With the development of urban culture in modern Shanghai,Shanghai style(海派Haipai)has gradually formed its own features.As a crucial component of urban culture,modern mass media reflects the essence of Shanghai-style...With the development of urban culture in modern Shanghai,Shanghai style(海派Haipai)has gradually formed its own features.As a crucial component of urban culture,modern mass media reflects the essence of Shanghai-style culture in its development.Its modernity,commerciality,openness,and innovation display the cultural trait of keeping up with the times.During the Xianfeng and Tongzhi periods of the Qing Dynasty(1851-1875),Suzhou Pingtan(苏州评弹)was introduced to Shanghai due to the influence of the Taiping Rebellion(太平天国战争),and began its Shanghai-style evolution in the context of modern mass media.On the one hand,modern newspapers and electronic media became crucial tools for the promotion of Suzhou Pingtan performers;on the other hand,the daily lives,performing careers,and public images of these performers became focal points of media attention.Mass media facilitated the Shanghai-style development of Suzhou Pingtan,and through it,changes in commercial awareness,performance styles,artistic expressions,musical innovation,and the celebrity-like performers all reflected the process of Shanghai-style development in Pingtan art.展开更多
The place and placeness are believed to be a crucial perspective for comprehending the transformative dynamics of tourist destinations in the context of globalization and the rapid development of the tourism industry....The place and placeness are believed to be a crucial perspective for comprehending the transformative dynamics of tourist destinations in the context of globalization and the rapid development of the tourism industry.As the material carrier of language,linguistic landscape is an intermediary for people to endow emotions and personalities into the place,becoming an effective path for exploring the place-making in a certain area.Mogan Mountain is a famous national tourist resort,which is located in Mogan Mountain Town,Deqing County,Huzhou City,China.This is a good case area for studying the relationship between linguistic landscape and placemaking in tourist destinations.There are two theories that form the theoretical foundation of the study,namely the place and the geosemiotics.Firstly,the results showed the overall style of the linguistic landscape.Multilingual labelling(52.7%),official signs(55.3%),and standardized Chinese characters predominantly shaped the linguistic landscape,with English and other languages being complementary.Secondly,from the perspective of three dimensions of the geosemiotics framework,such as inscription,language preference,and placement position,we conduct a comprehensive semiotic analysis of the linguistic landscape,which encompasses diverse facets such as fonts,materials,shifts in state,text vectors,and symmetrical arrangements.Finally,we explore the influence of linguistic landscapes on the place-making of Mogan Mountain through the dimensions of location,locale,and sense of place.The information on linguistic landscapes indicates the geographical location.These linguistic landscapes play an important role in constructing the language order,nostalgic atmosphere,exotic atmosphere,and elegant and tasteful lifestyle of the public space in Mogan Mountain.Readers of linguistic landscapes,including tourists and residents,generate and identify with the unique sense of place in Mogan Mountain.These linguistic landscapes construct the destination placeness of Mogan Mountain that combines both foreign and nostalgic styles,and the integration of Chinese and Western cultures.It will help promote the image positioning of tourism destinations and have practical guiding significance for the tourism planning,landscape-making,language management,and other aspects of tourism destinations.展开更多
In our recent investigations of diatom diversity,we studied three species,namely,Skeletonema costatum,Skeletonema subsalsum,and Skeletonema potamos.Although they have been found frequently in Changjiang(Yangtze)River ...In our recent investigations of diatom diversity,we studied three species,namely,Skeletonema costatum,Skeletonema subsalsum,and Skeletonema potamos.Although they have been found frequently in Changjiang(Yangtze)River Basin,their morphological and molecular identification is difficult in taxonomy.Therefore,to integrate morphological and molecular biological approaches,we compared systematically their morphological characters and performed phylogenetic analysis.Twelve strains of Skeletonema were collected and isolated from Shanghai and Jiangsu,China,and their morphological characteristics were examined by light microscopy(LM)and the scanning electron microscopy(SEM).Based on morphological comparison,we determined that S.potamos is easy to distinguish from the other two species.The heavily silicified areolae,undulated or cleft distal ends of terminal fultoportula processes(TFPPs),absence of basal pores of fultoportula processes(FPPs),the rootlike protrusions of FPPs,and no interlocking connection are the stable characteristics that can be used to identify S.potamos.However,there are only two features that can distinguish S.costatum from S.subsalsum,namely the location of terminal rimoportulae(TRPs)and the distal shape of TFPPs.In addition,we amplified and sequenced nine common genetic markers from the strains,from which 101 sequences were obtained,constructed phylogenetic trees based on the nine genes and evaluated that seven genes can be used to identify S.potamos,and revealed that S.subsalsum is the closest known relative of S.costatum,and only ATP synthetase beta-subunit gene(atp B)is able to distinguish them from each other,which strongly support that it is an effective molecular marker for Skeletonema.This work provided a theoretical basis for the taxonomic study of Skeletonema.展开更多
We consider the singular Riemann problem for the rectilinear isentropic compressible Euler equations with discontinuous flux,more specifically,for pressureless flow on the left and polytropic flow on the right separat...We consider the singular Riemann problem for the rectilinear isentropic compressible Euler equations with discontinuous flux,more specifically,for pressureless flow on the left and polytropic flow on the right separated by a discontinuity x=x(t).We prove that this problem admits global Radon measure solutions for all kinds of initial data.The over-compressing condition on the discontinuity x=x(t)is not enough to ensure the uniqueness of the solution.However,there is a unique piecewise smooth solution if one proposes a slip condition on the right-side of the curve x=x(t)+0,in addition to the full adhesion condition on its left-side.As an application,we study a free piston problem with the piston in a tube surrounded initially by uniform pressureless flow and a polytropic gas.In particular,we obtain the existence of a piecewise smooth solution for the motion of the piston between a vacuum and a polytropic gas.This indicates that the singular Riemann problem looks like a control problem in the sense that one could adjust the condition on the discontinuity of the flux to obtain the desired flow field.展开更多
We propose an efficient scheme to produce ultrahigh-brightness tens of MeV electron beams by designing a density-tailored plasma to induce a wakefield in the weakly nonlinear regime with a moderate laser energy of 120...We propose an efficient scheme to produce ultrahigh-brightness tens of MeV electron beams by designing a density-tailored plasma to induce a wakefield in the weakly nonlinear regime with a moderate laser energy of 120 mJ.In this scheme,the second bucket of the wakefield can have a much lower phase velocity at the steep plasma density down-ramp than the first bucket and can be exploited to implement longitudinal electron injection at a lower laser intensity,leading to the generation of bright electron beams with ultralow emittance together with low energy spread.Three-dimensional particle-in-cell simulations are carried out and demonstrate that high-quality electron beams with a peak energy of 50 MeV,ultralow emittance of28 nm rad,energy spread of 1%,charge of 4.4 pC,and short duration less than 5 fs can be obtained within a 1-mm-long tailored plasma density,resulting in an ultrahigh six-dimensional brightness B6D,n of2×1017 A/m2/0.1%.By changing the density parameters,tunable bright electron beams with peak energies ranging from 5 to 70 MeV,a small emittance of B0.1 mm mrad,and a low energy spread at a few-percent level can be obtained.These bright MeV-class electron beams have a variety of potential applications,for example,as ultrafast electron probes for diffraction and imaging,in laboratory astrophysics,in coherent radiation source generation,and as injectors for GeV particle accelerators.展开更多
Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissue...Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.Methods:To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues,multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes.Then,T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice.Quantitative real-time polymerase chain reaction(qRT-PCR)and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds.Perception to taste substance was also studied using twobottle preference tests.Results:We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique.Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice.But qRT-PCR results revealed the changed expression profile of m Tas2rs gene in taste buds of these mutant mice.With two-bottle preference tests,these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105.In addition,these mutant mice showed a loss of taste perception to quinine dihydrochloride,denatonium benzoate,and cucurbitacin B(CuB).Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception.Conclusions:These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues.展开更多
Based on a combination of morphology and molecular data of ribosomal DNA genes,a new diatom genus Lineaperpetua gen.nov.Yu,You,Kociolek&Wang is described.The features that help define Lineaperpetua at the level of...Based on a combination of morphology and molecular data of ribosomal DNA genes,a new diatom genus Lineaperpetua gen.nov.Yu,You,Kociolek&Wang is described.The features that help define Lineaperpetua at the level of genus include:a tangentially undulated valve face;continuous cribra areolae on the valve interior consisting of pores arranged as strips;single rimoportula located inside the ring of marginal fultoportulae.Additionally,phylogenetic analysis based on nuclear small subunit(SSU)rDNA sequences and nuclear large subunit(LSU)rDNA gene placed the three strains of L.lacustris in a single,monophyletic clade at a considerable sequence distance from the other genera(Thalassiosira,Conticribra,Planktoniella,Shinodiscus,and other genera)belonging to Thalassiosirales.Despite the similarities with some species of Thalassiosira,Conticribra,and Spicaticribra,the suite of features found in Lineaperpetua differentiate it from these other genera.These molecular data and morphological characters suggest an affinity of the new genus to the Thalassiosiraceae.展开更多
Deep degradation of organic pollutants by sunlight-induced coupled photocatalytic and Fenton (photo-Fenton) reactions is of immense importance for water purification. In this work, we report a novel bifunctional catal...Deep degradation of organic pollutants by sunlight-induced coupled photocatalytic and Fenton (photo-Fenton) reactions is of immense importance for water purification. In this work, we report a novel bifunctional catalyst (Fe-PEI-CN) by codoping graphitic carbon nitride (CN) with polyethyleneimine ethoxylated (PEI) and Fe species, which demonstrated high activity during p-chlorophenol (p-ClPhOH) degradation via H_(2)O_(2) from the photocatalytic process. The relationship between the catalytic efficiency and the structure was explored using diff erent characterization methods. The Fe modification of CN was achieved through Fe-N coordination, which ensured high dispersion of Fe species and strong stability against leaching during liquid- phase reactions. The Fe modification initiated the Fenton reaction by activating H_(2)O_(2) into ·OH radicals for deep degradation of p-ClPhOH. In addition, it eff ectively promoted light absorption and photoelectron-hole (e-h ^(+) ) separation, corresponding to improved photocatalytic activity. On the other hand, PEI could significantly improve the ability of CN to generate H_(2)O_(2) through visible light photocatalysis. The maximum H_(2)O_(2) yield reached up to 102.6 μmol/L, which was 22 times higher than that of primitive CN. The cooperation of photocatalysis and the self-Fenton reaction has led to high-activity mineralizing organic pollutants with strong durability, indicating good potential for practical application in wastewater treatment.展开更多
A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward contr...A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward controller is a novel input rate-dependent neural network hysteresis inverse model,while the feedback controller is a proportion integration differentiation(PID)controller.In the proposed inverse model,an input ratedependent auxiliary inverse operator(RAIO)and output of the hysteresis construct the expanded input space(EIS)of the inverse model which transforms the hysteresis inverse with multi-valued mapping into single-valued mapping,and the wiping-out,rate-dependent and continuous properties of the RAIO are analyzed in theories.Based on the EIS method,a hysteresis neural network inverse model,namely the dynamic back propagation neural network(DBPNN)model,is established.Moreover,a hybrid compensation scheme for the PEAs is designed to compensate for the hysteresis.Finally,the proposed method,the conventional PID controller and the hybrid controller with the modified input rate-dependent Prandtl-Ishlinskii(MRPI)model are all applied in the experimental platform.Experimental results show that the proposed method has obvious superiorities in the performance of the system.展开更多
Bi-based perovskite ferroelectric thin films have wide applications in electronic devices due to their excellent ferroelectric properties.New Bi-based perovskite thin films Bi(Cu_(1/2)Ti_(1/2))O_(3)–PbTiO_(3)(BCT–PT...Bi-based perovskite ferroelectric thin films have wide applications in electronic devices due to their excellent ferroelectric properties.New Bi-based perovskite thin films Bi(Cu_(1/2)Ti_(1/2))O_(3)–PbTiO_(3)(BCT–PT) are deposited on Pt(111)/Ti/SiO_(2)/Si substrates in the present study by the traditional sol–gel method.Their structures and related ferroelectric and fatigue characteristics are studied in-depth.The BCT–PT thin films exhibit good crystallization within the phase-pure perovskite structure,besides,they have a predominant(100) orientation together with a dense and homogeneous microstructure.The remnant polarization(2P_(r)) values at 30 μC/cm^(2) and 16 μC/cm^(2) are observed in 0.1BCT–0.9PT and 0.2BCT–0.8PT thin films,respectively.More intriguingly,although the polarization values are not so high,0.2BCT–0.8PT thin films show outstanding polarization fatigue properties,with a high switchable polarization of 93.6% of the starting values after 10^(8) cycles,indicating promising applications in ferroelectric memories.展开更多
The rapid advancement in the miniaturization,integration,and intelligence of electronic devices has escalated the demand for customizable microsupercapacitors(MSCs)with high energy density.However,efficient microfabri...The rapid advancement in the miniaturization,integration,and intelligence of electronic devices has escalated the demand for customizable microsupercapacitors(MSCs)with high energy density.However,efficient microfabrication of safe and high‐energy MXene MSCs for integrating microelectronics remains a significant challenge due to the low voltage window in aqueous electrolytes(typically≤0.6 V)and limited areal mass loading of MXene microelectrodes.Here,we tackle these challenges by developing a highconcentration(18mol kg^(−1))“water‐in‐LiBr”(WiB)gel electrolyte for MXene symmetric MSCs(M‐SMSCs),demonstrating a record high voltage window of 1.8 V.Subsequently,additive‐free aqueous MXene ink with excellent rheological behavior is developed for three‐dimensional(3D)printing customizable all‐MXene microelectrodes on various substrates.Leveraging the synergy of a highvoltage WiB gel electrolyte and 3D‐printed microelectrodes,quasi‐solid‐state MSMSCs operating stably at 1.8 V are constructed,and achieve an ultrahigh areal energy density of 1772μWhcm^(−2)and excellent low‐temperature tolerance,with a long‐term operation at−40℃.Finally,by extending the 3D printing protocol,M‐SMSCs are integrated with humidity sensors on a single planar substrate,demonstrating their reliability in miniaturized integrated microsystems.展开更多
Metasurfaces in the long wave infrared(LWIR)spectrum hold great potential for applications in ther-mal imaging,atmospheric remote sensing,and target identification,among others.In this study,we designed and experiment...Metasurfaces in the long wave infrared(LWIR)spectrum hold great potential for applications in ther-mal imaging,atmospheric remote sensing,and target identification,among others.In this study,we designed and experimentally demonstrated a 4 mm size,all-silicon metasurface metalens with large depth of focus opera-tional across a broadband range from 9µm to 11.5µm.The experimental results confirm effective focusing and imaging capabilities of the metalens in LWIR region,thus paving the way for practical LWIR applications of met-alens technology.展开更多
The impact of structural stiffness on optical axis deviation poses a significant challenge in the design of equatorial telescope structures.A comprehensive analysis during the design process can reduce the reliance of...The impact of structural stiffness on optical axis deviation poses a significant challenge in the design of equatorial telescope structures.A comprehensive analysis during the design process can reduce the reliance of a telescope on advanced control technologies,thereby improving its economic feasibility.Although full-system finite element analyses are reliable,they are encumbered by significant time requirements and limitations in covering all possible telescope orientations.Therefore,we propose an efficient and comprehensive analytical method to evaluate the optical axis deviation of equatorial telescopes across a full range of angles.To address the challenge of ensuring that the analysis covers all possible positions of an equatorial telescope,based on a model from SiTian project,we analyze the optical axis deviations caused by the fork arm at 25 different angles and then use fitting methods to obtain results for all angles.Based on the analysis results of the optical axis deviation caused by the stiffness of the optical tube in the horizontal position,we derive the results for the tube at any position using geometric relationships.Finally,we calculate the coupling factors and combine these impacts.Furthermore,we identify six discrete feature points to reflect possible telescope orientations and conduct comprehensive finite element analyses.The results are in alignment with those acquired through a comprehensive computational approach.展开更多
Background:The stromal vascular fraction(SVF),a cluster of stem and progenitor cells isolated from adipose tissue,holds significant promise for application in regenerative medicine.However,the existing methods for SVF...Background:The stromal vascular fraction(SVF),a cluster of stem and progenitor cells isolated from adipose tissue,holds significant promise for application in regenerative medicine.However,the existing methods for SVF isolation are time-consuming and expensive.Thus,in this study,we explored a new method of SVF extrac-tion-ultrasound-assisted SVF isolation(USASI)-and compared the viability and characteristics of SVF isolated using different methods.Methods:SVF extraction methods using different combinations of ultrasound power,ultrasound time,collagenase dosage,and collagenase digestion time were compared with those of the control group(collagenase digestion method).The cell yield and vitality of the SVF were evaluated via cell counting and trypan blue staining.The cell components and immunophenotypes of freshly isolated SVF were analyzed using flow cytometry.The prolifer-ative capacity and differentiation potential of the SVF were also identified.Results:Ultrasonication at 95 W-20 kHz for 30 s followed by digestion with 0.15%collagenase for 30 min was identified as the most suitable parameter for the USASI method in isolating SVF,as recommended based on the evaluation of various tested conditions.The USASI method significantly reduced the collagenase dosage and shortened the digestion time.Compared to the collagenase digestion method,the USASI method had a higher cell yield and cell viability,with no adverse effects on cell components,proliferative capacity,or multipotential differentiation capacity.Conclusion:With reduced processing time,lower collagenase dosage,and increased cell yield without impairing the viability and characteristics of SVF,USASI holds the potential to emerge as a time-saving and cost-effective method for future clinical applications.展开更多
The participation of women in legislation is an important aspect and means of safeguarding women’s rights.Feminist theory,based on criticism of both the“citizenship identity theory as rights”and the“citizenship id...The participation of women in legislation is an important aspect and means of safeguarding women’s rights.Feminist theory,based on criticism of both the“citizenship identity theory as rights”and the“citizenship identity theory as responsibilities,”proposes the“citizenship identity theory as subjectivity.”Observing the current practice of women’s participation in legislation in China,two institutional safeguard principles can be summarized:the“minimum proportion”and the“influence evaluation.”However,each of these principles has its inherent limitations.Therefore,it is necessary to supplement them with the principle of“subjective participation”in a reflective manner.This principle requires women to participate substantively in the legislative process as subjects,express women’s needs and demands,input women’s perspectives and experiences,and reconstruct the distribution of rights and responsibilities in the existing legislation.The three principles complement each other and work together to comprehensively constitute the institutional structure of women’s participation in legislation,thereby promoting the reproduction of corresponding action structures.展开更多
The location ofγ-ray emission of blazars remains a contested topic,inspiring the development of numerous investigative techniques to address this issue.In this work,we analyzed Fermiγ-ray light curves in the GeV and...The location ofγ-ray emission of blazars remains a contested topic,inspiring the development of numerous investigative techniques to address this issue.In this work,we analyzed Fermiγ-ray light curves in the GeV and MeV bands,employing the discrete cross-correlation function method to discern time lags between the two bands.For 4C+21.35,Ton 599,B21420+32,and PKS 1510-089,we identified a time lag spanning several days,while for PKS 1441+25,the time lag was not statistically found.The results imply that the soft photons necessary for inverse Compton scattering predominantly originate from the dusty torus in the first four sources,whereas for PKS1441+25,they seem to be sourced mainly from the broad-line region.Further analysis of the opacity(τγγ)and the GeV spectra study supports the conclusion that the location of the dissipation region must be beyond the BLR to avoid significant absorption.Notably,for PKS 1441+25,the emission region is also posited to lie outside yet proximate to the BLR.The parameters of describing the emission region were obtained by fitting broadband spectral energy distribution with contemporaneous observation data.Our findings suggest that for the five TeV FSRQs,during Te V flaring events,the jet appears to maintain an equilibrium between the energy density of the magnetic field and that of the particles for all investigated sources,with the exceptions of 4C+21.35 and PKS1441+25.In terms of the overall jet power,particle energy is the dominant contributor,and the observed blazar radiation cannot be solely attributed to the magnetic field,except in the case of 4C+21.35.Consequently,magnetic reconnection is unlikely to be the primary mechanism behind particle acceleration in these systems.展开更多
We have developed a novel method for co-adding multiple under-sampled images that combines the iteratively reweighted least squares and divide-and-conquer algorithms.Our approach not only allows for the anti-aliasing ...We have developed a novel method for co-adding multiple under-sampled images that combines the iteratively reweighted least squares and divide-and-conquer algorithms.Our approach not only allows for the anti-aliasing of the images but also enables Point-Spread Function(PSF)deconvolution,resulting in enhanced restoration of extended sources,the highest peak signal-to-noise ratio,and reduced ringing artefacts.To test our method,we conducted numerical simulations that replicated observation runs of the China Space Station Telescope/the VLT Survey Telescope(VST)and compared our results to those obtained using previous algorithms.The simulation showed that our method outperforms previous approaches in several ways,such as restoring the profile of extended sources and minimizing ringing artefacts.Additionally,because our method relies on the inherent advantages of least squares fitting,it is more versatile and does not depend on the local uniformity hypothesis for the PSF.However,the new method consumes much more computation than the other approaches.展开更多
Infrared(IR)spectral energy distribution(SED)is the major tracer of protoplanetary disks.It was recently proposed to use the near-to-mid IR(or K-24)SED slopeαdefined between 2 and 24μm as a potential quantitative tr...Infrared(IR)spectral energy distribution(SED)is the major tracer of protoplanetary disks.It was recently proposed to use the near-to-mid IR(or K-24)SED slopeαdefined between 2 and 24μm as a potential quantitative tracer of disk age.We critically examine the viability of this idea and confront it with additional statistics of IR luminosities and SED shapes.We point out that,because the statistical properties of most of the complicated physical factors involved in disk evolution are still poorly understood in a quantitative sense,the only viable way is to assume them to be random so that an idealized“average disk”can be defined,which allows theαhistogram to trace its age.We confirm that the statistics of the zeroth order(luminosity),first order(slopeα),and second order characteristics(concavity)of the observed K-24 SEDs indeed carry useful information upon the evolutionary processes of the“average disk”.We also stress that intrinsic diversities in K-24 SED shapes and luminosities are always large at the level of individual stars so that the application of the evolutionary path of the“average disk”to individual stars must be done with care.The data of most curves in plots are provided on GitHub(Disk-age package https://github.com/starage/disk-age/).展开更多
Stocks in the Chinese stock market can be divided into ST stocks and normal stocks, so to prevent investors from buying potential ST stocks, this paper first performs SMOTEENN oversampling data preprocessing for the S...Stocks in the Chinese stock market can be divided into ST stocks and normal stocks, so to prevent investors from buying potential ST stocks, this paper first performs SMOTEENN oversampling data preprocessing for the ST stock category, and selects 139 financial indicators and technical factor as predictive features. Then, it combines the Boruta algorithm and Copula entropy method for feature selection, effectively improving the machine learning model’s performance in ST stock classification, with the AUC values of the two models reaching 98% on the test set. In the model selection and optimization, this paper uses six major models, including logistic regression, XGBoost, AdaBoost, LightGBM, Catboost, and MLP, for modeling and optimizes them using the Optuna framework. Ultimately, XGBoost model is selected as the best model because its AUC value exceeds 95% and its running time is less. Finally, the XGBoost model is explained using the SHAP theory and the interaction between features is discovered, further improving the model’s accuracy and AUC value by about 0.6%, verifying the effectiveness of the model.展开更多
This paper investigates a class of coupled neural networks with delays and ad-dresses the exponential synchronization problem using delay-compensatory impulsive control. Razumikhin-type inequalities involving some des...This paper investigates a class of coupled neural networks with delays and ad-dresses the exponential synchronization problem using delay-compensatory impulsive control. Razumikhin-type inequalities involving some destabilizing delayed impulse gains are proposed, along with a new delay-compensatory concept demonstrating two crucial roles in system stability. Based on the constructed inequalities and the introduced delay-compensatory concept, sufficient stability and synchronization criteria for globally exponential synchronization of coupled neural networks are provided. To address the exponential synchronization problem in coupled neural networks. Utilizing delay-compensatory impulsive control and Razumikhin-type inequalities. The Lyapunov function for coupled neural networks with delays and integral terms exhibits exponential estimates.展开更多
文摘With the development of urban culture in modern Shanghai,Shanghai style(海派Haipai)has gradually formed its own features.As a crucial component of urban culture,modern mass media reflects the essence of Shanghai-style culture in its development.Its modernity,commerciality,openness,and innovation display the cultural trait of keeping up with the times.During the Xianfeng and Tongzhi periods of the Qing Dynasty(1851-1875),Suzhou Pingtan(苏州评弹)was introduced to Shanghai due to the influence of the Taiping Rebellion(太平天国战争),and began its Shanghai-style evolution in the context of modern mass media.On the one hand,modern newspapers and electronic media became crucial tools for the promotion of Suzhou Pingtan performers;on the other hand,the daily lives,performing careers,and public images of these performers became focal points of media attention.Mass media facilitated the Shanghai-style development of Suzhou Pingtan,and through it,changes in commercial awareness,performance styles,artistic expressions,musical innovation,and the celebrity-like performers all reflected the process of Shanghai-style development in Pingtan art.
基金the National Natural Science Foundation of China (Grant No. 41971171)The National Social Science Foundation of China (Grant No. 21BYY098) for funding support
文摘The place and placeness are believed to be a crucial perspective for comprehending the transformative dynamics of tourist destinations in the context of globalization and the rapid development of the tourism industry.As the material carrier of language,linguistic landscape is an intermediary for people to endow emotions and personalities into the place,becoming an effective path for exploring the place-making in a certain area.Mogan Mountain is a famous national tourist resort,which is located in Mogan Mountain Town,Deqing County,Huzhou City,China.This is a good case area for studying the relationship between linguistic landscape and placemaking in tourist destinations.There are two theories that form the theoretical foundation of the study,namely the place and the geosemiotics.Firstly,the results showed the overall style of the linguistic landscape.Multilingual labelling(52.7%),official signs(55.3%),and standardized Chinese characters predominantly shaped the linguistic landscape,with English and other languages being complementary.Secondly,from the perspective of three dimensions of the geosemiotics framework,such as inscription,language preference,and placement position,we conduct a comprehensive semiotic analysis of the linguistic landscape,which encompasses diverse facets such as fonts,materials,shifts in state,text vectors,and symmetrical arrangements.Finally,we explore the influence of linguistic landscapes on the place-making of Mogan Mountain through the dimensions of location,locale,and sense of place.The information on linguistic landscapes indicates the geographical location.These linguistic landscapes play an important role in constructing the language order,nostalgic atmosphere,exotic atmosphere,and elegant and tasteful lifestyle of the public space in Mogan Mountain.Readers of linguistic landscapes,including tourists and residents,generate and identify with the unique sense of place in Mogan Mountain.These linguistic landscapes construct the destination placeness of Mogan Mountain that combines both foreign and nostalgic styles,and the integration of Chinese and Western cultures.It will help promote the image positioning of tourism destinations and have practical guiding significance for the tourism planning,landscape-making,language management,and other aspects of tourism destinations.
基金Supported by the National Natural Science Foundation of China(No.32170205)the Natural Science Foundation of Shanghai(No.21ZR144730)。
文摘In our recent investigations of diatom diversity,we studied three species,namely,Skeletonema costatum,Skeletonema subsalsum,and Skeletonema potamos.Although they have been found frequently in Changjiang(Yangtze)River Basin,their morphological and molecular identification is difficult in taxonomy.Therefore,to integrate morphological and molecular biological approaches,we compared systematically their morphological characters and performed phylogenetic analysis.Twelve strains of Skeletonema were collected and isolated from Shanghai and Jiangsu,China,and their morphological characteristics were examined by light microscopy(LM)and the scanning electron microscopy(SEM).Based on morphological comparison,we determined that S.potamos is easy to distinguish from the other two species.The heavily silicified areolae,undulated or cleft distal ends of terminal fultoportula processes(TFPPs),absence of basal pores of fultoportula processes(FPPs),the rootlike protrusions of FPPs,and no interlocking connection are the stable characteristics that can be used to identify S.potamos.However,there are only two features that can distinguish S.costatum from S.subsalsum,namely the location of terminal rimoportulae(TRPs)and the distal shape of TFPPs.In addition,we amplified and sequenced nine common genetic markers from the strains,from which 101 sequences were obtained,constructed phylogenetic trees based on the nine genes and evaluated that seven genes can be used to identify S.potamos,and revealed that S.subsalsum is the closest known relative of S.costatum,and only ATP synthetase beta-subunit gene(atp B)is able to distinguish them from each other,which strongly support that it is an effective molecular marker for Skeletonema.This work provided a theoretical basis for the taxonomic study of Skeletonema.
基金supported by the National Natural Science Foundation of China(11871218,12071298)in part by the Science and Technology Commission of Shanghai Municipality(21JC1402500,22DZ2229014)。
文摘We consider the singular Riemann problem for the rectilinear isentropic compressible Euler equations with discontinuous flux,more specifically,for pressureless flow on the left and polytropic flow on the right separated by a discontinuity x=x(t).We prove that this problem admits global Radon measure solutions for all kinds of initial data.The over-compressing condition on the discontinuity x=x(t)is not enough to ensure the uniqueness of the solution.However,there is a unique piecewise smooth solution if one proposes a slip condition on the right-side of the curve x=x(t)+0,in addition to the full adhesion condition on its left-side.As an application,we study a free piston problem with the piston in a tube surrounded initially by uniform pressureless flow and a polytropic gas.In particular,we obtain the existence of a piecewise smooth solution for the motion of the piston between a vacuum and a polytropic gas.This indicates that the singular Riemann problem looks like a control problem in the sense that one could adjust the condition on the discontinuity of the flux to obtain the desired flow field.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11974251,12105180,12074397,11904377,and 12005137)the Innovation Program of Shanghai Municipal Education Commission(Grant No.2021-01-07-00-02-E00118)the National Key Research and Development Program(Grant No.2023YFA1406804).
文摘We propose an efficient scheme to produce ultrahigh-brightness tens of MeV electron beams by designing a density-tailored plasma to induce a wakefield in the weakly nonlinear regime with a moderate laser energy of 120 mJ.In this scheme,the second bucket of the wakefield can have a much lower phase velocity at the steep plasma density down-ramp than the first bucket and can be exploited to implement longitudinal electron injection at a lower laser intensity,leading to the generation of bright electron beams with ultralow emittance together with low energy spread.Three-dimensional particle-in-cell simulations are carried out and demonstrate that high-quality electron beams with a peak energy of 50 MeV,ultralow emittance of28 nm rad,energy spread of 1%,charge of 4.4 pC,and short duration less than 5 fs can be obtained within a 1-mm-long tailored plasma density,resulting in an ultrahigh six-dimensional brightness B6D,n of2×1017 A/m2/0.1%.By changing the density parameters,tunable bright electron beams with peak energies ranging from 5 to 70 MeV,a small emittance of B0.1 mm mrad,and a low energy spread at a few-percent level can be obtained.These bright MeV-class electron beams have a variety of potential applications,for example,as ultrafast electron probes for diffraction and imaging,in laboratory astrophysics,in coherent radiation source generation,and as injectors for GeV particle accelerators.
基金Shanghai Science and Technology Commission“R&D Public Service Platform and Institutional Capacity Improvement Project”,Grant/Award Number:21DZ2291300National Science and Technology Major Project,Grant/Award Number:2017ZX10304402-001-006 and 2017ZX10304402-001-012Start-on Funding from Shanghai Public Health Clinical Center,Grant/Award Number:KY-GW-2019-11,KYGW-2019-19 and KY-GW-2021-39。
文摘Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.Methods:To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues,multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes.Then,T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice.Quantitative real-time polymerase chain reaction(qRT-PCR)and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds.Perception to taste substance was also studied using twobottle preference tests.Results:We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique.Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice.But qRT-PCR results revealed the changed expression profile of m Tas2rs gene in taste buds of these mutant mice.With two-bottle preference tests,these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105.In addition,these mutant mice showed a loss of taste perception to quinine dihydrochloride,denatonium benzoate,and cucurbitacin B(CuB).Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception.Conclusions:These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues.
基金the Postdoctoral Science Foundation of China(No.2021 M 703434)the National Natural Science Foundation of China(Nos.32100165,32170205)the Natural Science Foundation of Shanghai(No.21 ZR 144730)。
文摘Based on a combination of morphology and molecular data of ribosomal DNA genes,a new diatom genus Lineaperpetua gen.nov.Yu,You,Kociolek&Wang is described.The features that help define Lineaperpetua at the level of genus include:a tangentially undulated valve face;continuous cribra areolae on the valve interior consisting of pores arranged as strips;single rimoportula located inside the ring of marginal fultoportulae.Additionally,phylogenetic analysis based on nuclear small subunit(SSU)rDNA sequences and nuclear large subunit(LSU)rDNA gene placed the three strains of L.lacustris in a single,monophyletic clade at a considerable sequence distance from the other genera(Thalassiosira,Conticribra,Planktoniella,Shinodiscus,and other genera)belonging to Thalassiosirales.Despite the similarities with some species of Thalassiosira,Conticribra,and Spicaticribra,the suite of features found in Lineaperpetua differentiate it from these other genera.These molecular data and morphological characters suggest an affinity of the new genus to the Thalassiosiraceae.
基金the National Key Research and Development Program of China (No. 2020YFA0211004)Key Grant of Nation Science Funding of China (No. 22236005)+5 种基金Nation Science Funding of China (No. 22376141)Ministry of Education of China (No. PCSIRT_IRT_16R49)“111” Innovation and Talent Recruitment Base (D18020)Shanghai Government (No. 20ZR1440700)Shanghai Engineering Research Center of Green Energy Chemical Engineering (No. 18DZ2254200)Scientific and Technological Innovation Team for Green Catalysis and Energy Materialien Yunnan Institutions of Higher Learning, and Surface project of Yunnan Province science and technology Department (No. 20210 A070001-050).
文摘Deep degradation of organic pollutants by sunlight-induced coupled photocatalytic and Fenton (photo-Fenton) reactions is of immense importance for water purification. In this work, we report a novel bifunctional catalyst (Fe-PEI-CN) by codoping graphitic carbon nitride (CN) with polyethyleneimine ethoxylated (PEI) and Fe species, which demonstrated high activity during p-chlorophenol (p-ClPhOH) degradation via H_(2)O_(2) from the photocatalytic process. The relationship between the catalytic efficiency and the structure was explored using diff erent characterization methods. The Fe modification of CN was achieved through Fe-N coordination, which ensured high dispersion of Fe species and strong stability against leaching during liquid- phase reactions. The Fe modification initiated the Fenton reaction by activating H_(2)O_(2) into ·OH radicals for deep degradation of p-ClPhOH. In addition, it eff ectively promoted light absorption and photoelectron-hole (e-h ^(+) ) separation, corresponding to improved photocatalytic activity. On the other hand, PEI could significantly improve the ability of CN to generate H_(2)O_(2) through visible light photocatalysis. The maximum H_(2)O_(2) yield reached up to 102.6 μmol/L, which was 22 times higher than that of primitive CN. The cooperation of photocatalysis and the self-Fenton reaction has led to high-activity mineralizing organic pollutants with strong durability, indicating good potential for practical application in wastewater treatment.
基金National Natural Science Foundation of China(Nos.62171285,61971120 and 62327807)。
文摘A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward controller is a novel input rate-dependent neural network hysteresis inverse model,while the feedback controller is a proportion integration differentiation(PID)controller.In the proposed inverse model,an input ratedependent auxiliary inverse operator(RAIO)and output of the hysteresis construct the expanded input space(EIS)of the inverse model which transforms the hysteresis inverse with multi-valued mapping into single-valued mapping,and the wiping-out,rate-dependent and continuous properties of the RAIO are analyzed in theories.Based on the EIS method,a hysteresis neural network inverse model,namely the dynamic back propagation neural network(DBPNN)model,is established.Moreover,a hybrid compensation scheme for the PEAs is designed to compensate for the hysteresis.Finally,the proposed method,the conventional PID controller and the hybrid controller with the modified input rate-dependent Prandtl-Ishlinskii(MRPI)model are all applied in the experimental platform.Experimental results show that the proposed method has obvious superiorities in the performance of the system.
基金Project supported by the National Key Research and Development Program of China(Grant No.2021YFA1400300)the National Natural Science Foundation of China(Grant Nos.22271309,21805215,11934017,12261131499,and 11921004)+1 种基金the Beijing Natural Science Foundation(Grant No.Z200007)the Fund from the Chinese Academy of Sciences(Grant No.XDB33000000)。
文摘Bi-based perovskite ferroelectric thin films have wide applications in electronic devices due to their excellent ferroelectric properties.New Bi-based perovskite thin films Bi(Cu_(1/2)Ti_(1/2))O_(3)–PbTiO_(3)(BCT–PT) are deposited on Pt(111)/Ti/SiO_(2)/Si substrates in the present study by the traditional sol–gel method.Their structures and related ferroelectric and fatigue characteristics are studied in-depth.The BCT–PT thin films exhibit good crystallization within the phase-pure perovskite structure,besides,they have a predominant(100) orientation together with a dense and homogeneous microstructure.The remnant polarization(2P_(r)) values at 30 μC/cm^(2) and 16 μC/cm^(2) are observed in 0.1BCT–0.9PT and 0.2BCT–0.8PT thin films,respectively.More intriguingly,although the polarization values are not so high,0.2BCT–0.8PT thin films show outstanding polarization fatigue properties,with a high switchable polarization of 93.6% of the starting values after 10^(8) cycles,indicating promising applications in ferroelectric memories.
基金National Natural Science Foundation of China,Grant/Award Numbers:22005297,22125903,51872283,22209175,22209176National Key Research and Development Program of China,Grant/Award Number:2022YFA1504100+8 种基金Support Program for Excellent Young Talents in Universities of Anhui Province,Grant/Award Number:2022AH030134Anhui Province Higher Education Innovation Team:Key Technologies and Equipment Innovation Team for Clean Energy,Grant/Award Number:2023AH010055Strategic Priority Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDB36030200Dalian Innovation Support Plan for High Level Talents,Grant/Award Number:2019RT09Dalian National Laboratory for Clean Energy(DNL),CAS,DNL Cooperation Fund,CAS,Grant/Award Numbers:DNL202016,DNL202019,DNL202003DICP,Grant/Award Number:DICP I2020032Doctor Research Startup Foundation of Suzhou University,Grant/Award Number:2023BSK015China Postdoctoral Science Foundation,Grant/Award Numbers:2020M680995,2021M693127International Postdoctoral Exchange Fellowship Program,Grant/Award Number:YJ20210311。
文摘The rapid advancement in the miniaturization,integration,and intelligence of electronic devices has escalated the demand for customizable microsupercapacitors(MSCs)with high energy density.However,efficient microfabrication of safe and high‐energy MXene MSCs for integrating microelectronics remains a significant challenge due to the low voltage window in aqueous electrolytes(typically≤0.6 V)and limited areal mass loading of MXene microelectrodes.Here,we tackle these challenges by developing a highconcentration(18mol kg^(−1))“water‐in‐LiBr”(WiB)gel electrolyte for MXene symmetric MSCs(M‐SMSCs),demonstrating a record high voltage window of 1.8 V.Subsequently,additive‐free aqueous MXene ink with excellent rheological behavior is developed for three‐dimensional(3D)printing customizable all‐MXene microelectrodes on various substrates.Leveraging the synergy of a highvoltage WiB gel electrolyte and 3D‐printed microelectrodes,quasi‐solid‐state MSMSCs operating stably at 1.8 V are constructed,and achieve an ultrahigh areal energy density of 1772μWhcm^(−2)and excellent low‐temperature tolerance,with a long‐term operation at−40℃.Finally,by extending the 3D printing protocol,M‐SMSCs are integrated with humidity sensors on a single planar substrate,demonstrating their reliability in miniaturized integrated microsystems.
基金Supported by National Key R&D Program of China(2021YFA0715500)National Natural Science Foundation of China(NSFC)(12227901)+1 种基金Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB0580000)Chinese Academy of Sciences President's In-ternational Fellowship Initiative(2021PT0007).
文摘Metasurfaces in the long wave infrared(LWIR)spectrum hold great potential for applications in ther-mal imaging,atmospheric remote sensing,and target identification,among others.In this study,we designed and experimentally demonstrated a 4 mm size,all-silicon metasurface metalens with large depth of focus opera-tional across a broadband range from 9µm to 11.5µm.The experimental results confirm effective focusing and imaging capabilities of the metalens in LWIR region,thus paving the way for practical LWIR applications of met-alens technology.
文摘The impact of structural stiffness on optical axis deviation poses a significant challenge in the design of equatorial telescope structures.A comprehensive analysis during the design process can reduce the reliance of a telescope on advanced control technologies,thereby improving its economic feasibility.Although full-system finite element analyses are reliable,they are encumbered by significant time requirements and limitations in covering all possible telescope orientations.Therefore,we propose an efficient and comprehensive analytical method to evaluate the optical axis deviation of equatorial telescopes across a full range of angles.To address the challenge of ensuring that the analysis covers all possible positions of an equatorial telescope,based on a model from SiTian project,we analyze the optical axis deviations caused by the fork arm at 25 different angles and then use fitting methods to obtain results for all angles.Based on the analysis results of the optical axis deviation caused by the stiffness of the optical tube in the horizontal position,we derive the results for the tube at any position using geometric relationships.Finally,we calculate the coupling factors and combine these impacts.Furthermore,we identify six discrete feature points to reflect possible telescope orientations and conduct comprehensive finite element analyses.The results are in alignment with those acquired through a comprehensive computational approach.
基金supported by the National Natural Science Foundation of China(grant nos.81971848 and 82272287)Shanghai Municipal Key Clinical Specialty(grant no,shslczdzk00901)+2 种基金Clinical Research Plan of SHDC(rant nos.SHDC2020CR1019B and SHC2020CR402)Innovative Research Team of High-Level Local Universities in Shanghai(grant no.SSMU-ZDCX20180700)Shanghai Clinical Research Center of Plastic and Reconstructive Surgery supported by the Science and Technology Commission of Shanghai Municipality(grant no.22MC1940300).
文摘Background:The stromal vascular fraction(SVF),a cluster of stem and progenitor cells isolated from adipose tissue,holds significant promise for application in regenerative medicine.However,the existing methods for SVF isolation are time-consuming and expensive.Thus,in this study,we explored a new method of SVF extrac-tion-ultrasound-assisted SVF isolation(USASI)-and compared the viability and characteristics of SVF isolated using different methods.Methods:SVF extraction methods using different combinations of ultrasound power,ultrasound time,collagenase dosage,and collagenase digestion time were compared with those of the control group(collagenase digestion method).The cell yield and vitality of the SVF were evaluated via cell counting and trypan blue staining.The cell components and immunophenotypes of freshly isolated SVF were analyzed using flow cytometry.The prolifer-ative capacity and differentiation potential of the SVF were also identified.Results:Ultrasonication at 95 W-20 kHz for 30 s followed by digestion with 0.15%collagenase for 30 min was identified as the most suitable parameter for the USASI method in isolating SVF,as recommended based on the evaluation of various tested conditions.The USASI method significantly reduced the collagenase dosage and shortened the digestion time.Compared to the collagenase digestion method,the USASI method had a higher cell yield and cell viability,with no adverse effects on cell components,proliferative capacity,or multipotential differentiation capacity.Conclusion:With reduced processing time,lower collagenase dosage,and increased cell yield without impairing the viability and characteristics of SVF,USASI holds the potential to emerge as a time-saving and cost-effective method for future clinical applications.
基金a phased project of the “Research on the Principles of Argumentation of Ratio Legis (Reasons) in Local Legislation” (Project Approval Number 2023EFX002)a Youth Project of Shanghai Philosophy and Social Science Planning in 2023。
文摘The participation of women in legislation is an important aspect and means of safeguarding women’s rights.Feminist theory,based on criticism of both the“citizenship identity theory as rights”and the“citizenship identity theory as responsibilities,”proposes the“citizenship identity theory as subjectivity.”Observing the current practice of women’s participation in legislation in China,two institutional safeguard principles can be summarized:the“minimum proportion”and the“influence evaluation.”However,each of these principles has its inherent limitations.Therefore,it is necessary to supplement them with the principle of“subjective participation”in a reflective manner.This principle requires women to participate substantively in the legislative process as subjects,express women’s needs and demands,input women’s perspectives and experiences,and reconstruct the distribution of rights and responsibilities in the existing legislation.The three principles complement each other and work together to comprehensively constitute the institutional structure of women’s participation in legislation,thereby promoting the reproduction of corresponding action structures.
基金support from the National Natural Science Foundation of China(NSFC,Grant No.12203034)from the Shanghai Science and Technology Fund under grant No.22YF1431500+11 种基金from the science research grants from the China Manned Space Projectsupport from the National Natural Science Foundation of China(NSFC,grant No.12203043)support from the National Natural Science Foundation of China(NSFC,grant No.11933002)support from the National Natural Science Foundation of China(NSFC,grant No.12173026)the National Key Research and Development Program of China(grant No.2022YFC2807303)the Shanghai Science and Technology Fund(grant No.23010503900)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learningthe Shuguang Program(23SG39)of the Shanghai Education Development Foundation and Shanghai Municipal Education Commissionsupport from the National Natural Science Foundation of China(NSFC,grant No.U2031201,and 11733001)the Scientific and Technological Cooperation Projects(20202023)between the People’s Republic of China and the Republic of Bulgariathe science research grants from the China Manned Space Project with No.CMS-CSST-2021A06partially supported by the Bulgarian National Science Fund of the Ministry of Education and Science under grants KP-06-H38/4(2019),KP-06-KITAJ/2(2020),and KP-06-H68/4(2022)。
文摘The location ofγ-ray emission of blazars remains a contested topic,inspiring the development of numerous investigative techniques to address this issue.In this work,we analyzed Fermiγ-ray light curves in the GeV and MeV bands,employing the discrete cross-correlation function method to discern time lags between the two bands.For 4C+21.35,Ton 599,B21420+32,and PKS 1510-089,we identified a time lag spanning several days,while for PKS 1441+25,the time lag was not statistically found.The results imply that the soft photons necessary for inverse Compton scattering predominantly originate from the dusty torus in the first four sources,whereas for PKS1441+25,they seem to be sourced mainly from the broad-line region.Further analysis of the opacity(τγγ)and the GeV spectra study supports the conclusion that the location of the dissipation region must be beyond the BLR to avoid significant absorption.Notably,for PKS 1441+25,the emission region is also posited to lie outside yet proximate to the BLR.The parameters of describing the emission region were obtained by fitting broadband spectral energy distribution with contemporaneous observation data.Our findings suggest that for the five TeV FSRQs,during Te V flaring events,the jet appears to maintain an equilibrium between the energy density of the magnetic field and that of the particles for all investigated sources,with the exceptions of 4C+21.35 and PKS1441+25.In terms of the overall jet power,particle energy is the dominant contributor,and the observed blazar radiation cannot be solely attributed to the magnetic field,except in the case of 4C+21.35.Consequently,magnetic reconnection is unlikely to be the primary mechanism behind particle acceleration in these systems.
基金supported by the GHfund A(202302017475)supported by the Foundation for Distinguished Young Scholars of Jiangsu Province(No.BK20140050)+5 种基金the National Natural Science Foundation of China(Nos.11973070,11333008,11273061,11825303,and 11673065)the China Manned Space Project with No.CMS-CSST-2021-A01,CMSCSST-2021-A03,CMS-CSST-2021-B01the Joint Funds of the National Natural Science Foundation of China(No.U1931210)the support from Key Research Program of Frontier Sciences,CAS,grant No.ZDBS-LY-7013Program of Shanghai Academic/Technology Research Leaderthe support from the science research grants from the China Manned Space Project with CMS-CSST-2021-A04,CMS-CSST-2021-A07。
文摘We have developed a novel method for co-adding multiple under-sampled images that combines the iteratively reweighted least squares and divide-and-conquer algorithms.Our approach not only allows for the anti-aliasing of the images but also enables Point-Spread Function(PSF)deconvolution,resulting in enhanced restoration of extended sources,the highest peak signal-to-noise ratio,and reduced ringing artefacts.To test our method,we conducted numerical simulations that replicated observation runs of the China Space Station Telescope/the VLT Survey Telescope(VST)and compared our results to those obtained using previous algorithms.The simulation showed that our method outperforms previous approaches in several ways,such as restoring the profile of extended sources and minimizing ringing artefacts.Additionally,because our method relies on the inherent advantages of least squares fitting,it is more versatile and does not depend on the local uniformity hypothesis for the PSF.However,the new method consumes much more computation than the other approaches.
基金supported by the Natural Science Foundation of Yunnan Province(No.202201 BC070003)supported by the ANID FONDECYT Postdoctoral program No.3220029+2 种基金support by ANID,—Millennium Science Initiative Program—NCN19_171sponsored(in part)by the Chinese Academy of Sciences(CAS)the CAS South America Center for Astronomy(CASSACA)in Santiago,Chile.
文摘Infrared(IR)spectral energy distribution(SED)is the major tracer of protoplanetary disks.It was recently proposed to use the near-to-mid IR(or K-24)SED slopeαdefined between 2 and 24μm as a potential quantitative tracer of disk age.We critically examine the viability of this idea and confront it with additional statistics of IR luminosities and SED shapes.We point out that,because the statistical properties of most of the complicated physical factors involved in disk evolution are still poorly understood in a quantitative sense,the only viable way is to assume them to be random so that an idealized“average disk”can be defined,which allows theαhistogram to trace its age.We confirm that the statistics of the zeroth order(luminosity),first order(slopeα),and second order characteristics(concavity)of the observed K-24 SEDs indeed carry useful information upon the evolutionary processes of the“average disk”.We also stress that intrinsic diversities in K-24 SED shapes and luminosities are always large at the level of individual stars so that the application of the evolutionary path of the“average disk”to individual stars must be done with care.The data of most curves in plots are provided on GitHub(Disk-age package https://github.com/starage/disk-age/).
文摘Stocks in the Chinese stock market can be divided into ST stocks and normal stocks, so to prevent investors from buying potential ST stocks, this paper first performs SMOTEENN oversampling data preprocessing for the ST stock category, and selects 139 financial indicators and technical factor as predictive features. Then, it combines the Boruta algorithm and Copula entropy method for feature selection, effectively improving the machine learning model’s performance in ST stock classification, with the AUC values of the two models reaching 98% on the test set. In the model selection and optimization, this paper uses six major models, including logistic regression, XGBoost, AdaBoost, LightGBM, Catboost, and MLP, for modeling and optimizes them using the Optuna framework. Ultimately, XGBoost model is selected as the best model because its AUC value exceeds 95% and its running time is less. Finally, the XGBoost model is explained using the SHAP theory and the interaction between features is discovered, further improving the model’s accuracy and AUC value by about 0.6%, verifying the effectiveness of the model.
文摘This paper investigates a class of coupled neural networks with delays and ad-dresses the exponential synchronization problem using delay-compensatory impulsive control. Razumikhin-type inequalities involving some destabilizing delayed impulse gains are proposed, along with a new delay-compensatory concept demonstrating two crucial roles in system stability. Based on the constructed inequalities and the introduced delay-compensatory concept, sufficient stability and synchronization criteria for globally exponential synchronization of coupled neural networks are provided. To address the exponential synchronization problem in coupled neural networks. Utilizing delay-compensatory impulsive control and Razumikhin-type inequalities. The Lyapunov function for coupled neural networks with delays and integral terms exhibits exponential estimates.