基于数字技术创建交互式实验教学资源的实践与探索

在“互联网+”的时代背景下,数字化展览馆正成为一种文化趋势。作为建筑大类教学的重点实践环节,建筑模型的制作、展示和存储具备艺术价值和学习交流的双重意义。为了打破时空界限,整合教学资源,基于三维扫描、网络交互等数字技术,领先于国内建筑类高校,创建了学生数字化虚拟建筑模型展览馆,探讨并实践了实体建筑模型数据采集、数字化建模数据匹配、全数据处理流程、虚拟平台全息展示、在线网络交互等一系列现实资料虚拟化应用的技术,提出了一套系统完整的数字化建筑模型在线展示的流程。     

长线列红外探测器双模式成像装置中的摆镜控制系统设计

为了实现长线列红外探测器双模式成像装置的两种工作模式,需要在成像装置中增加摆镜控制系统,而高速扫描时的扫描线性度和静止时的位置稳定精度是本系统设计的关键因素.本文着重论述了摆镜控制系统的整体设计和指标要求,基于这些指标,提出了一种高线性和高稳定精度摆镜控制系统的实现方案.并利用Simulink进行了仿真,验证该方案切实可行.     

Simulation of Crack Growth in FRP Reinforced Concrete

Experimental results show that the crack growth of fiber-reinforced polymer (FRP) reinforced concrete flexural elements experience a crack development stage followed by crack stabilization. The crack length and elastic crack mouth opening displacement (CMOD) increase during the crack development stage until reaching the crack stabilization stage. A finite-element representation was proposed to predict the initial CMOD. A debonded length was specified to account for the bond-slip between FRP bar and concrete. It was assumed that there was no tangential displacement between the reinforcement and concrete outside of the debonded length. A fatigue model was created using the Paris equation to simulate the growth of elastic CMOD. The model displayed good agreement with the test results. A size effect was also observed for the exponential parameter in the Paris equation.     

Temperature rating prediction of Tibetan robe ensemble based on different wearing ways

Each piece of Western clothing has a unique temperature rating (TR); however, based on different wearing ways, one Tibetan robe ensemble can be used in various environments of the Tibetan plateau. To explain this environmental adaptation, thermal insulations and TR values of Tibetan robe ensembles in three typical wearing ways were measured by manikin testing and wearing trials, respectively. The TR prediction models for Tibetan robe ensembles were built in this research. The results showed that the thermal insulations of Tibetan robe ensembles changed from 0.26 clo to 0.91 clo; the corresponding TRs ranged from 9.90 °C to 16.86 °C because of different wearing ways. Not only the thermal insulation, but also the ways of wearing Tibetan robes was important to determining their TR values. The three TR models and a triangle area for each piece of Tibetan clothing explained its positive adaptation into the environment; this was different from the current TR models for Western clothing.     

超声波时差法的三维矢量风测量系统

超声波测量水平风的技术已经在地面气象观测业务中应用多年,效果很好。将这种技术稍加变通,将测量的平面三角形结构变成正四面体结构的不相交两边,使之形成具有三维测量能力的特殊结构。采用步进频率测量技术,将发射的100 kHz频段的超声波进行扩频调制,通过相关接收后获得脉冲压缩,兼顾了较低峰值发射功率的接收灵敏度问题,以及超声波脉宽造成的时间测量精度问题,还具有一定的抗干扰能力。仿真和实验室初步实验结果证实了这种方法的可行性。     

保持视觉感知的三维树木叶片模型分治简化方法

三维树木的复杂外观形态和庞大网格数据量使得要实现精细树木模型的快速绘制十分困难.由于叶片信息在三维树木模型数据中占的比重很大,为了减少三维树木模型的数据量,提出一种保持视觉感知效果的三维树木叶片模型分治简化方法.该方法综合考虑了树叶纹理颜色和几何形状的相似性来进行相似树叶的选择与合并,并根据树木的树枝拓扑结构或树叶的空间区域分布来划分树叶简化区域,采用相应的分治策略以加速树叶的合并过程,以实现保持视觉感知特征的三维树木模型的简化.实验结果表明,文中方法能有效地减少树木模型的几何数据量,提高绘制效率,可应用于近景树木的快速逼真绘制.     

δ铁素体含量对Fe-Cr-Ni-Mn-N系不锈钢氢脆敏感性的影响

采用高压气相充氢后进行缺口试样拉伸试验的方法,证实了δ铁素体含量的增加显著提高Fe-Cr-Ni-Mn-N系奥氏体不锈钢的氢脆敏感性.     

永磁直驱风力发电系统最大功率跟踪非线性抗扰控制

针对永磁同步发电机的非线性、内部参数不确定以及外部扰动等问题,提出了一种直驱式永磁同步风力发电系统最大功率跟踪的非线性抗扰控制方法。该方法使用一种非线性光滑函数来设计非线性扩张状态观测器(NLESO)和非线性抗扰控制律。由NLESO来实现系统扰动及不确定性的估计,前馈到控制输入端对扰动进行补偿,从而有效提高了系统的抗扰能力。分析了NLESO的收敛性。仿真结果表明了该控制方法不仅具有响应速度快、控制精度高的特点,而且无超调无抖振现象,因而在风力发电系统最大功率跟踪控制领域具有较大应用价值。     

Development of under water-use humanoid robot

In this research, we daveloped a swimming robot with a fluttering kick of two legs which can swim freely both on the surface of the water and under the water. We have established control methods for all kinds of motion of this robot. We considered a dynamic model with undulating fins, and this has been used to construct a dynamic model of a propulsion and control system, and to analyze its motion velocity and propulsion efficiency. We proposed and designed the corresponding control algorithms to generate an appropriate thrust force and to decrease the disadvantageous influences of the interference of fluttering kicks. We can now realize free posture control and obtain various forms of motion.     

复杂控制系统在多晶硅项目中的应用

概述了多晶硅全厂及其核心生产装置氯化氢合成工序和还原氢化工序的工艺流程。结合复杂控制系统的工作原理,对其中2个典型复杂控制回路的运行设置、使用情况和应注意的问题做了总结,进而体现了多晶硅工艺生产的复杂性。采用该工艺的国内某多晶硅装置一次开车成功,目前运行稳定。结果表明,该工艺方案安全可靠,控制效果和可行性较好,从而为同类多晶硅项目的设计实施提供了借鉴。