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21.
环境污染源监测中的警示性分析 总被引:1,自引:0,他引:1
利用概率论有关知识,对污染源监测数据进行处理、分析、建立数字模型。依该模型可即时捕捉发生环境污染的警示性信号。 相似文献
22.
Yanjun Chang Faisal Khan Salim Ahmed 《Process Safety and Environmental Protection》2011,89(5):310-316
Alarm flooding is a major safety issue in today's processing facilities. Important recommendations are available for alarm management; however, they are often violated in practice, especially in the alarm systems implemented through the distributed control system. An effective process alarm prioritization and management system is desired for a safe and effective operation of a process facility.In present work, authors address two main issues related to an alarm system – the reliability and the prioritization of the alarms. The main objective is to deal with the alarm-flooding problem in process facilities. A multi alert voting system based on sensor redundancy approach is proposed to improve the reliability. A quantitative risk-based alarm management approach is proposed to address the flooding issue. In the risk-based approach, an integrated model consisting of the probability (P), the impact (I) of the potential hazards, and the process safety time is proposed to prioritize these raised alarms.The proposed approach is further explained by a reactor system with pressure and temperature variable monitoring and controls, where the hazards associated with two alerts caused by over high pressure and over high temperature are analyzed and integrated with response time for alarms generation and prioritization. 相似文献
23.
Summary. Many aquatic species use chemosensory information to assess predation risk. The cues used in such risk assessment can come
either from the predator (predator odour) or from injured prey (alarm cues). The information conveyed through chemicals may,
however, be inaccurate both spatially and temporally, as chemicals may persist in the environment long after the predator
is gone. Thus, the level of accuracy of the cues for risk assessment may depend on the persistency of the chemicals in the
habitat. Here, we investigated the persistency of alarm cues of a larval amphibian, the woodfrog (Rana sylvatica) in a ephemeral pond, their natural habitat. We introduced either alarm cues or control water in enclosed sleeves (~10 L)
installed in the pond. The sleeve water was then sampled after 5 min and every two hours for eight hours. We used the behavioural
response of woodfrog tadpoles to alarm cues as a bioassay to assess how long the alarm cues persisted in the environment.
We found that tadpoles responded with an antipredator response to the pond water containing alarm cues 5 min after the injection
of the cues in the sleeves but did not respond to that same pond water after two hours. Our results indicate that biodegradation
and/or photodegradation of alarm cues in natural habitats might occur relatively quickly as the loss of a response to the
cues in our experiment was independent of a dilution effect. This contrasts with previous laboratory results indicating that
chemicals may be active after several hours. 相似文献
24.
Summary. While the response to damage-released chemical alarm cues within the superorder Ostariophysi appears to be highly conserved
across species, it is generally observed that the intensity of response to heterospecific alarm cues decreases with increasing
phylogenetic distance. Recent studies have demonstrated that purine-N-oxides function as chemical alarm cues within Ostariophyian fishes and that the nitrogen-oxide functional group is conserved
as the chief molecular trigger. According to the purine-ratio hypothesis, these cross-species differences may be due to the
relative proportion of different carrier compounds associated with the nitrogen-oxide molecular trigger. To test this hypothesis,
we exposed glowlight tetras (Hemigrammus erythrozonus, Characidae, Ostariophysi) to one of five synthetic stimuli (hypoxanthine-3-N-oxide (H3NO), pyridine-N-oxide (PNO) or mixed stimuli of 75 % H3NO-25 % PNO, 50 % H3NO-50 % PNO, or 25 % H3NO-75 % PNO), natural conspecific chemical
alarm cue or a distilled water control. We quantified changes in shoal cohesion and vertical area use as species typical indicators
of an antipredator response. As predicted, response intensity decreased as the ratio of hypoxanthine-3-N-oxide to pyridine-N-oxide decreased and the strongest response was to natural alarm cue. These results suggest that species-specific carrier
compounds may account for the well-documented cross-species differences in the response to heterospecific alarm cues within
phylogenetically related taxa. 相似文献
25.
Linda I. Hollén Tim Clutton-Brock Marta B. Manser 《Behavioral ecology and sociobiology》2008,62(5):821-829
In many species, individuals suffer major mortality in their first year because of predation. Behaviours that facilitate successful
escape are therefore under strong selection, but anti-predator skills often emerge gradually during an individual’s early
development. Using long-term data and acoustic recordings of alarm calls collected during natural predator encounters, we
aimed to elucidate two largely unsolved issues in anti-predator ontogeny: (1) whether incorrect predator assignment is adaptively
age-appropriate, given that vulnerability often changes during development, or whether age-related differences reflect true
mistakes made by immature individuals; and (2) the extent to which the development of adult-like competence in alarm-call
production and usage is simply a function of maturational processes or dependent upon experience. We found that young meerkats
(Suricata suricatta) were less likely to give alarm calls than adults, but alarmed more in response to non-threatening species compared to adults.
However, stimuli that pose a greater threat to young than adults did not elicit more calling from young; this argues against
age-related changes in vulnerability as the sole explanation for developmental changes in calling. Young in small groups,
who were more likely to watch out for predators, alarmed more than less vigilant young in larger groups. Moreover, despite
similarities in acoustic structure between alarm call types, calls appeared in the repertoire at different rates, and those
that were associated with frequently encountered predators were produced relatively early on. These results indicate that
experience is a more plausible explanation for such developmental trajectories than maturation. 相似文献
26.
Kleptoparasitism is a tactic used to acquire food opportunistically and has been shown to provide several benefits, including
greater food intake rate and the acquisition of items not normally available during self-foraging. Host individuals may differ
in their ability to defend themselves against kleptoparasitic attacks and therefore identifying those host individuals that
are particularly vulnerable to attack could both provide energetic benefits and increase the efficiency of kleptoparasitism
as a foraging strategy. Here, we show that the kleptoparasitic fork-tailed drongo (Dicrurus adsimilis) specifically targets juveniles when following groups of cooperatively breeding pied babblers (Turdoides bicolor). Drongos give alarm calls upon sighting a predator, thus providing extra predator vigilance to foraging pied babblers. However,
drongos also use alarm calls to steal food items. During kleptoparasitic attacks, drongos give false alarm calls and then
swoop down to steal food items dropped by alarmed babblers. Juvenile pied babblers are particularly vulnerable to attack because
they (a) spend a longer period handling prey items prior to consumption and (b) respond to alarm calls primarily by immediately
moving to cover, in contrast to adults who respond by looking up and visually scanning the surrounding area. Drongos attack
juvenile babblers significantly more often than adults, with attacks on juveniles more likely to result in the successful
procurement of a food item. This patterns of attack suggests that drongos are able to differentiate between individuals of
different age when targeting pied babblers, thus increasing the efficiency of kleptoparasitism as a foraging strategy. 相似文献
27.
Intensive study of arboreal forest-dwelling primates and their predators in Africa is increasingly revealing that crowned
eagles (Stephanoaetus coronatus) are major predators of primates. Gray-cheeked mangabeys (Lophocebus albigena) are overrepresented in the diets of crowned eagles in Kibale National Park, Uganda, and adult male mangabeys are represented
more than females. We focused on the behavior of adult male gray-cheeked mangabeys living in social groups in Kibale National
Park (1) to clarify the interactions between mangabeys and eagles that might put adult males at greater risk and (2) to better
understand individual variation in behavioral responses to predators. Adult male mangabeys in five groups responded to observer-confirmed
presence of crowned eagles 88 times over a 13-month period. While all males gave alarm calls, only the highest-ranking male
in each of four groups chased eagles. These males had elevated levels of fecal cortisol metabolites in the days immediately
after they engaged in active defense, suggesting that they perceived such behavior as risky. In the one group where male ranks
were unstable and there were no infants, no male was observed to chase eagles. We suggest that males pursue the dangerous
tactic of chasing eagles only when they are likely to have offspring in the group. Males in larger groups also spent less
time alarm calling to crowned eagles (from first to last call in a group), and our observations confirmed that the duration
of their alarm calls was related to eagle presence. Thus, eagles spent less time around larger mangabey groups. Alarm calling
by adult male mangabeys may signal to this ambush predator that it has been detected and should move on. 相似文献
28.
《Process Safety and Environmental Protection》2014,92(5):406-411
Management of a plant alarm system has been identified as one of the key safety issues because of disasters caused by alarm floods. When a chemical plant is at abnormal state, an alarm system must provide useful information to operators as the third layer of an independent protection layer (IPL). Therefore, a method of designing a plant alarm system is important for plant safety. Because the plant is maintained in the plant lifecycle, the alarm system for the plant should be properly managed through the plant lifecycle. To manage changes, the design rationales of the alarm system should be explained explicitly. This paper investigates a logical and systematic alarm system design method that explicitly explains the design rationales from know-why information for proper management of changes through the plant lifecycle. In the method, the module structure proposed by Hamaguchi et al. (2011) to assign a fault origin to be distinguished is extended. Using modules to investigate the sets of alarm sensors and the alarm limits setting for first alarm alternative signals to distinguish the fault origin, an alarm system design method is proposed. Also, the completeness of fault propagation for a branch of the cause–effect model as the plant model is explained. Using the modules and the set of fault origins to be distinguished by the alarm system, we try to explicitly explain the design rationales of the alarm system. 相似文献
29.
随着我国公路交通量日益增多,大断面、特大断面公路隧道不断涌现,可靠、有效的隧道火灾探测越来越重要。选取了6种典型的隧道断面,综合考虑探测器类型、纵向风速、火源功率、火源位置等因素,运用火灾动力学模拟软件FDS分析了系列火灾场景下温度、烟气分布、探测器报警时间、报警位置偏移量等特性。研究结果表明: 隧道断面尺寸、纵向风速越大,感温探测器报警时间越长。通过对顶棚烟气温度的分析,发现特大断面隧道中线型感温探测系统采用差温报警较定温报警更有效。在使用差温报警时,纵向通风会使报警位置发生偏移,报警位置偏移量d与隧道纵向风速v、火源到隧道顶棚距离Hd满足线性关系式:d=6.404v+0.923Hd-6.762。随着隧道断面尺寸的增大,需要敷设更多的感温光纤以在规定时间(60 s)内探测到火灾。对于高度H≥12 m的隧道,即使增设多条感温光纤,也无法在60 s内有效报警,需补充设置基于火焰和烟气特征的非接触式火灾探测器。 相似文献
30.
随着中国森林的过度砍伐,森林面积急剧减少,对植被的保护刻不容缓。但由于人力物力有限,无法对大量的野生植被进行实时巡视,造成大量野生植被的滥砍滥伐。采用数字摄像头作为采集终端,利用太阳能电池作为可移动电源,结合 GPS 和 GSM的智能控制板,实现植被状况的前端智能判断与实时监控。 相似文献