Objective:Cancer survivors have experienced subjective cognitive impairment(SCI)when they received cancer diagnoses or treatments.Their psychosocial and emotional statuses were also impacted.With the advancement of we...Objective:Cancer survivors have experienced subjective cognitive impairment(SCI)when they received cancer diagnoses or treatments.Their psychosocial and emotional statuses were also impacted.With the advancement of web technologies,web-based cognitive interventions have been implemented in the management and the alleviation of the SCI,the psychosocial distress,and the emotional distress in cancer survivors.This review aimed to summarize the intervention contents of web-based cognitive interventions for SCI,and to explore the effects of the interventions on SCI,psychosocial status,and emotional health.Methods:Six databases(CINAHL Plus,Cochrane Library,Embase,APA PsycInfo,PubMed and CNKI)were searched from the establishment of databases up to December 2023.Literature references were also manually searched for related articles.Results:This review contained 21 studies that covered the contents of web-based cognitive interventions,such as computer-assisted cognitive training,online cognitive rehabilitation,cognitive behavior therapy with the Internet,telehealth physical exercise,and web-based mindfulness interventions.The effects of web-based cognitive interventions positively impacted SCI for cancer survivors.Also,these interventions showed varying degrees of effectiveness in alleviating psychosocial and emotional distresses.Conclusion:By summarizingfive types of cognitive intervention contents delivered via web technology,this review demonstrated that web-based cognitive interventions optimized SCI and overall psychosocial and emotional statuses for the cancer survivors.It is recommended that future research focus on the development of customized web-based cognitive interventions for individuals with SCI,along with their psychosocial and emotional statuses.展开更多
Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale pr...Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale proposed in this work are used to simulate the thermal conductivity behaviors of the 3D C/SiC composites.An entirely new process is introduced to weave the preform with three-dimensional orthogonal architecture.The 3D steady-state analysis step is created for assessing the thermal conductivity behaviors of the composites by applying periodic temperature boundary conditions.Three RVE models of cuboid,hexagonal and fiber random distribution are respectively developed to comparatively study the influence of fiber package pattern on the thermal conductivities at the microscale.Besides,the effect of void morphology on the thermal conductivity of the matrix is analyzed by the void/matrix models.The prediction results at the mesoscale correspond closely to the experimental values.The effect of the porosities and fiber volume fractions on the thermal conductivities is also taken into consideration.The multi-scale models mentioned in this paper can be used to predict the thermal conductivity behaviors of other composites with complex structures.展开更多
This paper provides a study on the stability and time-step constraints of solving the linearized Korteweg-de Vries(KdV)equation,using implicit-explicit(IMEX)Runge-Kutta(RK)time integration methods combined with either...This paper provides a study on the stability and time-step constraints of solving the linearized Korteweg-de Vries(KdV)equation,using implicit-explicit(IMEX)Runge-Kutta(RK)time integration methods combined with either finite difference(FD)or local discontinuous Galerkin(DG)spatial discretization.We analyze the stability of the fully discrete scheme,on a uniform mesh with periodic boundary conditions,using the Fourier method.For the linearized KdV equation,the IMEX schemes are stable under the standard Courant-Friedrichs-Lewy(CFL)conditionτ≤λh.Here,λis the CFL number,τis the time-step size,and h is the spatial mesh size.We study several IMEX schemes and characterize their CFL number as a function ofθ=d/h^(2)with d being the dispersion coefficient,which leads to several interesting observations.We also investigate the asymptotic behaviors of the CFL number for sufficiently refined meshes and derive the necessary conditions for the asymptotic stability of the IMEX-RK methods.Some numerical experiments are provided in the paper to illustrate the performance of IMEX methods under different time-step constraints.展开更多
The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the...The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.展开更多
The amino acid contents of five floral sources Chinese honeys(jujube, rape, chaste, acacia, and lungan) were measured using reversed phase high-performance liquid chromatography(RP-HPLC). The results showed that proli...The amino acid contents of five floral sources Chinese honeys(jujube, rape, chaste, acacia, and lungan) were measured using reversed phase high-performance liquid chromatography(RP-HPLC). The results showed that proline was the main amino acid in most of the analyzed samples. Phenylalanine presents at the highest content in chaste honey samples, and the total amino acid contents of chaste honeys were also significantly higher than those of other honey samples. Based on the amino acid contents, honey samples were classified using chemometric methods(cluster analysis(CA), principal component analysis(PCA), and discriminant analysis(DA)). According to the CA results, chaste honeys could be separated from other honeys, while the remaining samples were correctly grouped together when the chaste honey data were excluded. By using DA, the overall correct classification rate reached 100%. The results revealed that amino acid contents could potentially be used as indicators to identify the botanical origin of unifloral honeys.展开更多
Polymer nanocomposites have been investigated for about three decades. To get deep insights into the modifying effects of various nanofillers on mechanical and physical properties of polymer nanocomposites, the three ...Polymer nanocomposites have been investigated for about three decades. To get deep insights into the modifying effects of various nanofillers on mechanical and physical properties of polymer nanocomposites, the three basic aspects of processing, characterization and properties are critically reviewed in this paper. Nanofillers can be classified into three major types of two-dimensional (2D) layered, one-dimensional (1D) fibrous and zerodimensional (0D) spherical ones and this review thus discusses in detail the processing, characterization and properties of the three types of polymer nanocomposites. It starts with an introduction of various nanoscale fillers such as two-dimensional (2D) nano-clay, graphene and MXene, one dimensional (1D) carbon nanofibers and nanotubes, zero dimensional (0D) silica nanoparticles and ZnO quantum dots as well as nanofiller-polymer interfaces. The processing of these polymer nanocomposites using different methods and the characterization of nanofillers and polymer nanocomposites using various techniques are described. Finally, the mechanical and physical properties of these polymer nanocomposites are discussed by considering the effects of nanofiller type, dispersion and contents;also, interface properties show significant effects on the mechanical properties of polymer nanocomposites and are discussed in some details.展开更多
The two-dimensional infiltration experiment was carried out by means of digital image technology.The evolution process of the wetting body was described.The wetted front distance and the time show a very significant p...The two-dimensional infiltration experiment was carried out by means of digital image technology.The evolution process of the wetting body was described.The wetted front distance and the time show a very significant power function relationship.The horizontal wetted distance is larger than the vertical wetted distance in the initial stage.Then,the vertical distance of the wetted body gradually approaches to the horizontal distance.The infiltration distance decreases as the content of fine particles increases.The wetted front migration rate curve shows a three-stage change law,and it increases with the increase of coarse particle content.The directional velocity ratio is defined.The initial value of horizontal infiltration rate is larger than that of vertical one,and then the vertical infiltration rate is gradually close to the horizontal value.The empirical relationship between the characteristic particle size and the stable infiltration rate is established,which provides a theoretical basis for the prediction of the stable infiltration rate in in-situ leaching.展开更多
BACKGROUND Remote ischemic conditioning(RIC)is used to protect against myocardial injury.However,there is no adequate evidence for comprehensive RIC in elderly patients with ST-segment elevation myocardial infarction(...BACKGROUND Remote ischemic conditioning(RIC)is used to protect against myocardial injury.However,there is no adequate evidence for comprehensive RIC in elderly patients with ST-segment elevation myocardial infarction(STEMI).This study aimed to test whether comprehensive RIC,started pre-primary percutaneous coronary intervention(PPCI)and repeated daily on 1-30 days post-PPCI,can improve myocardial salvage index(SI),left ventricular ejection fraction(LVEF),Kansas City Cardiomyopathy Questionnaire Clinical Summary Score(KCCQ-CSS)and 6-min walk test distance(6MWD)in elderly patients with acute STEMI during 12 months follow-up.METHODS 328 consenting elderly patients were randomized to receive standard PPCI plus comprehensive RIC(the treatment group)or standard PPCI(the control group).SI at 5-7 days after PPCI,LVEF,left ventricular end-diastolic volume index(LVEDVI),left ventricular end-systolic volume index(LVESVI),KCCQ-CSS,6MWD and adverse events rates were measured and assessed.RESULTS SI was significantly higher in the treatment group[interquartile range(IQR):0.38-0.66,P=0.037].There were no significant differences in major adverse events at 12 months.Although the differences of LVEDVI,LVESVI and LVEF between the treatment group and the control group did not reach statistical significance at 6 months and 12 months,LVEF tended to be higher,LVEDVI tended to be lower in the treatment group.The KCCQ-CSS was significantly higher in the treatment group at 1 month(IQR:46.5-87,P=0.001)and 12 months(IQR:55-93,P=0.008).There was significant difference in 6MWD between the treatment group and the control group(IQR:258-360 vs.IQR:250-345,P=0.002)at 1 month and(IQR:360-445 vs.IQR:345-432,P=0.035)at 12 months.A modest correlation was found between SI and LVEF(r=0.452,P<0.01),KCCQ-CSS(r=0.440,P<0.01)and 6MWD(r=0.384,P<0.01)respectively at 12 months.CONCLUSIONS The comprehensive RIC can improve SI,KCCQ-CSS and 6MWD.It may be an adjunctive therapy to PPCI in elderly patients with STEMI.展开更多
In this work,a flowing material balance equation(FMBE) is established for under saturated coalbed methane(CBM) reservoirs,which considers immobile free gas expansion effect at the dewatering stage.Based on the establi...In this work,a flowing material balance equation(FMBE) is established for under saturated coalbed methane(CBM) reservoirs,which considers immobile free gas expansion effect at the dewatering stage.Based on the established FMBE,five straight-line methods are proposed to determine the control area,initial water reserve,initial free gas reserve,initial adsorbed gas reserve,original gas in place,as well as permeability at the same time.Subsequently,the proposed FMBE methods for undersaturated CBM reservoirs are validated against a reservoir simulation software with and without considering free gas expansion.Finally,the proposed methods are applied in a field case when considering free gas expansion effect.Validation cases show that the straight-line relationships for the proposed five FMBE methods are excellent,and good agreements are obtained among the actual reserves and permeabilities and those evaluated by the proposed five FMBE methods,indicating the proposed five FMBE methods are effective and rational for CBM reservoirs.Results show that a small amount of free gas will result in a great deviation in reserve evaluation;hence,the immobile free gas expansion effect should be considered when establishing the material balance equation of undersaturated CBM reservoirs at the dewatering stage.展开更多
Codon usage bias varies considerably among genomes and even within the genes of the same genome. In eukaryotic organisms, energy production in the form of oxidative phosphorylation (OXPHOS) is the only process under...Codon usage bias varies considerably among genomes and even within the genes of the same genome. In eukaryotic organisms, energy production in the form of oxidative phosphorylation (OXPHOS) is the only process under control of both nuclear and mitochondrial genomes. Although factors affecting codon usage in a single genome have been studied, this has not occurred when both interactional genomes are involved. Consequently, we investigated whether or not other factors influence codon usage of coevolved genes. We used Drosophila melanogaster as a model organism. Our χ^2 test on the number of codons of nuclear and mitochondrial genes involved in the OXPHOS system was significantly different (χ^2= 7945.16, P 〈 0.01). A plot of effective number of codons against GC3s content of nuclear genes showed that few genes lie on the expected curve, indicating that codon usage was random. Correspondence analysis indicated a significant correlation between axis 1 and codon adaptation index (R = 0.947, P 〈 0.01) in every nuclear gene sequence. Thus, codon usage bias of nuclear genes appeared to be affected by translational selection. Correlation between axis 1 coordinates and GC content (R = 0.814, P 〈 0.01) indicated that the codon usage of nuclear genes was also affected by GC composition. Analysis of mitochondrial genes did not reveal a significant correlation between axis 1 and any parameter. Statistical analyses indicated that codon usages of both nDNA and mtDNA were subjected to context-dependent mutations.展开更多
In the present work, the TIPS behavior of isotactic polypropylene(iP P)/di-n-butyl phthalate(DBP)/dioctyl phthalate(DOP)/nano-SiO_2 system and the competition relation between liquid–liquid phase separation and polym...In the present work, the TIPS behavior of isotactic polypropylene(iP P)/di-n-butyl phthalate(DBP)/dioctyl phthalate(DOP)/nano-SiO_2 system and the competition relation between liquid–liquid phase separation and polymer crystallization are successfully adjusted by adding nano-SiO_2. The liquid–liquid phase separation temperature of the system increases with increasing nano-SiO_2 content. Besides, iP P crystallization temperature is also changed after adding nano-SiO_2. IPP/nano-SiO_2 blend hollow fiber microporous membrane is prepared via TIPS method. SEM photos show that the membrane exhibits mixed morphology combining cellular structure relating to liquid–liquid phase separation and branch structure originating from polymer crystallization. The relative weight of cellular structure first decreases and then increases with the increase of nano-SiO_2 content. Furthermore, porosity, connectivity among pores and pure water flux of the membrane first increase and then decrease with increasing nano-SiO_2 content. However, mechanical performance of the membrane is improved at all times with increasing nano-SiO_2 content.展开更多
Path planning is a key technique of autonomous navigation for robots,and the velocity field is an important part.Constructing velocity field in a complex workspace is still challenging.In this paper,an inner normal gu...Path planning is a key technique of autonomous navigation for robots,and the velocity field is an important part.Constructing velocity field in a complex workspace is still challenging.In this paper,an inner normal guided segmentation algorithm in a complex polygon is proposed to decompose the complex workspace in this paper.The artificial potential field model based on probability theory is then used to calculate the potential field of the decomposed workspace,and the velocity field is obtained by utilizing the potential field of this workspace.Path optimization is implemented by curve evolution,during which the internal force generated in the smoothing process of the initial path by a mean filter and the external force is obtained from the gradient of the workspace potential field.The parameter selection principle is deduced by analyzing the influence of several parameters on the path length and smoothness.Simulation results show that the designed polygon decomposition algorithm can effectively segment complex workspace and that the path optimization algorithm can shorten and smoothen paths.展开更多
Advanced machine learning(ML)approaches such as transfer learning have seldom been applied to approximate quantum many-body systems.Here we demonstrate that a simple recurrent unit(SRU)based efficient and transferable...Advanced machine learning(ML)approaches such as transfer learning have seldom been applied to approximate quantum many-body systems.Here we demonstrate that a simple recurrent unit(SRU)based efficient and transferable sequence learning framework is capable of learning and accurately predicting the time evolution of the one-dimensional(ID)Ising model with simultaneous transverse and parallel magnetic fields,as quantitatively corroborated by relative entropy measurements between the predicted and exact state distributions.At a cost of constant computational complexity,a larger many-body state evolution is predicted in an autoregressive way from just one initial state,without any guidance or knowledge of any Hamiltonian.Our work paves the way for future applications of advanced ML methods in quantum many-body dynamics with knowledge only from a smaller system.展开更多
A time discretization method is called strongly stable(or monotone),if the norm of its numerical solution is nonincreasing.Although this property is desirable in various of contexts,many explicit Runge-Kutta(RK)method...A time discretization method is called strongly stable(or monotone),if the norm of its numerical solution is nonincreasing.Although this property is desirable in various of contexts,many explicit Runge-Kutta(RK)methods may fail to preserve it.In this paper,we enforce strong stability by modifying the method with superviscosity,which is a numerical technique commonly used in spectral methods.Our main focus is on strong stability under the inner-product norm for linear problems with possibly non-normal operators.We propose two approaches for stabilization:the modified method and the filtering method.The modified method is achieved by modifying the semi-negative operator with a high order superviscosity term;the filtering method is to post-process the solution by solving a diffusive or dispersive problem with small superviscosity.For linear problems,most explicit RK methods can be stabilized with either approach without accuracy degeneration.Furthermore,we prove a sharp bound(up to an equal sign)on diffusive superviscosity for ensuring strong stability.For nonlinear problems,a filtering method is investigated.Numerical examples with linear non-normal ordinary differential equation systems and for discontinuous Galerkin approximations of conservation laws are performed to validate our analysis and to test the performance.展开更多
This paper presents a combination method of Particle Swarm Optimization (PSO) and topology optimization. With this method a better result can be achieved compared with the sequential application of these two optimizat...This paper presents a combination method of Particle Swarm Optimization (PSO) and topology optimization. With this method a better result can be achieved compared with the sequential application of these two optimization methods. It inherits the ability in finding global optimum from PSO and also suits for discretized design domain. Some special schemes are used in order to provide higher computation efficiency. This method has only been tested with a convex optimization problem. The application in case of a concave problem will be a future study.展开更多
Objective:The aim of this study was to investigate the potential ability of medicated serum of Erzhi pills on growth,proliferation and inflammation of the human breast cancer cell line MCF-7 cells.Methods:3-month-old ...Objective:The aim of this study was to investigate the potential ability of medicated serum of Erzhi pills on growth,proliferation and inflammation of the human breast cancer cell line MCF-7 cells.Methods:3-month-old female Sprague–Dawley rats were used to prepared medicated serum,and randomly assigned into four groups:control group(distillated water),low doses(2.25g/kg/d),middle doses(4.5g/kg/d),high does(9.0g/kg/d).The growth curve was meas-ured by MTT method,the proliferation was examined by colony formation assay.Inflam-matory cytokines IL-1β,IL-18 and IL-6 was detected by Quantitative real time polymerase chain reaction(RT-qPCR).Western blot was used to examine the expression of NF-kB signal pathway.Results:The medicated serum of Erzhi pills could inhibit the growth and proliferation of breast cancer cell MCF-7,especially,in the group of middle doses and high does(P<0.05).The protein expression of IKKα,IκBαand p-NF-κB were significantly down regulated.As well as the mRNA expression levels of Inflammatory cytokine,such as IL-1β,IL-18 and IL-6,were decreased.Conclusion:Medicated serum of Erzhi pills played an anti-tumor role in breast cancer via inhibiting the growth and proliferation of MCF-7.Moreover,Erzhi pills could suppress in-flammatory responses from the NFκB signaling pathways,and reduced skeletal muscle pain caused by breast cancer endocrine therapy,and Erzhi pills may be a new target for the treatment of breast cancer.展开更多
Objective:To explore the diagnostic value of traditional Chinese medical(TCM)dialectical classification in Hashimoto's thyroiditis complicated with suspicious nodules.Methods:The clinical data of patients with Has...Objective:To explore the diagnostic value of traditional Chinese medical(TCM)dialectical classification in Hashimoto's thyroiditis complicated with suspicious nodules.Methods:The clinical data of patients with Hashimoto's thyroiditis complicated with thyroid nodules in the Department of Breast and thyroid surgery of Weifang Hospital of traditional Chinese Medicine from January 2018 to December 2019 were collected.The patients were examined by 2 or more experienced TCM doctors,and the four diagnostic data were obtained,and then the relevant syndrome types of the patients were judged according to the data.According to the color Doppler ultrasonographic features of thyroid nodules,the patients who met the indication of fine needle aspiration biopsy of thyroid nodules were selected and underwent fine needle aspiration biopsy of thyroid nodules before operation.To analyze the clinical diagnostic value of that the ultrasonic mode used in this study and thyroid cytopathology Bethesda report system combine dialectical classification of traditional Chinese medicine in Hashimoto's thyroiditis complicated with suspected thyroid nodules.Result:A total of 89 patients with Hashimoto's thyroiditis complicated with thyroid nodules were collected.according to the ultrasonic mode,the difference between different modes was statistically significant(P<0.05).The mode of color ultrasound is also related to the dialectical classification of traditional Chinese medicine.The patients with high malignant risk score are mainly qi depression and phlegm stagnation,phlegm and blood stasis,while those with low score are exuberant liver fire and heart liver yin deficiency.According to the study of different The Bethesda System for Reporting Thyroid Cytopathology(TBSRTC)classification,the dialectical classification of patients with higher TBSRTC classification was more inclined to qi depression and phlegm stagnation,phlegm and blood stasis,and there was significant difference between different classification(P<0.05).Conclusion:Qi depression and phlegm obstruction,phlegm and blood stasis have high ultrasound malignant risk score and high TBSRTC classification grade in patients with Hashimoto's thyroiditis complicated with suspected thyroid nodules,which has important clinical diagnostic value.展开更多
基金The National Natural Science Foundation of China supports this review(No.82172844)The funder had no role in study design,data collection and analysis,manuscript preparation,or decision to publish.
文摘Objective:Cancer survivors have experienced subjective cognitive impairment(SCI)when they received cancer diagnoses or treatments.Their psychosocial and emotional statuses were also impacted.With the advancement of web technologies,web-based cognitive interventions have been implemented in the management and the alleviation of the SCI,the psychosocial distress,and the emotional distress in cancer survivors.This review aimed to summarize the intervention contents of web-based cognitive interventions for SCI,and to explore the effects of the interventions on SCI,psychosocial status,and emotional health.Methods:Six databases(CINAHL Plus,Cochrane Library,Embase,APA PsycInfo,PubMed and CNKI)were searched from the establishment of databases up to December 2023.Literature references were also manually searched for related articles.Results:This review contained 21 studies that covered the contents of web-based cognitive interventions,such as computer-assisted cognitive training,online cognitive rehabilitation,cognitive behavior therapy with the Internet,telehealth physical exercise,and web-based mindfulness interventions.The effects of web-based cognitive interventions positively impacted SCI for cancer survivors.Also,these interventions showed varying degrees of effectiveness in alleviating psychosocial and emotional distresses.Conclusion:By summarizingfive types of cognitive intervention contents delivered via web technology,this review demonstrated that web-based cognitive interventions optimized SCI and overall psychosocial and emotional statuses for the cancer survivors.It is recommended that future research focus on the development of customized web-based cognitive interventions for individuals with SCI,along with their psychosocial and emotional statuses.
基金Supported by Science Center for Gas Turbine Project of China (Grant No.P2022-B-IV-014-001)Frontier Leading Technology Basic Research Special Project of Jiangsu Province of China (Grant No.BK20212007)the BIT Research and Innovation Promoting Project of China (Grant No.2022YCXZ019)。
文摘Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale proposed in this work are used to simulate the thermal conductivity behaviors of the 3D C/SiC composites.An entirely new process is introduced to weave the preform with three-dimensional orthogonal architecture.The 3D steady-state analysis step is created for assessing the thermal conductivity behaviors of the composites by applying periodic temperature boundary conditions.Three RVE models of cuboid,hexagonal and fiber random distribution are respectively developed to comparatively study the influence of fiber package pattern on the thermal conductivities at the microscale.Besides,the effect of void morphology on the thermal conductivity of the matrix is analyzed by the void/matrix models.The prediction results at the mesoscale correspond closely to the experimental values.The effect of the porosities and fiber volume fractions on the thermal conductivities is also taken into consideration.The multi-scale models mentioned in this paper can be used to predict the thermal conductivity behaviors of other composites with complex structures.
基金supported by the NSF under Grant DMS-2208391sponsored by the NSF under Grant DMS-1753581.
文摘This paper provides a study on the stability and time-step constraints of solving the linearized Korteweg-de Vries(KdV)equation,using implicit-explicit(IMEX)Runge-Kutta(RK)time integration methods combined with either finite difference(FD)or local discontinuous Galerkin(DG)spatial discretization.We analyze the stability of the fully discrete scheme,on a uniform mesh with periodic boundary conditions,using the Fourier method.For the linearized KdV equation,the IMEX schemes are stable under the standard Courant-Friedrichs-Lewy(CFL)conditionτ≤λh.Here,λis the CFL number,τis the time-step size,and h is the spatial mesh size.We study several IMEX schemes and characterize their CFL number as a function ofθ=d/h^(2)with d being the dispersion coefficient,which leads to several interesting observations.We also investigate the asymptotic behaviors of the CFL number for sufficiently refined meshes and derive the necessary conditions for the asymptotic stability of the IMEX-RK methods.Some numerical experiments are provided in the paper to illustrate the performance of IMEX methods under different time-step constraints.
基金supported by the National Natural Science Foundation of China(NSFC)under Grants 11825301,12003016,12073077the National Key R&D Program of China No.2021YFA0718600+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences with the Grant No.XDA15018400the Youth Innovation Promotion Association of CAS(2023061)。
文摘The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.
基金financially supported by the National Natural Science Foundation of China (no. 31272510)the Science Foundation of Xi'an (no. NC1405(1))the Innovation Fund of Graduate Student of Northwest University (no. YZZ13034)
文摘The amino acid contents of five floral sources Chinese honeys(jujube, rape, chaste, acacia, and lungan) were measured using reversed phase high-performance liquid chromatography(RP-HPLC). The results showed that proline was the main amino acid in most of the analyzed samples. Phenylalanine presents at the highest content in chaste honey samples, and the total amino acid contents of chaste honeys were also significantly higher than those of other honey samples. Based on the amino acid contents, honey samples were classified using chemometric methods(cluster analysis(CA), principal component analysis(PCA), and discriminant analysis(DA)). According to the CA results, chaste honeys could be separated from other honeys, while the remaining samples were correctly grouped together when the chaste honey data were excluded. By using DA, the overall correct classification rate reached 100%. The results revealed that amino acid contents could potentially be used as indicators to identify the botanical origin of unifloral honeys.
基金National Natural Science Foundation of China (Nos. 51573200, 11872132 and U183720015) for financial support
文摘Polymer nanocomposites have been investigated for about three decades. To get deep insights into the modifying effects of various nanofillers on mechanical and physical properties of polymer nanocomposites, the three basic aspects of processing, characterization and properties are critically reviewed in this paper. Nanofillers can be classified into three major types of two-dimensional (2D) layered, one-dimensional (1D) fibrous and zerodimensional (0D) spherical ones and this review thus discusses in detail the processing, characterization and properties of the three types of polymer nanocomposites. It starts with an introduction of various nanoscale fillers such as two-dimensional (2D) nano-clay, graphene and MXene, one dimensional (1D) carbon nanofibers and nanotubes, zero dimensional (0D) silica nanoparticles and ZnO quantum dots as well as nanofiller-polymer interfaces. The processing of these polymer nanocomposites using different methods and the characterization of nanofillers and polymer nanocomposites using various techniques are described. Finally, the mechanical and physical properties of these polymer nanocomposites are discussed by considering the effects of nanofiller type, dispersion and contents;also, interface properties show significant effects on the mechanical properties of polymer nanocomposites and are discussed in some details.
基金Projects(51764014,11902127)supported by the National Natural Science Foundation of ChinaProject(201810407004)supported by the National Undergraduate Innovation Training Program of ChinaProject(GJJ180457)supported by Jiangxi Education Department,China。
文摘The two-dimensional infiltration experiment was carried out by means of digital image technology.The evolution process of the wetting body was described.The wetted front distance and the time show a very significant power function relationship.The horizontal wetted distance is larger than the vertical wetted distance in the initial stage.Then,the vertical distance of the wetted body gradually approaches to the horizontal distance.The infiltration distance decreases as the content of fine particles increases.The wetted front migration rate curve shows a three-stage change law,and it increases with the increase of coarse particle content.The directional velocity ratio is defined.The initial value of horizontal infiltration rate is larger than that of vertical one,and then the vertical infiltration rate is gradually close to the horizontal value.The empirical relationship between the characteristic particle size and the stable infiltration rate is established,which provides a theoretical basis for the prediction of the stable infiltration rate in in-situ leaching.
基金supported by the National Natural Science Foundation of China(No.62172288)the Beijing Municipal Science&Technology Commission(Z151100003915095).
文摘BACKGROUND Remote ischemic conditioning(RIC)is used to protect against myocardial injury.However,there is no adequate evidence for comprehensive RIC in elderly patients with ST-segment elevation myocardial infarction(STEMI).This study aimed to test whether comprehensive RIC,started pre-primary percutaneous coronary intervention(PPCI)and repeated daily on 1-30 days post-PPCI,can improve myocardial salvage index(SI),left ventricular ejection fraction(LVEF),Kansas City Cardiomyopathy Questionnaire Clinical Summary Score(KCCQ-CSS)and 6-min walk test distance(6MWD)in elderly patients with acute STEMI during 12 months follow-up.METHODS 328 consenting elderly patients were randomized to receive standard PPCI plus comprehensive RIC(the treatment group)or standard PPCI(the control group).SI at 5-7 days after PPCI,LVEF,left ventricular end-diastolic volume index(LVEDVI),left ventricular end-systolic volume index(LVESVI),KCCQ-CSS,6MWD and adverse events rates were measured and assessed.RESULTS SI was significantly higher in the treatment group[interquartile range(IQR):0.38-0.66,P=0.037].There were no significant differences in major adverse events at 12 months.Although the differences of LVEDVI,LVESVI and LVEF between the treatment group and the control group did not reach statistical significance at 6 months and 12 months,LVEF tended to be higher,LVEDVI tended to be lower in the treatment group.The KCCQ-CSS was significantly higher in the treatment group at 1 month(IQR:46.5-87,P=0.001)and 12 months(IQR:55-93,P=0.008).There was significant difference in 6MWD between the treatment group and the control group(IQR:258-360 vs.IQR:250-345,P=0.002)at 1 month and(IQR:360-445 vs.IQR:345-432,P=0.035)at 12 months.A modest correlation was found between SI and LVEF(r=0.452,P<0.01),KCCQ-CSS(r=0.440,P<0.01)and 6MWD(r=0.384,P<0.01)respectively at 12 months.CONCLUSIONS The comprehensive RIC can improve SI,KCCQ-CSS and 6MWD.It may be an adjunctive therapy to PPCI in elderly patients with STEMI.
基金supported by the National Science and Technology Major Projects of China (No. 2016ZX05042 and No. 2017ZX05039)the National Natural Science Foundation Projects of China (No. 51504269 and No. 51490654)Science Foundation of China University of Petroleum, Beijing (No.C201605) to support part of this work。
文摘In this work,a flowing material balance equation(FMBE) is established for under saturated coalbed methane(CBM) reservoirs,which considers immobile free gas expansion effect at the dewatering stage.Based on the established FMBE,five straight-line methods are proposed to determine the control area,initial water reserve,initial free gas reserve,initial adsorbed gas reserve,original gas in place,as well as permeability at the same time.Subsequently,the proposed FMBE methods for undersaturated CBM reservoirs are validated against a reservoir simulation software with and without considering free gas expansion.Finally,the proposed methods are applied in a field case when considering free gas expansion effect.Validation cases show that the straight-line relationships for the proposed five FMBE methods are excellent,and good agreements are obtained among the actual reserves and permeabilities and those evaluated by the proposed five FMBE methods,indicating the proposed five FMBE methods are effective and rational for CBM reservoirs.Results show that a small amount of free gas will result in a great deviation in reserve evaluation;hence,the immobile free gas expansion effect should be considered when establishing the material balance equation of undersaturated CBM reservoirs at the dewatering stage.
基金supported by the National Natural Science Foundation of China (No.30770302 and 30570970)the Program of Ministry of Science and Technology of the Republic of China (No.2006FY110500)partially by the National Science Fund for Fostering Talents in Basic Research (NSFC-J0630964/J0109)
文摘Codon usage bias varies considerably among genomes and even within the genes of the same genome. In eukaryotic organisms, energy production in the form of oxidative phosphorylation (OXPHOS) is the only process under control of both nuclear and mitochondrial genomes. Although factors affecting codon usage in a single genome have been studied, this has not occurred when both interactional genomes are involved. Consequently, we investigated whether or not other factors influence codon usage of coevolved genes. We used Drosophila melanogaster as a model organism. Our χ^2 test on the number of codons of nuclear and mitochondrial genes involved in the OXPHOS system was significantly different (χ^2= 7945.16, P 〈 0.01). A plot of effective number of codons against GC3s content of nuclear genes showed that few genes lie on the expected curve, indicating that codon usage was random. Correspondence analysis indicated a significant correlation between axis 1 and codon adaptation index (R = 0.947, P 〈 0.01) in every nuclear gene sequence. Thus, codon usage bias of nuclear genes appeared to be affected by translational selection. Correlation between axis 1 coordinates and GC content (R = 0.814, P 〈 0.01) indicated that the codon usage of nuclear genes was also affected by GC composition. Analysis of mitochondrial genes did not reveal a significant correlation between axis 1 and any parameter. Statistical analyses indicated that codon usages of both nDNA and mtDNA were subjected to context-dependent mutations.
基金Supported by the Key Project of Scientific and Technological Research of Hebei Provincial University(ZD2015107)
文摘In the present work, the TIPS behavior of isotactic polypropylene(iP P)/di-n-butyl phthalate(DBP)/dioctyl phthalate(DOP)/nano-SiO_2 system and the competition relation between liquid–liquid phase separation and polymer crystallization are successfully adjusted by adding nano-SiO_2. The liquid–liquid phase separation temperature of the system increases with increasing nano-SiO_2 content. Besides, iP P crystallization temperature is also changed after adding nano-SiO_2. IPP/nano-SiO_2 blend hollow fiber microporous membrane is prepared via TIPS method. SEM photos show that the membrane exhibits mixed morphology combining cellular structure relating to liquid–liquid phase separation and branch structure originating from polymer crystallization. The relative weight of cellular structure first decreases and then increases with the increase of nano-SiO_2 content. Furthermore, porosity, connectivity among pores and pure water flux of the membrane first increase and then decrease with increasing nano-SiO_2 content. However, mechanical performance of the membrane is improved at all times with increasing nano-SiO_2 content.
基金supported by the financial support of the ship segmentation intelligent manufacturing equipment solution and key common technology research,High-tech Ship Research Project of the Chinese Ministry of Science and Technology and the project of Shandong Provincial Key R&D Program(No.2019GGX104035).
文摘Path planning is a key technique of autonomous navigation for robots,and the velocity field is an important part.Constructing velocity field in a complex workspace is still challenging.In this paper,an inner normal guided segmentation algorithm in a complex polygon is proposed to decompose the complex workspace in this paper.The artificial potential field model based on probability theory is then used to calculate the potential field of the decomposed workspace,and the velocity field is obtained by utilizing the potential field of this workspace.Path optimization is implemented by curve evolution,during which the internal force generated in the smoothing process of the initial path by a mean filter and the external force is obtained from the gradient of the workspace potential field.The parameter selection principle is deduced by analyzing the influence of several parameters on the path length and smoothness.Simulation results show that the designed polygon decomposition algorithm can effectively segment complex workspace and that the path optimization algorithm can shorten and smoothen paths.
基金the National Natural Science Foundation of China under Grant Nos 11874431 and 11804181the National Key R&D Program of China under Grant No 2018YFA0306800+1 种基金the Guangdong Science and Technology Innovation Youth Talent Program under Grant Nos 2016TQ03X688 and 2018YFA0306504the Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics under Grant No ZZ201803.
文摘Advanced machine learning(ML)approaches such as transfer learning have seldom been applied to approximate quantum many-body systems.Here we demonstrate that a simple recurrent unit(SRU)based efficient and transferable sequence learning framework is capable of learning and accurately predicting the time evolution of the one-dimensional(ID)Ising model with simultaneous transverse and parallel magnetic fields,as quantitatively corroborated by relative entropy measurements between the predicted and exact state distributions.At a cost of constant computational complexity,a larger many-body state evolution is predicted in an autoregressive way from just one initial state,without any guidance or knowledge of any Hamiltonian.Our work paves the way for future applications of advanced ML methods in quantum many-body dynamics with knowledge only from a smaller system.
基金supported by NSF Grants DMS-1719410 and DMS-2010107by AFOSR Grant FA9550-20-1-0055.
文摘A time discretization method is called strongly stable(or monotone),if the norm of its numerical solution is nonincreasing.Although this property is desirable in various of contexts,many explicit Runge-Kutta(RK)methods may fail to preserve it.In this paper,we enforce strong stability by modifying the method with superviscosity,which is a numerical technique commonly used in spectral methods.Our main focus is on strong stability under the inner-product norm for linear problems with possibly non-normal operators.We propose two approaches for stabilization:the modified method and the filtering method.The modified method is achieved by modifying the semi-negative operator with a high order superviscosity term;the filtering method is to post-process the solution by solving a diffusive or dispersive problem with small superviscosity.For linear problems,most explicit RK methods can be stabilized with either approach without accuracy degeneration.Furthermore,we prove a sharp bound(up to an equal sign)on diffusive superviscosity for ensuring strong stability.For nonlinear problems,a filtering method is investigated.Numerical examples with linear non-normal ordinary differential equation systems and for discontinuous Galerkin approximations of conservation laws are performed to validate our analysis and to test the performance.
文摘This paper presents a combination method of Particle Swarm Optimization (PSO) and topology optimization. With this method a better result can be achieved compared with the sequential application of these two optimization methods. It inherits the ability in finding global optimum from PSO and also suits for discretized design domain. Some special schemes are used in order to provide higher computation efficiency. This method has only been tested with a convex optimization problem. The application in case of a concave problem will be a future study.
文摘Objective:The aim of this study was to investigate the potential ability of medicated serum of Erzhi pills on growth,proliferation and inflammation of the human breast cancer cell line MCF-7 cells.Methods:3-month-old female Sprague–Dawley rats were used to prepared medicated serum,and randomly assigned into four groups:control group(distillated water),low doses(2.25g/kg/d),middle doses(4.5g/kg/d),high does(9.0g/kg/d).The growth curve was meas-ured by MTT method,the proliferation was examined by colony formation assay.Inflam-matory cytokines IL-1β,IL-18 and IL-6 was detected by Quantitative real time polymerase chain reaction(RT-qPCR).Western blot was used to examine the expression of NF-kB signal pathway.Results:The medicated serum of Erzhi pills could inhibit the growth and proliferation of breast cancer cell MCF-7,especially,in the group of middle doses and high does(P<0.05).The protein expression of IKKα,IκBαand p-NF-κB were significantly down regulated.As well as the mRNA expression levels of Inflammatory cytokine,such as IL-1β,IL-18 and IL-6,were decreased.Conclusion:Medicated serum of Erzhi pills played an anti-tumor role in breast cancer via inhibiting the growth and proliferation of MCF-7.Moreover,Erzhi pills could suppress in-flammatory responses from the NFκB signaling pathways,and reduced skeletal muscle pain caused by breast cancer endocrine therapy,and Erzhi pills may be a new target for the treatment of breast cancer.
文摘Objective:To explore the diagnostic value of traditional Chinese medical(TCM)dialectical classification in Hashimoto's thyroiditis complicated with suspicious nodules.Methods:The clinical data of patients with Hashimoto's thyroiditis complicated with thyroid nodules in the Department of Breast and thyroid surgery of Weifang Hospital of traditional Chinese Medicine from January 2018 to December 2019 were collected.The patients were examined by 2 or more experienced TCM doctors,and the four diagnostic data were obtained,and then the relevant syndrome types of the patients were judged according to the data.According to the color Doppler ultrasonographic features of thyroid nodules,the patients who met the indication of fine needle aspiration biopsy of thyroid nodules were selected and underwent fine needle aspiration biopsy of thyroid nodules before operation.To analyze the clinical diagnostic value of that the ultrasonic mode used in this study and thyroid cytopathology Bethesda report system combine dialectical classification of traditional Chinese medicine in Hashimoto's thyroiditis complicated with suspected thyroid nodules.Result:A total of 89 patients with Hashimoto's thyroiditis complicated with thyroid nodules were collected.according to the ultrasonic mode,the difference between different modes was statistically significant(P<0.05).The mode of color ultrasound is also related to the dialectical classification of traditional Chinese medicine.The patients with high malignant risk score are mainly qi depression and phlegm stagnation,phlegm and blood stasis,while those with low score are exuberant liver fire and heart liver yin deficiency.According to the study of different The Bethesda System for Reporting Thyroid Cytopathology(TBSRTC)classification,the dialectical classification of patients with higher TBSRTC classification was more inclined to qi depression and phlegm stagnation,phlegm and blood stasis,and there was significant difference between different classification(P<0.05).Conclusion:Qi depression and phlegm obstruction,phlegm and blood stasis have high ultrasound malignant risk score and high TBSRTC classification grade in patients with Hashimoto's thyroiditis complicated with suspected thyroid nodules,which has important clinical diagnostic value.