超声波提取及其快速检测土壤中的甲苯

以合成土样为对象,研究了超声波辅助提取甲苯的条件及其提取效率,由此建立了土壤中甲苯含量的快速制样方法。在中档超声波场辐射下,30mL丙酮-正己烷（体积比1：1）分两次萃取10．0g合成土样中的甲苯时所获收率最高。在选定条件下,用于实际土样分析,以索氏萃取4h的结果为基准,本方法的平均回收率为101．0％,RSD为1．5％。     

超声波提取甘油的实验研究

以棉籽油脱臭馏出物为原料,研究用超声波提取甘油的方法．经五元二次正交试验得到甘油的最佳提取条件是：超声波功率为85-150W,催化剂为0．044％～0．048％甲醇钠,超声时间为20-25min,超声波温度为60-70℃,醇油比为0．328-0．355mL／g．建立的甘油得率模型经实验验证拟合良好,预测准确．     

超声波提取黄芪中总黄酮工艺研究

研究比较了超声波法、微波法、乙醇提取法等工艺提取黄芪总黄酮的效果,得出超声波法提取黄芪总黄酮的工艺最佳．以提取温度、提取时间、料液比、乙醇体积分数为考察因素,黄芪总黄酮提取率为考察指标,采用止交试验法优化黄良总黄酮提取工艺．结果表明,最佳工艺条件为：超声波提取温度为65C、提取时间30min、料液比为1：15（g／mL）、乙醇体积分数为65％,总黄酮的提取率为0．418％,是微波提取法的1．31倍,乙醇提取的1．69倍．     

蒙药广枣、麻黄、锦草中总黄酮的提取及含量的测定

本实验以乙醇为溶剂,超声波辅助提取广枣、麻黄、锦草中总黄酮,利用分光光度法测定总黄酮的含量,并测定其回收率．结果表明：广枣黄酮含量为11．6mg／g,RSD：0．89％;麻黄黄酮含量为37．3mg／g,RSD：0．97％;锦草黄酮含量为15．4mg／g,RSD：1．23％．三种样品的回收率在94．1％～96．35％之间．     

穿山龙多糖分离纯化工艺的研究

以粗多糖得率为指标，比较水醇法、水提ZTC吸附澄清剂法和超声波法三种提取方法，并以穿山龙多糖含量为指标，考察采用水醇法提取穿山龙多糖时，回流时间、固液体积比，提取次数对多糖含量的影响；同时，用硫酸-苯酚法对穿山龙粗多糖中的多糖含量进行了测定．实验结果表明，水醇法提取的多糖得率高于水提ZTC吸附澄清剂法和超声波法，分别提高6．0倍和6．6倍．水醇法的最佳提取工艺条件：回流提取时间90min，液料比1：10，提取次数3次．     

杨梅渣红色素的超声提取和微胶囊化工艺研究

研究了杨梅渣红色素的超声提取和微胶囊化工艺．通过正交实验确定了杨梅渣红色素超声提取的最佳工艺条件：料液比为1：12g·mL^-1,pH=1,提取时间为40min,超声波功率为400W．通过单因素实验确定了杨梅渣红色素微胶囊化的工艺条件：壁材阿拉伯胶与麦芽糊精的比例为1：3,芯壁比为1：14,乳化剂蔗糖脂肪酸酯的含量为0．6％,黏稠剂普鲁兰多糖的含量为0．5％．稳定性实验表明杨梅渣红色素经微胶囊化后耐热、耐酸、耐光性显著提高．     

氯苯类化合物在CTMAB-高岭土上的吸附机理

目的 探讨氯苯类化合物在CTMAB-高岭土上的吸附机理.方法 采用一系列用阳离子表面活性剂CTMAB改性的有机高岭土对氯苯、1,4-二氯苯、1,2,4-三氯苯和1,2,4,5-四氯苯等4种氯苯类化合物的吸附性能及机理进行研究.结果 CBs在CTMAB-高岭土上的吸附等温线为线性;对于不同改性量的CTMAB-高岭土来说,CBs在CTMAB-高岭土上的Koc值基本为一常数,比其在土壤中的Koc值要高出许多;其Koc与CBs的辛醇-水分配系数呈正相关,而随CBs在水中溶解度的增大而降低.结论 吸附过程主要是CBs在CTMAB-高岭土有机相中的分配作用所致,CT-MAB-高岭土对CBs的吸附能力与有机物本身的性质密切相关,这对受污染的土壤和地下水的修复工艺意义重大.     

蓖麻碱的超声波辅助提取及其抗氧化性能

以蓖麻粕为原料,采用超声波辅助提取法,在单因素试验的基础上,利用正交试验优化蓖麻碱提取工艺条件,并初步研究蓖麻碱的体外抗氧化性能。结果表明:超声波提取蓖麻碱的最佳条件为超声波功率300 W、料液比1∶10 g/m L、提取时间30 min、提取温度80℃。在优化条件下蓖麻碱的提取率为80.15%;蓖麻碱对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除能力较强,对2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二胺盐自由基(ABTS·)具有一定的清除能力,对Fe3+具有一定的还原能力。蓖麻碱质量浓度为10 mg/m L时,DPPH·的清除率达到71.35%。     

超声波提取陕北红枣多酚

研究超声波法提取陕北红枣中多酚的最佳提取条件。(1)考察了红枣多酚提取的最佳方法和最佳溶剂;(2)考察超声提取时间、溶剂浓度、料液比三个因素对多酚提取率的影响。并在单因素实验的基础上设计L9(33)正交实验。结果:最佳方法为超声波提取>索式提取>普通回流>室温浸提。提取溶剂为乙醇。提取陕北红枣中多酚的最佳工艺条件组合为:70%(V/V)乙醇、料液比为1∶40、超声提取30 min、提取3次。多酚得率为444.6 mg/100 g。由几种提取方法比较,可知超声波提取有明显的优势:提取时间短、温度低、不会使多酚分解且操作简单。     

响应面法优化槲蕨总黄酮提取工艺及其抗氧化活性

为了优化槲蕨总黄酮的提取工艺并研究其抗氧化活性,该文以料液比、乙醇体积分数、超声处理功率和超声辅助提取时间为考察因素,以槲蕨总黄酮产率为研究目标,在单因素实验的基础上运用响应曲面分析法优化槲蕨总黄酮的提取工艺,并探讨了超声波提取的槲蕨总黄酮的抗氧化活性.研究结果表明：超声波辅助乙醇提取槲蕨总黄酮的最佳工艺是料液比为1∶30.00(g·mL^-1)、超声功率为450.00 W、乙醇体积分数为68.00%,在该优化条件下槲蕨总黄酮的产率为1.452 mg·g^-1.抗氧化研究表明：槲蕨总黄酮对羟自由基、1,1-二苯基-2-三硝基苯肼自由基(DPPH·)和超氧阴离子(O^-₂·)具有较强的清除能力,这说明槲蕨总黄酮具有良好的抗氧化活性.     

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.     

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.     

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.     

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.     

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.     

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that