Bacterial diversity in activated sludge from a consecutively aerated submerged membrane bioreactor treating domestic wastewater

The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphism (RFLP). Of the screened clones, almost full-length 16S rDNA sequences of 64 clones were sequenced. Phylogenetic tree was constructed with a database containing clone sequences from this study and bacterial rDNA sequences from NCBI for identification purposes. The 90.6% of the clones were a?l...     

吉林省主要河流指定标准功能可达性分析

根据吉林省地方标准规定的河流水域功能类别和1995年水质监测结果,采用水质单项标准指数法,对吉林省主要河流34个国控和省控监测断面的单项指标、全指标、有机污染型指标和重金属污染型指标进行了功能评价。结果表明,仅有6个监测断面满足指定的标准功能要求,符合率仅为17.6％,主要超标污染物是COD_Mn和挥发酚。以COD为控制指标,根据逆推法的河流水环境容量模式,计算了污水达标排放情况下的污水允许排放量,从而对河流控制断面指定的标准功能进行了可达性分析。结果表明,污水达标排放时,河流流量较大、污径比较小的河流可达到指定标准功能要求;而枯水期流量较小、污径比较大的河流很难达到,应实施重点污染物的排放总量控制制度。     

微囊藻毒素-RR对烟草细胞活力及营养生理的影响

采用0.1,1.0,10.0μg/mL的微囊藻毒素-RR(MC-RR)处理烟草BY-2悬浮细胞,测定了细胞活力、细胞内蛋白质含量、可溶性糖含量、硝态氮含量及总磷含量,并且检测了酸性磷酸酶(ACP)的活力变化情况.结果表明,中、高浓度毒素处理细胞2d后,细胞活力及蛋白质含量与对照相比均显著下降.高浓度MC-RR处理降低了胞内可溶性糖的含量,暴露2d后仅为对照的45.57%;低浓度MC-RR处理在后期增加了胞内可溶性糖含量.高浓度毒素处理细胞4d后,细胞内硝态氮含量显著低于对照;中、低浓度毒素处理细胞7d后降低了胞内硝态氮含量.3组毒素处理均降低了胞内总磷含量,到实验结束时,低、中、高浓度处理组的胞内磷含量分别为对照的74.98%、76.47%和84.00%.3组处理组ACP活力与对照相比呈现先降低后升高的趋势.     

城市湖泊水环境整治对改善水质的影响:以蠡湖近30年水质变化为例

自"十五"以来,为改善水质,我国许多城市湖泊均先后采取了水环境治理措施.为了解这些措施对富营养化城市湖泊水质改善成效,根据中国科学院太湖湖泊生态系统研究站对蠡湖的长期监测数据和本课题组2017年对蠡湖的两次调查结果进行汇总分析,探讨了无锡蠡湖综合整治前后近30年来水环境质量变化情况.结果表明:①TN、TP、高锰酸盐指数和Chl-a等水质指标的浓度从20世纪90年代初开始呈现快速上升的趋势,1997～2003年间处于最差状态,2003年经过综合整治后呈现逐年递减趋势,但近两年略有反弹;水体透明度整治前后无明显改善.②从季节上看,综合整治之前,水质波动较大;综合整治之后,蠡湖各项指标出现显著差异,冬季水质明显好于夏季.③从区域上来看,蠡湖西部水质明显优于东部湖区.综合其他城市湖泊治理情况,研究表明水环境治理可以改善湖泊水质,但在水质改善后需要恢复草型生态系统,推进以生物调控为主的生态修复,逐步提升物种多样性,真正恢复湖泊生态系统服务功能.     

Responses of protists with different feeding habits to the changes of activated sludge conditions: A study based on biomass data

Changes of protists, which were categorized into different functional groups primarily according to their feeding habits, in two full-scale municipal wastewater treatment systems experiencing sludge bulking were investigated over a period of 14 months. Protist biomass represented 3.7% to 5.2% of total biomass on average under normal sludge conditions, and the percentage increased significantly (p < 0.05) under sludge bulking conditions. The biomass of Chilodonella spp., capable of eating filamentous bacteria, tended to decrease in both systems when sludge bulking occurred, showing that the abnormal growth of filamentous bacteria did not lead to a biomass bloom of this group of protists. On the other hand, the bactivorous protists represented more than 96% of total protist biomass, and the biomass of this group, particularly the attached ciliates, increased significantly (p < 0.05) when sludge bulking occurred. The significant increase of the attached ciliates may have possibly facilitated the growth of filamentous bacteria through selectively preying on non-filamentous bacteria and further exacerbated sludge bulking. The redundancy analysis and correlation analysis results showed that the biomass changes of the attached ciliates were primarily related to the sludge volume index and to some extent related to five-day biochemical oxygen demand loading and hydraulic retention time.     

Positive affectivity neutralizes transformational leadership's influence on creative performance and organizational citizenship behaviors

This study uses an interactionist approach to examine the moderating effect of follower trait positive affectivity (trait PA) on the relation between transformational leadership and both follower creative performance and organizational citizenship behaviors (OCB). On the basis of responses from 212 employees and their direct supervisors from the research and development department of a company in Mainland China, results support the hypothesized moderation effect. Specifically, the positive influence of transformational leadership on creative performance was significantly reduced for followers who were higher on trait PA (ΔR² = .02, p < .05). The same pattern, in which followers' trait PA appeared to substitute for the influence of transformational leadership, generalized to the outcome of follower OCB as well (ΔR² = .04, p < .01). We discussed theoretical and practical implications of these findings. Copyright © 2012 John Wiley & Sons, Ltd.     

Acoustic detection technology for gas pipeline leakage

Gas leakage from pipeline leads to significant environmental damages and industrial hazards, so small leakage detection for gas pipeline is essential to avoid these serious leakages. However, because of the high frequency component of leakage signal attenuates quickly, traditional detection method which inspects pressure or vibration signal has problem to get effective information from leakage signal. So, a novel detection method based on acoustic wave is proposed. This paper, firstly, researches on the phonation principle of pipeline leakage and the characteristic of sound source, and simulates the leakage acoustic field on the basis of aero acoustics. Secondly, using Wavelet Packet Transform method and Fuzzy Support Vector Machine pattern classification, the laboratory testing for identifying acoustic signal of gas pipeline leakage is presented. Finally, the field application demonstrates that the detection system could identify small gas leakage effectively and avoids false-alarms which caused by running conditions with a good prospect.     

人体装甲测试用模拟破片的应用与发展

模拟破片是人体装甲防弹性能测试评价的主要试验弹体.本文对人体装甲和模拟破片进行了阐释,分析了模拟破片的应用背景,对国内外现状进行了对比分析,对标准模拟破片的确定以及爆炸破片的发展进行了探讨,提出了开展新型模拟破片及其测试技术研究的重要意义.     

易燃易爆场所的静电防护

本文分析了易燃易爆场所的静电危害,提出了从"人、机、环、管"四个方面对易燃易爆场所进行静电防护,介绍了相关的静电防护标准及技术要求,为易燃易爆场所的静电防护提供有益的参考。     

信息化在海外油气项目HSE管理中的应用

伴随着中国石油企业走出去的步伐不断加快,海外油气项目的规模迅速扩大,相较于国内而言,海外油气项目面临的环境更加复杂,HSE管理难度更大。探索一种科学、高效并且符合现代化管理要求的先进管理手段,与企业的HSE管理有机融合,从而确保企业HSE管理体系良好运行,对于企业具有重要意义。中国某石油企业海外项目（A公司）在此方面进行了大量、有益的实践,其将自身的信息管理系统与HSE体系有机融合,从而实现了HSE管理的信息化。选取A公司的事故预防应急系统作重点介绍,将A公司的事故预防管理与传统事故预防管理进行对比,同时将A公司的应急管理与传统应急管理进行对比,最后提出了针对HSE管理信息化的思考,以期对石油企业海外项目的HSE管理提供帮助。