棕榈油乙酯化合成脂肪酸乙酯及其动力学

为了研究反应条件对乙酯化反应的影响，提高脂肪酸乙酯的转化率，本文以氢氧化钠催化棕榈油与无水乙醇发生酯化反应合成棕榈油脂肪酸乙酯。首先考察棕榈油的理化性质，然后通过单因素实验和正交实验考察反应过程中醇油物质的量比、催化剂用量、反应温度、反应时间对乙酯化反应合成棕榈油脂肪酸乙酯转化率的影响，并用FT-IR和TLC对棕榈油脂肪酸乙酯进行表征和分析。结果表明：优化的工艺条件为醇油物质的量比为7∶1,催化剂质量分数为0.8%(占棕榈油质量),反应温度为75℃,反应时间为2.0 h时，棕榈油脂肪酸乙酯的转化率为95.6%,且高于同类产品。动力学研究表明：酯化过程为二级反应，在反应温度为60、70、80℃的反应速率常数分别为0.059 8、0.102 1、0.166 3 L/(mol·min),活化能为2.033 0 kJ/mol。     

菜籽油制备生物柴油的研究

研究了菜籽油在KOH催化剂作用下与甲醇进行酯交换反应制备生物柴油的过程,着重考察了醇油比、催化剂用量和反应温度等操作条件对反应的影响,试验结果表明,该反应最适宜的操作条件为醇油的物质的量之比为61,催化剂用量为菜籽油质量的1%,反应温度为65～70℃,反应时间为90～120min.     

固体碱MgO/ZrO2催化大豆油制备生物柴油

采用共沉淀法制备固体碱催化剂MgO/ZrO2,并以此催化大豆油与甲醇酯交换反应制备生物柴油。考察MgO含量和催化剂焙烧温度对催化剂活性的影响,以及优化酯交换反应的工艺条件,结果表明:在MgO质量分数为15%、焙烧温度700℃、反应时间3 h、反应温度60℃,醇油物质的量比12∶1和催化剂用量为大豆油质量的3%的条件下,生物柴油的产率可以达到82%以上。该催化剂对酯交换反应具有较高的催化活性和较好的稳定性。     

利用大豆酸化油合成生物柴油的工艺研究

采用大豆酸化油在催化剂浓硫酸的作用下与甲醇发生酯化反应制备脂肪酸甲酯（生物柴油）,研究了醇油摩尔比,催化剂质量分数,反应时间,反应温度等对产物收率的影响。通过正交试验得到最佳反应条件：醇油摩尔比16：1,催化剂质量分数2％,反应时间8h,反应温度70℃。在最佳条件下,酸化油酸值由128降至5．6,酯化率达到95．6％,生物柴油的收率为68．0％。     

基于均匀设计的生物柴油最优制备工艺参数研究

以均匀设计法安排试验,对大豆油在酯交换反应下制备生物柴油的工艺进行了研究.为获得最优制备工艺参数,考查了n(醇)∶n(油)(3∶1～8∶1)、催化剂质量分数(0.4%～1.4%)、反应温度为(45～70℃)、反应时间(40～140min)及其交互作用对生物柴油产率和原料转化率的影响.结果表明:n(醇)∶n(油)、催化剂用量可显著地影响生物柴油的产率和原料转化率.同时甲醇与反应温度、催化剂与反应时间之间存在对抗效应,而甲醇与反应时间、催化剂与反应温度、反应温度与反应时间之间则存在协同作用.利用回归分析和BP神经网络,确定最优工艺参数为:n(醇)∶n(油)=6∶1;催化剂质量分数1.0%;反应温度45℃;反应时间30min.经液相色谱仪测定,生物柴油产率高达97.6%.     

大豆油酯交换法制备生物柴油

采用大豆油在催化剂氢氧化钠作用下与甲醇发生酯交换反应制备生物柴油.研究了醇油摩尔比、催化荆质量分数、反应时间、反应温度等对反应产率的影响.采用红外光谱表征产品.实验结果表明,当醇油摩尔比5.9:1,反应时间2 h,催化荆用量为原料油质量的0.99%,反应温度65℃时,生物柴油的收率最高,为87%.     

活性炭负载磷钨酸催化合成丁醛乙二醇缩醛

用活性炭负载磷钨酸催化合成丁醛乙二醇缩醛,研究了催化剂的用量,反应温度,反应时间,醛醇物质的量之比及带水剂等因素对反应的影响.实验表明:丁醛和乙二醇的物质的量比为1∶1.5,催化剂用量为反应物料总质量分数的1.0%,环己烷为带水剂,反应时间40 min的优化条件下,丁醛乙二醇缩醛的产率可达93.53%.并且催化剂可重复使用.     

柠檬酸三丁酯的合成研究

以柠檬酸和正丁醇为原料,对甲苯磺酸为催化剂合成无毒增塑剂柠檬酸三丁酯(TBC).探讨了酸醇物质的量比、催化剂用量、反应时间、反应温度、带水剂等对反应的影响,并对催化剂进行了重复利用研究,产品经气相色谱和红外光谱分析.确定的最佳工艺条件为:酸醇物质的量比为1∶4,催化剂用量为柠檬酸质量的3%,反应时间4 h,产率达96.3%.     

磷钨酸/活性炭催化合成二甘醇双丙烯酸酯

用磷钨酸／活性炭为催化剂，催化合成二甘醇双丙烯酸酯，其性能优于硫酸和其他质子酸。结果表明，在酸醇物质的量比为2．1：1、催化剂用量为丙烯酸质量的1．3％、反应温度为115－120℃、反应时间75min及以甲苯为共沸剂的条件下，酯化率达94．2％，产品质量分数大于98％，并且催化剂可以重复使用多次。     

单十二烷基磷酸酯合成工艺研究

以多聚磷酸和五氧化二磷相结合作为磷酸化试剂和十二醇反应合成单十二烷基磷酸酯,考察了反应时间、反应温度、原料物质的量比、反应物浓度等因素对反应的影响.在磷酸化试剂和十二醇反应温度为80℃,反应时间为5 h,多聚磷酸和五氧化二磷加入的摩尔比1∶1,多聚磷酸的质量分数110%(以磷酸计)等工艺条件下,单烷基磷酸酯质量分数为78.77%,双烷基磷酸酯质量分数为14.02%,磷酸质量分数为3.34%,十二醇的转化率为98.67%.     

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。     

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.     

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.