浅埋地雷爆炸作用下固支方板的响应分析

基于有限元软件LS-DYNA,在不同地雷掩埋深度、不同靶板离地间隙以及不同装药量的条件下,对固支方板的响应过程进行数值模拟。对炸药当量、离地间隙、地雷埋深、中心比冲量等影响参数进行分析,结合地雷爆炸载荷的作用特点,用量纲分析法得出地雷载荷作用下靶板中心挠度的无量纲关系式,可以较好的预测试验中地雷爆炸载荷作用下靶板的中心变形挠度,误差均小于15%。分析结果表明:随着地雷掩埋深度和靶板离地间隙的增大,靶板的变形形态越来越接近均布载荷作用靶板的均匀圆顶形变形形貌。

微粗糙面下埋地地雷目标的极化滤波增强

首先采用了二维分数布朗运动来模拟实际地面,利用微扰法给出了微粗糙表面的散射矩阵;其次计算了微粗糙面下某型号地雷目标的极化散射特性,并与平坦地表下的极化特性进行了比较;最后,在考虑地杂波干扰时,研究了杂波环境中埋地地雷目标的极化滤波增强技术,给出了收/发天线的最优极化状态。

我们就是到这儿埋地雷的

扬起的尘土，在大路、在田野、在村里的街道上浮动。在这猪、牛、人、马、车辆汇成的河流里，长着连鬓胡子的武装班长申俊福过来了。他敞着怀，高卷着裤腿，光着两只大脚，肩上扛着个大地雷。汗珠顺着他胡子拉碴的脸往下滚，顺着他袒露的胸膛往下流。一路上喊着：

股民肖像

望“股”生畏 股民小G,入市颇早。熊市斗牛,牛市斗熊,最爱追涨杀跌;割肉断臂伤痕累累,亏损很是不少。于是,痛下决心,将磁卡锁入箱内,自称终生不再谈股。 某晚,有友来访,闲谈间,友请求打开电视,说有一些电视剧颇佳,可看。小G忙说,稍慢,逐从抽屉取出耳塞、墨镜各一副。然后请友开电视。友大惑不解,问之。小G答,如今最怕播股市行情,一看便血压升高手脚冰凉,一夜不得安生矣,故备此。友愕然。

亲子游戏一组(续)

潜水艇 潜水艇,水里跑, 水底下,开大炮。 敌人正在睡大觉, 轰隆一声全报销。

The Use of Ground Penetrating Radar in Municipal Solid Waste Landfill Geotechnical Investigation

The use of GPR （ground penetrating radar） as an auxiliary tool in geotechnical and environmental site investigations has increased in Brazil during the past few years. GPR has been used to delineate contamination plumes, to aid in geological modelling, to detect buried structures and in archaeological surveys. This paper describes and discusses the results ofa GPR site investigation carried out at Gramacho Municipal Solid Waste Landfill in the State of Rio de Janeiro, Brazil. A field study was conducted to detect failure surfaces in its slopes and within the waste mass. The results have shown that： （l） Slip surfaces could be indicated by small continuous voids within the waste mass since there is a good contrast between the dielectric constant of air and municipal waste; （2） Greenhouse gases pools could also be indicated by large voids within the waste mass since there is a good contrast between the dielectric constant of carbon dioxide, methane and municipal waste; （3） Leachate pools present a high electric conductivity that could be easily detected by GPR.