起爆方式对间隔装药应力场分布及裂纹扩展的影响

通过模型实验研究了不同起爆方式对空气间隔装药炮孔两侧损伤分布的影响规律,借助数字图像相关实验系统,获取了全场应变场演化过程及空气段应变衰减规律,同时借助透射式焦散线实验系统,探究了起爆方式对预制裂纹动态断裂行为的影响.实验结果表明：柱状药包炮孔两侧产生的损伤范围具有显著的分形特征.采用外侧起爆时,空气段中心两侧均产生损伤,而采用其他起爆方式时,空气段均未出现损伤.不同起爆方式对空气段应变场径向压应变的影响主要体现在应变大小、衰减速度两个方面,对轴向拉应变的影响主要体现在时效性、衰减速度两个方面.不同起爆方式下预制裂纹端部断裂行为差别较大.采用内侧起爆、外侧起爆时,裂纹均为水平扩展,呈现典型Ⅰ型裂纹,裂纹起裂主要由拉伸破坏引起,异侧起爆时裂纹起裂为Ⅰ-Ⅱ混合型,具体表现为拉-剪破坏.基于数值模拟软件LS-DYNA,解释了预制裂纹端部起裂成因,得到了孔壁处应力场分布规律,不同起爆方式对炮孔轴向孔壁处压力分布影响显著,装药段主要体现在压力峰值位置和压力分布形态两个方面,空气段主要体现在压力峰值大小和压力分布形态两个方面.     

StimGun复合射孔技术的应用

随着油井勘探开发的深入,低孔、低渗、致密岩性的非常规油气层在油气储量中占较大的比例,由于其储层性质差,勘探开发难度大,采用常规射孔很难取得理想的效果.StimGun复合射孔技术是在射孔枪起爆后,推进剂燃烧产生高能气体,高能气体进入射孔孔道并在射孔孔眼周围形成多径向裂缝,从而沟通了天然裂缝,改善了油气流动通道,提高渗流能力.介绍了该技术的工作原理和技术优势,并通过现场试验、总结和完善,形成了一套满足于不同地质条件的、集安全施工设计和作业效果评价为一体的stimgun复合射孔技术.该技术成功应用于四川LG区块的射孔作业中,能有效的控制裂缝高度,达到清楚地层污染而又不出水的效果,对地透气性地层具有较好的改造作用,取得较好的作业效果.     

逐孔起爆技术及其应用

随着高精度毫秒导爆管雷管的出现，逐孔起爆技术得以实现。文中介绍了以降低爆破振动和破碎块度为目的的逐孔起爆技术，分析了逐孔起爆机理、起爆方式、网络设计及合理微差间隔时间的确定方法，并将该技术应用于露天矿山台阶爆破中，取得了预期的效果。最后探讨了该技术的应用前景和进一步的研究方向，为逐孔起爆技术在我国露天矿山的进一步推广应用提供了理论指导。     

中深孔凿岩逐孔爆破技术在那林金矿的试验研究

中国岩金地下开采矿山逐孔起爆技术应用不多.详述了逐孔起爆微差时间间隔和起爆网络的选择及设计,介绍了那林金矿逐孔微差爆破工程试验与实践.试验研究结果表明,中深孔逐孔爆破技术能够有效地降低爆破震动,改善爆破效果和提高爆破的安全性.     

气力输送技术在重有色冶炼中的应用

气力输送技术具有高效、节能、环保等优点,被广泛用于化工、饲料输送、钢铁、冶金等行业中的粉尘、颗粒物料的输送.阐述了气力输送技术的工作原理;输送方式的分类:即负压吸送式气力输送和正压压送式气力输送;输送方式的选择需要根据实际工艺要求、输送能力、物料性质、输送距离等参数来确定.重点对气力输送技术在重有色冶金行业中的应用进行了评述,气力输送技术较早应用于锌精矿输送,通过技术改进后成功将气力输送技术应用于ISP烧结烟尘的输送,针对闪速炼铜工艺中物料的性质,提出了合适的输送方式,为铜冶炼厂粉料输送技术的设计和选择提供了参考.随着气力输送技术的研究与应用不断取得进步,在重有色冶炼行业的应用也将越来越广泛,效果越来越显著.      

中深孔起爆药包位置对眉线的影响研究

对孔底、孔口起爆破碎机理进行了分析,通过对前期大量收集的不同起爆方式对眉线影响的数据进行统计分析,并根据梅山铁矿现阶段中深孔爆破起爆药包位置对不同岩石结构下的眉线影响进行归纳总结,对不同药包位置对眉线的影响给出了合理的解释。     

高精度导爆管及逐孔降震控制爆破技术在歌乐山石灰石矿的应用

介绍了逐孔起爆技术优势及歌乐山矿应用逐孔起爆技术及Orica管的情况通过比较表明逐孔起爆技术能极大改善爆破效果,降低爆破振动,降低采矿综合成本,提高矿山安全作业水平。     

两种起爆方法在七宝山矿的应用比较

通过采用导爆索起爆法和非电导爆管起爆法两次深孔爆破试验,并对这两种爆破方法的技术经济指标和优缺点进行比较,得出非电导爆管起爆法无论在技术经济指标方面,还是在爆破效果方面均比导爆索起爆法优越的结论.试验结果为非电导爆管起爆法在七宝山铁矿的全面推广奠定了基础.     

小型露天矿台阶深孔爆破几种起爆方式的探讨

如何选择恰当的台阶深孔爆破起爆方式,以减少爆破大块率和提高爆堆松散系数,对于提高小型挖掘机的挖掘效率显得尤为重要.本文就生产实践中几种起爆方式带来的爆破效果作一探讨.     

试论孔底起爆技术在镜铁山矿的应用问题

1导论孔底起爆技术，是近年来在我国地下金属矿山中深孔爆破中发展起来的一项新形应用技术。这种起爆方法能够充分利用炸药释放出来的能量，使之有效地作用于矿石破碎。自从六十年代中期地下矿山使用风动机械装药设备以来，地下采矿中深孔爆破一直延用沿全炮孔敷设导爆索、或者在孔内装药结束之后安设起爆药包，从孔日起爆向孔内深部传爆的爆破方式。这种传统的装药结构，炸药爆破作用差，成本费用高，是对采矿工艺各项技术经济指标造成较大影响的重要因素之一。炸药爆炸破碎岩石是由于爆轰产物和爆炸应力波共同作用的结果，孔底起爆之所以…     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.