挖掘机斗杆断裂的力学分析

对挖掘机斗在不同工况条件下受力状况进行了分析，并通过测试，将１５ＭｎＶ和ＨＱ８０钢动态力学性能进行了对比，认为斗杆早期断是由所用材料的动态断裂特性所决定的，测试结果证明：ＨＱ８０钢抗脆断裂优于１５ＭｎＶ钢。     

JYL210E型轮胎式挖掘机底盘开裂的修复与加固

济钢第一炼钢厂JYL210E型轮胎式挖掘机工作700h后,出现大架撕裂、底盘裂纹现象,无法安全使用,对此进行修复加固。通过采取加固后桥、增加辅助钢板、焊补底盘和斗杆等措施,挖掘机整车强度提高了3.5倍、刚度增加了6倍,提高了使用性能和安全性能,节约采购资金200多万元。     

利用声发射测试断裂能

在通过无瑕木样本获取模式Ⅰ断裂能时,我们使用声频技术检测沿着顺纹进行的断裂增长.使用新技术估量声发射放出的能量,把能量与批量模式断裂能做一比较,可以使我们知道由断裂能转化为可测试声频能量的数量.该实验的结果说明大约有六分之一的断裂能可以做为声频能测量.     

热轧钢卷捆带断裂机理及其防治技术

针对热轧钢卷周向捆带出现的断裂问题,从捆带断裂机理分析入手,在分析了捆带断裂强度条件的基础上,建立了一套捆带断裂预报模型。首次提出了利用钢卷捆带断裂系数来表示热轧钢卷发生捆带断裂的概率的方法,从统计学的角度给出了钢卷捆带断裂的判断条件和捆带分档使用原则,开发出了相应的捆带断裂的防治技术并编制出了一套完整的捆带分档使用软件。将其推广应用到生产实践,取得了良好的使用效果,有效降低了热轧钢卷周向捆带断裂的发生率,给企业创造了较大的经济效益,具有进一步推广应用的价值。     

6 m焦炉炉门框焊接实践

介绍了石家庄焦化集团有限责任公司对断裂的焦炉炉门框进行的焊接试验,对断裂的6m焦炉炉门框进行的焊接使用结果表明,该焊接方案安全可靠、能够满足使用要求。     

锯链用钢51CrV4链片断裂原因分析及改进措施

针对合金弹簧钢51CrV4生产的锯链链片在使用后出现断裂现象,通过对其原材料、生产流程、断裂的链片等进行了全面分析。结果表明,链片断裂的主要原因是由于热处理工艺不合理,等温淬火后得到了塑韧性差、脆性大的马氏体组织。通过优化热处理工艺,得到更理想的硬度和塑韧性好的下贝氏体组织,在后续使用中未再出现链片断裂现象。     

螺纹吊杆断裂失效分析

为寻找螺纹吊杆断裂原因,使用扫描电镜和金相显微镜对试样进行分析.结果表明,该螺纹吊杆断裂属疲劳断裂,是组织未经调质处理和表面机加工粗糙等多种因素综合所致.     

手拉葫芦短环链断裂分析

采用20Mn2为原材料制作的手拉葫芦短环链在使用不到半年情况下,发生断裂事故.采用化学、金相、硬度及扫描电镜分析,发现断裂链条的理化指标均符合相关规定的要求,短环链断裂属韧性断裂,造成断裂的主要原因是:(1)链条存在机械损伤缺口;(2)链条曾受到局部过载应力.     

20MnSi螺纹钢筋冷弯成型断裂分析

鞍钢小型厂生产的20MnSi 螺纹钢筋,是冶金部优质产品,但在1975年上半年,我国某水电站使用φ28mm 螺纹钢筋冷弯成型时断裂。为分析断裂的原因,在试验室中取冷弯断裂和不断裂试样,进行对比分析。     

热镀锌钢绞线断丝原因分析

针对热镀锌钢绞线在生产及使用过程中断裂严重的情况,通过对断样进行分析,指出断裂原因,并提出相应的解决措施。     

2300XP电铲勺杆的矫正

2300XP电铲是德兴铜矿采矿重要设备,因服役年限很长等多方面原因,所有电铲勺杆均出现不同程度的变形,制约了电铲的效率。针对2300XP电铲勺杆实际变形情况,结合勺杆的材质,采用合理的工艺对变形的勺杆进行修复,将能直接影响修复后的勺杆实际使用寿命。通过反复实践,我们采用火焰矫正工艺,对弯曲的勺杆空腹梁进行变形矫正并取得了成功,对类视焊接结构件的修理有一定的借鉴作用。     

A Novel Heat Treatment for Excavator Dipper Teeth Manufactured from Low‐Carbon Low‐Alloy Steel

This research examined the metallurgy of production of forged excavator teeth manufactured from low‐carbon low alloy steel. A novel partial forging‐remnant‐heat hardening technology was proposed. The critical temperature of isothermal annealing for 40 Cr steel was determined experimentally to be 650°C. Production dipper teeth were produced using this novel technology. Their properties were compared with dipper teeth produced by the alternative routes. The novel technology provided optimum microstructure, good mechanical properties, and a lower economical cost, congruent with the low carbon economy.     

提高电铲采掘能力的探讨

分析阐述了影响电铲采掘能力的各个因素；郑重介绍了提高电铲采掘能力的主要途径和实践经验。     

露天矿电铲-汽车开采工艺中的铲、车匹配

本文着重阐述了露天矿设计中电铲一汽车开采工艺中影响铲、车匹配的因素,并总结了斗容比和铲、车比的计算公式及经验选值。     

液压扳手支撑手柄孔边应力集中三维有限元分析

对液压扳手手柄进行实体几何建模、力学建模、施加荷载和约束,利用三维空间有限元方法对手柄的孔边应力集中进行细致的研究,得到液压扳手各部位应力和变形的精确数值,找出孔边应力集中区域及其危险程度。为加强结构强度或减少冗余结构部分提供了有力的设计依据。     

Differential rearing conditions and alcohol-preferring rats: Consumption of and operant responding for ethanol.

Exposing rats to differential rearing conditions during early postweaning development has been shown to produce changes in a number of behaviors displayed during adulthood. The purpose of the present studies was to investigate whether rearing alcohol-preferring (P) and nonpreferring (NP) rats in an environmental enrichment condition (EC), a social condition (SC), or an impoverished condition (IC) would differentially affect self-administration of 10% ethanol. In Experiment 1, rats were tested for consumption of 10% ethanol in limited- and free-access tests. For Experiment 2, rats were trained to respond in an operant chamber for ethanol and then provided concurrent access to 10% ethanol and water. Each solution was presented in a separate liquid dipper after meeting the schedule of reinforcement on distinct levers. After concurrent access tests, the water lever/dipper was inactivated and a progressive ratio (PR) schedule was initiated. Three successive solutions (10% ethanol, 15% ethanol, and 10% sucrose) were tested under the PR. For P rats, rearing in an EC reduced ethanol consumption, preference, and motivation to obtain ethanol, relative to P rats reared in an IC. Thus, exposure to a novel environment immediately after weaning acted to decrease the reinforcing properties of ethanol in an animal model for alcoholism. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

判断锅炉风机故障的简易诊断技术

结合典型实例介绍了诊断锅炉风机等转动机械故障的基本分析方法和处理方法,亦即根据运行中故障风机主特征,通过听、看、摸、闻,去检查寻找设备运行中表面的其它现象,来确定故障部位、故障原因并及时处理,对专业技术人员和值班人员判断并防止扩大转机故障、减少损失、正确及时地处理故障具有现实指导意义。     

Cues for movement in monkeys (Macaca mulatta) with lesions in premotor cortex.

Previous studies by U. Halsband and the present author (see PA, Vol 69:570; see also 1985) showed that after removal of premotor cortex, monkeys were poor at selecting movements on the basis of a visual contextual cue. In those experiments, Ss had to pull or turn a handle depending on the color of a cue presented in the foreground or background. In the present 2 experiments, with 11 rhesus monkeys, Ss with lesions that included the premotor cortex could select movements correctly if the cue was given by information about the handle itself. In Exp I, the cue was provided by the direction in which the Ss had last moved the handle; Ss were required to squeeze a handle if they had been forced to squeeze it 5 sec earlier and to turn it if they had been forced to turn it. In Exp II, the cue was provided by the identity of the handle itself. When presented with a blue handle, Ss had to pull the handle; when presented with a yellow handle, they had to turn it. It is argued that animals with premotor lesions are impaired only when the task is a true conditional task. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new rodent model for neuroleptic-induced pseudo-Parkinsonism: Low doses of haloperidol increase forelimb tremor in the rat.

Rats were trained to use the right forelimb to exert continuous downward pressure on a force transducer and simultaneously to drink sweetened milk from a dipper controlled by the emitted force. Oscillations in forelimb force during this performance were spectrally analyzed to describe the tremorogenic effects of haloperidol (0.04, 0.08, or 0.16 mg/kg). Haloperidol reduced time-on-task and increased the variance of force oscillations in the 10.0–25.0 Hz frequency band. When atropine sulfate (5 mg/kg) was given along with haloperidol, time-on-task was partially restored, and the effects of haloperidol on the 10.0–25.0 Hz band were diminished. These data suggest that the behavioral deficits produced by relatively low doses of haloperidol in rats are analogous (and possibly homologous) to neuroleptic-induced Parkinsonian symptoms in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

结晶器热电偶的合理埋设及测试

讨论了结晶器热电偶合理的埋设方式,并提出了合理的测试方法及测试数据处理方案。