基于全数字锁相环的步进电机控制系统

研究步进电机优化控制问题,步进电机控制系统存在着控制功能单一和控制精度不高的缺陷。针对上述问题,提出了一种用全数字锁相环的控制系统设计方案。锁相环能够在较大的频率范围内快速跟踪和锁定输入信号的频率和相位,应用脉冲分配控制器,可提高整个系统的同步性能,增强步进脉冲信号频率的稳定性。采用超高速集成电路硬件描述语言(VHDL)进行电路系统设计,利用计算机仿真技术对该系统进行了仿真验证,并给出了布局布线后时序仿真的结果。仿真结果表明,该系统具有控制灵活、响应速度快、稳定性能好等特点,改进的设计方案可实现对步进电机转速、转向和定位的一体化控制,能够显著提高系统的控制精度,并可应用于其它不同工作方式的步进电机控制系统设计。     

PSONN在可编程控制系统PID参数优化中的应用

研究可编程控制系统优化问题,可编程控制系统具有非线性、时变性等特点,传统PID控制器优化方法难以建立精确的数学模型,使得系统参数设定困难,导致可编程控制系统的控制效果不理想。为了解决传统的PID算法所带来的问题,利用RBF神经网络非线性、自学习能力,提出一种基于粒子群神经网络的PID参数优化算法。将粒子群和神经网络相结合,形成了一种智能控制算法,并将应用于可编程控制系统。测试结果表明,粒子群神经网络提高了PID控制参数优化速度,提高了可编程控制系统可靠性和鲁棒性,具有一定的理论和实用价值。     

基于Android平台的无线WiFi控制方法

提出了一种基于Android手机的无线WiFi控制系统。首先采用嵌入式ARM9为硬件控制模块,手机终端以Android为应用程序的开发,编写了一个手机客户端软件,完成了手机端与控制器端之间的数据传输,实现了手机远程对PWM调速等的控制。系统中Android手机可利用周围无线网络资源与其他设备进行交互并实施控制,不仅为现有智能控制系统提供了新的控制方法,也为实现机器与人的信息交换提供了新的交互手段。     

The T Cell Repertoires from Nickel Sensitized Joint Implant Failure Patients

Nickel (Ni²⁺) is one of the most common allergens, affecting around 10–15% of the general population. As the demand for orthopedic implant surgery rises, the number of surgical revisions due to joint implant failure also increases. There is evidence that some patients develop joint failure due to an immune response to a component of the implant, and we have found that Ni²⁺ is an especially important cause. Hence, understanding the mechanisms by which Ni²⁺ allergy induces joint implant failure becomes a critical research question. The structural basis of Ni²⁺ activation of pathogenic T cells is still not clear. The purpose of this study was to characterize Ni²⁺-reactive T cell repertoires derived from the peripheral blood of joint failure patients due to Ni²⁺ sensitization using single-cell sequencing techniques. We stimulated the proliferation of Ni²⁺ -reactive T cells from two implant failure patients in vitro, and sorted them for single-cell VDJ sequencing (10× genomics). We identified 2650 productive V-J spanning pairs. Both TCR α chains and β chains were enriched. TRBV18 usage is the highest in the P7 CD4+ population (18.1%), and TRBV5-1 usage is the highest in the P7 CD8+ population (12.1%). TRBV19 and TRBV20-1 segments are present in a high percentage of both P7 and P9 sequenced T cells. Remarkably, the alpha and beta chain combination of TRAV41-TRBV18 accounts for 13.5% of the CD4+ population of P7 patient. Compared to current Ni specific T cell repertoire studies of contact dermatitis, the Vα and Vβ usages of these joint implant failure patients were different. This could be due to the different availability of self-peptides in these two different tissues. However, TRBV19 (Vβ17) was among frequently used TCR β chains, which are common in previous reports. This implies that some pathogenic T cells could be similar in Ni²⁺ hypersensitivities in skin and joints. The alignment of the TCR CDR3β sequences showed a conserved glutamic acid (Glu) that could potentially interact with Ni²⁺. The study of these Ni²⁺ specific TCRs may shed light on the molecular mechanism of T cell activation by low molecular weight chemical haptens.     

基于边缘提取的图像拼接

对车牌识别系统中的图像拼接问题进行了研究,提出了一种基于边缘提取的图像拼接算法.实验结果证明,该算法获得了理想的拼接效果.     

一种高动态范围图像可视化算法*

提出的自适应HDR图像可视化算法中,输入图像被分解为基本层和细节层.该算法将整体明暗效果的显示看做整体问题,对表示亮度的基本层采用基于整体统计信息的直方图调整算法处理;可视细节信息的保持作为局部问题,算法采用自适应细节增强算法处理细节层.通过定义映射图对细节增强后的图像进行最终映射,将两方面结合起来得到最终结果.实验结果表明,该算法能对HDR图像进行较高视觉质量的显示.     

Copper Assisted Inverted Pyramids Texturization of Monocrystalline Silicon in a Nitrogen Bubbling Bath for Highly Efficient Light Trapping

Silicon - Inverted pyramid (IP) texturization on silicon wafers has recently attracted attention for the structure’s light trapping ability and low specific surface area. The later property...     

AN INVESTIGATION OF QUASI-CLEAVAGE FRACTURE IN STEEL

本文试图探讨准解理断裂的本质。联系多晶材料的典型应力一应变曲线,对不同钢的断裂韧度试样的断口分析表明,准解理断裂可以看作是一种过渡的断裂机制。首先,一系列微观解理裂纹在高拉伸应力集中地方生核,然后这些裂纹各自沿着它本身已变形晶粒的解理面上扩展,最后借助于微观塑性聚合方式,这些微裂纹彼此连接。根据上述断裂模型可以认为:解理裂纹与塑性变形间的相互作用是准解理断裂的一种重要性质。借助于断口定量分析方法,有可能把断口形貌和一些力学参数间关系建立起来。     

基于LabVIEW软件的虚拟数字超声探伤仪设计

传统的仪器一般开发周期较长,分析测试的精度低、成本高。虚拟仪器是利用计算机显示器的显示功能来模拟传统仪器的控制面板,以多种形式输出检测结果;利用软件功能实现数字信号的运算、分析和处理;利用输入/输出(I/O)接口设备完成信号的采集、测量与调试,从而完成各种测试功能的一种计算机仪器系统。采用LabVIEW应用软件对数字式超声探伤仪面板和部分功能进行设计与构建,并实现其相关功能。     

Nd_2(Fe_(0.9)Si_(0.1))_(14)B的中子衍射研究SCIEI

本文用中子衍射对Nd_2(Fe_(0.9)Si_(0.1))_(14)B在室温及77K进行了测量,用衍射峰的形状分析法进行了数据拟合。结果表明,在室温,Si择优占据4c,8j_1及16k_2晶位;Nd与Fe的磁矩平行于C轴排列。在77K,Si仍择优占据上述三个晶位。算得的Nd磁矩的方向偏离C轴37.8°。