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Teruhiko Takahara Yukihiro Kohmatsu Atsushi Maruyama Ryohei Yamaoka 《Behavioral ecology and sociobiology》2008,63(2):235-240
When predator chemical cues are present, low activity of prey is a commonly seen defensive behavior. However, few studies
have explored the functional implications of the defensive behaviors and, thus, elucidated the possible linkages between behavioral
responses and its consequences. In this study, we experimentally investigated how behavioral responses of Hyla japonica tadpoles to predator chemical cues affect vulnerability to a dragonfly nymph Anax parthenope julius. The frequency of tadpoles attacked by dragonfly nymphs was lower with chemical cues of predator was present than without
chemical cues, and most of attacks occurred when tadpoles were mobile. When tadpoles were exposed to chemical cues, on the
other hand, their swimming speed was quicker and swimming distance was longer, respectively, and the rates of being approached
of the swimming tadpoles by dragonfly nymph was lower than those not exposed to chemical cues. We found that the tadpoles
are induced by predator chemical cues not only to generally lower activity but also to swim in bursts as additional behavior
and that the suite of their behavioral responses reduce the vulnerability against dragonfly nymph. Tadpoles can receive information
about the predation risks by chemical cues and adjust their defensive behavior accordingly. 相似文献
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基于气相色谱仪 (GC)和电子捕获检测器 (ECD) ,设计了一种连续测量大气中痕量氯氟烃的自动系统。系统色谱基线稳定 ,分离效果好 ,定性、定量准确可靠 ,系统高度自动化 ,长期运行无需人值守 ,自动校正数据 ,定时进行严格的质量控制 ;系统具有较高的现场测量频率 (6次 /h) ,改进的反吹 /外切设计使CFCs色谱峰不再受氧峰的干扰 ,大大延长了检测器的寿命 ,使长期连续观测成为可能。系统设计在分离效果方面优于世界气象组织 (WMO)全球大气监测网 (GAW )目前所使用的测量大气本底CFCs的方法 ,采用美国EPA认可的标气 ,外标工作曲线法测定大气CFCs的浓度 ,最低检测限可达1pL/L ,检测精密度小于 1 % ,准确度在± 3%之内 ,可用于我国本底大气观测站对CFCs的连续测定 相似文献
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为提高古建筑修缮阶段火灾监测水平,有效预防火灾事故,提出1种基于YOLO-BP神经网络算法的古建筑修缮阶段火灾监测模型。针对修缮作业对古建筑产生的消防隐患,在施工场地设置监测点,并利用YOLO算法以火源、可燃物为目标进行检测与定位,计算火源与可燃物距离;以火源温度、含氧量、火源与可燃物距离3项指标作为BP神经网络输入层,以火灾概率为输出层,从而进行预测;基于古建筑修缮阶段焊接、切割动火作业阶段的样本数据进行仿真模拟。结果表明:利用模型监测古建筑修缮阶段火灾的准确率达93.9%,验证模型的可靠性;当火源温度在150~2 000 ℃范围内,含氧量不小于19.5%时,动火作业安全距离为10.1 m。 相似文献
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利用Hach仪器开发低浓度COD的测试方法 总被引:4,自引:1,他引:3
利用Hach仪器开发了0 mg/L~150 mg/L COD的测试方法.采用反应器消解,比色法测定,配制的消解液能保证样品消解过程中浓硫酸和催化剂的含量与国标法相当,通过150 mg/L COD样品消解结束后重铬酸根离子半电池反应的电位折中确定重铬酸钾浓度.校准曲线线性关系良好,方法检出限为7 mg/L,与国标法作比较,结果表明两种方法可替换使用. 相似文献
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低浓度SO2和NOx 自动监测系统性能评价方法 总被引:1,自引:0,他引:1
通过对7种废气自动监测系统的比较研究和现场测试,提出了非分散红外法、紫外差分法、紫外荧光法、化学发光法等多种 SO2和 NO x 自动监测技术在低浓度范围实现准确定量监测的性能评价方法,定义了 CEMS 的系统检出限及其主要影响因素。建议采用系统检出限、线性误差等关键参数作为低浓度 CEMS 的性能评价方法,提出将全系统多点标准气体校准或加标回收率作为验收和质控监督的基本方法。 相似文献
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Amos A. de JongAuthor Vitae Piety R. RunhaarAuthor Vitae 《Environmental Impact Assessment Review》2012,33(1):23-31
A growing number of low and middle income nations (LMCs) have adopted some sort of system for environmental impact assessment (EIA). However, generally many of these EIA systems are characterised by a low performance in terms of timely information dissemination, monitoring and enforcement after licencing. Donor actors (such as the World Bank) have attempted to contribute to a higher performance of EIA systems in LMCs by intervening at two levels: the project level (e.g. by providing scoping advice or EIS quality review) and the system level (e.g. by advising on EIA legislation or by capacity building). The aims of these interventions are environmental protection in concrete cases and enforcing the institutionalisation of environmental protection, respectively. Learning by actors involved is an important condition for realising these aims. A relatively underexplored form of learning concerns learning at EIA system-level via project level donor interventions. This ‘indirect’ learning potentially results in system changes that better fit the specific context(s) and hence contribute to higher performances. Our exploratory research in Ghana and the Maldives shows that thus far, ‘indirect’ learning only occurs incidentally and that donors play a modest role in promoting it. Barriers to indirect learning are related to the institutional context rather than to individual characteristics. Moreover, ‘indirect’ learning seems to flourish best in large projects where donors achieved a position of influence that they can use to evoke reflection upon system malfunctions. In order to enhance learning at all levels donors should thereby present the outcomes of the intervention elaborately (i.e. discuss the outcomes with a large audience), include practical suggestions about post-EIS activities such as monitoring procedures and enforcement options and stimulate the use of their advisory reports to generate organisational memory and ensure a better information dissemination. 相似文献