对甲苯磺酸催化微波合成月桂酸甲酯的工艺优化

采用微波辐射加热方法,以对甲苯磺酸为催化剂合成月桂酸甲酯,考察酯化反应条件对产物收率的影响.实验结果表明,反应物甲醇、月桂酸和催化剂的投料摩尔比为n(甲醇)∶n(月桂酸)∶n(催化剂)为20∶1∶0.25,微波功率195W(30%),回流反应70min,酯化收率可达80%.产物用红外光谱,折光率进行了表征.     

2步酯化法制备棕榈酸甲酯

以棕榈酸和甲醇为原料,浓H2SO4为催化剂,采用2步酯化法制备棕榈酸甲酯.第1步反应的最佳条件为:温度为(65±2)℃,催化剂用量为棕榈酸质量的0.5%,甲醇用量为棕榈酸质量的80%,反应时间60 min,酯化率90.06%;第2步反应的最佳条件为:反应温度为(100±5)℃,甲醇流速为1.0 mL/min,反应时间为60 min,棕榈酸甲酯的酯化率为99.26%.     

2步酯化法合成肉豆蔻酸甲酯的工艺研究

以肉豆蔻酸和甲醇为原料,浓硫酸为催化剂,采用2步酯化法合成肉豆蔻酸甲酯.实验结果表明,其最佳工艺参数为:冷凝回流酯化阶段(第1阶段)甲醇的质量分数为80%,催化剂质量分数为0.5%,反应温度为(65±2)℃,反应时间为90 min,酯化率为90.03%;甲醇连续流加酯化阶段(第2阶段)甲醇流速为1.0 mL/min,反应温度为(100±5)℃,反应时间为30～60 min,最终转化率为98.19%.并采用正交法进行验证,得到的单因素实验工艺参数可靠.本实验具有反应时间短,能耗低,转化率高,工艺简单等优点.     

月桂酸甲酯的合成

本文介绍了用月桂酸、甲醇为原料，经硫酸－硫酸钠催化直接酯化合成月桂酸甲酯。     

月桂酸甘油单酯的合成

本文对以月桂酸和甘油为原料,直接酯化制备月桂酸甘油单酯的合成条件进行了试验研究,确定了最佳条件:甘油/月桂酸(摩尔比)为2.5:1,反应温度180℃,反应时间3hr,磷酸作催化剂。在此条件下,单酯收率高达99.27％。合成酯中,单酯含量达到75.34％,超过了近期化学文献报导的水平70.8％。     

二氧化硅负载磷钨酸催化合成月桂酸乙酯

以二氧化硅负载磷钨酸合成月桂酸乙酯,研究了原料量比、催化剂用量、反应温度和反应时间对产品收率的影响.实验结果表明,二氧化硅负载磷钨杂多酸是合成月桂酸乙酯的良好催化剂,在酸醇摩尔比1∶5,催化剂用量为酸质量的6.0%,反应温度90℃和反应时间4.0h的条件下,月桂酸乙酯的产率达到80%以上.     

月桂酸甲酯磺酸钠乳化剂的制备及其在丙烯酸酯乳液聚合中的应用

以月桂酸为原料、甲醇为酯化剂、氯磺酸为磺化剂,通过酯化、磺化、中和等反应制备了月桂酸甲酯磺酸钠（C12-MES）,计算和测定了亲水亲油平衡值（HLB）、临界胶束浓度（CMC）和三相点（K点）,并将其作为乳化剂应用于丙烯酸酯的乳液聚合,考察了乳化剂用量对单体转化率、乳液稳定性、乳胶粒粒径的影响。结果表明,当月桂酸甲酯与氯磺酸物质的量比为1:1.2,熟化时间60 min,且用质量分数为20%的甲醇再酯化,所得C12-MES产品色泽较浅,活性物含量能达到80%以上,其HLB值、CMC、K点分别为14.7、13.20 mmol/L（28 ℃）和0 ℃以下;以制得的C12-MES为乳化剂合成的丙烯酸酯共聚物乳液稳定,乳胶粒的粒径在100～200 nm之间,粒度分布小于0.015。     

月桂酸乙酯合成新工艺的研究

以硅藻土负载硫酸铁为催化剂,4A分子筛作脱水剂,无水乙醇作带水剂,由月桂酸和乙醇回流分水合成香料月桂酸乙酯。通过正交实验确定最佳反应条件为：酸醇摩尔比为1∶10,催化剂用量15%,回流反应12h,温度为72~80℃,酯转化率达93.8%。催化剂可重复使用2~3次。     

硫酸钛催化月桂酸乙酯的合成研究

以固体硫酸钛为催化剂、月桂酸和无水乙醇为原料,合成香料月桂酸乙酯.考察了酸醇物质的量之比,催化剂的用量,反应温度,反应时间及带水剂等因素对合成反应的影响.实验表明: 月桂酸和无水乙醇的摩尔比为1∶5,催化剂用量为反应物料总质量分数的4.5%,环己烷为带水剂, 控制反应温度为90～100℃,反应时间3.5小时的优化条件下, 月桂酸乙酯的收率可达90.7%.     

新型Lewis酸铁钾矾催化合成月桂酸乙酯

以新型Lewis酸铁钾矾为催化剂,通过月桂酸和乙醇反应来合成月桂酸乙酯,考察了各种因素对酯化率的影响。实验结果表明,铁钾矾是合成月桂酸乙酯的绿色催化剂;最佳反应条件是：酸醇物质的量比为1：2.5,催化剂用量为0.6g／0.05mol月桂酸,带水剂苯15mL,反应时间2.5h,此时酯化率可达95.2％,并且催化剂可以多次重复使用。     

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.