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141.
为了解决电力环境监测中的数据传输问题,提出了基于ZigBee技术的电力环境监测系统设计方案。该系统通过ZigBee节点采集各种电力环境数据,并将ZigBee网络和GPRS相结合实现远程监测。方案采用TI公司CC2430芯片设计传感器节点电路,在ZigBee协议栈的基础上设计了协调控制器节点,提高了系统的可扩展性,确保了数据传输的实时性和可靠性。 相似文献
142.
María Carmen Carnero Diego J. Pedregal 《Journal of Loss Prevention in the Process Industries》2011,24(4):432-439
A forecasting system is set up to improve the diagnosis in a Condition Monitoring Programme of a critical turbine placed at an industrial plant. The system is based on a statistical model in a State Space framework, such that the local mean level of the vibration state of the equipment is estimated directly from the data, based on a continuous-time set up. This model is combined with a cost model in Conditioned Monitoring, by which the time of preventive replacement is produced when the minimum of the expected cost per unit of time is reached into the future. Such measure is a combination of the costs of failure, the costs of a preventive replacement and the probabilities of reaching the alarm levels fixed by some criteria. The system is estimated by Maximum Likelihood and thoroughly tested on the equipment. The main tests relate to statistical properties of the model residuals and a comprehensive comparison with an alternative system, namely a linear trend regression model in continuous time. The system produced a reasonable forecasting performance and sensible time of preventive replacement prediction and outperformed the alternative forecasting system. 相似文献
143.
为了更精确地反映城市路网交通能耗实际情况,将微观层面的交叉口交通运行与宏观层面的交通网络能源消耗优化结合在一起进行研究,考虑信号控制优化对路网能源消耗的影响,从而实现优化微观的信号控制参数,对宏观的路网能源消耗进行控制。在分析无信号控制交叉口冲突类型的基础上,建立了不同冲突类型下的饱和流率模型,结合排队论理论求解无信号控制交叉口的逗留时间。同时,结合车辆在信号控制交叉口的加减速行为,建立信号控制交叉口的逗留时间模型。同理对信号和无信号控制交叉口的能源消耗量进行建模。综合信号控制和无信号控制交叉口的逗留时间和能源消耗模型,建立路网总能源消耗优化模型,运用Frank-Wolf算法对非线性规划问题进行求解。结合路网各项指标对模型进行分析。结果显示,研究方法相对于传统的定时控制和时间最优信号配时方法均有优势,通过算例应用证明了方法的有效性。 相似文献
144.
目的解决振动信号的加速度、速度、位移三参量全频带测量问题。方法提出一种由振动加速度信号、位移信号生成全频带位移、速度、加速度信号的方法,对实测位移信号微分并低通滤波,对实测加速度信号积分并高通滤波,然后两者相加,得到全频段的加速度、速度、位移信号,所用的微分、积分、滤波都是用离散传函表示。结果不论是正弦振动还是随机振动,生成的位移、速度、加速度信号与正确的位移、速度、加速度信号一致。结论该方法可以由实测位移信号、加速度信号实时生成全频带三参量信号。 相似文献
145.
为探究信号分子联合菌对同步脱氮除硫效果的影响,发现同时投加信号分子和脱氮硫杆菌可以加快硫化物和硝酸盐氮的去除且相比单独投加时更有利于单质硫的稳定积累和氮气产量的增加,并通过FISH技术检测了反应结束后微生物总量,信号联合脱氮硫杆菌可以增加微生物总数,因此能够实现较好地脱氮除硫效果.实验从不同信号分子浓度中找出了有利于单质硫稳定积累的最佳浓度,进而在此浓度下分析了单独投加信号分子、单独投加脱氮硫杆菌,以及同时投加信号分子和脱氮硫杆菌3种情况下的脱氮除硫效果.结果表明,当硫化物浓度为200 mg·L-1时,延长反应时间至72 h后,信号分子联合脱氮硫杆菌使硫化物的去除率提高至99. 8%,硝酸盐去除率提高至96. 9%,且单质硫转化为硫酸盐的速率减慢,氮气的产量增加,反应结束后其单质硫和氮气的量分别达到59. 0 mg和80. 0 m L.当硫化物浓度为300 mg·L-1时,单独投加2. 5μmol·L-1的信号分子在72 h时其硫化物和去除率达到99. 0%,硝酸盐的去除达到93. 9%,单质硫和氮气的产量分别达到63. 1 mg和79. 5 m L. 相似文献
146.
Klaschka Ursula Kolossa-Gehring Marike 《Environmental science and pollution research international》2007,14(1):44-52
Goal, Scope and Background Fragrance preparations or perfumes are used in an increasing variety of applications, as for example washing, cleansing, personal
care products, consumer goods or in applications to modify indoor air. However, up to now, little is known to the general
or scientific public about their chemical identity and the use pattern of single substances, not even for high production
volume chemicals. Some toxicological data are published for a comparatively small number of substances with a focus on sensitisation
and dermal effects, while other effects are neglected. Information on ecotoxicity and environmental fate are rare, especially
for long-term exposure. Data for a detailed hazard and risk analysis are available in exceptional cases only. According to
the current legal situation, fragrance industry is self-regulated, which means that pre-market risk evaluation is not required
for most fragrances.
Odour and the ability to smell play a major role for wildlife for all taxonomic groups. Reproductive and social behaviour,
defence, communication and orientation depend on volatile compounds which can be identical to those used in fragrance preparations.
Our interdisciplinary approach leads to the question of whether and, if so, to what extent anthropogenic fragrances may influence
life and reproduction of organisms in the environment.
Main Features Information from literature on use, exposure and biological effects was combined to analyse the state of knowledge. Following
an overview of the amounts of fragrances used in different consumer products and their release into the environment, the roles
of odours in nature are shown for a selection of compounds. Existing regulation was analysed to describe the data basis for
environmental risk evaluation. Finally, recommendations for further action are derived from these findings.
Results Three main results were elaborated: First, fragrance substances are continuously discharged in large amounts into the environment,
especially via the waste water. Second, there are some indications of negative effects on human health or the environment,
although the data basis is very thin due to the self regulation of the fragrance industry and the regulatory situation of
fragrance substances. Third, many odoriferous substances used by man are identical to those which are signal substances of
environmental organisms at very low concentrations, thus giving rise to specific mode of actions in the ecosystem.
Recommendations For the adequate risk assessments of fragrances, test results on their unspecific as well as their specific effects as signal
substances are needed. This would imply prioritisation methods and development of useful test methods for specific endpoints
for appropriate risk assessments. Before a comprehensive testing and evaluation of results has been finished, a minimization
of exposure should be envisaged. Eco-labelling of products containing acceptable fragrance ingredients could be a first step
and provide consumers with the respective information. Transparency concerning the fragrance ingredients used and their biological
potency will help to build up confidence between producers and consumers.
Conclusions and Perspectives The interdisciplinary approach, bringing together chemical, biological, toxicological and ecotoxicological data with information
provided by manufacturers and with legal and consumer aspects, offers new insights into the field of fragrance substances
used in consumer products. The amounts and application fields of fragrance substances increases while fate and effects in
the environment are hardly known. The current legal situation is not suited to elucidate the effects of fragrances on human
health and the environment sufficiently, especially as it was shown that fragrances may play a considerable role in the ecosystem
on the behaviour of organisms. According to the precautionary principle, the lack of knowledge should best be tackled by reducing
exposure, especially for compounds such as fragrance substances where no ethical reasons object a substitution by less hazardous
chemicals.
ESS-Submission Editor: Dr. Thomas Knacker (th-knacker@ect.de) 相似文献
147.
本文利用电磁波观测台的实测资料,对宁蒗Ms5.1级、会泽Ms4.4级地震前电磁波异常信号特征、干扰排除、异常判别进行研究,分析了震前电磁波信号图象和异常时空特征,得出电磁波主信号异常出现在主震前20天左右的结论。 相似文献
148.
Mathieu Troïanowski Nathalie Mondy Adeline Dumet Caroline Arcanjo Thierry Lengagne 《Conservation biology》2017,31(5):1132-1140
During the last decade, many studies have focused on the detrimental effects of noise pollution on acoustic communication. Surprisingly, although it is known that noise exposure strongly influences health in humans, studies on wildlife remain scarce. In order to gain insight into the consequences of traffic noise exposure, we experimentally manipulated traffic noise exposure as well as the endocrine status of animals to investigate physiological and phenotypic consequences of noise pollution in an anuran species. We showed that noise exposure increased stress hormone level and induced an immunosuppressive effect. In addition, both traffic noise exposure and stress hormone application negatively impacted H. arborea vocal sac coloration. Moreover, our results suggest profound changes in sexual selection processes because the best quality males with initial attractive vocal sac coloration were the most impacted by noise. Hence, our study suggests that the recent increases in anthropogenic noise worldwide might affect a broader range of animal species than previously thought, because of alteration of visual signals and immunity. Generalizing these results to other taxa is crucial for the conservation of biodiversity in an increasingly noisy world. 相似文献
149.
150.