桩基孔内岩石爆破技术应用

施工中遇到的中风化岩石使得人工凿孔施工进度缓慢,施工成本增加。采用小孔埋置炸药爆破方法,通过对工程环境、岩石爆破技术中的炸药量、预埋炸药炮孔位置、一次起爆最大药量等因素的控制,使得爆破工作安全顺利完成,很好地解决了施工难题,加快了进度并降低了成本,桩长也达到设计要求。     

深覆盖非均质复杂结构围堰拆除爆破设计

官地水电站尾水出口围堰具有深覆盖、非均质、卸荷基岩、堰体结构复杂的特点,围堰距离出口闸门及启闭机距离≤30m,闸室与围堰间明渠底板为1:4倒坡,明渠结构混凝土与围堰相接,与对岸拌合楼距离≤90m,爆破拆除规模大、要求高。介绍了该围堰爆破的方案选择、参数及起爆网路设计,爆破安全防护和施工技术措施,可供类似工程参考。     

联络道爆破施工对临近盾构隧道的影响分析

针对盾构隧道间联络道爆破开挖影响隧道稳定性的问题,通过数值模拟建立联络道与隧道管片的数值模型,以联络道掌子面与隧道间不同距离L作为研究工况,获取不同爆破位置对隧道管片稳定性的影响。通过模拟可知,当联络道掌子面与管片距离L为0时,盾构隧道管片是极不稳定的。以盾构隧道管片连接螺栓的屈服强度作为临界值,通过建立螺栓应力与距离L的关系,得到当L不小于1.43 m时,螺栓所受到的应力不大于其屈服强度,而分析管片间相对位移与L的关系,得到管片间的最大相对位移为2.88 mm。由此可知此时盾构隧道管片是安全的。通过对隧道爆破振动进行监测,得到了当安全距离为1.43 m时爆心距为3 m的监测点的最大振速为37.09 m/s,此数据虽然超过了爆破安全规定,但螺栓强度和管片位移都符合安全规程要求,施工质量可以得到保证,隧道仍然安全稳定。     

水介质不偶合装药破碎大块的研究

为了解决露天二次爆破的安全技术问题,我矿进行了水介质不偶合装药结构控制爆破的研究。试验证明:效果良好,爆破块度均匀合格;飞石距离控制在10米以内,安全可靠;烟尘少、爆声小;炸药单耗低;经济效益高;工艺简单,便于推广应用。     

复杂环境下楼房深基坑岩石控制爆破安全技术

为提高爆破施工安全,严格控制爆破振动和飞石,设计了某小区楼房深基坑岩石控制爆破方案,对比三种爆破方案,优选了其中一种方案。在施工过程中采用中深孔微差控制爆破,辅以浅孔施工;使用分段分区分台阶的爆破方法,其中控制爆破Ⅰ区、Ⅱ区、Ⅲ区钻孔深度分别为2.5 m、3 m、3.5 m,并于施工前进行爆破振动计算和施工过程中进行爆破振动的监测,监测区最大振动速度2.05 cm/s,最小振动速度1.16 cm/s,并根据测试结果对台阶高度、孔网参数和起爆规模进行调整。爆破施工结果表明:爆破网路参数安全可靠,爆破振动在安全允许范围内,无爆破飞石产生,提高了炸药能量利用率并改善了爆破效果,确保了爆破施工的安全。     

特殊环境下石场延时控制爆破开采技术

结合花岗岩石场开采爆破实践,介绍了在特殊环境下,利用间隔装药结构和使用普通毫秒导爆管雷管,直接控制炮孔起爆的毫秒延时爆破技术,以及在深孔爆破对有害效应进行控制的相关技术方法和参数。当炮孔深度h≤20m时,采用一层间隔,分两段装药;炮孔深度大于20m,小于25m时,采用两层间隔,分三段装药,孔间间隔时间Δt=100~125ms。在爆区采用"一钻到底"的钻爆施工方式,一次爆破用药量≤2 000kg;根据距爆区最近距离为60m的情况,确定最大单响起爆药量为79.7kg。为在当前电子雷管单价相对较高的情况下,运用普通毫秒导爆管雷管实现毫秒延时爆破、保障爆破安全、改善爆破效果、降低爆破成本等,提供了一种有益的参考。     

义海木里露天煤矿冻土爆破实验研究

为确定适用于义海木里露天煤矿地区的冻土爆破参数,采用现场实验的方法,研究了钻孔设备的选择、炮孔防护方法、起爆器材和炸药的爆炸性能以及爆破参数之间的关系等。结果表明:钻孔设备宜选用阿特拉斯D9钻机或更先进的钻机;利用PVC管做防护器材,炮孔利用率提高20%以上;导爆管应提前泄压才能在高原环境下使用;采用药壶爆破实验评估炸药爆炸性能,结果显示乳化炸药的作功能力强于铵油炸药。得出适用于义海木里煤矿地区的冻土爆破参数:孔径为80~120mm,孔深不大于6m,孔距和排距的组合取(4~5)m×(2.5~3.5)m,炸药单耗为0.28~0.3kg/m~3,底盘抵抗线不宜超过2.8m,采用斜线起爆网路。     

复杂地质下圆弧形边坡控制爆破的应用研究

为了研究复杂地质下如何将圆弧形边坡控制爆破一次成型,通过现场高陡边坡的爆破施工,介绍了圆弧形边坡控制爆破的设计原则、爆破参数及爆后效果：采用理论计算与现场施工相结合的方法,优化爆破参数,主炮孔采用现场混装乳化炸药进行装药,预裂孔采用分段不耦合装药,爆破后边坡上的半孔率达到90%以上,台阶高程偏差值不超过±300 mm,坡率偏差值不超过±0.5°。不仅节省了成本,又达到了边坡美观、整洁、稳定的设计要求,可为类似工程的边坡控制爆破提供参考。     

特殊环境下石场延时控制爆破开采技术

结合花岗岩石场开采爆破实践,介绍了在特殊环境下,利用间隔装药结构和使用普通毫秒导爆管雷管,直接控制炮孔起爆的毫秒延时爆破技术,以及在深孔爆破对有害效应进行控制的相关技术方法和参数。当炮孔深度h≤20m时,采用一层间隔,分两段装药;炮孔深度大于20m,小于25m时,采用两层间隔,分三段装药,孔间间隔时间Δt=100¹25ms。在爆区采用"一钻到底"的钻爆施工方式,一次爆破用药量≤2 000kg;根据距爆区最近距离为60m的情况,确定最大单响起爆药量为79.7kg。为在当前电子雷管单价相对较高的情况下,运用普通毫秒导爆管雷管实现毫秒延时爆破、保障爆破安全、改善爆破效果、降低爆破成本等,提供了一种有益的参考。     

深水海底沟槽爆破开挖技术

介绍了在水下岩石爆破开挖管沟沟槽施工技术。爆破开挖长度为2588m,最大爆破水深达到51m,施工区域条件恶劣,浪高达2~3m,流速达到2m/s。通过改造爆破施工船只、改进爆破器材、优化爆破参数和改进施工工艺等手段,达到了爆破施工要求。该工程是我国目前最深的水下钻孔爆破,为今后类似工程提供了参考与借鉴。     

Flow-Induced Instabilities in Pump-Turbines in China

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.     

Differences in coagulation in clotting of vascular access in hemodialysis patients

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.     

Trends in alcohol-impaired driving in Canada

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.     

Gender differences in publication productivity in psychology in India

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.     

离子液体中电沉积的研究进展

离子液体作为绿色溶剂和可设计性溶剂越来越受到重视.对电沉积来说,离子液体融合了高温熔盐和水溶液的优点.分别综述了AlCl3型离子液体、非AlCl3型离子液体和其他新型离子液体3类离子液体中电沉积的研究现状,在此基础上指出了目前尚存在的问题及今后的研究方向.采用离子液体进行电沉积能克服传统水溶液电沉积时存在的缺点,为电沉积领域找到了新的突破点,是一种很有应用前景的方法.     

高聚物银纹化的研究进展

结合最新的研究进展,对银纹引发、生长与断裂,银纹细观结构以及裂纹在银纹中的扩展等问题作了较全面的介绍和分析,对这一领域未来的研究方向和重点进行了展望。     

铁电陶瓷中电畴翻转研究进展

电畴为铁电陶瓷固有的独特微观组织特征之一,铁电陶瓷的许多性能均与其密切有关.综述了铁电陶瓷中的电畴结构,系统介绍了电场、机械作用引起的电畴翻转,概述了电畴翻转对铁电陶瓷断裂韧性的影响及其研究进展.     

Standardization in the Cultural Heritage in China

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.