有关"致癌保鲜膜"问题的探讨

食品保鲜膜应用广泛,影响面大,"致癌保鲜膜"问题在我国掀起轩然大波;介绍食品保鲜膜的主要材质:聚乙烯(PE)、聚氯乙烯(PVC)、聚偏二氯乙烯(PVDC);分析哪些保鲜膜不安全;增塑剂DEHA是否致癌物,为什么有比较安全的PE保鲜膜,商家还要使用存在安全隐患的PVC保鲜膜;为什么有其他合法增塑剂不用,还要用违反国标的DEHA;不加增塑剂的保鲜膜是否绝对安全;保鲜膜能否放在微波炉里加热;有人不敢用保鲜膜,改用塑料袋、微波炉塑料容器了,是否保险.     

东莞市大岭山镇:打造现代生态新城创建全国环境优美乡镇

东临风光迤逦的松山湖,北靠同沙自然保护区,西南依大岭山森林公园,倚山傍湖,生成了大岭山镇的天生丽质.近年来,大岭山镇委、镇政府将建设"依山傍湖的现代生态新城"作为新时期战略目标,在"创建省卫生镇"等一系列工作上,获得喜人成绩.     

打破僵局

"我们拔了18吨,仍不见动静,请领导拿意见."4月13日,当河南油田井下作业二部副经理靳水生和工艺人员赶到L1256井场时,201修井队技术员范红禅立即向他们汇报拔钻解卡情况. "好,再拔拔看!"听到指令,司机汪佳柱启动30吨斜井作业机,一手扶离合器手柄,一手握刹把,脚踩油门,两眼紧盯指挥手势.作业机吼叫着,掐着油管的"脖子"使劲往上拽,那架势如同一场拔河比赛.压力器指针指向了18吨,油管还是一动不动.     

中俄界河黑龙江沿岸地区自然保护区建设和管理研究

随着生产力水平的不断提高和世界经济一体化趋势的快速发展,国际河流已成为有关国家开发的热点,国际河流的生态保护与生态安全是国家维护自身生态安全的前沿.界河--黑龙江流域可持续发展,对边境地区的稳定.防止流域生态退化和保护黑龙江流域森林、黑土地、湿地等资源具有重要意义.界河沿岸地区的自然保护区在保护该地区的生态环境,生物多样性、生态系统功能和国土安全方面起到了非常重要的作用.文章介绍了界河沿岸地区自然保护区的发展状况以及数量、面积、类型、分布和管理等现状,分析了制约自然保护区发展的主要因素提出了因地制宜的建设该地区自然保护区的有效措施及发展方向.     

两种有机磷农药对缢蛏(Sinonovacula constricta)鳃超微结构的影响

在实验室模拟缢蛏生长环境,研究结构、性质不同的两种典型有机磷农药(OPs)乐果和三唑磷对滩涂养殖生物缢蛏的毒性效应,通过电镜观察乐果和三唑磷对缢蛏鳃超微结构的影响.结果发现:乐果和三唑磷对缢蛏鳃超微结构的影响主要表现在对细胞核和各种细胞器(如线粒体、内质网、高尔基体)的伤害.主要病变为:细胞核变形,核膜凸起或凹陷,染色质发生凝聚或边缘化;线粒体肿大,双层膜溶解,内嵴部分消失;个别线粒体内嵴完全瓦解,形成电子透明区;粗面内质网水肿,核糖体部分脱落,片层结构间距增大;高尔基膜囊水肿,膜溶解,高尔基小泡破裂消失.本研究为了解不同OPs对缢蛏的毒性效应提供了病理形态学证据,为预测OPs对近海海洋生物及人类健康的影响提供有力的证据,为规范OPs的应用、制定海洋环境质量标准提供了部分基础理论依据.     

天津快速的经济发展造成的环境问题及具对策

直面冷峻的环境现状,每一个有理性与责任感的公民无不忧心如焚.蔽日的烟云、腥臭的污河、毒化的农田和振聋发聩的噪音一刻不歇地疯狂考验和鞭笞着人们从心灵到生理的忍耐极限.本文使用大量详实的数据还原出天津环保的真相,社会各界的高度关注、积极参与和成效卓著的努力让我们对天津山清水秀的明日充满了期待.     

中国水域中华白海豚种群分布现状与保护

中华白海豚是国家Ⅰ级重点保护野生动物,在中国主要分布于广西、海南、广东、香港、澳门、福建、台湾西部、浙江沿岸,向北达东海北部长江口,黄海北部辽宁沿岸偶有发现.自南向北形成各自的地方种群,相邻种群间可能有基因交流.渔业时有误捕,沿岸屡有搁浅,各栖息地段的种群数量呈现减少趋势.资源减少的主要原因是受人类活动加剧的影响,以及生态环境不断恶化,威胁着本种的生存.为此建立中华白海豚自然保护区是最有效的保护措施之一,但亟待采取有效的管理措施和健全管理机制,加强中华白海豚的资源保护.     

上海市交通干道空气中挥发性有机物冬季污染特征研究

2004年冬季对上海市交通干道附近空气中的挥发性有机物进行了连续6天的监测.采用GC-MS定性检出28种物质,芳香烃和烷烃分别占32%和25%.在检出物中有8种属于美国EPA优先控制的有毒有害物质.GC-FID定量表明,芳香烃中含量最高的是苯系物(BTEX)苯、甲苯、乙苯、二甲苯,其中甲苯浓度最高.苯系物的浓度与一氧化碳和二氧化氮的良好相关性说明苯系物的来源与机动车尾气密切相关,而且都受风速和车流量的影响.     

浅析电子政务信息的定位及实践

2006年起,广西壮族自治区地震局把做好政务信息工作摆上了重要议事日程,安排了专人负责,落实了措施,落实了专项经费,政务信息工作发生了质的飞跃.特别是信息管理员制度和激励机制从根本上改观了政务信息往日的面貌.本文介绍了广西壮族自治区地震局电子政务信息工作在事业发展中的定位、主要做法、成效和经验,意在抛砖引玉,加强学习和交流.     

电石渣综合利用研究进展

详细介绍了电石渣在生产建材,治理环境污染,生产化工产品等方面的利用,并对它们在处理效果,创造的经济效益及实际应用过程中遇到的问题进行了分析.提出了一种处理电石渣的有效方法--生产具备高附加值的纳米碳酸钙,在实现经济效益的同时,还能创造良好的环境效益及社会效益.     

Exploration of relationships between phytoplankton biomass and related environmental variables using multivariate statistic analysis in a eutrophic shallow lake： A S-year study

Understanding the process of the changing phytoplankton patterns can be particularly useful in water quality improvement and management decisions. However, it is generally not easy to illustrate the interactions between phytoplankton biomass and related environmental variables given their high spatial and temporal heterogeneity. To elucidate relationships between them, in a eutrophic shallow lake, Taihu Lake, relative long-term data set of biotic and abiotic parameters of water quality in the lake were conducted using multivariate statistical analysis within seasonal periodicity. The results indicate that water temperature and total phosphorus （TP） played governing roles in phytoplankton dynamics in most seasons （i.e. temperature in winter, spring and summer; TP in spring, summer and autumn）; COD （chemical oxygen demand） and BOD （biological oxygen demand） presented significant positive relationships with phytoplankton biomass in spring, summer and autumn. However, a complex interplay was found between phytoplankton biomass and nitrogen considering significant positive relationships occurring between them in spring and autumn, and conversely negative ones in summer. As the predatory factor, zooplankton presented significant grazing-pressure on phytoplankton biomass during summer in view of negative relationship between them in the season. Significant feedback effects of phytoplankton development were identified in summer and autumn in view that significant relationships were obser,qed between phytoplankton biomass and pH, Trans （transparency of water） and DO. The results indicate that interactions between phyto：plankton biomass and related environmental variables are highly sensitive to seasonal periodicity, which improves understanding of different roles of biotic and abiotic variables upon phytoplankton variability, and hence, advances management methods for eutrophic lakes.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

基于电子鼻土壤与地下水污染修复现场TVOC和恶臭的评估

根据上海某土壤与地下水污染修复现场情况,应用自主研发的电子鼻系统(iSA-M1)分别对未修复及修复过程中的土壤和地下水、修复场地上空及周边空气中的VOCs和恶臭类气体进行检测.结合前期研究所得TPI和OPI公式,求得各点的值,并将其用图表示.结果表明:①修复后TVOC和恶臭的浓度总体呈下降趋势;②在土壤和地下水修复过程中,VOCs和恶臭的挥发受气象要素和作业的影响,其浓度在总体下降的过程中伴随着阶段性上升现象;③结合GIS技术,电子鼻能初步用于评估土壤和地下水修复现场造成的空间污染情况及对周围居民产生的影响.但造成影响程度的具体细化分级还需要进一步研究.     

厌氧氨氧化过程中COD及pH与基质浓度之间的关系

分析了上向流厌氧氨氧化生物滤池中氮素化合物浓度、COD和pH变化规律以及ANAMMOX活性和生物量的分布规律,利用数理统计的方法研究了厌氧氨氧化过程中COD和pH与氮素基质浓度之间的关系.结果表明,溶解氧和氮负荷的共同作用使得ANAMMOX活性和生物量的分布沿滤层深度呈"山脊"状不均匀分布;异养反硝化的存在和H+的消耗使得厌氧氨氧化过程中COD和pH分别呈降低和升高趋势;100 mg/L以下的有机物浓度对厌氧氨氧化菌的影响不大,且COD和pH与基质NH4+-N浓度之间呈良好的线性相关关系.本试验中COD-NH4+-N和pH-NH4+-N拟合直线的斜率分别为1.113 8±0.052 2和-0.111 3±0.001 2,置信度为95%,平均相关系数R2分别为0.982 3和0.985 0.     

污泥超高温好氧发酵去除氟喹诺酮类抗生素及其降解产物

对比分析了污泥传统高温好氧发酵(TC)和超高温好氧发酵(HTC)对诺氟沙星(NOR)、氧氟沙星(OFL)及其降解产物的去除性能.结果表明,超高温好氧与高温好氧发酵25d时NOR去除率分别为91.8％,92.1％,产物诺氟沙星脱乙基(NORP)残留含量分别为628,668μg/kg;OFL去除率分别为92.1％、88.1...     

Characteristics of indoor/outdoor PM2.5 and elemental components in generic urban, roadside and industrial plant areas of Guangzhou City, China

Quantitative information on mass concentrations and other characteristics, such as spatial distribution, seasonal variation, indoor/outdoor （I/O） ratio, correlations and sources, of indoor and outdoor PM2.5 and elemental components in Guangzhou City were provided. Mass concentration of PM2.5 and elemental components were determined by standard weight method and proton-induced X-ray emission （PIXE） method. 18 elements were detected, the results showed positive results. Average indoor and outdoor PM2.5 concentrations in nine sites were in the range of 67.7-74.5μg/m^3 for summer period, and 109.9-123.7 μg/m^3 for winter period, respectively. The sum of 18 elements average concentrations were 5362.6-5533.4 ng/m^3 for summer period, and 8416.8-8900.6 ng/m^3 for winter period, respectively. Average concentrations of PM2.5 and element components showed obvious spatial characteristic, that the concentrations in roadside area and in industrial plant area were higher than those in generic urban area. An obvious seasonal variation characteristic was found for PM2.5 and elemental components, that the concentrations in winter were higher than that in summer. The I/O ratio of PM2.5 and some elemental components presented larger than 1 sometimes. According to indoor/outdoor correlation of PM2.5 and element concentrations, it was found that there were often good relationships between indoor and outdoor concentrations. Enrichment factors were calculated to evaluate anthropogenic versus natural elements sources.     

Nitrogen cycling of atmosphere-plant-soil system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain, Northeast China

The nitrogen (N) distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland (TMCW) and marsh meadow Calamagrostis angustifolia wetland (MMCW) in the Sanjiang plain were studied by a compartment model. The results showed that the N wet deposition amount was 0.757 gN/(m2·a), and total inorganic N (TIN) was the main body (0.640 gN/(m2·a)). The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m2, respectively. In plant subsystem, the N was mainly stored in root and litter. Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively. The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/(m2·a) and the values of aboveground were 11.31 and 6.08 gN/(m2·a), the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/(m2·a), the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/(m2·a), the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/(m2·a), the translocation amounts from root to soil were 14.90 and 13.17 gN/(m2·a), and the soil (0-15cm) N net mineralization amounts were 1.94 and 0.55 gN/(m2·a), respectively. The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N, and the status might induce the degradation of C. angustifolia wetland.     

北京市夏季O3、 NOx等污染物“周末效应”研究

采用了2000-06-25~2000-07-07以及2000-07-26~2000-08-22在北京325 m气象塔观测平台观测到的O3、NOx(NO和NO2)、CO和SO2数据,分析了周末与工作日O3、NOx、NO、NO2、CO和SO2浓度变化的差异及成因.结果表明,除SO2之外,O3、NOx、NO、NO2和CO的周末浓度与对应工作日浓度相关性显著,均通过了显著性水平α=0.05的t检验,相关系数(R)依次为0.99、0.61、0.56、0.80和0.61.交通高峰时段(06:00~08:00)NOx和CO的周末浓度明显低于工作日浓度,该时段NOx和CO的周末浓度与工作日浓度的平均偏差分别为-28%和-9%.O3周末浓度与工作日浓度的回归系数为1.25±0.02.此外,周末O3的最大小时浓度值与最大8 h平均浓度值分别比工作日高23%和26%,表现出十分明显的"周末效应".     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.