A hybrid drive of underwater robot which can be folded propeller device

本发明属于水下机器人领域，具体地说是一种混合驱动水下机器人用可折叠螺旋桨装置，包括艉部导流罩、电机、联轴器、螺旋桨轴、桨毂及桨叶，电机安装在艉部导流罩内，输出端通过联轴器与螺旋桨轴的一端连接、驱动螺旋桨轴旋转，螺旋桨轴的另一端由艉部导流罩穿出、与桨毂相连；桨毂上安装有多根桨叶轴，每根桨叶轴上均转动连接有桨叶，每根桨叶轴上均套设有扭转弹簧，扭转弹簧的两端分别与桨毂及桨叶相连；各桨叶随桨毂由螺旋桨轴带动旋转，通过离心力展开产生推力，展开的、停止旋转的桨叶通过扭转弹簧复位。本发明具有可靠性高、机械结构紧凑、运动方式简单、重量轻、成本低、运输安全、便于装配及维护等优点

Vibration reduction optimization of gear modification based on Kriging model and genetic algorithm

针对齿轮修形优化时计算啮合刚度计算量大、计算精度低、操作繁琐等问题,提出一种基于Kriging模型和遗传算法的齿轮减振修形优化算法.以典型直齿轮传动为例开展齿轮修形优化,通过拉丁抽样建立Kriging模型,解决齿轮修形优化的多响应和隐式函数的问题,通过Kriging预测的啮合刚度与有限元法的对比可知,时变啮合刚度函数各参数的误差最大值为7.79×10~(-5),1.20×10~(-3)及1.30×10~(-4),验证了Kriging多响应预测啮合刚度函数的精确性.将Kriging预测函数代入直齿轮啮合传动的动力学微分方程,采用遗传优化算法时将齿轮动态传动误差响应波动最小作为优化目标,得到最优的..

a genetic algorithm based on common path for tsp

遗传算法是一种解决TSP问题的有效算法。文章提出了一种基于路径共同顺序的新型遗传操作方法,即首先寻找父辈的共有路径信息,然后构建后代,该方法缩小了搜索优解的范围,加快了优化过程的收敛速度。在此基础上针对TSP实例,实现了基于共同顺序的优化方法来解决小规模TSP问题,以及更有效的基于共同顺序的循环优化方法来解决大规模TSP问题。实验结果验证了该方法的有效性

Development of high Al content structural Ⅲ nitrides and their applications in deep UV-LED

随着高gA组分Ⅲ族氮化物相关研究的日趋深入和生长技术的日益成熟,人们逐渐将研究重心转向具有更宽带隙的高Al组分Ⅲ族氮化物。该材料常温下带隙宽至6.2 EV,可覆盖短至210 nM的深紫外波长范围,具有耐高温、抗辐射、波长易调控等独特优点,因而是制备紫外发光器件的理想材料。目前,高Al组分Ⅲ族氮化物材料质量不高,所制备的深紫外lEd发光器件仍存在内量子效率、载流子注入效率和沿C轴方向正面出光效率较低的难题,因而制约了高效紫外发光器件的制备。本文着重介绍了近年来在高Al组分Ⅲ族氮化物生长动力学方面的研究进展,总结和梳理了量子结构设计、内电场调控以及晶体场调控等方面的相关研究,以期实现高质量深紫外lEd的制备。Along with the extensive investigations and growth technology maturation on high Ga content III-nitrides,researchers have moved their focus onto high Al content III-nitrides.Given a wider band gap up to 6.2 eV at room temperature,covering UV-light area as short as 210 nm,as well as other advantages of III-nitrides,high Al content III-nitrides are ideal materials for the fabrication of UV-light emitting devices.At present,there are certain challenges in the fabrication of UV-light emitting devices with high internal quantum efficiency,carrier injection efficiency and light-extraction efficiency due to the low quality materials.In this work,the progress on growth kinetics of high Al content III-nitrides in recent years has been reviewed comprehensively,and the corresponding researches in quantum structure design,internal electric field modification and crystalline field modification have been overviewed and analyzed.This review is expected to be informative for the fabrication of deep UV-LEDs.“973”规划项目(2012CB619301、2011CB25600); “863”计划项目(2011AA03A111); 国家自然科学基金项目(61227009、90921002); 中央高校基本科研业务费专项资金资助项目(2012121014、CXB2011029); 福建省自然科学基金计划项目(2012J01024

湖北臭氧分布特征及其管控措施

采用地面站点观测、卫星观测以及UWCM 0-D箱子模型模拟的方法研究湖北2013—2015年臭氧时空分布特征,并探讨其管控措施。从地面站点观测看出,时间分布上,这3年臭氧年平均浓度经历先下降后上升的过程,总体呈上升趋势,而二氧化氮年平均浓度则呈现持续下降的趋势;空间分布上,湖北各区域臭氧浓度分布不均匀,呈现东高西低的递减分布趋势。从卫星观测数据看出,2015年湖北的臭氧柱浓度高于2013、2014年同期。从空间分布来看,臭氧的柱浓度是从东北到西南、从省外到省内逐渐递减,因此推测,除了本地生成,湖北的臭氧有一部分是来源于省外传输。最大臭氧生成量法显示,烯烃(乙烯和丙烯)对湖北夏天臭氧生成量的贡献远大于其他挥发性有机化合物。箱子模型模拟的结果显示,湖北应该通过控制挥发性有机化合物的排放来降低臭氧生成速率,控制氮氧化物反而使臭氧生成速率提高。 Ground site observation,satellite observation and UWCM 0-D box model simulation were used to study the spatial and temporal distribution of ozone in Hubei during 2013-2015,and then its control measures were examined. From the data in observation stations,the annual average concentration of ozone decreased in 2014 and then increased in 2015 when compared to that in 2013. In contrast,the annual average concentrations of the nitrogen dioxide showed a decreasing trend during these three years. The spatial distribution of the ozone concentrations in Hubei is uneven,with a trend of decreasing distribution from east to west. Seen from the satellite observations,ozone column concentration in 2015 is higher than that in 2013 and 2014. Spatial distribution indicates that ozone column concentrations gradually decreased from northeast to southwest,from outside to inside of the province,which suggests that in addition to local generation,part of ozone in Hubei came from the regional transport.According to the method of maximum ozone formation,olefins( ethylene and propylene) contributed more ozone generation in summer than other VOCs( volatile organic compounds). The box model simulation results showed that Hubei should control the emission of VOCs to reduce the ozone production,while controlling the nitrogen oxide would raise the ozone generation rate