Recent Advances in Organic-inorganic Hybrid Photoresists

Photoresists are radiation-sensitive materials used for forming patterns to build up IC devices.To date,most photoresists have been based on organic polymers,which have been dominating the semiconductor industries over the past few decades.It is obvious that extreme ultraviolet(EUV)lithography has become the next-generation lithography technology.The development of comprehensive performance EUV resist is one of the most critical issues.However,organic polymeric photoresists are difficult to meet the harsh requirements of EUV lithography.Pure inorganic photoresists such as metal salts,hydrogen silsesquioxane(HSQ)are expected for EUV lithography due to their high resistance and high resolution.But the low sensitivity makes them not suitable for high volume manufacturing(HVM).Organic-inorganic hybrid photoresists,containing both organic and inorganic components,are regarded as one of the most promising EUV resists.They combine both merits of organic and inorganic materials and have significant advantages in machinability,etching resistance,EUV absorption,and chemical/thermal stability.Organic-inorganic hybrid photoresists are considered as ideal materials for realizing industrialgrade patterns below 10 nm.This review mainly focuses on the development of organic-inorganic hybrid photoresists over the past decade.

The potential of 3D printing in facilitating carbon neutrality

At present,dramatically reduction of fossil fuel usage is regarded as a major initiative to achieve the carbon neutrality goal.Nevertheless,current energy policies are unlikely to achieve the climate goal without sacrificing economic development and people’s livelihood because fossil fuels are currently the dominant energy source.As an environment-friendly manufacturing technology,three-dimensional printing(3DP)is flourishing and is considered beneficial to energy structure adjustment and industrial upgrading.Despite this,its potential to contribute to global carbon neutrality has not attracted enough attention.Herein,we explore the application of 3DP and its potential facilitating carbon neutrality from crucial sectors and applications including manufacturing,construction energy,livestock,and carbon capture and storage(CCS)technologies.The additive manufacturing and decentralized manufacturing characteristics of 3DP allow reducing greenhouse gas(GHG)emissions in manufacturing and construction sectors by optimized and lightweight designs,reduced material and energy consumption,and shortened transport processes.In addition,3DP enables the precise manufacturing of customized complex structures and the expansion of functional materials,which makes 3DP an innovative alternative to the development of novel energy-related devices,cultured meat production technology,and CCS technologies.Despite this,the majority of applications of 3DP are still in an early stage and need further exploration.We call for further research to precisely evaluate the GHG emission reduction potential of 3DP and to make it better involved and deployed to better achieve carbon neutrality.

Multi-Agent Modeling and Simulation in the AI Age

With the rapid development of artificial intelligence(AI)technology and its successful application in various fields,modeling and simulation technology,especially multi-agent modeling and simulation(MAMS),of complex systems has rapidly advanced.In this study,we first describe the concept,technical advantages,research steps,and research status of MAMS.Then we review the development status of the hybrid modeling and simulation combining multi-agent and system dynamics,the modeling and simulation of multi-agent reinforcement learning,and the modeling and simulation of large-scale multi-agent.Lastly,we introduce existing MAMS platforms and their comparative studies.This work summarizes the current research situation of MAMS,thus helping scholars understand the systematic technology development of MAMS in the AI era.It also paves the way for further research on MAMS technology.

Control Design and Implementation of a Spiral Spring Energy Storage System Connected to a Grid via PMSG

For an innovative spiral spring energy storage system,the permanent magnet synchronous generator(PMSG)is utilized as the energy conversion device due to its simple structure,low weight and high torque.During power generation,the output torque and moment of inertia of the spiral spring are changing continuously and simultaneously and the parameters of the PMSG show uncertainties.Furthermore,the DC link voltage of the converter should be stable and the power injected into the grid needs to be controlled.First,the change features of the external power source and the uncertainties of the generator’s internal parameters are expressed as the comprehensive disturbances,which are introduced into the dynamic model of the PMSG and also modify the dynamic model.Then,the high gain observers are utilized to estimate the comprehensive disturbances,and an improved robust backstepping control scheme integrating L2 gain and high gain observers is proposed.Secondly,the gridside inverter controller for the DC voltage loop and reactive power loop is designed based on the backstepping theory.Finally,hardware implementation is fulfilled to verify the presented algorithm.The results show that high gain observers are able to accurately estimate the external and internal interferences;the proposed control scheme can effectively suppress the external and internal interferences and guarantees output current,operating speed of the PMSG and output reactive power to correctly track respective references,and effectively stabilize the DC link voltage.

Linkages of flow regime and micro-topography:prediction for non-native mangrove invasion under sea-level rise

Flow regime is a key driver of invasive aquatic organisms,and the invasiveness of mangrove species may be simultaneously attributed to plant traits and flowing hydrological conditions at the estuary scale.We focused on hydrological and topographic conditions for a non-native mangrove species,Sonneratia apetala,in Zhangjiang Estuary of Fujian,China.A hydrological model and a micro-topographic model were used to predict its dispersal and early establishment,and field surveys and simulated experiments were integrated to estimate its future dispersal patterns.The mesohaline mudflat with a salinity of 8~10 PSU at the mangrove seaward edge was the most likely colonization area for S.apetala under current conditions.The south-western region of the estuary with native mangroves was the most likely area for its colonization according to the unstructured-grid finite-volume community ocean model(FVCOM)in September,when the largest tidal currents within a year and the maximum fruit maturity period occur.Approximately 42%of the mudflats throughout the whole estuary may be available for seedling establishment under the future sea-level rise RCP 4.5 scenarios compared with 44%for current establishment;however,the RCP 8.5 scenarios would significantly decrease seedling establishment by 2100 due to serious tidal inundation according to the micro-topographical model.

The shift in the abundance of two Stipa species in response to land use change is associated with their divergent reproductive strategies

Aims The divergent changes of plant species under land use changes are key mechanisms underlying vegetation succession.Stipa grandis steppe and Stipa krylovii steppe are two plant commu-nities widely distributed on the Mongolian Plateau.They have been speculated to be able to succeed into each other under different land use types and intensities based on the observa-tions on their presence and abundance at the sites with dif-ferent land use history.However,no direct evidence,neither the underlying mechanisms,have been reported for this specu-lation.Here,we verified this speculation and explored the underlying mechanisms in the typical steppe region of Inner Mongolia.Methods We investigated the abundance and reproductive behavior of S.kry-lovii and S.grandis under different land use types and intensities.We used 18 grassland paddocks to run a 6-year experiment with 6 management treatments(T0-unused,T1-grazing monthly in plant growing season,T2,T4,T6-grazing in different months in plant growing season,and T8-mowing)replicated three times.We measured the relative density and cover of S.krylovii and S.grandis using line sampling method and examined their number and bio-mass of vegetative and reproductive tillers using quadrat method in each paddock after treatments for 4 and 6 years.We also de-termined these plant attributes in 14 pairs of heavily versus lightly used grassland plots in a wide area(150 km×200 km)of the typical steppe region.Important Findings 1.Grazing largely and mowing moderately decreased the density ratio and coverage ratio of S.grandis to S.krylovii in grasslands(P<0.05),and the differences in these ratios between grazed and unused grasslands increased with time.2.Grazing,but not mowing,significantly enhanced the relative density(N_(rep)=reproductive tiller number/total tiller number)of,and biomass allocation(B_(rep)=reproductive tiller biomass/total bio-mass)to,reproductive tillers of S.krylovii(P<0.05),but not S.gran-dis.This grazing enhancement to sexual reproduction of S.krylovii,and additionally inhibition to N_(rep) of S.grandis(P<0.05),were found across the 14 pairs of heavily versus lightly used plots.3.Seasonal pattern of grazing affected sexual reproduction of S.kry-lovii.The N_(rep) and B_(rep) was higher under grazing in July and September(T4)than in July and August(T6)or in May and July(T2)(P<0.05),suggesting a relatively positive effect of grazing on sexual reproduction in July(tasseling phenophase)than in May or August.Our results provide direct evidence to the reciprocal change of S.grandis and S.krylovii in steppe communities under different management and indicate that gazing or mowing enhancement of sexual reproduction of S.krylovii relative to S.grandis is one of the mechanisms for the change.

Control strategies and their effects on the COVID-19 pandemic in 2020 in representative countries

COVID-19 is the most severe pandemic globally since the 1918 influenza pandemic.Effectively responding to this once-in-a-century global pandemic is a worldwide challenge that the international community needs to jointly face and solve.This study reviews and discusses the key measures taken by major countries in 2020 to fight against COVID-19,such as lockdowns,social distancing,wearing masks,hand hygiene,using Fangcang shelter hospitals,large-scale nucleic acid testing,close-contacts tracking,and pandemic information monitoring,as well as their prevention and control effects.We hope it can help improve the efficiency and effectiveness of pandemic prevention and control in future.