福寿螺β-葡萄糖苷酶催化功能基团

应用化学修饰法研究福寿螺β－葡萄糖苷酶活性功能基团的性质．用５，５′－二硫代双（２－硝基苯甲酸）和对－氯汞苯甲酸为修饰剂修饰酶分子中的巯基，酶活力基本不受影响，说明该酶不是“巯基酶”．用Ｎ－溴代琥珀酰亚胺在ｐＨ６．０下修饰酶后，可使酶活力完全丧失，被修饰后的酶分子在２７８ｎｍ处的紫外吸收峰逐渐下降至完全消失，３３８ｎｍ处的荧光发射峰也逐渐下降至完全淬灭，说明色氨酸残基是酶活性必需基团之一．用碳二亚胺、溴代乙酸或甲醛修饰酶，可以使酶活力完全丧失，说明羧基、组氨酸的咪唑基及赖氨酸的氨基也与酶活性有密切的关系．用乙酰丙酮、苯甲磺酰氟修饰酶，酶活力不受影响，表明精氨酸残基和羟基与酶活性无关．     

用固定化酶管流动注射测定谷氨酸

用多孔玻璃珠固定自制的谷氨酸氧化酶（GO）制成GO固定化酶管，并结合流动注射系统测定谷氨酸（Glu)的含量，测定的线性范围在0．2－3．0mol/m3，精密度（c.v.)为0．75％，测定速率每小时60个样品，该酶管使用寿命为40d，在一定的条件下，保存稳定期达120天，当测定的Glu浓度低于3mol/m3时，pH在6．5－7．5，温度在20－30度，磷酸盐浓度在0．05－0．25mol/L范围内变化时，对Glu含量的测定几乎无影响，用醋酸纤维膜修饰的铂电极测定H2O2选择性好，该方法与试剂盒法同时测定不同发酵时间发酵液中Glu的含量，两者结果一致。     

米曲氨基酰化酶的纯化及固定化酶法拆分D,L-丙氨酸

利用硫酸铵分级与双水相萃取结合的方法从米曲霉中提取米曲氨基酰化酶,并将其固定在ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－２５上,用于拆分Ｄ,Ｌ－丙氨酸,并对该酶及固定化酶的酶学性质进行研究     

MNP对氨基酰化酶的不可逆抑制作用的研究

用有机汞试剂ＭＮＰ对氨基酰化酶进行了修饰，在ＭＮＰ存在的情况下，连续监测了氨基酰化酶催化底物的反应过程，发现ＭＮＰ对氨基酰化酶的抑制作用为构象变化型。     

壳聚糖修饰L-天门冬酰胺酶对酶活及抗原的影响

采用水溶性壳聚糖对L－天门冬酶胺酶进行化学修饰，修饰后的酶活回收率高达705，修饰酶的比活为每毫克蛋白质121.79U，pH值为7.4，更接近于人体血浆pH值(7.2-7.4），对底物的亲和力有所提高，稳定性增加，抗原性仅为自然酶的1／3，增加了临床使用的安全性。     

青霉素酰化酶研究——Ⅱ.酶的修饰和修饰酶的性质

本文介绍用β-硫酸酯乙砜基苯胺(SESA)活化右旋糖酐T2000以修饰大肠杆菌5852青霉素酰化酶。活化时500mg右旋糖酐需SESA 20mg。制备对氨基苯磺酰乙基葡聚糖(ABSE)-右旋糖酐的反应温度为80℃,与500mg活化右旋糖酐偶联的酰化酶酶量为100u,修饰率达88.3%。用琼脂糖(Sepharose 4B)或交联葡聚糖(Sephadex G150)柱层析分离得高分子量的修饰酶。修饰酶对热和pH的稳定性均优于自由酶,最适温度提高,但最适pH和高浓度青霉素G底物抑制现象没有改变。     

共介修饰的辣根过氧化物酶及其在酶传感器中的应用

将介体对甲酰苯基二茂铁与辣根过氧化物酶共价结合,然后同单体毗咯一起电聚合到铂电极上,再通过戊二醛将葡萄糖氧化酶交联固定在电上,制成共价修饰的ＨＲＰ／ＧＯＤ介体酶传感器。共价修饰的酶传感器影响电流增大,底物测试范围０－４０ｍｍｏｌ／Ｌ,电极稳定性增强。     

青霉素G酰化酶在磁性复合载体上的固定化及其酶学性质

利用凝胶-溶胶方法对磁性Fe3O4微粒表面进行功能化修饰,制备了表面含氨丙基的磁性复合载体,并通过戊二醛交联制备固定化青霉素G酰化酶(PGA).结果表明,在37℃时,固定化酶水解青霉素G钾盐,制备6-氨基青霉烷酸的表观活性为1 886 IU/g,表观米氏常数K'm＝140 mmol/L,最大反应速度Vmax＝0.45 ...     

基于聚氨基吡啶膜固定纳米金/硫堇/纳米金的过氧化氢生物传感器

研究了在铂丝电极上电聚合一层带正电的2氨基吡啶膜,然后再利用层层自组装技术固定纳米金、电子媒介体硫堇及辣根过氧化氢酶,从而制备了由辣根过氧化氢酶/纳米金/硫堇/纳米金/聚2氨基吡啶膜修饰的酶生物传感器.实验中探讨了聚合层数、温度、pH值等对电极响应的影响.结果表明该传感器在H2O2浓度6·0×10-7~1·3×10-3mol/L范围内呈线性响应,检出限为2·1×10-7mol/L.此外,该传感器具有好的稳定性和选择性,能有效排除抗坏血酸、柠檬酸、葡萄糖等常见物质的干扰.     

锯缘青蟹碱性磷酸酶活性功能团研究

应用化学修饰法结合酶的紫外吸收光谱及荧光发射光谱的变化研究锯缘青蟹碱性磷酸酶的功能基团性质，结果表明：色氨酸的吲哚基团、赖氨酸的ε－氨基、组氨酸咪唑基及精氨酸残基是酶活性必需基团，而巯基与酶活性无关．     

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.     

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.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.