振动给料筛分机组的研制与工业应用

介绍了一种代替重型板式给矿机给矿的新型设备－－振动给料筛分机组及工业应用情况。     

我国压力容器用钢的近期进展

本文简要介绍了近年来我国压力容器用钢板和钢锻件的技术进展。一些新钢号研制成功,相关钢板和钢锻件标准的技术水平有了提高,达到了国际先进水平,其中低温用钢锻件标准的技术水平优于国外先进水平的标准。     

Screening for antibiotic residues in the trout by the Four Plate test,Premi test and ELISA test

The effectiveness of various assay systems for the examination of trout was investigated. The Four Plate test (FPT), Premi test and ELISA test were used for determining sulfadiazine/trimethoprim residues in trout. According to the results of the Four Plate test, when trouts were fed with pellets containing antibiotics (sulfadiazine/trimethoprim), the inhibition zones increased according to duration of feed application. In the control group, no inhibition zones were detected. The concentration of the residues accumulated and reached a plateau after 5 days. The antibiotics were detectable in the same concentration as on day 10, but 5 days later (on day 15) they were no longer detectable in the trout by EEC FPT. In contrast to the FPT, 5 days after discontinuing the medicated diet, there were still residues detectable by the Premi test and ELISA test on day 15. According to the ELISA test results of the trout; from day 1 to day 10 the results of sulfadiazine residues were found to be 4.18, 8.02, 9.13, 20.10, 21.32, 20.52, 20.75, 20.99, 20.90, 20.32 ppb, respectively. On day 10, the antibiotics were detectable in the same concentration. On day 15, sulfadiazine residues were found to be 6.82 ppb, but 5 days later (on day 20) they were no longer detectable in the trout. EEC Four Plate method presented less sensitivity and effectiveness in the detection of sulfadiazine.     

A simple method for the inclusion of external and internal supports in the spline finite strip method (SFSM) of buckling analysis

The SFSM is an attractive numerical technique for the buckling analysis of folded-plate structures where general loading regimes and boundary conditions need to be modelled. In implementing splines as interpolation functions in the longitudinal direction of the strip, amended splines have been used conventionally to model the variety of end conditions that may occur. These amended splines are fairly difficult to implement, particularly so if internal restraints are also to be specified. A simple technique for replacing the specification of dedicated amended splines is presented in this paper. The method is then employed to study the local buckling of flat plates under longitudinally and transversely varying compression and bending with different boundary conditions at the ends.     

On the identification of microstretch elastic moduli of materials by using vibration data of plates

In the present work, the vibration problems of rectangular plates modeled by Eringen’s microstretch theory are investigated for the identification of the upper bounds of the microstretch moduli of the plate material. The calculated frequencies of the plates are obtained by extending the Ritz method to the microstretch plates. The three dimensional (3D) vibration analysis of the plates shows that some additional frequencies occur among the classical frequencies as characterizing the microstretch effects. Then it is also observed that these additional frequencies disappear and only the classical frequencies remain with the increasing values of microstretch constants. The inverse problem is established for the identification of the upper bounds of the microstretch elastic constants as an optimization problem where an error function is minimized.     

一种基于字符分割与字符识别的LPR方法

对车牌识别(LPR)系统中字符分割与字符识别方法进行探讨.根据车牌字符的特点,首先利用投影法采用水平扫描和垂直扫描进行字符分割,接着对字符图像进行归一化处理,实现对字符的完全分割.在此基础上,利用BP神经网络识别算法实现车牌字符的识别,从而提高系统的识别速度和识别率.数字仿真的识别结果验证了该方法的正确性和有效性.     

一种车牌自动识别系统设计方法

通过对连续视频流分析的方法判断并捕获车牌图像帧;基于数学形态学方法和边缘特征分析来进行车牌定位,进行二值化、引入多指标联合评价函数判断反色等处理;最后基于连通体分析的方法切分字符。实验表明本系统设计方法是可行的。     

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%.     

Sheeting interaction failure, from yield-line to two-strip model

This paper presents 20 years of research on failure of sheeting subjected to combined concentrated load and bending moment, performed at Technische Universiteit Eindhoven. The aim of this research is to develop accurate, insight providing design rules using simple mechanical models, based on observed failure modes. The paper summarizes the performed experiments, finite-element simulations, and analytical models. It is concluded that mechanical models may be feasible only for sheeting without stiffeners in web and flanges. For sheeting with stiffeners, the models become so complex that it is not likely that they will lead to simple design rules.     

厚板V形弯曲成形中切口大小对成形质量的影响

在V形件弯曲成形中,工艺切口开槽的形状、大小确定,成形特点描述,工艺制定都有一定难度.本文通过有限元模拟的方法对V形弯曲成形中切口工艺进行研究,并使用正交试验来分析切口相关尺寸对成形结果的影响,即切口直边长直接影响到内外应力应变大小,且影响比较大;圆角半径对内部等效应变影响较小,对外部应力应变以及内等效应力影响较大;直边宽只对外部等效应力应变影响较大(相关名词见正文).这些结论,为工艺切口的设计提供指导参考.