Recent expansion led to the lack of genetic structure of Sargassum aquifolium populations in Southeast Asia

Phylogeographical study of the brown macroalga, Sargassum aquifolium using nuclear internal transcribed spacer 2, plastidal RuBisCo spacer, and mitochondrial cytochrome oxidase subunit-III revealed the populations in Southeast Asia to be homogeneous. On the other hand, genetic differences were detected between populations from Southeast Asia and western Pacific Islands/Guam, suggesting the presence of genetic break between these regions. This further suggests that populations of S. aquifolium may have survived east of Sunda Shelf during the Last Glacial Maximum and recent recolonization led to homogeneity of the populations in the Sunda Shelf region. Recolonization could be facilitated by year-round reproduction of the populations and dispersal of germlings on floating thalli by coastal currents. Restricted current flow across Maluku Sea and directional equatorial current flows could have isolated the Pacific Island and Guam populations from those of Southeast Asia. Our results support the presence of multiple refugia as the source of different lineages of S. aquifolium populations with a lack of secondary contact in the post-glacial dispersal between Southeast Asia and western Pacific as the mechanisms behind the phylogeographical patterns observed.     

污泥土地利用对草坪草及土壤的影响

以沈阳北部污水处理厂污泥为研究对象,开展了污泥土地利用对草坪草及土壤环境影响的研究.结果表明,污泥土地利用可提高土壤养分含量特别是土壤中有机质含量;使草坪草获得了良好的生长响应,草坪草生物量增加,绿期延长;使土壤重金属含量有所增加,Cd元素含量超过土壤环境质量二级标准,而土壤Pb、Cu、Zn元素含量均未超过土壤环境质量二级标准;早熟禾对Pb具有良好的吸收富集能力,污泥在25、30、60t·hm^-2低施入量时,结缕草对Cd、Cu、Zn具有良好的吸收富集能力.     

北京大气PM2.5中微量元素的浓度变化特征与来源

为了解北京大气细粒子中微量元素的污染水平和来源,在车公庄和清华园进行了连续1年、每周1次的PM_2.5采样和全样品分析.微量元素浓度的周变化大,尤以冬季为甚,相邻2周最大相差达1.6倍;但除冬季的平均浓度较高之外,其季节变化并不显著.微量元素的富集因子在春季最低,反映了频繁发生的沙尘天气的影响.Se、Br和Pb的浓度比来自于北京A层土壤中的含量要高出约1000～8000倍,表明它们主要来自于人为污染.其中Se的富集度最高,反映了北京细粒子来自于燃煤污染的特征.Pb的年均浓度(0.31μg·m^-3)虽然未超过WHO的年均标准,但与洛杉矶和布里斯班相比处于较高的水平;与Br、Se的比较分析表明,燃煤可能是Pb除机动车排放之外的另一个重要来源.     

Monitoring the toxicity of phenolic chemicals to activated sludge using a novel optical scanning respirometer.

This paper reports the development of optical scanning respirometer for determining the toxicity of chemicals to activated sludge. The respirometer is used to measure the dissolved oxygen concentration by monitoring the luminescence intensity of ruthenium dye immobilized in a polymer film in contact with the wastewater sample. The intensity is related to the extent of oxygen quenching of luminescence. The toxicity of chemicals can be evaluated by measuring the inhibition on respiration rate of microorganism using the scanning respirometer. The IC50 values (concentration of a chemical that exhibits 50% respiration inhibition) of various phenolic chemicals in activated sludge were determined. The performance of this method is compared with other toxicity methods. The experimental results indicate that the reproducibility and sensitivity of this respirometer are reasonably good.     

广州街道空气中挥发烃类特征和来源分析

采用固相吸附－热脱附－色谱／质谱检测器联用的方法分析了广州市街道空气中的发挥有机物。样品采自广州市区街道的３２个采样点,主要探讨了其中单环芳烃和正构烷烃的特征和可能来源;选取１３种烃类化合物进行进一步的因子分析,结果表明,这些挥发烃类可能主要来自汽油机车、工业和柴油机车的排放。多元线性回归分析表明３种源对所选挥发烃类的平均贡献分别为６４％、２３％和１３％。     

粤港澳地区大气中有机污染物初步研究

用Ｔｅｋｍａｒ多填层吸附管连接ＴＭＰ－１５００空气采样采集ＶＯＣｓ样,然后在Ｔｅｋｍａｒ６０３２／３０００吹扫捕集系统与ＧＣ／ＭＳＤ联用仪上分析,用ＴＨ－１０００Ｌ型大量采样器收集ＴＳＰ气溶胶样,ＴＳＰ滤膜经抽提分离后,烷径和芳烃进行ＧＣ／ＭＳＤ分析,了广州,香港和澳门地区大气 有机物和气溶胶可溶有机物的与成因。     

An empirical survey of the benefits of implementing pay for safety scheme (PFSS) in the Hong Kong construction industry

Introduction

The Government of the Hong Kong Special Administrative Region (SAR) has implemented different safety initiatives to improve the safety performance of the construction industry over the past decades. The Pay for Safety Scheme (PFSS), which is one of the effective safety measures launched by the government in 1996, has been widely adopted in the public works contracts. Both the accident rate and fatality rate of public sector projects have decreased noticeably over this period.

Method

This paper aims to review the current state of application of PFSS in Hong Kong, and attempts to identify and analyze the perceived benefits of PFSS in construction via an industry-wide empirical questionnaire survey. A total of 145 project participants who have gained abundant handson experience with the PFSS construction projects were requested to complete a survey questionnaire to indicate the relative importance of those benefits identified in relation to PFSS. The perceived benefits were measured and ranked from the perspectives of the client and contractor for crosscomparison.

Results

The survey findings suggested the most significant benefits derived from adopting PFSS were: (a) Increased safety training; (b) Enhanced safety awareness; (c) Encouragement of developing safety management system; and (d) Improved safety commitment. A wider application of PFSS should be advocated so as to achieve better safety performance within the construction industry.

Impact on Industry

It is recommended that a similar scheme to the PFSS currently adopted in Hong Kong may be developed for implementation in other regions or countries for international comparisons.     

引入路径权重蚁群算法在应急救援中的应用

规划最优路径是应急救援时一项很重要的工作。在基本蚁群系统模型的基础上,基于层次分析法解算出路径权重矩阵,并将其引入状态转移规则,这样求出的最优路径不只是考虑路径距离,而且考虑了道路实际状况。仿真实验结果表明,引入路径权重后的自适应蚁群算法能根据实际路况权重矩阵规划出更合理的救援路径,缩短了救援时间。     

烟酰胺降解菌的筛选及其降解特性

采用HPLC对某烟酰胺生产废水的主要成分进行分析,并模拟废水中的主要成分烟酰胺(nicotinamide)的浓度,对以烟酰胺为唯一碳源配制的培养基进行降解实验,获得有较佳降解率和生长能力的菌株YSI-1和YSI-2.结果表明,YSI菌株的混合菌降解效果优于单株菌,混合菌在初始OD600值为0.4,pH为7.0时,对浓度为2000 mg/L的烟酰胺降解2 d的降解率可达32.8%.延长处理时间或提高菌种的初始OD600值,烟酰胺的去除率均有较大的增加.     

公众环境权益不可侵犯

八月,环保电波划过南粤天空。 “各位听众,上午好,我是广东省环保局局长李清,很高兴能有机会在‘民声热线’栏目中与大家交流……”8月8日上午11：30分,广东省环保局局长李清上线“民声热线”,在广东省电台直播间亲自解答群众来电和短信提问。这是广东省环保局首次参加由广东省政府纠风办、广东省电台联合主办的“民声热线”上线直播节目。