyze the characteristics of quick assets in agricultural companies.The ratio between quick assets and total assets roughly displays n...We select 34 representative agricultural listed companies as the study object,to analyze the characteristics of quick assets in agricultural companies.The ratio between quick assets and total assets roughly displays normal distribution,with the peak value up to 40%;the distribution figure shape of the ratio between quick assets and liquid asset displays normal distribution,with the peak value up to 63%.Taking the case of typical agricultural company,Yuan Longping High-Tech Agriculture Co.,Ltd.,we analyze the factors influencing turnover of quick assets,and the main factors influencing the turnover of quick assets in agricultural companies are monetary funds and receivables.We establish the multiple linear regression model,and draw the conclusion that the turnover efficiency of quick assets is significantly affected by the ratio between cash assets and income,turnover rate of receivables,and quickness ratio.展开更多
By setting the urban-rural public goods supply model,this paper evaluates the effects of coordinating supply public goods on resource allocation and welfare from efficiency and fairness,and examines the necessity and ...By setting the urban-rural public goods supply model,this paper evaluates the effects of coordinating supply public goods on resource allocation and welfare from efficiency and fairness,and examines the necessity and possibility of coordinating public goods supply in urban and rural areas. The model assumes that the population size of urban and rural areas is different,and the population can not flow freely between urban and rural areas; there are different degrees of spillover in the public goods supply. Model results show that coordinating public goods supply in urban and rural areas is the result of optimizing resource allocation efficiency,but the residents' individual utility level will not necessarily improve,so residents' willingness to support coordinated urban-rural supply is different,and public goods spillover and different tax systems are the factors that affect the residents' utility level. Finally,this paper uses the practice of coordinating urban and rural compulsory education in Chengdu City to confirm the above conclusions.展开更多
To obtain high efficiency luminescent materials, the system Al2O3-B2O3 containing Ce3+ andTb3+ ions with variation of B2O3-content, has been prepared by Al2O3, H3BO3, CeO2 and Tb4O7 underreducing atmosphere at 1250i ....To obtain high efficiency luminescent materials, the system Al2O3-B2O3 containing Ce3+ andTb3+ ions with variation of B2O3-content, has been prepared by Al2O3, H3BO3, CeO2 and Tb4O7 underreducing atmosphere at 1250i . It is notable that the brightness of the sample with appropriatecomposition is similar to that of commercial phosphorous containing Ce3+ and Tb3+, indicating that a newhigh efficency green luminescent material was obtained with appropriate B2O3-content.展开更多
Marine macroalgae cultivation is an important part of the effort to address climate change through carbon sinks.Gracilaria,especially Gracilaria lemaneiformis and Gracilaria lichenoides are the major macroalgae cultiv...Marine macroalgae cultivation is an important part of the effort to address climate change through carbon sinks.Gracilaria,especially Gracilaria lemaneiformis and Gracilaria lichenoides are the major macroalgae cultivated in China.This study proposes a method to assess the net carbon sink of marine macroalgae(Gracilaria)cultivation.First,the net carbon sink of Gracilaria cultivation in China is calculated based on the yield of annual cultivated Gracilaria recorded in China Fishery Statistical Yearbook from 2011 to 2020.Next,we predict the net carbon sink trend of Gracilaria cultivation from 2021 to 2030 using the autoregressive integrated moving average model(ARIMA).Finally,the potential carbon sink increase and methane reduction related to Gracilaria cultivation in China is explored through a scenario analysis.We find that the net carbon sink of Gracilaria cultivation in China was about 32.1-92.4 kilotons per year from 2011 to 2020,and shows a great annual growth trend.Moreover,the predicted net carbon sink of Gracilaria cultivation would increase to 77.8-191.4 kilotons per year from 2021 to2030,thereby could contribute considerably in the achievement of China's carbon peak goal.Under a scenario of producing ruminant green feed with additional Gracilaria cultivation,each ton of macroalgae is predicted to reduce carbon emission(i.e.,methane)by 0.33-0.68 tons.Thus,marine macroalgae cultivation might form a synergistic chain of"carbon sink increase-water purification-economy-methane reduction".This study proposes a synergistic new model that operates through marine macroalgae cultivation,economic aquaculture,and green feed production.展开更多
文摘In irrigation schemes under rotational water supply in semiarid region, the water allocation and irrigation scheduling are often based on a fixed-area proportionate water depth with every irrigation cycle irrespective of crops and their growth stages, for an equitable water supply. An experiment was conducted during the 2004- 2005 season in Haouz irrigated area in Morocco, which objective was i) to evaluate the effects of the surface irrigation scheduling method (existing rule) adopted by the irrigation agency on winter wheat production compared to a full irrigation method and ii) to evaluate drip irrigation versus surface irrigation impacts on water saving and yield of winter wheat. The methodology was based on the FAO-56 dual approach for the surface irrigation scheduling. Ground measurements of the Normalized Difference Vegetation Index (NDVI) were used to derive the basal crop coefficient and the vegetation fraction cover. The simple FAO-56 approach was used for drip irrigation scheduling. For surface irrigation, the existing rule approach resulted in yield and WUE reductions of 22% and 15%, respectively, compared with the optimized irrigation scheduling proposed by the FAO-56 for full irrigation treatment. This revealed the negative effects of the irrigation schedules adopted in irrigation schemes under rotational water supply on crops productivity. It was also demon-strated that drip irrigation applied to wheat was more efficient with 20% of water saving in comparison with surface irrigation (full irrigation treatment). Drip irrigation gives also higher wheat yield compared to surface irrigation (+28% and +52% for full irrigation and existing rule treatments respectively). The same improvement was observed for water use efficiency (+24 and +59% respectively).
文摘The Chinese economy has been experiencing extensive growth for decades. Along with this growth, however, there have been industrial-economic, social and environmental inefficiencies. In some regions, problems exist because of overemphasis on GDP growth, or growth at the expense of the environment. Looking at efficiency through the prism of economic, social and environmental factors, this article analyzes the industrial economic development during the 10th Five-Year Plan (2001-2005). The authors conclude that economic development should be achieved while making overall improvements to economic, social and ecoenvironment efficiency.
文摘We select 34 representative agricultural listed companies as the study object,to analyze the characteristics of quick assets in agricultural companies.The ratio between quick assets and total assets roughly displays normal distribution,with the peak value up to 40%;the distribution figure shape of the ratio between quick assets and liquid asset displays normal distribution,with the peak value up to 63%.Taking the case of typical agricultural company,Yuan Longping High-Tech Agriculture Co.,Ltd.,we analyze the factors influencing turnover of quick assets,and the main factors influencing the turnover of quick assets in agricultural companies are monetary funds and receivables.We establish the multiple linear regression model,and draw the conclusion that the turnover efficiency of quick assets is significantly affected by the ratio between cash assets and income,turnover rate of receivables,and quickness ratio.
基金Supported by Fundamental Research Funds for Central Universities,Southwest University(SWU1109028)Southwest University Youth Foundation(SWU07104)Key Humanities and Social Sciences Research Project in Chongqing City(13SKB022)
文摘By setting the urban-rural public goods supply model,this paper evaluates the effects of coordinating supply public goods on resource allocation and welfare from efficiency and fairness,and examines the necessity and possibility of coordinating public goods supply in urban and rural areas. The model assumes that the population size of urban and rural areas is different,and the population can not flow freely between urban and rural areas; there are different degrees of spillover in the public goods supply. Model results show that coordinating public goods supply in urban and rural areas is the result of optimizing resource allocation efficiency,but the residents' individual utility level will not necessarily improve,so residents' willingness to support coordinated urban-rural supply is different,and public goods spillover and different tax systems are the factors that affect the residents' utility level. Finally,this paper uses the practice of coordinating urban and rural compulsory education in Chengdu City to confirm the above conclusions.
文摘To obtain high efficiency luminescent materials, the system Al2O3-B2O3 containing Ce3+ andTb3+ ions with variation of B2O3-content, has been prepared by Al2O3, H3BO3, CeO2 and Tb4O7 underreducing atmosphere at 1250i . It is notable that the brightness of the sample with appropriatecomposition is similar to that of commercial phosphorous containing Ce3+ and Tb3+, indicating that a newhigh efficency green luminescent material was obtained with appropriate B2O3-content.
基金supported by the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.SML2021SP203)。
文摘Marine macroalgae cultivation is an important part of the effort to address climate change through carbon sinks.Gracilaria,especially Gracilaria lemaneiformis and Gracilaria lichenoides are the major macroalgae cultivated in China.This study proposes a method to assess the net carbon sink of marine macroalgae(Gracilaria)cultivation.First,the net carbon sink of Gracilaria cultivation in China is calculated based on the yield of annual cultivated Gracilaria recorded in China Fishery Statistical Yearbook from 2011 to 2020.Next,we predict the net carbon sink trend of Gracilaria cultivation from 2021 to 2030 using the autoregressive integrated moving average model(ARIMA).Finally,the potential carbon sink increase and methane reduction related to Gracilaria cultivation in China is explored through a scenario analysis.We find that the net carbon sink of Gracilaria cultivation in China was about 32.1-92.4 kilotons per year from 2011 to 2020,and shows a great annual growth trend.Moreover,the predicted net carbon sink of Gracilaria cultivation would increase to 77.8-191.4 kilotons per year from 2021 to2030,thereby could contribute considerably in the achievement of China's carbon peak goal.Under a scenario of producing ruminant green feed with additional Gracilaria cultivation,each ton of macroalgae is predicted to reduce carbon emission(i.e.,methane)by 0.33-0.68 tons.Thus,marine macroalgae cultivation might form a synergistic chain of"carbon sink increase-water purification-economy-methane reduction".This study proposes a synergistic new model that operates through marine macroalgae cultivation,economic aquaculture,and green feed production.