Organic nitrates are secondary atmospheric pollutants that play a key role in ozone and aerosol production. This study focused on the simulation of organic nitrates through a box model coupled with RACM2 （Regional At...Organic nitrates are secondary atmospheric pollutants that play a key role in ozone and aerosol production. This study focused on the simulation of organic nitrates through a box model coupled with RACM2 （Regional Atmospheric Chemistry Mechanism, version 2）, based on data from the PRIDE-PRD2006 campaign in Backgarden, China. Our study found that an overestimation of organic nitrate production rate was generated by the model. Furthermore, the effective production ratio （a^ff） of organic nitrates was around 0.033 after optimizing its chemical production module. The chemical impacts of organic nitrates on ozone production were related to VOC-OH reactivity and aeff. We found that VOC-OH reactivity was positively related to aeff, resulting in the suppression of ozone production caused by organic nitrates, which showed that P（Ox=O3＋NO2） increased initially and subsequently decreased with VOC-OH reactivity. These results highlight the importance of organic nitrate＇s impact on ozone production in strategies to control ozone pollution, specifically regarding the reduction of low-molecular-weight VOCs in the Pearl River Delta.展开更多
Organisms often evolve behaviours that increase or reinforce the protection from predators afforded by their morpho- logical defences. For example, mimetic animals may adopt postures or locomotory behaviours that emul...Organisms often evolve behaviours that increase or reinforce the protection from predators afforded by their morpho- logical defences. For example, mimetic animals may adopt postures or locomotory behaviours that emulate a characteristic fea- ture of their model to increase predator deception. Caterpillars with eyespots are thought to mimic snakes, and when threatened many of these caterpillars adopt a posture that appears to enhance this resemblance. Herein we evaluate the quantitative strength of evidence of behavioural mimicry in the caterpillars of 14 species by comparing how closely a series of putative snake-mimicking caterpillars resemble snakes while at rest and when threatened. Specifically, we quantified the head morphology and eye position of a range of snake species, as well as the shape of the apparent head （i.e. anterior body segments） and position of eyespots in caterpillars resting or in their defensive posture. This allowed us to objectively examine evidence for an increased resemblance to either snakes generally, or to Viperidae snakes specifically, upon adopting the defensive posture. Widening the anterior body segments during the defensive posture typically made caterpillars appear more viper-like as opposed to more snake-like in general. Enhanced resemblance to vipers upon mounting the defensive posture was apparent only from the dorsal view. Laterally, caterpillars more closely resembled snakes in the resting posture and shifting to the defensive posture instead reduced mimetic fidelity, Overall we found evidence for behavioural mimicry in all 14 species examined. We highlight that objectively quantifying mimetic fidelity can help identify key features involved in deception .展开更多
Organic Rankine Cycles(ORCs) are an effective way to produce electricity from low-grade heat sources, which cannot be effectively obtained using conventional high-temperature Rankine cycles. Due to the lack of availab...Organic Rankine Cycles(ORCs) are an effective way to produce electricity from low-grade heat sources, which cannot be effectively obtained using conventional high-temperature Rankine cycles. Due to the lack of available information regarding the real Organic Rankine Cycle units on industrial level, off-design simulation under diversified operating conditions plays a significant role for both the system performance prediction and control strategy design. This paper summarizes the theoretical basis, modeling approaches and tools for ORC off-design simulations. Firstly, a review was conducted on the individual state-of-the-art convective heat transfer correlations and void fraction models. Secondly, different kinds of modeling approaches and simulation tools were proposed, highlighting their relevant characteristics, and were categorized for their specific applications. Moreover, an in-depth analysis of technical challenges related to various applications and focusing on the model accuracy and complexity, computational efficiency, as well as the model compatibility were extensively described and discussed. Finally, the current research trends in this field and the development for further investigations were presented.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 41375124, 21522701,91544225, and 41421064)the Strategic Priority Research Program of the China Academy of Sciences (Grant No. XDB05010500)+2 种基金the Doctoral Fund of Ministry of Education of China (Grant No. 20130001120010)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No. 2014BAC21B01)the Commonwealth Project of the Ministry of Environmental Protection (Grant No. 201409005)
文摘Organic nitrates are secondary atmospheric pollutants that play a key role in ozone and aerosol production. This study focused on the simulation of organic nitrates through a box model coupled with RACM2 （Regional Atmospheric Chemistry Mechanism, version 2）, based on data from the PRIDE-PRD2006 campaign in Backgarden, China. Our study found that an overestimation of organic nitrate production rate was generated by the model. Furthermore, the effective production ratio （a^ff） of organic nitrates was around 0.033 after optimizing its chemical production module. The chemical impacts of organic nitrates on ozone production were related to VOC-OH reactivity and aeff. We found that VOC-OH reactivity was positively related to aeff, resulting in the suppression of ozone production caused by organic nitrates, which showed that P（Ox=O3＋NO2） increased initially and subsequently decreased with VOC-OH reactivity. These results highlight the importance of organic nitrate＇s impact on ozone production in strategies to control ozone pollution, specifically regarding the reduction of low-molecular-weight VOCs in the Pearl River Delta.
文摘Organisms often evolve behaviours that increase or reinforce the protection from predators afforded by their morpho- logical defences. For example, mimetic animals may adopt postures or locomotory behaviours that emulate a characteristic fea- ture of their model to increase predator deception. Caterpillars with eyespots are thought to mimic snakes, and when threatened many of these caterpillars adopt a posture that appears to enhance this resemblance. Herein we evaluate the quantitative strength of evidence of behavioural mimicry in the caterpillars of 14 species by comparing how closely a series of putative snake-mimicking caterpillars resemble snakes while at rest and when threatened. Specifically, we quantified the head morphology and eye position of a range of snake species, as well as the shape of the apparent head （i.e. anterior body segments） and position of eyespots in caterpillars resting or in their defensive posture. This allowed us to objectively examine evidence for an increased resemblance to either snakes generally, or to Viperidae snakes specifically, upon adopting the defensive posture. Widening the anterior body segments during the defensive posture typically made caterpillars appear more viper-like as opposed to more snake-like in general. Enhanced resemblance to vipers upon mounting the defensive posture was apparent only from the dorsal view. Laterally, caterpillars more closely resembled snakes in the resting posture and shifting to the defensive posture instead reduced mimetic fidelity, Overall we found evidence for behavioural mimicry in all 14 species examined. We highlight that objectively quantifying mimetic fidelity can help identify key features involved in deception .
基金financially supported by the National Key Basic Research Program of China 973 Program(Grant No.2014CB249201)
文摘Organic Rankine Cycles(ORCs) are an effective way to produce electricity from low-grade heat sources, which cannot be effectively obtained using conventional high-temperature Rankine cycles. Due to the lack of available information regarding the real Organic Rankine Cycle units on industrial level, off-design simulation under diversified operating conditions plays a significant role for both the system performance prediction and control strategy design. This paper summarizes the theoretical basis, modeling approaches and tools for ORC off-design simulations. Firstly, a review was conducted on the individual state-of-the-art convective heat transfer correlations and void fraction models. Secondly, different kinds of modeling approaches and simulation tools were proposed, highlighting their relevant characteristics, and were categorized for their specific applications. Moreover, an in-depth analysis of technical challenges related to various applications and focusing on the model accuracy and complexity, computational efficiency, as well as the model compatibility were extensively described and discussed. Finally, the current research trends in this field and the development for further investigations were presented.
