沉降速率作为选择压对好氧颗粒污泥性质影响

在序批式反应器中以普通活性污泥驯化而得的好氧颗粒污泥为接种污泥,葡萄糖为碳源,研究作为选择压的沉降速率对好氧颗粒污泥性质的影响。结果表明:作为选择压的沉降速率与反应器中SV值和MLSS成反比关系;在沉降速率变化过程中,污泥龄、耗氧速率、胞外多聚物和COD去除率均产生变化。在本试验条件下,改变沉降速率,能改变反应器中生物量的洗出量并在一定程度上影响微生物群体的组成,从而影响活性的生物学性能;但生物相的改变限度在一定范围内,存在着动态平衡。污泥龄的波动与不同沉降速率下反应器中污泥中的胞外多聚物含量的变化有关。大量的胞外多聚物在颗粒污泥表面形成粘液层,对颗粒污泥形成保护。不同沉降速率下颗粒污泥的的胞外多聚物发生变化,进而影响颗粒污泥的稳定性。     

入侵植物加拿大一枝黄花和本地一枝黄花的遗传多样性比较

为了阐明加拿大一枝黄花成功入侵的机制,利用简单序列重复区间标记(ISSR)方法对加拿大一枝黄花和本地一枝黄花的遗传多样性进行比较研究。从100条引物中筛选出12条引物用于PCR扩增,利用POPGEN32软件对2种一枝黄花进行遗传多样性分析。结果表明,加拿大一枝黄花在物种水平上的多态位点百分率为95.19%,Nei’s基因多样性指数为0.308 5,Shannon’s信息指数为0.415 8;本地一枝黄花在物种水平上的多态位点百分率(89.80%)、Nei’s基因多样性指数(0.249 1)和Shannon’s信息指数(0.383 4)都比加拿大一枝黄花小。加拿大一枝黄花和本地一枝黄花居群间遗传分化系数分别为0.118 2和0.131 3,居群内变异分别为0.881 8和0.868 7,表明2个物种居群间的遗传分化不明显,遗传一致度高,且主要的遗传变异存在于居群内。入侵植物加拿大一枝黄花具有较高遗传多样性,且高于本地一枝黄花,这可能是加拿大一枝黄花成功入侵的原因之一。     

灰色系统方法在县域生态区划中的应用

为了反映各生态因子之间的内涵不确定性关系,通过对影响区域生态的因子的筛选,进行主成分分析,得到影响龙湾区生态环境的主要因子是各土地使用类型的分布和污染物排放量;通过灰色关联度分析获得各因子对生态影响的权值,结合"星座图"聚类方法将温州市龙湾区区划出3个生态类型,5个发展方向,并形成了对县域生态区划行之有效的方法。     

Identification of various laccases induced by anthracene and contribution to its degradation in a Mediterranean coastal pine litter

Mediterranean coastal ecosystems are known to be highly subject to natural and anthropic environmental stress. In this study, we examine the effects of anthracene as a common pollutant on the total microbial communities from a Pinus halepensis litter of a typical Mediterranean coastal site (Les Calanques, Marseille). The main objective was to identify the microbial factors leading the resilience of this ecosystem. Two questions were addressed: (i) how lignin-degrading enzymes (Laccase, Lignin-peroxidase and Mn-peroxidase) are affected by the presence of this molecule, (ii) whether the indigenous consortia are involved in its degradation in mesocosms under favorable incubation conditions (25 °C, 60% WHC) and after different time intervals (1 and 3 month(s)). We found a strong increase in laccase production in the presence of anthracene after 3 months, together with anthracene degradation (28% ± 5). Moreover 9,10-anthraquinone is detected as the product of anthracene oxidation after 3 months. However neither lignin-peroxidase activity nor Mn-peroxidase activity is detected. Laccase proteins directly extracted from litter were sequenced via Nano-LC-MS/MS and reveal twelve different peptide sequences induced by the presence of anthracene in the mesocoms. Our study confirms the major detoxification role of this enzymatic system and highlights the high degradation potential of fungal species inhabiting P. halepensis litter, a factor in the resilience of Mediterranean ecosystems.     

生物强化对MBR系统生物特性及群落结构的影响

采用高效菌强化膜生物反应器对溴氨酸废水进行处理,考察了生物强化前后系统对溴氨酸的降解能力及其内部微生物生理状态变化.并采用核糖体基因间隔序列分析技术(RISA)解析了高效菌投加前后污泥系统的群落变化.实验表明,投菌后在进水负荷增加的条件下,上清液和膜出水的溴氨酸脱色率分别约为50%和65%,相应的COD去除率分别约为25%和50%,和投菌前基本保持一致;TTC-脱氢酶活性和胞外聚合物(EPS)浓度略有波动,但是运行一段时间后即恢复到投菌前水平.群落分析表明高效菌可以在系统中稳定存在,并且不对原菌群结构造成较大影响.     

基于改进风险矩阵法的配气站地震事件序列分析

为了对天然气配气站进行抗震安全评估,以某天然气配气站为研究对象,通过分析地震事件序列,建立风险矩阵模型,研究系统失效原因及失效概率,评估事件发生后果.结果表明:事件C5,C6风险值相对较低,分别为18.75和15.24;风险矩阵模型能有效减小尖锐边界影响,为配气站采取抗震措施提供理论依据.     

一种新厌氧氨氧化菌的16S rRNA基因序列测试

运用序批式试验测定厌氧氨氧化污泥的氨氮和亚硝态氮消耗量,求得厌氧氨氧化活性为9.84×10-4 mg·(mg·h)-1,厌氧氨氧化菌消耗NO-2-N与NJ 4-N之比为1.311;采用分子生物学方法从EGSB反应器颗粒污泥中提取细菌总DNA,经纯化、特异引物PCR扩增、克隆、测序等过程,得到厌氧氨氧化菌部分16S rDNA序列;通过系统发育树分析可以发现,在EGSB反应器中富集得到的厌氧氨氧化菌种(anaerobic ammonium-oxidizing Planctomycete cquenviron-1)与Candidatus"Anammoxoglobus propionicus"和Candidatus"Jettenia asiatica"同属,arnaerobic ammonium-oxidizing Planctomycete cquenviron-1与其他厌氧氨氧化菌基因序列的同源性最大为93%.结果表明,前期EGSB反应器富集得到了一种新型厌氧氨氧化菌,该菌株命名为anaerobic ammonium-oxidizing Planctomycete cquenviron-1.     

Fetal akinesia/hypokinesia sequence: Prenatal diagnosis and intra-familial variability

Intrauterine fetal movement plays a key role in normal embryonic and fetal development (Moessinger, 1983). When movement is absent or decreased, abnormal development takes place which can be appreciated in newborns and/or fetuses with the fetal akinesia/ hypokinesia sequence. This sequence is caused by a number of heterogeneous entities which result in decreased fetal movements by the action of intrinsic or extrinsic factors. Prenatal diagnosis of the akinesia/hypokinesia sequence may be possible during the second trimester through the use of real-time ultrasonographic evaluation of fetal movement. We report a family with three consecutive affected pregnancies in which the prenatal presentation of this sequence varied. Based on the phenotypic findings of the three affected fetuses, we believe that although they superficially resemble those features found in the New–Laxova syndrome, they are probably affected with a distinctly different lethal form of akinesia/ hypokinesia transmitted in an autosomal recessive fashion.     

Oligohydramnios sequence in a live-born infant following chorionic villus sampling

We describe an infant born at 29 weeks' gestation with oligohydramnios sequence due to amniotic fluid leakage following chorionic villus sampling at 12 weeks. To our knowledge, this is the first such report.     

时数分离残差模型及在尾矿坝渗流预测中的应用

对于非等时序列的时数分离可以建立模型，但这种模型误差分析较困难。本文在残差GM(1，1)模型的基础上，建立了时数分离残差模型，对误差进行修正。应用这种模型分析了德兴铜矿1#尾矿坝的渗流趋势，结果表明，模型能够大大提高预测精度，满足工程预测的需要。