共查询到20条相似文献,搜索用时 62 毫秒
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针对炼油、石油化工工程建设行业,特别是装置停工检修或抢修施工中,作业时间的紧迫性,通过对Demag AC-350型350t汽车式起重机在7级风状态下进行起重吊装作业的稳定性验算,提出在风力达6级或以上时进行吊机吊装作业是否可行的问题探讨。 相似文献
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起重机的臂架多是由众多杆件组成的桁架结构,其往往具有很高的强度,但是刚度及稳定性问题日益突出。基于设计规范的稳定性分析无法计算结构临界屈曲稳定载荷情况,可应用有限元法对臂架进行屈曲分析,得到臂架失稳时的临界载荷,为臂架的设计及校核提供参考。 相似文献
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1 前言随着石油化工装置规模发展的大型化,装置中的重型设备越来越多,而且随着运输能力的提高,超长超重设备可以整体进入安装现场。为适应我国石化装置设备大型化的需要,我公司引进了先进的液压提升技术,开发和制造了国际领先、国内独有的2500t/100m的门式液压吊装系统,填补了国内空白。 相似文献
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P. A. Levin 《Glass and Ceramics》1968,25(3):182-184
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1 概况随着石油化工、电力建设等装置向大型化发展,装置中的设备规格和重量也大幅度提高。以60万t/a乙烯装置为例,单件重量在100t以上的设备约有20台件,最重件达700~800t。因而特大型吊车的研制发展迅速。然而,仅靠这种常规的大型吊车仍难以满足各 相似文献
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汽车尾气净化三效催化剂的合成与性能 总被引:2,自引:0,他引:2
为开发新的尾气净化催化剂,运用改进的柠檬酸络合自燃法合成出单一晶相的B位双掺杂类钙钛矿化合物La4BaCu4Co0.5Ni0.5O13+8,根据DTA—TG测试确定了材料的最佳热处理温度为800℃,并通过XRD和SEM等对材料的物相结构和显微形貌进行了基本的分析,结果显示800℃时所制备的材料为单一类钙钛矿结构,其晶相为正交晶系,颗粒分布均匀;对材料的汽车尾气净化三效催化活性进行了测试,结果表明所制备的材料具有良好的尾气净化三效催化性能,当空燃比(空气与燃料的比值,下同)为14.6时,其对一氧化碳、碳氢化合物和氮的氧化物的催化转化效率分别达到了97%,82%和88%。 相似文献
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Martin J. T. Reaney Nancy J. Tyler Keith Brown 《Journal of the American Oil Chemists' Society》1999,76(7):859-862
If proton nuclear magnetic resonance (NMR) spectra of single seeds can be improved, a rapid, low-cost method of screening
seeds for oil composition could be developed for use as a selection tool in plant breeding. NMR spectroscopy was performed
on single seeds of borage, flax, and canola to evaluate methods for improving spectra quality (narrowing peak widths and increasing
signal-to-noise ratio) to a degree necessary to measure differences among seeds in a breeding program. Immersion of seeds
in a variety of solvents, including deuterated chloroform, deuterated acetone, deuterated dimethyl sulfoxide (DMSO) and completely
fluorinated hydrocarbons (FC-77), narrowed peaks obtained from seeds when compared with spectra from seeds analyzed in the
absence of a solvent. Deuterated chloroform and FC-77 were free of interfering solvent proton peaks while deuterated acetone
and deuterated DMSO contributed interfering peaks. The spectra of dehulled seeds had narrower peak widths than did seeds with
hulls. Treatments that decreased seed oil viscosity failed to substantially narrow spectra peak widths of seeds. High magnetic
field strength did not improve the spectral quality of seeds, as peak widths increased with field strength. Conversely, low
field strength limited resolution of oil spectra. Although the 300 MHz spectrum of vegetable oil had greater resolution (narrower
peaks) than the 60 MHz spectrum, spectra of seeds produced at 60 MHz had superior resolution to 300 MHz spectra. 相似文献
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The effects of moisture content, age, growing location, and genotype of flaxseed on the efficiency of pressure extraction
of oil, when extracted in a Carver press cylinder, were examined. Decreasing the seed moisture content from 7.8% to 2.3% increased
the proportion of oil extracted from 31.4% to 49.6%, respectively. Oil was more difficult to extract as the age of the seed
increased. The proportion of the total oil extracted varied from 25.0% to 41.4% depending upon the location where the seed
was grown. The effect of genotype was less pronounced, ranging from a mean of 46.9% in Redwing to 54.2% in Redwood 65 for
samples analyzed at normal storage moisture. Samples with high oil contents usually yielded the highest proportion of total
oil recovered (r=0.893**, 9 df).
Contribution No. 153, Morden Research Station. 相似文献
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在硝铵类炸药相关的生产、管理过程中,最小点火压力(MBP)已经成为重要的安全参数。工业炸药中硝酸铵常常与油相混合,为了研究混油硝酸铵在生产、储存及运输中的安全性,运用MBP值对其进行安全评估。使用热丝点火的方法探究温度及油含量对硝铵类炸药MBP值的影响。常温下对油含量为0~10%的11组样品进行测量,样品的MBP值从大于6 MPa,不断降低至1.59 MPa。并在20、75、100℃下分别对不同油含量的样品进行MBP值测量,油含量为4%、6%、8%、10%样品的MBP值分别从2.25、2.01、1.75、1.59 MPa降低至1.51、1.05、0.41、0.21 MPa。实验结果表明,常温下,混油硝酸铵样品的MBP值随油含量的升高而降低;控制样品的组分不变,得到样品在不同初始温度下的MBP值,则温度升高,混油硝酸铵的MBP值有明显的降低趋势。 相似文献