6种苯系物对虾夷扇贝的生殖毒性作用

采用半静水式毒性试验,研究了6种苯系物(苯、甲苯、乙基苯、邻–二甲苯、间–二甲苯、对–二甲苯)对虾夷扇贝的生殖毒性作用。在水温(16±0.5)℃、盐度30.0、p H 8.0条件下,用0.5、2.5、12.5 mg·L-1的苯、甲苯、乙基苯、邻–二甲苯、间–二甲苯、对–二甲苯处理虾夷扇贝的精子、胚胎和幼体,观察6种苯系物对虾夷扇贝的精子活力、卵子受精率、胚胎延滞率、胚胎畸形率、孵化率、幼体畸形率的影响。同时通过透射电镜观察6种苯系物(2.5 mg·L-1)对虾夷扇贝精子超微结构的损伤作用。结果发现:不同浓度苯系物处理组与对照组(0.0 mg·L-1)相比,虾夷扇贝精子的运动时间、卵子受精率及胚胎孵化率显著降低;胚胎发育延滞率、胚胎畸形率和幼体畸形率显著增加为并与处理浓度之间存在显著的剂量—效应关系。以上结果表明实验浓度下,6种苯系物对虾夷扇贝具有较强的胚胎毒性和生殖毒性作用。通过电镜切片发现,2.5 mg·L-1的苯、甲苯、乙基苯、邻–二甲苯、间–二甲苯、对–二甲苯导致虾夷扇贝精子超微结构损伤,表现为:精子质膜断裂、部分溶解,线粒体质膜和内嵴断裂、部分溶解。苯系物对虾夷扇贝精子超微结构的损伤可能是影响其精子活力和降低卵子受精率的主要原因之一。上述结果为苯系物对海洋贝类的生殖毒性评价提供基础数据。     

A model of 90Sr distribution in the sea near Daya Bay Nuclear Power Plant in China

The impact on the environment ofradionuclide release from nuclear power plants has attracted increased attention, especially after the accident at Fukushima Daiichi Nuclear Power Plant in Japan. Based on the mechanisms of adsorption/desorption at solid/liquid interfaces and a surface micromorphology model of sediments, a theoretical expression of the distribution coefficient Kd is derived. This coefficient has significant effects on the distribution of radionuclide in seawater, suspended sediment and seabed sediment. Kd is then used to simulate ^90Sr transport in the sea near the Daya Bay Nuclear Power Plant. The simulation results are compared with field measurements of tidal level, current velocity, suspended sediment concentration and ^90Sr concentrations in the same period. Overall, the simulated results agree well with the field measured data. Thus, the derived expression for Ka is capable of interpreting realistic adsorption/desorption processes. What＇s more, conclusion is drawn that about 40% ^90Sr released by Daya Bay Nuclear Power Plant will be adsorbed by suspended sediment and 20% by seabed sediment, only about 40% ^90St will remain in the sea near Daya Bay Nuclear Power Plant in South China Sea.     

Neighborhood form and CO2 emission: evidence from 23 neighborhoods in Jinan, China

To understand the household C02 emission level in China, as well as how much the neighborhoods＇ socio-economic or design factors could influence the CO2 emission, 23 neighborhoods in Jinan were investigated in 2009 and 2010. These neighborhoods fall into four different types： superblock, enclave, grid and traditional. The household CO2 emission includes sources of both in- home energy use and passenger transportation. The average CO2 emission per household is 7.66 t.a^-1, including 6.87 t in-home operational emission and 792 kg transportation emission. The household CO2 emission by neighborhood categories is 10.97, 5.65, 6.49, 5.40 t-household-1. a-1 for superblock, enclave, grid and tradi- tional respectively. Superblock has the highest average emission and also the highest percent （more than 25%） of transportation emission among four different types of neighborhoods. The residential CO2 emission of superb- lock neighborhoods in Jinan has already reached the level in developed countries nearly ten years ago. It is predictable that more superblock neighborhoods would be built in China with the fast urbanization. How to avoid the rapid household CO2 emission growth in the future would be a systematic issue. The study also found that in addition to income and apartment area, household density, land use mix and accessibility to public transportation are three primary factors which have significant impacts on CO2 emission. High density, mixed land use and convenient accessibility to public transportation tend to reduce household CO2 emission.     

Investigation on sampling artifacts of particle associated PAHs using ozone denuder systems

Polycyclic aromatic hydrocarbons （PAHs） are complex organic compounds which are identified as significant carcinogenic to human health. PAHs （mainly in particle phase） are susceptible to atmospheric oxidant gases, especially ozone, nitrogen oxides （NOx）, hydroxyl radical （OH）, and could be degraded on filters during sampling process, leading to an underestimation of ambient PAH concentrations. The goal of this work was to investigate particle associated PAHs sampling artifacts caused by ozone in summer of Beijing. Comparative sampling systems were operated simultaneously during the whole campaign, one with activated carbon ozone denuder, the other being set as conventional sampling system. Activated carbon denuder was testified to be highly efficient to eliminate ozone from air stream. In general, nine particle-bound PAHs observed from conventional sampler were all lower than those from ozone denuder system. The total PAHs （particle phase） concentration was averagely underestimated by 35.9% in conventional sampling procedure. Benzo[a]pyrene （BaP） had the highest percentage of mass loss. founded to have influences Ambient temperature was on PAHs sampling artifacts. High temperature can increase loss of particle associated PAHs during sampling.     

安全生产技术支撑体系建立的研究

为了解决安全生产事故预防和事故处理方面的技术保障问题,加强对安全生产的监督和监察,必须建立各级安全生产技术支撑体系专业中心。建设的目的是围绕加强灾害事故的鉴定分析、灾害预防、安全技术的研究以及直接为国家各级安全生产监管监察机构履行职责提供技术支撑等。就省级企事业中非矿行业的安全生产技术支撑体系的建立作了初步研究,提出自己的观点,为各级工业安全生产技术支撑体系中心的建立提供可参考的依据。     

塔河油田一号联合站污水处理试验研究

塔河油田一号联合站(塔一联)稠油污水具有粘度大、油水密度差小、乳化严重等特点,它的回用与外排具有一定的难度.通过实验室和现场试验研制开发的破乳剂和混凝剂,强化了除油效果,减轻了过滤系统的负荷,处理污水达到了注水水质指标.     

草原荒漠化的历史反思

内蒙古草原曾经拥有十分美好的过去,但如今取而代之的是草原的大面积减少和日趋严重的荒漠化。对此,虽有不少草原学家、生态学家、经济学家从多个角度进行了多年研究,但自然科学与人文社会科学相互交叉的跨学科研究成果并不多见。本文拟从内蒙古草原变迁的历史反思人手,揭示其荒漠化形成及加剧过程中的文化因素,并提出其治理中的一些问题,对实现草原牧区可持续发展起一些作用。     

名山大川的形成

在锦秀中华众多的名胜景观中,名山大川占据着主要的地位。我国的名山很多,品类繁多,规模小一。     

地震带上的建筑物能抗震吗?

近几年来,我国一直处在地震活动的高潮期。据统计,我国大陆有41%的国土属于地震基本烈度Ⅶ度以上高烈度区。     

名山大川的形成(五)

峨眉山景物清幽秀丽,山势嵯峨峭奇,历来有“峨眉天下秀”的美誉,是我国重要的名山,更是我国佛家四大名山之一,