The tangent resistance on the interface of the soil-moldboard is an important component of the resistance to moving soil . We developed simplified mechanical models to analyze this resistance. We found that it is comp...The tangent resistance on the interface of the soil-moldboard is an important component of the resistance to moving soil . We developed simplified mechanical models to analyze this resistance. We found that it is composed of two components, the frictional and adhesive resistances. These two components originate from the soil pore, which induced a capillary suction effect, and the soil-moldboard contact area produced tangent adhesive resistance. These two components varied differently with soil moisture. Thus we predicted that resistance reduction against soil exerted on the non-smooth bionic moldboard is mainly due to the elimination of capillary suction and the reduction of physical-chemical adsorption of soil.展开更多
A scanning electron microscope was used to observe the structures of the setae on the surface of a dung beetle Copris ochus, Motschulsky. There are lots of setae on the body surface, especially on the ventral part sur...A scanning electron microscope was used to observe the structures of the setae on the surface of a dung beetle Copris ochus, Motschulsky. There are lots of setae on the body surface, especially on the ventral part surface and lateral to the legs which are different in size, arrangement and shape. These setae have different lengths and many thorns on the whole seta. The top ends of these setae stand up without furcations which direct uprightly towards the surface of the touched soil. By the method of removing these setae, getting the insect weight before and after digging into the dung we affirm farther that the setae on the beetle body surface form the anti-stick and non-adherent gentle interface. The soil machines and components made by imitating the gentle body surface of beetles have favorable non-adherent results.展开更多
In order to solve the serious problems of soil adhesion and blockage as well as high operating resistance for wheat seeders under the condition of sticky heavy loam clay in rice-wheat rotation area,a new concept of no...In order to solve the serious problems of soil adhesion and blockage as well as high operating resistance for wheat seeders under the condition of sticky heavy loam clay in rice-wheat rotation area,a new concept of non-contact pneumatic seeding technology that could rip wheat seed into the soil by high pressure accelerating airflow was proposed in this paper.A preliminary bench experiment was conducted and high-speed photography technology was used to study the parameters of wheat pneumatic seeding under five levels(30%,35%,40%,45%and 50%)of soil moisture content for loam clay.Experimental results showed that:wheat seeds could be ripped into soil without damage and acquired varying degrees of germination by way of pneumatic seeding;shooting depth shown a deepening tendency with the increase in shooting velocity,and the value of seeding depth and seeding velocity are closely related to the soil moisture level,which wheat seeds can achieve higher shooting depth with relative lower shooting velocity when the soil moisture content increases continuously;none of wheat seeds could be ripped into the soil with about 2.93 m/s shooting velocity that accelerated in the form of free fall,while the shooting velocity that wheat seeds needed in order to be completely ripped into soil with 3 mm shooting depth were 40-50 m/s(30%soil moisture content),30-40 m/s(35%soil moisture content),20-30 m/s(40%soil moisture content),10-20 m/s(45%soil moisture content)and 2.93-10 m/s(20%soil moisture content),respectively.The experimental results can provide basic data and technical support for the development of non-contact wheat seeding equipment in rice-wheat rotation area.展开更多
基金sup port provided by the Key Project of Ministry of Edu-cation of P.R.China(Grant No.02089)the National Key Grant Program of Basic Research De-velopment(Grant No.2002CCA01200).
文摘The tangent resistance on the interface of the soil-moldboard is an important component of the resistance to moving soil . We developed simplified mechanical models to analyze this resistance. We found that it is composed of two components, the frictional and adhesive resistances. These two components originate from the soil pore, which induced a capillary suction effect, and the soil-moldboard contact area produced tangent adhesive resistance. These two components varied differently with soil moisture. Thus we predicted that resistance reduction against soil exerted on the non-smooth bionic moldboard is mainly due to the elimination of capillary suction and the reduction of physical-chemical adsorption of soil.
文摘A scanning electron microscope was used to observe the structures of the setae on the surface of a dung beetle Copris ochus, Motschulsky. There are lots of setae on the body surface, especially on the ventral part surface and lateral to the legs which are different in size, arrangement and shape. These setae have different lengths and many thorns on the whole seta. The top ends of these setae stand up without furcations which direct uprightly towards the surface of the touched soil. By the method of removing these setae, getting the insect weight before and after digging into the dung we affirm farther that the setae on the beetle body surface form the anti-stick and non-adherent gentle interface. The soil machines and components made by imitating the gentle body surface of beetles have favorable non-adherent results.
基金This paper was funded by the Program for China Agriculture Research System(CARS-03)and Changjiang Scholars,Innovative Research Team in University of China(Grant No.IRT13039).Gratitude should be expressed to all the members of Conservation Tillage Research Centre.
文摘In order to solve the serious problems of soil adhesion and blockage as well as high operating resistance for wheat seeders under the condition of sticky heavy loam clay in rice-wheat rotation area,a new concept of non-contact pneumatic seeding technology that could rip wheat seed into the soil by high pressure accelerating airflow was proposed in this paper.A preliminary bench experiment was conducted and high-speed photography technology was used to study the parameters of wheat pneumatic seeding under five levels(30%,35%,40%,45%and 50%)of soil moisture content for loam clay.Experimental results showed that:wheat seeds could be ripped into soil without damage and acquired varying degrees of germination by way of pneumatic seeding;shooting depth shown a deepening tendency with the increase in shooting velocity,and the value of seeding depth and seeding velocity are closely related to the soil moisture level,which wheat seeds can achieve higher shooting depth with relative lower shooting velocity when the soil moisture content increases continuously;none of wheat seeds could be ripped into the soil with about 2.93 m/s shooting velocity that accelerated in the form of free fall,while the shooting velocity that wheat seeds needed in order to be completely ripped into soil with 3 mm shooting depth were 40-50 m/s(30%soil moisture content),30-40 m/s(35%soil moisture content),20-30 m/s(40%soil moisture content),10-20 m/s(45%soil moisture content)and 2.93-10 m/s(20%soil moisture content),respectively.The experimental results can provide basic data and technical support for the development of non-contact wheat seeding equipment in rice-wheat rotation area.
