一株Kefir源乳酸菌MA2的鉴定及对大鼠肠道菌群的影响

对从西藏Kefir粒中分离出来的乳酸菌MA2进行了形态学、生理生化和16SrDNA分子生物学鉴定,确定其为植物乳杆菌．酸和胆盐耐受性实验显示,植物乳杆菌MA2在pH2．0、胆盐浓度为0．3％的情况下具有较好的耐受能力．动物实验证明,植物乳杆菌MA2显著促进了双歧杆菌和乳酸菌的生长,调节了肠道菌群的平衡,是一株潜在的、具有实际应用价值的益生菌．     

甘露低聚糖

当今市场上最热门的功能食品配料——低聚糖,是甘露糖与葡萄糖相连的直链低聚物,主要由二糖至六糖组成,具有功能食品的优良特点:1.非吸收性:甘露低聚精是由β—1.4糖苷键相连的低聚糖,人体不能消化吸收,不会引起血糖升高,可有效地到达肠道下部.2.对有益菌的增殖性:经动物及人体服用试验表明,甘露低聚糖可使体内的双歧杆菌显著增殖,服用一周后,粪便中的双歧杆菌增加 50～100倍,同时抑制有害菌增殖,而且动物增重明显.体外试验也表明,甘露低聚糖可被多种双歧杆菌(如长双歧杆菌,婴儿双歧杆菌、两双歧杆菌等)及链球     

双歧杆菌生长特性及发酵乳的研究

采用液体牛乳培养基培养法,测定了双歧杆菌的生长,产酸和ＰＨ变化,其最佳发酵条件为：接种量５％,培养温度３９℃、庶糖添加量５％。此外,对利用双歧杆菌制做双歧杆菌酸奶进行了研究,通过实验确定了采用两次接种发酵法生产凝固型酸奶的工艺参数,产品风味与传统酸奶一奶,双歧杆菌活菌数达到７．０＊１０＾９个／ｍｌ左右。     

不同益生菌对蛋鸭产蛋性能及血液生化指标的影响

采用乳酸杆菌、双歧杆菌、枯草芽胞杆菌、光合菌和复合菌（乳酸杆菌＋双歧杆菌）五种益生菌饲喂蛋鸭试验,测定蛋鸭的产蛋量及蛋鸭的血液生化指标．试验结果表明,添加了益生菌的各试验组,其产蛋率和总蛋重比对照组均有显著提高,差异显著（P〈0．05）,但各试验组之间的差异不显著（P〉0．05）．各试验组的生长激素（GH）、胰岛素（IGF）、三碘甲状腺原氨酸（B）及甲状腺素（T4）的含量均显著高于对照组（P〈0．05）．对照组尿酸（UA）和尿素氮（BUN）的含量极显著高于其他各试验组（P〈0．01）．但各试验组之间的以上各种血液生化指标准均无显著性差异（P〉0．05）．     

铀矿石成分对铀的细菌浸出影响研究

对几种含不同成分的铀矿石进行了铀的氧化亚铁硫杆菌柱浸实验和耐性实验研究．柱浸实验结果表明，与硫酸浸出相比，细菌浸出可降低酸耗5％-20％．耐性实验结果表明，氧化亚铁硫杆菌经过驯化培养，能在铀质量浓度近2．0g／L的环境中生存并可氧化Fe^2＋，耐F^-可从驯化培养前质量浓度0．28g／L提高到0．83g／L．     

饲喂双歧杆菌制剂对锥鸡肠道正常菌群及对雏鸡和肉仔兔增重？…

对刚出孵的雏鸡以氟啤酸作对照饲喂双歧杆菌制剂，结果显示：服用双歧杆菌制剂锥鸡的肠道内的双歧杆菌数与氟哌酸组差异显著（Ｐ〈０．０５）；在肠杆菌数差异不显著（Ｐ〉０．０５）；均未检出沙门氏杆菌。在雏鸡增重效果方面，双歧菌制剂与氟哌酸对照组相比差异显著（Ｐ〈０．０５），且双歧杆菌与氟哌酸一样对锥鸡下痢具有良好的预防效果。同时用双歧杆制剂饲喂肉仔兔进行增重试验，结果试验组与对照组增重差异显著（Ｐ〈０．０５     

猪源双歧杆菌筛选及生物特性参数测定

采用双歧杆菌选择性培养基，从健康猪肠道和粪便中共分离到９０株细菌，根据微生态学关键指标，筛选出１０株双歧杆菌，这些菌株能够耐受０．８％－１．０％的胆盐，在ＰＨ３．５ＢＳ肉汤中３７℃下保浊ｈ存活率在４０％以上，代谢产物对４种常见致病菌均有不同程度的抑制作用，双歧杆菌与上述４种致病菌在ＢＳ液体培养基中混合培养到３６ｈ，能够彻底清除病菌，３株双歧杆菌对小猪肠道上细胞有良好的粘附作用。     

两种海洋寡糖对双歧杆菌体外生长作用的影响

壳寡糖、褐藻寡糖是具有独特生理活性的功能性海洋寡糖。以壳寡糖、褐藻寡糖分别代替葡萄糖作为培养基的碳源,观察双歧杆菌在体外生长的情况,比较分析2种寡糖对双歧杆菌生长的作用效果。结果表明：2种寡糖可使双歧杆菌大量增殖,对双歧杆菌体外生长有显著的促生长作用,且作用效果明显优于葡萄糖。褐藻寡糖在2.5~1.25 g.L-1范围内,作用变化幅度较小;而壳寡糖则表现为高浓度优于低浓度。培养基中添加壳寡糖的最佳质量浓度为1.25 g.L-1,添加褐藻寡糖的最佳质量浓度为0.625 g.L-1。     

可溶性甲壳胺的制备及促双歧杆菌生长的研究

探讨采用不同方法制备的可溶性甲壳胺对双歧杆菌生长的不同作用．用盐酸水解法和氯磺酸磺化法分别制得可溶性甲壳胺,加入双歧杆菌的培养液,定时检测双歧杆菌数目的变化．结果表明,通过氯磺酸磺化法得到的可溶性甲壳胺有明显促双歧杆菌的作用,且比盐酸水解法得到的可溶性甲壳胺更有效．     

双歧杆菌对抗菌素的敏感性与抵抗性

对 10种抗菌素进行双歧杆菌的敏感性试验 ,探讨VitC、VitB1、VitB6及异麦芽寡糖对双歧杆菌抵抗抗菌素的敏感作用 .结果表明 ,双歧杆菌对 β -内酰胺类 (MIC :青霉素 0 .1177～ 0 .310 5 μg /mL ,先锋VI号 0 .2 95 9～ 0 .885 3μg /mL)、大环内酯类 (MIC :红霉素 0 .0 85～ 0 .1137μg /mL ,制霉菌素 0 .90 46～ 8.0 2 9μg /mL ,乙酰螺旋霉素 1.2 9～ 2 .94μg /mL)以及四环类的四环素 (MIC :0 .2 46 3～ 0 .4118μg /mL)很敏感 ;对四环类的土霉素(MIC :15 .7～ 2 9.4μg/mL)较敏感 ;对氨基糖苷类 (MIC :链霉素 6 5 .9～ 190 μg /mL、庆大霉素 490～ 941μg /mL、卡那霉素 16 5～ 2 15 μg /mL)的作用不敏感 .而 3种维生素和异麦芽寡糖均具有提高双歧杆菌对抗菌素的耐药性     

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…     

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.     

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.