This note concerns the rapid uniform convergence of Cesàro weighted Birkhoff averages via irrational rotations on tori under certain conditions,involving arbitrary polynomial and exponential convergence rates.We ...This note concerns the rapid uniform convergence of Cesàro weighted Birkhoff averages via irrational rotations on tori under certain conditions,involving arbitrary polynomial and exponential convergence rates.We discuss both finite dimensional and infinite dimensional cases,and give Diophantine rotations as examples.These provide the universality of rapid convergence for Cesàro weighted type,which is quite different from Lp(p>1)convergence for the unweighted one.We also show a certain optimality about our convergence rate.Besides,we introduce a multimodal weighted approach to adapt to the data sparsity,which still preserves exponential convergence.展开更多
This study looks at how the Belt and Road Initiative(BRI)has affected the economic convergence of the Central Asian Turkic Republics,China,Pakistan,and their major diplomatic partners in the Silk Road region.Using bet...This study looks at how the Belt and Road Initiative(BRI)has affected the economic convergence of the Central Asian Turkic Republics,China,Pakistan,and their major diplomatic partners in the Silk Road region.Using beta and sigma convergence models over a predetermined time frame,the research evaluates economic alignment trends statistically and looks into how trade openness,FDI,and human capital affect the convergence process.The research attempts to discover larger causes of convergence,such as institutional quality and geopolitical closeness,by combining econometric analysis with regional economic dynamics.The purpose of the results is to provide policy suggestions that will improve equitable and sustainable economic convergence inside the Silk Road circle,promoting international cooperation and growth.展开更多
In this paper,by utilizing the Marcinkiewicz-Zygmund inequality and Rosenthal-type inequality of negatively superadditive dependent(NSD)random arrays and truncated method,we investigate the complete f-moment convergen...In this paper,by utilizing the Marcinkiewicz-Zygmund inequality and Rosenthal-type inequality of negatively superadditive dependent(NSD)random arrays and truncated method,we investigate the complete f-moment convergence of NSD random variables.We establish and improve a general result on the complete f-moment convergence for Sung’s type randomly weighted sums of NSD random variables under some general assumptions.As an application,we show the complete consistency for the randomly weighted estimator in a nonparametric regression model based on NSD errors.展开更多
The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the...The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the equivalent conditions of complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space.The results complement the corresponding results in probability space to those for sequences of independent,identically distributed random variables under sublinear expectation space.展开更多
The harmonic balance method(HBM)has been widely applied to get the periodic solution of nonlinear systems,however,its convergence rate as well as computation efficiency is dramatically degraded when the system is high...The harmonic balance method(HBM)has been widely applied to get the periodic solution of nonlinear systems,however,its convergence rate as well as computation efficiency is dramatically degraded when the system is highly non-smooth,e.g.,discontinuous.In order to accelerate the convergence,an enriched HBM is developed in this paper where the non-smooth Bernoulli bases are additionally introduced to enrich the conventional Fourier bases.The basic idea behind is that the convergence rate of the HB solution,as a truncated Fourier series,can be improved if the smoothness of the solution becomes finer.Along this line,using non-smooth Bernoulli bases can compensate the highly non-smooth part of the solution and then,the smoothness of the residual part for Fourier approximation is improved so as to achieve accelerated convergence.Numerical examples are conducted on systems with non-smooth restoring and/or external forces.The results confirm that the proposed enriched HBM indeed increases the convergence rate and the increase becomes more significant if more non-smooth bases are used.展开更多
In this paper,the convergence of the split-step theta method for stochastic differential equations is analyzed using stochastic C-stability and stochastic B-consistency.The fact that the numerical scheme,which is both...In this paper,the convergence of the split-step theta method for stochastic differential equations is analyzed using stochastic C-stability and stochastic B-consistency.The fact that the numerical scheme,which is both stochastically C-stable and stochastically B-consistent,is convergent has been proved in a previous paper.In order to analyze the convergence of the split-step theta method(θ∈[1/2,1]),the stochastic C-stability and stochastic B-consistency under the condition of global monotonicity have been researched,and the rate of convergence 1/2 has been explored in this paper.It can be seen that the convergence does not require the drift function should satisfy the linear growth condition whenθ=1/2 Furthermore,the rate of the convergence of the split-step scheme for stochastic differential equations with additive noise has been researched and found to be 1.Finally,an example is given to illustrate the convergence with the theoretical results.展开更多
This study investigates the convergence hypothesis and stochastic dynamics of agricultural land use and ecological balance across 13 major agricultural countries from 1992 to 2022.The study's concentrated samples ...This study investigates the convergence hypothesis and stochastic dynamics of agricultural land use and ecological balance across 13 major agricultural countries from 1992 to 2022.The study's concentrated samples are Russia,the United States,the Netherlands,Brazil,Germany,China,France,Spain,Italy,Canada,Belgium,Indonesia,and India.The research uncovers notable variations in ecological balance by utilizing a comprehensive set of advanced panel unit root tests(Panel CIPS,CADF,Panel-LM,Panel-KPSS,and Bahmani-Oskooee et al.’s Panel KPSS Unit Root Test).The findings highlight significant improvements in Canada,contrasting with declines in the Netherlands,France,Germany,and the United States.The results indicate convergence in ecological balance among these countries,suggesting that agricultural practices are progressively aligning with sustainability objectives.The considered countries can determine and enact joint and collective policy actions addressing cropland sustainability.However,the univariate outcome also shows that the cropland ecological balance of Germany,China,France,Indonesia,and India does contain a unit root and stationary which means the presence of the constant-mean.The univariate actions from the mentioned governments will not promote persistent impact.Therefore,joint actions determined by the countries considered are recommended for the mentioned countries.However,the rest of the countries also enact local policies.The insights gained are critical for informing global sustainability strategies and aiding policymakers in developing effective measures to enhance agricultural practices and mitigate environmental impacts.This research provides a data-driven foundation for optimizing agricultural sustainability and supports international efforts to achieve long-term ecological stability.展开更多
In this paper,for generalized two-dimensional delay space-fractional Fisher equations with mixed boundary conditions,we present the stability and convergence computed by a novel numerical method.The unconditional stab...In this paper,for generalized two-dimensional delay space-fractional Fisher equations with mixed boundary conditions,we present the stability and convergence computed by a novel numerical method.The unconditional stability of analytic solutions is first derived.Next,we have established the linearθ-method with the Grünwald-Letnikov operator,which has the first-order accuracy in spatial dimensions.Moreover,approaches involved error estimations and inequality reductions are utilized to prove the stability and convergence of numerical solutions under different values ofθ.Eventually,we implement a numerical experiment to validate theoretical conclusions,where the interaction impacts of fractional derivatives have been further analyzed by applying two different harmonic operators.展开更多
Designing novel van der Waals layered materials with low thermal conductivity and large power factor is important for the development of layered thermoelectric materials.Therefore,the novel van der Waals intercalated ...Designing novel van der Waals layered materials with low thermal conductivity and large power factor is important for the development of layered thermoelectric materials.Therefore,the novel van der Waals intercalated compound La_(2)Bi_(4)Cu_(2)O_(6)Se_(4),which is constructed by alternately stacking LaCuSeO and Bi_(2)O_(2)Se units along the c-axis in a 1:2 ratio,has designed for thermoelectric materials.The unique intercalated strategy leads to the four-band convergence at the valence band maximum,and the combination of multiple heavy band and light band,which significantly enhances the p-type doping power factor.The lattice thermal conductivities in La_(2)Bi_(4)Cu_(2)O_(6)Se_(4)and LaCuSeO compounds are accurately calculated by considering the coherence contributions of the anharmonic phonon reformulations and the off-diagonal term of the heat flux operator.The weak bond property of the Cu d-Se p bonding causes phonon softening,reducing the lattice thermal conductivity.The intercalated Bi atom has stereochemically active lone-pair electrons,which causes acoustic-optical coupling and produces strong fourth acoustic-optical phonon scattering,suppressing low-frequency phonon transport.The carrier relaxation time is rationalized by considering multiple carrier scattering mechanisms.The p-type doping La_(2)Bi_(4)Cu_(2)O_(6)Se_(4)achieves an average ZT of 2.3 at 700 K,and an optimal ZT of 2.7 along the in-plane direction.Our current work not only reveals the origin of the strong phonon scattering and large power factor of La_(2)Bi_(4)Cu_(2)O_(6)Se_(4)compound,but also provides theoretical guidance for the design of La-based layered oxides for thermoelectric applications.展开更多
Island-arc magmatism is a crucial process in the Earth’s crustal growth.However,how the island-arc magma production rate(MPR)changes and the key influencing factors remains unclear.This study employs numerical models...Island-arc magmatism is a crucial process in the Earth’s crustal growth.However,how the island-arc magma production rate(MPR)changes and the key influencing factors remains unclear.This study employs numerical models to simulate island-arc growth,incorporating slab dehydration,mantle hydration and melting,and melt extraction.In addition,the impacts of convergence rate and slab dip angle on island-arc magma production were studied.Results suggest that,(1)MPR increases with higher convergence rates;high convergence rates enhance slab water transport efficiency and mantle wedge convection,thereby promoting water fraction and temperature in potential molten regions;(2)MPR initially rises and then falls as the slab dip angle varies from 30°to 45°,and to 60°.This variation is closely tied to water content in the wedge rather than mantle temperature.However,a higher slab dip promotes dehydration towards the potential-melting mantle wedge,which causes water to ascend to shallow areas and reduces the area of the potential molten region.Ultimately,a dip angle of 45°is optimal for retaining the most suitable water fraction and mantle wedge area,thereby maintaining the largest MPR;(3)convergence rate variation has a much larger influence on magma production rate than dip angle variation.When the convergence rate varies from 2 to 10 cm/a,the largest time-averaged MPR is 64.0 times the smallest one,whereas when the slab dip varies from 30°to 60°,the largest time-averaged MPR is only 3.5 times the smallest one.These findings align with numerous instances observed in modern-day subduction zones.展开更多
Hypertrophic cardiomyopathy(HCM)is a primary myocardial disease characterized by myocardial hypertrophy,excluding other cardiovascular or systemic/metabolic causes of ventricular wall thickening.Apical hypertrophic ca...Hypertrophic cardiomyopathy(HCM)is a primary myocardial disease characterized by myocardial hypertrophy,excluding other cardiovascular or systemic/metabolic causes of ventricular wall thickening.Apical hypertrophic cardiomyopathy(ApHCM)represents a special form of ventricular hypertrophy predominantly affecting the left ventricular apex below the papillary muscles,typically without significant left ventricular outflow tract obstruction.[1,2]ApHCM often coexists with mild coronary artery abnormalities,[3]and reports of acute myocardial infarction with coronary artery stenosis in ApHCM or HCM patients are uncommon.展开更多
Assume that{a_(i),−∞<i<∞}is an absolutely summable sequence of real numbers.We establish the complete q-order moment convergence for the partial sums of moving average processes{X_(n)=Σ_(i=−∞)^(∞)a_(i)Y_(i+...Assume that{a_(i),−∞<i<∞}is an absolutely summable sequence of real numbers.We establish the complete q-order moment convergence for the partial sums of moving average processes{X_(n)=Σ_(i=−∞)^(∞)a_(i)Y_(i+n),n≥1}under some proper conditions,where{Yi,-∞<i<∞}is a doubly infinite sequence of negatively dependent random variables under sub-linear expectations.These results extend and complement the relevant results in probability space.展开更多
The rapid development of Internet technology has made“Internet+”a hallmark of the current era.The transformation and development of traditional media into all-media have provided a guiding direction for the developm...The rapid development of Internet technology has made“Internet+”a hallmark of the current era.The transformation and development of traditional media into all-media have provided a guiding direction for the development of campus media.The traditional form of campus media,which mainly consists of campus newspapers and campus radio,can no longer meet the application demands of modern higher education for media.In line with the current media convergence environment,campus media need to actively innovate to achieve their own development and progress in keeping with the times.This article explores the innovation path of campus media in the context of media convergence,analyzing the promotion of campus media innovation by the development of new media,the diversification of campus media innovation,and the effective ways of campus media innovation,in order to promote the realization of the innovation and development goals of campus media in the context of media convergence.展开更多
In this study,we present a deterministic convergence analysis of Gated Recurrent Unit(GRU)networks enhanced by a smoothing L_(1)regularization technique.While GRU architectures effectively mitigate gradient vanishing/...In this study,we present a deterministic convergence analysis of Gated Recurrent Unit(GRU)networks enhanced by a smoothing L_(1)regularization technique.While GRU architectures effectively mitigate gradient vanishing/exploding issues in sequential modeling,they remain prone to overfitting,particularly under noisy or limited training data.Traditional L_(1)regularization,despite enforcing sparsity and accelerating optimization,introduces non-differentiable points in the error function,leading to oscillations during training.To address this,we propose a novel smoothing L_(1)regularization framework that replaces the non-differentiable absolute function with a quadratic approximation,ensuring gradient continuity and stabilizing the optimization landscape.Theoretically,we rigorously establish threekey properties of the resulting smoothing L_(1)-regularizedGRU(SL_(1)-GRU)model:(1)monotonic decrease of the error function across iterations,(2)weak convergence characterized by vanishing gradients as iterations approach infinity,and(3)strong convergence of network weights to fixed points under finite conditions.Comprehensive experiments on benchmark datasets-spanning function approximation,classification(KDD Cup 1999 Data,MNIST),and regression tasks(Boston Housing,Energy Efficiency)-demonstrate SL_(1)-GRUs superiority over baseline models(RNN,LSTM,GRU,L_(1)-GRU,L2-GRU).Empirical results reveal that SL_(1)-GRU achieves 1.0%-2.4%higher test accuracy in classification,7.8%-15.4%lower mean squared error in regression compared to unregularized GRU,while reducing training time by 8.7%-20.1%.These outcomes validate the method’s efficacy in balancing computational efficiency and generalization capability,and they strongly corroborate the theoretical calculations.The proposed framework not only resolves the non-differentiability challenge of L_(1)regularization but also provides a theoretical foundation for convergence guarantees in recurrent neural network training.展开更多
This paper,grounded in the theory of business model innovation,examines the Chinese People’s Health Press(人民卫生出版社)as a case study to explore strategies for innovating business models within the context of prof...This paper,grounded in the theory of business model innovation,examines the Chinese People’s Health Press(人民卫生出版社)as a case study to explore strategies for innovating business models within the context of professional publishing convergence development.The research posits that effective business model innovation in this domain necessitates a comprehensive reform of its constituent elements.It advocates for a systematic approach to reconstructing value propositions,enhancing value creation and delivery processes,and optimizing value capture mechanisms to achieve desired outcomes.展开更多
The development of wind power clusters has scaled in terms of both scale and coverage,and the impact of weather fluctuations on cluster output changes has become increasingly complex.Accurately identifying the forward...The development of wind power clusters has scaled in terms of both scale and coverage,and the impact of weather fluctuations on cluster output changes has become increasingly complex.Accurately identifying the forward-looking information of key wind farms in a cluster under different weather conditions is an effective method to improve the accuracy of ultrashort-term cluster power forecasting.To this end,this paper proposes a refined modeling method for ultrashort-term wind power cluster forecasting based on a convergent cross-mapping algorithm.From the perspective of causality,key meteorological forecasting factors under different cluster power fluctuation processes were screened,and refined training modeling was performed for different fluctuation processes.First,a wind process description index system and classification model at the wind power cluster level are established to realize the classification of typical fluctuation processes.A meteorological-cluster power causal relationship evaluation model based on the convergent cross-mapping algorithm is pro-posed to screen meteorological forecasting factors under multiple types of typical fluctuation processes.Finally,a refined modeling meth-od for a variety of different typical fluctuation processes is proposed,and the strong causal meteorological forecasting factors of each scenario are used as inputs to realize high-precision modeling and forecasting of ultra-short-term wind cluster power.An example anal-ysis shows that the short-term wind power cluster power forecasting accuracy of the proposed method can reach 88.55%,which is 1.57-7.32%higher than that of traditional methods.展开更多
Comprehending regional characteristics and influencing factors of China＇s inbound tourism economy is im- portant to make effective policies that will help inbound tourism develop harmoniously and shrink regional disp...Comprehending regional characteristics and influencing factors of China＇s inbound tourism economy is im- portant to make effective policies that will help inbound tourism develop harmoniously and shrink regional disparity. This paper studied the regional disparity and convergence of China＇s inbound tourism economy during 1996-2008 with the methods of a-convergence, club convergence and r-convergence. The results indicate that 1） inbound tourism receipts per capita （ITRPC） of the whole country, the eastern, central and western regions presented the rapid increasing trend; 2） ITRPC of the whole country was characterized by convergence; 3） the eastern region presented club con- vergence, but the central and western regions did not show this trend; 4） the star-hotel levels and investment in fixed assets for the tourism industry per capita had a same trend to growth rates of ITRPC, promoting inbound tourism de- velopment, and there was no difference among the 31 provinces （municipalities） in the mainland of China; 5） but the proportion of employed persons in the tourism industry accounting for total population and the proportion of the terti- ary industry accounting for GDP had a reversal trend to growth rates of ITRPC, shrinking the provincial disparity in inbound tourism economy, and there were differences between the developed provinces and the developing provinces. Based on these analyses, we put forward some suggestions for the developing provinces to speed up inbound tourism economy.展开更多
We are interested in the convergence rates of the submartingale Wn=Z_(n)/Π_(n)to its limit W,where(Π_(n))is the usually used norming sequence and(Z_(n))is a supercritical branching process with immigration(Y_(n))in ...We are interested in the convergence rates of the submartingale Wn=Z_(n)/Π_(n)to its limit W,where(Π_(n))is the usually used norming sequence and(Z_(n))is a supercritical branching process with immigration(Y_(n))in a stationary and ergodic environmentξ.Under suitable conditions,we establish the following central limit theorems and results about the rates of convergence in probability or in law:(i)W-W_(n) with suitable normalization converges to the normal law N(0,1),and similar results also hold for W_(n+k)-W_(n) for each fixed k∈N^(*);(ii)for a branching process with immigration in a finite state random environment,if W_(1) has a finite exponential moment,then so does W,and the decay rate of P(|W-W_(n)|>ε)is supergeometric;(iii)there are normalizing constants an(ξ)(that we calculate explicitly)such that a_(n)(ξ)(W-W_(n))converges in law to a mixture of the Gaussian law.展开更多
The article deals with the waiting time process of the GI/G/1 queueing system.We shall give that the rate of convergence to the stationary distribution and the decay of the stationary tail only depend on the tail of t...The article deals with the waiting time process of the GI/G/1 queueing system.We shall give that the rate of convergence to the stationary distribution and the decay of the stationary tail only depend on the tail of the service distribution,but not on the interarrival distribution.We shall also give explicit criteria for the rate of convergence and decay of stationary tail for three specific types of subgeometric cases（Case 1：the rate function r（n）=exp（sn1/1＋α）,α〉0,s〉0;Case 2：polynomial rate function r（n）=nα,α〉0;Case 3：logarithmic rate function r（n）=logαn,α〉0）.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.12071175,12471183 and 12531009)。
文摘This note concerns the rapid uniform convergence of Cesàro weighted Birkhoff averages via irrational rotations on tori under certain conditions,involving arbitrary polynomial and exponential convergence rates.We discuss both finite dimensional and infinite dimensional cases,and give Diophantine rotations as examples.These provide the universality of rapid convergence for Cesàro weighted type,which is quite different from Lp(p>1)convergence for the unweighted one.We also show a certain optimality about our convergence rate.Besides,we introduce a multimodal weighted approach to adapt to the data sparsity,which still preserves exponential convergence.
文摘This study looks at how the Belt and Road Initiative(BRI)has affected the economic convergence of the Central Asian Turkic Republics,China,Pakistan,and their major diplomatic partners in the Silk Road region.Using beta and sigma convergence models over a predetermined time frame,the research evaluates economic alignment trends statistically and looks into how trade openness,FDI,and human capital affect the convergence process.The research attempts to discover larger causes of convergence,such as institutional quality and geopolitical closeness,by combining econometric analysis with regional economic dynamics.The purpose of the results is to provide policy suggestions that will improve equitable and sustainable economic convergence inside the Silk Road circle,promoting international cooperation and growth.
基金supported by the National Social Science Fundation(Grant No.21BTJ040)the Project of Outstanding Young People in University of Anhui Province(Grant Nos.2023AH020037,SLXY2024A001).
文摘In this paper,by utilizing the Marcinkiewicz-Zygmund inequality and Rosenthal-type inequality of negatively superadditive dependent(NSD)random arrays and truncated method,we investigate the complete f-moment convergence of NSD random variables.We establish and improve a general result on the complete f-moment convergence for Sung’s type randomly weighted sums of NSD random variables under some general assumptions.As an application,we show the complete consistency for the randomly weighted estimator in a nonparametric regression model based on NSD errors.
基金supported by Doctoral Scientific Research Starting Foundation of Jingdezhen Ceramic University(Grant No.102/01003002031)Re-accompanying Funding Project of Academic Achievements of Jingdezhen Ceramic University(Grant Nos.215/20506277,215/20506341)。
文摘The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the equivalent conditions of complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space.The results complement the corresponding results in probability space to those for sequences of independent,identically distributed random variables under sublinear expectation space.
基金supported by the National Natural Science Foundation of China (Grant No. 12372028)the National Key Research and Development Program of China (Grant No. 2020YFC2201101)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2022A1515011809)。
文摘The harmonic balance method(HBM)has been widely applied to get the periodic solution of nonlinear systems,however,its convergence rate as well as computation efficiency is dramatically degraded when the system is highly non-smooth,e.g.,discontinuous.In order to accelerate the convergence,an enriched HBM is developed in this paper where the non-smooth Bernoulli bases are additionally introduced to enrich the conventional Fourier bases.The basic idea behind is that the convergence rate of the HB solution,as a truncated Fourier series,can be improved if the smoothness of the solution becomes finer.Along this line,using non-smooth Bernoulli bases can compensate the highly non-smooth part of the solution and then,the smoothness of the residual part for Fourier approximation is improved so as to achieve accelerated convergence.Numerical examples are conducted on systems with non-smooth restoring and/or external forces.The results confirm that the proposed enriched HBM indeed increases the convergence rate and the increase becomes more significant if more non-smooth bases are used.
基金Supported by the National Natural Science Foundation of China (Grant No. 12301521)the Natural Science Foundation of Shanxi Province (Grant No. 20210302124081)。
文摘In this paper,the convergence of the split-step theta method for stochastic differential equations is analyzed using stochastic C-stability and stochastic B-consistency.The fact that the numerical scheme,which is both stochastically C-stable and stochastically B-consistent,is convergent has been proved in a previous paper.In order to analyze the convergence of the split-step theta method(θ∈[1/2,1]),the stochastic C-stability and stochastic B-consistency under the condition of global monotonicity have been researched,and the rate of convergence 1/2 has been explored in this paper.It can be seen that the convergence does not require the drift function should satisfy the linear growth condition whenθ=1/2 Furthermore,the rate of the convergence of the split-step scheme for stochastic differential equations with additive noise has been researched and found to be 1.Finally,an example is given to illustrate the convergence with the theoretical results.
文摘This study investigates the convergence hypothesis and stochastic dynamics of agricultural land use and ecological balance across 13 major agricultural countries from 1992 to 2022.The study's concentrated samples are Russia,the United States,the Netherlands,Brazil,Germany,China,France,Spain,Italy,Canada,Belgium,Indonesia,and India.The research uncovers notable variations in ecological balance by utilizing a comprehensive set of advanced panel unit root tests(Panel CIPS,CADF,Panel-LM,Panel-KPSS,and Bahmani-Oskooee et al.’s Panel KPSS Unit Root Test).The findings highlight significant improvements in Canada,contrasting with declines in the Netherlands,France,Germany,and the United States.The results indicate convergence in ecological balance among these countries,suggesting that agricultural practices are progressively aligning with sustainability objectives.The considered countries can determine and enact joint and collective policy actions addressing cropland sustainability.However,the univariate outcome also shows that the cropland ecological balance of Germany,China,France,Indonesia,and India does contain a unit root and stationary which means the presence of the constant-mean.The univariate actions from the mentioned governments will not promote persistent impact.Therefore,joint actions determined by the countries considered are recommended for the mentioned countries.However,the rest of the countries also enact local policies.The insights gained are critical for informing global sustainability strategies and aiding policymakers in developing effective measures to enhance agricultural practices and mitigate environmental impacts.This research provides a data-driven foundation for optimizing agricultural sustainability and supports international efforts to achieve long-term ecological stability.
基金supported by the National Natural Science Foundation of China(No.11201084).
文摘In this paper,for generalized two-dimensional delay space-fractional Fisher equations with mixed boundary conditions,we present the stability and convergence computed by a novel numerical method.The unconditional stability of analytic solutions is first derived.Next,we have established the linearθ-method with the Grünwald-Letnikov operator,which has the first-order accuracy in spatial dimensions.Moreover,approaches involved error estimations and inequality reductions are utilized to prove the stability and convergence of numerical solutions under different values ofθ.Eventually,we implement a numerical experiment to validate theoretical conclusions,where the interaction impacts of fractional derivatives have been further analyzed by applying two different harmonic operators.
基金Financial supports from the National Natural Science Foundation of China(Grant No.21503039)Department of Science and Technology of Liaoning Province(Grant No.2019MS164)+1 种基金Department of Education of Liaoning Province(Grant No.LJ2020JCL034)Discipline Innovation Team of Liaoning Technical University(Grant No.LNTU20TD-16)are greatly acknowledged。
文摘Designing novel van der Waals layered materials with low thermal conductivity and large power factor is important for the development of layered thermoelectric materials.Therefore,the novel van der Waals intercalated compound La_(2)Bi_(4)Cu_(2)O_(6)Se_(4),which is constructed by alternately stacking LaCuSeO and Bi_(2)O_(2)Se units along the c-axis in a 1:2 ratio,has designed for thermoelectric materials.The unique intercalated strategy leads to the four-band convergence at the valence band maximum,and the combination of multiple heavy band and light band,which significantly enhances the p-type doping power factor.The lattice thermal conductivities in La_(2)Bi_(4)Cu_(2)O_(6)Se_(4)and LaCuSeO compounds are accurately calculated by considering the coherence contributions of the anharmonic phonon reformulations and the off-diagonal term of the heat flux operator.The weak bond property of the Cu d-Se p bonding causes phonon softening,reducing the lattice thermal conductivity.The intercalated Bi atom has stereochemically active lone-pair electrons,which causes acoustic-optical coupling and produces strong fourth acoustic-optical phonon scattering,suppressing low-frequency phonon transport.The carrier relaxation time is rationalized by considering multiple carrier scattering mechanisms.The p-type doping La_(2)Bi_(4)Cu_(2)O_(6)Se_(4)achieves an average ZT of 2.3 at 700 K,and an optimal ZT of 2.7 along the in-plane direction.Our current work not only reveals the origin of the strong phonon scattering and large power factor of La_(2)Bi_(4)Cu_(2)O_(6)Se_(4)compound,but also provides theoretical guidance for the design of La-based layered oxides for thermoelectric applications.
基金Supported by the National Natural Science Foundation of China(Nos.42176068,42476063,92058213,42376081,42121005)。
文摘Island-arc magmatism is a crucial process in the Earth’s crustal growth.However,how the island-arc magma production rate(MPR)changes and the key influencing factors remains unclear.This study employs numerical models to simulate island-arc growth,incorporating slab dehydration,mantle hydration and melting,and melt extraction.In addition,the impacts of convergence rate and slab dip angle on island-arc magma production were studied.Results suggest that,(1)MPR increases with higher convergence rates;high convergence rates enhance slab water transport efficiency and mantle wedge convection,thereby promoting water fraction and temperature in potential molten regions;(2)MPR initially rises and then falls as the slab dip angle varies from 30°to 45°,and to 60°.This variation is closely tied to water content in the wedge rather than mantle temperature.However,a higher slab dip promotes dehydration towards the potential-melting mantle wedge,which causes water to ascend to shallow areas and reduces the area of the potential molten region.Ultimately,a dip angle of 45°is optimal for retaining the most suitable water fraction and mantle wedge area,thereby maintaining the largest MPR;(3)convergence rate variation has a much larger influence on magma production rate than dip angle variation.When the convergence rate varies from 2 to 10 cm/a,the largest time-averaged MPR is 64.0 times the smallest one,whereas when the slab dip varies from 30°to 60°,the largest time-averaged MPR is only 3.5 times the smallest one.These findings align with numerous instances observed in modern-day subduction zones.
文摘Hypertrophic cardiomyopathy(HCM)is a primary myocardial disease characterized by myocardial hypertrophy,excluding other cardiovascular or systemic/metabolic causes of ventricular wall thickening.Apical hypertrophic cardiomyopathy(ApHCM)represents a special form of ventricular hypertrophy predominantly affecting the left ventricular apex below the papillary muscles,typically without significant left ventricular outflow tract obstruction.[1,2]ApHCM often coexists with mild coronary artery abnormalities,[3]and reports of acute myocardial infarction with coronary artery stenosis in ApHCM or HCM patients are uncommon.
基金Supported by the Academic Achievement Re-cultivation Projects of Jingdezhen Ceramic University(Grant Nos.215/20506341215/20506277)the Doctoral Scientific Research Starting Foundation of Jingdezhen Ceramic University(Grant No.102/01003002031)。
文摘Assume that{a_(i),−∞<i<∞}is an absolutely summable sequence of real numbers.We establish the complete q-order moment convergence for the partial sums of moving average processes{X_(n)=Σ_(i=−∞)^(∞)a_(i)Y_(i+n),n≥1}under some proper conditions,where{Yi,-∞<i<∞}is a doubly infinite sequence of negatively dependent random variables under sub-linear expectations.These results extend and complement the relevant results in probability space.
文摘The rapid development of Internet technology has made“Internet+”a hallmark of the current era.The transformation and development of traditional media into all-media have provided a guiding direction for the development of campus media.The traditional form of campus media,which mainly consists of campus newspapers and campus radio,can no longer meet the application demands of modern higher education for media.In line with the current media convergence environment,campus media need to actively innovate to achieve their own development and progress in keeping with the times.This article explores the innovation path of campus media in the context of media convergence,analyzing the promotion of campus media innovation by the development of new media,the diversification of campus media innovation,and the effective ways of campus media innovation,in order to promote the realization of the innovation and development goals of campus media in the context of media convergence.
基金supported by the National Science Fund for Distinguished Young Scholarship(No.62025602)National Natural Science Foundation of China(Nos.U22B2036,11931015)+2 种基金the Fok Ying-Tong Education Foundation China(No.171105)the Fundamental Research Funds for the Central Universities(No.G2024WD0151)in part by the Tencent Foundation and XPLORER PRIZE.
文摘In this study,we present a deterministic convergence analysis of Gated Recurrent Unit(GRU)networks enhanced by a smoothing L_(1)regularization technique.While GRU architectures effectively mitigate gradient vanishing/exploding issues in sequential modeling,they remain prone to overfitting,particularly under noisy or limited training data.Traditional L_(1)regularization,despite enforcing sparsity and accelerating optimization,introduces non-differentiable points in the error function,leading to oscillations during training.To address this,we propose a novel smoothing L_(1)regularization framework that replaces the non-differentiable absolute function with a quadratic approximation,ensuring gradient continuity and stabilizing the optimization landscape.Theoretically,we rigorously establish threekey properties of the resulting smoothing L_(1)-regularizedGRU(SL_(1)-GRU)model:(1)monotonic decrease of the error function across iterations,(2)weak convergence characterized by vanishing gradients as iterations approach infinity,and(3)strong convergence of network weights to fixed points under finite conditions.Comprehensive experiments on benchmark datasets-spanning function approximation,classification(KDD Cup 1999 Data,MNIST),and regression tasks(Boston Housing,Energy Efficiency)-demonstrate SL_(1)-GRUs superiority over baseline models(RNN,LSTM,GRU,L_(1)-GRU,L2-GRU).Empirical results reveal that SL_(1)-GRU achieves 1.0%-2.4%higher test accuracy in classification,7.8%-15.4%lower mean squared error in regression compared to unregularized GRU,while reducing training time by 8.7%-20.1%.These outcomes validate the method’s efficacy in balancing computational efficiency and generalization capability,and they strongly corroborate the theoretical calculations.The proposed framework not only resolves the non-differentiability challenge of L_(1)regularization but also provides a theoretical foundation for convergence guarantees in recurrent neural network training.
文摘This paper,grounded in the theory of business model innovation,examines the Chinese People’s Health Press(人民卫生出版社)as a case study to explore strategies for innovating business models within the context of professional publishing convergence development.The research posits that effective business model innovation in this domain necessitates a comprehensive reform of its constituent elements.It advocates for a systematic approach to reconstructing value propositions,enhancing value creation and delivery processes,and optimizing value capture mechanisms to achieve desired outcomes.
基金funded by the State Grid Science and Technology Project“Research on Key Technologies for Prediction and Early Warning of Large-Scale Offshore Wind Power Ramp Events Based on Meteorological Data Enhancement”(4000-202318098A-1-1-ZN).
文摘The development of wind power clusters has scaled in terms of both scale and coverage,and the impact of weather fluctuations on cluster output changes has become increasingly complex.Accurately identifying the forward-looking information of key wind farms in a cluster under different weather conditions is an effective method to improve the accuracy of ultrashort-term cluster power forecasting.To this end,this paper proposes a refined modeling method for ultrashort-term wind power cluster forecasting based on a convergent cross-mapping algorithm.From the perspective of causality,key meteorological forecasting factors under different cluster power fluctuation processes were screened,and refined training modeling was performed for different fluctuation processes.First,a wind process description index system and classification model at the wind power cluster level are established to realize the classification of typical fluctuation processes.A meteorological-cluster power causal relationship evaluation model based on the convergent cross-mapping algorithm is pro-posed to screen meteorological forecasting factors under multiple types of typical fluctuation processes.Finally,a refined modeling meth-od for a variety of different typical fluctuation processes is proposed,and the strong causal meteorological forecasting factors of each scenario are used as inputs to realize high-precision modeling and forecasting of ultra-short-term wind cluster power.An example anal-ysis shows that the short-term wind power cluster power forecasting accuracy of the proposed method can reach 88.55%,which is 1.57-7.32%higher than that of traditional methods.
基金Under the auspices of National Natural Science Foundation of China (No. 40971019)National Basic Research Program of China (No. 2007CB411501)
文摘Comprehending regional characteristics and influencing factors of China＇s inbound tourism economy is im- portant to make effective policies that will help inbound tourism develop harmoniously and shrink regional disparity. This paper studied the regional disparity and convergence of China＇s inbound tourism economy during 1996-2008 with the methods of a-convergence, club convergence and r-convergence. The results indicate that 1） inbound tourism receipts per capita （ITRPC） of the whole country, the eastern, central and western regions presented the rapid increasing trend; 2） ITRPC of the whole country was characterized by convergence; 3） the eastern region presented club con- vergence, but the central and western regions did not show this trend; 4） the star-hotel levels and investment in fixed assets for the tourism industry per capita had a same trend to growth rates of ITRPC, promoting inbound tourism de- velopment, and there was no difference among the 31 provinces （municipalities） in the mainland of China; 5） but the proportion of employed persons in the tourism industry accounting for total population and the proportion of the terti- ary industry accounting for GDP had a reversal trend to growth rates of ITRPC, shrinking the provincial disparity in inbound tourism economy, and there were differences between the developed provinces and the developing provinces. Based on these analyses, we put forward some suggestions for the developing provinces to speed up inbound tourism economy.
基金supported by the National Natural Science Foundation of China(11571052,11731012)the Hunan Provincial Natural Science Foundation of China(2018JJ2417)the Open Fund of Hunan Provincial Key Laboratory of Mathematical Modeling and Analysis in Engineering(2018MMAEZD02)。
文摘We are interested in the convergence rates of the submartingale Wn=Z_(n)/Π_(n)to its limit W,where(Π_(n))is the usually used norming sequence and(Z_(n))is a supercritical branching process with immigration(Y_(n))in a stationary and ergodic environmentξ.Under suitable conditions,we establish the following central limit theorems and results about the rates of convergence in probability or in law:(i)W-W_(n) with suitable normalization converges to the normal law N(0,1),and similar results also hold for W_(n+k)-W_(n) for each fixed k∈N^(*);(ii)for a branching process with immigration in a finite state random environment,if W_(1) has a finite exponential moment,then so does W,and the decay rate of P(|W-W_(n)|>ε)is supergeometric;(iii)there are normalizing constants an(ξ)(that we calculate explicitly)such that a_(n)(ξ)(W-W_(n))converges in law to a mixture of the Gaussian law.
基金partially supported by the Fundamental Research Funds for the Central Universities (BUPT2011RC0703)
文摘The article deals with the waiting time process of the GI/G/1 queueing system.We shall give that the rate of convergence to the stationary distribution and the decay of the stationary tail only depend on the tail of the service distribution,but not on the interarrival distribution.We shall also give explicit criteria for the rate of convergence and decay of stationary tail for three specific types of subgeometric cases（Case 1：the rate function r（n）=exp（sn1/1＋α）,α〉0,s〉0;Case 2：polynomial rate function r（n）=nα,α〉0;Case 3：logarithmic rate function r（n）=logαn,α〉0）.
