真空膜蒸馏法处理NaCl水溶液超疏水性PVDF膜性能的优化

采用正交实验设计方法,以纯水和0.03 g/L NaCl水溶液为料液,依据真空膜蒸馏(VMD)实验特性,选择了聚偏氟乙烯(PVDF)超疏水微孔膜的优化制备条件。结果表明由直观分析法和直接测量法分别确定的优化制膜条件基本一致。用于VMD的PVDF微孔膜的优化制膜条件为:铸膜液体系组成及质量分数为15%PVDF/51%TEP-34%DMAc,第1凝固浴中混合溶剂(TEP-DMAc)总质量分数为60%,膜厚度为0.17 mm,第1凝固浴中TEP与DMAc的质量比为60∶40;在该条件下,NaCl的脱除率可达99.90%以上。     

凝固浴和铸膜液对新型纤维素超滤膜的影响

以纤维素为原料,NMMO为溶剂,用相转化法制备超滤膜,并研究了凝固浴浓度、温度、有机醇作凝固剂及铸膜液浓度对膜性能的影响。     

基于相转化法的成膜条件对聚砜膜结构的影响

采用相转化法制备聚砜超滤膜,分别以甲醛溶液、乙醇溶液、DMAC溶液、蒸馏水以及自来水作为凝固浴,含量均为5%.并在其他因素不变的条件下,控制聚砜膜空气中停留时间,并对聚砜超滤膜的断面结构以及表面结构进行了测试及表征.结果表明,使用水作为凝固浴组成时膜的选择性最好,断面结构分布均匀;空气中停留时间为15秒时选择性较好,指状孔结构分布均匀.     

柴油脱酸溶剂回收用聚酰亚胺纳滤膜的制备和分离性能

针对醇氨法脱除柴油中环烷酸技术存在的溶剂回收过程能耗大的问题,制备出聚酰亚胺纳滤膜以分离环烷酸和溶剂,考察了铸膜液表观黏度、铸膜液挥发时间、凝固浴组成等膜制备工艺对膜通量和截留率的影响,同时考察了抽提液中环烷酸盐质量分数和操作压力等使用条件对膜分离性能的影响规律.结果表明:所得纳滤膜的通量超过17 L·m-2·h-1,截留率超过50%;使用黏度为310 mPa·s的铸膜液、在60 s铸膜液挥发时间、使用纯乙醇为凝固浴可得到综合性能最佳的纳滤膜;提高抽提液中环烷酸盐质量分数,膜通量下降,但对截留率基本无影响;升高操作压力,膜通量和截留率均增大.     

NMMO工艺纤维素超滤膜的研究

以纤维素为原料,ＮＭＭＯ为溶剂,用相转移法制备超滤膜,并研究了凝固浴浓度,温度、有机醇作凝固剂及铸膜液浓度对膜性能和结构的影响。     

软木纤维素蒸汽闪爆改性后成膜性能

利用蒸汽闪爆对软木纤维素进行活化,然后直接溶解在质量分数为9.5%的NaOH和质量分数为1.0%的尿素混合溶液中,采用质量分数为2%～25%的H2SO4作为凝固浴进行成膜实验.通过X射线衍射、红外分析、扫描电镜和拉力测试等对所制备的膜进行分析,结果表明:成膜后纤维素晶型由Cell-Ⅰ转变为Cell-Ⅱ,所制备的膜为多孔膜,孔径可以通过改变凝固浴的质量分数而得到相应调整,且表面孔径大于内部孔径.质量分数为5%的H2SO4为最佳凝固浴,得到具有最大拉伸强度88.7 Mpa和断裂伸长率4.1%的纤维素膜.     

高性能聚氨酯多孔支撑膜的研制

采用溶液相转换法制备聚氨酯（PU）多孔支撑膜，通过改变聚氨酯制膜液中聚氨酯含量、添加剂颗粒大小及含量、溶剂的组成、凝固浴的组成，研究了PU多孔支撑膜的制备条件与多孔支撑膜性能的关系。研究结果表明，制膜液中聚氨酯和添加剂含量对膜性能影响较大；使用混合溶剂可有效改善膜的孔结构，提高支撑膜的性能；控制凝胶浴中溶剂含量，可进一步提高聚氨酯支撑膜的性能稳定性。     

明胶包埋壳聚糖/海藻酸钠茶多酚的缓释性能

以海藻酸钠和壳聚糖为壁材制备了茶多酚微胶囊,确定了最佳制备工艺条件为壳聚糖质量分数1．0％、海藻酸钠质量分数2．0％～3．0％、氯化钙质量分数5．0％,所制得的茶多酚微胶囊的包埋率最大,用明胶包埋茶多酚微胶囊,制备了茶多酚缓释复合体系,结果表明,用明胶包埋后的微胶囊可使茶多酚的缓释性能及稳定性有较大的提高。     

锐孔法制备玉米胚中还原型谷胱甘肽微胶囊

以玉米胚中还原型谷胱甘肽为芯材,以海藻酸钠为壁材.采用锐孔法制备微胶囊,以包埋率为指标,确定最佳工艺条件:操作温度为50 ℃,海藻酸钠的质量分数为2.0%,壁材与芯材的比例为20:1,乳化剂的质量分数为0.2%,凝固液CaCl2的质量分数为2.0%,包埋率高达54.46%.由此可见微胶囊化还原型谷胱甘肽有利于提高其稳定...     

NMMO工艺纤维素膜结晶结构

以纤维素为原料,N-甲基吗啉-N-氧化物(NMMO)为溶剂,采用相转化法制备非对称纤维素膜.利用X-射线衍射法对该工艺纤维素膜的结晶结构进行分析,讨论了铸膜液浓度、凝固浴温度及添加剂对膜结晶度的影响.结果表明:纤维素Ⅰ在NMMO.H2O中溶解并固化成膜后,得到的是纤维素Ⅱ,而不能形成纤维素Ⅰ;提高铸膜液中纤维素浓度、凝固浴温度及抗氧化剂(没食子酸丙酯)用量都可使该工艺纤维素膜的结晶度增大,添加少量的NH4Cl致使纤维素膜的结晶度有所下降.     

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.