Exposure of whole body vibration(WBV)influences performance,comfort,and long term health risks of tractor operator.Therefore,measurement and evaluation of WBV parameters should be carried out to find probable effects ...Exposure of whole body vibration(WBV)influences performance,comfort,and long term health risks of tractor operator.Therefore,measurement and evaluation of WBV parameters should be carried out to find probable effects on the health of tractor operators.In this study,a system was designed to measure the WBV of agricultural tractor operators and evaluated the hazard risks on operator’s body according to the ISO standards,and implementation of the WBV test in the official testing station was also suggested.A tri-axial accelerometer was employed to measure vibrations transmitted to the seated operator body as a whole through the supporting surface of the buttock on four typical farm roads under different speeds.The vector sum A(8)exposures on the rough tracks(earthen and grassland roads)exceeded the action limits of 0.5 m/s2 at a 10.9 km/h forward speed and reached to the action limit value at a 16.0 km/h forward speed on the concrete road.The vector sum of VDV(8)exposures did not exceed the action limits of 9.1 m/s1.75 and was greater on the grassland road.The vector sum Sed(8)exposures values exceeded the moderate probability of an adverse health limit of 0.5 MPa on all farm roads at high forward speeds and exceeded the high probability of an adverse health limit of 0.8 MPa on asphalt,concrete,and grassland roads which should be lower than the exposure limit values as suggested by the ISO and EC standards.The WBV evaluation procedure should be considered for implementation at the official tractor test station,which would response to domestic and international tractor test regulations and improve the market competitiveness.展开更多
Under the"separation of three rights"policy,the impact of security of land operationalrights on agricultural production efficiency has attracted much attention in recentyears.Data envelopment analysis and me...Under the"separation of three rights"policy,the impact of security of land operationalrights on agricultural production efficiency has attracted much attention in recentyears.Data envelopment analysis and mediation effect analysis were applied to 888family farms run by new-type agricultural operators from Songjiang to identify themechanism of the effect of land operational rights security on agricultural productionefficiency through long-term investment.The results show that greater security of landoperational rights generally increased agricultural production efficiency.Approximately37.94 percent of the impact could be explained by long-term investment.The resultsalso indicate that significant heterogeneity exists in the effect of land operational rightssecurity on agricultural production efficiency at various levels of the family farms'efficiency distributions.lt is suggested that government should legalize land operationalrights and give them a status equal to those of households'contractual rights and landownership rights in China's future land tenure reform.展开更多
As socialism with Chinese characteristics enters a new era,China's agricultural and rural development has also made remarkable achievements.However,the shortcomings of modernization are still in the field of agric...As socialism with Chinese characteristics enters a new era,China's agricultural and rural development has also made remarkable achievements.However,the shortcomings of modernization are still in the field of agriculture,rural areas and farmers.The report of the 19th National Congress of the Communist Party of China proposes a strategy of rural revitalization.It is pointed out that the organic connection between small farmers and modern agricultural development should be promoted.In the development of modern agriculture,small farmers face the problems of scattered production factors,aging labor force and low labor quality,low industrialization,and low market position.This paper compares the characteristics of farmer cooperatives with other new business entities.Combined with the relevant contents of the Law of the People's Republic of China on Farmers'Professional Cooperatives newly revised in 2017,this paper analyzes the organizational,service,and intermediary functions of farmers'cooperatives to promote the organic connection between small farmers and modern agriculture development and reveals the role of farmers'cooperatives in China's agricultural development.展开更多
文摘Exposure of whole body vibration(WBV)influences performance,comfort,and long term health risks of tractor operator.Therefore,measurement and evaluation of WBV parameters should be carried out to find probable effects on the health of tractor operators.In this study,a system was designed to measure the WBV of agricultural tractor operators and evaluated the hazard risks on operator’s body according to the ISO standards,and implementation of the WBV test in the official testing station was also suggested.A tri-axial accelerometer was employed to measure vibrations transmitted to the seated operator body as a whole through the supporting surface of the buttock on four typical farm roads under different speeds.The vector sum A(8)exposures on the rough tracks(earthen and grassland roads)exceeded the action limits of 0.5 m/s2 at a 10.9 km/h forward speed and reached to the action limit value at a 16.0 km/h forward speed on the concrete road.The vector sum of VDV(8)exposures did not exceed the action limits of 9.1 m/s1.75 and was greater on the grassland road.The vector sum Sed(8)exposures values exceeded the moderate probability of an adverse health limit of 0.5 MPa on all farm roads at high forward speeds and exceeded the high probability of an adverse health limit of 0.8 MPa on asphalt,concrete,and grassland roads which should be lower than the exposure limit values as suggested by the ISO and EC standards.The WBV evaluation procedure should be considered for implementation at the official tractor test station,which would response to domestic and international tractor test regulations and improve the market competitiveness.
基金the National Natural Science Foundation of China(No.71673234)the Ministry of Education Foundation of China(No.16JZD024)and the Six Key Industries Talent Paramount Program of Jiangsu Province,China.
文摘Under the"separation of three rights"policy,the impact of security of land operationalrights on agricultural production efficiency has attracted much attention in recentyears.Data envelopment analysis and mediation effect analysis were applied to 888family farms run by new-type agricultural operators from Songjiang to identify themechanism of the effect of land operational rights security on agricultural productionefficiency through long-term investment.The results show that greater security of landoperational rights generally increased agricultural production efficiency.Approximately37.94 percent of the impact could be explained by long-term investment.The resultsalso indicate that significant heterogeneity exists in the effect of land operational rightssecurity on agricultural production efficiency at various levels of the family farms'efficiency distributions.lt is suggested that government should legalize land operationalrights and give them a status equal to those of households'contractual rights and landownership rights in China's future land tenure reform.
基金Planning Fund for Humanities and Social Sciences Research of the Ministry of Education in 2020(20YJA790044)Sichuan Science and Technology Plan Project(2019JDR0136)+2 种基金General Project of Sichuan Mineral Resources Research Center(SCKCZY2017-YB02)Project of Rural Industry Promotion Research Center of Chengdu University of Technology(YJ2017-JD005)Research on the Institution and Mechanism of the Deep Integrational Development of Urban-rural Areas under the Background of Rural Revitalization Strategy(20YJA790044).
文摘As socialism with Chinese characteristics enters a new era,China's agricultural and rural development has also made remarkable achievements.However,the shortcomings of modernization are still in the field of agriculture,rural areas and farmers.The report of the 19th National Congress of the Communist Party of China proposes a strategy of rural revitalization.It is pointed out that the organic connection between small farmers and modern agricultural development should be promoted.In the development of modern agriculture,small farmers face the problems of scattered production factors,aging labor force and low labor quality,low industrialization,and low market position.This paper compares the characteristics of farmer cooperatives with other new business entities.Combined with the relevant contents of the Law of the People's Republic of China on Farmers'Professional Cooperatives newly revised in 2017,this paper analyzes the organizational,service,and intermediary functions of farmers'cooperatives to promote the organic connection between small farmers and modern agriculture development and reveals the role of farmers'cooperatives in China's agricultural development.
