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41.
介绍了气体样品的各种保存方法及其在保存过程中成分变化的特点,以降低气体保存过程中的损失,提高监测管理水平。  相似文献   
42.
Rost H  Loibner AP  Hasinger M  Braun R  Szolar OH 《Chemosphere》2002,49(10):1239-1246
The stability of historically polycyclic aromatic hydrocarbon (PAH)-contaminated soils during cold storage was investigated. Samples from two former manufactured gas plants exhibited quantitative recoveries of PAHs over the whole period of sample holding at 4 °C in the dark (8–10 months), whereas significant losses of PAHs were observed for soils received from a former railroad sleeper preservation plant with low molecular weight compounds being notably more affected compared to heavier PAHs. Already after 2 weeks of holding time, 3-ring PAHs in one of theses samples were down to 29–73% of the initial concentration and significant losses were observed for up to 5-ring compounds. Dissipation of PAHs was found to be predominantly due to aerobic microbial metabolism since sodium azide poisoned samples showed quantitative recoveries for all PAHs over the entire storage time of 3 months. A similar stabilizing effect was observed for freezing at −20 °C as means of preservation. Except for acenaphthene, no significant loss for any of the PAHs was observed over 6 weeks of holding time. Eventually, selected chemical, physical, and biological parameters of two soils were investigated and identified as potential indicators for the stability of PAH-contaminated soil samples.  相似文献   
43.
采用神经网络技术对松江污水厂污水处理活性污泥系统进行建模试验研究,在对实际运行数据按机理准则和范围准则剔除异常数据后,将样本数据随机分成训练样本、检验样本和测试样本。用试凑法确定合理的神经网络隐层节点数,以避免采用过大或过小的网络结构,在训练过程中用检验样本实时监控从而避免“过训练”现象的影响,较好地解决神经网络方法建模的两大难题,从而建立可靠、有效的活性污泥系统神经网络模型。并应用建立的网络模型对活性污泥系统的运行情况进行了仿真研究。建模研究表明,神经网络技术能较好地应用于活性污泥系统的建模,模型具有较好的泛化能力,有很好的实用价值。  相似文献   
44.
本文认为,如果能将“毛泽东思想概论”这一课程名分解为“毛泽东”“毛泽东思想”“毛泽东思想概论”3个概念,并逐一进行总体性、概括性讲解,对上好(《毛泽东思想概论》第一课,很有帮助。  相似文献   
45.
戴泳 《干旱环境监测》1994,8(3):173-175,183
应用数理统计中抽样理论,对瑞安市环境噪声监测点进行了优化组合,方法简单易行,兼顾了功能区特征,减少了测点数,并能达到要求的准确性。  相似文献   
46.
本文研究了三溴偶氮肿(TBA)与钙、镁的显色反应,结果表明:在平平加存在下,PH10.4硼酸-氢氧化钠缓冲体系中,钙、镁与TBA都形成1:2稳定的紫色络合物,以490nm为参比波长,620nm为测定波长,用双波长分光光度法测得ε_(490-620)~(Ca)=7.21×10~3l·mol~(-1)·cm~(-1),ε_(490-620)~(Ca)=2.55×10~4l·mol~(-1)·cm~(-1),比尔定律范围是0-35μgmg/25ml,0-40μgCa/25ml,无平平加时ε_(490-620)~(Mg)=6.61×10~3l·mol~(-1)·cm~(-1),ε_(490-620)~(Ca)=2.3×10~4。根据有无平平加时测定络合物吸光度的差异,利用公式法求得Ca,Mg含量,方法简便、快速、可靠。  相似文献   
47.
环境监测实验室样品管理是质量管理的重要环节,样品管理的智能化、信息化将大幅提升实验室的管理水平。通过分析当前监测实验室样品管理现状和不足,借鉴相关行业样品智能物流管理系统应用经验,结合江苏省环境监测中心新建的监测实验大楼,开展环境监测样品智能物流管理系统设计研究。提出,考虑环境监测样品接收、任务分配、样品交接、样品留存各个环节,以样品属性为基准进行样品管理系统设计;同时,结合物联网集成管控、气动传输和机器人输送技术,构建包含分布式存储工作站和密集型土壤样品库的样品智能物流管理系统,实现高效、智能、规范的样品管理目标。  相似文献   
48.
The fauna of deep-sea hydrothermal vents are among the most isolated and inaccessible biological communities on Earth. Most vent sites can only be visited by subsea vehicles, which can and do move freely among these communities. Researchers assume individuals of the regionally homogeneous vent fauna are killed by the change in hydrostatic pressure the animals experience when the subsea vehicles, which collected them, rise to the surface. After an Alvin dive, we found 38 apparently healthy individuals of a vent limpet in a sample from a hydrothermally inactive area. Prompted by our identification of these specimens as Lepetodrilus gordensis, a species restricted to vents 635 km to the south of our dive site, we tested whether they were from a novel population or were contaminants from the dive made 36 h earlier. The 16S gene sequences, morphology, sex ratio, bacterial colonies, and stable isotopes uniformly indicated the specimens came from the previous dive. We cleaned the sampler, but assumed pressure changes would kill any organisms we did not remove and that the faunas of the 2 areas were nearly identical and disease-free. Our failure to completely clean the gear on the subsea vehicle meant we could have introduced the species and any diseases it carried to a novel location. Our findings suggest that the nearly inaccessible biological communities at deep-sea vents may be vulnerable to anthropogenic alteration, despite their extreme physical conditions.  相似文献   
49.
刍议环境监测在环境保护工作中的作用研究   总被引:1,自引:0,他引:1  
随着中国社会主义市场经济的进步和发展,人们的环保意识日渐增加,对环境保护工作的要求越来越高。为了提升环境保护工作的质量,必须要大力发展环境的监测技术。因为环境监测是环境保护工作中的重要组成部分,其作用主要是全面、及时、准确的反映当前环境的质量以及环境问题的发展趋势,为人类的环境保护工作提供科学的依据。鉴于环境监测的重要性,中国环保单位必须要高度重视环境监测技术的研究和发展,提高环境监测的效率和质量。  相似文献   
50.
Despite differences in focus, goals, and strategies between conservation biology and animal welfare, both are inextricably linked in many ways, and greater consideration of animal welfare, although important in its own right, also has considerable potential to contribute to conservation success. Nevertheless, animal welfare and animal ethics are not always considered explicitly within conservation practice. We systematically reviewed the recent scientific peer‐reviewed and online gray literature on reintroductions of captive‐bred and wild‐caught animals (mammals, birds, amphibians, and reptiles) to quantify the occurrence of animal welfare issues. We considered monitoring that could be indicative of the animal's welfare status and supportive management actions that could improve animal welfare (regardless of whether the aim was explicitly animal‐welfare orientated). Potential welfare issues (of variable nature and extent) were recorded in 67% of 199 projects reviewed; the most common were mortality >50%, dispersal or loss of animals, disease, and human conflict. Most (>70%) projects monitored survival, 18% assessed body condition, and 2% monitored stress levels. Animal welfare, explicitly, was referred to in 6% of projects. Supportive actions, most commonly use of on‐site prerelease pens and provision of supplemental food or water, were implemented in 79% of projects, although the extent and duration of support varied. Practitioners can address animal‐welfare issues in reintroductions by considering the potential implications for individual animals at all stages of the release process using the decision tree presented. We urge practitioners to report potential animal‐welfare issues, describe mitigation actions, and evaluate their efficacy to facilitate transparent evaluation of common moral dilemmas and to advance communal strategies for dealing with them. Currently, comparative mortality rates, health risks, postrelease stress, effectiveness of supportive measures, and behavior of individuals warrant further research to improve animal welfare in reintroductions and to increase success of such projects. Ética Conflictiva y Complementaria al Considerar el Bienestar Animal en Reintroducciones  相似文献   
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