Aiming at the discontinuous traction on contact elements of roller bearing,new concepts of sub- and micro-element are put forward. In the sub-element and micro-element,traction influence coefficient has been modified,...Aiming at the discontinuous traction on contact elements of roller bearing,new concepts of sub- and micro-element are put forward. In the sub-element and micro-element,traction influence coefficient has been modified, which is calculated by the former boundary elementmethod (BEM) with roller bearing load. Hence, three-dimensional distribution of load on rollerbearing is calculated accurately. In practice, it has been proved that this method has highercalculation accuracy. An effective numerical method is offered for analyzing load characteristics ofroller bearing to improve service longevity of roller bearing and operation efficiency of rollingmill.展开更多
To study the effect of cultivation system （conventional and organic） on potato tuber components, 42 parameters （anti-nutritives, micro- and macro-elements and 23 metabolites） were studied in three multi-resistant ...To study the effect of cultivation system （conventional and organic） on potato tuber components, 42 parameters （anti-nutritives, micro- and macro-elements and 23 metabolites） were studied in three multi-resistant Hungarian potato varieties for three years in 2007-2009. Discriminant analysis of data proved that all investigated factors （farming technology, genotype and season/year） had significant effect on metabolites. Reversed phase high performance liquid chromatographic （HPLC-DAD, HPLC-MS） and elemental analysis methods have been adapted to quantify the major components, i.e., steroidal alkaloids, nitrite, nitrate, sugars, amino acids and micro-elements, in potato tubers. The absolute amount and changes of tuber components were influenced differentially by the technology, genotype and season in a complex manner. Any examined component, except nitrate content, was found to be significantly higher or lower consistently in relation to the production practice （organic or conventional） during the three years trials. Under the examined circumstances, no consequent positive effect of organic fanning on the total amount of anti-nutritive components, vitamins or micro- and macro-elements of potato tubers could be proven.展开更多
区别于传统磁轴承,屏蔽式主动磁轴承(canned active magnetic bearing,CAMB)在定子内表面和转子外表面分别包覆了一层不导磁不锈钢屏蔽套,从而可以工作于腐蚀性液体等恶劣环境。由于转子旋转及电流纹波造成的磁通变化在定子屏蔽套和转...区别于传统磁轴承,屏蔽式主动磁轴承(canned active magnetic bearing,CAMB)在定子内表面和转子外表面分别包覆了一层不导磁不锈钢屏蔽套,从而可以工作于腐蚀性液体等恶劣环境。由于转子旋转及电流纹波造成的磁通变化在定子屏蔽套和转子屏蔽套中造成了额外的涡流损耗。提出了一种采用微元法和谐波分离计算屏蔽套损耗的计算模型,解析磁通量的恒定分量和谐波在屏蔽套中产生涡流的机理并分别计算涡流损耗大小,根据端部涡流路径对屏蔽套损耗模型进行了修正。同时计算了常规铜损、铁损和风摩损耗。搭建了CAMB的损耗测试实验平台,并设计了相关的损耗分离实验,验证了所提出模型的准确性。展开更多
基金This project is supported by National Natural Science Foundation of China (No.50205004, No. 50075075).
文摘Aiming at the discontinuous traction on contact elements of roller bearing,new concepts of sub- and micro-element are put forward. In the sub-element and micro-element,traction influence coefficient has been modified, which is calculated by the former boundary elementmethod (BEM) with roller bearing load. Hence, three-dimensional distribution of load on rollerbearing is calculated accurately. In practice, it has been proved that this method has highercalculation accuracy. An effective numerical method is offered for analyzing load characteristics ofroller bearing to improve service longevity of roller bearing and operation efficiency of rollingmill.
文摘To study the effect of cultivation system （conventional and organic） on potato tuber components, 42 parameters （anti-nutritives, micro- and macro-elements and 23 metabolites） were studied in three multi-resistant Hungarian potato varieties for three years in 2007-2009. Discriminant analysis of data proved that all investigated factors （farming technology, genotype and season/year） had significant effect on metabolites. Reversed phase high performance liquid chromatographic （HPLC-DAD, HPLC-MS） and elemental analysis methods have been adapted to quantify the major components, i.e., steroidal alkaloids, nitrite, nitrate, sugars, amino acids and micro-elements, in potato tubers. The absolute amount and changes of tuber components were influenced differentially by the technology, genotype and season in a complex manner. Any examined component, except nitrate content, was found to be significantly higher or lower consistently in relation to the production practice （organic or conventional） during the three years trials. Under the examined circumstances, no consequent positive effect of organic fanning on the total amount of anti-nutritive components, vitamins or micro- and macro-elements of potato tubers could be proven.
文摘区别于传统磁轴承,屏蔽式主动磁轴承(canned active magnetic bearing,CAMB)在定子内表面和转子外表面分别包覆了一层不导磁不锈钢屏蔽套,从而可以工作于腐蚀性液体等恶劣环境。由于转子旋转及电流纹波造成的磁通变化在定子屏蔽套和转子屏蔽套中造成了额外的涡流损耗。提出了一种采用微元法和谐波分离计算屏蔽套损耗的计算模型,解析磁通量的恒定分量和谐波在屏蔽套中产生涡流的机理并分别计算涡流损耗大小,根据端部涡流路径对屏蔽套损耗模型进行了修正。同时计算了常规铜损、铁损和风摩损耗。搭建了CAMB的损耗测试实验平台,并设计了相关的损耗分离实验,验证了所提出模型的准确性。
