为提高乘客舒适度,利用调谐质量阻尼器(tuned mass damper,TMD)对100 m X-BOW型极地探险邮轮的局部振动进行控制。建立邮轮的有限元模型,进行整船频响分析,通过比较仿真值与测试值间的误差,验证模型的有效性。根据整体模态等价质量求解...为提高乘客舒适度,利用调谐质量阻尼器(tuned mass damper,TMD)对100 m X-BOW型极地探险邮轮的局部振动进行控制。建立邮轮的有限元模型,进行整船频响分析,通过比较仿真值与测试值间的误差,验证模型的有效性。根据整体模态等价质量求解方法和局部模态质量的空间分布原则,提出混合模态中单个局部模态等价质量的求解方法,利用该方法求解邮轮局部振动区域的等价质量;利用该等价质量计算TMD的质量比;基于该质量比,求解出对应的TMD参数最优解。通过分析可知,当质量比为0.05时,TMD在13.4 Hz处具有31 dB的吸振效果,同时在10 Hz和18.8 Hz处也有一定的吸振效果,分别为3 dB和2 dB,整体控制频段较平坦,鲁棒性也较佳。展开更多
With the increasing requirement for the protection of arable land, monitor- ing the grades of arable land quality is becoming more important, which can accu- rately and fully reflect the current situation and developm...With the increasing requirement for the protection of arable land, monitor- ing the grades of arable land quality is becoming more important, which can accu- rately and fully reflect the current situation and development trends of arable land quality. It is also an important measure for protecting the quality of arable land. in the present study, the distribution and changes of arable lands of different gradient types and grades in Lingchuan County, Guangxi Zhuang Autonomous Region in 2015 were monitored and evaluated, to analyze the trends and reasons for the changes in the quality and productivity of arable lands, and to provide references for dynamic monitoring of the quality of arable land.展开更多
Recently, the scale of higher education for adults is expanding and at the same time, the teaching quality is declining, which has been increasingly focused on. In order to improve the teaching quality, at first, it i...Recently, the scale of higher education for adults is expanding and at the same time, the teaching quality is declining, which has been increasingly focused on. In order to improve the teaching quality, at first, it is necessary to build up a set of integrative and complete teaching quality evaluation system, which is composed of class, course major and college respectively from the aspects of learning and teaching because of the particularity of the students and teaching modes of higher education for adults.展开更多
文摘With the increasing requirement for the protection of arable land, monitor- ing the grades of arable land quality is becoming more important, which can accu- rately and fully reflect the current situation and development trends of arable land quality. It is also an important measure for protecting the quality of arable land. in the present study, the distribution and changes of arable lands of different gradient types and grades in Lingchuan County, Guangxi Zhuang Autonomous Region in 2015 were monitored and evaluated, to analyze the trends and reasons for the changes in the quality and productivity of arable lands, and to provide references for dynamic monitoring of the quality of arable land.
文摘Recently, the scale of higher education for adults is expanding and at the same time, the teaching quality is declining, which has been increasingly focused on. In order to improve the teaching quality, at first, it is necessary to build up a set of integrative and complete teaching quality evaluation system, which is composed of class, course major and college respectively from the aspects of learning and teaching because of the particularity of the students and teaching modes of higher education for adults.
