178 research outputs found

    柿竹园矿地下特大爆破的微震监测技术研究

    Get PDF
    柿竹园多金属矿采用中深孔大规模崩落工艺回采矿柱,特大爆破回采过程中,对岩石微震事件进行了监测,介绍了微震监测系统。通过微震监测,了解到群矿柱与垂悬顶板余震的时空变化特点,对群矿柱中的应力集中区域进行了较好的定位,进而对群矿柱与垂悬顶板进行了基于微震监测结果的稳定性评价,为井下安全生产和下一步回采矿柱的顺序提供了依据

    Study on the Characteristics of Loss Ratio and Loading-unloading Response Ratio before Rock Failure

    Get PDF
    以多种岩石循环加卸载声发射试验为基础,针对岩石损耗比和加卸载响应比特性进行了研究,探索岩石在受载过程中的内部损伤演化和破坏前兆特性。结果表明,在; 循环加卸载下角岩等三种岩石损耗比变化特性一致:低应力水平阶段损耗比较大,呈明显下降趋势;中等应力水平阶段比值下降趋势较平缓;高等应力水平阶段比值; 趋于稳定,在0.08 ~; 0.10时,试样破坏。而钨钼矿等三种岩石加卸载响应比变化特性一致:低应力水平阶段卸载时几乎没有声发射,加卸载响应比较大;中等应力水平阶段卸载时声; 发射较活跃,比值下降至1左右;高等应力水平阶段卸载时声发射很活跃,当比值重新大于1时,试样破坏。试验结果都体现了岩石内部损伤从很小到稳定扩展再到; 不稳定扩展的过程。可见,损耗比和加卸载响应比的变化特性均可用于评价岩石损伤情况,也可用作岩石破坏预测的参考依据。On the basis of the acoustic emission for rock under cyclic loading and; unloading,the characteristics for the loss ratio and loading-unloading; response ratio of rocks is studied,and the evolution of the internal; damage in the course of loading and the precursor characteristics of; failure are explored. The results show that the variation; characteristics of loss ratio of three kinds of rocks like hrnfelswere; are consistent under loading and unloading conditions; The loss ratio is; relatively large in the low stress level stage,and it shows a clear; downward trend. After entering the medium stress level,the ratio; decreases with a relatively flat trend. In higher stress level,the ratio; tends to be stable,and the specimen fails at 0.08~ 0.10. At the same; time,the variation characteristics of loading-unloading response ratio; of three kinds of rocks like tungsten and molybdenum ores are; consistent. There were almost no acoustic emission at the unloading; stage in the low stress level stage,and the loading-unloading response; ratio were relatively large. Acoustic emission was more active at the; unloading stage in the medium stress level,and the ratio dropped to; about 1. In higher stress level,acoustic emission was very active at; unloading stage,and the specimen failed when the ratio increased over 1; again. The results reflect the process of rock internal damage from; small to steady expansion and then to unstable expansion. So the; variation characteristics of loss ratio and loading-unloading response; ration can be used to evaluate the damage of rock,and also can be used; as a reference for prediction of rock failure.国家十二五科技支撑计划项

    Study on subsurface damage depth and morphology of optical elements

    Get PDF
    根据化学蚀刻法,提出了一种光学元件亚表面损伤的检测方法,分别观测了磨削和抛光后k9玻璃蚀刻后的亚表面损伤。研究表明:光学元件磨削亚表面损伤在光学显微镜下的表现形式为弹坑状缺陷和脆性裂纹;光学元件抛光后也产生了亚表面缺陷,其在AfM下的表现形式为细长条纹状划痕。In this paper,a detection way of subsurface damage in optical elements was put forward based on the chemical etching method.After grinding and polishing,we observed the subsurface damage of K9 glass under different etching time.The study indicates that the manifestations of the grinding subsurface damage under optical microscope are crater-like defects and brittle cracks;the optical elements also has subsurface damage after polishing,and the polishing subsurface damage under AFM manifests as slender striped scratches.国家自然基金项目(51275433); 福建省自然科学基金项目(2010J05122

    Research on Detection of Subsurface Damage on Grinding Optical Elements

    Get PDF
    基于氢氟酸刻蚀对光学元件亚表面裂纹影响的刻蚀模型,将化学刻蚀、逐层抛光技术和激光共聚焦扫描技术相结合,提出了一种磨削加工光学元件亚表面损伤的检测方法。实验证实该方法得到的亚表面损伤深度与公认的亚表面损伤预测模型的预测结果吻合性较好,是一种可靠的亚表面深度检测方法。Based on the etching model which hydrofluoric acid etching has an impact on the subsurface cracks of the optical elements, combined chemical etching, step-by-step polishing techniques and confocal laser scanner,a method of detecting sub-surface damage of the optical element was proposed.Research shows that this detection method is intuitive and effective,and the depth of subsurface damage match with the grinding results predicted by the model.国家自然科学基金(51275433); 福建省自然科学基金(2012J05098

    中药质量控制与安全性评价中的分析化学

    Get PDF
    本文论述了中药现代化实施中进行质量控制的“5P”(GAP、GCP、GLP、GMP、GSP)系统工程 ;结合本实验室近年来以“5P”指导中药质量控制与安全性评价所做的一些工作 ,阐明了将分析化学应用于中药质量控制与安全性评价的策略与方法 ,提出了分析化学在中药现代化系统工程及重大科学问题的解决中所能发挥的重要作用

    Surface Biochemical Modification for the Titanium Implants

    Get PDF
    综述近年来钛植入体表面生物化学设计和改性的研究进展,重点介绍植入体表面自组装改性新技术及其在生物医用材料中的应用。This paper reviews the progress in biochemical design and modification for the surfaces of titanium implants in recent years,the emphasis being laid on the introduction of the surface molecular construction, self-assembly technique and its application in biomedical materials

    厦门地区非饱和残积土抗剪强度的试验研究

    Get PDF
    非饱和残积土是厦门地区诸多填方工程的工程用土,而岩土工程的强度与稳定性问题都涉及到非饱和土的抗剪强度及其指标.采用滤纸法测定非饱和残积土的基质吸力,通过一系列的直接剪切试验,测定不同初始含水量状态下土的抗剪强度及其强度指标.试验结果表明:基质吸力随着含水量、体积含水量或饱和度的增加而减小.当含水量小于16%,体积含水量大于35%或者饱和度大于70%时,基质吸力对含水量的变化非常敏感.在低基质吸力区,抗剪强度随着基质吸力的增加显著增加,表观粘聚力随基质吸力的增大而线性增加;在高基质吸力区,强度随基质吸力的增加变化不大,表观粘聚力的增长速率减小.表观内摩擦角仅在基质吸力较小时增加而后可近似为某一定值

    红外多光谱遥感数据的校准

    Get PDF
    主要介绍了一种对由特定红外图谱一体化系统采集的光谱数据进行校准与分析的方法。在实验部分,首先对得到的设定已知特定温度的黑体红外光谱数据进行归类和整理,然后在最大保留特征信号的条件下利用不同的滤波算法与滤波窗宽尽量消除信号噪声,并采用偏最小二乘算法对所得信号进行校准,使之与理论值相符。最后利用校准结果构建数学模型,并考虑主成分个数这一概念,检验模型准确度。通过数据分析可知,由这个特定红外图谱一体化系统采集的光谱数据经偏最小二乘算法校正后与理论值相近,此时能够拟合出校正数列与波数之间的函数关系,且受温度影响较小

    柿竹园多通道微震监测系统的建立及其应用

    Get PDF
    在柿竹园多金属矿床,由于大量集中采空区群的存在,采矿生产过程中地压现象显现严重,安全生产受到严重威胁。为此,公司与长沙矿山研究院合作,在优化采矿工艺的基础上,先后建立了多种常规地压监测系统,并从加拿大ESG公司引进地压监测设备,于2008年11月建立了国内矿山最大通道的全数字型微震监测系统。详细介绍了微震监测系统的建立、优化及其现场应用情况,论述了多通道微震监测技术在矿山地压灾害防治方面所展示的优势和效果

    猪胰铁蛋白释放铁和磷酸盐的动力学特性

    Get PDF
    猪胰铁蛋白(p ig pancreas ferritin,PPF)铁核由179 phosphate/PPF和1698 Fe3+/PPF组成,平均磷铁比值为1∶9.5.PFF铁核表层由较高的磷铁比组成.选用电子光谱技术研究PPF释放铁和磷酸盐全过程,发现PPF以两种不同速率途径释放铁与磷酸盐.在弱酸条件下,PPF释放铁的速率明显高于在弱碱条件下的速率,证实PPF蛋白壳的柔性调节能力强弱是控制释放铁和磷酸盐速率的重要因素之一
    corecore