纤维素在炭化和活化过程中的结构变化

以纤维素为原料,通过在氮气氛下炭化和水蒸气活化得到纤维素基炭.采用热分析、傅里叶红外光谱、X射线衍射及低温N2吸附测试手段研究了纤维素的炭化和活化过程以及过程中炭微晶结构和比表面积的变化.纤维素分子结构中的C—OH、C—O—C、C—H等基团在280~380℃之间大量分解,380℃后少量裂解产生的小分子碎片或基团持续分解,同时碳元素发生结构重排,形成石墨微晶.炭化温度是影响纤维素基活性炭微晶结构及孔结构的关键因素,随炭化温度的升高,石墨微晶尺寸变大,孔结构得到发育,但活性炭的比表面积则呈先增加后下降趋势,当炭化温度为600℃时所得活性炭比表面积最大;炭化时间对炭微晶结构及比表面积的影响不显著;随着活化时间的延长,先是炭结构中的非微晶碳被氧化,比表面积及总孔容积变大,然后微晶碳被氧化,微晶结构被破坏,炭中部分微孔变成中孔或大孔,导致比表面积及总孔容积变小,当微晶间的非微晶碳被充分氧化而又不破坏原微晶结构时得到的炭孔隙最丰富.     

皮革废料焦的结构与CO_2气化特性实验研究

利用孔隙率及比表面积分析仪、扫描电镜、热天平和X射线衍射仪分别对真皮皮革废料焦的结构特性、气化特性和碳微晶结构特性进行了表征分析。研究结果表明:皮革废料热解后形成的焦孔隙结构发达,其总孔容积和比表面积分别是锡林浩特褐煤焦的7倍和19.4倍;皮革废料焦的碳微晶结构高度有序化,石墨化度达98.26%;皮革废料焦气化起始温度约为921℃;升温速率对皮革废料焦与CO2气化反应影响明显,随着升温速率的提高,气化反应的平均表观活化能降低;皮革废料焦气化活性低于锡林浩特褐煤焦。虽然皮革焦具有较高的孔隙率和比表面积,但碳微晶结构的高度石墨化导致了皮革废料焦本征反应活性较低。在皮革废料焦中添加锡林浩特褐煤焦可提高混合焦样的气化活性。     

不同热解温度下杨树各组分生物质炭的理化特性分析与评价

【目的】通过对不同热解温度下杨树树叶、树枝、树皮生物质炭和秸秆生物质炭的理化特性及结构进行分析,筛选出更适用于林地土壤改良的农林废弃物种类和热解温度。【方法】以杨树不同组分树叶、树枝、树皮和秸秆等4种农林废弃物为原料,分别在300、500和700 ℃温度下制备生物质炭,测定其产率、pH、全碳、全氮含量、阳离子交换量(CEC)、比表面积和表面官能团等指标。【结果】随着热解温度的升高,4种原料生物质炭的产率逐渐降低,灰分含量和pH升高。同一热解温度下,树枝和树皮生物质炭的全碳含量高于树叶和秸秆生物质炭的,而全氮(TN)、全磷(TP)和全钾(TK)含量均低于树叶和秸秆生物质炭的。4种生物质炭水溶性盐基离子含量和交换性盐基离子含量均随着热解温度的升高而增加,树叶生物质炭的阳离子交换量总体高于其他3种原料的生物炭。树叶和树皮生物质炭的比表面积和总孔容积总体大于树枝和秸秆生物质炭,树皮和树叶生物质炭在700 ℃时比表面积分别高达597.02和121.01 m²/g。4种原料生物质炭的表面官能团种类基本相同,以芳香骨架为主,表面官能团数量均随着热解温度的升高而减少,芳香化程度增强。【结论】在不同热解温度和原料制备的生物质炭中,树叶和秸秆生物质炭的灰分、pH、N、K和盐基离子含量较高,比较适用于改良酸性土壤,增加土壤养分;而杨树树枝和树皮生物质炭含碳量较高,则适用于土壤固碳,提高土壤有机质含量。其中,500 ℃热解的杨树树叶生物质炭综合性能最好,氮、磷、钾养分耗失最少,阳离子交换能力较强,比表面积大,更适用于土壤改良。     

宜宾煤中氮的形态及其变迁规律研究

利用X射线光电子能谱(XPS)，研究了宜宾煤及其煤焦中氮的官能团结构，分析了氮官能团在热解过程中的迁移。所有煤焦在马弗炉上制取，制焦温度分别为700、900、1100℃。研究结果表明，宜宾煤中氮的官能团有4种，即吡啶(N—6)、吡咯(N—5)、质子化吡啶(N—Q)和氮氧化物(N—X)，其中吡咯含量最大，煤中的N—X就是N—O，是煤中吡啶结构氮与氧直接结合的结果。在700℃热解时，由于煤的脱氧脱氢，吡啶酮和N—O均向吡啶转化，N—Q基本不变。当热解温度升高到1100℃时，N—Q完全分解，残留在煤焦中的氮为吡啶结构，当有氧气存在时被氧化成吡啶酮和N—O。     

热解温度对东胜褐煤等温热解的影响

对东胜褐煤进行等温热解试验,分析热解温度对褐煤热解气的组成、产量和热值的影响,并利用FTIR对褐煤及其热解产物半焦的主要分子结构进行分析。结果表明,随着等温热解温度的升高,褐煤热解产物半焦中脂肪烃类结构及含氧官能团减少;热解气中CO和H2的含量逐渐增加,CO2的含量明显降低,CH4和CnHm的含量先增加后减少,热解气的产量和热值明显增加;当热解温度为700℃时可得到较高热值的热解气,此时φ(H2)高达39.5%。     

人粪生物炭的制备及性能分析

以人粪为原料制备生物炭,以得率、碘吸附值和亚甲基蓝吸附值为评价指标,考察制备过程中升温速率、热解温度和热解时间等因素对自制人粪生物碳吸附性能的影响。利用比表面积及孔径分析仪分析人粪生物碳的孔径分布和孔容以及比表面积。利用扫描电镜和XRD对生物碳的表面形貌和晶体结构进行分析。采用正交实验,确定最佳制备工艺条件。研究结果表明:在最优制备工艺条件下(升温速率15℃/min,热解温度600℃,热解时间70 min),人粪生物炭平均得率为49%,碘吸附平均值为682 mg/g,亚甲基蓝吸附平均值为93 mL/g。在最优条件下制得的人粪生物碳比表面积为690.8 m~2/g,总孔容积为0.329 cm~3/g,中孔容积和微孔容积分别为0.235 cm~3/g和0.087 cm~3/g,平均孔径2.832 nm。生物碳表面比较粗糙,呈现凹凸不平、蜂窝状结构,并且表面存在发达的、孔径不一的孔结构,孔的形状多样。自制人粪生物碳中一部分碳原子形成了比较稳定的片层石墨结构,有利于应用中生物炭性质保持相对稳定。     

四种原料热解产生的生物炭对Pb2+和Cd2+的吸附特性研究

以木屑、米糠、稻杆、玉米秸杆为原料, 在300, 400, 500, 600和700℃下, 氮气保护的无氧气氛中热解制成生物炭, 探讨不同类型生物炭对水溶液中重金属Pb²⁺和Cd²⁺的吸附效果。研究发现, 对于4种生物质原料而言, 在700℃下制备的生物炭对水溶液中Pb²⁺和Cd²⁺的吸附效果均优于其他制备温度下获得的生物炭, 其中稻杆生物炭(700℃)吸附容量最高, 对Pb²⁺和Cd²⁺分别为126.58和60.61 mg/g。利用X射线荧光光谱、环境扫描电子显微镜、气体吸附仪等方法, 分析700℃下制取的4种生物炭的矿物相元素组成、表面形貌及其比表面积。采用X射线衍射法分析4种生物炭样品在吸附重金属后的矿物相特性, 分析其重金属吸附机理。结果表明, 4种生物炭对Pb²⁺和Cd²⁺的吸附均满足Langmuir等温吸附模型, 同时XRD分析显示Pb²⁺和Cd²⁺在生物炭表面以碳酸盐、磷酸盐、硅酸盐和亚硫酸盐形式存在。     

热解和灼烧温度对稻壳灰特性的影响

为了探讨稻壳热解气化过程对稻壳灰物化结构及其活性的影响,研究了热解及灼烧对稻壳灰的表面结构以及微晶结构的影响.结果表明:直接灼烧时稻壳中的非晶SiO2在800℃左右开始转化为鳞石英而失去活性,稻壳经历高温热解后在600℃下灼烧制备稻壳灰可以保护SiO2的活性;灼烧温度对灰的孔隙特性有明显影响,灼烧温度高不利于稻壳灰的表面结构的改善;热解温度对稻壳灰孔隙特性影响较小,稻壳焦炭600℃下灼烧可制取比表面积大于60m2/g的稻壳灰.     

水热提质对内蒙褐煤物化结构及水分复吸的影响

为探究水热提质过程中褐煤物化结构的演变规律及其对水分复吸行为的影响,选取内蒙褐煤在170~330℃下进行水热提质,然后进行水分复吸实验,运用化学滴定和氮吸附对煤样物化结构进行表征。结果表明:水热提质使褐煤含氧官能团和孔结构发生很大变化,孔体积和比表面积随提质温度升高呈现先增大后降低的趋势,羧基和酚羟基分别在200℃和230℃后发生显著分解而不断减少;含氧官能团和孔结构的共同作用使提质煤平衡含水量先增大后减少。为降低褐煤复吸水分的能力,在保证提质煤后续良好转化行为的前提下,需选择300℃左右的水热提质温度,尽可能破坏褐煤孔结构和含氧官能团,从而抑制褐煤对水分的复吸行为。     

木质素基生物炭制备及对亚甲基蓝的吸附性能

研究温度对生物炭得率、吸附性能的影响.采用无氧慢速热解的方法,以酶解木质素为原料,制备不同温度下的生物质炭,测定热解得率、生物炭得率、挥发分、灰分及对亚甲基蓝的吸附值.热解试验结果表明:随着炭化温度从300℃逐渐升高到700℃,热解得率先降低后升高,挥发成分先升高后降低,生物炭得率先降低后升高.在500℃时,热解得率和生物炭得率分别为54.09%和50.77%,灰分含量为3.32%,挥发分含量为45.91%;热解温度为300℃时,木质素基生物炭对亚甲基蓝的吸附值最大,为37.31 mg/g;热解过程中,C—H、C=O键断裂.     

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-