火电机组蒸汽在线钠表测量准确性研究

通过比较二阶微分火焰光谱法、离子色谱法和在线钠表法测量蒸汽中钠离子的准确性,检验了Orion、Swan、Polymetron等公司生产的蒸汽在线钠表的测量结果。表明:在保证仪表的最佳工况下,目前火电机组蒸汽在线钠表能够满足蒸汽中痕量钠离子准确测量的要求。在线钠表的测量准确性受电极性能、流体流速、碱化剂浓度、外界干扰等因素的影响,应定期对仪表进行清洁维护保养。     

Calibration of split Hopkinson pressure bar system with special shape striker

In order to present basic guidance for system calibration of split Hopkinson pressure bar(SHPB) with the special shape striker,wave characteristics and dynamic responses of SHPB under striker impact were analyzed.Stress generated by the special shape striker tends to have a half-sine waveform and has little wave dispersion during its propagation.Impact velocities of the special shape striker and peak values of generated stress still have linear relation but with a different coefficient from that of cylindri...     

卢龙采石场台阶爆破飞石事故的FTA方法评价

爆破飞石常常对人员和设备造成致命伤害,然而对事故的分析和评价往往凭经验进行.采用事故树方法对采石场爆破飞石进行了分析,通过最小割集原理分析,发现加强施工监督是减少卢龙采石场爆破飞石事故的最有效措施.     

金阳公路下赋矿体开采方法的有限元法优选

为了对金阳公路下赋矿体开采的三种采矿方法进行优选,利用三维有限元方法。采用体积能量释放率作为指标,最终确定中深孔落矿嗣后胶结充填采矿法为最优采矿方案。     

双矿柱体系变形破坏及承载特性的试验研究

 为揭示外部载荷作用下矿柱体系的力学响应特性,开展单矿柱及双矿柱试样组的压缩试验,监测并分析矿柱变形破坏过程中的荷载、变形及声发射信息。研究表明：单矿柱压缩过程中,随着裂纹演化,其承载能力逐渐弱化,当其不足以承担外部荷载时,试验机储存的弹性能将迅速释放并导致矿柱突然破坏;相同力学性能矿柱组压缩过程中,两矿柱基本能均匀承载,协调变形且几乎同时丧失承载能力;不同力学性能矿柱组压缩过程中,低强度矿柱先出现裂纹,承载能力缓慢下降,与此同时荷载向高强度矿柱转移,当高强度矿柱出现宏观滑移时,双矿柱试样组整体随之丧失承载能力;单个矿柱的承载能力、应力状态及外部荷载与能量环境均对双矿柱体系的整体稳定有着显著的影响;进行地下矿床开采时,在设计常规矿柱基础上预留高承载能力边界矿柱,将能有效预防矿柱群大规模突发性失稳灾害。     

基于LabWindows/CVI的双通道数据采集系统

介绍了使用LabWindows/CVI和DAQ/PXI-2005数据采集卡搭建的数据测量系统。通过传感器将所测特征信号变为电信号传输,再用数据采集卡采集传送给处理器,用LabWindows/CVI搭建数据处理和显示的人机交互界面,实现对物体特征的测量。该系统可以实时显示所测物体特征,修改数据采集时的各项参数,显示采集到数据的波形,存储、调用采集到的数据。     

岩石类SHPB 实验理想加载波形的三维数值分析

从SHPB 实验装置加载波形入手, 运用非线性动力分析有限元程序对传统矩形波和改进的半正弦波加载下不同直径入射杆中的波形弥散情形进行分析, 显示并验证了SHPB 半正弦加载波随杆径增大无明显弥散。该波形是用于岩石类脆性材料大直径SHPB 测试的理想波形。     

非爆破岩理论和技术发展与展望

地下资源开采及地下空间开发利用规模不断加大,促使非爆破岩技术得到了长足发展,并衍生出机械刀具破岩、水力破岩、微波破岩、热冲击破岩、膨胀破岩、联合破岩等技术。本文阐述了各类非爆破岩理论,并综述了各类非爆破岩技术的发展与应用进程。针对目前非爆破岩技术的发展瓶颈和面临的挑战,展望了非爆破岩理论与技术的发展方向。为满足深地战略重大需求,非爆破岩亟需完成理论突破、技术变革、设备升级,以实现复杂地质环境下坚硬岩石的安全、高效、经济、智能及绿色破碎。     

Energy consumption in rock fragmentation at intermediate strain rate

In order to determine the relationship among energy consumption of rock and its fragmentation, dynamic strength and strain rate, granite, sandstone and limestone specimens were chosen and tested on large-diameter split Hopkinson pressure bar (SHPB) equipment with half-sine waveform loading at the strain rates ranging from 40 to 150 s⁻¹. With recorded signals, the energy consumption, strain rate and dynamic strength were analyzed. And the fragmentation behaviors of specimens were investigated. The experimental results show that the energy consumption density of rock increases linearly with the total incident energy. The energy consumption density is of an exponent relationship with the average size of rock fragments. The higher the energy consumption density, the more serious the fragmentation, and the better the gradation of fragments. The energy consumption density takes a good logarithm relationship with the dynamic strength of rock. The dynamic strength of rock increases with the increase of strain rate, indicating higher strain rate sensitivity. Foundation item: Projects(50674107, 10472134, 50490274) supported by the National Natural Science Foundation of China