不同放牧强度对红三叶、黑麦草草地植被和土壤养分的影响

对不同放牧强度下草地植物和土壤的变化规律进行了研究，结果表明：３年强度放牧使土壤的全氮含量和草地的组成和结构发生了较大的变化，使牧草产量下降１７．１％，草地主要种红三叶的重要值降低了３３．８％，均质度系数增加５１．１％，土壤的氮磷比升高１．３。轻度放牧使草地全氮含量降低０．０９６％，红三叶的均质度系数增加２１．０％。中度放牧并未使草地牧草产量和红三叶的重要值降低，同时使草地红三叶均质度系数保持在远低于１．０水平以下，但使土壤全氮含量下降０．０８５％。根据以上结果，中度放牧是保持草地持续高产的最好的放牧管理选择。     

A/O工艺曝气量控制及pH和DO的变化规律

对A/O工艺研究了不同运行条件下曝气量对硝化过程的影响,以及好氧区pH和DO浓度的变化规律。发现随着曝气量的增加,平均硝化反应速率提高,平均DO浓度增加,但增加幅度降低。需通过控制曝气量大小,间接的控制硝化反应速率,使出水达标排放。可以应用平均溶解氧浓度和pH曲线上是否出现拐点,来判断反应系统的曝气是否过量、适量或不足。     

曝气生物滤池与类似传统工艺的比较

就生物滤池、生物接触氧化、曝气生物滤池三种同为生物膜法的工艺技术在原理、特点、适用范围、经济性能等方面作了比较，为水处理的工艺选择提供了依据。     

Partitioning of resources in production: an empirical analysis

Industrial economies ingest materials, energy and information to produce goods and services and excrete wastes and emissions. Wastes can be minimized and the relative amounts of resources, which go into goods and services, as opposed to waste, are essential to clean production and to the sustainability of the production system. A regression model based on empirical data is presented that provides a partition coefficient expressing the ratio of energy (or material) resources invested in goods to energy going to waste. Partition coefficients are developed for five countries and are shown to be related to GDP, energy and material consumption and energy and waste intensities. Higher partition coefficients mean higher productivity and lower energy, waste and material intensities. In addition, energy use/capita and pollution/capita is lower. The price of energy to the industrial sector is related to the partition coefficient. The policy implications are that partitioning of resources to goods should be maximized and waste minimized for economic as well as environmental reasons.     

中小型造纸厂造纸废水处理

针对中小型造纸厂造纸废水处理的特点，分析讨论了采用混凝与生化处理相结合的工艺，处理中小型纸厂造纸废水的可行性，并在实验室条件下研究了生化处理过程中曝气强度、ｐＨ值等因素对ＣＯＤＣｒ去除率的影响     

间歇曝气A2/C氧化沟工艺处理城市污水中试研究

为降低氧化沟工艺的运行成本,研究了连续进水间歇曝气缺氧(Anoxic)-厌氧(Anaerobic)-Carrousel氧化沟(A2/C)工艺.采用A2/C氧化沟模型运用连续进水间歇曝气模式对城市污水处理进行了研究.结果表明,增强外源反硝化是提高脱氮效率的关键.在一定范围内加大回流比,能够提高间歇频率,减小各污染指标在反应系统中的积累.在曝气1 h,停止曝气3 h,回流污泥比200%的模式下(模式Ⅱ),出水CODcr,NH4 -N和TN分别为40～50 mg·L-1、3.0～5.7 mg·L-1和10.2～12.5 mg·L-1.3个模式在1个周期内平均曝气量分别为连续曝气过程的66%、50%、44%.模式Ⅱ中在线监测仪表数据分析显示,曝气过程中出现NH4 -N氧化的终点--在pH曲线上表现为出现"氨谷",若利用在线监测仪表在曝气阶段采用自动控制,则可避免过量曝气.采用实际城市污水,应用中试试验模型,能够为实际生产提供重要技术参数,为原有氧化沟工艺技术改造提供支持.     

天津市经济—环境系统的物质流分析

利用物质流分析工具对天津市经济—环境系统中的物质流进行了分析,分析结果表明:2004年天津市的物质需求总量达到8.68亿t,且增长趋势明显,其中基础设施建设对环境造成了较大扰动,进口物质大于出口物质;城市环境容量总体处于饱和状态,水体污染严重;物质消耗强度不断增长,资源的利用效率处于较低水平。最后,针对存在的问题,提出相应的措施和建议。     

Applications of Venturi Principle to Water Aeration Systems

The concentration of dissolved oxygen is an important indicator of water quality because aquatic life lives on the dissolved oxygen in the water. Aeration can increase dissolved oxygen when levels become deficient. Hydraulic structures can significantly improve dissolved oxygen levels by creating turbulent conditions where small air bubbles are carried into the bulk of the flow. Recent researches have focused on developing measurement and predictive techniques for oxygen transfer at hydraulic structures to maintain and enhance water quality. However, reviewing existing studies on aeration performance of hydraulic structures, it seems that there are not too many studies on venturi aeration. The present paper shows applications of venturi principle to water aeration systems. The aeration characteristics of venturi nozzle, venturi conduit and venturi weir are analyzed. The results indicate that venturi aeration might contribute significantly to air entrainment and aeration efficiency. Therefore, venturi device can be used as highly effective aerator in aeration processes.     

猪粪混合堆肥过程中重金属含量的变化

在猪粪混合堆肥中，采用不同的通风方式和填充料，分析该过程中重金属总量和DTPA提取的重金属含量变化。结果表明，通过猪粪混合堆肥，重金属总量不会降低，但重金属生物有效性可降低；在猪粪与木屑混合堆肥中，加入树叶或鸡粪均能显著降低重金属的生物有效性，强制通风 机械翻堆比单一机械翻堆更能降低重金属的生物有效性。     

Vocalizations and courtship intensity correlate with mounting success in marginated tortoises<Emphasis Type="Italic"> Testudo marginata</Emphasis>

The courtship and mounting behaviour of tortoises is elaborate, and based on a multiple signalling system involving visual, olfactory and acoustic signals. Vocalizations related to mounting seem to be particularly significant because tortoises vocalize mainly at this time. Vocalizations and courtship behaviour may be costly for males, and if these costs increase differentially for different males, then the potential exists for vocalizations and displays to reveal male individual quality. In this correlative study, we analysed relationships between male mounting success and morphological and behavioural traits, particularly acoustic signals, exhibited by male marginated tortoises (Testudo marginata) during courtship, in a group of 94 individuals breeding in semi-natural enclosures. For each male, we estimated general body condition, courtship intensity and mounting success; calls of mounting males were recorded and four sonagraphic features were measured. Calls differed significantly among males, and two features varied according to body condition. Male mounting success significantly increased according to the male/female size-ratio, suggesting the existence of a size-based assortative mating. Mounting success was also highly correlated with courtship intensity, measured as number of bites and rams given to females before mounting, and with number of calls emitted during mounting. Finally, mounting success was negatively related to call duration. To our knowledge, this is the first study in which features of tortoise vocalizations are shown to convey reliable information about male quality in socio-sexual contexts.Communicated by T. Czeschlik