两步活化法制备葡萄糖氧化酶电极的研究

采用多步活化法制备的聚乙烯醇膜 ,可在温和的条件下实现酶的固定化。用对甲基苯磺酰氯处理聚乙烯醇膜 ,与二乙胺反应引入氨基 ,再用戊二醛处理 ,最后用取得的活化膜载体可在温和条件下固定葡萄糖氧化酶。所得酶膜与碘离子选择性电极组装成的葡萄糖氧化酶电极 ,测定葡萄糖浓度时 ,线性响应范围为 1 6× 10 - 4～ 5 8× 10 - 3mol L。     

基于杂化材料和碳纳米管的葡萄糖氧化酶电极

介绍了一种基于有机-无机杂化材料和碳纳米管的葡萄糖氧化酶电极的制备方法.酶电极具有很好的灵敏度,响应时间只有3,s.碳纳米管的加入使酶电极的工作电位降低了0.3,V.酶电极可以在0.05,V以上对葡萄糖进行测量.在0.18 V时的线性范围为0～9.6,mol/L,检测限为2×10-7,mol/L.     

聚中性红和纳米金修饰玻碳电极的葡萄糖生物传感器

用循环伏安法在玻碳电极上电聚合一层稳定的中性红聚合物膜,研究了这层膜在0.1mol/L磷酸缓冲溶液(pH7.0)中的电化学性质.用Nafion将葡萄糖氧化酶(GOD)和纳米金固定于中性红修饰的玻碳电极表面,制成了新型葡萄糖生物传感器.实验发现,加入纳米金后提高了该传感器的灵敏度,对葡萄糖的线性响应范围为1.0×10-5～1.2×10-3mol/L,检测下限为5.0×10-6mol/L.该传感器制备方法简单、灵敏度高、稳定性好,并具有抗抗坏血酸、抗尿酸干扰的特点.     

基于多壁碳纳米管修饰的葡萄糖生物传感器

用循环伏安法在玻碳电极表面电沉积了一层稳定的甲苯胺蓝聚合物膜,以此作为电子传递介体,结合多壁碳纳米管、壳聚糖(CHIT)、葡萄糖氧化酶(GOD)混合包埋制备出一种新型葡萄糖生物传感器.实验结果显示,用此法制备的传感器对葡萄糖的线性响应范围为5.0×10-6~2.0×10-2mol/L,线性相关系数为0.9969,检测限为1×10-6,响应时间为3.2 s,并具有抗尿酸、抗坏血酸等干扰的特点.     

重金属离子对葡萄糖氧化酶电极抑制作用的研究

采用二氧化硅溶胶-凝胶固定化酶技术制备了葡萄糖氧化酶电极,优化了酶电极的工作条件。考察了酶电极的响应性能以及Hg^2＋,Fe^3＋等重金属离子对酶电极响应的抑制影响。实验结果表明在E=0．8V,pH=5．0,θ=25℃时,Hg^2＋,Fe^3＋的存在抑制了酶电极对葡萄糖的电流响应,且抑制电流的大小和重金属离子浓度在一定范围呈线性关系,线性范围分别是0～1．5μmot／L和0～60μmol／L。将被抑制的酶电极浸入EDTA溶液中10min后,酶电极可以恢复部分响应性能。     

氧化石墨烯-硫堇及纳米金修饰玻碳电极电流型葡萄糖生物传感器的研究

以玻碳电极为基底,在电极表面修饰一层氧化石墨烯-硫堇(GO -Th)薄膜,通过层层自组装方式,将纳米金和葡萄糖氧化酶(GOD)固定在玻碳电极表面,制得一种新型电流型葡萄糖生物传感器.在优化的实验条件下,该生物传感器对葡萄糖的线性响应范围为1.0×10-9 ～5.7×10-5 mol·L-1,检测下限为5.0×10-10...     

PVA固定化葡萄糖氧化酶电极的研制及应用——血清中葡萄糖含量的测定

本文报道了用聚乙烯醇(PVA)固定葡萄糖氧化酶(GOD)并制成酶电极,对膜的导电性能进行试验,在葡萄糖含量为2×10-5-1×10-3M的试验范围内,响应电流的变化与浓度成线性关系。用此电极以安培法测定血清中葡萄糖含量并与邻甲苯胺比色法、GOD-过氧化物酶比色法进行比较,结果较为满意。     

层层累积技术制备基于纳米碳管的葡萄糖生物传感器

以多壁纳米碳管(MWCNTs)为电子媒介体和酶的吸附载体,利用层层累积的自组装技术固定葡萄糖氧化酶(GOx)的多层(MWCNTs/GOx)n复合薄膜修饰电极,制备了一种新型葡萄糖生物传感器。结果表明:传感器对葡萄糖的响应电流值随着MWCNTs/GOx复合薄膜层数的不同而变化,当MWCNTs/GOx复合薄膜的层数为6时,响应电流值达到最大。(MWCNTs/GOx)6复合薄膜修饰的葡萄糖生物传感器对3×10-2mol/L葡萄糖的响应电流为1.63μA,响应时间仅为6.7 s。该生物传感器检测的线性范围为5×10-4~1.5×10-2mol/L,最低检测浓度可达0.9×10-4mol/L。     

萘酚绿为电子媒介体金纳米颗粒修饰的葡萄糖生物传感器

报道了一种制作新型电流型葡萄糖传感器的方法 .用金纳米颗粒吸附葡萄糖氧化酶 ,采用聚乙烯醇缩丁醛(PVB)为辅助固酶膜基质将其固定在铂金电极的表面 .在待测的葡萄糖溶液中加入萘酚绿作为电子媒介体 ,制成葡萄糖生物传感器 .酶吸附在纳米金表面上稳定且仍能保持其生物活性 ;而电子媒介体的存在 ,显著提高了传感器的响应灵敏度 .线形范围在 5 0× 10 -5～ 5 0× 10 -2 mol/L ,检测下限为 2 5× 10 -5mol/L(信噪比为 3) .用该生物传感器测定了人体血清中的葡萄糖 .尿酸、抗坏血酸等对测定无干扰 .     

钴卟啉和Nafion膜的葡萄糖电极的设计与优化

目的 :研制一种基于钴卟啉和Nafion的葡萄糖电极 .方法 :用序贯淘汰水平法对该电极膜组成进行优化 .结果 :其优化后电极的最佳膜组成为 :1.0mmol/L钴卟啉 [5 ,10 ,15 ,2 0 -tetrakis (4-methoxy -phenyl) - 2 1H ,2 3H -porphinecobalt](TMPPCo)溶液为 15 μL、10mg·mL- 1葡萄糖氧化酶(GOD)为 15 μL ,Nafion溶液为 6 0 μL .该电极用于测量葡萄糖时的线性范围为 :0～ 4mmol/L ,检测下限为 0 .4 μmol/L .结论 :该电极具有响应快速、灵敏、重现性好、寿命较长的特点 .     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.