CO2超临界流体萃取法提取竹叶黄酮的研究

以芦丁为定量依据,采用正交设计法考察了CO2超临界流体萃取竹叶中黄酮的工艺条件。结果表明,影响CO2超临界流体提取的主要因素依次是：萃取压力、萃取温度、夹带剂的用量、萃取时间;确定了最佳提取条件为：萃取压力40Mpa、萃取温度60℃、萃取时间60min、夹带剂的用量1mL/g.竹叶总黄酮的提取量为4.978 mg/g.     

应用超临界CO2萃取当归中挥发油的研究

研究超临界CO2流体萃取当归中的挥发油的工艺.方法:用正交试验等方法,研究药材粒度、萃取温度、萃取压力、萃取时间及解析分离条件对超临界CO2流体萃取挥发油的影响.结果:超临界CO2流体萃取挥发油的最佳工艺条件:原料粒度40目,萃取温度40℃,萃取压力25MPa,萃取时间2h,CO2流量20L/h,分离釜Ⅰ压力8MPa,分离釜Ⅰ温度50℃;分离釜Ⅱ压力6MPa,分离釜Ⅱ温度50℃.结论:优选得到的工艺具有较高的提取率,该工艺合理、可行.     

超临界CO2萃取薰衣草挥发油的工艺研究

为建立超临界CO2萃取薰衣草挥发油的最佳工艺条件。以挥发油萃取率为指标,选取萃取压力、萃取温度、CO2流量和萃取时间作为影响因素,通过正交试验法L9（3^4）确定了超临界萃取薰衣草挥发油的最佳提取工艺条件。最佳工艺为CO2流量25L／h,萃取温度45℃,萃取压力22MPa,萃取时间1h,挥发油提取率为4．497％。水蒸气蒸馏法提取4h,挥发油提取率为1．32％。因此可知,超临界萃取薰衣草挥发油的收率高,萃取时间短。     

分子蒸馏提取橘皮中D-柠檬烯工艺的研究

利用超临界CO2萃取橘皮中的挥发油,从中分离得到D-柠檬烯,本文对比提取工艺、条件进行研究.超临界流体提取橘皮中D-柠檬烯的最佳工艺条件为:CO2超临界萃取150 min,萃取压力25 MPa,CO2流量20 L/h,萃取温度46℃.     

花椒挥发油的超临界CO-2萃取工艺研究

介绍了超临界CO2萃取花椒挥发油的提取分离工艺,重点研究了原料粒度、前处理浸提时间、超临界CO2萃取温度、萃取压力、CO2体积对萃取率的影响. 应用正交实验优化出;影响超临界CO2萃取的主次因素为萃取温度＞CO2体积＞压力;最佳工艺参数为;原料粒度以60目(0.28mm)为宜,前处理浸提时间40min,萃取温度55℃,萃取CO2体积为30ml,萃取压力为34.475MPa,得到花椒挥发油的萃取率高达13.20%.     

花椒挥发油的超临界CO_2萃取工艺研究

介绍了超临界CO2萃取花椒挥发油的提取分离工艺,重点研究了原料粒度、前处理浸提时间、超临界CO2萃取温度、萃取压力、CO2体积对萃取率的影响.应用正交实验优化出:影响超临界CO2萃取的主次因素为萃取温度>CO2体积>压力;最佳工艺参数为:原料粒度以60目(0.28mm)为宜,前处理浸提时间40min,萃取温度55℃,萃取CO2体积为30ml,萃取压力为34.475MPa,得到花椒挥发油的萃取率高达13.20%.     

响应面优化超临界CO2萃取花生油工艺研究

为了获得CO2流体萃取花生油的较佳工艺条件,通过单因素实验及响应面优化试验研究了萃取压力、萃取温度、CO2流量、萃取时间和花生仁粒度等因素对花生油萃取率的影响,确定了超临界CO2萃取花生油的较佳工艺参数为,萃取压力24 MPa,萃取温度43℃,花生仁粒度20目,CO2流量20 L/h,萃取时间110 min,在该工艺条件下花生油萃取率达到96.16%.对SFE-CO2流体萃取的花生油脂肪酸成分进行分析,结果显示,SFE-CO2流体萃取的花生油不饱和脂肪酸(主要是亚油酸和油酸)含量高达78%以上,符合一级花生油的标准(GB 1534—2003).     

黑豆中大豆异黄酮超声波法提取工艺优化

为了提高黑豆中大豆异黄酮的提取率,采用超声提取法,以乙醇水溶液为提取溶剂,选择乙醇浓度、提取时间、提取温度及物料粉碎度进行四因素三水平的正交实验,考察各提取因素对黑豆中大豆异黄酮提取率的影响,以优选出黑豆中大豆异黄酮的最佳提取工艺。结果表明,物料粉碎后过20目筛,以60%乙醇水溶液为溶剂,温度为50℃,超声提取50 min,大豆异黄酮的提取率为1.91%,为最优提取工艺,工艺重复性良好。     

超临界CO_2和微波辅助萃取当归挥发油

考察当归挥发油的不同提取方法.文中用超临界CO2流体萃取法和微波辅助萃取法研究萃取当归挥发油.实验表明:超临界CO2萃取最佳工艺条件为萃取压力25 MPa、分离釜Ⅰ解析温度55 ℃、萃取温度45 ℃,提取率约1.9%;微波辅助萃取最佳工艺条件为无水乙醇为提取溶剂,微波功率800 W、微波辐射时间150 s、液料质量比为4.71: 1,提取率约11.2%.微波辅助萃取法取得当归油的收率高于超临界CO2萃取法.微波辅助萃取法萃取当归挥发油收率高,但外观品质较超临界萃取的当归挥发油差.     

超临界CO2提取青蒿素的工艺

研究了超临界CO2提取青蒿素的工艺,考察了粒度、压力、温度、时间、CO2流量等影响因素.以萃取率为目标,综合考虑产品收率,优化了超临界萃取工艺条件,得到较佳的操作条件:萃取压力20 MPa,萃取温度50℃,每千克原料CO2质量流量1 kg/h,分离器Ⅰ的温度为60℃,压力为14 MPa.在优化条件下萃取4 h,萃取率达到95%以上,萃取物纯度在15%以上.     

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.