混合结构楼房爆破拆除倒塌范围的确定

通过对混合结构楼房爆破倾倒过程特点的分析,提出了楼房在倾倒过程中的运动计算模型,并应用体积平衡原理,得到这类楼房爆破爆堆参数计算公式,用该公式计算的结果与实例中爆堆实测数据相比较,相对误差不超过11%.     

催化裂化余热锅炉省煤器的改进

针对重油催化裂化余热锅炉省煤器经常"爆管"而难以运行的问题,分析原因后提出三种改进方 案,并优选一种方案实施,成功地解决了该问题,同时大幅度提高了锅炉过热蒸汽产量,节能效果显著。     

Evaluation of air blast parameters in block cave mining using particle flow code

Air blast, a sudden mass movement of air, can occur in underground mining system where caving develops an extensive mass of unsupported rock spanning a large void. Air blast can result in injury to mine personnel, damage to equipment or disrupts mine operation. Evaluation of air blast parameters is, therefore, an essential part to develop strategies to mitigate the hazard. The properties of a muckpile or a caved zone are significant factors affecting the magnitude of air blast in particular on the undercut and extraction levels. This research investigates the effect of muckpile properties on air flow using the numerical code, PFC2D. The critical parameters such as thickness, block size and porosity (swell factor) of the muckpile have been studied to quantify how much they could change the magnitude of air pressures and velocities while the air flows through the muckpile. It was found that the porosity of the muckpile is the most effective parameter on the magnitude of air blast and by designing a thick layer of blasted rock with low porosity in the caved zone, the intensity of the air blast can be significantly reduced. The findings of this study can be used to design air blast plugs or bulkheads in order to isolate any potential air blast from the active workings, or to quantify the minimum thickness of the muckpile above extraction levels to manage air blast hazards.     

10层框架结构楼房爆破拆除的数值模拟

以沈阳东电医院住院部(南楼)爆破拆除工程为例,根据东电医院住院部复杂环境及其具体情况采用LS-DYNA有限元软件对建筑物爆破拆除三种设计方案进行模拟分析,并将方案比选,得出了采用半梯形切口、半秒延时雷管的最佳设计方案。按此方案进行了爆破拆除施工并将实际倒塌结果与模拟结果进行对比。结果表明,二者在爆堆的尺寸形状上的误差均在10%以内,形成时间的误差为4.4%,在工程允许范围内。     

人工神经BP网络预测露天采场爆堆矿石质量的方法

露天矿采场的矿石质量数据预测控制的准确程度直接影响着矿石质量的利用，它是矿石质量管理的原始数据，是输出矿石质量能否稳定和均匀的前提和保证。人工神经BP网络控制预测露天矿采场爆堆的矿石质量，既可减轻目前人工爆堆取样的劳动强度，又可减少大量的化验费用。     

基于非线性理论的抛掷爆破爆堆形态预测

抛掷爆破可以大幅度降低矿山生产成本.从抛掷爆破效果出发研究设计参数对爆破效果的影响,利用矿山搜集的爆破样本,运用非线性理论分析得到抛掷爆破效果的主要影响因子.以影响因子和样本作为预测的基础,运用聚类分析、回归分析、线型插值等方法预测爆堆形态、有效抛掷率和爆堆松散系数.经现场实际检验,预测结果准确率达90%以上,达到了现场应用的要求.     

Toward the biomimetic implant surface: Biopolymers on titanium-based implants for bone regeneration

Replacing malfunctioning tissues with titanium-based implants has become a widespread practice spurred by population aging. Advances in biomaterials, technology and implantation protocols have led to increasing expectations on the applicability and durability of implants. The field has recently moved from a bioinert to a bioactive paradigm due to surface modifications that trigger specific responses on the surrounding tissues. Biopolymeric surface coatings have taken up a central role in these developments. The use of these and other biomimetic strategies on implants provides greater control over material–cell interactions and it is aimed at improving long-term clinical results by replicating some of the structures and mechanisms of living tissues. This review summarizes the state of the art of biomimetic implants and discusses the main directions and challenges of this field toward a more predictable and successful implant osseointegration.     

3D, chemical and electrochemical characterization of blasted TI6Al4V surfaces: Its influence on the corrosion behaviour

The blasting process to increase the roughness of the surface of metallic biomaterials is widely used. As a consequence, one can produce a renewed surface with different topography and chemical composition compared to the original one, which can alter the general corrosion behaviour of the samples. With this idea, the aim of this work is not only the topographical and compositional characterization of blasted surfaces of Ti6Al4V alloy but mainly its influence on the corrosion behaviour of these modified surfaces. The surfaces of Ti6Al4V alloys were blasted with SiO₂/ZrO₂ and Al₂O₃ particles of different size in order to obtain different roughnesses. To carry out the microstructural and topographical characterization of the blasted surfaces, the scanning electron microscopy (SEM) coupled with an energy dispersive X-ray (EDX), the contact profilometry method and the 3D characterization by means of stereo-Fe-SEM have been used. By means of stereo-Fe-SEM, the roughness and the real surface area of the rough surfaces have been calculated. The microstructural, topographical and compositional results have been correlated with the corrosion behaviour of the samples immersed in Hank's solution and studied by means of electrochemical impedance spectroscopy (EIS). The blasting process alters topographical and chemically the surface of the samples. These modifications induce to an increase in the capacitance values of the roughened samples due to the prevalence of the effect of electrochemically active areas of Ti6Al4V surface over the effect of the presence of Al₂O₃ and ZrO₂ particles on the blasted surfaces. However, the general corrosion behaviour of the samples is not drastically changed.     

基于SVM的露天矿爆堆矿石质量预测研究

露天矿采场的矿石质量数据的准确程度是输出矿石能否均匀和稳定的前提和保证。根据台阶爆破的抛掷理论,利用支持向量机(SVM)预测露天矿采场爆堆的矿石质量,既可及时、准确地预测出爆堆矿石质量情况,又可减轻人工爆堆取样的劳动强度。     

无底柱超高分段室内物理放矿模拟试验

结合武钢金山店铁矿生产中遇到的问题,通过进行室内物理放矿模拟试验对35m超高分段条件下放矿回收指标和放出体形态进行较为详尽的研究,揭示出损失率、贫化率等回收指标的变化情况,放出体形态与崩矿步距之间的关系,进而为指导生产提供理论依据。