Co-pyrolysis characteristics of typical components of waste plastics in a falling film pyrolysis reactor

Waste plastics mainly come from MSW and usually exist in the form of mixed plastics. During the co-pyrolysis process of mixed plastics, various plastic components have different physicochemical properties and reaction mechanisms. Considering the high viscosity and low thermal conductivity of molten plastics, a falling film pyrolysis reactor was selected to explore the rapid co-pyrolysis process of typical plastic components(PP, PE and PS).The oil and gas yields and the compositions of pyrolysis products of the three components under different ratios at pyrolysis temperatures were analyzed to explore the co-pyrolysis characteristics of PP, PE, and PS. The study is of great significance to the recycling of waste plastics.

Molten waste plastic pyrolysis in a vertical falling film reactor and the influence of temperature on the pyrolysis products

Molten plastics are characterised with high viscosity and low thermal conductivity. Applying falling film pyrolysis reactor to deal with waste plastics can not only improve heat transfer efficiency, but also solve the flow problem.In this work, the pyrolysis process of molten polypropylene(PP) in a vertical falling film reactor is experimentally studied, and the influence of heating temperature on pyrolysis products is discussed. It has been found that with the temperature increases from 550 ℃ to 625 ℃, the yield of pyrolysis oil decreases from 74.4 wt%(± 2.2 wt%) to53.5 wt%(±1.3 wt%). The major compositions of the pyrolysis oil are C_9, C_(12) and C_(18), and β-scission reactions are predominant. The content of the light fraction C_6-C_(12) of pyrolysis oil is 69.7 wt%. Compared with other pyrolysis reactors, the yield of oil from vertical falling film pyrolysis reactor is slightly higher than that from tubular reactor,equal to that from rotary kiln reactor, and slightly lower than that in medium fluidised-bed reactor.

Heat transfer characteristics of molten plastics in a vertical falling film reactor

The heat transfer efficiency during the pyrolysis process is a key factor to be considered in the design of pyrolysis reactors. In this study, the average apparent heat transfer characteristics of molten plastic pyrolysis in a vertical falling film reactor were explored by experiments and numerical simulation and the apparent heat transfer coefficients were determined. In addition, the temperature distribution and the thickness of the liquid film in the reactor were predicted and the influences of pyrolysis temperatures on the average apparent heat transfer coefficients were discussed.

Inflammation and cancer: paradoxical roles in tumorigenesis and implications in immunotherapies

Chronic inflammation caused by persistent infections and metabolic disorders is thought to contribute to the increased cancer risk and the accelerated cancer progression.Oppositely,acute inflammation induced by bacteria-based vaccines or that is occurring after cancer selectively inhibits cancer progression and metastasis.However,the interaction between inflammation and cancer may be more complex than the current explanations for the relationship between chronic and acute inflammation and cancer.In this review,we described the impact of inflammation on cancer on the basis of three perspectives,including inflammation with different durations(chronic and acute inflammation),different scopes(systemic and local inflammation)and different occurrence sequences(inflammation occurring after and before cancer).In addition,we also introduced bacteria/virus-based cancer immunotherapies.We perceive that inflammation may be a double-edged sword with cancer-promoting and cancer-suppressing functions in certain cases.We expect to further improve the understanding of the relationship between inflammation and cancer and provide a theoretical basis for further research on their complex interaction.

具有电子调制平面异质结的金属有机骨架纳米片用于高电流密度全解水

设计基于界面工程的氧/氢析出反应(OER/HER)双功能电催化剂对在高电流密度下同时实现低过电位和稳定的水分解操作至关重要.本文中,我们报告了一种硼化策略以巧妙地定制固定在泡沫铁(IF)上的金属有机框架(MOF).硼原子诱导了Fe-MOF纳米片的结构重构,包括粗糙表面、氧空位以及结晶Fe-MOF和非晶Fe–B之间的面内异质结.面内异质结调节铁位点的d带中心以降低OER/HER能垒.优化的Fe–B/FeMOF/IF在10 m A cm^(-2)下驱动OER和全解水,分别仅需1.44和1.53 V.水分解系统在500 m A cm^(-2)下工作100小时以后的结构变化和性能衰减可忽略不计.该工作为异质结构界面的工程提供了启示,并促进了先进电催化剂的合理设计.

不对称配位操纵电子再分布实现高电流密度下电催化水氧化

作为目前最有前景的绿氢生产方式,电解水技术被研究者广泛关注.其中,电催化析氧反应(oxygen evolution reaction,OER)作为电解水的半反应,由于其缓慢的四电子转移步骤而成为电解水器件的能量瓶颈.高效的OER催化电极设计是解决该问题的有效方式.本文分析了OER催化剂中氧原子介导的电子重排与活性位点配位不对称性之间的构效关系.通过自发氧化还原反应,将镍离子引入到泡沫镍(NF)表面的FeWO_(4)中,以此破坏FeWO_(4)晶格中FeO_(6)八面体的对称性,并基于此调节Fe位点的电子结构.结构调控促进了钨酸盐适度重构成为具有高OER活性的羟基氧化物.在碱性环境中,具有不对称配位Fe位点的Fe_(0.53)Ni_(0.47)WO_(4)/NF自支撑电极在10 mA cm^(-2)的电流密度下,可获得170 mV的超低过电势,并在1000 mA cm^(-2)的高电流密度下可维持稳定500 h.这种新型OER催化电极为高活性电催化系统的设计提供了新的见解.

Amorphous porous sulfides nanosheets with hydrophilic/aerophobic surface for high-current-density water splitting

The rational construction of electrocatalysts with desired features is significant but challenging for superior water splitting at high current density. Herein, amorphous Co Ni S nanosheets are synthesized on nickel foam(NF) through a facile structure evolution strategy and present advanced performance at high current densities in water splitting. The high catalytic activity can be attributed to the sufficient active sites exposed by the flexible amorphous configuration. Moreover, the hydrophilicity and aerophobicity of a-CoNiS/NF promote surface wettability of the self-supporting electrode and avoid the aggregation of bubbles, which expedites the diffusion of electrolyte and facilitates the mass transfer. As a result, the optimized electrode demonstrates low overpotentials of 289 and 434 m V at 500 m A/cm^(2) under alkaline conditions for hydrogen evolution reaction(HER) and oxygen evolution reaction(OER), respectively. Impressively, an electrolytic water splitting cell assembled by bifunctional a-Co Ni S/NF operates with a low cell voltage of 1.46 V@10 mA/cm^(2) and reaches 1.79 V at 500 mA/cm^(2). The strategy sheds light on a competitive platform for the reasonable design of non-precious-metal electrocatalysts under high current density.

Marmots do not consistently use their left eye to respond to an approaching threat but those that did fled sooner

In many vertebrates,the brain's right hemisphere which is connected to the left visual field specializes in the processing of information about threats while the left hemisphere which is connected to the right visual field specializes in the processing of information about conspecifics.This is referred to as hemispheric lateralization.But individuals that are too predictable in their response to predators could have reduced survival and we may expect selection for somewhat unpredictable responses.We studied hemispheric lateralization in yellow-bellied marmots Marmota flaviventer,a social rodent that falls prey to a variety of terrestrial and aerial predators.We first asked if they have lateralized responses to a predatory threat.We then asked if the eye that they used to assess risk influenced their perceptions of risk.We recorded the direction marmots were initially looking and then walked toward them until they fled.We recorded the distance that they responded to our experimental approach by looking,the eye with which they looked at us,and the distance at which they fled (i.e.,flight initiation distance;FID).We found that marmots had no eye preference with which they looked at an approaching threat.Furthermore,the population was not comprised of individuals that responded in consistent ways.However,we found that marmots that looked at the approaching person with their left eye had larger FIDs suggesting that risk assessment was influenced by the eye used to monitor the threat.These findings are consistent with selection to make prey less predictable for their predators,despite underlying lateralization.

Male attacks on infants and infant death during male takeovers in wild white-headed langurs(Trachypithecus leucocephalus)

Infanticide was first observed in langurs nearly 50 years ago,and this rare phenomenon has been inferred to have either an evolutionarily adaptive function or to be a pathological and non-functional behavior.In this study,we report 5 male takeover events in one-male groups of white-headed langurs in the Nongguan Karst Hills,Guangxi,China from 1998 to 2006.We recorded 13 attacks on 9 infants by extra-group males or new resident males.During the male takeovers,all of the infants younger than 6 months(with an average age of 3.6 months[N=11])in the groups disappeared.The infant death rate during the 4.2 months after takeover by a new male was significantly higher than the infant death rate calculated for most of the year.Older infants that were still nursing(with an average age of 14.1 months[N=7])were often attacked and seriously wounded by the extra-group males or new resident males,but all of them survived.The interbirth intervals of females whose infants were assumed to be killed by males were significantly reduced relative to those of females in groups with stable male tenure(mean=10 months vs 25 months).Our data suggest that males kill unrelated and unweaned infants during the takeover period to decrease the time until the infants’mothers resume fertility.Thus,infanticide would support sexual selection theory in white-headed langurs.The data also show that infanticidal behavior was directed toward the infants,especially those who were still nursing.Female dispersal may function as a counter-strategy to avoid infanticide.

In situ construction of thiol-silver interface for selectively electrocatalytic CO_(2)reduction

Electrochemical CO_(2)reduction(ECR)is one of the most effective methods to obtain carbonaceous chemicals and reduce greenhouse gases passingly under the ambient condition.However,efficient electrocatalysts featured with high selectivity and stability are still lacking.A novel molecule-mediated Ag electrocatalyst with capped thiols is rationally designed for high-performance ECR.The thiol-capped and carbon-supported Ag nanostructures(Ag-TC)are formed by in situ electrochemical reduction from three-dimentional(3D)Ag-thiol metal-organic compound with cysteine as the anchor agent and carbon source.Ag-TC exhibits high selectivity and stability for CO_(2)conversion to CO(86.7%),which is more catalytically active than that of common Ag nanoparticles.The function of thiols for ECR is proved by replacing cysteine with alanine without thiol group.Meanwhile,alternatively replacing and removing the surface molecules on the Ag foil further demonstrate the effct of thiols.This work enlightens the promise of in situ construction method for molecule capped metal electrocatalyst towards selective and stable ECR.

Erratum to:In situ construction of thiol-silver interface for selectively electrocatalytic CO_(2)reduction

Erratum to Nano Research 2022,15(4):3283−3289 https://doi.org/10.1007/s12274-021-3978-7 One funding number in the Acknowledgements section was unfortunately mistakenly used.This error did not affect any of the conclusions from the published paper.