一种烷基转移反应体系的反应条件和热力学分析

对甲苯歧化与三甲苯烷基转移反应体系中不同温度和进料条件下的平衡组成，平衡转化率，平均选择论进行了详细计算，结果表明：（1）随温度的升高，甲苯与三甲苯的芳烃平衡转化率降低，二甲苯的平衡选择率亦降低；（2）降低进料中的甲苯与三甲苯摩尔比（Tol:TMB从9降到1），甲苯和三甲苯的芳烃平衡转化率降低，而二甲苯的平衡选择率明显上升，然后，在改性的β沸石催化剂上进行了不同工艺条件下的反应，通过对实验数据与平衡数据的比较和分析表明，反应温度升高，芳烃转化率上升且越来越接近平衡转化率，而二甲苯的选择率迅速下降；进料 中Tol:TMB存在一个最佳点，即60:40(m：m），此时芳烃转化率最高，二甲苯的选择率亦最高。     

乙苯脱氢径向反应器的模拟和操作优化

采用一维拟均相绝热径向反应器模型模拟乙苯负压脱氢径向反应器,探讨了在负压条件下乙苯脱氢反应温度、水烃比和压力对乙苯脱氢反应转化率和选择性的影响,指出负压反应系统对压降的严格要求,由此得出合理的操作条件,通过模型计算结果与生产装置实测数据的比较,确认本模型可以用于生产装置的模拟。     

直序双塔精馏分离BTX过程的稳态模拟与动态控制研究

利用Aspen Plus模拟软件对BTX直接序列双塔精馏过程进行稳态研究,在设计规定下分别对苯塔和甲苯塔的操作参数进行确定和优化,确定了各塔的理论塔板数、最佳进料位置、回流比以及灵敏板温度.在稳态模拟设计数据的基础上,采用Aspen Dynamics考察了进料流量扰动(±10%)和进料组成扰动(±10%)的工况下,各项控制指标均可在较短响应时间内达到平衡,动态控制结构可以很好地应对工艺过程中进料流量和进料组分的扰动.     

聚丙烯反应器稳定性分析

建立了针对本体法连续搅拌槽式聚丙烯反应器 (CSTR)的动态机理模型 ,并在定态点处进行线性化处理 ,以建立线性化模型 ,从工艺和控制角度对聚丙烯反应器的稳定性进行了全面分析。结果表明 ,丙烯聚合这种非线性、强放热、开环不稳定的CSTR与理想的CSTR有着很大的不同 ,放热速率不仅是温度的函数 ,而且受丙烯浓度、催化剂浓度的影响也很大。反应过程中转化率很低 ,再加上丙烯的临界温度也很低 ,温度升高会使冷凝潜热减少 ,单靠夹套冷却水难以移走反应热 ,从而造成高温稳态点 (开环稳定点 )的不存在。在假稳态的操作点处 (开环不稳定点 ) ,系统受到扰动而使温度升高 ,如不加任何控制将导致反应器烧毁。如果进料温度、催化剂初始浓度等发生变化也将导致假稳态点的变化 ,这时如果仍然按着原来的操作点进行操作 ,势必造成反应温度波动 ,影响产品质量     

聚丙烯反应器稳定性分析

建立了针对本体法连续搅拌槽式聚丙烯反应器(CSTR)的动态机理模型，并在定态点处进行线性化处理，以建立线性化模型，从工艺和控制角度对聚丙烯反应器的稳定性进行了全面分析。结果表明，丙烯聚合这种非线性、强放热、开环不稳定的CSTR与理想的CSTR有着很大的不同，放热速率不仅是温度的函数，而且受丙烯浓度、催化剂浓度的影响也很大。反应过程中转化率很低，再加上丙烯的临界温度也很低，温度升高会使冷凝潜热减少，单靠夹套冷却水难以移走反应热，从而造成高温稳态点(开环稳定点)的不存在。在假稳态的操作点处(开环不稳定点)，系统受到扰动而使温度升高，如不加任何控制将导致反应器烧毁。如果进料温度、催化剂初始浓度等发生变化也将导致假稳态点的变化，这时如果仍然按着原来的操作点进行操作，势必造成反应温度波动，影响产品质量。     

邻二甲苯氧化生产苯酐过程的模拟与优化

建立了邻二甲苯氧化生产苯酐过程的二维拟均相动力学模型,利用gPROMS进行模型求解,结果与实验数据吻合较好。通过热点温度控制范围确定了反应器进料温度、换热介质熔盐温度的控制范围。以邻二甲苯转化率最大为目标函数,以反应器进料温度、熔盐温度为控制变量,利用gPROMS优化反应过程,得到优化条件下的邻二甲苯转化率可达98.4％。     

一种用于二维稳态固定床的通用计算方法

针对固定床反应器模拟过程难以形成其模型完整通用的计算模块且编程工作量大的问题,提出了一种稳态下固定床反应器中反应物和产物温度及浓度分布的通用计算方法.该方法以关键组分的摩尔分数作为变量,推导出关键组分在物料与热量衡算中的偏微分方程组中的通式,并利用正交配置法求解.同时考虑固定床反应器内气相流速的变化,将其描述为关键组分摩尔分数的函数进一步实现模型的通用性.对于特定的反应,只需提供目标反应的动力学方程及操作条件即可求解.最后利用所提出的方法实现乙苯催化脱氢制苯乙烯与乙炔法制氯乙烯反应过程的模拟,结果表明该方法具有通用性和高效性.     

催化裂化装置的动态模拟与操作分析

催化裂化装置的动态模拟和操作分析是优化操作和先进控制的基础。在强调催化裂化动态机理模型的优点后,对二级裂化反应转化率经验模型和集总反应动力学模型两大类动力学模型、再生过程中烧碳、烧氢动力学模型、床层再生器流化模型、快速床再生器流化模型和反应器 再生器动态数学模型进行了详细的评述,并指出运用动态机理模型对装置操作进行分析,特别是装置稳定性分析可以为催化裂化装置的设计、操作和控制提供依据     

催化裂化装置的动态模拟与操作分析

催化裂化装置的动态模拟和操作分析是优化操作和先进控制的基础.在强调催化裂化动态机理模型的优点后,对二级裂化反应转化率经验模型和集总反应动力学模型两大类动力学模型、再生过程中烧碳、烧氢动力学模型、床层再生器流化模型、快速床再生器流化模型和反应器再生器动态数学模型进行了详细的评述,并指出运用动态机理模型对装置操作进行分析,特别是装置稳定性分析可以为催化裂化装置的设计、操作和控制提供依据.     

乙苯脱氢制苯乙烯工业生产过程的模拟与优化

利用建立的乙苯脱氢反应动力学模型 ,对乙苯脱氢制苯乙烯反应过程进行了计算机模拟 ,借助流程模拟软件ASPENPLUS 10.1,在灵敏度分析的基础上确定了苯乙烯生产过程的最佳操作条件。     

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.     

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.     

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.     

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.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.