茜素荧光猝灭法测定蛋白质

提出了一种荧光猝灭测定蛋白质的新方法 .茜素与牛血清白蛋白反应导致其荧光猝灭 .茜素的最大激发波长和发射波长分别在 4 6 5nm和 52 0 nm.在最佳实验条件下 ,牛血清白蛋白在 4 .5～ 10 0 μg· m L-1范围内成直线关系 .其检测限为 4 .5μg· m L-1,相对标准偏差分别为 4 .5% (30μg· m L-1牛血清白蛋白 )和 2 .6 % (6 0 μg· m L-1牛血清白蛋白 ) .     

改性绿茶对汞的吸附作用

采用原子吸收光谱法研究有机汞和无机汞的吸附作用。改性绿茶的用量为 2 5 mg、在 p H值 =7的溶液中搅拌 6 min,无机汞的吸附率达 95 % ,有机汞的吸附率不大于 5 % ;同等量的改性绿茶在 p H值 =1的溶液中搅拌9min,有机汞的吸附率可达到 90 %以上。 10次重复分离测定 0 .1μg· ml- 1汞溶液 ,测得无机汞、有机汞的检出限分别为 0 .0 6μg· L- 1 和 0 .0 8μg· L- 1 ,相对标准偏差为 8.6 %和 5 .8% ,回收率为 92 .5 %～ 10 5 .3%和 93.8%～ 10 6 .6 %。实验还表明 ,在盐酸浓度分别为 2 .0 mol· L- 1、6 min和 4 .0 mol· L- 1、11min,共存 KCl的量为 10 0mg,可定量解吸无机汞和有机汞     

单扫描示波极谱法测定煤中磷

磷和钼酸铵在酸性条件下与还原剂抗坏血酸作用 ,能形成具有电活性的磷钼杂多蓝配合物 ,此配合物在氨性缓冲溶液介质中 (p H:9.5～ 10 .4)产生一灵敏的还原波 ,磷在 0 .0 3μg· L- 1～ 1.5 μg· m L- 1范围内与波高呈线性关系 (r=0 .999)。用磷标准溶液进行标准加入回收测定 ,平均回收率为 98.6 %,RSD为 0 .2 %。该方法具有快速、方便、灵敏度高等特点 ,可用于煤中磷含量的测定。     

降低何首乌愈伤组织褐化研究

以何首乌为材料, 叶片愈伤组织为外植体, 采用L9 (34)正交设计, 研究不同因素对降低愈伤组织褐化的作用. 3因素为基本培养基(A)、培养基中活性炭(B)和硝酸银(C)浓度, 每因素设3个水平, A分别为MS, 1/2 MS和1/4 MS无机盐浓度, B分别为0 g·L-1, 5 g·L-1和10 g·L-1, C分别为5 mg·L-1, 0 mg·L-1和10 mg·L-1.外植体接种在不同的MS基本培养基中(含2,4 D 1 mg·L-1、琼脂8 g·L-1、蔗糖25 g·L-1, pH=5 8), 于(25±1) ℃、2 000 lx光照培养, 30 d后统计愈伤组织的褐化率. 试验结果表明: 降低愈伤组织褐化的最优水平组合为A2B3C1, B对试验结果的影响达显著水平(p<0 05). 以1/2 MS为基本培养基, 并于1/2 MS+活性炭10 g·L-1+AgNO3 5 mg·L-1培养基(附含2,4 D 1 mg·L-1)中培养, 褐化率可降至13 9%.     

钨酸盐-碱性染料-聚乙烯醇高灵敏光度法测定痕量锡的综合研究

报告一类光度法测定纳克量锡的新方法.在聚乙烯醇(PVA)存在下,锡(Ⅳ)与钨酸盐可分别和碱性染料罗丹明B(RB),丁基罗丹明B(BRB),耐尔蓝(NB)反应,形成离子缔合物,缔合物的最大吸收分别位于580nm(RB),565nm(BRB)和580nm(NB),表观摩尔吸光系数ε值分别为3.23×107L·mol-1·cm-1(RB),2.54×107L·mol-1·cm-1(BRB)和2.95×107L·mol-1·cm-1(NB).服从比耳定律的范围分别在0.4～2.0μg·L-1(RB),0～2.4μg·L-1(BRB)和0～2.0μg·L-1(NB),检出限(3σ)分别为0.031μg·L-1(RB,n=12),0.073μg·L-1(BRB,n=11)和0.083μg·L-1(NB,n=11).离子缔合物至少稳定72～240h.考查了40多种共存离子的影响,确立了测定痕量锡的酸度条件等.研究了缔合物的红外光谱,锡钨杂多络阴离子具有Keggin结构.方法均已用于某些合金钢和锌合金中痕量锡的测定,结果满意     

化学镀Ni-P-ZrO_2工艺及性能

以NiSO4 为施镀主盐 ,次亚磷酸钠为还原剂研究了化学镀法在工件表面获得良好性能的Ni P ZrO2 镀层的工艺 .用正交试验法确定了镀液的最佳成分 ,考察了施镀温度、搅拌速度、ZrO2 微粒的添加量对镀层形成的影响 ,并用X射线衍射和电子探针对镀层的结构进行了分析 .结果表明 ,镀液的最佳组成为 :NiSO4 30g·L-1,配合剂 18g·L-1,稳定剂 2g·L-1,次亚磷酸钠 2 0g·L-1,促进剂 15g·L-1;施镀工艺条件为 :施镀温度 85～ 90℃ ,ZrO2 微粒加入量 10～ 2 0g·L-1,在施镀过程中采用间歇式搅拌法 ;经过 30 0℃以下的热处理后镀层结构仍为非晶态结构 ,经过 30 0℃以上的热处理后 ,则变为晶体结构 ;用以上方法获得的镀层为高磷镀层 .此外 ,用浓度为 10 % (质量分数 )的盐酸检验镀层的耐蚀性 ,结果表明ZrO2 微粒的加入不会影响Ni P基质层的抗蚀性 .因此 ,采用本工艺能获得性能优良的Ni P ZrO2 合金镀层 ,且性能比Ni P镀层有显著提高     

Ru(Ⅲ)-KIO_4-偶氮氯膦体系催化分光光度法测定微量钌

在酸性介质中 ,微量 Ru( )的存在对 KIO4氧化偶氮氯膦 的褪色反应有明显的催化作用 .据此褪色反应建立了微量钌的催化光度分析法 ,方法的检出限为 2μg· L-1 ,Ru( )在 2 .0～35.0 μg· L-1之间有良好的线性关系 .反应在水相中进行 ,应用于贵金属精矿中钌的测定 ,结果满意 .     

新型高分子絮凝剂处理含油废水的研究

利用新型高分子絮凝剂聚酰胺胺类 (polyam idoam ine PAMAM)树形分子对油田含油废水处理进行研究 .研究表明 :该絮凝剂在用量非常低的情况下 (15～ 2 0 m g· L- 1 ) ,除油效果明显 ,废水含油量从处理前 32 0 m g· L- 1降至处理后 1mg· L- 1 ;该絮凝剂与天然高分子助凝剂 (可溶性淀粉、羧甲基纤维素等 )配合使用效果更好 ,用量可降低到 5 mg· L- 1 .     

极谱法连续测定痕量铅和镉

研究了Pb2+和Cd2+与KCI-酒石酸钠-三乙醇胺-明胶体系的二次导数极谱波.在pH=4.5的HAc-NaAc介质中,Pb2+和Cd2+分别于-0.46V和-0.64V电位处产生一良好的极谱波.峰电流与Pb2+和Cd2+的浓度分别在1×10-5～3×10-1 g·L-1和5×10-5～6×10-3 g·L-1范围内呈线性关系.Pb2+和Cd2+的检出限分别为1×10-7 g·L-1和5×10-7 g·L-1.本法准确、简便、快速、选择性高.已直接用于饮料中铅和镉的连续测定,同时也对酒及面粉样品进行了测定,回收率分别为99.9%～100.1%和97.0%～104.8%.     

催化动力学光度法测定痕量铁

基于酸性介质中三价铁离子对过氧化氢氧化百里香酚蓝褪色的催化作用 ,提出了催化动力学光度法测定痕量铁的新方法 .该方法的线性范围为 0～ 372 μg·L- 1 .检测限为 4 .7× 10 - 3μg·mL- 1 .将本法用于自来水、大米和玉米中铁的测定 ,获得满意结果 .     

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