超声波法制取叶绿素铜钠盐的工艺研究

研究以藜蒿叶为原料、用超声波法制取叶绿素铜钠盐的工艺.通过正交试验找出适宜工艺条件为:用藜蒿叶与提取剂[V(CH3CH2OH)∶V(CH3COCH3)=1∶1]为1∶10(W/V)提取20 min,5%NaOH溶液皂化20 min,20%CuSO4溶液铜代15 min,2%NaOH溶液成盐.按本工艺条件所得藜蒿叶的叶绿素铜钠产品符合国家标准(GB3262-82),产率为0.68%~0.78%.     

高效液相色谱法快速测定空气中苯并[a]芘

样品用乙腈经超声波提取,以V甲醇：V水=9：1为流动相,AgilentZorbaxSBC18色谱柱分离,荧光检测器检测,建立了超声提取一高效液相色谱法快速测定空气中的苯并[a]芘的方法．该方法操作简便、快速、试剂消耗少、准确可靠．     

莴笋叶叶绿素的提取工艺研究

通过单因素实验和正交试验确定了浸提溶剂种类、料液比、浸提温度和浸提时间,进行工艺优化.结果表明:用85%乙醇提取莴笋叶叶绿素的最佳工艺条件:料液比1∶7、浸提温度60℃、浸提时间2.0 h.影响莴笋叶叶绿素提取效率的主次因素顺序是:提取温度>固液比>提取时间.通过超声波辅助提取法和浸提法的比较,得出超声波辅助提取法提取具有速率快、效率高的优点.     

中心组合设计提取橘皮色素研究

以干燥的橘皮粉为原料,在超声波功率为320 W下对其色素进行提取.以色素相对得率为考察指标,考察了提取温度、乙醇浓度、提取时间、液料比4个因素对色素得率的影响.应用Design Expert 7.0软件中的Central Composite程序设计安排实验.实验结果表明,橘皮色素相对得率受到各个因素及其交叉的影响,通过分析得到超声波提取橘皮色素最佳工艺为：提取温度为40℃、乙醇浓度为70%(V/V)、提取时间为20 min、液料比10∶1,用此工艺对橘皮色素进行提取,橘皮色素相对得率高.     

HPLC测定冷浸法提取中成药中的甘草酸含量

报道了以 PC8为色谱柱 ,甲醇 :水 :醋酸 (5 7.0∶ 42 .6∶ 0 .4,V∶ V∶ V)为流动相 ,在 UV2 5 4nm为测定波长的条件下 ,利用外标法定量 ,建立了反相高效液相色谱法测定冷浸法提取自制的 (依据经典成方 ) 8种方剂和 12种市售中成药中甘草酸含量。实验表明 ,本法操作简便、快速、结果准确 ,适用于测定不同类型制剂中甘草酸的含量。     

超声波辅助提取紫苏中迷迭香酸条件的优化

研究采用超声波技术从紫苏中提取迷迭香酸的工艺条件.用正交实验L18（37）优化,硫酸亚铁比色法测定迷迭香酸得率.确定的最佳工艺条件：40%乙醇为提取剂,料液比为1∶60（m/V）,超声波输出功率为300W,提取时间为15min,占空比为50%,迷迭香酸提取得率为1.146%.     

贝类产品中软骨藻酸的HPLC检测方法

建立了高效液相色谱测定贝类产品中软骨藻酸的检测方法,具体过程为:样品先经甲醇浸提后,再用甲醇-水(V（甲醇）∶V（水）=1∶1）提取2次,合并提取液后用Zorbax SB300-C18柱(2.1 mm×250 mm,5 μm)进行分离,以乙腈-0.2%磷酸水溶液（含0.1%三乙胺）（V（乙腈）∶V（磷酸水溶液）=12∶88）为流动相于室温下等度洗脱,流速为0.25 mL/min,进样量20 μL,检测波长为242 nm.结果表明,在建立的提取方法和色谱条件下,软骨藻酸从复杂的样品基体中被分离出来,在0.02~1.0 mg/L质量浓度范围内具有良好的线性关系（r＞0.999）,样品的平均加标回收率为108%,测量方法的RSD为3.5%（n=6）,检出限为23.5 ng/g.所建立的检测方法可适用于对贝类产品中软骨藻酸的快速检测.     

GC-NCI-MS分析粮谷中多类农药残留

 建立了粮谷中14种农药残留（9种有机氯、3种拟除虫菊酯和2种含氯有机氮）气相色谱-负化学源-质谱（GC-NCI-MS）的分析方法,试样样品用V(正己烷)∶V(丙酮)=1∶1超声波提取,硅镁吸附剂净化,采用GC-NCI-MS选择离子扫描方式检测.结果表明,该方法准确、快速、选择性好、抗干扰能力强,14种农药的方法最低检出限：0.01～0.18?μg/kg,平均添加回收率在75.2%～109.7%之间,变异系数都小于10%,并成功应用于大米、面粉试样中痕量农药残留分析.     

柚皮总黄酮超声波辅助提取工艺的研究

采用超声波提取柚皮总黄酮,以乙醇为提取剂,探讨了影响柚皮总黄酮提取率的因素——超声时间、乙醇浓度、提取温度及液料比,通过正交试验确立了最佳提取工艺。结果表明:在60℃条件下,液料比(V(溶剂)∶m(柚皮))为20 mL/g,用70%(体积分数)的乙醇超声提取1 h时,柚皮总黄酮提取效果最好,此条件下总黄酮的质量分数为0.66%。     

喜树嫩叶中喜树碱的HPLC提取方法的选择

建立一种从喜树嫩叶中喜树碱的高相液相测定提取方法.采用Waters Symmetry C18(150×3.9 mm,5μm)高效液相色谱.乙腈∶水=35∶65(V/V)为流动相,1.0 mL/min的流速,检测波长254 nm,柱温:25℃,进样量10μl.以不同浓度的甲醇提取法与不同浓度的碱法作对比,结论:以80%甲醇为溶剂于50℃下超声提取1 h为最佳提取法.     

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