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《中南大学学报(自然科学版)》2015,(12)
在260℃高压溶出黄铁矿制备高硫高铁的铝酸钠溶液,研究溶液温度、保温时间、苛性比(αk)以及Na_2CO_3,Na_2SO_4和Na_2C_2O_4等杂质对溶出液中铁质量浓度的影响。研究结果表明:溶液温度为50℃和60℃时,随着保温时间的延长,溶液中铁质量浓度略有降低;苛性比为3.0左右时,随着Na_2CO_3质量浓度的升高,溶液中铁质量浓度略有升高,而Na_2SO_4和Na_2C_2O_4质量浓度的升高则能显著提高溶液中的铁质量浓度;随着溶液苛性比的升高,溶液中铁质量浓度在苛性比为2.0~2.5之间有1个急剧升高的区间,然后逐渐趋于稳定。 相似文献
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苛性比对铝酸钠溶液结构和性质的影响 总被引:4,自引:0,他引:4
用红外光谱和粘度测定手段考察了苛性比对铝酸钠溶液结构和性质的影响·发现在中等浓度以上的铝酸钠溶液中,当ρAl2O3不变时,随着苛性比的增加Al O Al峰减弱至消失;Al(OH)-4的峰减弱·温度在70℃以下,铝酸钠溶液的粘度随苛性比增加而大幅度增加,高于70℃增加较小·用铝酸钠溶液中铝酸根阴离子与OH-形成缔合物解释铝酸钠溶液的红外光谱和粘度随苛性比的变化· 相似文献
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提高氧化铝种分率的研究 总被引:1,自引:1,他引:0
陈肖虎 《贵州工业大学学报(自然科学版)》1999,28(5):42-44
对影响拜耳法种分分解率的各主要因素,精液苛性比αk溶液Al2O3浓度CA、晶种系数及加入方法,分解温度和降温制度进行了分析论证,并提出改善这些 有效途径。 相似文献
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研究了1,6-二磷酸果糖溶液在不同酒精浓度和pH下的溶解度以及不同1,6-二磷酸果糖溶液的浓度、温度及pH下的粘度,并给出了浓度对粘度的关联式.实验发现,溶液的温度和pH对溶液的粘度有很大的影响,因此升高溶液的温度和降低溶液的pH有利于改善溶液的传质状况和结晶条件,为1,6-二磷酸果糖的结晶新体系的研究提供依据. 相似文献
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铝酸钠溶液中二氧化硅的平衡浓度 总被引:9,自引:0,他引:9
基于组成类似的化合物热力学数据与组成存在的线性关系,计算了4种钠硅渣的热力学数据,并计算了在铝酸钠溶液中形成钠硅渣后二氧化硅平衡浓度与温度或苛性比的关系·计算结果表明,二氧化硅平衡浓度计算值与实验值相符;同时,随着温度的升高或苛性比的增大,铝酸钠溶液中二氧化硅平衡浓度也随之增大 相似文献
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《中南大学学报(自然科学版)》2020,(3)
通过合成高活性氢氧化铝净化铝酸钠溶液中的锂,考察不同反应条件对沉锂效果的影响,并对除锂反应机理进行研究。通过XRD和SEM分析,对沉锂产物进行表征。基于不同条件下沉锂率与反应时间的关系,构建Avrami动力学方程。研究结果表明:在苛性比α_k(即溶液中Na_2O_k与Al_2O_3物质的量比)为1.45的铝酸钠溶液中,控制温度为353 K,高活性氢氧化铝添加量为1.3 g/L,反应时间为120 min,沉锂率可达80.04%;高活性氢氧化铝与溶液中锂离子发生沉淀反应,其沉锂产物为Li_2Al_4(CO_3)(OH)_(12)·3H_2O;在348~363 K温度范围内,沉锂过程的表观活化能E_a=16.474 kJ/mol,指前因子A=160.355 min~(-1),速率常数k可以表示为k=160.355×e~((-16.474)/(RT))。 相似文献
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在热力学计算的基础上,研究CaCO3在铝酸钠溶液体系中发生反苛化反应的规律.热力学计算表明,低温条件下,CaCO3与游离苛性碱形成Ca(OH)2的反苛化程度较小,而其与Al(OH)4-形成3CaO·Al2Oy6H2O(C3AH6)的反苛化反应显著.CaCO3在纯NaOH溶液中反苛化反应的反应率小于5%,而在铝酸钠溶液中其反苛化率可达50%以上,说明Al(OH)4-对CaCO3的反苛化具有显著的促进作用;CaCO3的反苛化率随温度的升高而升高,随铝酸钠溶液苛性比αk的升高呈先升高后降低的规律,当αk为3时,出现极大值;常压条件下,CaCO3在铝酸钠溶液中发生反苛化反应形成C3AH6,而造成氧化铝损失. 相似文献
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以母液苛性比和结晶率为考察指标,对高铝粉煤灰水热法浸出液结晶铝酸钠的行为进行了研究.主要考察了Na 2 O浓度、结晶时间、结晶温度和晶种添加量对铝酸钠结晶的影响.结果表明,铝酸钠溶液中氧化钠浓度的升高和结晶时间的延长,有利于提高铝酸钠结晶率.但升高温度,会导致铝酸钠结晶率小幅下降.其次,研究还发现添加晶种能显著提高铝酸... 相似文献
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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
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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
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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
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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
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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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《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献
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《吉林大学学报(理学版)》2014,(5):1105
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has 相似文献