发酵液中L-苹果酸和残糖的扫描光度法测定

通过对纸层析斑点面积法、DNS法和紫外—可见扫描光度法的比较研究,建立后一种可同时测定发酵液中L-苹果酸和残糖含量的新方法,在本测定条件下,扫描峰值(或OD)与L-苹果酸浓度在40～200μg/ml、和残糖浓度在150～400μg/ml内均呈线性关系,其标准误差分别为0.53和0.64;变异系数分别为4.23％和0.24％;平均回收率分别为93.33％和91.42％。     

连翘中具有药物活性成分内生菌的筛选及其拮抗特性的研究

采用组织分离法从连翘枝条中筛选出13株内生菌,其中有7株内生真菌,6株内生细菌。分别以金黄色葡萄球菌、大肠杆菌为指示菌株,采用平板对峙法对分离出的13株内生菌的抗菌活性进行筛选。结果表明：13株菌种中有10个菌株对1种供试菌具有抑菌活性。其中L-07-01、L-07-09、L-07-12、L-07-13的拮抗效果明显,L-07-09对金黄色葡萄球菌具有较强的抑菌效果,测量其抑菌圈直径为10 mm。L-07-12对大肠杆菌具有较强抑菌效果,测量其抑菌圈直径为10 mm。对拮抗效果较强的菌株进行液体发酵培养后采用双层打孔法,测定其抑菌效果后证明L-07-13对金黄色葡萄球菌有极强的抑制效果。对拮抗后的指示菌进一步镜检后,发现菌体有明显的溶菌、空洞、畸形等现象。连翘内生菌可以产生丰富的具有药物活性的次生代谢产物,可作为新型药物的筛选源。     

L-精氨酸产生菌的离子束诱变育种

采用N离子束对谷氨酸棒杆菌进行诱变处理,筛选磺胺胍抗性突变菌株,将突变菌株进行摇瓶发酵实验,选育出一株L-精氨酸产量较高和产酸性能比较稳定的突变菌株。该菌株L-精氨酸产量比出发菌株提高了24.8%。     

L-乳酸高产菌选育及其发酵条件的优化

从自然界分离筛选到产酸菌66株,经发酵和遗传稳定性测试后,保留L-乳酸产量高的菌株LC14作为诱变出发株;然后改造MRS培养基,以乙酸钠和乙酸为碳源,对突变株定向筛选,再经发酵测试复筛,最优突变株的L-乳酸产量达57.9 g/L,为出发株的2.2倍.又根据不同温度对细胞生长代谢的差异,建立了变温发酵过程:20 h前控温...     

高产1,3-丙二醇的海洋克雷伯氏菌株的分离鉴定（英文）

从海洋环境中分离并鉴定用于发酵生产1,3-丙二醇的海洋微生物菌株.1,3-丙二醇是一种重要的工业原料,主要用于生产新型聚酯材料——聚对苯二甲酸丙二醇脂.通过富集与选择培养、摇瓶发酵测试,筛选得到一株高产1,3-丙二醇菌株;通过API20E试剂条反应、16S r RNA基因序列比对分析、电镜形态观察及相关基因簇分析,鉴定命名该菌株为Klebsiella pneumonia HSL4.进一步分析表明该菌株具有耐盐、耐有机酸的特征.补料发酵实验表明,该菌株合成1,3-丙二醇浓度、生产强度、转化率分别达到80.08 g L-1,2.22 g L-1 h-1和0.53 mol mol-1.     

液体发酵高产纳豆激酶菌株的复合诱变选育

从市售豆豉和保藏的固体发酵产纳豆激酶(NK)高活性的菌株中,筛选出5株诱变育种出发菌株.经紫外-亚硝基胍-Co60复合诱变后,获得5株液体发酵产NK高活性的菌株LJJ-1-13-12-4、PXDBJ-13-9-7-18、DNS-17-3-15-7、CBL-2-7-10-6和L-5-8-15,其产NK活性,分别为1 846.15、1 956.48、2 184.32、1 865.38和2 095.23 U/mL,分别是诱变前出发菌株的1.62、1.81、1.98、1.61和1.62倍.高产纳豆激酶菌株的选育为纳豆激酶液体发酵的进一步工业化奠定了良好的基础.     

产木聚糖酶海洋微生物的筛选与诱变育种

以自制木聚糖为初筛培养基的唯一碳源,从多个海洋来源样品中一共筛到60株有透明圈且形态各异的菌株,摇瓶发酵结果显示,38株具有产木聚糖酶能力,其中B659菌株产酶能力最高,酶活力为525.3 U·m L-1.结合B659菌株的形态特征和16S r DNA序列分析鉴定该菌株属于Bacillus属.对B659菌株进行紫外诱变,筛选得到酶活提高13.9%且稳定遗传的突变菌株G3-17;对G3-17菌株进一步进行微波诱变得到酶活较G3-17菌株高出11.6%且稳定遗传的突变菌株W1-40.对B659菌株和W1-40突变菌株进行发酵试验,72 h时W1-40菌株的酶活力达到645.2 U·m L-1,比B659菌株(517.9 U·m L-1)提高24.6%.     

酶电极法检测苹果酸-乳酸发酵过程中乳酸变化

以固定化L-乳酸氧化酶（1．1．1．27）与H2O2电极构成乳酸酶电极生物传感器,研究了乳酸酶电极分析法的各种分析条件及参数,并与药典标准总酸测定法对比测定了葡萄酒苹果酸-乳酸发酵溶液中L-乳酸的含量。结果表明供试溶液中L-乳酸含量约占总酸量的10％～20％。采用酶电极法测定葡萄酒苹果酸-乳酸发酵溶液中的L-乳酸含量具有专一性高、成本低、分析速度快等优点。     

一株高产乳酸鼠李糖乳杆菌的选育

采用紫外线和Co60照射联合诱变鼠李糖乳杆菌(Lactobacillus rhamnosus)JCM1553菌株,选育得到1株L-乳酸高产突变株SCT-10-10-60.经77代传代培养证实该菌株L-乳酸发酵遗传稳定.在37℃,200rpm下,该菌株摇瓶发酵葡萄糖60h的发酵液乳酸浓度达到最大,为195.67g/L,发酵糖酸转化率达到95.33％,比出发菌株最大乳酸产量、发酵速率和糖酸转化率分别提高了16.24％、50.13％和17.81％.相同条件下该菌株发酵木薯淀粉84h的乳酸浓度达到最大值,为203.33g/L,糖酸转化率达到78.85％,比出发菌株最大乳酸产量和发酵速率均提高了29.49％,糖酸转化率则提高24.53％.该菌株发酵产物的L-乳酸含量高达96.75％,与出发菌株(96.97％)无统计学显著差异(P＞0.05).该高产菌株乳酸发酵性能提高的主要原因是菌体增长速率加快.其L-乳酸发酵性能显著优于现有的生产菌株,具有较高的潜在工业价值.     

发酵液中L-丝氨酸的简易测定方法的研究

利用“纸层析-分光光度法”对发酵液中的L-丝氨酸进行了定量测定,确定了L-丝氨酸定量测定条件.实验表明,该法对测定L-丝氨酸含量具有较高的准确度和精密度.而且该法操作简单、易于掌握,非常适合在L-丝氨酸生产中应用.     

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