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181.
为探究金属矿井下粉尘孔粒径特征,以阜山金矿为例,系统研究其进风巷粉尘(IAD)、回风巷粉尘(RAD)的孔粒径分布(PSD)情况.首先,利用激光粒度分析仪与扫描电子显微镜(SEM)、低温液氮吸附仪分别测试粉尘粒径与孔参数,然后利用分形理论计算并分析其粒度分形维数与孔分形维数.结果 表明:RAD粒径比IAD粒径小,两者最可...  相似文献   
182.
So far, very little is known about mercury stress-induced intercellular metabolic changes in rice roots at the proteome level. To investigate the response of rice roots to mercury stress, changes in protein expression in rice roots were analyzed using a comparative proteomics approach. Six-leaf stage rice seedlings were treated with 50 μmol/L HgCl2 for 3 hr; 29 protein spots showed a significant changes in abundance under stress when compared with the Hg2+-tolerant rice mutant and wild type (Zhonghua 11). Furthermore, all these protein spots were identified by mass spectrometry to match 27 diverse protein species. The identified proteins were involved in several processes, including stress response, redox homeostasis, signal transduction, regulation and metabolism; some were found to be cellular structure proteins and a few were unknown. Among the up-regulated proteins, OsTCTP (translationally controlled tumor protein) was chosen to perform hetereologous expression in yeast which was presumed to participate in the Hg2+ tolerance of rice, providing evidence for its role in alleviating Hg2+ damage. Among the many tests, we found that OsTCTP-overexpressed yeast strains were more resistant to Hg2+ than wild-type yeast. Thus, we propose that OsTCTP contributes to Hg2+ resistance. Here we present, for the first time, the functional characterization of OsTCTP in connection with Hg2+ stress in plants.  相似文献   
183.
The critical paths for radionuclides and the critical foods in Asian countries differ from those in Western countries because agricultural products and diets are different. Consequently, safety assessments for Asian countries must consider rice as a critical food. As most rice is produced under flooded conditions, the uptake of radionuclides by rice is affected by soil conditions. In this report, we summarize radionuclide and stable element soil-to-plant transfer factors (TFs) for rice. Field observation results for fallout 137Cs and stable Cs TFs indicated that while fallout 137Cs had higher TF than stable Cs over several decades, the GM (geometric mean) values were similar with the GM of TF value for 137Cs being 3.6 × 10−3 and that for stable Cs being 2.5 × 10−3. Although there are some limitations to the use of TF for stable elements under some circumstances, these values can be used to evaluate long-term transfer of long-lived radionuclides in the environment. The compiled data showed that TF values were higher in brown rice than in white rice because distribution patterns for elements were different in the bran and white parts of rice grains.  相似文献   
184.
针对CO_2驱油封存技术,我国在环境监测、环境影响评价等领域的环境监管能力建设还处于空白,亟待加强。文章从CO_2泄漏路径分析、环境监测方法的筛选以及环境背景值缺失情况下的监测数据分析方法等三个方面阐述了各环节的主要研究思路。其中重点介绍了"过程分析法"在CO_2泄漏识别中的应用,强调环境背景值不仅是注气前的环境状况,在注气过程中,每个时间点之前的监测数据均可以看作是背景值。为我国制定相关的法律法规提供重要信息和参考依据。  相似文献   
185.
As a diagenetic progress, bioturbation influences solute exchange across the sediment-water interface (SWI). Different benthic animals have various mechanical activities in sediment, thereby they may have different effects on solute exchange across the SWI. This laboratory study examined the impacts of different benthic animals on phosphorus dynamics across the SWI. Tubificid worms and Chironomidae larvae were introduced as model organisms which, based on their mechanical activities, belong to upward-conveyors and gallery-diffusers, respectively. The microcosm simulation study was carried out with a continuous flow culture system, and all sediment, water, and worms and larvae specimens were sampled from Taihu Lake, China. To compare their bioturbation effects, the same biomass (17.1 g wet weight (ww)/m2) was adopted for worms and larvae.Worms altered no oxygen penetration depth in sediment, while larvae increased the O2 penetration depth, compared to the control treatment. Their emergence also enhanced sediment O2 uptake. The oxidation of ferrous iron in pore water produced ferric iron oxyhydroxides that adsorbed soluble reactive phosphorus (SRP) from the overlying water and pore water. Larvae built obviously oxidized tubes with about 2 mm diameter and the maximum length of 6 cm in sediment, and significantly decreased ferrous iron and SRP in the pore water compared to the control and worms treatments. Worms constructed no visually-oxidized galleries in the sediment in contrast to larvae, and they did not significantly alter SRP in the pore water relative to the control treatment. The adsorption of ferric iron oxyhydroxides to SRP caused by worms and larvae inhibited SRP release from sediment. Comparatively, worms inhibited more SRP release than larvae based on the same biomass, as they successively renewed the ferric iron oxyhydroxides rich oxidation layer through their deposition.  相似文献   
186.
聚丙烯酰胺化学降解技术是目前油田含聚污水处理的重要技术之一,包括氧化降解法、光降解法和光催化降解法。文章介绍了此项技术在降解机理和应用方面的研究进展,并通过实验证明了聚丙烯酰胺氧化降解和光降解的可行性,对油田污水中聚丙烯酰胺的化学降解处理具有一定的指导意义。  相似文献   
187.
Ji  Honglu  Tong  Huan  Wang  Jingge  Yan  Dan  Liao  Zangyi  Kong  Ying 《Environmental geochemistry and health》2022,44(9):3115-3132
Environmental Geochemistry and Health - With the expansion of the global novel coronavirus disease (COVID-19) pandemic, unprecedented interventions have been widely implemented in many countries,...  相似文献   
188.
饮用水中挥发性卤代烃的顶空气相色谱分析研究   总被引:2,自引:0,他引:2  
本文研究并拟订了一种饮用水中五种挥发性卤代烃的顶空气相色谱分析法,方法灵敏准确,操作简便快速,实际水样分析结果满意  相似文献   
189.
粪肠球菌是一种在自然环境中广泛存在的革兰氏阳性细菌.由于其特殊的耐药机制及高频率的耐药基因转移方式,导致了环境中耐药粪肠球菌的广泛传播,生态安全形势严峻.其中,信息素应答质粒介导的粪肠球菌耐药基因的接合转移是造成粪肠球菌耐药基因快速扩散的重要方式.本文回顾了近些年关于信息素应答质粒接合转移的研究成果,分析总结了接合转移的必要条件、正负调控信息素对接合转移的调节作用,并以携带四环素抗性的质粒pCF10为例简要探讨了接合转移相关基因、蛋白的调控机制,旨在更加全面地揭示粪肠球菌的耐药基因传播机制,为耐药细菌的基因转移机制研究提供参考.  相似文献   
190.
采用臭氧氧化法对焦化废水(简称废水)进行处理,考察臭氧质量流量和废水pH对废水COD和NH3-N去除率的影响。实验结果表明,在臭氧质量流量为3.6g/h、废水pH为12、反应时间为12h的条件下,废水COD和NH3-N去除率分别为93.74%和74.28%。直接采用臭氧氧化法不能使NH3-N得到较好的去除,采用化学沉淀-臭氧氧化法处理焦化废水后,废水COD、NH3-N、挥发酚和色度的去除率均达97%以上。  相似文献   
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