Determination of the swimming trajectory and speed of chain-forming dinoflagellate <Emphasis Type="Italic">Cochlodinium polykrikoides</Emphasis> with digital holographic particle tracking velocimetry

The marine dinoflagellate Cochlodinium polykrikoides is a harmful and highly motile algal species. To distinguish between the motility characteristics of solitary and chain-forming cells, the swimming trajectories and speeds of solitary cells and 2- to 8-cell chains of C. polykrikoides were measured using a digital holographic particle tracking velocimetry (PTV) technique. C. polykrikoides cells exhibited helical swimming trajectories similar to other dinoflagellate species. The swimming speed increased as the number of cells in the chain increased, from an average of 391 μm s⁻¹ (solitary cells) to 856 μm s⁻¹ (8-cell chain). The helix radius R and pitch P also increased as the number of cells in the chain increased. R increased from 9.24 μm (solitary cell) to 20.3 μm (8-cell chain) and P increased from 107 μm (solitary cell) to 164 μm (8-cell chain). The free thrust-generating motion of the transverse flagella and large drag reduction in the chain-forming cells seemed to increase the swimming speed compared to solitary cells. The measured swimming speeds agreed with those from field observations. The superior motility of chain-forming C. polykrikoides cells may be an important factor for its bloom, in addition to the factors reported previously.     

复合多管除尘器在湿法水泥回转窑除尘中的应用

把具有惯性沉降除尘、旋风子除尘两级一体功能的复合多管除尘器用于带湿式蒸发器的湿法水泥回转窑尾气除尘，替换原“旋风除尘器＋电除尘器”除尘系统中的多筒旋风器。运行测试表明，它的除尘效率达到９４６％，确保了窑尾排放烟尘浓度达到国家标准。     

Metal recovery from mine tailings using bacteria

Zinc metal and zinc sulfide were recovered by oxidative dissolution using Thiobacillus ferrooxidans, which is aerobic, autotrophic, and acidophilic bacteria. Thiobacillus ferrooxidans derive energy from oxidation of ferrous iron and elemental sulfur using molecular oxygen as an electron acceptor. From the 10, 000 mg/L of initial zinc concentration, 97% solubilization of zinc metal was obtained from coarse FeS₂ due to microbial action. Also, about 70% metal solubilization occurred with fine sized materials in 58 days. The general trend observed for the ZnS systems was a decrease in pH with time. The pH drop is an indication that microorganisms are acclimating and producing acidic by-products. The iron oxidation state changes due to substrate containing coarse particle size FeS₂ was shown. The shard drop of ratio of Fe(II)/Fe(Total) and sharp increase of ratio of Fe(III)/Fe(Total) was observed in 20 days after inoculation. Thus, microbial activity began more rapidly for the coarse particle size substrate than for the fine FeS₂.     

中国环境影响评价机构现状评价及优化调整思路

根据环境保护部环境工程评估中心公布的数据,中国环境影响评价机构现状特点是：环评机构的主要类型以科研院所占比例最大,其次是公司,最少的是高等院校;区域分布特点是东部多,西部少,经济发达地区多。经济欠发达地区少;评价范围特点是从事社会区域类别的环评机构最多,其次是化工石化医药类。同时,结合中国地区经济数据和市场化的要求,指出中国环评机构的数量与区域经济状况不对称,部分环评机构的评价范围与区域产业结构不匹配,环评机构市场化程度不高。最后,提出优化中国环境影响评价机构的建议。     

阻燃防护服防火性能及发展趋趋势

介绍了阻燃防护服的性能要求、国内外阻燃防护服防火性能检测方法的研究及发展趋势.     

基于灰色理论的甲型H1N1流感传染人数预测模型研究

就我国甲型H1N1流感传染人数的预测运用灰色系统理论,建立了GM（1,1）模型和1阶残差修正模型GMε（1,1）,并分别作了精度分析。研究了GMε（1,1）的变化趋势,提出了临界值和有效域概念。用MATLAB确定了模型参数及模型预测值。     

苏州河沉积物中的PCDD/Fs研究

用酶联免疫检测方法对苏州河沉积物PCDD/Fs进行分析,结果表明,PCDD/Fs水平在3.6～13.7TEQpg/gdw之间(平均值为8.4TEQpg/gdw)。PCDD/Fs含量的空间分布差异较大,中游含量高于上游和下游。对柱状沉积物的分析显示,沉积物PCDD/Fs含量在9.0～18.8TEQpg/gdw之间(平均值为13.8TEQpg/gdw),1996年前后达到峰值。通过对苏州河PCDD/Fs组成模式进行主分量分析发现,河流沉积物的PCDD/Fs为混合来源,其中污水排放的贡献较大。     

城区内小型加油站的消防安全对策

通过对遵义市高庄(东)加油站进行实例分析,发现加油站安全管理体制不健全,违章作业表现突出,存在消防安全隐患;结合实例分析结果,得出城区内小型加油站的消防安全对策.     

Transfer of 90Sr to rice plants after its acute deposition onto flooded paddy soils

The transfer of 90Sr to rice plants following its acute ground deposition was examined experimentally in a greenhouse. Lysimeters were flooded after being filled with the soil monoliths from 12 paddy fields. A solution of 90Sr was applied to the standing water in the flooded lysimeters at the pre-transplanting stage or booting stage. Applied 90Sr was mixed with the topsoil only after the pre-transplanting application (PTA). The transfer was quantified with the areal transfer factor (TF(a), m2 kg(-1)-dry) defined as the ratio of the plant concentration to the initial ground deposition. In the PTA, the first-year TF(a) values in the 12 soils were in the range of 8.2 x 10(-3) -2.1 x 10(-2) and 1.7 x 10(-4) -3.6 x 10(-4) for the straws and hulled seeds, respectively. The TF(a) values from the booting-stage application (BSA) were higher than those from the PTA by a factor of up to four. The ratios of the seed TF(a) to the straw TF(a) were, on the whole, higher in the BSA. The 90Sr TF(a) in the PTA was negatively correlated with the soil pH and, to a lesser degree, the exchangeable Ca content. In the second year, the TF(a) in the PTA reduced to 53-90% of that in the first year. A more significant reduction, in general, occurred in a sandier soil. Based on the four consecutive years' transfer data, an overall half-time of the 90Sr TF(a) was estimated to be 2.2 years.