韧化处理淀粉对直链淀粉溶出过程的研究

为研究韧化处理过程中直链淀粉溶出规律,以玉米淀粉为原料,在单因素实验的基础上,采用响应曲面法对韧化处理时温度和时间进行优化.建立了两个因素与直链淀粉溶出率之间的相关性,得到直链淀粉溶出过程的回归方程,经验证可以用得到的模型预测韧化处理时玉米淀粉的直链淀粉溶出过程.     

分离方法对玉米淀粉分离组分结构特性的影响

对分离方法影响玉米直链淀粉、中间成分和支链淀粉的结构特性进行了研究.结果表明:分离方法对玉米直链淀粉、中间成分和支链淀粉的微观结构、碘亲和力、蓝值、平均聚合度(DP)、平均链长(CL)和摩尔平均链数(NC)影响较大,而方法三对它们与碘形成复合物的λmax有较大影响;与玉米原淀粉相比,分离方法使玉米直链淀粉、中间成分和支链淀粉的结晶相由A型转变为C型,同时使它们的结晶度下降.     

导入反义蜡质基因降低两系不育系稻米直链淀粉含量

为了提高两系不育系261S水稻的选配范围，研究利用根癌农杆菌介导法将蜡质基因反义片段导入261S未成熟种子形成的愈伤组织，经抗性筛选及PCR检测获得46棵T0代转基因植株．采用GUS染色追踪分析获得转反义蜡质基因纯合的T2代转基因植株．10个转基因植株糙米经直链淀粉含量分析显示：未转基因261S对照水稻糙米直链淀粉平均含量为18．54％，大部分转基因后代糙米直链淀粉含量有不同程度的降低，降低程度最大的转基因后代糙米直链淀粉平均含量为13．55％，比对照降低26．91％．开展本研究可为两系杂交稻优质育种奠定基础．     

桄榔淀粉的级分及其凝胶色谱分析

用正丁醇结晶法分离得到桄榔(Arenga pinnota)淀粉的直链淀粉与支链淀粉后,采用HPLC排阻凝胶色谱法测定桄榔直链淀粉与支链淀粉的纯度和相对分子量。结果得到,桄榔直链淀粉的纯度为100％,平均保留时间为6．48min,支链淀粉的纯度为100％,平均保留时间为4．12min;直链淀粉的相对分子量为45000,支链淀粉的相对分子量为5600000。     

糊化和凝沉玉米淀粉的消化性能

以4种不同直链淀粉含量的玉米淀粉为研究对象,利用Brabender黏度仪与差示扫描量热仪(DSC)对淀粉糊性质与热力学性质进行了表征;考察了糊化及糊化后4℃条件下保藏24h两种处理方式对玉米淀粉消化性能的影响,分析了直链淀粉含量与玉米淀粉消化性能的关系.结果表明:直链淀粉含量对淀粉的峰值黏度、消减值、DSC糊化温度影响显著;在in-vitro消化模型中,4种玉米淀粉经两种方式处理后产生的消化产物总量以及消化速度均随着直链淀粉含量的升高而降低;4℃条件下保藏24h处理后,凝沉淀粉消化产物总量与消化速度均低于糊化淀粉,且降低程度与直链淀粉含量有关.     

高直链淀粉玉米的研究现状与发展前景

本文主要从高直链淀粉玉米的育种，使用，生产方面来说明其研究现状，并提出了我国现阶段在高直链淀粉玉米的研究中所面临的严峻挑战及在我国的发展前景。     

醇类化合物对直链淀粉增塑效果的影响

为预测醇类增塑剂所含碳原子数以及羟基数对淀粉增塑效果的影响,采用分子动力学模拟法在COM-PASS力场下模拟计算不同醇类小分子对直链淀粉增塑后玻璃化温度的影响,并测定不同醇类小分子对直链淀粉增塑后旋转扭矩、氢键削弱作用和力常数的变化。通过比较不同醇类化合物对直链淀粉增塑前后的玻璃化温度、旋转扭矩、氢键削弱作用和力常数变化预测醇类化合物增塑效果。结果表明,三类醇类化合物对直链淀粉的增塑效果依次为：乙二醇〉丙三醇〉1,2-丙二醇。由此可推断,当醇类增塑剂含羟基数相同时,碳链越短,对直链淀粉的增塑效果就越好;当所含的碳原子数相同时,醇类增塑剂中所含的羟基数越多,对直链淀粉的增塑效果就越好。     

用简单快速方法测定河南一些稻谷样品直链淀粉的含量

<正> 一、前言稻米是我国人民的主要粮食之一。淀粉是稻米的主要营养成份。它是由结构和性质不同的两种成份——直链淀粉和支链淀粉所组成。这二种淀粉的含量与比例。与稻米的食用和工艺的品质有着密切关系;直链淀粉含量对米饭的食味、光泽、凝聚性和柔软性都有较大的影响。1971年国际水稻研究所测定许多地区稻米直链淀粉含量与适口性的报告中指出:东南亚最受欢迎的稻米品种、直链淀粉含量都占总淀     

杂交稻籽粒直链淀粉含量与解剖结构关系研究

以几个杂交稻组合为材料,测定其单粒或半粒米的直链淀粉含量,并用扫描电镜观察其胚乳结构,结果表明：在籽粒灌浆盛期之初,杂交稻籽粒平均直链淀粉含量较低,粒间差异较大,至灌浆盛期之末,其直链淀粉含量明显增高,粒间差异减小;杂交稻籽粒直链淀粉含量性状的分离与胚乳结构变异没有明显确的关系,胚乳结构可能不存在遗传传分离。     

藕淀粉特性的研究

就藕根茎淀粉的分子结构形状及其理化特性进行了研究。结果表明碘亲和力测定的藕直链淀粉含量为15．9％,蓝色值法为17．4％,开始凝胶化温度为58．5℃,淀粉颗粒与木薯淀粉、大米淀粉等有类似的性质,可作为此类淀粉制品的替代品。     

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.     

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.     

A computer generator for randomly layered structures

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

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。     

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.