氨磺酸催化合成异丁酸丁酯

以氨磺酸为催化剂催化合成了异丁酸丁酯，确定了酯化优化条件，实验结果表明，醇酸摩尔比为1．8，异丁酸用量为0．2mol的情况下，催化剂用量1．0g，带水剂甲苯15mL,反应时间2．0h，反应温度107－116℃是最佳反应条件，酸的酯化率达到97．5％。     

四氯化锡催化合成柠檬酸三丁酯的研究

本文研究了以四氯化锡水合物作催化剂催化合成柠檬酸三丁酯，确定了酯化优化条件。实验结果表明，醇酸摩尔比为4：1，柠檬酸用量为0．2mol的情况下，催化剂用量为反应物质量的2．5％，带水剂甲苯15ml，反应时间80min，反应温度为108－148℃是最佳反应条件，酸的酯化率达到96．23％。     

S2O8^2-／TiO2-SiO2催化合成柠檬酸三丁酯

以固体超强酸S2O8^2-／TiO2-SiO2为催化剂合成柠檬酸三丁酯，考察了醇酸摩尔比、催化剂用量、反应时间、反应温度及催化剂重复使用对酯化反应的影响。结果表明酯化反应的最佳条件为：酸醇摩尔比为1：5．4，催化剂用量为反应物总质量的0．94％，反应时间为6小时，反应温度为130℃，此条件下酯化率可达93．4％。该催化剂具有制备简便，与产品分离容易，不易腐蚀设备，重复使用后仍保留良好的活性等优点。     

酶催化合成丁酸丁酯

以酶为催化剂，正丁醇与王丁酸一步反应可合成丁酸丁酯，本实验考察了不同类型的酶催化剂和普通催化剂、酶催化剂用量、醇酸摩尔比、反应温度、反应时间等因素对合成酯收率的影响．优化的反应条件：醇酸摩尔比为1．3：1．0，酶催化剂用量比为4．0％，反应时间为30min，反应温度为25—35℃，酯产率可达94．1％．     

新型汽油辛烷值改进剂

目的 合成一种新型汽油辛烷值改进剂——甲氧基异丁酸烷基酯。方法采用烃化反应合成甲氧基异丁酸烷基酯，研究法测定汽油辛烷值。结果甲醇与甲基丙烯酸甲酯的配料比（物质的量比）为1．8：1，反应时间为4h，催化剂用量为15％（质量分数），阻聚剂的量为0．2％（质量分数），此条件下产品收率为87．3％。结论改进剂添加量为3％～7％（体积分数）时，汽油辛烷值可提高1．5～10个单位。     

活性炭负载杂多酸(PW12/C)催化合成1,4-丁二醇双马来酸AEO2双酯

以1，4-丁二醇，马来酸酐，十二醇聚氧乙烯醚(AEO2)为原料，合成了一种结构新型的化合物——1，4-丁二醇双马来酸AEO2双酯，此化合物的合成由两步酯化反应组成，酯化反应Ⅰ采用正交实验，确定最优工艺条件为：n(马来酸酐)：n(1，4-丁二醇)=2．15：1．00，反应时间1h，催化剂用量ω(乙酸钠)=1．0％．酯化反应Ⅱ采用活性炭负载杂多酸(PW12／C)为催化剂，该催化剂的最优制备条件为：m(PW12)：m(C)==4：6，回流时间4h，烘干温度150℃，烘干时间4h．酯化反应Ⅱ采用均匀实验优化工艺条件，最优工艺条件为：n(1，4-丁二醇双马来酸单酯)：n(AEO2)=1．00：2．15，反应温度150℃，反应时间14h，催化剂用量ω(PW12／C)=1．5％，对每步合成的产物结构用IR和1HNMR进行表征。     

强酸性阳离子交换树脂催化合成甘油三乙酸酯的研究

以乙酸、甘油为原料,直接酯化合成甘油三乙酸酯,研究了反应温度、反应时间、原料配比、带水剂、催化剂用量等条件对合成反应的影响,确定了最佳工艺条件。该方法合成甘油三乙酸酯的最佳工艺条件是：反应温度92～98℃;反应时间5h;n(乙酸)：n(甘油)为4．5：1．0;催化剂用量为总物料质量的0．9％;带水剂苯用量为15mL(甘油为0．15mol的情况下)。甘油三乙酸酯的收率达到92．30％。催化剂不经处理可循环使用多次。该催化剂具有价廉易得、催化活性好、不腐蚀设备、无环境污染等优点。     

TSA催化合成二亚苄基山梨醇的研究

研究了利用多种催化剂在不同条件下合成1,3;2,4－二亚苄基山梨醇,结果表明：采用TSA为催化剂,当山梨醇,苯甲醛＝1：2．4（物质的量比）,催化剂,甲醇,环已烷用量分别为反应基础的4．0％,2475,584％,反应温度75℃,反应时间5h,产率可高达95．5％。     

壬基酚聚氧乙烯磷酸盐催化乙氧基化反应

以壬基酚聚氧乙烯醚(NP-4)为原料合成了壬基酚聚氧乙烯醚磷酸酯钾盐，用电位滴定法测定了单双酯的含量，并分别用于催化乙氧基化反应。通过色质连用仪测定了乙氧基化产物的分子量分布。研究结果表明，当n(壬基酚聚氧乙烯醚(NP-4))：n(五氧化二磷)=1：2，在70℃下反应5h，单酯的含量为75％．以其钾盐(cat-1)为催化剂，当n(正辛醇)：n(环氧乙完(EO))=1：4，催化剂用量为0．5％，在150℃下反应5h，正辛醇的转化率可达到90％，同时乙氧基化产物的分子量分布选择性指标是相同条件下NaOH为催化剂的1．7倍。     

TiSiW12O40／TiO2催化合成葡萄糖五丙酸酯

报道了新型催化剂TiSiW12O40／TiO2催化酯化合成葡萄糖五丙酸酯的糖酸比、催化剂用量、反应时间、反应温度诸因素对产率的影响。实验表明：TiSiW12O40／TiO2是合成葡萄糖五丙酸脂的良好催化剂。最佳反应条件为：糖酸摩尔比1：6．催化剂的用量为反应液的2．0％．酯化反应时间为2.0h,反应温度95℃～105℃．反应产率可达84．5％。     

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