输入非线性方程误差系统的多新息辨识方法

针对输入非线性方程误差系统,即输入非线性受控自回归系统,研究了基于过参数化模型的多新息辨识方法和基于过参数化模型的递阶多新息辨识方法;研究了基于关键项分离原理的多新息辨识方法;使用辨识模型分解技术,研究了基于关键项分离原理的两阶段多新息辨识方法和三阶段多新息辨识方法.这些方法可以推广到其他输入非线性方程误差系统、输入非线性输出误差类系统、输出非线性方程误差类系统、输出非线性输出类系统、反馈非线性系统等.同时,给出了几个典型辨识算法的计算量、计算步骤和流程图.     

Effects of different CdCl<Subscript>2</Subscript> annealing methods on the performance of CdS/CdTe polycrystalline thin film solar cells

In this paper, the effects of different CdCl₂ annealing methods, including vapor annealing and dip-coating annealing, on the performance of CdS/CdTe polycrystalline thin-film solar cells are studied. After annealing, the samples are lightly etched with 1% bromine in methanol to remove surface oxides. Both annealing methods give CdTe polycrystalline thin films with good crystallinity and complete structure. For solar cells containing the annealed CdTe films, cell efficiency first increases and then decreases as the concentration of CdCl₂ solution used for dip-coating annealing increases, and the optimized CdCl₂ concentration is 12%. The uniformity of the performance of all cells is analyzed by calculating the relative standard deviation for each parameter. The uniformity of cell performance can be improved dramatically by dip-coating annealing instead of vapor annealing. Most notably, an appropriate concentration of CdCl₂ (12%) acts as a protective layer that is conducive to realizing uniform high-performance CdS/CdTe solar cells. According to the location of depletion regions, the CdTe films treated by dip-coating annealing show a relatively low doping concentration, except for the sample treated with a CdCl₂ concentration of 6%, which is consistent with the changes of short-circuit current density of the cells. It is believed that these results can be applied to the large-scale production of CdTe polycrystalline thin-film solar cells.     

ZigBee无线传感器网络测试平台研究

针对无线传感器网络测试技术标准尚在研究发展之中而无法建立统一测试平台的状况,设计了一种基于ZigBee／IEEE802．15．4标准,以CC2530为控制器的无线传感器网络测试平台,并对无线传感器网络的相关内容进行测试,为无线传感器网络的实际工程应用测试提供了一定借鉴。     

Hot deformation behavior of low carbon steel during compression at elevated temperature

Hot compression tests of low carbon steel were carried out on Gleeble-3500 system in the temperature range from 750 to 900 ℃ and in the strain rate range from 0.001 to 1.0 s-1, and the associated microstructural evolution was studied by observations with a metallographic microscope. The results show that the stress-strain curves exhibit a peak stress at critical strain, after which the fl ow stresses decrease monotonically until reaching high strains, showing a dynamic fl ow softening. The peak stress level decreases with increasing deformation temperature and decreasing strain rate, which can be represented by the Zener-Hollomon parameter Z in the hyperbolic sine equation. The fl ow stress increases with increasing strain rate and decreasing deforming temperature. The fl ow stress can be described by constitutive equation in hyperbolic sine function and can also be described by a Zener–Hollomon parameter Z. With increasing deformation temperature and decreasing strain rate, the grain size as well as the volume fraction of the recrystallized grains increase. The safe region for hot working of the alloy has been determined according to the processing map and microstructure at the true strain of 0.5, which is the deformation temperature of 840-940 ℃ and the strain rate of 0.001-1.0 s-1.     

低功耗双模态电子货架标签系统

为取代传统的纸质货架标签,提出一种低功耗的双模态电子货架标签系统。该系统基于物联网和无线传感器网络技术,针对低功耗目标,采用电泳式电子纸与蓝牙模块分别作为显示与通信模块。并将标签的运行状态分为工作与休眠两种状态,使其按照服务器指令按时切换运行状态,在满足低功耗的前提下实现标签状态汇报、内容更新等功能。从实验数据可见,该系统能基本满足应用场合的功能需求,相对传统的纸质标签具有明显的营运成本优势。     

基于Costas编码脉冲串的低截获声呐波形设计方法

针对声呐低截获波形设计,提出了一种基于有限域理论的Costas编码脉冲串跳频信号构建方法。该方法根据整数集合生成有限域的充分性定理和有限域中本原元的存在性定理,在给定素数p的条件下,构造了包含p个元素的有限域,给出了该有限域中本原元的求解方法以及递推公式,该方法可以通过大数值模除运算来构造高阶次Costas阵列。实验结果表明,基于有限域理论的Costas编码脉冲串跳频信号具有较小的非循环互相关系数和"图钉"状的模糊度函数,具有好的多普勒频率分辨率和时延分辨率,对于低截获声呐设计具有重要的实用价值。     

青岛市即墨鳌山卫镇的历史文化资源保护策略

在城市化快速发展的今天,很多普通小城镇的历史文化被漠视,城镇建设缺少地方特色,造成人文资源、自然资源的破坏.在鳌山卫镇快速建设的今天,亟待一套完整、科学的历史文化保护策略,以缓解城镇历史文化的延续与新城镇建设之间的矛盾,实现城镇建设的可持续发展.     

双向飞翼超声速客机激波阻力和声爆研究

基于超声速双向飞翼构型,采用CFD方法进行阻力计算,采用F-BOOM程序进行声爆计算,研究翼型、平面形状和EFCE激波阻力优化算法对双向飞翼激波阻力和声爆的影响。计算结果表明,平底构型可以明显降低双向飞翼超声速客机的超声速巡航的声爆,却很大程度上增加了巡航阻力,而对称构型却恰好相反;细长的平面几何形状对降低双向飞翼激波阻力和声爆都有作用,尤其对降低对称构型的声爆效果明显;EFCE激波阻力优化算法对降低双向飞翼激波阻力有明显作用,但同时会带来声爆方面的不利影响。因此,超声速客机的减阻设计和低声爆设计需要进行权衡研究。     

积分约束下的追逐微分博弈

考虑二维空间中多人追逐一人逃逸的简单运动的追逐微分博弈,首先对参与者的控制函数强加上了积分约束的条件,然后明确提出了可容许的追逐策略来得到追逐完备的充分条件。     

室温固相法制备纳米Fe_2O_3的工艺研究

以FeCl3·6H2O和NaOH为原料,Tw een-80为分散剂,在室温下通过固相反应制备前驱物,然后煅烧前驱物制得纳米氧化铁。研究了表面活性剂的用量、前驱物的煅烧温度、煅烧时间对产物的影响。利用XRD对制备的纳米氧化物进行表征。结果表明,制备的产物为纳米α-Fe2O3。表面活性剂Tween-80可使产物的产率明显提高,粒径减小;随煅烧温度的提高,煅烧时间的延长,产物的粒径先减小,再增大。煅烧温度500℃,煅烧时间2h,制得的α-Fe2O3的平均粒径为21nm。