摘要：为了满足航天关键件的加工精度要求,需要设计并制造满足设计要求的纳米级精度的竖直液体静压滑台。本文针对滑台结构、关键部件及公差设计方法展开了研究。首先,根据高精度竖直滑台的设计要求,采用不等流量的滑块结构及控制方法整体设计滑台结构。设计时,将所有液压油管路均设置在滑块中,以减小油压损耗,且使得滑台结构紧凑。接着,为使圆孔加工时圆度误差不受导轨刚度的影响,采用等导轨刚度的设计方法,同时给出了该方法下油膜厚度、刚度、压力的计算方法。文中还证明了上下油腔不等承载面积法能够降低竖直滑台由于倾覆力矩产生的倾角误差,提高导轨运动精度。在此基础上,提出了基于不等流量结构的几何精度设计方法,计算并证明了不等流量的结构和控制方法可以降低导轨和滑块极高的制造等级要求和制造成本。最后,根据上述设计方法设计并制造了数控纳米曲面磨床竖直滑台,并测试了该磨床竖直Z滑台的运动精度。结果显示采用不等流量结构的滑台制造公差要求由IT1降低到IT3。Z滑台精度测试结果为:定位误差为±80nm,重复定位误差为48nm。

摘要：利用***和***关于插值性的刻画,证明了不存在具有3个生成元且满足插值性的小波紧框架.在满足近似插值性及较高阶消失矩的性质下,设计一个低通滤波器,利用不等式得到3个滤波器,从而得到小波紧框架.所得的高通滤波器中有一个满足对称性,一个满足反对称性.设计所得到的滤波器都含有一个自由参数,此参数的引入增加了小波框架的选择余地.

摘要：针对跨声速风扇动叶中掠、弯结合叶片基于控制点的B样条曲线对积叠线进行参数化,以掠、弯为设计自由度,应用实验设计、三维粘性流场求解、响应面模型及遗传算法对Rotor 67以近尖峰效率工况点为设计点对风扇转子进行了气动优化设计,得到了前掠与弯向旋转方向的复合设计叶片,其总压比有较明显提高。但由于优化是在单一工况点下进行的,其变工况性能不佳。

摘要：In actual production,deep coal mine roadways are often under typical static-dynamic coupling stress(SDCS)conditions with high ground stress and strong dynamic *** the increasing number of disasters and accidents induced by SDCS conditions,the safe and efficient production of coal mines is seriously ***,it is of great practical significance to study the deformation and failure characteristics of the roadway surrounding rock under *** this paper,the effects of different in-situ stress fields and dynamic load conditions on the surrounding rock are studied by numerical simulations,and the deformation and failure characteristics are *** to the simulation results,the horizontal stress,vertical stress and dynamic disturbance have a positive correlation with the plastic failure of the surrounding *** these factors,the influence of the dynamic disturbance is the most *** the same stress conditions,the extents of deformation and plastic failure of the roof and ribs are always greater than those of the *** effect of horizontal stresses on the roadway deformation is more notable than that of vertical *** results indicate that for the roadway under high-stress conditions,the in-situ stress test must be strengthened *** determining the magnitude of the in-situ stress,the location of the roadway should be reasonably arranged in the design to optimize the mining *** roadways that are strongly disturbed by dynamic loads,rock supports(rebar/cable bolts,steel set etc.)that are capable of maintaining their effectiveness without failure after certain dynamic loads are *** results of this study contribute to understanding the characteristics of the roadway deformation and failure under SDCS,and can be used to provide a basis for the support design and optimization under similar geological and geotechnical circumstances.

摘要：The bimetallic nanostructures that mix a plasmonic metal with a transition metal in the form of the core-shell nanoparticles are promising to promote catalytic *** it is still unclear how the heat(hot electrons and phonons)transfers on the interface between two *** have designed and synthesized Au@Cu bimetallic nanoparticles with Au as core and Cu as *** using transient absorption spectroscopy,we find that there are two plasmon induced heat funneling processes from Au core to Cu *** is the electron temperature equilibrium(electron heat transfer)with equilibration time of~560 *** other is the lattice temperature equilibrium(lattice heat transfer)with equilibration time of~13 *** plasmon induced heat funneling may be universal in similar bimetallic nanostructures,so our finding could contribute to further understanding the catalytic mechanism of bimetallic plasmonic photothermal catalysis.

摘要：在无线传感器网络的应用中,对无线链路质量进行有效地评估和预测是网络协议设计中的一个基础性问题,特别是对于提高数据的传输可靠性.从刻画无线链路质量的多维角度出发,基于模糊逻辑设计了一个综合性链路质量指标(fuzzy-logic based link quality index,Fli),体现了无线链路的可靠性、波动性和丢包突发性对于链路数据传输可靠性的影响.然后基于Fli准则,利用贝叶斯网络设计了一种对无线链路质量进行分类预测的机制.通过3个实际无线传感器网络研究平台的链路数据集进行实验分析和对比,该机制中的分类预测器的平均预测精度约为85%.相比于4C预测器,在保证平均预测精度的同时,克服了其预测精度在分类界限处的畸变下滑现象,使预测精度的分布均匀化.

摘要：针对制鞋企业鞋楦设计和数据管理的难点及需求,分析了鞋楦数据库系统功能需求,对各类楦体数据进行规范化处理,设计数据库系统结构。以Visual FoxPro 9.0数据库软件为工具,开发了具有人机交互功能的鞋楦数据库系统,能够进行数据检索和维护(增加、删除、修改),实现了鞋楦数据的数字化和规范化管理。该数据库系统可以提高楦型数据检索的工作效率,为企业鞋楦设计和数据管理提供了更为科学有效的手段,同时提高企业的技术知识管理水平。

摘要：民族文化是民族发展的根系,是一个国家延续、生存的根系。如何把民族文化元素融入机电类创意产品设计是促进民族文化发扬光大一个好的方法,现在中国民族元素在世界较为流行,将民族文化元素融入到产品设计中,可以使我们的产品更具有民族特色,更具代表性。

摘要：将碳纳米管吸波剂超声分散到环氧树脂中,制备了碳纳米管/环氧树脂吸波材料。采用同轴法测试了2%、5%、9%(质量分数)碳纳米管/环氧树脂吸波材料电磁参数。随碳纳米管含量的增加,吸波材料的复介电常数不断增大。遗传算法优化设计的介电梯度碳纳米管/环氧树脂吸波材料最优结构为双层5%、9%(质量分数)碳纳米管/环氧树脂复合材料,其厚度分别为0.5146、1.3255mm,多层吸波材料反射率<-5dB频带宽最大,为8.48GHz。

摘要：建立了发动机电子节气门的非线性运动模型,并运用变结构滑模控制理论进行控制器与观测器设计,仿真及实时硬件在环控制试验结果表明采用变结构控制,能很好地克服系统中的非线性及扰动,迅速地获得预期节气门位置。