A high grain breakage rate is the main problem that occurs during mechanical maize harvest in China.The breakage sensitivity of different varieties was significantly different,and the breakage resistance is heritable....A high grain breakage rate is the main problem that occurs during mechanical maize harvest in China.The breakage sensitivity of different varieties was significantly different,and the breakage resistance is heritable.Therefore,breakage resistant variety screening can help improve the field production efficiency and provide references for breeding work.In this study,42 varieties of maize were harvested with the same mechanical parameters and the same manipulator on a range of harvest dates at experimental stations in Xinxiang,Henan Province,in 2017 and Changji,Xinjiang Province,in 2018 to determine the sensitivity of grain moisture content on grain breakage rate during machine harvest for different varieties.The integral value of the grain breakage rate curve corresponding to the range of 15%to 30%grain moisture content was used as an index that expressed the sensitivity of maize grains to breakage depending on grain moisture content(BSW).Forty-two varieties were categorized as having weak,intermediate,or strong BSW.Among the same four varieties in the two stations,Lianchuang 825 and Lianchuang 808 were classified as sensitive and fragile varieties,Shandan 650 was classified as an intermediate variety,Zeyu 8911 was divided into weak sensitive and breakage-resistance varieties in Xinxiang and intermediate varieties in Changji.The BSW classification results at the two experimental sites were generally consistent,indicating that breakage sensitivity due to moisture content may be a relatively stable genetic characteristic.This study suggested that the integral method for determining BSW can be used to assess the resistance of different maize varieties to grain breakage during mechanical harvesting.The integral method was used to identify twelve breakage-resistant varieties in Xinxiang Station,and six breakage-resistant varieties in Changji Station.This study provides a method for screening maize varieties that are suited to mechanical grain harvesting and for studying the mechanisms of grain breakage resistance.展开更多
In this paper, using the theory of stochastic analysis of the response to earthquake load, a stochastic analysis method of the response of piled platforms to earthquake load has been established. In the method, the st...In this paper, using the theory of stochastic analysis of the response to earthquake load, a stochastic analysis method of the response of piled platforms to earthquake load has been established. In the method, the strong ground motion is considered as three dimensional stationary white noise process and the pile-soil interaction and water-structure interaction are considered. The stochastic response of a typical platform to earthquake load has been computed with this method and the results compared with those obtained with the response spectrum analysis method. The comparison shows that the stochastic analysis method of the response of piled platforms to earthquake load is suitable for this kind of analysis.展开更多
Tehran is located in the Alborz’s mountain range subsidence and alluvial deposits which are formed in the different faults. Though these faults caused changes in Northern Tehran’s alluvium. The geomechanics factors ...Tehran is located in the Alborz’s mountain range subsidence and alluvial deposits which are formed in the different faults. Though these faults caused changes in Northern Tehran’s alluvium. The geomechanics factors on these alluviums made northern area of Tehran a dangerous place to construct. In this article we have tried to determine the zone’s resistance [1], critical depth in excavation and in the end the role of faults in mechanical resistance of alluvium by comparing several pits in the zone of fault or the zone with no fault. For this purpose, the impact of the neighboring building on the pit stability has been investigated in several locations in some part of coarse alluvium of northern Tehran. So engineering methods such as numerical method and limit equilibrium with the help of software like FLAC and SLIDE were used to determine alluvium’s resistance and the critical depth of excavation. It was done in a way that several pits were analyzed and evaluated in the studied area to a depth of 20 meters in the unloaded state of the neighboring buildings, and once even the load of a neighboring 5-storey building placed at a distance of 3 meters from the edge of the considered pit was analyzed and the results were compared.展开更多
The utilization of fiber reinforced thermoplastics(FRTP)is expected to fulfill lightweight demand in mass-produced aerospace products.Facing the unavoidable assembly of FRTP parts,fusion bonding methods such as resist...The utilization of fiber reinforced thermoplastics(FRTP)is expected to fulfill lightweight demand in mass-produced aerospace products.Facing the unavoidable assembly of FRTP parts,fusion bonding methods such as resistance welding are promising compared with mechanical joint and adhesive bonding.In this paper,a procedure has been brought out to understand the relationship between processing conditions and performance of the FRTP welding joints.The adherends were continuous glass fiber reinforced polypropylene(GF/PP)laminates fabricated by hotpressing method.The influences of time,current and pressure on the bending strength of the resistance welding joints were investigated.A processing window was drawn based on the optical observation of welded surfaces.The quantitative relationship between process parameters and mechanical property of GF/PP welding joint was established by Response Surface Method(RSM)with high accuracy.It was found that bending strength of GF/PP welding joint was improved by 31%compared with hot-pressing benchmark.展开更多
基金This work was financially supported by the National Key Research and Development Program of China(2016YFD0300110,2016YFD0300101)the National Natural Science Foundation of China(31371575)+1 种基金the China Agriculture Research System(CARS-02-25)the Agricultural Science and Technology Innovation Project of the Chinese Academy of Agricultural Science.
文摘A high grain breakage rate is the main problem that occurs during mechanical maize harvest in China.The breakage sensitivity of different varieties was significantly different,and the breakage resistance is heritable.Therefore,breakage resistant variety screening can help improve the field production efficiency and provide references for breeding work.In this study,42 varieties of maize were harvested with the same mechanical parameters and the same manipulator on a range of harvest dates at experimental stations in Xinxiang,Henan Province,in 2017 and Changji,Xinjiang Province,in 2018 to determine the sensitivity of grain moisture content on grain breakage rate during machine harvest for different varieties.The integral value of the grain breakage rate curve corresponding to the range of 15%to 30%grain moisture content was used as an index that expressed the sensitivity of maize grains to breakage depending on grain moisture content(BSW).Forty-two varieties were categorized as having weak,intermediate,or strong BSW.Among the same four varieties in the two stations,Lianchuang 825 and Lianchuang 808 were classified as sensitive and fragile varieties,Shandan 650 was classified as an intermediate variety,Zeyu 8911 was divided into weak sensitive and breakage-resistance varieties in Xinxiang and intermediate varieties in Changji.The BSW classification results at the two experimental sites were generally consistent,indicating that breakage sensitivity due to moisture content may be a relatively stable genetic characteristic.This study suggested that the integral method for determining BSW can be used to assess the resistance of different maize varieties to grain breakage during mechanical harvesting.The integral method was used to identify twelve breakage-resistant varieties in Xinxiang Station,and six breakage-resistant varieties in Changji Station.This study provides a method for screening maize varieties that are suited to mechanical grain harvesting and for studying the mechanisms of grain breakage resistance.
文摘In this paper, using the theory of stochastic analysis of the response to earthquake load, a stochastic analysis method of the response of piled platforms to earthquake load has been established. In the method, the strong ground motion is considered as three dimensional stationary white noise process and the pile-soil interaction and water-structure interaction are considered. The stochastic response of a typical platform to earthquake load has been computed with this method and the results compared with those obtained with the response spectrum analysis method. The comparison shows that the stochastic analysis method of the response of piled platforms to earthquake load is suitable for this kind of analysis.
文摘Tehran is located in the Alborz’s mountain range subsidence and alluvial deposits which are formed in the different faults. Though these faults caused changes in Northern Tehran’s alluvium. The geomechanics factors on these alluviums made northern area of Tehran a dangerous place to construct. In this article we have tried to determine the zone’s resistance [1], critical depth in excavation and in the end the role of faults in mechanical resistance of alluvium by comparing several pits in the zone of fault or the zone with no fault. For this purpose, the impact of the neighboring building on the pit stability has been investigated in several locations in some part of coarse alluvium of northern Tehran. So engineering methods such as numerical method and limit equilibrium with the help of software like FLAC and SLIDE were used to determine alluvium’s resistance and the critical depth of excavation. It was done in a way that several pits were analyzed and evaluated in the studied area to a depth of 20 meters in the unloaded state of the neighboring buildings, and once even the load of a neighboring 5-storey building placed at a distance of 3 meters from the edge of the considered pit was analyzed and the results were compared.
基金Supports from the National Natural Science Foundation of China(Nos.11972096 and 11572059)CAST Young Elite Scientists Sponsorship Program(2017QNRC001)+3 种基金Chinese-Foreign Excellent Youth Exchange Program(2017CASTQNJL042)Fundamental Research Funds for the Central Universities(2018CDQYHK0029)Chongqing Key R&D Program(cstc2017zdcy-zdyfX0005)Chongqing Natural Science Foundation(cstc2018jcyjAX0089)。
文摘The utilization of fiber reinforced thermoplastics(FRTP)is expected to fulfill lightweight demand in mass-produced aerospace products.Facing the unavoidable assembly of FRTP parts,fusion bonding methods such as resistance welding are promising compared with mechanical joint and adhesive bonding.In this paper,a procedure has been brought out to understand the relationship between processing conditions and performance of the FRTP welding joints.The adherends were continuous glass fiber reinforced polypropylene(GF/PP)laminates fabricated by hotpressing method.The influences of time,current and pressure on the bending strength of the resistance welding joints were investigated.A processing window was drawn based on the optical observation of welded surfaces.The quantitative relationship between process parameters and mechanical property of GF/PP welding joint was established by Response Surface Method(RSM)with high accuracy.It was found that bending strength of GF/PP welding joint was improved by 31%compared with hot-pressing benchmark.
