基于扩散偶法的CaO–V2O5和MnO2–V2O5固相界面反应行为比较

钒是我国重要的战略金属资源,广泛应用于钢铁、化工、航空航天等领域。钒渣作为我国最重要的含钒原料,其钙化提钒及锰化提钒工艺在钒的高效分离、尾渣利用和环境保护方面优势显著,但焙烧过程中钒酸钙和钒酸锰始终共存。两种钒酸盐的生成机理及钒与钙、锰反应能力的差异是两种提钒工艺的基本问题和共性问题,这对充实提钒基础理论和促进提钒工艺优化具有重要意义。为此,本文基于扩散偶研究方法,通过制备氧化钙–氧化钒和二氧化锰–氧化钒扩散偶,并在不同时间恒温焙烧,比较研究了钙、锰与钒组元固相反应的界面扩散行为差异;阐明了钒酸钙和钒酸锰的生成机理;进一步基于扫描电子显微镜和能谱分析研究并计算了扩散产物和扩散系数随焙烧时间的变化规律。结果表明,随着焙烧时间的延长,氧化钙–氧化钒、二氧化锰–氧化钒两组扩散反应逐渐进行。氧化钙–氧化钒扩散偶中钙和钒的分布区域边界始终清晰。而对于二氧化锰–氧化钒扩散偶而言,随着恒温焙烧时间的延长,二氧化锰逐渐分解生成三氧化二锰,钒组元能扩散到三氧化二锰内部,但仅有部分钒与锰反应形成扩散产物层。氧化钙–氧化钒、二氧化锰–氧化钒扩散偶的界面反应产物分别是偏钒酸钙和偏钒酸锰。恒温焙烧16 h后,产物厚度分别为39.85和32.13 μm,且由于组元扩散反应能力的限制,两个扩散偶均达到反应平衡。相同恒温焙烧时间内,氧化钙–氧化钒扩散偶的扩散系数略高于二氧化锰–氧化钒扩散偶,这说明钒与钙的扩散反应比钒与锰的扩散反应更易进行。     

宣钢竖炉球团矿强度变化规律

研究了宣钢球团矿在氧化焙烧过程中强度变化,为生产工艺可行性判断及工艺参数优化提供了理论依据.试验结果表明:球团矿氧化焙烧过程中存在影响其抗压强的最低焙烧温度和最高焙烧温度,只有在后者高于前者时,竖炉焙烧工艺才是可行的.     

难选菱铁矿流态化预氧化-低温还原磁化焙烧

磁化焙烧–弱磁选联合工艺是目前实现低品位难选铁矿高效铁资源富集利用的最有效工业化方案之一。菱铁矿（碳酸亚铁）和赤铁矿（三氧化二铁）是两种主要弱磁性难选含铁矿物,菱铁矿在常规工业化赤铁矿还原磁化焙烧条件下会生成弱磁性浮氏体,进而降低磁性物相转化率和最终弱磁选精矿铁元素收得率。对此,本文提出了菱铁矿流态化预氧化–低温还原的磁化焙烧高效物相转化方案,并以低品位陕西菱铁矿为样品进行了系统研究。研究发现,菱铁矿在快速预氧化过程中会生成弱磁性和强磁性三氧化二铁两种铁氧化物,其中强磁性三氧化二铁500–550℃还原焙烧产物除工艺目标物相强磁性四氧化三铁外,还有部分由不稳定四氧化三铁被进一步还原生成的弱磁性浮氏体。预氧化产物只有在更低温度还原焙烧才能实现目标四氧化三铁产物相的稳定存在,优化的菱铁矿流态化快速焙烧完全磁化转变工艺参数为610℃预氧化2.5 min再低温450℃还原焙烧5 min,菱铁矿经此条件磁化焙烧后磨矿弱磁选分离能够达到精矿铁含量62.0wt%、铁元素收得率88.36%的优良指标,相比常规直接还原焙烧铁元素收得率大幅提高34.33%,可以实现低品位难选菱铁矿的高效物相转化资源利用。本文提出的预氧化-低温还原焙烧方案也具有适用于菱铁矿–赤铁矿共伴生铁矿全范围含量比例共磁化焙烧的特点。     

两段焙烧强化含铼低品位钼精矿的氧化分离

针对氧化焙烧法处理低品位钼精矿中存在的钼氧化不完全、铼难挥发分离、有价元素(钼和铼)回收率较低等问题,采用焙烧试验、热重、物相和显微结构分析等研究两段焙烧强化氧化含铼低品位钼精矿中钼、铼的工艺及原理。研究结果表明:两段焙烧是实现钼、铼充分氧化的有效处理工艺。该工艺通过调节两段的温度和气流方向,改善气固对流条件,减小氧化焙烧过程的氧化差异,促进含钼和含铼矿物的深度氧化。在最佳工艺条件下(Ⅰ段焙烧温度675℃,焙烧时间1 h,气流由下至上;Ⅱ段焙烧温度625℃,焙烧时间2 h,气流由上至下),最终焙烧过程铼挥发率可达77.21%,焙烧产物中可溶钼质量分数提高到83.98%。相较于一段焙烧,两段焙烧各层产物的物相组成及微观结构一致,不存在未氧化的辉钼矿(MoS2)和氧化不完全的低价钼氧化物(MoO2),钼主要以MoO3形式存在。     

红色荧光粉YAlO3:Eu3+Cu+的制备和发光特性

研究了化学沉淀法制备YAP:Eu3+Cu+荧光粉,得到适宜工艺参数.用XRD和PL谱分别表征前驱体的晶体结构和荧光粉的荧光特性.前驱体的焙烧温度为1 200℃,焙烧时间为2 h;Eu3+的适宜掺杂浓度为3%,而且在398 nm紫外光激发下荧光粉呈现红色光谱,这是由于Eu3+的4fn电子组态内5D0→7FJ(J=0～4)的跃迁发射,由5D0→7F2的发射特性和发射强度表明Eu3+主要处于非反演对称中心.Cu+增强了YAP:Eu3+的发光强度是因为Cu+→Eu3+之间的能量传递,Cu+对Eu3+有敏化作用.     

压汞法表征铁矿球团固结程度

基于压汞法,定义了球团矿的氧化焙烧固结指数(OCI),并以其表征球团矿氧化焙烧固结程度.通过分析不同球团矿生球氧化焙烧过程中球团矿孔隙率及孔径大小的变化,计算球团焙烧固结指数.同时,对相应的成品球团矿的抗压强度进行测试.结果表明:粒化工艺和原料条件相对稳定情况下,氧化球团固结指数越高,球团固结越完全,球团抗压强度越大.该方法不仅可掌握球团矿自身物性,而且能够准确表征球团氧化焙烧的固结程度,为科研、生产人员提供了一种氧化球团矿质量的评价指标.     

S2O82-/ZrO2-SiO2固体酸制备及性能的研究

采用沉淀-浸渍法,通过改变硅锆摩尔比、焙烧温度及焙烧时间3个变量,制备了一系列S2O82-/ZrO2-SiO2固体超强酸催化剂。通过单因素实验,考察了硅锆摩尔比、焙烧温度及焙烧时间对蔗糖制备乙酰丙酸的影响。实验结果显示:随着硅锆比从3增加到5,乙酰丙酸的收率持续降低;随着焙烧温度从500℃升高到600℃,乙酰丙酸的收率开始时先降低,到550℃以后则升高;随着焙烧时间从2h增加到4h,乙酰丙酸的收率开始时先升高,到3h以后则降低。当焙烧温度500℃、焙烧时间4h、硅锆比1∶4时,制备的催化剂的比表面积最大,催化活性最高;将该条件下制备的催化剂用于蔗糖的水解反应,乙酰丙酸的收率为17.4%。     

响应曲面法优化钒渣微波钙化焙烧提钒工艺

采用相应曲面法,建立钙化添加剂用量、焙烧温度、焙烧时间与钒浸出率关系的数学模型,对钒渣微波钙化焙烧提钒工艺进行优化,并对试验结果的可靠性进行分析与验证。研究结果表明,采用响应曲面法优化钒渣微波钙化焙烧提钒工艺参数是可行的;微波钙化焙烧工艺参数对钒浸出率的影响从大到小依次为钙化添加剂用量、焙烧温度、焙烧时间;最佳焙烧参数为焙烧温度861.69℃、钙化添加剂用量1.02、焙烧时间106.31 min,此时钒的浸出率可达93.82%。     

高砷河道尾砂还原焙烧脱砷研究

【目的】对河道尾砂富集分离形成的高砷尾砂进行脱砷处理,使之达到高炉冶炼的要求。【方法】在前期氧化焙烧脱砷研究的基础上,分别采用煤基还原焙烧工艺和气基还原焙烧工艺对含砷量为0.47%的河道尾砂氧化焙烧渣进行脱砷试验。考察焙烧温度、时间、还原气氛CO/(CO+CO_2)和空气流速等主要影响因子对脱砷效果的影响。【结果】气基还原焙烧的脱砷效果优于煤基还原焙烧。气基还原焙烧的适宜条件:焙烧温度900℃、焙烧时间约30min、CO/(CO+CO_2)浓度20%、气体流量0.5m3/h;在适宜的气基还原焙烧条件下,焙烧尾砂中砷的含量可降至0.058%,脱砷率达87.66%。【结论】经气基还原焙烧工艺得到的河道尾砂还原焙烧渣能满足高炉炼铁的要求。     

硫酸化焙烧氧化锰矿浸出锰的循环工艺

为降低氧化锰矿处理成本,有效利用电解金属锰产生的废酸,采用硫酸铵循环利用工艺,进行氧化锰矿硫酸化焙烧—浸出试验。研究结果表明:硫酸钠对氧化锰矿硫酸化焙烧及硫酸铵分解有较好的促进作用。当焙烧温度为500℃时,锰浸出率较高,而三氧化二铁很难转化为可溶性硫酸亚铁,浸出液中铁杂质含量低,锰选择性浸出效果较好。在适宜的焙烧和浸出工艺条件下,通过硫酸化焙烧和浸出,锰浸出率可达89.93%,NH_4~+回收率可达98.62%,SO_4~(2-)回收率可到88.22%。     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-