Ⅱ824-2综放工作面瓦斯综合治理试验研究

通过对淮北芦岭矿Ⅱ824-2综放工作面瓦斯综合治理的试验研究,摸索出了高瓦斯综放工作面瓦斯治理的有效方法,取得了较好的瓦斯抽放和通风排放效果.     

高位铁皮水箱供水质量及影响因素

我们于１９９５年３月￣４月调查了武汉市高位铁皮水箱的供水质量。结果表明：高层住宅水箱近年虽曾清洗消毒，但高层用户龙头水及水箱水中游离性全氯未达标比例较大，分别为７３．３％和６６．７％。个别底层住户水样中铁超标。高位水箱水样中细菌总数超标比例为２０％。反映了高层住宅二次供水中在水的输送、贮存过程中有二次污染存在。经水样监测指标相关性和灰色关联性分析，认为游离性余氯可作为常规监测高层住宅二次供水质量的     

The role of turbidity as a constraint on predator-prey interactions in aquatic environments

Many of the world's most productive aquatic ecosystems usually contain turbid water. Paradoxically, many fish species that live in these habitats are also those that often rely on vision to detect their predators and their prey. For these fish, turbidity will reduce the distance at which predator-prey interactions occur, and there should be a reduction in the opportunity for behavioural modification to control the risk of predation. Under these conditions, we predict that most antipredator behaviour will become ineffective and that predator-prey interactions in turbid water will be primarily characterised by the direct effects of predator consumption of prey, rather than behavioural modification reducing the growth rates of prey. This hypothesis was tested in two laboratory experiments. The first experiment investigated how water turbidity, risk of predation, and their interaction affect habitat choice decisions by fathead minnows (Pimephales promelas). These data demonstrate that fathead minnows reduce their use of dangerous habitats, but that this effect is diminished in turbid water. A second experiment examined mortality patterns when these fish were preyed upon by yellow perch (Perca flavescens) in clear and turbid water. Absolute mortality rates were unaffected by visibility, but patterns of mortality were random in turbid water and skewed towards smaller individuals in clear water. Combined, these results support our hypothesis and suggest that the impact of predation risk will be reduced in turbid aquatic ecosystems. Received: 23 May 1996 / Accepted after revision: 18 November 1996     

Impingement losses of white perch at Hudson River power plants: Magnitude and biological significance

We performed a quantitative assessment of the impact of impingement at power plants on the Hudson River white perch population We estimated that impingement reduces the abundance of each white perch year class by at least 10% and probably by 15–20% or more after 2–3 years of vulnerability to power plants We attempted to detect effects of impingement on average year-class abundance of white perch from a time series of abundance indices derived from impingement data We found, however, that neither impingement collection rates observed at Hudson River power plants nor beach seine data provide a reliable index of year-class strength in white perch. Even if a reliable index were developed, natural fluctuations in year-class strength are great enough that a short-term monitoring program would be inadequate for detecting even a large reduction in average year-class strength. We performed a multipopulation analysis using simple food chain and food web models The results suggest that any long-term decline in white perch abundance caused by impingement should be accompanied by an increase in the abundance of one or more competing fish species and by an increase in the biomass of adult white perch relative to young-of-the-year.We conclude that 1) at present, assessments of population-level impact of impingement should focus on short-term effects, 2) research is needed to develop a reliable index of year-class strength for use in long-term monitoring programs, 3) identification and quantification of natural environmental factors influencing year-class strength are needed to improve our ability to predict and detect changes in abundance, and 4) it would be useful in designing monitoring programs to focus on detecting patterns of change among populations and age groups rather than solely on declines in abundance of individual populationsResearch sponsored by the Office of Nuclear Regulatory Research, US Nuclear Regulatory Commission under Interagency Agreement No. 40-550-75 with the US Department of Energy under Contract W-7405-eng-26 with Union Carbide Corporation. Publication No. 2030, Environmental Sciences Division, ORNL.     

SOME EFFECTS OF ACIDIFIED WATER ON THE EARLY DEVELOPMENT OF ROACH (Rutilus rutilus L.) AND PERCH (Perca fluviatilis L.)1

ABSTRACT. Fertilized eggs of perch (Perca fluviatilus L.) and roach (Rutilus rutilus L.) were reared at different pH values both in the field and in the laboratory. The results from the laboratory tests revealed that both species showed at least a 50% decrease in their hatching frequencies when reared at pH values below 5.6. At pH values below 4.6 both species studied show an almost complete lack of reproduction. The field studies with eggs from different lakes indicated that there might be an adaptation, manifesting itself as a higher frequency of hatching in water with a composition similar to that of the natural habitat. Field experiments also showed that the roach is more sensitive than perch to low pH values.     

Enzymatic and cellular level effects of nickel∗

The effects of Ni on hepatic enzymes of tilapia, viz. acid‐ and alkaline phosphatases, catalase and glucose‐6‐phosphatase, both under in vivo and in vitro conditions reflected the following tendencies. In vivo conditions indicated maximal increase in activity for acid phosphatase at 3.00 ppm, equivalent to 28.5%, followed by a slight decrease and increase thereafter. As for alkaline phosphatase, gradual increase in activity was observed with maximal activity at 9 ppm of Ni, equivalent to 16.8%. Catalase demonstrated similar tendencies with maximal activity at 9.0 ppm, equivalent to 101.2%. In the case of glucose‐6‐phosphatase, the tendency was the reverse with maximal inhibition at 9.00 ppm, i.e. 41.9%. In contrast to in vivo conditions, in vitro systems indicated that all investigated enzymes were inhibited in the region of 4–10% except for catalase which demonstrated a slight increase by 5–6% in activity between concentrations of 10–15 ppm of Ni but thereafter continuous inhibitory effects prevailed.

At cellular level, exposure of tilapia to a lethal dose of 9 ppm of Ni indicated not much of an adverse effect except for a slight depletion in fat and glycogen content. In the case of mitochondria, they were normal and a few large secondary lysosomes were observed. In relation to the cell membrane no dramatic change was detected.     

鳜鱼两种谷胱甘肽S-转移酶基因cDNA的克隆与分析

鳜鱼(Siniperca chuatsi)是我国著名的肉食性鱼类,容易成为环境毒素的富集体.论文从分子水平上分析了鳜鱼去毒过程中起关键作用的谷胱甘肽S-转移酶(GST)基因的结构及进化上的地位,采用RT-PCR及RACE法,分离、克隆得到了鳜鱼肝脏可溶性alpha型(GSTA)和rho型(GSTR)基因cDNA全序列.结果表明,鳜鱼肝脏GSTA、GSTR全长分别为1052bp、935bp,其中5′-UTR分别为118bp、55bp,3′-UTR分别为262bp、202bp,分别编码223、225个氨基酸.系统分析结果显示:鳜鱼GSTA与GSTR在进化树上的位置与其分类所处的位置基本吻合.     

THE EFFECTS OF CHLORINE,ELEVATED TEMPERATURE AND EXPOSURE DURATION OF POWER PLANT EFFLUENTS ON LARVAL WHITE PERCH Morone americana (Gmelin)1

ABSTRACT: Chlorine-temperature interaction studies with various exposure times were conducted on 25–day old larval white perch, Morone Americana, using total residual chlorine (TRC) concentrations of 0.0, 0.15, and 0.30 mg/1 TRC in combination with ΔTs of 2, 6, and 10 C above a base temperature of 18 C. Larval fish were exposed to the chlorine-temperature test conditions for exposure periods of 0.08, 2.0 and 4.0 hours. After each respective exposure period, chlorine concentrations were decayed naturally over a 1.0 to 1.5 hour period to < 0.01 mg/1 TRC; temperatures were decayed over a 4 hour period to 2.0 C above the base temperature. These test conditions were used to simulate chlorine and temperature conditions encountered in power plant discharge canals and near field receiving streams. The interactions of chlorine, ΔT and exposure duration as factors which caused death up to 36 hours after the exposure periods were established by regression model techniques. An initial interaction model showed that ΔT was not a factor which contributed to death. A predictive model for chlorine and exposure duration was constructed which showed that potential impact to larval white perch from chlorine at power facilities with once through cooling systems can be minimized by 1) using short duration exposures (< 1 hour) to chlorine in plants that chlorinate intermittently or 2) by rapid mixing in the receiving stream in plants that chlorinate on a low level (< 0.05 mg/1) continuous basis. Similar considerations should be given to cooling tower blowdown which contain chlorinated water.     

Ⅱ824^—2综放工作面瓦斯综合治理试验研究

通过对淮北芦岭矿Ⅱ824^-2综放工作面瓦斯综合治理的试验研究，摸索出了高瓦斯综放工作面瓦斯治理的有效方法，取得了较好的瓦斯抽放和通风排放效果。     

Enzymatic and cellular level effects of chromium∗

Exposure of Cr to four hepatic enzymes activities of tilapia, viz. acid‐ and alkaline phosphatases, catalase and glucose‐6‐phosphatase, was contrary to the results obtained for Cd and Ni. This is the only heavy metal investigated thus far that dramatically augmented glucose‐6‐phosphatase by approximately 83% at a concentration of 12 mg L^‐1 in vivo in lieu of the fact of an initial inhibition of approximately 45 % at a lower concentration of Cr; 6 mg L^‐1. In the case of acid phosphatase and catalase activities progressive increment was observed up to 50 and 217% respectively at a concentration of 12 mg L^‐1 Cr. On the other hand, in contrast to all the investigated enzymes interestingly alkaline phosphatase was inhibited continuously at all concentrations up to 46% at 12 mgL^‐1 Cr. In vitro experiments were contrary to the above mentioned results, whereby all hepatic enzymes were inhibited with major inhibition observed for acid phosphatase of approximately 60% from 5 mgL^‐1 Cr onwards in the system.

At cellular level, Cr exposure at a lethal dose of 12 mgL^‐1 demonstrated similar effects to that of Cd. In general, the glycogen and fat reserves were depleted while lysosomal activity is increased. As compared to the effects of Cd, the mitochondria did not indicate any prominent reflection in the formation of intramitochondrial bodies. Further, similar to Cd, the cell membrane as well as nucleus were not affected.