二氧化锰基吸波剂的微波成粒规律及反应机理

用微波辐照粉末状二氧化锰以制备颗粒状二氧化锰基吸波剂,探索其升温过程及成粒规律.发现存在决定二氧化锰是否升温成粒的“临界功率点”,当二氧化锰质量为30.0 g时,临界功率点为580 W.在740 W微波功率下,平均粒径主要分布在0.52 mm与0.40 mm,所占质量百分比分别为20.3%与43.9%.随微波功率升高,成粒粒径向增大的方向移动.提出了过程的反应机理,认为过程分为微波诱导、一次反应(少量)、一次反应(大量)、二次反应、成粒等5个步骤,一次反应、二次反应的临界点分别为535℃、1 870℃,且传热过程应尽量在二次反应临界点以内操作.发现中期升温速率高,前期与后期升温速率低,并对引起该现象的原因进行了分析.二氧化锰基吸波剂与煤以1∶3.0的质量比混合后在680 W微波场中气化的稳定温度达1 504℃,质量损耗率为1.11%,而相同条件下的颗粒活性炭的质量损耗率达43.78%.     

一种流化床CO气化炉的气化工艺方法及其装置

目前我校研发的“一种流化床CO气化炉的气化工艺方法及其装置”被授予发明专利，本发明涉及煤化工领域的煤气化工艺，为一种用O2＋CO2或空气＋CO2为气化剂的流化床CO气化炉的气化工艺方法．其以O2和CO2为气化剂，以焦粉、无烟煤为原料，采用连续气化工作的流化床气化炉为气化设备（即连续气化法）或以空气和CO2为气化剂，0～10mm的焦粉、无烟煤、贫煤、长焰煤、褐煤中一种或几种为原料，     

外场改性对高炉喷吹煤粉燃烧性能的影响

为了提高高炉喷吹煤粉的燃烧率,研究了微波改性对煤粉燃烧率的影响。研究表明,低功率下微波的改性过程对煤粉组成影响较小,同时煤粉中的各物相在改性过程中较为稳定。无烟煤样品的燃烧率在改性后有所提高,当改性功率为264 W,改性时间为30 s时,改性煤粉的活化能相对原煤降低了8.35%,改性煤粉的燃烧率最高提高了8.99%。     

微波与传统加热法制备新疆煤基活性炭的比较研究

随着国内外活性炭需求量的增大,探索出高效制备活性炭的工艺非常重要。本研究以新疆无烟煤为原料,KOH为活化剂,利用微波加热和传统加热法制备煤基活性炭(CAC),研究煤碱比、活化时间、活化温度、微波功率对CAC吸附性能和产率的影响,获得制备CAC的最佳工艺条件为:微波加热法∶煤碱比1∶2,微波时间8 min,微波功率700 W;传统加热法∶煤碱比1∶1,活化时间5 h,活化温度800℃。利用扫描电镜、氮气等温吸附脱附、零点电荷(p Hpzc)、Boehm滴定法对CAC进行表征,结果表明:微波加热法制备的CAC吸附性能优于传统加热法制备的样品,其具有更高的比表面积为1061.93 m2/g,更高的p Hpzc(8.0)及更少的酸性官能团含量(0.986 mmol/g)。上述结果表明微波加热法节能、省时、成本降低,将在材料制备过程中具有显著地应用前景及推广价值。     

微波辐射紫茉莉种子壳制备活性碳的研究

在微波辐射下,以紫茉莉种子壳为原料,磷酸为活化剂制得了粉状活性炭。采用单因素实验法研究了壳粉、磷酸和水的质量比、微波功率、辐射时间等对活性炭性能的影响。确定了微波辐射紫茉莉种子壳制活性炭的最佳工艺条件,测定了活性炭的比表面积。研究结果表明:当m壳粉∶m磷酸∶m水=1∶3∶1.5,微波功率为800 W,辐射时间为15 min时,产品活性炭的比表面积达1583 m2/g、收率为38.8%。     

加氢热解煤焦的二氧化碳和水蒸气气化特性

采用热重分析仪研究了云南玉溪煤和新疆准东煤的加氢热解煤焦二氧化碳气化反应性,考察了成焦压力、停留时间及气氛对煤焦气化反应性的影响,并利用均相模型计算了各煤焦的非等温气化动力学参数。采用实验室固定床反应器,研究了上述两种煤加氢热解煤焦的水蒸气气化特性,考察了成焦气氛对煤焦气化速率和气体产物组成的影响。热重气化实验表明,准东煤焦的气化反应性明显好于玉溪煤焦,前者的反应活化能远小于后者的反应活化能;无论哪种煤,加氢热解煤焦的气化反应性随加氢过程碳转化率的增大呈下降趋势;在相近的碳转化率下,加氢热解煤焦的气化反应性明显好于氮气气氛热解所得煤焦。在水蒸气气化的情况下,准东煤焦的气化反应性同样好于玉溪煤焦。总体上准东加氢热解煤焦的产氢率相比氮气气氛热解所得煤焦有所增加,不过对于这两种煤焦,随着气化温度提高,H2与CO的物质的量之比均逐渐接近于热力学平衡所得的计算值。     

加压下煤焦与二氧化碳反应的动力学研究

本文用试制成的加压热天平,测定了八种中国煤在900℃时制成的煤焦在1.2-31 at.和800-1050℃与CO_2反应的活性。结果表明活性同煤品位有很好的相关性,年轻煤的活性大于年老煤。研究了活性随热处理温度(800—1100℃)的变化。在同一气化温度,活性有规则地随制备温度的降低而增加,在同一热处理温度时,活性随气化温度的增加而增加。计算了表观活化能和制备活化能。由1.2—31 at.850—900℃一种褐煤焦在CO—CO_2混合物中气化得到的结果,关联成下列模型: W=K_1Pco_2/1 K_2Pco K_3Pco_2也讨论了比气化速率和炭转化率的关系。     

蒙古国煤水蒸气气化制合成气及其热力学特性

对来自蒙古国不同地区的4种煤样的水蒸气气化性能进行系统研究,考察了4种煤样水蒸气气化合成气的组成与生成规律;讨论了热力学平衡对4种煤样气化反应的影响。研究发现,巴嘎诺尔煤(BN)、纳赖呼煤(NL)和阿拉格陶盖煤(AT)的水蒸气气化反应性能明显高于塔本陶勒盖煤(TT)。BN、NL和AT煤可通过水蒸气气化反应制高H2含量、低CO含量的合成气,而TT煤水蒸气气化合成气中CO的含量相对较高。造成这种现象的原因是BN、NL和AT煤气化过程中水煤气变化反应(WGSR)进行的较为彻底,消耗了煤与水蒸气直接气化反应所生成的CO,生成更多的H2,而TT煤WGSR进行程度较低,故其合成气中CO含量较高,因此认为热力学平衡是造成不同种类蒙古国煤水蒸气气化特性存在差异的重要因素。     

一种新的水煤气沸腾煤气化炉诞生

我院最近研制成功一种水煤气沸腾煤气化炉,整个气化进程只有供风、气化两个过程,采用自热间歇循环水煤气气化方法。至今国内外尚未见有这种气化炉的报导。 该炉结构简单,操作方便,便于实现自动化作业;可同时供应中热值的水煤气和低压水蒸气;对燃料原煤的要求不高,不仅可使用0～6mm的焦碳、无烟煤,还可使用弱粘结性的烟煤、褐煤等劣质粉煤,因此,煤源丰富,成本低廉。且设置了沸腾余热锅炉,不仅使吹风气的化学热和物理热可以回收,而且气化炉排出的高碳量的灰渣还可进入沸腾余热锅炉再燃烧。这种飞灰的再循环,将大大提高碳的利用率和系统总能量的利用率,并大幅度地减少对环境的污染。     

补白$微波加热煤储层的共轭传热模型

为研究微波和常规加热时煤储层内温度场的演化规律及储层瓦斯解吸量的变化规律,采用理论分析和数值模拟的试验方法,构建了以岩石SEM图像为几何特征,瓦斯和煤基质块体为传热介质的共轭传热模型,对比了常规加热和微波功率为1W 3W 5W 7W时温度场的演化过程.结果表明:微波加热时热量由煤储层内向外传递,传热速率是常规加热的1.5倍,且传热速率与微波功率呈对数增长关系;温度场的分布在微波电场传播方向上具有明显的阶段性和区域分布不均匀性,在距离微波端口处温度值最大,随距离增加温度值快速降低;在端口附近200 um的范围内温度的极差值是中部区域的14倍;瓦斯的吸附量随功率的增大基本呈线性递减关系.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

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.     

Design and analysis of generic LBS application developing platform

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.     

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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