茶叶特征香气组分的渗透汽化富集

研究2种不同支撑体的聚二甲基硅氧烷/聚偏氟乙烯(PDMS/PVDF)膜和PDMS/Al2O3膜对茶叶特征香气成分顺式-3-己烯醇(叶醇)、芳樟醇、反式-2-己烯醛以及苯甲醇回收的分离性能。考察操作条件对4种芳香物单组分和混合组分的渗透汽化性能的影响。结果表明:渗透汽化膜对单组分实验芳香组分具有较好的分离因子,随着组分浓度的增加,芳香物的分离因子下降;随着温度的升高,分离因子呈先上升后下降的趋势。在芳香物质量分数为0.01%、温度为30℃的条件下,叶醇、芳樟醇、反式-2-己烯醛和苯甲醇的分离因子分别为64.5、31.5、29.3和28.9。混合体系中各组分的分离因子较单组分体系下降。PDMS/PVDF复合膜比PDMS/Al2O3复合膜具有更高的芳香组分分离因子和芳香物分通量。     

多元组分相互作用对T型分子筛膜蒸气渗透性能的影响

面向组成复杂的溶剂脱水需求,系统考察了T型分子筛膜对水-甲醇、水-乙醇、水-异丙醇二元体系及水-甲醇-异丙醇、水-乙醇-异丙醇三元体系的蒸气渗透分离性能。结果表明:在373 K下,当原料水质量分数为3%时,水-异丙醇体系中的水通量为1.05 kg/(m2·h),分别为水-甲醇和水-乙醇体系水通量的5倍和3.5倍;在水异丙醇体系中加入甲醇或乙醇后,由于甲醇或乙醇进入分子筛膜孔道内阻碍了水的传输,分子筛膜的水通量和分离因子均出现显著下降。通过孔度渗透的方法探讨不同组分与T型分子筛膜间的相互作用,结果表明:组分分子尺寸越小,其在膜孔内的吸附及毛细管冷凝现象越严重,随组分吸附量的增大,对膜孔的堵塞程度越大。研究显示T型分子筛膜的微结构具有良好的稳定性,不容易受组分的吸附行为的影响。     

荷电镶嵌膜的研究进展

荷电镶嵌膜主要用于无机盐与低分子量有机物的分离。本文简要介绍了荷电镶嵌膜及其制备原理、近二十年来荷电镶嵌膜的研究进展和发展动态。荷电镶嵌膜的制造主要有嵌段共聚、接枝改性、界面聚合、共混等方法。荷电镶嵌膜的研究热点主要集中在提高荷电镶嵌膜的荷电容量、控制膜内正负荷电基团的比例、深化研究荷电镶嵌膜的传递机理、表征技术和工业应用等方面。     

新型聚酰胺复合膜的制备及性能研究--Ⅰ.界面聚合工艺条件的影响

以改性后的聚丙烯腈(PAN)超滤膜为基膜、p,p′-二氨基二苯甲烷(DDM)和均苯三甲酰氯(TMC)为单体,采用界面聚合法制备一种新型聚丙烯腈/聚p,p′-二氨基二苯甲烷酰胺复合膜.探索了单体浓度、界面聚合时间以及后处理时间、温度等工艺条件对膜分离性能的影响.采用环境扫描电镜(ESEM)观察复合膜的表面形态及断面结构.     

苯-乙醇-水混合液的分离提纯

在大学物理化学实验教学中,《苯-乙醇-水三组分体系相图的绘制》实验将产生大量的苯-乙醇-水混合废液,并分层为上层苯液(含有少量水和乙醇),下层乙醇-水溶液(含有大量乙醇和水,以及少量苯).文章根据苯、乙醇在水中的溶解度不同,对上层苯液进行多次水萃取乙醇,最后用无水CaCl2干燥处理得到纯苯(98.9%).对于下层乙醇-水溶液,由于苯与乙醇、水形成三元恒沸物,通过蒸馏除去苯,继续蒸馏得到乙醇-水的二元恒沸物(乙醇95.6%,水4.4%)和纯乙醇(99.7wt%).将乙醇-水的二元恒沸物通过CaCl2脱水处理,得到99.4wt%以上的乙醇.     

凝胶剂对PVA-PEG-H2O体系凝胶动力学及膜性能的影响

考察了三元铸膜液PVA-PEG-H2O体系在丙酮-水混合凝胶剂、异丙醇(IPA)和四氢呋喃(THF)中的凝胶情况以及凝胶剂对膜微观结构、性能的影响。结果表明:该三元体系在丙酮中呈现瞬时分相行为,凝胶速率最快;当混合凝胶剂中丙酮的体积分数为0.6时,铸膜液体系出现延时分相迹象;在IPA和THF中呈现延时分相行为,凝胶速率基本相同。膜的微观结构表明:在上述凝胶剂中,PVA膜均形成蜂窝状孔。随着凝胶剂中H2O含量的增加,膜的纯水通量降低。在丙酮中形成的膜通量最高,而在IPA和THF中形成的膜通量很低。     

制备含羧基侧基聚芳醚酮酮树脂的初步探索(I)

通过偏苯三甲酸酐制备1，2，4－苯三甲酰氯，再以二苯醚（DPE）、1，2，4－苯三甲酰氯（TAMC）为单体，无水AlCl3/二氯乙浣（DCE）／N－甲基吡咯烷酮（NMP）为催化剂溶剂体系，在Friedel-Crafts亲电聚合条件下合成了含羧基侧基的聚芳醚酮酮树脂（PEKK），进行了耐溶剂性试验，测定了其酸值及粘度，同时利用X－射线衍射、IR、DSC、TG等分析技术研究了含羧基侧基的聚芳醚酮酮树脂（PEKK）的结构和性能。研究结果表明：该聚合物是可溶性无规低聚物，聚合物含有羧基侧基，可望成为耐高温性能分离膜、离子交换树脂，同时可作为交联聚合物、接枝聚合物及其它特种高分子材料的中间体，而且通过二元或三元聚合来改变交联点、接枝点的密度，为进一步得到结构多样化与性能各异的聚芳醚酮酮提供一个良好的基础。     

庚烷-苯-N-甲酰吗啉体系液液平衡研究

在常压,298.15,313.15,333.15,353.15 K 4个温度下,测定了庚烷-苯-N-甲酰吗啉三元体系的液液平衡数据,得到三元体系平衡相图,节点数据的实验可靠性用Othmer-Tobias和Bachman方程进行了检验,实验数据点用UNIQUAC和NRTL模型进行了关联,分别得出了庚-苯-N-甲酰吗啉体系的模型参数,结果表明2种模型都能对该体系进行较准确的预测,相比之下,NRTL更能拟合实验结果;同时从分配系数,分离因子和选择性对N-甲酰吗啉萃取苯的性能进行了研究.图12,表4,参14.     

色谱分离对三元复合体系界面张力的影响及对策

针对三元复合驱由于存在色谱分离现象而改变了体系原有性质的问题,利用实验室优选超低界面张力的三元复合体系进行填砂管流动实验,展开色谱分离对三元复合体系界面张力影响的研究。以"突破时间"和"产出时差"两个参数描述色谱分离程度,测定每次出口端采出液120min时的界面张力。研究表明:复合体系中的三种化学剂间存在色谱分离现象,聚合物最早突破,表面活性剂最后突破;表面活性剂与聚合物之间的色谱分离程度最明显,聚合物与碱之间的色谱分离程度最小;色谱分离使三元复合体系界面张力由10-3数量级增加到10-2数量级,影响了三元复合体系的驱油效果,因此降低表面活性剂在地层中的损失将成为降低色谱分离程度的主要措施。采用槐糖脂作为牺牲剂代替部分表面活性剂放在三元复合体系前注入地层,可以有效降低色谱分离的影响,更有效地提高最终采收率。     

PVA-PFSA/PAN渗透汽化膜强化乙酸乙酯酯化脱水及工艺过程模拟

以聚丙烯腈(PAN)中空纤维超滤膜为底膜,以酒石酸(Tac)为交联剂,制备了聚乙烯醇(PVA)与全氟磺酸(PFSA)共混复合膜,并用于乙酸乙酯-水、乙酸乙酯-乙醇-水溶液的脱水研究。考察了分离乙酸乙酯-水二元溶液时,料液温度和含水量对复合膜分离性能的影响;40℃下分离含水2%(质量分数,下同)的乙酸乙酯水溶液时,其总渗透通量81.1 g/(m2.h),分离因子为1 890;考察了复合膜用于分离乙酸乙酯-乙醇-水(质量比90∶2∶8)三元溶液时,料液温度的影响及脱水效果。结果表明:40℃时复合膜对三元溶液的总渗透通量可达251.0 g/(m2.h),此温度下,只需12 h就可将含8%初始水的三元溶液脱水至4.66%。PVA-PFSA/PAN渗透汽化膜对乙酸乙酯体系的脱水效果良好,可应用于强化乙酸乙酯酯化生产工艺。利用Aspen Plus 11.1软件对工艺流程进行了模拟,结果表明:在同等操作条件下,渗透汽化膜强化酯化工艺流程相对于普通的反应精馏,提高了乙酸乙酯的单程收率和原料的转化率,简化了乙酸乙酯生产流程。     

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.