共查询到20条相似文献,搜索用时 140 毫秒
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齐化公司炼油厂针对ARGG装置存在的问题,采取了相应改造措施,提高了轻质油产率,保证了装置安稳运行,降低了催化剂单耗和装置能耗,提高了装置的经济效益。 相似文献
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随着加氢装置的广泛应用,氢气系统的管理与优化成为节能降本增效的有效手段。本文以胜利石化制氢装置为例,详细介绍了原料优化操作降低装置压降,提高装置处理量,提高氢气回收率等工艺优化,有效降低了制氢成本、提高了经济效益,为同类型制氢装置优化原料配比提供了参考。 相似文献
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对抚顺乙烯裂解装置自开车以来历年主要技术改造进行了总结.通过技术改造,乙烯装置产能得到提高,装置各项经济技术指标不断完善和提高,保持了装置的长期安全稳定运行. 相似文献
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介绍合成氨装置配套煤棒装置生产流程,分析了犁式卸料器、料仓远程控制器等存在的问题。卸料方式经改造后,采用布料小车卸料;对远程控制系统的精确性进行了改造,提高了合成氨装置皮带卸料器装置的适应性,并提高了装置的自动化水平。 相似文献
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探讨了催化裂化装置油浆换热系统改造,通过对流程的优化,进一步实现了装置之间的热联合,降低了装置的总能耗,提高了装置的操作稳定性。 相似文献
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分析和介绍了国内外催化裂化装置建模和稳态模拟方面的研究和进展。对催化裂化反应集总方法及相应的反应网络进行归纳,并讨论其优缺点;推导了动力学模型方程并着重探讨方程求解算法以及模型中动力学参数、催化剂失活因子和装置因素的估计方法。 相似文献
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详细阐述了金属腐蚀的危害机理,分析了影响数控机床腐蚀的因素,介绍了防腐涂料及防腐技术在数控机床上的应用现状,提出了数控机床整机防腐的对策及防锈措施。 相似文献
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主要介绍高精度塑料零件的选材要求,研究塑料切削加工的特点,针对影响塑料切削加工质量的因素提出了具体的对策及经实践验证可改善和提高塑料切削加工质量的方法,探讨了铣切加工高精度塑料零件时的铣切工艺、铣切刀具和加工参数的选择原则。 相似文献
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Albert Erkip 《Polymer》2004,45(2):641-648
The fluctuations of residues of proteins about their equilibrium configurations are analyzed by the Langevin equation. Residue pairs that are covalently bonded and those that are within a given cutoff distance of each other are assumed to be connected by linear springs. The actions of the solvent and intramolecular interactions on each residue are treated as random noise. The correlations of fluctuations resulting from the solution of the Langevin equation are observed to be identical to those obtained by the Gaussian Network Model based on equilibrium statistical mechanics. The time-delayed correlations of fluctuations, and the response of the protein to a given frequency and to a window of frequencies are determined. The fluctuations of the residues resulting from a given fixed externally applied frequency are evaluated for different modes of the system. Synchronous and asynchronous components of correlations for different modes are formulated. The findings of the present paper are applied to the 241 residue protein S. marcescens endonuclease (1QL0). 相似文献
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以平顶山煤和徐州煤为原料,利用回收NMP与CS_2混合溶剂和反萃取剂将两种煤全组分分离成萃余煤组分、沥青质组分、精煤组分和轻质组分四大族组分,主要对比原煤及各族组分的真密度、工业分析与元素分析。结果表明,萃余煤组分真密度最大,分别为1.59和1.45,精煤组分与沥青质组分真密度低于原煤。轻质组分具有较多非共价键成键点,易与水分子形成氢键,水分含量最高,分别为6.09%和5.77%,而萃余煤组分水分含量最低,分别为0.96%和0.63%。沥青质组分接近无灰。挥发分含量以轻质组分沥青质组分精煤组分原煤萃余煤组分顺序降低。C元素含量以精煤组分与沥青质组分相对较高,萃余煤组分C元素含量较两者偏低,分别为80.91%和80.65%。轻质组分中N、O和S元素含量较高,C元素含量最低。 相似文献
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A freeze-drying procedure is developed for manufacturing silver nanopowder with regular shape and uniform diameter. The procedure includes four steps: preparing the precursor solution, freezing the solution, drying the congelation, and calcining the drying product. The starting substances are silver nitrate and caustic soda and the precursor is diammine silver solution. Three freezing styles including direct freezing, vacuum evaporation freezing, and spray freezing are adopted to freeze the precursor solution. In the drying stage, two heating styles for the frozen solution are compared. X-ray diffraction (XRD) and energy disperse spectroscopy (EDS) spectrograms show that the products of freeze drying are pure amorphous silver nanopowder without hard agglomerations. Silver cubic nanocrystals are subsequently obtained by calcination. The chemical fundamentals and the drying curves of freeze drying are given. The processes of preparing silver nanopowder are described in detail. The effect of freezing and heating on characteristics of the powder are discussed. The mechanism of grain forming and growing up is analyzed according to the observation results. The characteristics of powder freeze drying and its feasibility for volume production are presented. 相似文献
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分光光度法测定天然多酚类化合物含量的研究进展 总被引:1,自引:0,他引:1
介绍了近年来分光光度法在测定天然多酚类化合物方面的研究进展。综述了测定天然多酚类化合物方法的应用范围,对测定方法按化学反应进行分类,如络合反应、氧化还原反应、亲核加成反应和重氮化-偶合反应等,并探讨了测定方法的反应原理及测定方法中存在的问题,对今后的研究方向作了展望。 相似文献