甲烷部分氧化制合成气反应中热点位置的研究

将热电偶插入La2 O3 Ni/MgAl2 O4 催化剂反应床层 ,通过移动热电偶详细考察了反应炉温、空速、原料气组成和加入水蒸气对甲烷部分氧化制合成气反应床层温升的影响。结果表明 ,反应热点位于催化剂床层入口处 ,而且热点位置不受上述反应因素的影响。但是 ,其温升值随空速的增大而升高 ,随反应炉温的升高而降低。反应中引入水蒸气可以降低反应热点的温度 ,但同时使产物中CO2 含量增大。根据反应热计算了燃烧重整机理和直接转化机理的绝热温升 ,与实验结果的对比表明 ,反应床层的温升主要来自于部分氧化反应的放热 ,即甲烷部分氧化制合成气可能是按直接转化机理进行的。极高空速时低甲烷转化率下合成气的选择性并未发生明显的变化 ,这也进一步证明了上述结论     

滴流床反应器中SO2的脱除

利用装填有活性炭的滴流床反应器可以脱除废气中的ＳＯ２。液体周期性的脉冲能够提高副产物Ｈ２ＳＯ４的浓度和反应速率，降低床层压降。影响反应器性能的主要操作参数是气体空速、床层温度、操作周期、液体喷淋时间占整个周期的分率以及喷淋液中的硫酸浓度。在每一个周期下都有一个最优的喷淋时间，喷淋液体的表观速率对ＳＯ２脱除几乎没有影响，它只是降低了出口液体中的硫酸浓度。在较低的床层温度下，升高温度有利于ＳＯ２的脱除     

担载型镍催化剂上CH_4/CO_2重整反应的研究Ⅰ.CaO-Fe_2O_3双金属氧化物助剂的研究

采用固定床流动反应装置及ＴＰＲ等技术考察了ＣａＯ、Ｆｅ２Ｏ３及ＣａＯ－Ｆｅ２Ｏ３等氧化物助剂对Ｎｉ／Ａｌ２Ｏ３催化剂的ＣＨ４／ＣＯ２重整反应制合成气的催化活性和抗积炭性能的影响,结果表明,含ＣａＯ－Ｆｅ２Ｏ３助剂的催化剂能最有效地抑制积炭,同时考察了反应温度、原料气配比及空速对催化剂性能的影响     

管壳型固定床费托合成反应器的数学模拟

根据集总思想,利用蛋壳型钴基催化剂动力学方程,建立了管壳型固定床费托合成反应器的一维拟均相数学模型。对合成油试验装置进行工况模拟,得到的管壳型固定床反应器催化床层中的温度分布、CO转化率、出口组成、C5+的质量分数和时空产率的模型计算值与试验值吻合良好。讨论了反应器进口温度、操作压力、气体体积空速和沸腾水温度对反应结果的影响,结果表明:提高反应器进口温度、沸腾水温度、操作压力使催化床层温度升高,CO转化率升高,C5+的质量分数降低和C5+的时空收率增大;增大气体体积空速使催化床层温度降低,CO转化率降低,C5+的质量分数升高和C5+的时空收率增大。     

大比表面积γ—Mo2N催化剂合成条件的考察

利用ＭｏＯ３和氮化气（Ｎ２－Ｈ２混合气）的程序升温氮化气固还原反应合成了大比表面积的γ－Ｍｏ２Ｎ催化剂。氮化气空速及其组成、程序升温速率对大比表面积γ－Ｍｏ２Ｎ催化剂的形成２有重要的影响。提高氮化气空速、降低程序升温速率有利于高比表面积γ－Ｍｏ２Ｎ催化剂的生成。合成气中水的存在影响着产物的组成和ＢＥＴ比表面积的大小。ＸＲＤ分析表明,当合成气中含有一定量的水时,产物中有金属Ｍｏ生成。在富氢氮化气氛下     

钯催化用于氢气除氧的实验研究

以活性氧化铝为载体,采用超声波浸渍法制备一系列不同钯含量的催化剂,将此催化剂用于除去氢气中的微量氧气的实验。实验测定含有一定氧气的氢气在钯催化作用下,催化剂钯含量和氢气空速对出口氧气浓度的影响,采用红外线热成像方法对催化床层反应区域进行了检测。实验显示,随空速增大,氧气转化率降低。出口氧含量曲线在空速为9s-1和15s-1两处拐点,且钯含量越高,拐点越明显。这些现象表明,在氢氧催化反应中,内扩散为反应的主要控制步骤,在钯含量高于0.2％,提高钯含量对催化反应影响不明显。采用较低的钯含量、较小颗粒、较大催化剂装填量有利于提高除氧反应效率。     

氢气中氧气的钯催化去除

以活性氧化铝为载体，采用超声波浸渍法制备不同钯含量的催化剂，用于氢气中微量氧气的去除．研究了反应过程中催化剂钯含量和氢气空速对出口氧气含量的影响，采用红外热成像方法对催化床层反应区域进行了检测．研究发现，随空速增大，氧气转化率降低；出口氧含量曲线在空速为10～12s^-1和15～17s^-1两处出现拐点，且钯含量越高，拐点越明显．这些现象表明：在氢氧催化反应中，内扩散为反应的主要控制步骤；当钯含量高于0．20％时，提高钯含量对催化反应影响不明显；采用较低的钯含量、较小的颗粒、较大的催化剂装填量有利于提高除氧反应效率．     

二甘醇催化氨化合成吗啉

浸渍法制备了用于二甘醇氨化合成吗啉的催化剂,在高压微型催化反应装置上考察了载体结构、活性组分含量和反应条件对催化剂性能的影响。结果表明：载体可以采用γ－Ａｌ２Ｏ３或（γ＋θ）－Ａｌ２Ｏ３,载体的孔径分布对催化剂的选择性影响极大,最佳孔径分布为孔径〉１０ｎｍ的孔占８０％左右。在镍基催化剂中加入铜,可显著提高选择性,ＣｕＯ与ＮｉＯ最佳摩尔比为０．２８－０． ３０,还确定了反应温度、空速和进料比的最佳值     

γ-Al2O3催化剂上乙醇脱水制乙烯的实验研究

考察了低浓度乙醇在固定床管式反应器中活性氧化铝上催化脱水生成乙烯的反应行为。研究了反应温度、进料流率、乙醇浓度等因素对反应行为的影响规律。结果表明，在410～440℃范围内催化剂对主反应的选择性随着温度的升高而升高，在达到一定的温度后趋于稳定。乙醇转化率对温度并不敏感，而随空速的增大而降低。催化剂选择性随着进料流率增大而增大，之后稳定在99.5%以上。在进料流率小于1mL/min时乙醇转化率高于85%，乙烯收率均在80%以上。当利用低浓度乙醇作原料时，乙醇转化率随乙醇浓度增大而增大，催化剂选择性维持稳定。最终选定的适宜工艺条件：温度420℃左右，进料流率1.0mL/min左右。     

二甘醇催化氨化合成吗啉——催化剂反应性能的研究

浸渍法制备了用于二甘醇氨化合成吗啉的催化剂,在高压微型催化反应装置上考察了载体结构、活性组分含量和反应条件对催化剂性能的影响。结果表明：载体可以采用γ－Ａｌ２Ｏ３或（γ＋θ）－Ａｌ２Ｏ３,载体的孔径分布对催化剂的选择性影响极大,最佳孔径分布为孔径＞１０ｎｍ的孔占８０％左右;在镍基催化剂中加入铜,可显著提高选择性,ＣｕＯ与ＮｉＯ最佳摩尔比为０．２８～０．３０。还确定了反应温度、空速和进料比的最佳值。     

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.     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the