中华猕猴桃蛋白酶在甲醇溶液中的构象与活力变化研究

研究中华猕猴桃蛋白酶在不同浓度（Ｖ：Ｖ）甲醇存在下的内源荧光发射光谱、紫外差光谱及ＣＤ光谱的变化，并测定相应的活力变化；酶的内源荧光强度随甲醇浓度的增加而增高，且发射峰略有红移．在甲醇存在下，酶的紫外差光谱在２２５～２３５ｎｍ范围内出现正峰，随甲醇浓度增高，峰强度增大，且峰位蓝移．ＣＤ谱变化表明，在不同浓度甲醇存在下，酶的ａ──螺旋度有不同程度的减少．在１０％～５０％甲醇存在下，酶有不同程度的激活现象，当甲醇浓度为３０％和４０％时，激活程度最大，约为天然酶活力的１５０％．     

中华猕桃蛋白酶在甲醇溶液中的构象与变化研究

研究中华猕桃蛋白酶在不同浓度（Ｖ：Ｖ）甲醇存在下的内源荧光发射光谱，紫外差光谱及ＣＤ光谱的变化，并测定相应的活力变化，酶的内源荧光强度随甲醇深度的增加而增高，且发射峰略有红移。在甲醇存在下，酶的紫外差光谱在２２５～２３５ｍｎ范围内出现正峰，甲醇浓度增高，峰强度增大，且峰位蓝移。ＣＤ谱变化表明，在不同浓度甲醇存在下，酶的ａ－－螺旋度有不同程度的减少。在１０％－５０％甲醇存在下，酶有不同程度的激活现象     

乙醇对鲍鱼碱性磷酸酶活力与构象的影响

以乙醇为效应物研究对鲍鱼碱性磷酸酶(ALP)活力影响的结果表明．酶的剩余活力随着乙醇浓度增大而迅速下降，乙醇浓度40％可使酶活力完全丧失．说明乙醇对鲍鱼ALP有明显的失活作用，JG50为13％．含较低浓度乙醇(30％)的失活过程是可逆的反应．测定乙醇对酶的失活作用机理．结果表明乙醇对鲍鱼ALP的失活作用是非竞争性机制，说明底物存在不影响乙醇对酶的失活作用．应用荧光光谱、紫外吸收光谱研究鲍鱼ALP经乙醇微扰后的分子构象变化，发现乙醇对酶分子构象有显的影响，酶的内源荧光强度随乙醇浓度增大而增强．荧光发射峰逐渐发生红移．紫外吸收光谱在276nm吸收峰随乙醇浓度增大而增强．这些结果表明．酶蛋白分子中的生色基团残基的微环境发生变化．     

无花果蛋白酶分子去折叠与催化功能

应用光谱法研究无花果蛋白酶（ＥＣ．３．４．４．１２）在不同浓度脲及ＬＤＳ存在下的结构变化和活力变化的关系。荧光光谱显示，在１－６ｍｏｌ／Ｌ脲范围内，荧光强度均比天然酶高，但剩余活力只有天然酶的２０％以下，随脲浓度增大，α螺旋度有不同程度的增加，酶在低浓度（０．５ｇ／Ｌ）ＬＤＳ作用下，荧光强度下降，发射峰红移，在高浓度ＬＤＳ作用时，荧光强度增强，发射峰基本保持不变，活力则随着ＬＤＳ浓度增大而下降，甚     

文昌鱼酸性磷酸酶在甲醇溶液中的构象与活力变化

文昌鱼酸性磷酸酶（ＡＣＰａｓｅ，Ｅ．Ｃ３．１．３．２）是一种含有铁离子的金属酶，其可见光谱中５００ｎｍ的吸收峰以及荧光５１５ｎｍ的发射峰为该酶分子含铁的特征峰，与酶活力关系密切．通过荧光发射光谱和紫外可见光谱对该酶在不同浓度甲醇溶液中的构象与活力变化进行研究．不同浓度（Ｖ／Ｖ）的甲醇对酶活力有明显的抑制作用，动力学分析表明甲醇对酶的抑制为非竞争性抑制，其抑制常数为２０％．还研究了在甲醇存在下ＡＣＰａｓｅ活力中心的构象与活力变化，结果表明其构象变化快于活力变化．     

脲对果菠萝蛋白酶的变性与失活动力学

以脲为变性剂,以荧光光谱为监测手段,对果菠萝蛋白酶(Fruit bromelain)的分子构象变化进行研究,酶的荧光强度随脲浓度增大而递增,发射峰出现红移。荧光偏振在 230～240 nm及 260～290 nm 出现二个负峰,后者较为显著,并随脲浓度增大而加剧。脲对酶水解N-苄氧羰酰 L-赖氨酸对硝基酚酯(CBZ-Lys·pNP)活力的影响,表现为非竞争性抑制类型;比较脲对游离酶(E)及结合酶(ES)的失活速度常数。结果二者相等,底物不表现保护作用。测定酶在不同浓度脲中的变性速度常数和失活速度常数,比较了酶的构象变化及催化活力的关系,酶的失活速度常数比变性速度约大6～16倍。说明酶活性中心对脲的敏感性,酶活力的表现很大程度上依赖于酶构象的稳定性和完整性。     

β-环糊精对双酚A分子识别作用的表征研究

运用紫外光谱、红外光谱、荧光光谱、H核磁共振谱研究了β-环糊精对双酚A的分子识别行为,结果表明:双酚A经分子识别后其紫外吸收有所增加,吸收峰发生2~3 nm红移;红外特征峰被β-环糊精不同程度掩盖,且特征吸收峰都在不同程度发生一定的偏移;荧光强度随β-CD浓度的增大而逐渐增强;β-环糊精与双酚A形成稳定1:1的包结物,包结物常数为1.84×104L·mol-1,双酚A从β-环糊精的大口端部分进入其空腔.       

在胍溶液中文昌鱼酸性磷酸酶活性部位的构象变化与活力变化的关系

盐酸胍中酸性磷酸酶活性部位构象变化与活力变化的关系，酶于０．６ｍｏｌ／ＬＧｕ－ＨＣｌ中，其相对活力提高２０％，当ＧＵ－ＨＣｌ浓度增加到１．２～２．４ｍｏｌ／Ｌ时，酶的相对活力，其活性部位紫外－可见光谱５００ｍｍ处吸收峰及荧光发射光谱５１５ｍｍ处的发射峰值下降，同时测定了酶的变性与失活常数，也研究了酶的重折叠与复性的关系     

文昌鱼酸性磷酸酶在变性剂变性时的构象及活力变…

十二烷基硫酸锂（ＬＤＳ），脲（Ｕｒｅａ）等变性剂作用于ＡＣＰａｓｅ，以荧光法跟踪该酶的构象变化，随着ＬＤＳ浓度提高荧光强度下降但发射峰没有位移，而在Ｕｒｅａ中，荧光强度随着变性剂浓度上升而下降，发射峰明显红移，由３３０－３５０ｎｍ。分别测定其变性及失活的动力学常数，比较酶构象及催化活力的关系，结果表明：变性与失活为快相和慢相的一级反应，在ＬＤＳ作用下，失活速度大于变性速度，属于快活力慢构象变化的…     

杂色鲍碱性磷酸酶在DMSO溶液中的活力与构象变化的研究

以二甲亚砜（DMSO）为效应物．研究其对杂色鲍碱性磷酸酶（ALP）活力的影响，结果表明：该酶的剩余活力随着DMSO浓度增大而迅速下降，当DMSO浓度达40％，酶活力几乎完全丧失．说明DMSO对杂色鲍ALP有明显的失活作用．导致酶活力丧失50％的DMSO浓度为17％．在较低DMSO浓度（〈20％）的失活是可逆的反应过程．动力学研究表明，该酶的失活过程属于混合型．进一步测定游离酶（E）和酶底物络合物（ES）与DMSO的结合常数（K1和K1s），结果表明K1〈K1s即说明底物存在对酶被DMSO的失活作用有一定的保护作用．应用荧光发射光谱研究杂色鲍ALP经DMSO微扰后的分子构象变化情况，随着DMSO浓度增大，荧光强度逐渐增强．但发射峰未发生明显变化现象．说明酶分子中的生色基团残基的微环境发生了一定的变化．     

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.     

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-