圆锥形接触式激光刀头设计

本文用展开法设计圆锥形接触式激光刀头,导出了刀头几何参数的计算公式。给出了一个设计实例并讨论了各几何参数之间的关系。     

绕有攻角锥体超音速流动的一种数值解法

本文提出了定常超音速无粘有攻角锥体的三维流动问题的数值解法.本方法完全不同于文献[1]中给出的近似级数解法,而是从解椭圆型偏微分方程组着手而得到的精确数值解。本方法的使用仅受到二个极限条件的限制:当局部横向速度分量是超音速时将出现远离锥体的熵奇点;激波过分接近于锥表面时。在附录中给出的计算程序中包合了激波形状初值的估算,从而使计算机时间大大地缩短.与实验结果和其它理论结果的比较证明,本方法是极其令人满意和节省计算机时间的。     

Design of controller using variable transformations for a nonlinear process with dead time

In this work, a globally linearized controller (GLC) for a first-order nonlinear system with dead time is proposed. This is similar to the GLC proposed by Ogunnalke [Ind. Eng. Chem. Process. Des. Dev. 25, 241-248 (1986)] for nonlinear systems without dead time. Two methods are proposed. One is based on the Smith prediction from the model in the transformed domain and the other is based on Newton's extrapolation method. The simulation study is made on the conical tank level process and the results are compared with those obtained using a conventional PI controller and the Smith PI controller based on the transfer function model about the operating point 39%. Finally, experimental results on the laboratory conical tank level process are also given.     

组合锥形液体贮罐的简化设计方法

组合圆锥-圆柱形壳形式的钢贮罐是一种常见的用于储存液体的压力罐。大部分此类压力罐的破坏都由于钢壳的失稳而引起。引起这些破坏的主要原因是没有适当的设计方法来对这类结构进行设计。在本次研究中,提出了简化的设计方法,以保证静水加载的组合钢罐在发生屈曲时的安全。应用非线性有限元模型进行数值模拟,对大变形和几何缺陷对钢罐稳定性的破坏作用进行分析。采用有限元计算结果与非线性回归分析建立函数,将壳的总应力与膜应力关联起来。采用算例说明了所提议设计方法的应用。     

圆波导TM01模激励的加平行板圆锥喇叭的理论分析与实验结果

用解析公式对由圆波导TM01模激励的加平行板圆锥喇叭辐射场进行了分析,并采用有限元软件分析了该天线在不同频率的辐射场、反射系数.理论分析与实验结果表明,由圆波导TM01模激励的加平行板圆锥喇叭辐射轴向为极大值的线极化的远场方向图,在频率为5GHz时增益大于21dB,辐射效率约93～94%.     

Drying of industrial sludge waste in a conical spouted bed dryer. Effect of air temperature and air velocity

To determine the performance of a conical spouted bed dryer for the drying of sludge waste, an experimental study of drying in a spouted bed regime was performed under different experimental conditions. The drying performance was determined based on the time evolution of solid moisture content, and the influence of operating conditions (inlet air temperature, air flow rate, and bed mass) on the drying rate of sludge waste in spouted beds of a conical geometry was analyzed.     

锥面活塞环自动分选机的研究

介绍一种用于锥度检测的锥面活塞环自动分选机。它的控制、数据采集、信号处理都由计算机完成 ,并具有故障诊断、误差补偿、报警、测量结果显示、打印等功能。     

网架螺栓球节点锥头式杆件疲劳性能的试验研究

为了对网架螺栓球节点锥头式杆件疲劳强度进行试验研究,设计了试验方案,对六根锥头式杆件试件和一榀由锥头式杆件构成的桁架试件进行了静力试验和疲劳试验,根据试验结果给出了统计回归公式,并在研究分析的基础上提出了一些看法．     

Stability analysis of generally laminated conical shells with variable thickness under axial compression

Abstract

The buckling of generally laminated conical shells having thickness variations under axial compression is investigated. This problem usually arises in the filament wound conical shells where the thickness changes through the length of the cone. The thickness may be assumed to change linearly through the length of the cone. The fundamental relations for a conical shell with variable thickness applying thin-walled shallow shell theory of Donnell-type and theorem of minimum potential energy have been derived. Nonlinear terms of Donnell equations are linearized by the use of adjacent-equilibrium criterion. Governing equations are solved using power series method. This procedure enables us to investigate all combinations of classical boundary conditions. The results are verified in comparison with Galerkin method and the available results in the literature. Effects of thickness function coefficient, semi-vertex angle, lamination sequence, length to diameter ratio, and initial thickness of the cone on the buckling load are investigated. It is observed that these parameters have considerable effects on the critical buckling load of a conical shell.     

利用麦瓶草病原菌株WP-1开发微生物除草剂初探

从自然感病的麦瓶草近基部分离得到一寄生疫霉菌株(WP-1),土壤接种盆栽试验结果表明,在供试的作物和杂草范围内,该菌的寄主范围相对专一,感病植物主要集中在十字花科、苋科和石竹科;无菌培养滤液强烈抑制麦瓶草幼苗胚根生长,抑制率为86.1%;该生防菌及其代谢产物具有开发微生物除草剂的潜力。对该菌的生物学特性研究表明:菌丝菌落生长的最佳条件为番茄培养基(液),20~28℃,光照,震荡增大通气量有利于菌丝体生长。偏碱性有利于生防菌菌落的生长,但液体培养环境下对培养基的初始酸碱度要求不严格;培养滤液对植物毒性最强的培养条件为Plich’S培养液和马铃薯葡萄糖培养基液PDB,25~30℃,中性偏酸,黑暗,静止培养15d。