培养条件对康宁木霉产酶的影响

通过对康宁木霉纤维素酶（C1酶和Cx酶）、酸性蛋白酶活力的比较,筛选出了康宁木霉产酶的最适培养条件.康宁木霉在m（麸皮）∶m（秸秆）=2∶8,氮源为w=1%的NH4NO3,含水量为65%,起始pH值为6.5的条件下培养72h,C1酶活力最高,为191.3U/g;在m（麸皮）∶m（秸秆）=6∶4,氮源为w=1%的（NH4）2SO4,含水量为65%,起始pH值为7.5的条件下培养48h,Cx酶活力最高,为2006.5U/g;在m（麸皮）∶m（秸秆）=8∶2,氮源为w=1%的（NH4）2CO3,含水量为65%,起始pH值为4.5的条件下培养96h,酸性蛋白酶活力最高,为1859.6U/g.     

黑曲霉产胞外核糖核酸酶的发酵条件的初步优化

研究了几种因素对黑曲霉突变株SA-13-20产胞外核糖核酸酶的影响.单次单因子优化,产酶水平提高了 170%,最高酶活达1 244 U/mL.研究发现磷酸盐抑制核糖核酸酶的生物合成,但促进菌体的生长,并且该菌产胞外核糖核酸酶不受外源核糖核酸的诱导.确定了最佳碳源,氮源及金属离子源分别为复合碳源(葡萄糖+玉米粉),NH4NO3及K2SO4,最佳菌龄为24 h.     

金针菇产木聚糖酶固态发酵条件优化和酶学性质研究

以豆秸粉为主要原料,通过单因素和正交试验确定金针菇(Flammulina velutipes)固态发酵生产木聚糖酶最佳培养条件,并对其粗酶的酶学性质进行了研究.结果表明,碳源为豆秸粉:玉米芯:麸皮=7:2:1,氮源为1.5%的黄豆粉,pH为5,接种量为干料的20%,装瓶量为6 g/100 mL三角瓶装,料水比为1:2.1,培养天数5 d,在此培养条件下得到的酶活力最高,产量可达52 768.91 U/g.粗酶液的最适反应温度为60℃,最适反应pH为6.酶的pH稳定性及热稳定性较好,80℃时相对酶活力仍保持在40.41%.     

产碱性纤维素酶真菌产酶条件的研究

研究了碱性纤维素酶生产菌株镰刀霉菌(Fusarum Sp.)的产酶条件.结果表明:该菌株产碱性纤维素酶的适宜碳源为1%麦杆粉+1%可溶性淀粉,最适氮源为O.2%的(NH_4)_2SO_4加0.1%的酵母粉,接种量为5%,培养时间为72 h,培养温度为46℃,培养基初始pH为8.0.在最适宜的条件下,培养液中内切葡聚糖酶活力可达到1.29 IU/mL,而天然纤维素酶活力和滤纸酶活力却很低.具有这种组分结构的碱性纤维素酶系统在棉织品的生物整理及洗涤剂工业中具有良好的应用前景.     

产单宁酶真菌的筛选及产酶条件

从铁冬青等4种植物的新鲜茎、叶组织中分离得到52株真菌,经平板透明圈法初筛得到18株产单宁酶菌株。初筛所得菌株经液体发酵,显示1株木霉属真菌(Trichoderma viride)(No.MYP07)酶活力最高,达0.248 μmol/(min·mL)。采用单因素结合正交实验,得到菌株MYP07的最佳发酵条件为：单宁100 g/L,蔗糖10 g/L,(NH4)2SO4 3 g/L,装液量为30 mL(250 mL锥形瓶),起始pH为5.0,温度30 ℃,转速140 r/min。在此条件下,菌株MY-P-07发酵48 h酶活力达到0392 μmol/(min·mL)。     

产果胶酶菌株的筛选鉴定及其产酶条件的研究

为筛选果胶高效降解菌株,结合HC比值(透明圈H与菌落直径C的比值)和果胶酶活力测定,从桔子园土壤和腐烂的水果等处筛选得到1株产果胶酶活力较强的菌株M3,结合菌株形态特征观察和ITS rDNA基因序列分析,确定该菌株为聚多曲霉(Aspergillus sydowii).经发酵产酶试验可知,该菌株的最适发酵产酶条件为培养温度30℃,初始pH4.5,接种量(体积分数)7%,培养时间4 d.在该条件下发酵,果胶酶活力可达42.01 U.mL-1.     

产气气杆菌产普鲁兰酶发酵培养基的优化

对一株产气气杆菌产普鲁兰酶的发酵培养基进行了优化,确定了该菌株的最适发酵培养基配方为(g/L):玉米淀粉 15,豆饼粉 10,CH3COONH4 8,K2HPO4·3H2O 0.5,MgSO4·7H2O 0.5,KCl 0.5,FeSO4·7H2O 0.05.采用该培养基在5 L 发酵罐水平发酵 55h,普鲁兰酶活力达到 54.64 U/mL.研究了不同铵盐形式对该菌株产普鲁兰酶的影响,结果发现:以CH3COONH4为无机氮源,该菌株产普鲁兰酶活力高,且该酶绝大部分能分泌至胞外.而以NH4Cl,NH4NO3及(NH4)2SO4为无机氮源,该菌产普鲁兰酶活力较低,且为胞内酶.     

长蛸胃肠道产蛋白酶菌的筛选及粗酶性质研究

通过透明圈法从长蛸胃肠道内筛选出4株产蛋白酶的菌株, L 1、L 2、L 3、L 5, 采用偶氮酪蛋白法测定粗酶液蛋白酶活力, 采用SDS PEAG活性电泳测定粗酶液中具有蛋白水解活性的蛋白酶的种类及分子量. 菌株L 2产蛋白酶比酶活最高, 达到4.80U/μg, 菌株L 1比酶活最低为3.31 U/μg. 菌株L 2粗酶液中含有4种酶活较高的蛋白酶, 分子量分别为105.2、86.9、69.3、37.8kD, 其他3株菌株的粗酶液中各蛋白酶分子量相近. 菌株L 1和L 2蛋白酶最佳反应温度为40℃, 最佳反应pH为8.0; L 3产蛋白酶的最佳反应温度为50℃, 最佳pH为7.0; 菌株L 5产蛋白酶在温度为60℃, pH为8.5时有最大酶活力.     

响应面法优化海洋细菌NTa产琼胶酶的发酵条件

利用Plackett-Burman试验、最陡爬坡试验和响应面法,对培养基组成、培养条件对Stenotrophomonas sp .NTa发酵产琼胶酶的影响进行分析并优化,研究该菌株发酵产酶的动态规律,并利用薄层色谱和MALDI-TO-MS进行酶解产物的鉴定。结果显示,在琼脂、酵母浸膏、CaCl2、MgSO4·7H2O、培养基的初始pH值、装液量、接种量几个因素中,酵母浸膏和培养基初始pH值对菌株NTa产琼胶酶具有显著影响,在含有1.03%酵母浸膏、初始pH=8.0的基础发酵培养基（NaCl、KNO3、MgSO4·7H2O、CaCl2、K2HPO4、FeSO4·7H2O、琼脂的质量浓度分别为50,5.0,5.0,0.2,0.1,0.02,2.0 g/L）中可获得最高的琼脂酶活力。菌株在28 ℃、180 r/min条件下发酵时,对数生长中后期快速合成琼胶酶。发酵48 h,琼胶酶活力高达2.688 U/mL。酶解72 h的产物分析结果显示,菌株NTa琼胶酶水解琼脂主要产生四糖。     

间歇出酶对里氏木霉产纤维素酶的影响

在分批补料的基础上,采用间歇出酶的方法,对里氏木霉产纤维素酶进行了研究。结果表明:分批补料过程中最佳的补料速度为5.5 g/(L·d),在此条件下产酶第8天滤纸酶活力和β-葡萄糖苷酶活力达到14.40 U/mL和1.59 U/mL。在分批补料的基础上进行间歇出酶,与对照相比,第4、6、8天出酶模式(模式1)时,总滤纸酶活力提高18.14%; 第4、7天出酶模式(模式2)时,总滤纸酶活力提高17.75%; 第5、8天出酶模式(模式3)时,总滤纸酶活力提高27.35%。研究表明,通过间歇出酶可以有效提高纤维素酶总滤纸酶的活力。     

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

<正>~~     

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.     

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