一种最优化期望时延的容迟网络副本分发协议

多副本路由协议能有效降低容迟网络消息交付时延。目前的工作仅将节点间的当前质量作为分发依据,忽视了容迟网络固有的大延迟交付特性。提出了分发跳数约束的最优化消息期望时延的路由协议ODCD(optimal expected delay copy dis-semination),能在整个分发时间维度内选择最佳中继节点以优化期望时延。ODCD利用最佳停止规则进行建模,设计了综合性的动态分发尺度和相应的分发规则,并提出了一个用于计算该尺度的反向递归算法。在真实接触数据集上的仿真表明,相比同类算法,ODCD以少量发送成功率上的损失获得了在消息端到端时延和路由代价上的明显优势。

Multiscale Simulation Starting at the Molecular Level for Adsorption Process Development

This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.

Stochastic fluctuations of permittivity coupling regulate seizure dynamics in partial epilepsy

Partial epilepsy is characterized by recurrent seizures that arise from a localized pathological brain region. During the onset of partial epilepsy, the seizure evolution commonly exhibits typical timescale separation phenomenon. This timescale separation behavior can be mimicked by a paradigmatic model termed as Epileptor, which consists of coupled fast-slow neural populations via a permittivity variable. By incorporating permittivity noise into the Epileptor model, we show here that stochastic fluctuations of permittivity coupling participate in the modulation of seizure dynamics in partial epilepsy. In particular, introducing a certain level of permittivity noise can make the model produce more comparable seizure-like events that capture the temporal variability in realistic partial seizures. Furthermore, we observe that with the help of permittivity noise our stochastic Epileptor model can trigger the seizure dynamics even when it operates in the theoretical nonepileptogenic regime. These findings establish a deep mechanistic understanding on how stochastic fluctuations of permittivity coupling shape the seizure dynamics in partial epilepsy,and provide insightful biological implications.

Untangling the interactions among the Sustainable Development Goals in China

Understanding the interactions(synergies and trade-offs)among the Sustainable Development Goals(SDGs)is crucial for enhancing policy coherence between different sectors.However,spatial differences in the SDG interactions and their temporal variations at the sub-national scale are still critical gaps that need to be urgently filled.Here,we assess the spatial and temporal variation of the SDG interactions in China based on the systematic classification framework of SDGs.The framework groups the seventeen SDGs into three categories,namely“Essential Needs”“Objectives”,and“Governance”.Spatially,we found that the SDGs in“Essential Needs”&“Objectives”and“Essential Needs”&“Governance”generally show trade-offs in the eastern provinces of China.Synergies among all three SDG categories are observed in some central and western China provinces,which implies that these regions conform to sustainable development patterns.In addition,temporally,the synergies of the three SDG categories have shown a weakening trend in the last decade,mainly due to the regional differences in the progress of SDG7(Affordable and Clean Energy).Overall,our results identify the necessity for provinces to enhance the synergies between SDG12(Responsible Production and Consumption)and other SDGs to tackle the trade-offs between the“Essential Needs”and“Objectives”.Meanwhile,promoting the progress of SDG7 will also contribute to balanced development across provinces.

Constraining fast radio burst progenitors with gravitational lensing

Fast Radio Bursts(FRBs)are new transient radio sources discovered recently.Because of the angular resolution restriction in radio surveys,no optical counter part has been identified yet so it is hard to determine the progenitor of FRBs.In this paper we propose to use radio lensing survey to constrain FRB progenitors.We show that,different types of progenitors lead to different probabilities for a FRB to be gravitationally lensed by dark matter halos in foreground galaxies,since different type progenitors result in different redshift distributions of FRBs.For example,the redshift distribution of FRBs arising from double stars shifts toward lower redshift than of the FRBs arising from single stars,because double stars and single stars have different evolution timescales.With detailed calculations,we predict that the FRB sample size for producing one lensing event varies significantly for different FRB progenitor models.We argue that this fact can be used to distinguish different FRB models and also discuss the practical possibility of using lensing observation in radio surveys to constrain FRB progenitors.