我国安全生产基层执法队伍建设问题与对策

通过收集分析相关统计数据和资料,深入分析我国安全生产基层执法队伍建设现状。统计分析结果表明:专门的基层执法机构仍不健全;与基层实际执法工作需要相比,执法人员相对不足;执法人员业务素质不高;执法队伍不稳定,人员变动频繁。最后从建立人员配备标准、合理调配人员、加快监察人员专业化建设进程、落实从优待安政策等4方面,提出了相应的对策。     

The effects of pruning and nodal adventitious roots on polychlorinated biphenyl uptake by Cucurbita pepo grown in field conditions

Two cultivation techniques (i-pruning and ii-nodal adventitious root encouragement) were investigated for their ability to increase PCB phytoextraction by Cucurbita pepo ssp pepo cv. Howden (pumpkin) plants in situ at a contaminated industrial site in Ontario (Aroclor 1248, mean soil [PCB] = 5.6 μg g⁻¹). Pruning was implemented to increase plant biomass close to the root where PCB concentration is known to be highest. This treatment was found to have no effect on final shoot biomass or PCB concentration. However, material pruned from the plant is not included in the final shoot biomass. The encouragement of nodal adventitious roots at stem nodes did significantly increase the PCB concentration in the primary stem, while not affecting shoot biomass. Both techniques are easily applied cultivation practices that may be implemented to decrease phytoextraction treatment time.     

黑麦草根际强化微生物净化甲苯

采用在普通生物反应器上种植黑麦草的方法,研究了黑麦草根系强化微生物净化甲苯污染气体的作用,及甲苯入口浓度、填料深度、温度对反应器净化甲苯速率的影响。结果表明,在生物反应器相同的填料深度,细菌数量的水平分布为黑麦草根际区>过渡区>非根际,与相同位置的甲苯浓度分布呈负相关,说明黑麦草根系通过促进细菌的活性进而增加甲苯的降解。在相同的甲苯入口浓度下,甲苯的净化速率随着填料深度的增加而增加,在甲苯入口浓度不高于500 mg/m3条件下,相同的填料深度,反应器对甲苯的净化速率随着甲苯浓度的增加而增加。在5~35℃范围内,温度升高有助于提高微生物活性,促进微生物对甲苯的降解,且有黑麦草处理的甲苯净化速率大于同等条件下无黑麦草处理。     

水生植物根系对多环芳烃(萘)吸附过程研究

对萘在水葫芦根系的吸附过程进行模拟研究 ,结果表明 ,新鲜水葫芦根系对萘不仅具有吸附作用 ,而且还具有吸收或根际微生物降解等作用 ;水葫芦根系吸附萘的初始速率与浓度符合一级反应动力学 ;吸附过程可用Langmuir公式表示的单分子层吸附模型描述。     

测定方法和植物生长对土壤呼吸的影响

2.中国科学院研究生院,北京100039摘要:植物根系活动和测定方法是研究陆地生态系统土壤呼吸的重要影响因素。文章通过动态气室-IRGA法和静态气室-GC法研究了田间受根系影响和不受根系影响土壤的呼吸速率,分析了根系活动对土壤呼吸速率的影响程度,并比较了两种测定方法间的差异。研究表明,受根系影响处理的土壤呼吸速率显著高于不受根系影响的处理;受根系活动影响处理的土壤呼吸速率为静态气室-GC法>动态气室-IRGA法;而不受根系活动影响处理的土壤呼吸速率则恰好相反,为动态气室-IRGA法>静态气室-GC法;两种方法在测土壤呼吸时存在显著差异;但两种方法所测土壤呼吸速率间呈极显著的线性相关;两种方法间所获数据可以互相转换参比。     

Natural attenuation/phytoremediation in the vadose zone of a former industrial sludge basin

The natural attenuation of polyaromatic hydrocarbons (PAHs) in the vadose zone of a naturally revegetated former industrial sludge basin (0.45 ha) was examined. This was accomplished by comparing the concentration of 16 PAH contaminants present in sludge collected below the root zone of plants with contaminants present at 3 shallower depths within the root zone. Chemical analysis of 240 samples from 60 cores showed the average concentration of total and individual PAHs in the 0-30 cm, 30-60 cm, and bottom of the root zone strata were approximately 10, 20, and 50%, respectively, of the 16, 800 ppm average total PAH concentration in deep non-rooted sludge. Statistically significant differences in average PAH concentrations were observed between each strata studied and the non-rooted sludge except for the concentrations of acenaphthene and chrysene present at the bottom of the root zone in comparison to sludge values. The rooting depth of the vegetation growing in the basin was dependent on both vegetation type and plant age. Average rooting depths for trees, forbs (herbaceous non-grasses), and grasses were 90, 60, and 50 cm, respectively. The deepest root systems observed (100-120 cm) were associated with the oldest (12-14 year-old) mulberry trees. Examination of root systems and PAH concentrations at numerous locations and depths within the basin indicated that plant roots and their microbially active rhizospheres fostered PAH disappearance; including water insoluble, low volatility compounds, i.e. benzo(a)pyrene and benzo(ghi)perylene. The reduced concentration of PAHs in the upper strata of this revegetated former sludge basin indicated that natural attenuation had occurred. This observation supports the concept that through appropriate planting and management practices (phytoremediation) it will be possible to accelerate, maximize, and sustain natural processes, whereby even the most recalcitrant PAH contaminants (i.e. benzo(a)pyrene) can be remediated over time.     

Ri质粒诱导喜树毛状根培养基中喜树碱的研究

喜树(Camptotheca acuminate)可产生具有抗癌作用的喜树碱,有许多用细胞培养方法制备喜树碱的尝试,但都因极低的产率而无从深入。植物毛状根培养的应用将成为一种生物碱生产的替代方法。以发根农杆菌(Agrobacterium rhizogenes)A41.2556感染喜树诱导产生毛状根,建立喜树碱毛状根产生体系。甘露碱检测及PCR结果证实发根农杆菌Ri质粒的rolB基因已在喜树毛状根基因组中整合并得到表达。确定了用RP-HPLC测定发根培养基中喜树碱的的方法,比较了不同的吸附树脂对培养基中喜树碱的富集能力,从培养30d的喜树培养基中获得喜树碱干质量分数为0.14mg·g-1。     

土壤污染对植物根系生长影响的研究进展

人类活动所产生的污染物通过各种途径进入土壤,其数量和速度超过了土壤的容纳和净化能力,致使土壤的自然功能失调、土壤质量恶化,从而严重影响植物的正常生长发育,造成有害物质在植物体内累积。土壤污染物进入植物体内最先进入根系,污染物在根系积累最大,浓度最高,根部受害最严重。本文以重金属砷、镉、铬和有机物农药、除草剂为例,结合相关资料探讨了土壤污染对植物根系生长的影响,植物根系对重金属的吸收与重金属的理化性质及不同植物的特性有关,对有机物的吸收与有机物的结构特性和土壤性质有关,并且讨论了该研究仍需解决的一些问题。     

铜尾矿对5种豆科植物根系生长的影响

针对铜陵市铜尾矿废弃地的复垦，选用了5种乡土豆科植物在5种不同的尾矿改良方式上进行盆栽试验。5种供试物种为：大豆(Glycine max)、赤豆(Phaseolus angularis)、赤小豆(P.calcaratus)、绿豆(P.radiatus)、山绿豆(P.mininus)。盆栽基质是以尾矿与正常土壤按体积100：0、75：25、50：50、25：75、0：100比例混合而成，分别标记为：TAl00、TA75、TA50、TA25、TA0005种豆科植物生长时间为70d。结果发现：随铜尾矿在混合基质中比例的增加，5种豆科植物根系的主根长逐渐变短、根系一级侧根的数目逐渐减少；铜尾矿对5种豆科植物根瘤的形成产生抑制作用，特别是山绿豆和绿豆在全尾矿的基质上，无根瘤生成；地下根部的生物量表现为随着尾矿含量比例的增加。地下部分的生物量逐渐下降，但根冠比表现为随尾矿含量比例的增加而增加；植物对铜尾矿中铜的积累，主要含集中根部，地上部分与地下部分差异明显。     

ICP-MS法用于藕中多元素的分析

用ICP-MS法对藕中的多元素进行分析。并与北京市安全食用农产品产品质量标准所涉及到蔬菜中Cd,Zn,As,Pb,Cu和Hg的标准值进行对比。结果表明，北京地区七个不同菜市场所售的藕除个别Zn含量超标外，其它元素均符合标准。