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961.
生活中,苍蝇是恼人的小东西,但是机器苍蝇却彻底改变了人们这一观点。这种听上去似乎在007等谍战电影中才会出现的玩意,现在真的已经成为现实。机器苍蝇的体重只有60毫克,翼展长度也仅仅有3厘米,是典型的仿生学产品,其飞行运动原理和真的苍蝇非常相似。经过十多年研制,世界上首款机器苍蝇在哈佛成功起飞。近 相似文献
962.
郑社教 《安全.健康和环境》2011,11(8):12-14
依据HSE管理体系标准,结合有关安全工程理论和风险管理理论与方法,提出了HSE风险管理的思想模式,对其含义和指导意义进行了说明。 相似文献
963.
采用美国EPA规定的水中优先控制污染物的水体有机物浓度标准,计算滇池罗家营水域中污染物的健康风险,并参考美国EPA对致癌风险和非致癌风险的相关定义,对这些化合物的环境健康风险进行了评价。结果表明:2007年滇池罗家营水域污染物非致癌及致癌健康风险值均低于美国EPA给出的参考标准,表明该水域水总污染物不会对人体健康产生风险。 相似文献
964.
为研究宁波市大气污染状况及其影响因素,利用2013—2018年宁波市国控站点实时监测污染物数据以及气象数据,探讨分析了宁波市大气污染特征以及所受气象因素的影响概况。结果表明:宁波市颗粒物污染和O3污染呈现典型的季节性特征,颗粒物浓度冬季最高,O3最大滑动8 h平均质量浓度春、秋季最高。宁波市O3污染问题越来越突出,且呈现出春、秋季O3超标天数最多的季节变化特征。O3小时质量浓度与气温和太阳辐射成正相关关系,NO2和颗粒物浓度与气温成负相关关系。NO2与O3浓度成负相关关系,与颗粒物浓度成正相关关系。 相似文献
965.
966.
Two honey samples are taken from two parts of the same honeycomb: one that contacts to the surface of the wire and the other
taken from the surface that does not contact the wires. Heavy metal contents of these two samples were determined by inductively
coupled plasma atomic emission spectrometry). The Mo, Cd, Cr, Fe, Mn, Ni and Zn contents of the honey in contact with wire
is higher when compared to the other. Especially, Fe and Zn contents of honey in contact with wire is much higher than the
non-contact one. These values are, respectively, 190.21 and 112.76 ppm. Besides, Ni content of honey in contact with wire
is approximately 50% higher. 相似文献
967.
Benincá C Ramsdorf W Vicari T de Oliveira Ribeiro CA de Almeida MI Silva de Assis HC Cestari MM 《Environmental monitoring and assessment》2012,184(4):2045-2056
Biological monitoring through animals exposed to pollutants using biomarkers provides a promising tool for the identification
of pollutants that may cause damage to human health and/or to sustainability of ecosystems. The effects of pollutants in fish
tissues are important tools to understand the impact of human activities in natural ecosystems. The aim of this work was to
study the water quality of two estuarine lakes in Santa Catarina, Brazil (Camacho Lake and Santa Marta Lake). Geophagus brasiliensis is a species widely distributed in Brazil and was used in this work. Comet assays in peripheral red blood and kidney cells,
micronucleus tests in peripheral red blood cells, measurements of acetylcholinesterase activity in axial muscle and histopathological
analysis of liver were used as biomarkers. Three sampling campaigns were undertaken in November 2004, June 2005 and November
2005. Thirty adult animals were sampled from each of three different sites (P1—Santa Marta Lake, P2 and P3—Camacho Lake).
A negative control was sampled in a non-polluted site at Costa Ecological Park, Paraná. The positive control for genotoxicity
was obtained by treating animals with copper sulphate. The results showed that both studied lakes are impacted by potential
genotoxic substances. Severe lesions in liver of G. brasiliensis were also observed. The inhibition of acetylcholinesterase activity suggests the presence of pesticides or metals in the
studied sites. This work shows that the water quality of Santa Marta and Camacho Lakes have been compromised and further control
source of pollutants into these ecosystems is required. 相似文献
968.
Micro- and macro-element contents of several commercial fruit juices purchased from marked were determined by inductively coupled plasma atomic emission spectroscopy. Among the minor elements determined, Zn, Cu, Mn, Mo, Co, Cd and Ni were found to be lover. Major mineral contents of fruit juices were established as Ca, K, Mg and P. The potassium contents of fruit juices were determined at the higher levels. K contents of fruit juices ranged between 475 mg/kg (B apricot) and 1478 mg/kg (B peach). In addition while Ca contents of fruit juices change between 19.3 mg/kg (E cherry) and 81.8 mg/kg (C orange), Mg contents ranged at the levels between 23.7 mg/kg (A apricot) and 65.4 mg/kg (D orange). Generally Ca and contents of peach, orange and apricot juices that belong to A and D companies were determined at the high levels. 相似文献
969.
Antonijević MM Dimitrijević MD Milić SM Nujkić MM 《Journal of environmental monitoring : JEM》2012,14(3):866-877
In this study concentrations of metals in the native plants and soils surrounding the old flotation tailings pond of the copper mine were determined. It has been established that the soil is heavily contaminated with copper, iron and arsenic, the mean concentrations being 1585.6, 29,462.5 and 171.7 mg kg(-1) respectively. All the plants, except manganese, accumulated metallic elements in concentrations which were either in the range of critical and phytotoxic values (Pb and As) or higher (Zn), and even much higher (Cu and Fe) than these values. Otherwise, the accumulation of Mn, Pb and As was considerably lower than that of Cu, Fe and Zn. In most plants the accumulation of target metals was highest in the root. Several plant species showed high bioaccumulation and translocation factor values, which classify them into species for potential use in phytoextraction. The BCF and TF values determined in Prunus persica were 1.20 and 3.95 for Cu, 1.5 and 6.0 for Zn and 1.96 and 5.44 for Pb. In Saponaria officinalis these values were 2.53 and 1.27 for Zn, and in Juglans regia L. they were 8.76 and 17.75 for Zn. The translocation factor in most plants, for most metals, was higher than one, whereas the highest value was determined in Populus nigra for Zn, amounting to 17.8. Among several tolerant species, the most suitable ones for phytostabilization proved to be Robinia pseudoacacia L. for Zn and Verbascum phlomoides L., Saponaria officinalis and Centaurea jacea L. for Mn, Pb and As. 相似文献
970.
EIN3/EIL家族是一类非常重要的转录因子,调控植物包括果实成熟在内的众多生长发育过程.对中华猕猴桃EIN3/EIL家族进行系统的生物信息学和比较基因组学研究,在中华猕猴桃基因组中鉴定得到8个EIN3/EIL转录因子;其蛋白序列包括1个酸性氨基酸富集区、1个脯氨酸富集区以及5-7个碱性氨基酸富集区.包括中华猕猴桃在内的20种植物的EIN3/EIL成员的系统进化树表明,EIN3/EIL基因在众多植物基因组中同时存在趋同和趋异的进化趋势.中华猕猴桃EIN3/EIL基因家族成员的增加主要源于其进化过程中发生的全基因组三倍化倍增事件.在果实成熟过程中,中华猕猴桃EIN3/EIL基因呈现组成型的高或低表达两种截然相反的基因表达趋势.本研究鉴定得到了中华猕猴桃EIN3/EIL家族的成员,系统揭示了其成员蛋白序列中的保守区域、在不同植物物种中的进化趋势,植物基因组倍增所导致的家族成员增加,以及果实发育过程中表现出的显著的基因表达水平差异,可为中华猕猴桃EIN3/EIL基因的功能研究提供候选基因以及数据基础. 相似文献