远程爆破振动测试系统设计

为了指导爆破施工方法,制定防震措施,减少振动危害,介绍了一种由爆破振动采集器、远程服务器及客户端组成的远程爆破振动测试系统。爆破振动采集器能完成爆破振动信号的采集、分析、预测和上传,远程服务器实现了网络接收原始数据及分析报告,客户端实现了远程数据查询。该系统具有自动触发、负延迟记录、爆破分析预测及数据查询网络化的优点。     

定向断裂控制爆破研究成果分析

从切槽爆破研究成果分析,得出切槽爆破在一定程度上可以控制岩体围岩成形,其孔间距可加大1.5~2.0倍;从定向断裂控制爆破(聚能药包)研究成果分析,得出定向断裂控制爆破(聚能药包)具有较好的聚能效应,定向断裂爆破效果较好,同时施工工艺简单。     

做芝麻糖

今天 中午,我和妈妈一起做芝 麻糖。我们先把芝麻洗干净,然后放入锅中炒。炒 芝麻的活由我来担任。我拿 着一个大 勺子 不停 地翻 来翻 去,芝麻 受热 后,像一 个个顽皮的小孩,从火 热的锅里跳出来。妈妈 尝了尝说:“芝麻炒熟 了,出 锅。” 妈 妈 把 芝 麻 倒 入 一 个 大 碗 里 ,然 后 在锅里放 入几 大勺 糖,用勺 子把 锅 里 的糖翻过 来翻过 去,直到 把糖 炒化 。 然 后,妈 妈一 下子 把所 有的芝 麻都 倒 进 锅里,把芝麻和 糖搅 拌在 一起 ,然 后 出 锅放在菜 板上 ,压 平。过 一会 儿,趁 …     

捧上来一条鲨鱼

 大海边,有一个男孩和三个女孩在堆沙子城堡。芝麻巨人踏着海水,一步一步朝他们走去。“我来了,我是芝麻巨人。”芝麻巨人跟小孩们打招呼。小孩们都吃惊地看着她。     

边坡光面(预裂)爆破质量数字化分析

数字化分析是爆破行业在信息时代行业发展的必然趋势,涉及爆破工程作业的各个层面。先进的施工工艺、施工机械和测量仪器的广泛使用给路堑边坡爆破质量评价数字化的可行提供支持和保障,如何利用这些资源,开发符合自身特点的数字化评价系统是本文讨论的问题。     

基于神经网络的炸药与岩石匹配的研究

文章基于MATLAB神经网络工具箱平台,利用BP神经网络建立炸药岩石匹配模型,并根据工程实践中收集的数据和文献中的经典数据作为网络模型的学习训练和检验样本,从岩石爆破特性和爆破效果等因素出发来预测炸药爆炸特性和爆破设计参数,并结合某工程实例数据为输入值对模型进行检验,得到输出值预测误差均在10%以下,仿真效果较好。证明本模型对工程爆破实践有一定的指导意义和参考价值,并为炸药岩石匹配问题的研究提供了较好的思路。     

高级数字信号处理器及其在图象领域中的应用

数字图象处理技术的特点之一是所需运算量大,现在已经有许多先进的DSP完全可以胜任这样大的运算量,从而实时实现系统。另外,使用DSP还有成本低,容易开发的好处,这里我们将提出一个基于H.263标准的可视电话系统,用美国德洲仪器公司最新的多媒体DSP-TMS320C80来实现。     

刘桥二矿六煤层断裂复杂程度的分形评价

煤矿中的断裂网络是一种具有统计自相似性的分形体系，其结构的复杂程度可用分维来定量描述，对皖北局刘桥二矿6煤顶板的构造复杂程度进行了评价，并对未采区进行了初步预测。     

一种基于LPCC的天然地震和人工爆破识别算法

线性预测倒谱系数（LPCC ）可以反映时间信号频率响应和谱包络。本文提出了一种基于LPCC来提取地震信号特征,并且采用高斯混合模型（GMM ）来判断震源类型是天然地震还是人工爆破的算法。实验结果表明LPCC在天然地震和人工爆破识别中的具有明显的可行性和有效性。最后,以同一次事件3个台站记录波形数据来识别天然地震和人工爆破类型,分析了LPCC在识别时的稳定性,并且有较高的识别率。     

南国之极致,龙口之含珠——蘋洲书院品牌定位与文化设计

湖南永州蘋洲书院创始于清初,数十年来早成荒芜,论文在对蘋洲书院历史沿革、地理特征、文化内涵进行客观研究的基础上,对其建筑格局、蘋洲八景等品牌定位与文化设计提出了一整套系统而新颖的人文规划。     

Mesh size effect in numerical simulation of blast wave propagation and interaction with structures

Numerical method is popular in analysing the blast wave propagation and interaction with structures.However,because of the extremely short duration of blast wave and energy trans-mission between different grids,the numerical results are sensitive to the finite element mesh size.Previous numerical simulations show that a mesh size acceptable to one blast scenario might not be proper for another case,even though the difference between the two scenarios is very small,indicating a simple numerical mesh size convergence test might not be enough to guarantee accu-rate numerical results.Therefore,both coarse mesh and fine mesh were used in different blast scenarios to investigate the mesh size effect on numerical results of blast wave propagation and interaction with structures.Based on the numerical results and their comparison with field test re-sults and the design charts in TM5-1300,a numerical modification method was proposed to correct the influence of the mesh size on the simulated results.It can be easily used to improve the accu-racy of the numerical results of blast wave propagation and blast loads on structures.     

Rate-sensitive numerical analysis of dynamic responses of arched blast doors subjected to blast loading

Current practice in analysis and design of blast doors subjected to blast loading considers only simple boundary conditions and material properties. The boundary conditions and material properties, in fact, have considerable influence on the response of blast doors subjected to blast loading. In this paper, the dynamic responses of a reinforced concrete arched blast door under blast loading were analyzed by the finite element program ABAQUS, combined with a previously developed elasto-viscoplastic rate-sensitive material model. And the effect of the surrounding rock mass and contact effect of the doorframe were also taken into account in the simulation. It is demonstrated that the strain-rate effect has considerable influence on the response of reinforced concrete blast door subjected to blast loading and must be taken into account in the analysis.     

卷烟厂风力输送系统参数的选择与计算

通过对风送装置与机械输送设备的分析比较,根据为卷烟厂设计风送设备的实际经验,介绍了卷烟厂烟叶、烟梗和烟丝等不同状态的物料之风力输送系统中各项参数的选择与计算的方法步骤,可供设计时参考.     

Analysis of blast wave propagation inside tunnel

The explosion inside tunnel would generate blast wave which transmits through the longitudinal tunnel. Because of the close-in effects of the tunnel and the reflection by the confining tunnel structure, blast wave propagation inside tunnel is distinguished from that in air. When the explosion happens inside tunnel, the overpressure peak is higher than that of explosion happening in air. The continuance time of the blast wave also becomes longer. With the help of the numerical simulation finite element software LS-DYNA, a three-dimensional nonlinear dynamic simulation analysis for an explosion experiment inside tunnel was carried out. LS-DYNA is a fully integrated analysis program specifically designed for nonlinear dynamics and large strain problems. Compared with the experimental results, the simulation results have made the material parameters of numerical simulation model available. By using the model and the same material parameters, many results were adopted by calculating the model under different TNT explosion dynamites. Then the method of dimensional analysis was used for the simulation results. As overpressures of the explosion blast wave are the governing factor in the tunnel responses, a formula for the explosion blast wave over-pressure at a certain distance from the detonation center point inside the tunnel was derived by using the dimensional analysis theory. By comparing the results computed by the formula with experimental results which were obtained before, the formula was proved to be very applicable at some instance. The research may be helpful to estimate rapidly the effect of internal explosion of tunnel on the structure.     

春雷霉素WP防治水稻稻瘟病田间药效试验

进行了春雷霉素防治水稻稻瘟病试验,试验结果表明,2％春雷霉素WP对水稻稻穗瘟有较好的防效,防效达91．0％-94．2％,试验剂量下对水稻安全无害,可以大面积推广应用,生产上推荐用量为112．45—181．25g／hm^2。     

基于GA-BP网络的铁水硅质量分数预测系统

提出将BP神经网络与遗传算法(GA)相结合,建立了三层GA-BP神经网络模型,模型利用遗传算法来修改网络的连接权值,构筑进化型的神经网络模型,缩短网络学习训练时间,提高模型预测精度。炉温预测主要是高炉铁水硅质量分数的预测,当要求硅质量分数预报的绝对误差为±0.05%时,命中率为90%。结果表明,GA-BP网络模型比传统的BP网络模型能够获得更高的精度。     

爆炸冲击波在城市地下通道内传播规律的数值模拟

城市地下过街通道是城市重要的交通系统组成部分,也经常会成为恐怖分子爆炸袭击的对象。为了更好的了解爆炸冲击波在地下过街通道中的传播规律,本文通过数值模拟分析了13KG炸药在通道爆炸后冲击波的传播。分析过程中分别考虑了炸药起爆位置及通道顶盖对冲击波传播的影响。分析结果表明当TNT在通道内起爆后,通道顶部的角落将受到更大的冲击波压力作用,当冲击波从出口向外传播时将发生明显的射流现象;当通道出口有顶盖时,炸药在出口的起爆将明显加强通道内部及出口梯道的压力峰值。     

Simulation of Airblast Load and Its Effect on RC Structures

In the analysis of a structure subjected to an explosion event, the determination of the blast load constitutes a crucial step. The effect of the blast load on the structure depends not only on the peak shock overpressure, but also the impulse (hence the duration). For structures with a regular geometry, the blast load may be fairly well estimated using appropriate empirical formulae; however, for more complex situations, a direct simulation using appropriate computational techniques is necessary. This paper presents a numerical simulation study on the prediction of the blast load in free air using a hydrocode, with focus on the sensitivity of the simulated blast load to the mesh grid size. The simulation results are compared with empirical predictions. It is found that the simulated blast load is sensitive to the mesh size, especially in the close-in range, and with a practically affordable mesh grid density, the blast load tends to be systematically underestimated. The study is extended to internal blast cases. An example concrete slab under internal explosion is analyzed using a coupled analysis scheme. The internal blast load from the simulation is examined and the response of the RC slab is commented.     

BP神经网络PID控制在高炉TRT顶压控制系统中的仿真

为改善传统PID的控制缺陷,提出了BP神经网络PID控制算法应用于高炉TRT顶压控制系统中的设计构想,并针对影响高炉炉顶压力稳定的两个重要参数,运用Matlab软件进行仿真,结果表明,该优化控制算法对高炉顶压控制系统的控制效果明显优于传统PID。     

高炉TRT控制系统模型仿真研究

根据高炉TRT工艺和影响高炉顶压稳定的因素,以及对高炉TRT系统的管路分析,建立高炉顶压TRT系统数学模型。应用Matlab对静叶单独调节高炉顶压时系统的数学模型进行仿真验证,为进一步改善高炉顶压的稳定提供理论依据。