Ether-/Ester-/Fluorine-Rich Binding Emulsion Formula for Lithium-Ion Batteries

Practical application of a Si anode in a high-energy-density battery cannot be achieved due to the huge volume expansion of these anodes.Researchers have focused on binders of the anode to restrict volume expansion in order to address this issue,as the hydrogen bonds and mechanical properties of binders can be used to enhance adhesion and accommodate the volume changes of a Si anode.Herein,we comprehensively consider binders’hydrogen bonds,mechanical properties,stability,and compatibility with the electrolyte solution,and design an ether-/ester-/fluorine-rich composite polymer,named P(TFEMAco-IBVE).The proposed binder formula possesses outstanding stability,adhesion,and mechanical strength;moreover,it can accommodate the dramatic volume changes of a Si electrode and exhibits excellent electrochemical performance,achieving a high areal capacity of about 5.4 mA·h·cm^(-2).This novel polymer design may be applied to other electrode materials in the next generation of lithium-ion batteries.

Polymeric nanocomposites for electrocaloric refrigeration

Electrocaloric refrigeration represents an alternative solid-state cooling technology that has the potential to reach the ultimate goal of achieving zero-global-warming potential,highly efficient refrigeration,and heat pumps.To date,both polymeric and inorganic oxides have demonstrated giant electrocaloric effect as well as respective cooling devices.Although both polymeric and inorganic oxides have been identified as promising cooling methods that are distinguishable from the traditional ones,they still pose many challenges to more practical applications.From an electrocaloric material point of view,electrocaloric nanocomposites may provide a solution to combine the beneficial effects of both organic and inorganic electrocaloric materials.This article reviews the recent advancements in polymer-based electrocaloric composites and the state-of-the-art cooling devices operating these nanocomposites.From a device point of view,it discusses the existing challenges and potential opportunities of electrocaloric nanocomposites.

Why is it difficult to accurately predict the COVID-19 epidemic?

Since the COVID-19 outbreak in Wuhan City in December of 2019,numerous model predictions on the COVID-19 epidemics in Wuhan and other parts of China have been reported.These model predictions have shown a wide range of variations.In our study,we demonstrate that nonidentifiability in model calibrations using the confirmed-case data is the main reason for such wide variations.Using the Akaike Information Criterion(AIC)for model selection,we show that an SIR model performs much better than an SEIR model in representing the information contained in the confirmed-case data.This indicates that predictions using more complex models may not be more reliable compared to using a simpler model.We present our model predictions for the COVID-19 epidemic in Wuhan after the lockdown and quarantine of the city on January 23,2020.We also report our results of modeling the impacts of the strict quarantine measures undertaken in the city after February 7 on the time course of the epidemic,and modeling the potential of a second outbreak after the return-to-work in the city.

Photothermy-strengthened photocatalytic activity of polydopamine-modified metal-organic frameworks for rapid therapy of bacteria-infected wounds

Herein,a metal-organic framework(MOF)was modified using polydopamine(PDA)to develop the MOFPDA as a photoresponsive bacteria-killing agent under 660 nm light irradiation.The modification using PDA led to the production of not only more heat,but also much more~1O_(2).This is because the PDA could interact with the porphyrin ring of the MOF throughπ-πinteraction and the charge transfer between PDA and the MOFs decreases the ene rgy of the band of hybrid nanoparticles.In addition,greater levels of hyperthermia induced by PDA modification accelerated the charge trans fe r,which significantly strengthened the photocatalytic perfo rmance of MO F-PDA.Furthermore,after modification,the light abso rbance and water dispersibility of nanoparticles were both enhanced;both are important for the improvement of photocatalytic and photothermal properties.Consequently,MOF-PDA exhibited the highly effective antibacterial efficacy of 99.62%and 99.97%against Staphylococcus aureus and Escherichia coli,respectively,under 20 min 660 nm light irradiation.

Systemic delivery of microRNA for treatment of brain ischemia

Brain ischemia is the second leading cause of death and the third leading cause of disability in the world.Systemic delivery of microRNA,a class of molecules that regulate the expression of cellular proteins associated with angiogenesis,cell growth,proliferation and differentiation,holds great promise for the treatment of brain ischemia.However,their therapeutic efficacy has been hampered by poor delivery efficiency of microRNA.We report herein a platform technology based on microRNA nanocapsules,which enables their effective delivery to the disease sites in the brain.Exemplified by microRNA-21,intravenous injection of the nanocapsules into a rat model of cerebral ischemia could effectively ameliorate the infarct volume,neurological deficit and histopathological severity.

Mathematical modeling of the dynamics of COVID-19 variants of concern:Asymptotic and finite-time perspectives

The COVID-19 pandemic has seen multiple waves,in part due to the implementation and relaxation of social distancing measures by the public health authorities around the world,and also caused by the emergence of new variants of concern(VOCs)of the SARS-Cov-2 virus.As the COVID-19 pandemic is expected to transition into an endemic state,how to manage outbreaks caused by newly emerging VOCs has become one of the primary public health issues.Using mathematical modeling tools,we investigated the dynamics of VOCs,both in a general theoretical framework and based on observations from public health data of past COVID-19 waves,with the objective of understanding key factors that determine the dominance and coexistence of VOCs.Our results show that the transmissibility advantage of a new VOC is a main factor for it to become dominant.Additionally,our modeling study indicates that the initial number of people infected with the new VOC plays an important role in determining the size of the epidemic.Our results also support the evidence that public health measures targeting the newly emerging VOC taken in the early phase of its spread can limit the size of the epidemic caused by the new VOC(Wu et al.,2139Wu,Scarabel,Majeed,Bragazzi,&Orbinski,Wu et al.,2021).

政治心理与政治行为研究70年:议题、方法与展望

新中国成立70年来,中国政治学在政治心理与政治行为方面的研究取得了长足的进步。在学科发展与建设上,政治心理与行为研究走向多元化的发展,产生了丰富的研究成果。改革开放后,中国政治的发展、全球化都对整个研究领域产生了重大影响:在具体议题中,民主价值观、政治参与、社会资本、腐败感知、国际观等研究百花齐放;在研究方法上,各类社会调查不断推进和深入为各种研究提供了可靠数据,同时实验方法、大数据与机器学习方兴未艾。展望未来,中国政治发展、技术革命和全球化仍然会为政治心理与行为的研究提供源源不断的动力。