The distribution of intertidal phytopsammon in an Oregon estuary

The sediments of two tidal flats in Yaquina Bay, Oregon, USA, were studied to determine the distribution and abundance of the interstitial microalgal communities. The hydrography of the bay, as well as fluetuations in various physical and chemical parameters appear to regulate the biomass and the vertical and intertidal distribution of these organisms.     

Benthic ecology of the high arctic deep sea

An analysis is made of 75 quantitative benthic samples collected by Mini-LUBS, and 28 qualitative benthic samples collected with the small biological trawl, from Fletcher's Ice Island, T-3, while it was drifting over the Alpha Cordillera region of the High Arctic Ocean during October, 1969 through February, 1970 and in March, 1972. The depth range was 1000 to 2500 m. Benthic foraminiferans account for about 53%, bivalves for 27%, sponges for 7%, and polychaetes for 5% of the total biomass. Other groups make up the remaining 8%. The weight ratio of macro- to meiofauna is 1:1. Numerically, excluding Foraminifera, polychaetes comprise 42%, nematodes 16%, sponges 11%, and bivalves 8% of the total fauna. The remaining 23% is composed of 13 other taxa. Biomass in the Amerasian Basin at depths of 1000 to 2000 m is extremely low (0.04 g/m); it is comparable to depths of 5000 to 6000 m in the oligotrophic red-clay area of the mid-Pacific Ocean, and is 40 times less than biomass at comparable depths from Antarctica and off Peru. Diversity, as calculated by the Shannon-Weaver method, is low, suggesting that the Arctic ecosystem is young, as reported in earlier studies (Dunbar, 1968; Menzies et al., 1973). Although the H' values are low, no biocoenoses of oligomixity in the deep Arctic are revealed, contrary to previous statements and beliefs. There may be fewer major benthic groups in the Arctic Ocean than in other parts of the world oceans. Following the conventional terminology of Petersen (1913) and Thorson (1957), we have called the High Arctic biocoenoses of the Alpha Cordillera region a Thenea abyssorum-Spirorbis granulatus community.     

A further contribution to the study of fish populations by capture-recapture experiments

In capture-recapture experiments, fish populations can be studied by two different sampling procedures. In both procedures, tagged fish are released on capture, but untagged fish are in one procedure released after tagging, in the second procedure they are retained. Using the two sampling techniques, Rafail (1971a,b) gave expressions for the estimation of an assumed constant (C) of proportionality between probabilities of capture of tagged to untagged fish which are simplified here to forms easier for calculation. The estimation of this constant (C) aids in estimation of abundance and mortality rates of untagged fish which are assumed to differ from those of tagged fish.     

催化铝内电解工艺降解活性艳红的研究

通过对催化铝内电解工艺对偶氮染料活性艳红去除效率的研究,得出该工艺去除活性艳红主要是通过电化学作用,絮凝作用和还原作用完成的.其中絮凝作用大约占总去除效率的18.4%,还原作用约占21.7%.     

Sensitivity of future ozone concentrations in the northeast USA to regional climate change

An air quality modeling system was used to simulate the effects on ozone concentration in the northeast USA from climate changes projected through the end of the twenty-first century by the National Center for Atmospheric Research’s (NCAR’s) parallel climate model, a fully coupled general circulation model, under a higher and a lower scenario of future global changes in concentrations of radiatively active constituents. The air quality calculations were done with both a global chemistry-transport model and a regional air quality model focused on the northeast USA. The air quality simulations assumed no changes in regional anthropogenic emissions of the chemical species primarily involved in the chemical reactions of ozone creation and destruction, but only accounted for changes in the climate. Together, these idealized global and regional model simulations provide insights into the contribution of possible future climate changes on ozone. Over the coming century, summer climate is projected to be warmer and less cloudy for the northeast USA. These changes are considerably larger under the higher scenario as compared with the lower. Higher temperatures also increase biogenic emissions. Both mean daily and 8-h maximum ozone increase from the combination of three factors that tend to favor higher concentrations: (1) higher temperatures change the rates of reactions and photolysis rates important to the ozone chemistry; (2) lower cloudiness (higher solar radiation) increases the photolysis reaction rates; and (3) higher biogenic emissions increase the concentration of reactive species. Regional model simulations with two cumulus parameterizations produce ozone concentration changes that differ by approximately 10%, indicating that there is considerable uncertainty in the magnitude of changes due to uncertainties in how physical processes should be parameterized in the models. However, the overall effect of the climate changes simulated by these models – in the absence of reductions in regional anthropogenic emissions – would be to increase ozone concentrations.     

火灾爆炸危险指数法在油库风险评价中的应用

油库由于储存物料的易燃易爆等特性,一般构成重大危险源,易于发生火灾爆炸事故,采用美国道化学公司的火灾爆炸危险指数法（FEI）,对油库火灾爆炸事故的危险性进行定量分析,计算火灾、爆炸危险指数（F＆EI）,确定油库火灾爆炸事故的影响范围,并针对事故影响范围内的设施制定防范措施,给出安全措施补偿系数,经安全措施补偿后,火灾、爆炸危险指数（F＆EI）减少,事故危险等级降低,事故影响范围缩小,为油库工程的风险管理提供理论依据。     

Plutonium isotopes in surface air of Prague in 1986-2006

Monitoring of (239,240)Pu in surface air of Prague started in 1986 in connection with the Chernobyl accident. Measurable activities of 10-28muBqm(-3) were found from 29 April 1986 to 5 May 1986. In the most of the monitoring periods of 1987-1996, activities of (239,240)Pu in air were not measurable. Positive values for (239,240)Pu and (238)Pu in air could be obtained after installation of an aerosol sampler with higher flow-rate in 1997. Activity concentrations of (239,240)Pu and (238)Pu in Prague air in the most of quarters of 1997-2006 were in the range 0.53-5.06 and <0.16-1.10nBqm(-3), respectively. Seasonal fluctuations can be found in content of (239,240)Pu in air. Activity ratios of (238)Pu/(239,240)Pu in air are higher than those in top soil, so it can be supposed that (238)Pu is coming to air of Prague also from other sources than resuspension of fallout from atmospheric nuclear tests.