CS结构修饰及其与AA相互作用的空间位阻效应

为从分子水平探讨硫酸化多糖与小分子相互作用机理,本文采用氯磺酸-吡啶法(Wolfrom法)对硫酸软骨素(CS)进行结构修饰,制得了不同硫取代度的CS样品.应用光谱法研究了天青A(AA)与CS相互作用的吸收光谱,考察了硫取代度对CS抗凝血活性及AA与CS相互作用的影响,应用建立的酸性多糖与生物探针相互作用数学模型,测得AA与不同硫取代度的CS最大结合数分别为151,215,211和204,认为AA与CS相互作用具有空间位阻效应.     

透明质酸与天青A空间定向相互作用机理

采用光谱探针技术分析研究了天青A(AA)与透明质酸(HA)相互作用的吸收光谱,运用光谱法考察了AA/HA摩尔比、羟丙基-β-环糊精、乙醇、Triton X-100、pH以及NaCl对AA和HA反应体系的影响,测得HA对AA的最大结合数N=3.22×10~3,结合常数K=2.86×10~6,并且建立了AA与HA大分子空间定向相互作用的实验研究模型。实验结果表明,AA与HA相互作用产生的变色反应,不仅与AA和HA分子间的静电相互作用有关,而且还与HA大分子上结合态AA的密度有关,HA大分子上结合态AA分子间的疏水相互作用是形成550nm吸收峰以及产生变色反应的主要原因。     

枸杞多糖硫酸酯化修饰及其对Hela细胞的体外抑制作用

通过L_9(3)~4正交设计对氯磺酸-吡啶法制备枸杞多糖硫酸酯(SLBP)的修饰条件进行优选,最佳条件为V(氯磺酸):V(吡啶)=1:4,反应温度80 ℃,反应时间2 h.枸杞多糖硫酸酯中硫的质量分数可达17.23%,硫酸基取代度可达1.935.以紫外和红外光谱对产物加以表征,并用MTT法测定了对Hela细胞体外生长的抑制作用.在25～200 mg/L内,枸杞多糖(LBP)对人宫颈癌(Hela)细胞生长几乎没有抑制作用,而枸杞多糖硫酸酯对Hela细胞的抑制率可达31.71%.用本方法所制备的枸杞多糖硫酸酯具有较高的含硫量和硫酸基取代度,对Hela细胞生长具有明显的抑制作用,其抑制率与硫酸基取代度和用药剂量呈正相关.     

MA-AA-AM-SMAS四元共聚物的阻垢性能研究

以马来酸酐(MA)、丙烯酸(AA)、丙烯酰胺(AM)、甲代烯丙基磺酸钠(SMAS)等为原料,以过氧化氢为引发剂,通过水溶液聚合反应和膦酰化反应合成出含膦酰基、羧基和磺酸基的四元共聚物阻垢剂MA AA AMSMAS(PMAAS)。探讨了共聚物的投加量、钙离子质量浓度、溶液的pH值和温度等因素与共聚物阻垢率的关系,并用环境扫描电镜观测了碳酸钙与硫酸钙晶形的变化。经国标法测得,当pH=7,PMAAS用量为7mg/L时,其对CaCO3阻垢率可达99％,对CaSO4阻垢率达88.5％,与同类的产品相比,在碳酸钙垢和硫酸钙垢的阻垢性能上具有一定的优势。     

咪唑磺酸基多酸离子液体在酯化反应中的催化性能研究

合成了三种咪唑磺酸基多酸离子液体催化剂,并将其用于棕榈酸与甲醇的酯化反应研究.探讨了有机阳离子磺酸基上的酸性催化点位与多酸Brnsted酸性催化点位协同作用对酯化反应的影响.结果表明,[MIMPS]H2PW12O40(MIMPS=C7H13N2SO3)在醇酸物质的量比11∶1,催化剂用量0.06 mmol,反应时间8 h,反应温度65℃时转化率达98.3%,催化剂可循环使用6次.     

酸性离子液体催化合成食用香料丙酸香茅酯

研究了以含磺酸基离子液体1-(4-磺酸基)丁基-3-甲基吡嗪四氟硼酸盐([4-sulfbmpyrazine][BF4])为酸性催化剂,以香茅醇、丙酸酐为原料合成丙酸香茅酯,采用正交实验方案对合成条件进行了考察.实验结果表明,以酸性离子液体为催化剂合成丙酸香茅酯的较优条件为:n(香茅醇):n(丙酸酐):n(催化剂)为50∶100∶1,反应温度70℃,反应时间2 h,按优化条件进行验证实验,产品得率为95.3%.[4-sulfbmpyrazine][BF4]催化剂循环使用5次,催化活性基本不变.     

酶解龙须菜粗多糖硫酸基工艺优化

为探索重组芳香基硫酸酯酶水解龙须菜粗多糖的动态过程变化,同时为重组酶的应用提供基础数据,以p ET-28a为表达载体,在大肠杆菌(E.coli)中诱导表达获得能特异性水解硫酸酯的重组芳香基硫酸酯酶.并利用重组芳香基硫酸酯酶水解海藻龙须菜中的硫酸基团,以硫酸基含量和硫酸基脱除率为指标,利用单因素试验研究各因素对龙须菜粗多糖硫酸基水解过程的影响.试验确定了脱除龙须菜粗多糖硫酸基团的工艺条件,结果表明,重组芳香基硫酸酯酶水解龙须菜粗多糖的适宜工艺条件为:水解温度40℃,p H值7.0,初始底物5 g/L,加酶量108.14 U,振荡速率120 times/min,酶解反应2 h,在此工艺条件下脱除了78.4%的硫酸基团,凝胶强度提高2.1倍,凝固温度、融化温度分别为38.4℃和91.3℃.重组芳香基硫酸酯酶在酶解过程中水解龙须菜粗多糖中硫酸酯表现出较高的活力.     

亚甲基蓝介导抗坏血酸氧化动力学的研究

本文利用亚甲基蓝（MB）颜色可逆调控技术,研究了抗坏血酸（AA）的氧化动力学及MB的影响。蓝色MB与AA快速反应生成无色的还原态亚甲基蓝（LMB）,随后通入O2使LMB氧化回复始态的MB,并通过MB在664 nm的特征吸收峰监测AA的氧化。在饱和O2氛围中,AA的氧化呈现出零级反应动力学特征,其反应速率常数为0.193 mol L1 s1;MB不仅能作为检测AA的光谱探针,而且能促进AA的氧化,使AA的氧化反应活化能降低了35.5%,速率常数增大了1.5倍。此外,该方法应用于片剂中AA的含量测定和氧化评价,显示了2.1%的相对标准偏差,具有成本低、灵敏度高、重现性好的特点。     

化学酶法对硫酸软骨素类多糖的定量分析

硫酸软骨素(chondroitin sulfate, CS)类多糖是一类具有多种临床治疗作用的糖胺聚糖。在硫酸软骨素裂解酶作用下，软骨素中葡糖醛酸和N-乙酰半乳糖胺之间的糖苷键发生断裂，可生成不饱和二糖。微生物发酵生产软骨素过程中，多糖定量往往需经过多次纯化以及使用昂贵的仪器进行检测，过程繁琐。文章研究偶联了专一性的酶解法与蒽酮-硫酸法，快速测定复杂培养液中的软骨素类多糖质量浓度。该方法通过超滤去除单糖等小分子杂质后，将多糖用专一性硫酸软骨素裂解酶分解为寡糖，再通过超滤去除大分子杂质，得到的寡糖过滤液使用蒽酮-硫酸法快速测定多糖质量浓度。该多糖定量方法可以选择不同特异性的裂解酶，适用于复杂培养液中其他多糖的快速定量分析。     

膦基磺酸共聚物阻垢分散剂的研制

以水为溶剂,次亚磷酸钠-过硫酸钠为引发剂,丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体合成了集膦酸基、羧酸基和磺酸基于一体的水溶性共聚物.讨论了单体配比、NaH2PO2用量、引发剂用量、反应温度、反应时间等因素对共聚物性能的影响规律.研究结果表明:该共聚物具有较好的阻碳酸钙垢、磷酸钙垢和稳定锌盐沉积的能力.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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.     

A computer generator for randomly layered structures

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

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to