Achieving stable K-storage performance of carbon sphere-confined Sb via electrolyte regulation

Potassium-ion batteries(PIBs)have been considered as one of the most promising alternatives to lithiumion batteries(LIBs)in view of their competitive energy density with significantly reduced product cost.Moreover,alloy-type materials are expected as a high-performance anode of PIBs thanks to their intrinsic chemical stability as well as high theoretical specific capacity.Unfortunately,the serious incompatibility between alloy-type active materials and electrolytes,especially for the formation of unstable solidelectrolyte interfacial(SEI)films,often leads to insufficient cycle life.Herein,the formation mechanism of SEI films in the K-storage systems based on carbon sphere confined Sb anode(Sb@CS)were investigated in commercially available electrolytes.Physical characterizations and theoretical calculation revealed that the solvents in the dilute electrolyte of 0.8 M KPF_(6)/EC+DEC were excessively decomposed on the interface to generate unstable SEI and thus result in inferior K-storage stability.On the contrary,a salt-concentrated electrolyte(3 M KFSI/DME)can generate inorganic-dominated stable SEI due to the preferential decomposition of anions.As a result,the prepared Sb@CS in the matched 3 M KFSI/DME electrolyte delivered a high reversible capacity of 467.8 m A h g^(-1)after 100 cycles at 100 m A g^(-1),with a slow capacity decay of 0.19%per cycle from the 10th to the 100th cycle.These findings are of great significance for revealing the interfacial reaction between electrodes and electrolytes as well as improving the stability of Sb-based anode materials for PIBs.

A proof system of the CaIT calculus

The Internet of Things(IoT)can realize the interconnection of people,machines,and things anytime,anywhere.Most of the existing research mainly focuses on the practical applications of IoT,and there is a lack of research on modeling and reasoning about IoT systems from the perspective of formal methods.Thus,the Calculus of the Internet of Things(CaIT)has been proposed to specify and analyze IoT systems before the actual implementation,which can effectively improve development efficiency,and enhance system quality and reliability.To verify the correctness of IoT systems described by CaIT,this paper presents a proof system for CaIT,in which specifications and verifications are based on the extended Hoare Logic with time.Furthermore,we explore the cooperation between isolated proofs to validate the postconditions of the communication actions occurring in these proofs,with a particular focus on broadcast communication.We also demonstrate the soundness of our proof system.A simple“smart home”is given to illustrate the availability of our proof system.

Hybrid speciation via inheritance of alternate alleles of parental isolating genes

It is increasingly realized that homoploid hybrid speciation(HHS),which involves no change in chromosome number,is an important mechanism of speciation.HHS will likely increase in frequency as ecological and geographical barriers between species are continuing to be disrupted by human activities.HHS requires the establishment of reproductive isolation between a hybrid and its parents,but the underlying genes and genetic mechanisms remain largely unknown.In this study,we reveal by integrated approaches that reproductive isolation originates in one homoploid hybrid plant species through the inheritance of altemate alleles at genes that determine parental premating isolation.The parent species of this hybrid species are reproductively isolated by differences in flowering time and survivorship on soils containing high concentrations of iron.We found that the hybrid species inherits alleles of parental isolating major genes related to flowering time from one parent and alleles of major genes related to iron tolerance from the other parent.In this way,it became reproductively isolated from one parent by the difference in flowering time and from the other by habitat adaptation(iron tolerance).These findings and further modeling results suggest that HHS may occur relatively easily via the inheritance of alternate parental premating isolating genes and barriers.

Application of Program Generation Technology in Solving Heat and Flow Problems

Based on a new DIY concept for software development, an automatic program-generating technology attached on a software system called as Finite Element Program Generator （FEPG） provides a platform of developing programs, through which a scientific researcher can submit his special physico-mathematical problem to the system in a more direct and convenient way for solution. For solving flow and heat problems by using finite element method, the stabilization technologies and fraction-step methods are adopted to overcome the numerical difficul- ties caused mainly due to the dominated convection. A couple of benchmark problems are given in this paper as examples to illustrate the usage and the superiority of the automatic program generation technique, including the flow in a lid-driven cavity, the starting flow in a circular pipe, the natural convection in a square cavity, and the flow past a circular cylinder, etc. They are also shown as the verification of the algorithms.