硒-2,3-二氨基萘-β-环糊精-十二烷基磺酸钠荧光体系测定痕量硒

利用β 环糊精 (β CD)和十二烷基磺酸钠 (SLS)对Se与 2 ,3 二氨基萘的反应产物 4 ,5 二苯基并硒二唑 (记作Se DAN)的协同增敏作用 ,直接在水相中测定痕量硒 .最佳pH为 5～ 8,λex=3 79nm ,λem=540nm .Se含量在 0～ 0 .6μg/mL范围内与荧光强度成线性关系 .最低检出限 0 .0 0 1 μg/mL ,试验了多种常见离子的影响 ,干扰可以很好地消除     

反相高效液相色谱法测定两栖动物组织中还原型谷胱甘肽的含量

建立反相高效液相色谱法(RP-HPLC)并测定黑斑蛙(Rana nigromaculata)和中华大蟾蜍(Bufo bujfogargarizans)幼体与成体组织中GSH含量。样本处理后经高氯酸沉淀,采用邻苯二甲醛(OPA)柱前衍生,338nm波长检测,以甲醇-乙酸盐缓冲液为流动相,测得GSH标准液浓度在25~300μmol/L范围内与峰面积有良好线性关系,相关系数达0.999。GSH外标回收率为99.44%±2.22%,日内和5日日间变异系数(CV)为≤2.21和≤2.35,最低检出限1.1μg/g。结果黑斑蛙和中华大蟾蜍幼体与成体GSH均为皮肤含量最高,达213.4、197.3μg/g和189.7、201.9μg/g,其次为肝脏、脑、全血、脾脏,肌肉组织含量最低,为51.3、16.2μg/g和40.3、14.9μg/g。本方法样本处理简单且具有良好检测灵敏度和精密度,能够满足两栖动物组织GSH含量测定要求。     

高效液相色谱法测定硒-甲基硒代半胱氨酸

建立硒-甲基硒代半胱氨酸(SeMC)测定方法,优选合成工艺,控制成品质量。采用高效液相色谱法(HPLC),测定条件为:色谱柱为HypersilC4(4.6mm×300mm,5μm),流动相为水(用磷酸调至pH2.50)-甲醇(95:5),检测波长235nm,流速1.0ml/min,柱温25℃。结果:硒-甲基硒代半胱氨酸的线性范围为0.08μg～2μg,r=0.9995,高、中、低三种不同浓度的平均加标回收率范围为99.97%～100.62%,RSD为0.53%～0.88%。结论:该法操作便捷,结果准确,适合合成工艺评价和成品质量控制。     

紫草素体外抗菌活性的实验研究

目的:本文主要研究紫草主要成分紫草素体外抗菌活性及其抗菌谱.方法:用琼脂平板法测定紫草素的抗菌谱;以左氧氟沙星为阳性对照药,通过试管二倍稀释法检测紫草素最低抑菌浓度(MIC)和最低杀菌浓度(MBC).结果:紫草素对多种常见菌株包括革兰阳性菌、革兰阴性菌以及真菌显示出抗菌作用,对金黄色葡萄球菌(MIC为6.25μg·mL~(-1),MBC为25.0μg·mL~(-1))、大肠埃希菌菌(MIC为12.5μg·mL~(-1),MBC为25.0μg·mL~(-1))、白色念珠菌(MIC为1.563μg·mL~(-1),MBC为3.125μg·mL~(-1))、蜡状芽孢杆菌(MIC为1.563μg·mL~(-1),MBC为6.25μg·mL~(-1))、沙门氏菌(MIC为25.0μg·mL~(-1),MBC100.0μg·mL~(-1))的生长有显著的抑制作用.抗菌能力与左氧氟沙星相当.结论:紫草素具有良好的抗菌作用,具有成为抗菌药物先导化合物的条件.     

HPLC测定药品中多贝斯的含量

采用hypersil ODS-C18色谱柱(150×4.6 mm,5μm);以甲醇-水=70:30(V/V)为流动相,流速为1.0 mL/min,柱温为室温,检测波长为301 nm,外标法测定了多贝斯胶囊中多贝斯的含量.多贝斯在1～60μg/mL浓度范围内,峰面积(A)与浓度(C)呈现出良好的线性关系,回归方程为A=-3 019.9 7 127.9 C(μg/mL)(r=0.999 6),此方法的最低检出限为0.1μg/mL.多贝斯在水溶液和尿液中的回收率分别在97.20%～101.0%和97.90%～101.5%之间,重现性良好.本法准确、简单、快速,可应用于药物制剂中多贝斯的质量监控.     

硒(Ⅳ)-碘化物-维多利亚蓝4R体系共振瑞利散射、二级散射和倍频散射法测定痕量硒(Ⅳ)

在0.16～0.32 mol/L的盐酸溶液中, 维多利亚蓝4R(VB4R)的共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(MFS)均十分微弱. 在过量碘化物存在下, 当硒(Ⅳ)氧化I-形成I-3配阴离子并进一步与VB4R反应形成离子缔合配合物时, 3种散射均大大增强并产生相应的散射光谱. 最大RRS波长位于582 nm, 另在320 nm, 410 nm, 452 nm, 470 nm, 800 nm和940nm处有强度较低的RRS峰;此时最大SOS峰位于810 nm, 并在650 nm和940 nm有两个较小的SOS 峰,而最大MFS峰位于405 nm并在320 nm和475 nm处有两个较小的MFS峰. 在各自的最大散射波长处, 硒(Ⅳ)在0～1.0μg/25 mL(RRS和MFS法)和0～1.5μg/25 mL (SOS法)的浓度范围内与散射强度ΔI成正比. 方法有很高的灵敏度, 对硒(Ⅳ)的检出限分别为0.24 μg/mL (MFS),0.48 μg/mL(RRS)和 0.60 ng/ml(SOS). 3种散射法均可用于痕量硒(Ⅳ)的测量.     

催化光度法测定痕量硒

研究了砸(Ⅳ)对SnCl_2还原Fe(Ⅲ)-酒石酸络合物反应的催化作用,建立了测定痕量硒的方法.在pH 2.25条件下控制反应为假一级反应的条件,在波长336nm处用光度法测定.工作曲线的线性范围为0.006μg/mL～0.048μg/mL,用此法测定水和土壤样品中的硒含量,结果满意.     

O—FPF—CTMAB荧光光度法测定水中微量钼的研究

研究了荧光光度法测定微量钼的新方法．在0．04～0．24mol.L^-1的盐酸介质中,邻氟苯基荧光酮(O-FPF),溴化十六烷基三甲铵(CTMAB)和钼M0(Ⅵ)形成无荧光的三元配合物,从而导致体系的荧光熄灭,在激发波长λcm=365nm和发射波长λcm=529nm时,钼含量在0-3．0μg／25mL范围内,荧光熄灭值△F和钼浓度成正比．方法灵敏度高,检出限为2．0μg／L．用于水样中微量钼的测定,结果满意．     

硒对蛭石培养大豆生理生化特性的影响

采用蛭石培养大豆,并施以不同浓度的硒处理,对大豆的表观性状、生物学性状、生理性状进行了研究.结果表明,蛭石中补以适宜浓度的硒,能够促进大豆植株生长,硒浓度过高,大豆的生长会受到抑制;可溶性蛋白和可溶性糖的含量均较对照组有所提高,一定浓度的硒能够增强大豆的抗逆性能;蛭石中硒浓度高于5μg.mL-1时,脯氨酸含量上升,提高了大豆的抗逆性,而硒浓度在0.1～5μg.mL-1范围内时,MDA含量均低于对照,补硒浓度达到10μg.mL-1时,MDA的含量高于对照和低浓度硒处理,所以低浓度的硒(补硒浓度小于10μg.mL-1)有利于降低过氧化产物MDA的生成,对大豆有一定的抗氧化作用;当硒浓度低于10μg.mL-1时,叶绿素含量均高于对照组,说明适量的硒有利于促进光合作用,从而利于大豆的生长.     

高效液相色谱法测定冰茶栓中的咖啡因

本叙述了应用HPLC法对戒毒新药冰茶栓中咖啡因含量的测定方法，样品经1：1的乙醚-石油醚溶化，用1：1的甲醇水溶液提取，用20mmol／1醋酸铵缓冲液和甲醇(80：20)作为流动相，经ODS-C18柱分离，紫外270nm检测，加标平均回收率为98．22％，相对标准偏差(CV)日内为0.30％，日间为0．97％，最低检出浓度为25μg/L，最低定量浓度为100μg/L，线性范围为10～250μg／mL，相关系数为0．9999。     

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.     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-