The study for polyaromatic hydrocarbons decay on Chinese coal soot particles in atmosphere

A study for the photochemical behavior of some polyaromatic hydrocarbons (PAH), for example B(a )P, B( k )F and fluoranthene in coal smoke particles was performed by using indoor Teflon smog chamber.Experiments suggest that the photochemical reaction of PAH is first order reaction and kinetic rates of some PAH were obtained. It was shown that the reaction rate constant is proportional to light intensity and water vapor concentration. Temperature and PAH loading also have influence on PAH decay rate. A model for PAH loss has been set up on the basis of the results of our experiments and the simulating results of this model suggest that coal particle PAH half lives are of the order of a period of days in winter and a few hours in summer. Other factors which may have effect on the photochemical reaction of PAH have also been discussed.     

The hierarchy and spatial characteristics of ecosystems: A reconsideration of the ecosystem concept (II)

This paper, based on the autonomy concept, continues to investigate hierarchical forms and spatial structure of ecosystems. The former can lead to limits for the selection of the component parts of an ecosystem and a distinction between its endogenous and exogenous variables; and the latter can be lead to a hypothesis of the space of an ecosystem: the space of an ecosystem = its habitat area + supporting area + impact area, and two characteristics of ecosystems, space-overlapping and the area of ecosystem space, have been further studied referring to human activities.     

Effects of Ca2+ ions antagonistic to Al3+ ions poisoningin root growth , cell division and nucleolusin root tip cells of Allium cepa

The effects of different aluminium chloride concentrations together with varying calciumchloride concentrations on root growth, cell division and nucleoli in root tip cells of Allium cepa werestudied. The concentrations used for aluminium chloride were 10^-4, 10^-3 and 10^-2 mol/L ; and for calcium chloride were 10^-5 , 10^-4 , 10^-3 and 10^-2 mol/L, respectively. The results showed that after thetreatments with 10^-2 to 10^-3 mol/L Al³⁺ , root growth was severely inhibited , a large nurnber of thecells with c-mitosis were induced and the nucleolar material was extruded from the nucleus into the cytoplasm. However , the treatments with 10^-2 to 10^-3 mol/L of Al³⁺ together with 10^-2)to 10^-5 mol/LCa²⁺ suggested that Ca²⁺ gave the obviously protective effects against Al³⁺ poisoning in root growth.cell division and nucleoli of the root tip cells in A. cepa. The possible mechanism of these protective effects of Ca²⁺) is also briefly discussed.     

Effects of lead , cadmium , mercury chlorides and aquaticenvironmental samples on the growth of Escherichia coli

In this paper it was reported that PbCl₂ , CdCl₂ , HgCl₂, and aquatic environmental samples containing Al, Cd, Cu, Pb, Sr, Zn and other heavy metal ions as well as organic chemicals suppressed thegrowth of E. coli only at higher exposed concentrations. The stimulative effects of PbCl₂ and HgCl₂ on thegrowth of E. coli were clearly showed at lower concentrations and longer time. It suggested that the toxic effects of heavy metal ions and other pollutants on the growth of E. coli are variable according to the differentexposed levels.     

烟气对人体的危害及研究

丙纶强力丝在加工过程中，聚丙烯在高温下发生分解，产生有害烟气，造成操作环境污染，危害人体健康．采用提高抽风机位置，加大排风量，改进风机换气次数等措施，除烟率达85％以上．     

The buffering effects of aquatic sediments against acidic deposition

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膜生物反应器与传统活性污泥工艺除污特性比较

比较了膜生物反应器（MBR）和传统活性污泥工艺（CAS）在相同运行条件下对生活污水的除污特性.结果表明,MBR系统对COD、NH3-N和TN的平均去除率比CAS分别高14.4%、51.2%和37.3%.但MBR中膜的截留使系统相对比较封闭,制约了通过排放高磷污泥的生物法除磷,除磷效率仅为32.9%,低于CAS工艺（43.0%）;将MBR与化学除磷工艺相结合,MBR系统除磷效率可达93.3%.