光合菌群利用丁酸产氢的初步研究

对影响光合茵群利用丁酸产氢的主要因子:初始细胞浓度、温度、初始pH值、光照强度和丁酸浓度进行了研究.结果表明,光合茵群在初始细胞浓度0.2～O.3 g/L,温度30~40℃,PH 6.0～9.0,光照强度2000～8000 Lx,丁酸浓度6～30 mmol/L的范围内均可以保持较高的产氢效率.当初始细胞浓度为0.3 g/L、温度30℃、初始PH 7.0、光照强度为4000 Lx、丁酸浓度为30 mmol/L时该光合茵群具有最大产氢量364 mL,最大产氢效率5.4 mol-H_2/mol-丁酸和最大产氢速率22.2 mL/L/h.     

十六烷基三甲基溴化铵强化产氢发酵

微生物发酵产生的生物气要经过细胞膜释放出去,产氢菌胞外膜的通透性影响产氢发酵过程。本文研究了十六烷基三甲基溴化铵(CTAB)对混合菌胞外膜通透性和厌氧产氢发酵过程的影响。研究结果表明:浓度大于0.009 5 g/L的CTAB可有效提高混合菌胞外膜的通透性;浓度小于0.045 0 g/L时,CTAB对发酵终端的生物量和pH无明显影响;在0.009 5⁰.027 0 g/L的CTAB条件下,发酵体系的产氢速率和累计产氢量随着CTAB浓度的增加而增加;在0.027 0 g/L的CTAB条件下,获得最大产氢速率19.6 mL/h和最大产氢效率13.6 mmol每克木糖,分别较未添加CTAB时提高44%和38%;在0.045 0 g/L的CTAB条件下,混合菌产氢能力受到明显抑制。这些研究结果表明:合适浓度的CTAB可以作为一种高效的生物活化剂用于强化厌氧产氢发酵。     

利用克雷伯氏菌进行同步糖化发酵产氢的研究

氢作为一种清洁的能源引起了人们的普遍重视.实验以产酸克雷伯氏菌(Klebsiella oxytoca)HP1为产氢菌株,以稻草粉为产氢底物,进行同步糖化发酵(Simultaneous Saccharification and Fermentation,SSF)产氢.对影响同步糖化发酵产氢的单因子进行试验,选取对氢产率影响较大的因子:温度、pH、纤维素酶用量等进行L9(34)正交试验.结果表明同步糖化发酵产氢的最佳条件为:温度40℃,pH6.5,纤维素酶用量为20FPAU/g稻草粉,摇床转速100r/min,发酵时间42h.在该条件下的最大氢产率为110.6mL/g稻草粉,稻草粉的氢转化率为22%.进行了10L放大发酵产氢试验,最大氢产率为122.3mL/g稻草粉,氢转化率为24.3%.与分步糖化发酵(Separate Hydrolysis and Fermentation,SHF)产氢相比,氢产率提高34.4%.研究表明,利用同步糖化发酵工艺可以提高生物制氢的产量和得率.     

厌氧活性污泥发酵制氢系统中的同型产乙酸菌及耗氢作用

 在对连续流搅拌槽式反应器(CSTR)发酵产氢系统中的活性污泥进行分子生物学分析,判断系统中有同型产乙酸菌存在的基础上,通过活性污泥的间歇培养试验,探讨了同型产乙酸作用对活性污泥发酵系统产氢效能的影响.结果表明,CSTR发酵产氢系统的活性污泥中,一种隶属真杆菌属(Eubacterium)的同型产乙酸菌在活性污泥微生物群落中达到了优势程度;以葡萄糖为底物时,同型产乙酸菌的耗氢代谢,可使厌氧活性污泥对葡萄糖的氢气转化率及产氢率分别降低31%和34%,耗氢速率可达0.33mmol/(g·d).     

克雷伯菌HQ-3厌氧发酵产氢培养基的优化

运用Plackett-Burman设计实验结合SAS数据分析对基于克雷伯菌HQ-3(Klebsiellasp.HQ-3)产氢培养基的主效因素进行筛选,确定产氢培养基的主效因素,利用最陡爬坡实验确定主效因素的响应面中心值,用响应面法和Matlab7.0对厌氧发酵的产氢培养基的主效因子进行了优化.得到的优化的产氢培养基(YH培养基)为:Na2HPO4.12H2O,15.0g/L;KH2PO4,7.7g/L;MgSO4.7H2O,3.7g/L;葡萄糖,21.4g/L;蛋白胨,18.1g/L;酵母膏,8.0g/L;pH=8.3.利用优化的培养基进行厌氧发酵产氢验证,得到最大产氢量为826.3mL/L,与预测值806.0mL/L基本相符.并且优化培养基较初始培养基产氢量621.2mL/L,提高了33%.在最优发酵条件下,对发酵液相产物乙醇、甲酸、乙酸、丙酸、正丁酸、异丁酸进行测定,发现乙醇、甲酸、乙酸含量占总液相产物的93%,确定其发酵类型为混合酸途径.     

霉菌菌丝球对重金属Cr(Ⅵ)的吸附特性

自活性污泥中筛选到一株对重金属Cr(VI)有很强吸附能力的霉菌菌株G-28。结果表明,G-28菌丝球吸附铬的适宜pH为1.0~3.0,适宜温度为20~45℃。在Cr(VI)初始浓度10~60 mg.L-1范围内,G-28对Cr(VI)吸附效果明显。该菌株吸附铬的适宜摇速为150~180 r.min-1,吸附率达98.2%~98.8%。培养48 h的菌丝球对Cr(VI)的吸附率最大。吸附动力学研究表明,G-28对铬的吸附0~2h是一个快速过程,而2~12 h为慢吸附过程,12 h后趋于平衡。G-28菌丝球灭活后,仍具有较强的吸附能力。G-28对电镀废水Cr(VI)的吸附率高达99.1%。     

混合培养系统厌氧发酵同步产氢产乙醇研究(英文)

采用连续流槽式搅拌反应系统(ACSTR)作为反应装置,以制糖废水为底物,污水处理厂剩余污泥为反应的启动污泥,着重研究底物质量浓度和HRT对系统同步产氢产乙醇性能的影响.结果表明,在不同的底物质量浓度和HRT条件下,乙醇产量和氢气产量有着相同的变化趋势.当底物质量浓度和HRT分别为6 g COD/L和6 h时,乙醇和氢气产量分别为1.62/7.25 mmol/(L·h)and 2.97/8.73 mmol/(L·h).线性分析发现乙醇产量和氢气产量之间有很好的相关性,线性方程分别为y=0.156 6x+0.4487(r2=0.8778)和y=0.148 8x+1.671 4(r2=0.9838).     

底物浓度对光合产氢过程动力学的影响

以光合产氢混合菌种为研究对象,采用实验研究和模型拟合的方法进行底物浓度对产氢过程动力学影响的研究.结果表明,底物浓度为5、10 mg/mL的产氢系统,底物消耗利用程度较高,20 mg/mL的系统存在未完全降解利用的物质,底物最大消耗利用量为17.014 6 mg/mL.各产氢系的统产氢速率分别在95、101、107 h达到最大,即底物浓度低,光合细菌对底物的消耗利用程度高,最大产氢速率出现较早. Gompertz模型拟合氢气生成的相关系数均大于99%,且氢气生成和底物消耗主要在混合菌种对数生长期和稳定期前期.     

同型产乙酸菌株CA3及其发酵葡萄糖产乙酸条件优化

 同型产乙酸菌纯培养物的获得,可为研究其在厌氧生物处理系统中的生理生态功能以及生产化工溶剂乙酸提供种质资源。以CO₂为碳源,采用改良Hungate厌氧技术,从厌氧活性污泥中分离得到一株同型产乙酸菌CA3。该菌株为严格厌氧,卵形,G⁺,可利用H₂/CO₂产乙酸,也能发酵葡萄糖、果糖等产生乙酸。16SrRNA基因序列比对及系统发育树构建结果表明,CA3隶属Blautia sp.。菌株CA3能在20~45℃的温度范围内生长,最适生长温度为35℃,最适初始pH值为8.0。在最适条件下,菌株CA3利用H₂/CO₂产乙酸速率可达8.92mg/(L·h);以酵母粉作为氮源发酵葡萄糖时,发酵体系的乙酸浓度可达1370mg/L。     

土曲霉M11液体发酵时菌丝球形态与发酵产酶的关系

在不同的培养条件(如接种量、初始pH、温度、转速、不同碳氮源等)下,对土曲霉M11菌丝球的形态与产酶量的关系进行了深入研究,可以观察到有3种基本的菌丝球形态:丝状体、团块和球形,并且大小与致密度有明显差异.结果表明,即使在不同培养条件下,大小一致、致密的球形菌丝球(直径1～2 mm)都具有最高的产酶量,菌丝球的形态与真菌产酶量密切相关.因此,在工业发酵产酶过程中,对菌丝球形态的检测,可以作为一种关键的指标来检测发酵的效果.     

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…     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.