Numerical simulation is employed to investigate the initial state of avalanche in polydisperse particle systems.Nucleation and propagation processes are illustrated for pentadisperse and triadisperse particle systems,...Numerical simulation is employed to investigate the initial state of avalanche in polydisperse particle systems.Nucleation and propagation processes are illustrated for pentadisperse and triadisperse particle systems,respectively.In these processes,particles involved in the avalanche grow slowly in the early stage and explosively in the later stage,which is clearly different from the continuous and steady growth trend in the monodisperse system.By examining the avalanche propagation,the number growth of particles involved in the avalanche and the slope of the number growth,the initial state can be divided into three stages:T1(nucleation stage),T2(propagation stage),T3(overall avalanche stage).We focus on the characteristics of the avalanche in the T2 stage,and find that propagation distances increase almost linearly in both axial and radial directions in polydisperse systems.We also consider the distribution characteristics of the average coordination number and average velocity for the moving particles.The results support that the polydisperse particle systems are more stable in the T2 stage.展开更多
Silicon suboxide(SiO_(x),x≈1)is promising in serving as an anode material for lithium-ion batteries with high capacity,but it has a low initial Coulombic efficiency(ICE)due to the irreversible formation of lithium si...Silicon suboxide(SiO_(x),x≈1)is promising in serving as an anode material for lithium-ion batteries with high capacity,but it has a low initial Coulombic efficiency(ICE)due to the irreversible formation of lithium silicates during the first cycle.In this work,we modify SiO_(x) by solid-phase Mg doping reaction using low-cost Mg powder as a reducing agent.We show that Mg reduces SiO_(2) in SiO_(x) to Si and forms MgSiO_(3) or Mg_(2)SiO_(4).The MgSiO_(3) or Mg_(2)SiO_(4) are mainly distributed on the surface of SiO_(x),which suppresses the irreversible lithium-ion loss and enhances the ICE of SiO_(x).However,the formation of MgSiO_(3) or Mg_(2)SiO_(4) also sacrifices the capacity of SiO_(x).Therefore,by controlling the reaction process between Mg and SiO_(x),we can tune the phase composition,proportion,and morphology of the Mg-doped SiO_(x) and manipulate the performance.We obtain samples with a capacity of 1226 mAh g^(–1) and an ICE of 84.12%,which show significant improvement over carbon-coated SiO_(x) without Mg doping.By the synergistical modification of both Mg doping and prelithiation,the capacity of SiO_(x) is further increased to 1477 mAh g^(–1) with a minimal compromise in the ICE(83.77%).展开更多
Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial pertur...Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial perturbation method tends only to capture synoptic scale initial uncertainty rather than mesoscale uncertainty in global ensemble prediction. To address this issue, a multiscale SV initial perturbation method based on the China Meteorological Administration Global Ensemble Prediction System(CMA-GEPS) is proposed to quantify multiscale initial uncertainty. The multiscale SV initial perturbation approach entails calculating multiscale SVs at different resolutions with multiple linearized physical processes to capture fast-growing perturbations from mesoscale to synoptic scale in target areas and combining these SVs by using a Gaussian sampling method with amplitude coefficients to generate initial perturbations. Following that, the energy norm,energy spectrum, and structure of multiscale SVs and their impact on GEPS are analyzed based on a batch experiment in different seasons. The results show that the multiscale SV initial perturbations can possess more energy and capture more mesoscale uncertainties than the traditional single-SV method. Meanwhile, multiscale SV initial perturbations can reflect the strongest dynamical instability in target areas. Their performances in global ensemble prediction when compared to single-scale SVs are shown to(i) improve the relationship between the ensemble spread and the root-mean-square error and(ii) provide a better probability forecast skill for atmospheric circulation during the late forecast period and for short-to medium-range precipitation. This study provides scientific evidence and application foundations for the design and development of a multiscale SV initial perturbation method for the GEPS.展开更多
High frequency pulsating voltage injection method is a good candidate for detecting the initial rotor position of permanent magnet synchronous motor.However,traditional methods require a large number of filters,which ...High frequency pulsating voltage injection method is a good candidate for detecting the initial rotor position of permanent magnet synchronous motor.However,traditional methods require a large number of filters,which leads to the deterioration of system stability and dynamic performance.In order to solve these problems,a new signal demodulation method is proposed in this paper.The proposed new method can directly obtain the amplitude of high-frequency current,thus eliminating the use of filters,improving system stability and dynamic performance and saving the work of adjusting filter parameters.In addition,a new magnetic polarity detection method is proposed,which is robust to current measurement noise.Finally,experiments verify the effectiveness of the method.展开更多
Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)an...Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site.Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes.The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(SI)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes.Consequently,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method.Three modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation results.Also,the average MBE of net radiation was reduced by 7%,22%,and 21%.展开更多
BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychologi...BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities.展开更多
The 20,000-ton combined train running has greatly promoted China’s heavy-haul railway transportation capability. The application of controllable train-tail devices could improve the braking wave of the train and brak...The 20,000-ton combined train running has greatly promoted China’s heavy-haul railway transportation capability. The application of controllable train-tail devices could improve the braking wave of the train and braking synchronism, and alleviate longitudinal impulse.However, the characteristics of the controllable train-tail device such as exhaust area, exhaust duration and exhaust action time are not uniform in practice, and their effects on the longitudinal impulse of the train are not apparent,which is worth studying. In this work, according to the formation of the Datong-Qinhuangdao Railway, the train air brake and longitudinal dynamics simulation system(TABLDSS) is applied to establish a 20,000-ton combined train model with the controllable train-tail device, and the braking characteristics and the longitudinal impulse of the train are calculated synchronously with changing the air exhaust time, exhaust area, and action lag time under initial braking. The results show that the maximum coupler force of the combined train will decrease with the extension of the continuous exhaust time, while the total exhaust time of the controllable train-tail device remains unchanged;the maximum coupler force of the combined train reduces by32.5% with the exhaust area increasing from 70% to 140%;when the lag time between the controllable train-tail device and the master locomotive is more than 1.5 s, the maximum coupler force of the train increases along with the time difference enlargement.展开更多
AIM:To determine initial medication adherence in newly diagnosed glaucoma patients treated with anti-glaucoma drugs.METHODS:This retrospective and observational study included all patients diagnosed with glaucoma in t...AIM:To determine initial medication adherence in newly diagnosed glaucoma patients treated with anti-glaucoma drugs.METHODS:This retrospective and observational study included all patients diagnosed with glaucoma in the Primary Health Care units in Portugal during the years 2012 and 2013,which in consequence received a first prescription for anti-glaucoma drugs.Data was collected from electronic prescribing records of the primary care units and from pharmacy claims records.Initiation of glaucoma treatment and early discontinuation were measured,and the combination of(non)-initiation and early discontinuation accounted for initial medication(non)-adherence.RESULTS:A total of 3548 new glaucoma patients(40.1%male;59.9%female)were included.The 1133(31.9%)patients were initially classified as non-users,since there was no pharmacy claim found for their first prescription for glaucoma treatment.Additionally,277(11.5%)patients early discontinued their treatment,acquiring only their first prescription.Overall,the initial medication non-adherence rate was 39.7%since 1410 patients either didn’t initiate treatment or discontinued it early.CONCLUSION:This study,reveals a major opportunity to improve glaucoma treatment and its control,since a large proportion of patients fail to engage with their prescribed therapy,which implies that implementation of individual or group strategies that enable patients with glaucoma to correctly perform their treatment is still needed.展开更多
There are rich emergent phase behaviors in non-equilibrium active systems.Flocking and clustering are two representative dynamic phases.The relationship between both the phases is still unclear.Herein,we numerically i...There are rich emergent phase behaviors in non-equilibrium active systems.Flocking and clustering are two representative dynamic phases.The relationship between both the phases is still unclear.Herein,we numerically investigate the evolution of flocking and clustering in a system consisting of self-propelled particles with active reorientation.We consider the interplay between flocking and clustering phases with different initial configurations,and observe a domain in steady state order parameter phase diagrams sensitive to the choice of initial configurations.Specifically,by tuning the initial degree of polar ordering,either a more ordered flocking or a disordered clustering state can be observed in the steady state.These results enlighten us to manipulate emergent behaviors and collective motions of an active system,and are qualitatively different from the emergence of a new bi-stable regime observed in aligned active particles due to an explicit attraction[New J.Phys.14073033(2012)].展开更多
A global weak solution to the isentropic Navier-Stokes equation with initial data around a constant state in the L^(1)∩BV class was constructed in[1].In the current paper,we will continue to study the uniqueness and ...A global weak solution to the isentropic Navier-Stokes equation with initial data around a constant state in the L^(1)∩BV class was constructed in[1].In the current paper,we will continue to study the uniqueness and regularity of the constructed solution.The key ingredients are the Holder continuity estimates of the heat kernel in both spatial and time variables.With these finer estimates,we obtain higher order regularity of the constructed solution to Navier-Stokes equation,so that all of the derivatives in the equation of conservative form are in the strong sense.Moreover,this regularity also allows us to identify a function space such that the stability of the solutions can be established there,which eventually implies the uniqueness.展开更多
Initial Coulombic efficiency(ICE)has been widely adopted in battery research as a quantifiable indicator for the lifespan,energy density and rate performance of batteries.Hard carbon materials have been accepted as a ...Initial Coulombic efficiency(ICE)has been widely adopted in battery research as a quantifiable indicator for the lifespan,energy density and rate performance of batteries.Hard carbon materials have been accepted as a promising anode family for sodium-ion batteries(SIBs)owing to their outstanding performance.However,the booming application of hard carbon anodes has been significantly slowed by the low ICE,leading to a reduced energy density at the cell level.This offers a challenge to develop high ICE hard carbon anodes to meet the applications of high-performance SIBs.Here,we discuss the definition and factors of ICE and describe several typical strategies to improve the ICE of hard carbon anodes.The strategies for boosting the ICE of such anodes are also systematically categorized into several aspects including structure design,surface engineering,electrolyte optimization and pre-sodiation.The key challenges and perspectives in the development of high ICE hard carbon anodes are also outlined.展开更多
As prior researchers have suggested,a firm’s success in an international market depends on how well its strategy fits the nonmarket environment,such as formal institutions.This paper examines the determinants of form...As prior researchers have suggested,a firm’s success in an international market depends on how well its strategy fits the nonmarket environment,such as formal institutions.This paper examines the determinants of formal institutions around new areas of economic activities.Specifically,we propose a framework for understanding how the quality of formal institutions in promoting entrepreneurship drives the focus of such institutions concerning initial coin offering(ICO),which is emerging as a popular fundraising method.The paper uses inductive analysis to examine how nonmarket factors—such as a jurisdiction’s tax haven nature,regulators’perceptions of ICOs as threats to national or political interests,and trade and industry associations—might moderate the relationship between the quality of institutions and the focus of such institutions regarding ICOs.One of this study’s key findings is that an economy’s quality of entrepreneurship-related institutions,perceived threats to national/political interests,and tax haven nature lead to different policy orientations.Consequently,regulators assign different importance when promoting crypto-entrepreneurship and dealing with associated risks.Regulators focusing mainly on promoting crypto-ventures have taken measures to enrich the blockchain ecosystem and provided tax and non-tax incentives to attract such ventures.Regulators focusing mainly on dealing with crypto-venture risks rely on a regulatory sandbox and close regulatory monitoring of such ventures.展开更多
A statistical analysis of the initial vortexes leading to tropical cyclone(TC)formation in the western North Pacific(WNP)is conducted with the ECMWF ERA5 reanalysis data from 1999 to 2018.It is found that TCs in the W...A statistical analysis of the initial vortexes leading to tropical cyclone(TC)formation in the western North Pacific(WNP)is conducted with the ECMWF ERA5 reanalysis data from 1999 to 2018.It is found that TCs in the WNP basically originate from three kinds of vortexes,i.e.,a mid-level vortex(MV),a low-level vortex(LV),and a relatively deep vortex with notable vorticity in both the lower and middle troposphere(DV).Among them,LV and DV account for 47.9%and 24.2%of tropical cyclogenesis events,respectively,while only 27.9%of TCs develop from the MV,which is much lower than that which occurs in the North Atlantic and eastern Pacific.Such a difference might be ascribed to the active monsoon systems in the WNP all year round.Due to the nearly upright structure of mid-level convergence in the early pre-genesis stage,TC genesis efficiency is the highest in DV.Compared with MV,LV generally takes a shorter time to intensify to a TC because of the higher humidity and the stronger low-level cyclonic circulation,which is related to air-sea interaction and boundary-layer convergence.Further examination of the relationship between tropical cyclogenesis and large-scale flow patterns indicate that the TC genesis events associated with LV are primarily related to the monsoon shear line,monsoon confluence region,and monsoon gyre,while those associated with MV are frequently connected with easterly waves and wave energy dispersion of preexisting TC.Compared with other flow patterns,tropical cyclones usually form and intensify faster in the monsoon confluence region.展开更多
Hard carbon(HC)is a promising anode material for sodium ion batteries(SIBs),whereas inferior initial coulombic efficiency(ICE)severely limits its practical application.In the present work,we propose an in situ electro...Hard carbon(HC)is a promising anode material for sodium ion batteries(SIBs),whereas inferior initial coulombic efficiency(ICE)severely limits its practical application.In the present work,we propose an in situ electrochemical presodiation approach to improve ICE by mixing sodium biphenyl(Na-Bp)dimethoxyethane(DME)solution with DME-based ether electrolyte.A solid electrolyte interface(SEI)could be formed beforehand on the HC electrode and Na^(+)was absorbed to nanopores and graphene stacks,compensating for the sodium loss and preventing electrolyte decomposition during the initial charge and discharge cycle.By this way,the ICE of half-cells was increased to nearly 100%and that of full-cells from 45%to 96%with energy density from 132.9 to 230.5 W h kg^(-1).Our work provides an efficient and facile method for improving ICE,which can potentially promote the practical application of HCbased materials.展开更多
We consider the fourth-order nonlinear Schr?dinger equation(4NLS)(i?t+εΔ+Δ2)u=c1um+c2(?u)um-1+c3(?u)2um-2,and establish the conditional almost sure global well-posedness for random initial data in Hs(Rd)for s∈(sc-...We consider the fourth-order nonlinear Schr?dinger equation(4NLS)(i?t+εΔ+Δ2)u=c1um+c2(?u)um-1+c3(?u)2um-2,and establish the conditional almost sure global well-posedness for random initial data in Hs(Rd)for s∈(sc-1/2,sc],when d≥3 and m≥5,where sc:=d/2-2/(m-1)is the scaling critical regularity of 4NLS with the second order derivative nonlinearities.Our proof relies on the nonlinear estimates in a new M-norm and the stability theory in the probabilistic setting.Similar supercritical global well-posedness results also hold for d=2,m≥4 and d≥3,3≤m<5.展开更多
Initial labor market conditions affect how individuals build their human capital and look for jobs and thus can have long-term effects on their income levels,work performance,and career development.Based on data from ...Initial labor market conditions affect how individuals build their human capital and look for jobs and thus can have long-term effects on their income levels,work performance,and career development.Based on data from the Urban Household Survey(UHS)of urban households in China from 1986 to 2009,we perform an empirical test of how initial labor market conditions affect the employability of individuals.Our research shows that people’s future incomes suffer if they start out in an adverse job market.Each percentage point of increase in the unemployment rate at an individual’s entry into the labor market is associated with a two-percentage-point drop in his or her average annual income.Even after looking at different parts of the job market and sample groups,this conclusion still holds.In the context of global economic instability,our findings may assist government policymakers in addressing adverse labor market conditions.展开更多
Minimizing transportation time and getting optimal solutions are always considered as important factors while solving transportation problem. This paper shows a new approach for finding initial basic solution for tran...Minimizing transportation time and getting optimal solutions are always considered as important factors while solving transportation problem. This paper shows a new approach for finding initial basic solution for transportation problem which reduces cost of transportation more than any transportation method such as LCM, northwest, Vogel’s approximation and so on. This method has been illustrated by taking an example;afterwards, it compares basic initial feasible solution with other methods IBF and optimal dictate solutions such as MODI and Steppingstone method.展开更多
This study investigates the modulation of initial wind field structure on the relationship between the size and intensity of a simulated vortex.A series of idealized experiments are conducted by varying the radius of ...This study investigates the modulation of initial wind field structure on the relationship between the size and intensity of a simulated vortex.A series of idealized experiments are conducted by varying the radius of maximum wind(RMW)and shape parameter of the initial vortices.The size–intensity relationship is quantified by the linear regression coefficient of the azimuthally-averaged gale-force wind radius against the maximum wind during the development stage,reflecting the degree of size expansion at the same intensity increment.The regression coefficient increases with increased RMW and decreased,with the RMW being the primary constraint.The effect of lowering on the elevation of the regression coefficient gradually stands out when the initial RMW is large.Enlarging the RMW leads to a secondary circulation with a horizontally elongated structure,which retards the intensification while promoting size expansion,thus substantially enhancing size expansion as the vortex intensifies.Broadening the wind field outside the RMW by reducing results in abounding convection in the outer region,which promotes size expansion.Based on the axisymmetric tangential wind tendency and Sawyer–Eliassen equations,when the RMW is large,the active convection in the outer region can weaken the radial inflow induced by the eyewall heating in the inner region,thus retarding the intensification by reducing the radial imports of vorticity near the RMW.展开更多
Uemura [1] discovered the mapping formula for Type 1 Vague events and presented an alternative problem as an example of its application. Since it is well known that the alternative problem leads to sequential Bayesian...Uemura [1] discovered the mapping formula for Type 1 Vague events and presented an alternative problem as an example of its application. Since it is well known that the alternative problem leads to sequential Bayesian inference, the flow of subsequent research was to make the mapping formula multidimensional, to introduce the concept of time, and to derive a Markov (decision) process. Furthermore, we formulated stochastic differential equations to derive them [2]. This paper refers to type 2 vague events based on a second-order mapping equation. This quadratic mapping formula gives a certain rotation named as possibility principal factor rotation by transforming a non-mapping function by a relation between two mapping functions. In addition, the derivation of the Type 2 Complex Markov process and the initial and stopping conditions in this rotation are mentioned. .展开更多
We report a case of a 12-year-old female with closed and open comedo without inflammatory lesions at the first visit. She had been treated with topical adapalene once daily, and closed and open comedo subsided without...We report a case of a 12-year-old female with closed and open comedo without inflammatory lesions at the first visit. She had been treated with topical adapalene once daily, and closed and open comedo subsided without inflammatory lesions one month after the treatment without any side effects induced by adapalen. The recurrence of comedo had not been observed afterwards. In the Japanese Dermatological Association (JDA) guidelines for the treatment of acne vulgaris, comedonal phase has not been stated. Then we propose the tentative new terminology of a comedonal phase and emphasize its importance in the early initial treatment for comedo to prevent the development of the acute inflammatory phase such as red papules and pustules and formation of acne scars.展开更多
基金Project supported by the Qingdao National Laboratory for Marine Science and Technology(Grant No.2015ASKJ01)the National Natural Science Foundation of China(Grant Nos.11972212,12072200,and 12002213).
文摘Numerical simulation is employed to investigate the initial state of avalanche in polydisperse particle systems.Nucleation and propagation processes are illustrated for pentadisperse and triadisperse particle systems,respectively.In these processes,particles involved in the avalanche grow slowly in the early stage and explosively in the later stage,which is clearly different from the continuous and steady growth trend in the monodisperse system.By examining the avalanche propagation,the number growth of particles involved in the avalanche and the slope of the number growth,the initial state can be divided into three stages:T1(nucleation stage),T2(propagation stage),T3(overall avalanche stage).We focus on the characteristics of the avalanche in the T2 stage,and find that propagation distances increase almost linearly in both axial and radial directions in polydisperse systems.We also consider the distribution characteristics of the average coordination number and average velocity for the moving particles.The results support that the polydisperse particle systems are more stable in the T2 stage.
基金supported by the National Natural Science Foundation(52232009)the National Natural Science Foundation for Distinguished Young Scholar(52125404)+1 种基金the National Youth Talent Support Program,“131”First Level Innovative Talents Training Project in Tianjinthe Tianjin Natural Science Foundation for Distinguished Young Scholar(18JCJQJC46500).
文摘Silicon suboxide(SiO_(x),x≈1)is promising in serving as an anode material for lithium-ion batteries with high capacity,but it has a low initial Coulombic efficiency(ICE)due to the irreversible formation of lithium silicates during the first cycle.In this work,we modify SiO_(x) by solid-phase Mg doping reaction using low-cost Mg powder as a reducing agent.We show that Mg reduces SiO_(2) in SiO_(x) to Si and forms MgSiO_(3) or Mg_(2)SiO_(4).The MgSiO_(3) or Mg_(2)SiO_(4) are mainly distributed on the surface of SiO_(x),which suppresses the irreversible lithium-ion loss and enhances the ICE of SiO_(x).However,the formation of MgSiO_(3) or Mg_(2)SiO_(4) also sacrifices the capacity of SiO_(x).Therefore,by controlling the reaction process between Mg and SiO_(x),we can tune the phase composition,proportion,and morphology of the Mg-doped SiO_(x) and manipulate the performance.We obtain samples with a capacity of 1226 mAh g^(–1) and an ICE of 84.12%,which show significant improvement over carbon-coated SiO_(x) without Mg doping.By the synergistical modification of both Mg doping and prelithiation,the capacity of SiO_(x) is further increased to 1477 mAh g^(–1) with a minimal compromise in the ICE(83.77%).
基金supported by the Joint Funds of the Chinese National Natural Science Foundation (NSFC)(Grant No.U2242213)the National Key Research and Development (R&D)Program of the Ministry of Science and Technology of China(Grant No. 2021YFC3000902)the National Science Foundation for Young Scholars (Grant No. 42205166)。
文摘Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial perturbation method tends only to capture synoptic scale initial uncertainty rather than mesoscale uncertainty in global ensemble prediction. To address this issue, a multiscale SV initial perturbation method based on the China Meteorological Administration Global Ensemble Prediction System(CMA-GEPS) is proposed to quantify multiscale initial uncertainty. The multiscale SV initial perturbation approach entails calculating multiscale SVs at different resolutions with multiple linearized physical processes to capture fast-growing perturbations from mesoscale to synoptic scale in target areas and combining these SVs by using a Gaussian sampling method with amplitude coefficients to generate initial perturbations. Following that, the energy norm,energy spectrum, and structure of multiscale SVs and their impact on GEPS are analyzed based on a batch experiment in different seasons. The results show that the multiscale SV initial perturbations can possess more energy and capture more mesoscale uncertainties than the traditional single-SV method. Meanwhile, multiscale SV initial perturbations can reflect the strongest dynamical instability in target areas. Their performances in global ensemble prediction when compared to single-scale SVs are shown to(i) improve the relationship between the ensemble spread and the root-mean-square error and(ii) provide a better probability forecast skill for atmospheric circulation during the late forecast period and for short-to medium-range precipitation. This study provides scientific evidence and application foundations for the design and development of a multiscale SV initial perturbation method for the GEPS.
基金supported by the National Natural Science Foundation of China under Grant 51991384Anhui Provincial Major Science and Technology Project under Grant 202203c08020010。
文摘High frequency pulsating voltage injection method is a good candidate for detecting the initial rotor position of permanent magnet synchronous motor.However,traditional methods require a large number of filters,which leads to the deterioration of system stability and dynamic performance.In order to solve these problems,a new signal demodulation method is proposed in this paper.The proposed new method can directly obtain the amplitude of high-frequency current,thus eliminating the use of filters,improving system stability and dynamic performance and saving the work of adjusting filter parameters.In addition,a new magnetic polarity detection method is proposed,which is robust to current measurement noise.Finally,experiments verify the effectiveness of the method.
基金the National Natural Science Foundation of China(Grant No.U20A2081)West Light Foundation of the Chinese Academy of Sciences(Grant No.xbzg-zdsys-202102)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Project(Grant No.2019QZKK0105).
文摘Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site.Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes.The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(SI)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes.Consequently,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method.Three modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation results.Also,the average MBE of net radiation was reduced by 7%,22%,and 21%.
文摘BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities.
基金China National Railway Group Co.,Ltd(N2020J037).
文摘The 20,000-ton combined train running has greatly promoted China’s heavy-haul railway transportation capability. The application of controllable train-tail devices could improve the braking wave of the train and braking synchronism, and alleviate longitudinal impulse.However, the characteristics of the controllable train-tail device such as exhaust area, exhaust duration and exhaust action time are not uniform in practice, and their effects on the longitudinal impulse of the train are not apparent,which is worth studying. In this work, according to the formation of the Datong-Qinhuangdao Railway, the train air brake and longitudinal dynamics simulation system(TABLDSS) is applied to establish a 20,000-ton combined train model with the controllable train-tail device, and the braking characteristics and the longitudinal impulse of the train are calculated synchronously with changing the air exhaust time, exhaust area, and action lag time under initial braking. The results show that the maximum coupler force of the combined train will decrease with the extension of the continuous exhaust time, while the total exhaust time of the controllable train-tail device remains unchanged;the maximum coupler force of the combined train reduces by32.5% with the exhaust area increasing from 70% to 140%;when the lag time between the controllable train-tail device and the master locomotive is more than 1.5 s, the maximum coupler force of the train increases along with the time difference enlargement.
文摘AIM:To determine initial medication adherence in newly diagnosed glaucoma patients treated with anti-glaucoma drugs.METHODS:This retrospective and observational study included all patients diagnosed with glaucoma in the Primary Health Care units in Portugal during the years 2012 and 2013,which in consequence received a first prescription for anti-glaucoma drugs.Data was collected from electronic prescribing records of the primary care units and from pharmacy claims records.Initiation of glaucoma treatment and early discontinuation were measured,and the combination of(non)-initiation and early discontinuation accounted for initial medication(non)-adherence.RESULTS:A total of 3548 new glaucoma patients(40.1%male;59.9%female)were included.The 1133(31.9%)patients were initially classified as non-users,since there was no pharmacy claim found for their first prescription for glaucoma treatment.Additionally,277(11.5%)patients early discontinued their treatment,acquiring only their first prescription.Overall,the initial medication non-adherence rate was 39.7%since 1410 patients either didn’t initiate treatment or discontinued it early.CONCLUSION:This study,reveals a major opportunity to improve glaucoma treatment and its control,since a large proportion of patients fail to engage with their prescribed therapy,which implies that implementation of individual or group strategies that enable patients with glaucoma to correctly perform their treatment is still needed.
基金support from the Beijing Computational Science Research Centersupported by the National Natural Science Foundation of China(Grant Nos.U2230402,11975050,11735005,and 11904320)。
文摘There are rich emergent phase behaviors in non-equilibrium active systems.Flocking and clustering are two representative dynamic phases.The relationship between both the phases is still unclear.Herein,we numerically investigate the evolution of flocking and clustering in a system consisting of self-propelled particles with active reorientation.We consider the interplay between flocking and clustering phases with different initial configurations,and observe a domain in steady state order parameter phase diagrams sensitive to the choice of initial configurations.Specifically,by tuning the initial degree of polar ordering,either a more ordered flocking or a disordered clustering state can be observed in the steady state.These results enlighten us to manipulate emergent behaviors and collective motions of an active system,and are qualitatively different from the emergence of a new bi-stable regime observed in aligned active particles due to an explicit attraction[New J.Phys.14073033(2012)].
基金partially the National Key R&D Program of China(2022YFA1007300)the NSFC(11901386,12031013)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA25010403)the NSFC(11801194,11971188)the Hubei Key Laboratory of Engineering Modeling and Scientific Computing。
文摘A global weak solution to the isentropic Navier-Stokes equation with initial data around a constant state in the L^(1)∩BV class was constructed in[1].In the current paper,we will continue to study the uniqueness and regularity of the constructed solution.The key ingredients are the Holder continuity estimates of the heat kernel in both spatial and time variables.With these finer estimates,we obtain higher order regularity of the constructed solution to Navier-Stokes equation,so that all of the derivatives in the equation of conservative form are in the strong sense.Moreover,this regularity also allows us to identify a function space such that the stability of the solutions can be established there,which eventually implies the uniqueness.
基金supported by the National Key R&D Program of China(2018YFE0201701 and 2018YFA0209401)the National Natural Science Foundation of China(Grant nos.22088101,U21A20329,21733003 and 21975050)+1 种基金the Science and Technology Commission of Shanghai Municipality(19JC1410700)Program of Shanghai Academic Research Leader(21XD1420800)。
文摘Initial Coulombic efficiency(ICE)has been widely adopted in battery research as a quantifiable indicator for the lifespan,energy density and rate performance of batteries.Hard carbon materials have been accepted as a promising anode family for sodium-ion batteries(SIBs)owing to their outstanding performance.However,the booming application of hard carbon anodes has been significantly slowed by the low ICE,leading to a reduced energy density at the cell level.This offers a challenge to develop high ICE hard carbon anodes to meet the applications of high-performance SIBs.Here,we discuss the definition and factors of ICE and describe several typical strategies to improve the ICE of hard carbon anodes.The strategies for boosting the ICE of such anodes are also systematically categorized into several aspects including structure design,surface engineering,electrolyte optimization and pre-sodiation.The key challenges and perspectives in the development of high ICE hard carbon anodes are also outlined.
文摘As prior researchers have suggested,a firm’s success in an international market depends on how well its strategy fits the nonmarket environment,such as formal institutions.This paper examines the determinants of formal institutions around new areas of economic activities.Specifically,we propose a framework for understanding how the quality of formal institutions in promoting entrepreneurship drives the focus of such institutions concerning initial coin offering(ICO),which is emerging as a popular fundraising method.The paper uses inductive analysis to examine how nonmarket factors—such as a jurisdiction’s tax haven nature,regulators’perceptions of ICOs as threats to national or political interests,and trade and industry associations—might moderate the relationship between the quality of institutions and the focus of such institutions regarding ICOs.One of this study’s key findings is that an economy’s quality of entrepreneurship-related institutions,perceived threats to national/political interests,and tax haven nature lead to different policy orientations.Consequently,regulators assign different importance when promoting crypto-entrepreneurship and dealing with associated risks.Regulators focusing mainly on promoting crypto-ventures have taken measures to enrich the blockchain ecosystem and provided tax and non-tax incentives to attract such ventures.Regulators focusing mainly on dealing with crypto-venture risks rely on a regulatory sandbox and close regulatory monitoring of such ventures.
基金supported in part by the Nature Science Foundation of China under Grant Nos.41875046,42175004National Key Research and Development Program of China under Grant No.2017YFC1501601Shanghai“Science and Technology Innovation Action Plan”Yangtze River Delta Science and Technology Innovation Community Field Project Grant 21002410200。
文摘A statistical analysis of the initial vortexes leading to tropical cyclone(TC)formation in the western North Pacific(WNP)is conducted with the ECMWF ERA5 reanalysis data from 1999 to 2018.It is found that TCs in the WNP basically originate from three kinds of vortexes,i.e.,a mid-level vortex(MV),a low-level vortex(LV),and a relatively deep vortex with notable vorticity in both the lower and middle troposphere(DV).Among them,LV and DV account for 47.9%and 24.2%of tropical cyclogenesis events,respectively,while only 27.9%of TCs develop from the MV,which is much lower than that which occurs in the North Atlantic and eastern Pacific.Such a difference might be ascribed to the active monsoon systems in the WNP all year round.Due to the nearly upright structure of mid-level convergence in the early pre-genesis stage,TC genesis efficiency is the highest in DV.Compared with MV,LV generally takes a shorter time to intensify to a TC because of the higher humidity and the stronger low-level cyclonic circulation,which is related to air-sea interaction and boundary-layer convergence.Further examination of the relationship between tropical cyclogenesis and large-scale flow patterns indicate that the TC genesis events associated with LV are primarily related to the monsoon shear line,monsoon confluence region,and monsoon gyre,while those associated with MV are frequently connected with easterly waves and wave energy dispersion of preexisting TC.Compared with other flow patterns,tropical cyclones usually form and intensify faster in the monsoon confluence region.
基金supported by the National Natural Science Foundation of China,China(51932011,52072411,52104285)the Natural Science Foundation of Hunan Province,China(2021JJ20060)+1 种基金the Science and Technology Innovation Program of Hunan Province,China(2021RC3001)the Fundamental Research Funds for the Central Universities,China(202044011)。
文摘Hard carbon(HC)is a promising anode material for sodium ion batteries(SIBs),whereas inferior initial coulombic efficiency(ICE)severely limits its practical application.In the present work,we propose an in situ electrochemical presodiation approach to improve ICE by mixing sodium biphenyl(Na-Bp)dimethoxyethane(DME)solution with DME-based ether electrolyte.A solid electrolyte interface(SEI)could be formed beforehand on the HC electrode and Na^(+)was absorbed to nanopores and graphene stacks,compensating for the sodium loss and preventing electrolyte decomposition during the initial charge and discharge cycle.By this way,the ICE of half-cells was increased to nearly 100%and that of full-cells from 45%to 96%with energy density from 132.9 to 230.5 W h kg^(-1).Our work provides an efficient and facile method for improving ICE,which can potentially promote the practical application of HCbased materials.
基金supported by the NationalNatural Science Foundation of China(12001236)the Natural Science Foundation of Guangdong Province(2020A1515110494)。
文摘We consider the fourth-order nonlinear Schr?dinger equation(4NLS)(i?t+εΔ+Δ2)u=c1um+c2(?u)um-1+c3(?u)2um-2,and establish the conditional almost sure global well-posedness for random initial data in Hs(Rd)for s∈(sc-1/2,sc],when d≥3 and m≥5,where sc:=d/2-2/(m-1)is the scaling critical regularity of 4NLS with the second order derivative nonlinearities.Our proof relies on the nonlinear estimates in a new M-norm and the stability theory in the probabilistic setting.Similar supercritical global well-posedness results also hold for d=2,m≥4 and d≥3,3≤m<5.
基金supported by the General Project of the National Natural Science Fund of China(NSFC)“China’s Labor Market Matching Efficiency and Economic Effects”(Grant No.71973015)the Major Project of the National Social Science Fund of China(NSSFC)“Study on Enhancing Employment Priority for Stable Job Growth”(Grant No.21ZDA098).
文摘Initial labor market conditions affect how individuals build their human capital and look for jobs and thus can have long-term effects on their income levels,work performance,and career development.Based on data from the Urban Household Survey(UHS)of urban households in China from 1986 to 2009,we perform an empirical test of how initial labor market conditions affect the employability of individuals.Our research shows that people’s future incomes suffer if they start out in an adverse job market.Each percentage point of increase in the unemployment rate at an individual’s entry into the labor market is associated with a two-percentage-point drop in his or her average annual income.Even after looking at different parts of the job market and sample groups,this conclusion still holds.In the context of global economic instability,our findings may assist government policymakers in addressing adverse labor market conditions.
文摘Minimizing transportation time and getting optimal solutions are always considered as important factors while solving transportation problem. This paper shows a new approach for finding initial basic solution for transportation problem which reduces cost of transportation more than any transportation method such as LCM, northwest, Vogel’s approximation and so on. This method has been illustrated by taking an example;afterwards, it compares basic initial feasible solution with other methods IBF and optimal dictate solutions such as MODI and Steppingstone method.
基金This study is supported by the National Natural Science Foundation of China(Grant Nos.42175073 and 41975071).
文摘This study investigates the modulation of initial wind field structure on the relationship between the size and intensity of a simulated vortex.A series of idealized experiments are conducted by varying the radius of maximum wind(RMW)and shape parameter of the initial vortices.The size–intensity relationship is quantified by the linear regression coefficient of the azimuthally-averaged gale-force wind radius against the maximum wind during the development stage,reflecting the degree of size expansion at the same intensity increment.The regression coefficient increases with increased RMW and decreased,with the RMW being the primary constraint.The effect of lowering on the elevation of the regression coefficient gradually stands out when the initial RMW is large.Enlarging the RMW leads to a secondary circulation with a horizontally elongated structure,which retards the intensification while promoting size expansion,thus substantially enhancing size expansion as the vortex intensifies.Broadening the wind field outside the RMW by reducing results in abounding convection in the outer region,which promotes size expansion.Based on the axisymmetric tangential wind tendency and Sawyer–Eliassen equations,when the RMW is large,the active convection in the outer region can weaken the radial inflow induced by the eyewall heating in the inner region,thus retarding the intensification by reducing the radial imports of vorticity near the RMW.
文摘Uemura [1] discovered the mapping formula for Type 1 Vague events and presented an alternative problem as an example of its application. Since it is well known that the alternative problem leads to sequential Bayesian inference, the flow of subsequent research was to make the mapping formula multidimensional, to introduce the concept of time, and to derive a Markov (decision) process. Furthermore, we formulated stochastic differential equations to derive them [2]. This paper refers to type 2 vague events based on a second-order mapping equation. This quadratic mapping formula gives a certain rotation named as possibility principal factor rotation by transforming a non-mapping function by a relation between two mapping functions. In addition, the derivation of the Type 2 Complex Markov process and the initial and stopping conditions in this rotation are mentioned. .
文摘We report a case of a 12-year-old female with closed and open comedo without inflammatory lesions at the first visit. She had been treated with topical adapalene once daily, and closed and open comedo subsided without inflammatory lesions one month after the treatment without any side effects induced by adapalen. The recurrence of comedo had not been observed afterwards. In the Japanese Dermatological Association (JDA) guidelines for the treatment of acne vulgaris, comedonal phase has not been stated. Then we propose the tentative new terminology of a comedonal phase and emphasize its importance in the early initial treatment for comedo to prevent the development of the acute inflammatory phase such as red papules and pustules and formation of acne scars.
