数学实验揭示的岩体声发射参数变化

对非均匀性材料的破坏过程进行数学实验。方法是用随机数值矩阵描述岩石材料的非均匀性 ,依据矩阵数值大小与图形亮度的对应关系 ,用不同亮度的图形单元表示不同岩石单元的受力和声发射状态。单元超过受力极限时破裂产生声发射。模拟材料受外荷载时的变化并且计算了几个声发射参数的变化。结果表明破裂过程中不同声发射事件的距离、能量和频数及其差分的变化趋势高度一致。在此基础上建立了安全系数与距离、能量和频数及其差分的关系。对得到的数值进行归一化处理 ,可用来预报岩石材料的安全状况或破裂危险。     

油田单井清洁生产探讨

江苏油田某基层采油队边远单井为例,对单井实施清洁生产现状和问题进行分析,从单井采油生产地面工程配套工艺技术、清洁生产配套工艺等方面,探索单井实施清洁生产的有效措施和办法.     

淮北平原“四水”转化模型实验研究与应用

论文基于野外实验,采用五道沟实验站和杨楼实验区1965-2007年长系列资料,考虑土壤水垂向运动和再分布、冠层截留、蒸发、填洼、大孔隙、潜水排出补给地表水等要素,采用野外实验数据逐步细化和确定参数,提出淮北平原集总式“四水”转化模型,并提出一种新的冠层截留量年内分布确定方法。模型物理意义明确,对资料的要求较低,实用性较强。模型在杨楼流域应用结果表明,模拟流量过程线精度较高,在潜水位变动过线的拟合上效果较优,在径流过程和土壤含水量的拟合上表现较好。通过模型逐年计算统计,得出杨楼实验流域1991-2007年逐年及多年平均“四水”转化定量关系,为该区水文预报和作物水利用提供技术依据。     

气升式氧化沟污水处理效果的中试研究

在太湖流域某小城镇污水处理厂研究中试气升式氧化沟的污水处理效果,获取了出水主要指标稳定达标的工艺参数.结果表明,出水COD<50mg/L的最大容积负荷为0.88kg/(m3·d).NH4+–N污泥负荷不大于0.06kg /(kg·d)时,出水能达到排放标准要求的5 mg/L.直沟段DO降低到0.6~1.0mg/L后,进出水TN平均浓度分别为30.7,11.3mg/L,并能保证出水TN<15 mg/L稳定运行14d以上.进气量30m3/h时,直段底部最大流速为0.19m/s,中上部流速为0.03m/s,此时沟底没有出现污泥沉降,出水各项指标稳定达标.生产型气升式氧化沟的占地面积将比传统氧化沟至少减少25%.     

Trophic field overlap: A new approach to quantify keystone species

It is a current challenge to better understand the relative importance of species in ecosystems, and the network perspective is able to offer quantitative tools for this. It is plausible to assume, in general, that well-linked species, being key interactors, are also more important for the community. Recently a number of methods have been suggested for quantifying the network position of species in ecological networks (like the topological importance metric, TI). Most of them are based on node centrality indices and it may happen that the two most important species in a food web have very similar interaction structure and they can essentially replace each other if one becomes extinct. For conservation considerations it is a challenge to identify species that are richly connected and, at the same time, have a relatively unique and irreplaceable interaction pattern. We present a new method and illustrate our approach by using the Kuosheng Bay trophic network in Taiwan. The new method is based on the interaction matrix, where the strength of the interaction between nodes i and j depends only on topology. By defining a threshold separating weak and strong interactors, we define the effective range of interactions for each graph node. If the overlaps between pairs of these ranges are quantified, we gain a metric expressing how unique is the interaction pattern of a focal node (TO). The combination of centrality (TI) and uniqueness (TO) is called topological functionality (TF). We compare the nodal importance rank provided by this metric to others based on a variety of centrality measures. The main conclusion is that shrimps seem to have the most unique interaction pattern despite that their structural importance has been underestimated by all conventional centrality indices. Also, our network analysis suggests that fisheries disturb the ecosystem in a more critical network position than the impingement by the local power plant.     

Paternity alone does not predict long-term investment in juveniles by male baboons

Adult male chacma baboons (Papio hamadryas ursinus) form preferential associations, or friendships, with particular lactating females. Males exhibit high levels of affiliative contact with their friends’ infants and defend them from potentially infanticidal attacks (Palombit et al. 1997). Little is known about males’ associations with juveniles once they have passed the period of infanticidal risk. We conducted an observational, experimental, and genetic study of adult male and juvenile chacma baboons in the Moremi Reserve, Botswana. We identified preferential associations between males and juveniles and used behavioral data and a playback experiment to explore whether those associations have potential fitness benefits for juveniles. We determined whether males preferentially invest in care of their own offspring. We also determined how often males invest in care of their former friends’ offspring. The majority of juveniles exhibited preferential associations with one or two males, who had almost always been their mother’s friend during infancy. However, in only a subset of these relationships was the male the actual father, in part because many fathers died or disappeared before their offspring were weaned. Male caretakers intervened on behalf of their juvenile associates in social conflicts more often than they intervened on behalf of unconnected juveniles, and they did not appear to differentiate between genetic offspring and unrelated associates. Playbacks of juveniles’ distress calls elicited a stronger response from their caretakers than from control males. Chacma males may provide care to unrelated offspring of former friends because the costs associated with such care are low compared with the potentially high fitness costs of refusing aid to a juvenile who is a possible offspring.     

Hierarchical modeling for extreme values observed over space and time

We propose a hierarchical modeling approach for explaining a collection of spatially referenced time series of extreme values. We assume that the observations follow generalized extreme value (GEV) distributions whose locations and scales are jointly spatially dependent where the dependence is captured using multivariate Markov random field models specified through coregionalization. In addition, there is temporal dependence in the locations. There are various ways to provide appropriate specifications; we consider four choices. The models can be fitted using a Markov Chain Monte Carlo (MCMC) algorithm to enable inference for parameters and to provide spatio–temporal predictions. We fit the models to a set of gridded interpolated precipitation data collected over a 50-year period for the Cape Floristic Region in South Africa, summarizing results for what appears to be the best choice of model.

壳聚糖负载膨润土处理高浊度废水的效果

以天然膨润土为原料,壳聚糖为改性剂,采用微波改性技术制备了壳聚糖负载膨润土,应用于高浊度废水的处理.通过正交试验确定了废水处理工艺各种影响因素的最佳条件.比较了负载土、原土、壳聚糖的处理效果,结果表明:负载土对高浊度废水的去浊效果明显好于原土、壳聚糖;对于浊度为9250～9480 NTU的废水,经30 min自由沉降后,在投土量为4.0 g·L~(-1)、投土粒度为0.150 mm、搅拌速度为100 r·min~(-1)、搅拌时间为10 min的条件下,废水剩余浊度为6.0～7.0 NTU,浊度去除率高达99.9%.出水水质满足<再生水作循环冷却水水质>的水质要求.     

纤毛状生物膜脱氮除磷工艺调试研究

纤毛状生物膜脱氮除磷工艺(CNR)是一种高效的生物脱氮除磷工艺.好氧池中纤毛状生物膜填料的添加,固化了大量世代时间长的硝化菌,提高了硝化反应速度,而且成功地解决了好氧段硝化菌与聚磷菌的泥龄矛盾.通过对天津某污水处理厂进行CNR工艺中试,得出结论如下:填料比表面积大,微生物附着量高达1 350～1 500g·m~(-2);填料容易挂膜、脱膜,无堵塞现象,更不需要反冲洗,维护管理简单;填料上形成的生物膜中,微生物体系稳定,种群丰富,微生物相包括钟虫(vorticella)、轮虫(rotaria)、表壳虫(arcella)、吸管虫(tokophrya)等;采用CNR工艺对污水处理,常规项目的去除率均达到80%以上,出水水质除总氮达到一级B标准,其他均达到<城镇污水处理厂污染物排放标准>(GB 18918-2002)的一级A排放标准.     

部分菊科入侵种种子(瘦果)的萌发能力和幼苗建群特性

对入侵种种子生物学各方面的了解有助于更好地预测入侵趋势和评估可持续管理的策略.研究通过对部分菊科入侵种种子(瘦果)进行的室内萌发实验和土壤埋藏实验,通过与相关研究的对比和分析,对这些入侵种的萌发能力和幼苗建群特性进行了研究.10个入侵种种子室内萌发实验的结果表明,在25℃、12h光照的情况下,除钻形紫菀和一年蓬以外,被研究的其它8个种的终萌发率超过了50%,而且都显示出早期快速萌发的特点.用SPSS的曲线拟合工具对10个种的累积萌发趋势进行了曲线回归分析,对应的最佳模型均为三次曲线方程.不同土壤埋藏深度下幼苗出苗实验的结果表明,菊科8个入侵种的种子在表土的出苗率均最高,随着覆土厚度的增加,种子的出苗率逐渐降低,当覆土厚度超过3 cm以上时,所有种子均不能出苗.种子在不同的埋藏深度的出苗情况与种子的大小有关,较大种子破土能力相对较强;种子在不同的埋藏深度的出苗情况与种子本身的萌发能力也相关.土壤埋藏期限的实验结果表明,随埋藏时期的增加,小蓬草、苏门白酒草和一年蓬3个人侵种种子的活力逐步降低,在土壤中埋藏12个月后,其活力分别为21.34%、18.15%和27.38%.这些入侵种较广的种子萌发温度适应范围和高萌发率为防除工作带来了困难.在生产上,可通过不同时期的翻耕、将种子深埋等措施减少这些入侵种的危害.