Several food companies are implementing effective strategies to evaluate the environmental impacts of their products or processes and to estimate the greenhouse gases emissions （GHG） using a life cycle approach. Par...Several food companies are implementing effective strategies to evaluate the environmental impacts of their products or processes and to estimate the greenhouse gases emissions （GHG） using a life cycle approach. Particularly, a sector which can play an important role to reduce the impact on the environment through the life cycle thinking is the beverage packaging. In this context, the aim of this study was to use the life cycle assessment （LCA） method to investigate the consistency of the preference order across two alternative beverage packages through the application of two impact assessment methods, namely the IPCC 2007 which is focused on the GHG emissions estimation and the EcoIndicator 99 which considers several environmental categories including impact on climate change. The results showed that the life cycle approach employment was a useful strategy to investigate the consistency of the preference order across two beverage packages, especially, whether the results are made more reliable by the utilization of primary data. The investigation on climate change conducted on two level, initially, the quantification of the GHG emissions and secondly the estimation of the related diseases and mortality, demonstrated that the laminated carton presents lower impacts than the high-density polyethylene （HDPE） bottle.展开更多
Coordination to form polymer is emerging as a new technology for modifying or enhancing the properties of the existed energetic substances in energetic materials area. In this work, guanidine cation CN3 H6+ (Gu) and 3...Coordination to form polymer is emerging as a new technology for modifying or enhancing the properties of the existed energetic substances in energetic materials area. In this work, guanidine cation CN3 H6+ (Gu) and 3-amino-1,2,4-triazole C2H4N4(ATz) were crystallized into NaN5 and two novel energetic coordination polymers(CPs),(NaN5)5[(CH6-N3)N5](N5)3–(1) and(NaN5)2(C2H4N4)(2) were prepared respectively via a self-assembly process. The crystal structure reveals the co-existence of the chelating pentazole anion and organic component in the solid state. In polymer 1, Na+and N5– were coordinated to form a cage structure in which guanidine cation [C(NH2)3]+ was trapped;for polymer 2, a mixedligand system was observed;N5 – and ATz coordinate separately with Na+and form two independent but interweaved nets. In this way, coordination polymer has been successfully utilized to modify specific properties of energetic materials through crystallization. Benefiting from the coordination and weak interactions, the decomposition temperatures of both polymers increase from 111°C(1D structure [Na(H2 O)(N5)]?2 H2 O) to 118.4 and 126.5°C respectively. Moreover, no crystallized H2 O was generated in products to afford the anhydrous compounds of pentazole salts with high heats of formation( >800 kJ mol–1). Compared to traditional energetic materials, the advantage in heats of formation is still obvious for the cyclo-N5– based CPs, which highlights cyclo-N5– as a promising energetic precursor for high energy density materials(HEDMs).展开更多
Deposition of clean and defect-free atomically thin two-dimensional crystalline flakes on surfaces by mechanical exfoliation of layered bulk materials has proven to be a powerful technique, but it requires a fast, rel...Deposition of clean and defect-free atomically thin two-dimensional crystalline flakes on surfaces by mechanical exfoliation of layered bulk materials has proven to be a powerful technique, but it requires a fast, reliable and non-destructive way to identify the atomically thin flakes among a crowd of thick flakes. In this work, we provide general guidelines to identify ultrathin flakes of TaSe2 by means of optical microscopy and Raman spectroscopy. Additionally, we determine the optimal substrates to facilitate the optical identification of atomically thin TaSe2 crystals. Experimental realization and isolation of ultrathin layers of TaSe2 enables future studies on the role of the dimensionality in interesting phenomena such as superconductivity and charge density waves.展开更多
文摘Several food companies are implementing effective strategies to evaluate the environmental impacts of their products or processes and to estimate the greenhouse gases emissions （GHG） using a life cycle approach. Particularly, a sector which can play an important role to reduce the impact on the environment through the life cycle thinking is the beverage packaging. In this context, the aim of this study was to use the life cycle assessment （LCA） method to investigate the consistency of the preference order across two alternative beverage packages through the application of two impact assessment methods, namely the IPCC 2007 which is focused on the GHG emissions estimation and the EcoIndicator 99 which considers several environmental categories including impact on climate change. The results showed that the life cycle approach employment was a useful strategy to investigate the consistency of the preference order across two beverage packages, especially, whether the results are made more reliable by the utilization of primary data. The investigation on climate change conducted on two level, initially, the quantification of the GHG emissions and secondly the estimation of the related diseases and mortality, demonstrated that the laminated carton presents lower impacts than the high-density polyethylene （HDPE） bottle.
基金financially supported by the National Natural Science Foundation of China (11702141, 21771108, and U1530101)
文摘Coordination to form polymer is emerging as a new technology for modifying or enhancing the properties of the existed energetic substances in energetic materials area. In this work, guanidine cation CN3 H6+ (Gu) and 3-amino-1,2,4-triazole C2H4N4(ATz) were crystallized into NaN5 and two novel energetic coordination polymers(CPs),(NaN5)5[(CH6-N3)N5](N5)3–(1) and(NaN5)2(C2H4N4)(2) were prepared respectively via a self-assembly process. The crystal structure reveals the co-existence of the chelating pentazole anion and organic component in the solid state. In polymer 1, Na+and N5– were coordinated to form a cage structure in which guanidine cation [C(NH2)3]+ was trapped;for polymer 2, a mixedligand system was observed;N5 – and ATz coordinate separately with Na+and form two independent but interweaved nets. In this way, coordination polymer has been successfully utilized to modify specific properties of energetic materials through crystallization. Benefiting from the coordination and weak interactions, the decomposition temperatures of both polymers increase from 111°C(1D structure [Na(H2 O)(N5)]?2 H2 O) to 118.4 and 126.5°C respectively. Moreover, no crystallized H2 O was generated in products to afford the anhydrous compounds of pentazole salts with high heats of formation( >800 kJ mol–1). Compared to traditional energetic materials, the advantage in heats of formation is still obvious for the cyclo-N5– based CPs, which highlights cyclo-N5– as a promising energetic precursor for high energy density materials(HEDMs).
文摘Deposition of clean and defect-free atomically thin two-dimensional crystalline flakes on surfaces by mechanical exfoliation of layered bulk materials has proven to be a powerful technique, but it requires a fast, reliable and non-destructive way to identify the atomically thin flakes among a crowd of thick flakes. In this work, we provide general guidelines to identify ultrathin flakes of TaSe2 by means of optical microscopy and Raman spectroscopy. Additionally, we determine the optimal substrates to facilitate the optical identification of atomically thin TaSe2 crystals. Experimental realization and isolation of ultrathin layers of TaSe2 enables future studies on the role of the dimensionality in interesting phenomena such as superconductivity and charge density waves.
