密闭培养对纤细角毛藻稳定同位素组成的影响

为研究碳源对赤潮藻生长的影响,以赤潮藻纤细角毛藻（Chaetoceros gracilis）为研究对象,在密闭条件下进行培养,模拟赤潮发生时碳源缺乏的生长环境;分析碳源不足对纤细角毛藻不同生长阶段的差异影响,采用密闭培养的方法,分别在正常组和缺氮组的营养条件下培养纤细角毛藻,测定生物量、营养盐浓度和碳氮稳定同位素组成等重要监测指标.结果表明:不同营养条件对纤细角毛藻的生物量存在显著影响.在正常组,c（NO₃--N）（NO₃--N为硝酸盐）随着培养时间呈下降趋势,ρ（NO₂--N）（NO₂--N为亚硝酸盐）和ρ（NH₄+-N）（NH₄+-N为铵盐）与藻类生物量呈显著正相关,ρ（PO₄3--P）（PO₄3--P为磷酸盐）和c（SiO₄2--Si）（SiO₄2--Si为硅酸盐）与藻类生物量呈显著负相关;在缺氮组,c（NO₃--N）、ρ（NO₂--N）、ρ（NH₄+-N）、ρ（PO₄3--P）和c（SiO₄2--Si）均与藻类生物量呈显著负相关.整个试验周期中,正常组和缺氮组δ13C和δ15N值越来越正.其中,正常组的δ13C值比缺氮组的更正,平均高2.286‰;缺氮组的δ15N值比正常组的更正,平均高3.307‰.正常组和缺氮组的δ13C、δ15N值与生物量均呈显著正相关.研究显示,碳源和氮源的不足分别会导致更正的δ13C和δ15N值,推测赤潮发生会导致δ13C和δ15N值偏正,赤潮藻的碳氮稳定同位素组成可以作为赤潮监测的指标和方法.      

Propagation of ethylene–air flames in closed cylindrical vessels with asymmetrical ignition

A study of explosions in several elongated cylindrical vessels with length to diameter L/D = 2.4–20.7 and ignition at vessel's bottom is reported. Ethylene–air mixtures with variable concentration between 3.0 and 10.0 vol% and pressures between 0.30 and 1.80 bara were experimentally investigated at ambient initial temperature. For the whole range of ethylene concentration, several characteristic stages of flame propagation were observed. The height and rate of pressure rise in these stages were found to depend on ethylene concentration, on volume and asymmetry ratio L/D of each vessel. High rates of pressure rise were found in the early stage; in later stages lower rates of pressure rise were observed due to the increase of heat losses. The peak explosion pressures and the maximum rates of pressure rise differ strongly from those measured in centrally ignited explosions, in all examined vessels. In elongated vessels, smooth p(t) records have been obtained for the explosions of lean C₂H₄–air mixtures. In stoichiometric and rich mixtures, pressure oscillations appear even at initial pressures below ambient, resulting in significant overpressures as compared to compact vessels. In the stoichiometric mixture, the frequency of the oscillations was close to the fundamental characteristic frequency of the tube.     

封闭空间火焰自熄灭时间数值模拟研究

利用CFD数值模拟研究封闭空间内甲烷燃烧火焰在常重力和微重力两种环境中自熄灭时间的不同,分析火焰自熄灭时间与火源热释放速率、封闭空间体积、重力之间的关系。结果表明:当火源热释放速率一定时,微重力环境中火焰自熄灭时间数倍于常重力环境中的情况。当封闭空间体积一定时,小火源功率在微重力环境中的自熄灭时间远大于常重力环境中的情况。因此,微重力环境中不宜采用窒息灭火法。     

阿克苏地区春季土壤水分垂直向运动

土壤中毛管水是传递压力的,毛管水运动的方向,受土壤上层温度变化和土面蒸发制约,与土壤中汽态水的运动方向（由热至冷）一致。下午和晚上因地面辐射而冷却,闭塞空气收缩,潜水向上通过毛细管吸入闭塞空气中,潜水位下降;上午和白天因地面日晒,土温升高,闭塞空气膨胀,排出较粗毛管水,成为重力水而下渗,抬升潜水位。春天大风,土温升高,晚上使潜水位升高,白天土面蒸发加大,又使潜水位下降。用潜水蒸渗仪,可测到大风天改变土壤水分运行的方向。     

废纸制浆造纸废水封闭循环处理工艺

本文介绍了废纸造纸制浆废水的特点、在零排放和废水封闭循环中遇到的问题以及解决措施，介绍了几种目前比较常用的废纸制浆连纸循环水处理工艺及其发展状况。     

Information in the Animate and Inanimate Worlds

Closed systems are governed by the second law of thermodynamics and cannot spontaneously become more ordered. In open physical systems exposed to external energy flows, additional macroscopic degrees of freedom (memory cells) emerge, their number increasing with an increase in the flow and orderliness of the external energy. Biological systems are characterized by molecular degrees of freedom, the density of which is more than twenty orders of magnitude higher than that of macroscopic degrees of freedom in any open physical system exposed to the same external energy flow. This indicates that the self-organization of physical systems in external energy flows and the self-organization and evolution of living systems are fundamentally different. Thus, although life is an open system, the energy (food) flows that it consumes and all other external factors affecting life are so poorly ordered, compared to life itself, that they cannot increase the degree of order in the latter. Therefore, living systems obey an analogue of the second law of thermodynamics: within periods of time considerably shorter than the duration of evolutionary changes, living systems can only lose the accumulated information (i.e., the entropy can only increase), even if the systems consume external energy–food flows.     

养殖塘CH4通量时空变化特征及其影响因素

本研究基于多通道密闭式动态箱法对亚热带典型养殖塘CH₄通量的时空变化特征及其影响因素进行了分析.结果表明：亚热带养殖塘CH₄主要排放方式是冒泡,CH₄扩散及冒泡通量均呈现明显的季节变化特征.春、夏、秋、冬4个季节CH₄扩散通量分别为：0.113,0.830,0.002,0.005μmol/（m²·s）,冒泡通量分别为0.923,1.789,0.006,0.007μmol/（m²·s）,冒泡通量占总通量的比例分别为89.04%、68.29%、78.95%和60.52%.在冬、春季养殖塘没有人工管理措施的情况下,CH₄通量随着离岸距离的增加而增大,冬、春季养殖塘中间区域CH₄总通量分别是岸边浅水区的34.70和2.98倍.夏季养殖活跃期CH₄通量在空间上呈现出：人工投食区（7.371μmol/（m²·s））>自然生长区（2.151μmol/（m²·s））>人工增氧区（0.888μmol/（m²·s））>岸边浅水区（0.206μmol/（m²·s））的特征.在0.5h尺度上,春季CH₄扩散通量与水温呈显著正相关关系,与风速呈负相关关系,秋季CH₄扩散通量与水温、风速呈正相关关系,冒泡通量和水温呈正相关关系.在日尺度上,水温是CH₄扩散通量和冒泡通量的主控因子,两者均随着水温升高呈指数增加,并且冒泡通量的水温敏感性Q₁₀（12.72）大于扩散通量（7.78）.     

开闭路条件下沉积物微生物燃料电池阳极细菌群落差异解析

采用Solixa高通量测序技术对比了沉积物微生物燃料电池(sediment microbial fuel cells,SMFCs)开闭路条件下启动阳极生物膜细菌群落结构差异.SMFCs开路条件下启动阳极生物膜获得优化序列3 936条,经过97%相似度归并后得到1 581个操作分类单元(operational taxonomic units,OTUs);SMFCs连接5 kΩ电阻闭路启动阳极生物膜获得优化序列3 930条,聚类归并后产生1 551个OTUs,α多样性指数分析表明开路条件下启动阳极生物膜菌群多样性相对更丰富.SMFCs开、闭路条件下启动阳极生物膜优势菌均为Proteobacteria、Firmicutes和Bacteroidetes,它们在开路下阳极生物膜中的含量分别为59.79%、12.54%和9.02%,而在闭路条件下分别为63.02%、10.01%和3.60%,SMFCs闭路条件下运行,地杆菌Geobacter在阳极生物膜中含量高达16.55%.SMFCs开、闭路条件下启动阳极生物膜细菌群落结构的差异说明SMFCs启动过程电子的传递影响电极生物膜微生物群落结构.     

我国区域闭合性煤炭流的时空分析

煤炭是我国最主要的一次能源,煤炭的闭合性流动反映了区域自身内部或区域之间能源经济的交互影响。利用0-1线性规划对我国8区域煤炭运输的物质流矩阵作了两个层级的分解,通过两个层级的子矩阵找出了我国1998—2007年最大两个层级的闭合性煤炭流动,并从时间和空间呈现的特征作了分析。研究结果显示:①无论是第一层级的闭合性煤炭流还是第二层级的闭合性煤炭流,短期内都没有发生大的变化,表明我国区域的资源格局以及用煤供给需求在短期内具有相对稳定性;②1998—2003年空间流动的界限分明,第一层级均为区域自身的内部流动,第二层级均为区域之间的闭合性流动。从2004年开始空间流动界限不再分明,根据第一层级的空间特征显示,我国最大的闭合性煤炭流不仅仅出现在区域内部,也出现在区域之间,表明区域与区域之间的能源经济联系有所加强。     

The study of production and inventory policy of manufacturing/remanufacturing environment in a closed-loop supply chain

The life cycle of electronic and electrical equipment has been ruthlessly shortened due to the rapid promotion of new products. Such a phenomenon has thereby resulted in serious environmental pollution and damages to the natural ecology. In order to reduce electronic wastes and increase recycling products, a manufacturing/remanufacturing simulation model was constructed through a series of inventory management policies. The model included the use of the traditional supply chain structures for the forward movement of goods to consumers, as well as a number of specialised operations required to perform reverse supply chain activities. Such a model took into account all the supply chain members such as the suppliers, manufacturers, logistics centres and customers at the same time. Finally, a case study on the application of the model was conducted.