Element a in ring R is called centrally clean if it is the sum of central idempotent e and unit u.Moreover,a=e+u is called a centrally clean decomposition of a and R is called a centrally clean ring if every element o...Element a in ring R is called centrally clean if it is the sum of central idempotent e and unit u.Moreover,a=e+u is called a centrally clean decomposition of a and R is called a centrally clean ring if every element of R is centrally clean.First,some characterizations of centrally clean elements are given.Furthermore,some properties of centrally clean rings,as well as the necessary and sufficient conditions for R to be a centrally clean ring are investigated.Centrally clean rings are closely related to the central Drazin inverses.Then,in terms of centrally clean decomposition,the necessary and sufficient conditions for the existence of central Drazin inverses are presented.Moreover,the central cleanness of special rings,such as corner rings,the ring of formal power series over ring R,and a direct product ∏ R_(α) of ring R_(α),is analyzed.Furthermore,the central group invertibility of combinations of two central idempotents in the algebra over a field is investigated.Finally,as an application,an example that lists all invertible,central group invertible,group invertible,central Drazin invertible elements,and centrally clean elements of the group ring Z_(2)S_(3) is given.展开更多
The laws of influence of different factors have been analyzed in order to enhance the working efficiency and fatigue life of the cleaning element in brush shape of the sugarcane harvester. Based on the principle of or...The laws of influence of different factors have been analyzed in order to enhance the working efficiency and fatigue life of the cleaning element in brush shape of the sugarcane harvester. Based on the principle of orthogonal experiment design, the virtual-orthogonal-experimental analysis for the cleaning element is carried out on the finite element analysis （FEA） software-ANSYS after analyzing the nonlinear structural behavior in the working procedure. The results are analyzed with the overall balancing method, and then the optimal combination is got, which is made up of different levels of different factors. Also the optimal combination of design parameters of the cleaning element received fiom the virtual experimental analysis is conducted an experiment to confirm that the virtual analysis model and results are right, and the effect of factors on the function of the cleaning element is obtained by more analysis and further optimizing.展开更多
The cleaning element is the key part to the small w ho le-stall sugarcane harvester, which is suitable to the highland. And it is the bottleneck of the design of the small sugarcane harvester. The working mechanism of...The cleaning element is the key part to the small w ho le-stall sugarcane harvester, which is suitable to the highland. And it is the bottleneck of the design of the small sugarcane harvester. The working mechanism of centrifugal cleaning method of the cleaning element in brush shape is based on the high speed rotating cleaning element that push, scrub, and strike the sta lk to separate the leaves from the sugarcane. The paper elaborated the worki ng mechanism of cleaning element in brush shape of the sugarcane harvester, and analyzed the state of cleaning procedure and the reacting force that the cleanin g element was subjected. Combined with the earlier stage experiments and researc hes, it was found out that the factors, which affect the cleaning efficiency and fatigue life of cleaning element, were quite many, and the factors were complex and random. So it was difficult to analyze and design cleaning element in theor y. Moreover, if the design parameters were got from experiment it would be time consuming, laborious, and costly. The method of numerical value simulation ortho gonal experiment is used to analyze the reacting force by means of establishing finite element analysis model for cleaning element on ANSYS. According to orthog onal experiment principle, the different parameter groups were made to do finite element calculation. And then orthogonal experiment analysis and regression ana lysis were made to find out the effect on the calculated result that was caused by the changes of different parameter groups, and get optimal design parameters of cleaning element. In conclusion, this virtual design method is a quick and ef ficient way in innovative mechanical product design. This method economizes mate rial, labor, and time, and then it is the right way of high efficiency and speed to reduce the development period, and increase the quality of product and the r atio of successful development at once.展开更多
The exchange rings without unity, first introduced by Ara, are further investigated. Some new characterizations and properties of exchange general rings are given. For example, a general ring I is exchange if and only...The exchange rings without unity, first introduced by Ara, are further investigated. Some new characterizations and properties of exchange general rings are given. For example, a general ring I is exchange if and only if for any left ideal L of I and a^-= a^-2 ∈I/L, there exists w ∈ r. ureg（I） such that w^- = a^-; E（R, I） （ the ideal extension of a ring R by its ideal I） is an exchange ring if and only if R and I are both exchange. Furthermore, it is presented that if I is a two-sided ideal of a unital ring R and I is an exchange general ring, then every central element of I is a clean element in 1.展开更多
基金The National Natural Science Foundation of China(No.12171083,11871145,12071070)the Qing Lan Project of Jiangsu Province。
文摘Element a in ring R is called centrally clean if it is the sum of central idempotent e and unit u.Moreover,a=e+u is called a centrally clean decomposition of a and R is called a centrally clean ring if every element of R is centrally clean.First,some characterizations of centrally clean elements are given.Furthermore,some properties of centrally clean rings,as well as the necessary and sufficient conditions for R to be a centrally clean ring are investigated.Centrally clean rings are closely related to the central Drazin inverses.Then,in terms of centrally clean decomposition,the necessary and sufficient conditions for the existence of central Drazin inverses are presented.Moreover,the central cleanness of special rings,such as corner rings,the ring of formal power series over ring R,and a direct product ∏ R_(α) of ring R_(α),is analyzed.Furthermore,the central group invertibility of combinations of two central idempotents in the algebra over a field is investigated.Finally,as an application,an example that lists all invertible,central group invertible,group invertible,central Drazin invertible elements,and centrally clean elements of the group ring Z_(2)S_(3) is given.
基金This project is supported by National Natural Science Foundation of China(No.50365001).
文摘The laws of influence of different factors have been analyzed in order to enhance the working efficiency and fatigue life of the cleaning element in brush shape of the sugarcane harvester. Based on the principle of orthogonal experiment design, the virtual-orthogonal-experimental analysis for the cleaning element is carried out on the finite element analysis （FEA） software-ANSYS after analyzing the nonlinear structural behavior in the working procedure. The results are analyzed with the overall balancing method, and then the optimal combination is got, which is made up of different levels of different factors. Also the optimal combination of design parameters of the cleaning element received fiom the virtual experimental analysis is conducted an experiment to confirm that the virtual analysis model and results are right, and the effect of factors on the function of the cleaning element is obtained by more analysis and further optimizing.
文摘The cleaning element is the key part to the small w ho le-stall sugarcane harvester, which is suitable to the highland. And it is the bottleneck of the design of the small sugarcane harvester. The working mechanism of centrifugal cleaning method of the cleaning element in brush shape is based on the high speed rotating cleaning element that push, scrub, and strike the sta lk to separate the leaves from the sugarcane. The paper elaborated the worki ng mechanism of cleaning element in brush shape of the sugarcane harvester, and analyzed the state of cleaning procedure and the reacting force that the cleanin g element was subjected. Combined with the earlier stage experiments and researc hes, it was found out that the factors, which affect the cleaning efficiency and fatigue life of cleaning element, were quite many, and the factors were complex and random. So it was difficult to analyze and design cleaning element in theor y. Moreover, if the design parameters were got from experiment it would be time consuming, laborious, and costly. The method of numerical value simulation ortho gonal experiment is used to analyze the reacting force by means of establishing finite element analysis model for cleaning element on ANSYS. According to orthog onal experiment principle, the different parameter groups were made to do finite element calculation. And then orthogonal experiment analysis and regression ana lysis were made to find out the effect on the calculated result that was caused by the changes of different parameter groups, and get optimal design parameters of cleaning element. In conclusion, this virtual design method is a quick and ef ficient way in innovative mechanical product design. This method economizes mate rial, labor, and time, and then it is the right way of high efficiency and speed to reduce the development period, and increase the quality of product and the r atio of successful development at once.
基金The National Natural Science Foundation of China(No10571026),the Natural Science Foundation of Jiangsu Province(NoBK2005207), the Teaching and Research Award Program for Out-standing Young Teachers in Higher Education Institutions of MOE,PRC
文摘The exchange rings without unity, first introduced by Ara, are further investigated. Some new characterizations and properties of exchange general rings are given. For example, a general ring I is exchange if and only if for any left ideal L of I and a^-= a^-2 ∈I/L, there exists w ∈ r. ureg（I） such that w^- = a^-; E（R, I） （ the ideal extension of a ring R by its ideal I） is an exchange ring if and only if R and I are both exchange. Furthermore, it is presented that if I is a two-sided ideal of a unital ring R and I is an exchange general ring, then every central element of I is a clean element in 1.
