Dynamics of total culturable bacteria and its relationship with methylmercury in the soils of the water level fluctuation zone of the Three Gorges Reservoir

Field investigations were conducted to study the temporal and spatial distribution characteristics of total culturable bacteria(TCB)and its relationship with methylmercury(MeHg)in the soils of the water level fluctuation zone of the Three Gorges Reservoir.Different altitudes(170–180,170–175,165–170 and 160–165 m)in Zhenxi(Site 1),Shibaozhai(Site 2)and Tujing(Site 3),Chongqing,China were chosen as sampling sites.Results indicated that TCB did not have significant difference in the top(0–10 cm)and sub(10–20 cm)soil of the non-inundated area(175–180 m),but showing a significant difference in the water level fluctuation zone(\175 m,suggesting that water level fluctuation had an important effect on TCB.Moreover,TCB in soils of various altitudes of Site 1 and 2had significant difference,while for Site 3,this difference was not significant.And the difference of TCB in Site 2was much greater than that in Site 1.These results suggested that there were significant differences for TCB in soils of mainstream and tributaries.In addition,TCB in soils of 10–20 cm had significant or highly significant positive correlations with MeHg level(r C 0.762,P B 0.048),thus we assumed that there may be some aerobic microorganisms playing dominant roles in mercury methylation.     

Spatial distribution of bacterial community in EGSB reactor treating synthetic sulfate-containing wastewater at low organic loading rate

Given that the consumption of organic sub- stances entails costly biodesulfurization, the characteristics of the bacterial community in a reactor should be deter- mined to increase the desulfurizing rate under low organic loading condition. In this study, the bacterial community distribution in the expanded granular sludge bed reactor used to treat sulfate-containing wastewater with low organic loading rate was determined by polymerase chain reaction-denaturing gradient gel electrophoresis （PCR- DGGE） and 16S rDNA clone library analyses. DGGE results showed that the predominant bacteria were stable and accounted for -90 % sulfate removal efficiency. Differences in band positions and intensities indicated that the distribution and abundance of bacteria were affected by their positions in the reactor. Typical bands were identified in the bacterial community comprising Desulfovibrio, Desulfomicrobium, Thiomonas, Acinetobacter, Bacteroi- detes, and Chloroflexi. Their functions in the reactor were also discussed. The possible links between the functional and microbial responses were also investigated based on the characteristic and spatial distribution of each bacterium in consortium.     

摄动理论与多时标方法在大系统降阶中的应用

非奇异摄功和奇异摄动理论在系统科学中的应用,是近几年来国际上出现的一个新的学术分支。这一理论的多时标方法在大系统降阶中得到了成功的发展。本文综述有关概念和主要研究成果,介绍线性系统时标分解的迭代法和测度法,并通过例子说明理论与方法的成功应用。     

广义双连对角占优矩阵

引入广义双连对角占优矩阵的概念,证明广义双连对角占优的可逆性,讨论它们与Ｍ矩阵的关系,并给出了广义双连对角占优矩阵特征值的一些性质．     

番茄汁乳酸菌发酵饮料的研制

以番茄为原料,经乳酸菌发酵而制成番茄汁乳酸菌发酵饮料,通过对接种量、发酵时间、发酵温度、风味、稳定性进行实验,从而确定出最佳工艺参数为：接种量５％,发酵温度４０℃,发酵时间３０ｈ,黄原胶０．０３％,耐酸性ＣＭＣ－Ｎａ０．０２％。     

转CaM基因工程菌的培养及重组钙调素的提纯

研究了转植物ＣａＭ基因的大肠杆菌的培养以及从该工程菌中分离纯化ＣａＭ的方法,观察到在含氨苄青霉素及氯菌素的ＬＢ液体培养其中,     

小麦内生菌的分离与鉴定

试验从武汉市郊6个地块的小麦中分期、分部位取样,采用常规的细菌分离方法分离到26株内生菌,经形态学、培养及生理生化特征鉴定,它们分别属于蜡状芽孢杆菌(B.cereus)、多粘芽孢杆菌(B.polymyra)、巨大芽孢杆菌(B.negaterium)、坚强芽孢杆菌(B.fiuum)和草状芽孢杆菌(B.mycoides).     

黄东海多毛类动物种类组成与优势种分析

【目的】探明黄东海区域多毛类Polychaeta物种组成状况。【方法】用0.1 m2 Gray-O’Hara箱式采泥器重复采样2次,对获得的多毛类样品进行准确的分类鉴定,采用优势度计算公式:Y=(ni/N)fi统计得出优势种并分析其空间分布状况。【结果】本次调查黄东海共鉴定出多毛类32个科90种,优势种为背蚓虫Notomastus latericeus Sars,1857和掌鳃索沙蚕Ninoe palmata Moore,1903,其分布没有表现出明显的规律性。【结论】黄东海多毛类种类丰富,优势种随时间变化而改变,而分类学研究应引起重视。     

数据显断层与数据隐断层的研究与应用

建立能够和谐平衡各个信息系统之间数据断层的机制是实现管理决策变革最关键的3大基础之一,也是智能决策支持系统研究领域的重点内容之一.随着互联网+时代的到来,各式各样的数据资源不断积累,数据断层现象在多个领域表现得愈加明显.通过对数据断层理论体系的进一步研究与实践,着重分析微观层面的数据断层现象,一方面用显断层概念描述各系统之间以及系统内部存在的较为明显的断层现象,另一方面用隐断层概念描述各系统之间以及系统内部存在的非明显的断层现象,并在数据显断层中引入缝隙的概念来描述主题无关数据对象,采用数据聚合的技术手段来降低缝隙数据的断层属性,同时在隐断层中引入"有效密度"来形象地描绘数据分布情况,通过数据熔合来减少无效数据占用的空间.最后以上海"动感101"音乐电台的移动客户端应用日志数据为例,分析了电台数据中所存在的数据显断层和数据隐断层现象.     

考虑网络平台服务、消费者需求差异的混合供应链决策

文章研究了由制造商、零售商和网络平台构成的混合供应链系统,构建了混合供应链4种不同的模式:M-M-HSC模式,N-M-HSC模式,M-R-HSC模式和N-R-HSC模式,给出各个模式相应的定价、佣金以及利润等决策,分析消费者需求差异对各个模式运行的影响.研究表明:1)网络平台收取的佣金主要受制造商主导地位的影响,在M-R-HSC模式中,佣金以及网络平台的利润随着消费者网购偏好的增加而增加;在其他模式中,佣金以及网络平台的利润随着消费者网购偏好的增加呈现先增后减的趋势.2)产品的批发价格主要受制造商在传统渠道中的主导权影响,产品的网上销售价格主要受制造商在E-供应链中的主导权力影响.而且无论是产品的批发价格,网上销售价格还是制造商的利润,混合供应链的利润都随着消费者网络偏好的增加而增加.3)在4种模式中,零售商的利润及零售价格的大小是一一对应的,价格和利润都在M-R-HSC模式中最高,在N-M-HSC模式中最低.而且零售价格和零售商的利润随着消费者网购偏好系数的增加而减少.4)制造商主导混合供应链的运作模式有利于系统的运行.这些研究结论会进一步丰富发展混合供应链的理论基础,有利于供应链企业的运营发展.