二甲苯异构化反应特性与HZSM-5沸石催化剂性能的关系研究

采用脉冲微反和HN3中毒法，研究了在HZSM-5沸石催化剂上二甲苯异构化反应特性，催化剂表面酸性与邻二甲苯异构化的活性和选择性的关系，确定了在200-350℃范围内的中等强度的酸中心是参与二甲苯异构化的活性中心，这些酸中心数增加，其反应的活性和选择性增加，阐述了HZSM-5的结构因素对其选择性的影响。     

金属元素改性后的液化石油气制芳烃催化剂性能评价

利用X射线衍射和红外光谱分别表征了金属元素改性的HZSM-5分子筛液化石油气芳构化催化剂,并且在反应温度510 ℃、进料空速0.25 h-1和系统压力0.1MPa的条件下,利用100 mL固定床实验装置考察了改性金属元素种类、改性金属元素含量和双金属元素改性对催化剂性能的影响.结果表明,HZSM-5分子筛经锌或锌-铝改性后物相基本没有变化,但是改性后催化剂B酸中心减少,L酸中心明显增加,并出现新的芳构化活性中心.在Zn/HZSM-5催化剂上,液化气芳构化的芳烃收率比HZSM-5催化剂提高22%,并且催化剂的稳定性明显改善;Zn-Al/HZSM-5芳构化催化剂不仅能进一步提高液化气芳构化的芳烃收率,还能有效延长催化剂的使用寿命;当Zn-Al/HZSM-5催化剂上锌含量为2.0%～4.0 %,铝含量为2.0%～3.0%时,催化剂表现出最好的活性及稳定性.     

金属元素改性后的液化石油气制芳烃催化剂性能评价

利用X射线衍射和红外光谱分别表征了金属元素改性的HZSM-5分子筛液化石油气芳构化催化剂,并且在反应温度510 ℃、进料空速0.25 h-1和系统压力0.1MPa的条件下,利用100 mL固定床实验装置考察了改性金属元素种类、改性金属元素含量和双金属元素改性对催化剂性能的影响.结果表明,HZSM-5分子筛经锌或锌-铝改性后物相基本没有变化,但是改性后催化剂B酸中心减少,L酸中心明显增加,并出现新的芳构化活性中心.在Zn/HZSM-5催化剂上,液化气芳构化的芳烃收率比HZSM-5催化剂提高22%,并且催化剂的稳定性明显改善;Zn-Al/HZSM-5芳构化催化剂不仅能进一步提高液化气芳构化的芳烃收率,还能有效延长催化剂的使用寿命;当Zn-Al/HZSM-5催化剂上锌含量为2.0%～4.0 %,铝含量为2.0%～3.0%时,催化剂表现出最好的活性及稳定性.     

HZSM-5/堇青石整体式催化剂的制备及催化性能

以整体式堇青石蜂窝陶瓷为载体,经预处理后涂覆HZSM-5分子筛,制备出含不同HZSM-5质量分数的HZSM-5/堇青石整体式催化剂。采用XRD和BET对催化剂的结构进行了表征,在常压微型固定床反应装置上评价催化剂的甲醇制烯烃反应性能,并考察了催化剂中HZSM-5分子筛的质量分数、反应温度、气体空速等与烯烃组成分布的关系。结果表明：HZSM-5/堇青石整体式催化剂中仍保持HZSM-5分子筛的XRD特征衍射峰;催化剂的比表面积、孔体积随着HZSM-5质量分数的增加而增加;催化剂中HZSM-5分子筛质量分数为22.5%时具有最好的活性,在反应温度为380℃、气体空速为820mL/(g·h)的条件下,乙烯的选择性为35.22%,丙烯的选择性为30.95%。     

用HZSM-5催化剂直接合成对甲乙苯的研究

本文用适当处理的HZSM-5催化剂进行甲苯乙烯烃化直接合成对甲乙苯,该催化剂经 过 200小时的长运转试验表明具有良好反应性能。还探讨了 HZSM-5沸石催化剂的表面酸 性质及微孔有效扩散系数与其择形催化的关系。 1.实验部分 1.1 催化剂制备 由本实验室用氨水合成的 ZSM-5与粘结剂 Al2O3混合成型,经硝酸铵溶液交换,制得 HZSM-5催化剂,再经适当处理制得五种不同性能的 HZSM-5催化 剂。 1.2 烷基化反应 该反应是在常压小型固定床积分反应器中进行,以甲苯转化率CT(mol%)表示催化剂活性;以产物中对甲乙苯与甲乙苯总和之比Sp(%)表示对位选…     

负载型Nb2O5对异丁烯与异丁醛缩合反应催化性能

使用Hammett指示剂、吡啶吸附红外光谱(Py-IR)和微反测试等方法考察了负载型Nb2O5-TiO2/γ-Al2O3表面酸性特征和对异丁烯(IB)与异丁醛(IBA)缩合生成2,5-二甲基-2,4-己二烯(DMHD)反应的催化活性.结果表明,催化剂活性与其表面酸特征有关,催化剂表面B酸中心可能是IB与IBA缩合生成DMHD的反应活性中心,但较强的B酸中心导致产物DMHD选择性降低,L酸中心对该反应几乎不起催化作用.将TiO2引入γ-Al2O3表面后,增加了Nb2O5/γ-Al2O3催化剂表面B酸中心酸量,从而提高了催化剂的活性.     

HPW改性HZSM-5催化乙醇流化床脱水制乙烯

采用HPW浸渍改性HZSM-5分子筛,将其应用于催化乙醇流化床脱水制乙烯反应,探讨工艺条件对催化性能的影响.实验结果表明:HPW浸渍浓度为0.04mol/L,浸渍时间为24h,焙烧温度为350℃,焙烧时间为4h时所得催化剂催化乙醇脱水制乙烯性能最佳,此时乙醇转化率和乙烯选择性可以分别达到98.1%和97.1%.采用XRD、NH3-TPD、XPS等手段对催化剂结构进行表征,结果表明HPW的"假液相"行为和适量的二级结构能够协同催化反应,催化剂的酸中心强度和酸量大小决定了催化剂的活性.     

SO_4~(2-)改性锆交联蒙脱土的表面酸中心及催化活性

研制SO42-改性的锆交联蒙脱土(SO42-/Zr-CLM)固体酸催化剂,采用IR、Py-TPD和Py-IR等方法研究其表面酸中心的结构特征,并以柠檬酸和正丁醇的酯化反应为探针反应,研究其表面酸中心与催化活性的关系.实验结果表明:SO42-/Zr-CLM表面同时具有Bronsted(B)酸和Lewis(L)酸,L酸为弱酸中心,B酸为强酸中心;B酸中心是主要催化活性中心;催化剂经过500℃焙烧后,B酸的酸量显著增加,这可能是由于Zr与SO42-形成了螯合状配位结构,有利于形成更多的B酸中心并且提高其酸强度.     

裂解汽油在ZSM-5沸石上的芳构化

采用连续流动反应装置,考察了裂解汽油在HZSM-5与金属元素改性的HZSM-5上的芳构化反应,发现锌改性后提高了液体产物中芳烃的收率。为了克服裂解汽油中含硫含焦杂质的影响,提出了获取芳烃的有效工艺:蒸馏除焦-加氢预脱硫-氢气氛下芳构化反应-冷凝产物。用氨吸附的程序升温脱附法,将催化剂的酸性质与其催化芳构化作用进行关联,认为Zn改性后的HZSM-5催化剂具有较温和的酸中心,可能是其芳构化高活性与高选择性的原因。     

MgO修饰的HZSM-5分子筛对甲苯甲醇烷基化反应性能的影响

采用浸渍法制备了系列MgO修饰的HZSM-5分子筛催化剂，通过X射线衍射(XRD)、扫描电子显微镜(SEM)、NH₃程序升温脱附(NH₃-TPD)、吡啶红外(Py-IR)等方法对修饰前后的HZSM-5分子筛催化剂进行表征，并在固定床反应器上对催化剂的性能进行评价.结果表明：MgO的修饰并未对HZSM-5分子筛的晶体结构有明显影响，但是部分MgO优先覆盖了分子筛表面的强酸位，从而降低了分子筛的酸强度，并改变了B酸/L酸比例；同时由于MgO堵塞部分孔道造成分子筛比表面积降低，进一步降低了分子筛表面酸性位的数量，影响甲苯甲醇烷基化反应性能和产物分布.MgO修饰后的HZSM-5分子筛，虽然使甲苯转化率降低，抑制了甲苯歧化反应、深度烷基化反应和缩聚反应的发生，但是有利于对二甲苯和乙基甲苯的生成，表现出一定的择形催化性能.     

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.     

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.     

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.     

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.     

A computer generator for randomly layered structures

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

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.