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1.
一种自焙炭块的显色孔率和体积密度   总被引:1,自引:1,他引:0  
采用浸渍法测定了具有不同石墨化率自焙炭块的体积密度和量气孔率,并与其它炭块进行了比较,结果表明:在实验温度范围内体积密度和显气孔率基本不随温度变化;在恒温时间内,二者基本与恒温时间无关,据实验结果,讨论了不同条件下自焙炭块的电阻率与温度和时间的关系。  相似文献   

2.
采用浸渍法测定了具有不同石墨化率自焙炭块的体积密度和显气孔率,并与其它炭块进行了比较.结果表明:在实验温度范围内体积密度和显气孔率基本不随温度变化;在恒温时间内,二者基本与恒温时间无关.据实验结果,讨论了不同条件下自焙炭块的电阻率与温度和时间的关系.  相似文献   

3.
通过对高炉炉缸黏滞层化学成分分析、XRD、SEM-EDS分析及对炉缸用碳复合砖性能、微观结构的研究,探明了炉缸黏滞层的形成机理.结果表明:碳复合砖本身致密的微观结构使其具有优良的抗渣铁侵蚀性能,且具备自护炉机制,能够形成石墨-C层、高铝渣层、石墨层多相体系.并通过计算得出高炉炉缸侧壁石墨碳析出热力学条件,表明在一定的铁水流动条件下,石墨碳与铁水存在溶解析出平衡,从而隔离开铁水与砖衬的直接接触,延缓砖衬侵蚀,实现高炉炉缸长寿.  相似文献   

4.
测定了高炉用自焙碳砖在其自焙烧过程中,导热系数随时间变化规律及其它物理性质·结果表明,自焙碳砖自焙烧过程中导热系数λ与焙烧时间τ可表示为λ=38345+000143τ·结合鞍钢7#高炉生产数据,建立了自焙碳砖 陶瓷砌体非稳态热传导的数学模型,并采用数值分析方法对该模型进行了分析求解·其结果表明该模型与实际生产情况比较吻合,除炉底中心部位之外,炉缸耐火材料内衬800℃以上等温线随自焙碳砖石墨化程度的提高逐渐上移至陶瓷砌体层内,从温度场分布角度上看,新型炉缸结构将消除传统结构炉缸所存在弊端,有助于高炉长寿·  相似文献   

5.
高炉炉缸炭砖脆化层的形成是危及高炉寿命的重要原因之一。调查表明,脆化层处于环裂缝外侧,环裂缝与热面间炭砖结构致密。脆化层中渗铁量低、孔隙度高、灰分未增加、碳结构的晶面距小。研究指出,脆化层是由于炭砖中的沥青粘结剂炭化后的炭框架氧化所致。为提高炭质耐火材料质量,除采用高温煅烧无烟煤,改进生产工艺外,应开发新型粘结剂。  相似文献   

6.
对使用前后的高炉炉缸炉底炭砖进行了实验室分析研究,分别测定了炭砖的透气度、微气孔分布指标,讨论了炭砖渗铁现象的形成原因。认为炭砖渗铁是高炉炭砖炉缸炉底形成异常侵蚀的一个重要原因。  相似文献   

7.
采用X射线衍射方法测定了具有不同石墨化率的自焙炭块的真密度ρu,并结合体积质量ρb估算了全气孔率q和比孔体积V·同时采用EPM方法观测了自焙炭块的气孔形态,并与美国UCAR NMA系列炭块进行了比较,认为:国产自焙炭块的气孔形状及力学结构不尽合理;1450℃下铁液在该炭块孔隙中的渗透较明显,且随时间的延续,渗透深度增加·  相似文献   

8.
介绍了硅铁电炉原炉衬结构、使用中存在的主要问题及原因 ,论述了自焙炭砖炉衬结构、特点和使用效果  相似文献   

9.
将沥青与天然石墨球按不同比例混合,经碳化处理后再进行石墨化得到锂离子电池用复合炭负极材料。研究结果表明:复合炭材料具有较大的平均层间距d002;复合炭材料仍保持类球形形貌;复合炭材料在较大倍率下的循环性能优于天然石墨球,其中在沥青基人造石墨与天然石墨球的质量比为15%的条件下,0.1C(1C=300 mA/g)充放电电流下材料的可逆比容量为343.7 mA·h/g,首次库仑效率为85.4%,1C下可逆比容量为295.4 mA·h/g,达到0.1C时可逆比容量的85.9%;1C倍率下50次循环比容量保持率为91.6%,与天然石墨球相比,复合材料具有更大的锂离子扩散系数。  相似文献   

10.
粘结剂炭的结构与抗氧化性   总被引:2,自引:0,他引:2  
研究了中间相沥青和酚醛树脂粘结剂及其热解炭的抗氧化性,通过X-ray衍射,扫描电镜,粘结剂残炭率及炭真密度测定,综合评价中间相沥青用作镁炭砖粘结剂的可行性,结果表明,中间相沥青的抗氧化明显优于酚醛树脂,中间相沥青炭结构致密,有取向性,呈石墨化炭结构,而酚醛树脂质炭结构疏松,无取向性,呈难石墨化炭结构,中间相沥青残炭率为65.53%,炭真密度为1.91g/cm^3,酚醛树脂残炭率为49.40%,炭真密度为1.73g/cm^3,可以看出,粘结剂炭的抗氧化性取决于它的显微结构。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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