TD处理在专用车冷作模具中的应用

通过对专用车冷作模具表面TD处理的研究应用,介绍了TD处理的技术原理、工艺流程、TD处理后的性能及TD处理中的注意事项。实践证明TD处理是改善高强度钢冷作模具的最佳手段之一,可以取得显著的经济效益。     

TD处理技术及其应用

介绍了TD处理技术概况及其应用。TD处理技术是一种先进的表面强化技术，在国外已经得到了普遍的应用。     

TD渗钒处理圆形冲孔凸模抛光工装设计

冲孔凸模磨损是模具失效的主要形式之一。对大规格冲孔凸模应用TD渗钒处理技术,需对TD处理前后冲孔凸模表面进行抛光,自行设计制造了一种多工位的半自动抛光机构。提高抛光效率、质量和安全性。     

TD75型带式输送机尾部小车拉紧装置的改造

广州珠江电厂输煤系统带式输送机原使用了12台TD75型尾部小车拉紧装置 ,实际使用中曾出现较多问题 ,经多次维修处理 ,效果并不理想。将其改造为新型拉紧装置后彻底消除了原使用过程中的问题 ,取得了较好的使用效果。1　TD75型尾部小车拉紧装置的主要问题TD75型尾部小车拉紧装置见图 1。图 1　TD75标准车式拉紧装置由于行走部分采用面接触 ,导轨与行走轮间隙大 ,容易形成上下或左右摆动 ,产生较大阻力 ,小车运行不畅或根本拉不动。过大的阻力使拉紧小车运行时两侧受力不均 ,造成带式输送机跑偏 ,甚至小车翻车 ,导致人员和设备事故 ;小车…     

TD4652型示波器故障与维修

介绍TD4652型超低频双踪示波器的常见故障现象及其产生的原因，给出故障处理方法。     

TD2-A型数字探空仪在高空测报中的应用

根据阜阳高空站2006—2008年应用TD2-A型数字探空仪的经验,在探空仪的放前准备、抓球及跟踪等操作及特殊情况的处理方面,总结出一些行之有效的操作技巧与处理方法。     

数控车床刀架控制系统的故障分析与处理

以实例980TD1系统，4工位电动刀架为例；分析数控系统与刀架的控制原理，通过控制原理分析故障，查看PMC程序，根据诊断画面查找并调整参数，以排除故障.     

ThinkDesign/TD PLM助力全球领先卫浴制造商

日前,多年来一直应用TD系列产品ThinkDesign进行产品设计的意大利著名卫浴设备制造商Zucchetti(舒洁帝)公司宣布,再次选择TD系列产品——TD PLM为企业服     

离子渗氮和离子镀复合处理研究

针对具有特殊高性能要求的齿轮 ,选用 32Cr2MoV钢离子镀陶瓷膜和离子氮化后离子镀陶瓷膜复合表面处理进行了研究 ,对两种工艺处理后的组织进行了观察 ,对其横截面硬度进行了测定 ,分析了陶瓷膜层与基体的结合状况。结果表明 ,复合处理样的硬度较单独处理样有很好的梯度 ,膜层与基体的结合状况好 ,膜层性能优越     

激光表面处理技术的推广应用

本文论述了激光处理技术发展趋势和应用前景，并结合我们近几年的工作情况，说明发动机缸体（套）内壁经激光处理后的性能大幅度提高，报废的石材锯片经激光处理后其使用寿命可达到新锯片的水平，同时阐述了轴类零件经激光相变硬化处理能提高使用寿命２～３倍，轴类零件磨损后能通过激光合金化熔覆技术进行修复     

Histochemical analysis of lymphatic endothelial cells in lymphostasis

The ultrastructure of endothelial cells of intestinal lymphatics and the thoracic duct (TD) and the relation to lymphostasis were examined in rats and monkeys. Localization of 5'-nucleotidase (5'-Nase) and endothelial nitric oxide synthase (eNOS) was studied. In normal lymphatic endothelial cells, 5'-Nase reaction product was evenly deposited on the cell surface in vivo and on cultured TD endothelial cells (TDECs), whereas eNOS was evenly distributed throughout the nucleus and cytoplasm. TDECs had a long filamentous process extending towards the subendothelial extracellular matrix but became flat and regular within 30-40 minutes after gastric perfusion with olive oil. According to their electron-density, two types of cells were found in the TD endothelial layer. The cells with low electron-density exhibited stronger 5'-Nase activity. Valves were bicuspid formations and the valvular endothelial surface of the convex side showed weaker 5'-Nase activity than the concave side. During TD blockage-induced lymphostasis in rats, the 5'-Nase product was almost not discernible in the TDECs within 2 weeks. Larger vesicles were found in the endothelial cytoplasm of the ligated TD. Their number decreased after 6-12 weeks. The small intestinal lymphatics in the mucosa and submucosa were dilated, with numerous open intercellular junctions. The endothelial lining appeared to have reduced activities for 5'-Nase and eNOS in 9 of 11 experimental animals. The results indicated that the inability of the open intercellular junctions, normally working as one-way endothelial flap valves, may be a key morphological feature after TD blockage. Reduced eNOS and 5'-Nase may functionally influence contractile activity and transport capability of the lymphatic vessels in the lymphostasis.     

约束层阻尼梁厚度变形的实验研究

约束层阻尼是减振降噪的一种有效方法,Mead-Markus模型不能解释约束层阻尼梁中黏弹层的相对厚度变形.为解释这种变形,Miles和Reinhall提出TD (thickness deformation)模型.文中通过实验的方法验证TD模型的有效性, 并对这种相对变形进行分析讨论.实验结果显示,相对于Mead-Markus模型,尽管TD模型可能不是一种精确的理想模型,但它适用于更宽的激励频率,并可提高模型的分析精度.     

Formability evaluation of friction stir welded 6111-T4 sheet with respect to joining material direction

In order to evaluate the formability of friction stir welded (FSW) automotive TWB (tailor-welded blank) sheets with respect to base material direction, the aluminum alloy 6111-T4 sheet was joined with three different types of combination: RD||RD, TD||RD, TD||TD (Here, RD and TD mean the rolling direction and transverse direction, respectively). Formability performance was experimentally and numerically studied in three applications including the simple tension tests, hemisphere dome stretching and cylindrical cup drawing tests. For numerical simulations, the non-quadratic orthogonal anisotropic yield function, Yld2004-18p and the isotropic hardening law were implemented into the material constitutive model. As for the failure criterion, the forming limit diagram (FLD) was utilized to determine the failure strain.     

一种新型最优PID控制器的设计

以蚁群算法为基础，提出了一种新的具有不完全微分的最优PID控制器的参数优化策略。该策略通过蚁群算法找出系统的3个最优参数，即比例增益Kp,积分时间常数T1和微分时间常数TD，针对给定的控制对象，给出了新算法的具体实现步骤。仿真应用表明，这种PID控制器具有很强的灵活性、适应性和鲁棒性。     

基于SwanSoft的数控车削仿真加工实践

利用SwanSoft数控仿真软件的功能,完成对一根曲面轴零件在FUNUC-0TD系统中的数控车削仿真加工,旨在探讨仿真加工中经常出现的一些问题及解决办法,并总结出仿真加工的操作技巧。在进行仿真加工前,先做了零件图分析、加工工艺分析、程序的手工编写等,然后在Word中将录入的程序预先转存为.CNC文件供软件导入调用,用手工试切对刀的方法并在对刀时对刀具移动速度实施快中慢三段控制。通过实践验证,注重技巧有助于提高仿真操作的效率。     

基于TD400C的压缩机控制系统的组态设计

主要阐述了基于S7 -200PLC及TD400C文本显示器的压缩机自控系统的组态设计.系统以S7200PLC作为核心控制单元,配合TD400C实现对压缩机工作的实时监控.     

High-precision tracking differentiator via generalized discrete-time optimal control

An enhanced discrete-time tracking differentiator (TD) with high precision based on discrete-time optimal control (DTOC) law is proposed. This law takes the form of state feedback for a double-integral system that adopts the Isochronic Region approach. There, the control signal sequence is determined by a linearized criterion based on the position of the initial state point on the phase plane. The proposed control law can be easily extended to the TD design problem by combining the first-state variable of the double-integral system with the desired trajectory. To improve the precision of the discretization model, we introduced a zero-order hold on the control signal. We also discuss the general form of DTOC law by analysing the relationship between boundary transformations and boundary characteristic points. After comparing the simulation results from three different TDs, we determined that this new TD achieves better performance and higher precision in signal-tracking filtering and differentiation acquisition than do existing TDs. Also the comparisons of the computational complexities between the proposed DTOC law and normal one are demonstrated. For confirmation of its utility, we processed raw phasor measurement units data via the proposed TD. In the absence of complex power system modelling and historical data, it was verified that the proposed TD is suitable for applications of real-time synchrophasor estimations, especially when the states are corrupted by noise.     

跟踪－微分器在感应电动机定子磁链估计中的应用

针对传统微分器的噪声放大问题及低通滤波器代替纯积分器带来的固有误差问题,对跟踪－微分器在感应电动机定子磁链估计中的应用进行研究。首先,引入跟踪－微分器对检测的定子电流进行了预处理来抑制噪声,再利用跟踪—微分器提取定子电流角频率信息。在此基础上,进一步提出一种利用定子电流角频率信息进行增益及相位补偿的可编程级联低通滤波器代替纯积分器的定子磁链估计方案。仿真与试验结果验证了改进方案的实用性和优越性。     

S7-200PLC在除湿机控制系统中的应用

采用西门子S7-200 PLC为主控制器,配以人机界面TD400C和通信模块EM277,设计了某除湿机控制系统.温度、湿度的采集采用频率输出方式的传感器/变送器,将频率信号接入PLC集成的高速脉冲输入口,定时计数从而得到采样值.控制指令可以从数字输入接口、TD400C或上层计算机获得;系统运行状态也可在数字输出接口、TD400C上显示或传送至上层计算机.