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精细爆破要求精确控制炸药爆炸能量释放与介质破碎和抛掷的过程。为了实现精细爆破的要求,需要有准确的地形资料、先进的设计方法以及精确的理论计算和数值模拟。采用ShapeMetrix3D三维摄影测量系统为获得准确的爆区三维地形资料并建立最初的三维模型提供了有效的工具。基于Windows开发环境,利用ShapeMetrix3D三维摄影测量系统获得三维地形资料并建立地形数据库,以C#作为开发工具,开发了能够实现深孔布置、深孔三维坐标获取、装药量计算等功能的露天深孔爆破设计系统,为精细爆破提供了先进的设计平台。系统可以准确地再现爆区的地形地质条件,实现人机交互爆破设计,准确地确定孔位、孔网参数和爆破药量,使爆破效果和爆破有害效应得到有效的控制,最终实现安全可靠、绿色环保及经济合理的爆破作业。 相似文献
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传统露天矿山爆破设计与施工多基于爆破作业人员的经验或工程类比法实施,普遍存在设计偏差大、钻孔精度低、爆破大块多等问题。为提高台阶爆破工程中设计与施工的匹配度,减少人工、材料和机械的浪费,有效改进爆破效果,开发了一套智能化台阶爆破设计优化系统软件,该软件具有台阶爆破设计、爆堆块度分布统计分析、爆破振动分析与预测、爆破效果综合评价等模块功能,软件使用过程中基于高精度GPS测量技术,提取爆破对象原始数据完成自适应设计,并将设计成果导出到施工现场。以贵州某水泥厂露天石灰石矿山开采为例,运用GPS采集当前采矿区域地形数据,结合现场实际进行台阶爆破智能化设计,再通过GPS技术将设计数据精确反馈到施工现场,指导现场施工。结果表明,智能化设计软件自适应能力强,采用基于GPS的智能化设计,提高了设计和钻孔的准确度,降低大块率33%,改善爆破效果显著,实现了设计与施工的精细管理,达到安全、经济、高效采矿的目的。 相似文献
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爆破荷载作用下岩石边坡动态响应的FLAC3D模拟研究 总被引:11,自引:1,他引:11
已有的岩石边坡爆破动力响应分析多用有限单元法.作者尝试运用FLAC3D的动力分析模块进行岩石边坡爆破动力响应分析.建立了能够反映主要地质构造的三维岩石边坡数值模型.介绍了三维有限差分程序FLAC3D动力分析的理论基础,包括边界条件的设定、动力荷载的输入、阻尼的选取以及岩体本构模型的选择.采用FLAC3D模拟了该岩石边坡在爆破荷载作用下的动态响应.分析了爆破结束后边坡体内位移场、应力场、速度场以及塑性区的分布情况,并与爆破前进行对比.将计算结果与实测数据进行了比较,结果表明FLAC3D用于爆破荷载作用下岩石边坡动态响应的数值模拟是可行的. 相似文献
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《工程(英文)》2017,3(4):504-511
The stability of pump-turbines is of great importance to the operation of pumped storage power (PSP) stations. Both hydraulic instabilities and operational instabilities have been reported in PSP stations in China. In order to provide a reference to the engineers and scientists working on pump-turbines, this paper summarizes the hydraulic instabilities and performance characteristics that promote the operational instabilities encountered in pump-turbine operations in China. Definitions, analytical methods, numerical and experimental studies, and main results are clarified. Precautions and countermeasures are also provided based on a literature review. The gaps between present studies and the need for engineering practice are pointed out. 相似文献
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Chinedu Nweke Erika Martin Todd Gehr Donald Brophy Daniel Carl 《Hemodialysis international. International Symposium on Home Hemodialysis》2015,19(2):323-329
Arteriovenous graft (AVG) thrombosis is a frequent cause of graft failure. We evaluated coagulation protein concentrations, platelet function, and viscoelasticity factors in 20 hemodialysis (HD) patients with AVGs. The goal was to determine whether significant differences in protein concentrations, platelet function, and viscoelasticity factors exist among dialysis patients requiring frequent AVG declot procedures vs. those who do not. Twenty HD patients were enrolled: 10 frequent clotters (>3 declots in the previous year) and 10 were nonclotters. Patients on antiplatelets or chronic anticoagulation were excluded. Laboratories were drawn pretreatment and heparinase was added to counteract any potential heparin effect. Coagulation protein concentrations including tissue factor (TF), thrombin/antithrombin III complex (TAT), and prothrombin fragment 1 + 2 (F1+2) were assayed. The time to clot onset was measured by force onset time (FOT). Platelet contractile force (PCF) measured the force produced by platelets during clot retraction, whereas clot rigidity was measured as clot elastic modulus (CEM). FOT, CEM, and PCF were measured by Hemodyne. Both groups had upregulation of the TF pathway, as TF, TAT, and F1+2 levels were similarly increased over baseline levels. Hemodialysis patients with frequent AVG clotting had higher levels of both PCF and CEM compared with nonclotters. Additionally, the frequent clotters had a lower FOT relative to nonclotters, although both were considered in the normal range. Our study suggests that HD patients with recurrent AVG thrombotic events form clots with higher tensile strength compared with HD patients without recurrent graft thrombosis. 相似文献
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Ward Vanlaar Robyn Robertson Kyla Marcoux Daniel Mayhew Steve Brown Paul Boase 《Accident; analysis and prevention》2012
While a general decreasing trend in the number of persons killed in a traffic crash involving a drinking driver has occurred in Canada since the 1980s, it is evident that much of this decrease occurred in the 1990s. Since 2002, less progress has been made as the number of persons killed in crashes involving drinking drivers remains high. To better understand the current situation, this paper describes trends in drinking and driving in Canada from 1998 to 2011 using multiple indicators based on data collected for the Traffic Injury Research Foundation's (TIRF) Road Safety Monitor (RSM), the National Opinion Poll on Drinking and Driving, and trends in alcohol-related crashes based on data collected for TIRF's national Fatality Database in Canada. There has been a continued and consistent decrease in the number of fatalities involving a drinking driver in Canada. This remains true when looking at the number of fatalities involving a drinking driver per 100,000 population and per 100,000 licensed drivers. This decreasing trend is also still apparent when considering the percentage of persons killed in a traffic crash in Canada involving a drinking driver although less pronounced. Data from the RSM further show that the percentage of those who reported driving after they thought they were over the legal limit has also declined. However, regardless of the apparent decreasing trend in drinking driving fatalities and behaviour, reductions have been relatively modest, and fatalities in crashes involving drivers who have consumed alcohol remain high at unacceptable levels. 相似文献
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Kamlesh Goel 《Scientometrics》2002,55(2):243-258
An analysis of gender differences in psychology in India provides quantitative and qualitative assessment of R&D output contributed by psychologists with the indication of the trend of growth, skewness, relatedness, co-authorship pattern of productivity. 相似文献
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References: 《中国标准化(英文版)》2007,(3):22-27
China has begun its standardization process in the cultural heritage since 1960.The standards contributed a lot to the development of the heritage conservation practices. In this paper, the author summaries the existing condition of standardization in the cultural heritages and museums field in China, and presents Standards for the Classification of Collected Cultural Heritages. Also this paper points out the problems which exist in the standardization in the cultural heritage, and gives the advice to solve these problems. 相似文献