Inverse design and realization of an optical cavity-based displacement transducer with arbitrary responses

Optical cavity has long been critical for a variety of applications ranging from precise measurement to spectral analysis.A number of theories and methods have been successful in describing the optical response of a stratified optical cavity,while the inverse problem,especially the inverse design of a displacement sensitive cavity,remains a significant challenge due to the cost of computation and comprehensive performance requirements.This paper reports a novel inverse design methodology combining the characteristic matrix method,mixed-discrete variables optimization algorithm,and Monte Carlo method-based tolerance analysis.The material characteristics are indexed to enable the mixed-discrete variables optimization,which yields considerable speed and efficiency improvements.This method allows arbitrary response adjustment with technical feasibility and gives a glimpse into the analytical characterization of the optical response.Two entirely different light-displacement responses,including an asymmetric sawtooth-like response and a highly symmetric response,are dug out and experimentally achieved,which fully confirms the validity of the method.The compact Fabry-Perot cavities have a good balance between performance and feasibility,making them promising candidates for displacement transducers.More importantly,the proposed inverse design paves the way for a universal design of optical cavities,or even nanophotonic devices.

Unpredictability of Digital Twin for Connected Vehicles

Digital twin is an essential enabling technology for 6G connected vehicles.Through highfidelity mobility simulation,digital twin is expected to make accurate prediction about the vehicle trajectory,and then support intelligent applications such as safety monitoring and self-driving for connected vehicles.However,it is observed that even if a digital twin model is perfectly derived,it might still fail to predict the trajectory due to tiny measurement noise or delay in the initial vehicle locations.This paper aims at investigating the sources of unpredictability of digital twin.Take the car-following behaviors in connected vehicles for case study.The theoretical analysis and experimental results indicate that the predictability of digital twin naturally depends on its system complexity.Once a system enters a complex pattern,its longterm states are unpredictable.Furthermore,our study discloses that the complexity is determined,on the one hand,by the intrinsic factors of the target physical system such as the driver’s response sensitivity and delay,and on the other hand,by the crucial parameters of the digital twin system such as the sampling interval and twining latency.

聚丙烯腈纳米纤维膜连续预氧化碳化过程中的结构性能演变

对静电纺丝制备的聚丙烯腈(PAN)纳米纤维膜进行连续预氧化碳化处理,借助差示扫描量热仪、红外光谱、扫描电镜、元素分析、拉曼光谱、体密度、力学性能等表征和测试方法,综合分析了纳米纤维膜在预氧化碳化过程中的结构性能演变。研究结果表明,相较于微米级的PAN聚合体,纳米纤维具有更低的环化活化能,当氧化纳米纤维的氧含量为8.3%时,得到的碳纳米纤维膜综合性能较佳,其密度、碳收率和拉伸强度分别为1.799 g/cm^(3),59.8%和29.6 MPa。

Contemporary trends on expenditure of hospital care on total cancer and its subtypes in China during 2008-2017

Objective:To describe the contemporary trends in total,inpatient,and outpatient expenditure on major subtypes of cancer in different classifications of hospitals in China's Mainland.Methods:Home page of Inpatient Medical Records(HIMRs)and Hospital Annual Reports(HARs)were used to estimate hospital care expenditure on cancer.Inpatient payments and their share of cancer were calculated with the top-down method.Kriging spatial interpolation methods were used at the county level and summed at the province level.Outpatient expenditure was estimated with inpatient expenditure and the ratios of outpatient to inpatient payments in specialized cancer hospitals,stratified by province.Total expenditure on cancer was the sum of both payments.Log-linear regression was applied to estimate annual percentage change(APC)of expenditure.Results:Total expenses for cancer of Chinese residents reached up to 304.84 billion Chinese Yuan(CNY)in2017,accounting for 5.8%of the total health expenses(THE).After adjusting for consumer price index(CPI),medical expenses for cancer have increased from 63.30 billion CNY in 2008 to 249.56 billion CNY in 2017[APC:15.2%,95%confidence interval(95%CI):13.4%-17.0%].The APC was slightly higher than THE around 2013,while was lower after 2013.During 2008-2017,the ratio of inpatient to outpatient costs for cancer decreased from4.3:1 to 3.8:1.The inpatient payments for cancer mainly happened in grade 3 general hospitals,East China,and among lung,colorectal,and stomach cancer;while the fastest increase was found in West China,and among thyroid,prostate,and colorectal cancer.Conclusions:During 2008-2017,the rapid growth trend of medical expenses for cancer has been effectively controlled with the continuous deepening of medical reform and improvements of residents’health care.More attention should be paid to potential increases of medical costs caused by technological progress and demand release.Socialized and multi-channel insurance financing modes should be explored in the future.

Review of micromachined optical accelerometers:from mg to sub-μg

Micro-Opto-Electro-Mechanical Systems(MOEMS)accelerometer is a new type of accelerometer which combines the merits of optical measurement and Micro-Electro-Mechanical Systems(MEMS)to enable high precision,small volume and anti-electromagnetic disturbance measurement of acceleration.In recent years,with the in-depth research and development of MOEMS accelerometers,the community is flourishing with the possible applications in seismic monitoring,inertial navigation,aerospace and other industrial and military fields.There have been a variety of schemes of MOEMS accelerometers,whereas the performances differ greatly due to different measurement principles and corresponding application requirements.This paper aims to address the pressing issue of the current lack of systematic review of MOEMS accelerometers.According to the optical measurement principle,we divide the MOEMS accelerometers into three categories:the geometric optics based,the wave optics based,and the new optomechanical accelerometers.Regarding the most widely studied category,the wave optics based accelerometers are further divided into four sub-categories,which is based on grating interferometric cavity,Fiber Bragg Grating(FBG),Fabry-Perot cavity,and photonic crystal,respectively.Following a brief introduction to the measurement principles,the typical performances,advantages and disadvantages as well as the potential application scenarios of all kinds of MOEMS accelerometers are discussed on the basis of typical demonstrations.This paper also presents the status and development tendency of MOEMS accelerometers to meet the ever-increasing demand for high-precision acceleration measurement.

Review on piezoelectric actuators:materials,classifications,applications,and recent trends

Piezoelectric actuators are a class of actuators that precisely transfer input electric energy into displacement,force,or movement outputs efficiently via inverse piezoelectric effect-based electromechanical coupling.Various types of piezoelectric actuators have sprung up and gained widespread use in various applications in terms of compelling attributes,such as high precision,flexibility of stoke,immunity to electromagnetic interference,and structural scalability.This paper systematically reviews the piezoelectric materials,operating principles,representative schemes,characteristics,and potential applications of each mainstream type of piezoelectric actuator.Herein,we intend to provide a more scientific and nuanced perspective to classify piezoelectric actuators into direct and indirect categories with several subcategories.In addition,this review outlines the pros and cons and the future development trends for all kinds of piezoelectric actuators by exploring the relations and mechanisms behind them.The rich content and detailed comparison can help build an in-depth and holistic understanding of piezoelectric actuators and pave the way for future research and the selection of practical applications.

Topological superconductor candidates PdBi_(2)Te_(4) and PdBi_(2)Te_(5) from a generic ab initio strategy

Superconducting topological metals(SCTMs)have recently emerged as a promising platform of topological superconductivity(TSC)and Majorana zero modes for quantum computation.Despite their importance in both fundamental research and applications,SCTMs are very rare in nature.Here,we propose a strategy to design SCTMs by intercalating the superconducting units into the topological insulators.A program that characterizes the superconducting BdG Chern number of 2D BdG Hamiltonian from ab initio calculations is also developed.Following this strategy,PdBi_(2)Te_(5) and PdBi_(2)Te_(4) are found to be experimentally synthesizable and ideal SCTMs.Chiral TSC could be realized in such SCTMs by incorporating topological surface states with Zeeman effect,which can be realized by an external magnetic field or in proximity to ferromagnetic insulator.Our strategy provides a new method for identifying the SCTMs and TSC candidates,and the program makes it possible to design and modulate the TSC candidates from ab initio calculations.

Ascorbate peroxidase 1 confers resistance to southern corn leaf blight in maize

Southern corn leaf blight (SCLB), caused by Bipolarismaydis, is one of the most devastatingdiseases affecting maize production. However,only one SLCB resistance gene, conferring partialresistance, is currently known, underscoring theimportance of isolating new SCLB resistancerelatedgenes. Here, we performed a comparativeproteomic analysis and identified 258 proteinsshowing differential abundance during the maizeresponse to B. maydis. These proteins included anascorbate peroxidase (Zea mays ascorbate peroxidase1 (ZmAPX1)) encoded by a gene locatedwithin the mapping interval of a previously identifiedquantitative trait locus associated with SCLBresistance. ZmAPX1 overexpression resulted inlower H_(2)O_(2) accumulation and enhanced resistanceagainst B. maydis. Jasmonic acid (JA)contents and transcript levels for JA biosynthesisand responsive genes increased in ZmAPX1-overexpressing plants infected with B. maydis,whereas Zmapx1 mutants showed the oppositeeffects. We further determined that low levels of H_(2)O_(2) are accompanied by an accumulation of JAthat enhances SCLB resistance. These resultsdemonstrate that ZmAPX1 positively regulatesSCLB resistance by decreasing H_(2)O_(2) accumulationand activating the JA-mediated defensesignaling pathway. This study identified ZmAPX1as a potentially useful gene for increasing SCLBresistance. Furthermore, the generated datamay be relevant for clarifying the functions ofplant APXs.

The Pumilio RNA-binding protein APUM24 regulates seed maturation by fine-tuning the BPM-WRI1 module in Arabidopsis

Pumilio RNAbindingproteinsparticipateinmes-senger RNA(mRNA)degradation and t ranslational repression,but their roles in plant development are largely unclear.Here,we show that Arabidopsis PUMILIO PROTEIN24(APUM24),an atypical Pumiliohomology domaincontaining protein,plays an im-portant part in regulating seed maturation,a major stage of plant development.APUM24 is strongly expressed in maturing seeds.Reducing APUM24 expression resulted in abnormal seed maturation,wrinkled seeds,and lower seed oil contents,and APUM24 knockdown resulted in lower levels of WRINKLED 1(WRI1),a key transcription factor con-trolling seed oil accumulation,and lower expression of WRI1 target genes.APUM24 reduces the mRNA stability of BTB/POZMATH(BPM)family genes,thus decreasing BPM protein levels.BPM is responsible for the 26S proteasomemediated degradation of WRI1 and has important functions in plant growth and development.The 3′untranslated regions of BPM family genes contain putative Pumilio response elements(PREs),which are bound by APUM24.Re-duced BPM or increased WRI1 expression rescued the decient seed maturation of apum242 knock-down mutants,and APUM24 overexpression re-sulted in increased seed size and weight.Therefore,APUM24 is crucial to seed maturation through its action as a positive regulatornetuning the BPMWRI1 module,making APUM24 apromising target for breeding strategies to increase crop yields.

Design of platinum single-atom doped metal nanoclusters as efficient oxygen reduction electrocatalysts by coupling electronic descriptor

Inspired by the single-atom catalysts(SACs)concept,we rationally design a series of Pt single atom catalysts embedded in different transition metal nanoclusters through first-principles calculations.In these so-called“crown-jewel”(CJ)structures,Pt atoms(jewels)occupy the vertex sites of the metal nanocluster(crown)surface.We investigated the thermal stability and oxygen reduction reaction(ORR)catalytic activity of these catalysts.The results reveal that CJ-structured PtCu nanoclusters are stable and possess a comparable or even better ORR activity compared to Pt catalyst,making it a promising candidate for low-cost ORR catalysts.The effect of cluster size on the adsorption strength of ORR intermediates and catalytic property has also been studied.Furthermore,the overall ORR catalytic activity trend of these SACs is explained based on analysis of their electronic properties.A descriptorΨwas established to provide further insight into the correlation between the electronic structure and catalytic activity,which provides a design strategy for new ORR catalysts.More importantly,we reveal that this electronic descriptor can be extended to predict other CJ-structured nanoclusters.

MXenes@Te as a composite material for high-performance aluminum batteries

The emerging two-dimensional(2D)materials,MXenes,play an important role in various fields of energy storage and exhibit excellent electrochemical performance.Herein,we prepared few-layered MXenes(F-Ti_(3)C_(2)T_(x))and loaded Te on the surface of F-Ti_(3)C_(2)T_(x) by using a simple hightemperature evaporation method.In addition,the electrochemical performance of the aluminum battery with F-Ti_(3)C_(2)T_(x) as support material was studied.The initial charge/discharge specific capacities are 987/1096mAh g^(-1)at 0.2Ag^(-1).An obvious discharge voltage plateau of about 1.3V appears at various current densities.The specific capacity is about 258mAh g^(-1)with MXenes@Te as the active material in the aluminum battery,which benefits from the excellent electronic conductivity of the MXenes and their 2D layered structure.Density functional theory calculations were carried out to explore the mechanism.Ti_(3)C_(2)O_(2)@Te is more inclined to adsorb[AlCl_(4)]^(-) than Ti_(3)C_(2)O_(2).Furthermore,the valence change behavior of element Te was studied by using thermodynamic calculation(FactSage 7.1).X-ray photoelectron spectroscopy results show that when the battery is fully charged to 2.4V element Te and Ti ions(Ti^(3+),Ti^(2+))are oxidized to Te^(4+)and Ti^(4+).In contrast to the charging process,the high-valence Te^(4+)and Ti^(4+)are reduced again during discharging.Element Te is reduced to lower-valence Te^(2-)when the discharge voltage is lower than 0.6 V,and a higher charge voltage(2.56 V)is required for Te to be oxidized to Te^(6+).

Cancer epidemiological database linkage study of China:Design,methods,and quality evaluation

To the Editor:Data linkage is a method of identifying and combining information derived from various sources that actually belongs to the same individual or event.[1]In recent years,data linkage has become an increasingly common practice in many countries.The socioeconomic and health benefits of data linkage in the healthcare field can be clearly demonstrated.From the perspective of scientific research,the combination of multidimensional health-related data at the individual level(e.g.,risk factor data,clinical diagnosis and treatment data,community management and follow-up data,disease surveillance data,birth,and vital statistics)and public records(e.g.,environmental monitoring data,motor vehicle crash data,criminal data)can create scientific inspiration in multiple disciplines and spur innovation.From the perspective of health management.