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1.
采用华东理工大学国家化工程技术研究中心(上海)生产的全自动多参数FUS-50L(A)生物反应器,在不同的控制方式下,研究了溶解氧水平对菌体代谢活力及鸟苷发酵水平的影响。结果表明:发酵过程中,用调节转速的方式控制发酵液中溶氧水平的效果比用空气流量好;发酵液中氧中溶氧水平控制在10%-20%时鸟苷积累量高,发酵液中溶氧水平低(5%)和高(30%)均不利于发酵液中的鸟苷积累。  相似文献   

2.
基于DPS数据处理的鸟苷分批发酵动力学模型   总被引:1,自引:0,他引:1  
以枯草芽孢杆菌TA208(Ade^-+MSO^r+8-AG^r)为供试菌株,对鸟苷分批发酵动力学模型进行研究。利用DPS数据处理软件模型参数求解的原理,建立合理的分批发酵动力学模型。经实验验证,模型的拟合结果和实验值能够较好吻合,说明该动力学模型能正确描述鸟苷的分批发酵过程。  相似文献   

3.
范立峰 《海峡科学》2007,(12):47-47
目的:探讨贝复舒和无环鸟苷联合治疗单疱病毒性角膜炎的临床应用。方法:21例32眼,患者随机分为二组,治疗组应用0.1%无环鸟苷和贝复舒眼液.对照组仅给予0.1%无环鸟苷,每日6-8次滴眼。结果:治疗组16眼,有效率93%,平均治疗时间18天.对照组16眼.有效率75%,平均治疗时间37天:两组有效率与治疗时间比较差异有统计学意义(P〈0.01)。结论:贝复舒和无环鸟苷联合治疗单疱病毒性角膜炎有协同作用。可明显缩短病程。提高治愈率。  相似文献   

4.
克氏原螯虾Procambarus clarkii能够识别水中信息素进行求偶,明确其信息素的有效组分能为克氏原螯虾绿色治理提供理论依据。本文采用Y型水迷宫测试鸟苷-5′-单磷酸二钠、鸟苷-5′-二磷酸二钠、鸟苷-5′-三磷酸二钠、N-乙酰-L-亮氨酸、己酸孕酮、乙炔雌二醇、胆红素和4-巯基尿苷等8种化合物对克氏原螯虾选择行为的影响,筛选具有引诱作用的乙炔雌二醇和己酸孕酮进行浓度测试。结果表明:雄性克氏原螯虾对4-巯基尿苷、胆红素、N-乙酰-L-亮氨酸、鸟苷-5′-三磷酸二钠、鸟苷-5′-二磷酸二钠、鸟苷-5′-单磷酸二钠的选择反应率接近50%,选择系数在±0.15之间,引诱效果不显著(P>0.05);对乙炔雌二醇和己酸孕酮选择反应率高,分别为64.10%、63.24%,选择系数为0.28、0.26,且表现出性别上的显著差异。对雄虾,乙炔雌二醇的最低有效引诱阈值是10μmol/L,己酸孕酮的最低有效引诱阈值是100μmol/L,而雌虾对这2种化合物不敏感。因此,己酸孕酮和乙炔雌二醇对雄性克氏原螯虾具有明显的引诱效果,却对雌鳌虾无明显反应,表明己酸孕酮和乙炔雌二醇是克氏原螯虾性信息素的...  相似文献   

5.
利用途径分析的方法对枯草芽孢杆菌发酵生产鸟苷的途径进行分析,确定了3个基本反应模型,计算出最优途径的理论产量和通量分布.三个基本模型的理论摩尔产量分别为0.625、0.75、0.667.通过调整化学调节因子NH4^ 和Mg^2 ,可以使鸟苷产量由14.4g/L提高到19.2g/L。  相似文献   

6.
用紫外吸收光谱法和荧光光谱法研究了七元瓜环对鸟苷的分子包结作用,以及体系pH值对主客体相互作用的影响.结果表明,瓜环与鸟苷相互作用受体系pH值的影响,在体系pH约为3的条件下,七元瓜环对鸟苷有较大的包结能力,并且形成了1:1的包结配合物.  相似文献   

7.
在组织培养系统中,甘草酸单铵和无环鸟苷伍用产生一定的相加抗Ⅰ型单纯疱疹病毒作用.两药伍用的最低剂量分别为1.0mg/mL和0.125μg/mL.在伍用浓度下,没有任何干扰和抵消作用,同时也未发现对细胞的毒性作用.两药合用可能为无环鸟苷的用药开辟新途径.  相似文献   

8.
探讨了两种性质相反的聚合物支载的高碘酸根离子和硼氢根离子,以鸟苷为底物,一锅法合成鸟苷三醇,此方法具的操作简便,反应条件温和合成路线缩短, 离中间体,产率较高等特点。  相似文献   

9.
运用BP神经网络对鸟苷发酵培养基组成进行建模以及鸟苷产量预测,在此基础上利用遗传算法对鸟苷发酵培养基组成进行全局性寻优,得到最佳鸟苷发酵培养基组成:葡萄糖120 g·L-1,豆饼水解液50 g·L-1,酵母粉16 g·L-1,(NH4)2SO415 g·L-1,味精10 g·L-1,CaCO320 g·L-1(分消),CaCl22 g·L-1,硫酸镁3 g·L-1,生物素0.9 mg·L-1,硫酸锰4 mg·L-1,磷酸二氢钾4 g·L-1。结果表明,BP神经网络与遗传算法耦联法能够有效地优化发酵培养基配比。  相似文献   

10.
初步选择了HD-8和HZ014两种树脂进行鸟苷和肌苷分离测定实验,通过模糊聚类对实验结果分析得到分离测定操作条件的较优区域:再选择适当的条件进行静态吸附实验,从3种树脂HD-8、HZ014和732中最终确定采用树脂HD-8.通过模糊聚类产生的较优区域中的不同务件下实验结果的比较,最后确定最佳分离条件为:采用树脂HD-8,树脂床高度为4cm.流速为1mL/min,前120mL采用0.05mol/L盐酸洗脱收集肌苷,120mL后至240mL采用0.74moL/L pH5.0醋酸钠缓冲液洗脱收集鸟苷。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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。  相似文献   

15.
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  相似文献   

16.
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  相似文献   

17.
18.
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.  相似文献   

19.
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).  相似文献   

20.
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.  相似文献   

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