Multi-scale Modeling and Finite Element Analyses of Thermal Conductivity of 3D C/SiC Composites Fabricating by Flexible-Oriented Woven Process

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.

Stability and Time-Step Constraints of Implicit-Explicit Runge-Kutta Methods for the Linearized Korteweg-de Vries Equation

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.

The Solar Upper Transition Region Imager(SUTRI)Onboard the SATech-01 Satellite

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.

Identification of botanical origin of Chinese unifloral honeys by free amino acid profiles and chemometric methods

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.

Some basic aspects of polymer nanocomposites: A critical review

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.

Efficacy of comprehensive remote ischemic conditioning in elderly patients with acute ST-segment elevation myocardial infarction underwent primary percutaneous coronary intervention

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.

Methods for simultaneously evaluating reserve and permeability of undersaturated coalbed methane reservoirs using production data during the dewatering stage

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.

旋流器结构参数对燃烧室燃烧性能影响的数值分析

采用数值分析方法研究旋流器结构特征参数对中心分级燃烧室燃烧性能的影响规律,从回流区特性、燃烧室温度场、出口温度特性、NOx排放等几个方面分析了燃烧室燃烧性能。研究结果表明:旋流器值班级第一、第二级以及主燃级叶片安装角和旋向对燃烧室燃烧性能有着重要影响;最佳叶片角度方案为值班级第一级叶片45°、第二级叶片45°、主燃级叶片安装角60°;最优旋向组合为值班级第一级叶片与第二级叶片反向,第二级叶片与主燃级叶片同向。

胰升血糖素样肽1对新诊断糖尿病患者分泌型卷曲相关蛋白1和β-连环蛋白表达水平的影响

目的观察新诊断糖尿病患者经胰升血糖素样肽1(GLP-1)治疗后分泌型卷曲相关蛋白1(SFRP1)和β-连环蛋白(β-catenin)表达水平的变化。方法选取2015年1~12月于该院内分泌门诊就诊或病房住院治疗的新诊断T2DM患者(T2DM组)72例和同期体检健康者(NC组)80例,收集两组入组时的临床资料和生化指标并比较。采用酶联吸附免疫法(ELISA)检测两组入组时、T2DM组经利拉鲁肽治疗12周和停药12周后的SFRP1和β-catenin的水平变化。结果 (1)T2DM组BMI、FPG、Fins、Hb A1c、HOMAIR、SFRP1及β-catenin均高于NC组,HOMA-β低于NC组;(2)与入组时比较,T2DM组治疗12周和停药12周时BMI、FPG、Hb A1c、TC、HDL-C、HOMA-IR均降低,HOMA-β升高;(3)T2DM组不同时间SFRP1和β-catenin水平比较,差异有统计学意义(F=120.633和376.649,均P=0.000),利拉鲁肽治疗12周时和停药12周时SFRP1均高于入组时(t=-9.294和-9.927,均P=0.000),β-catenin低于入组时(t=18.468和6.956,均P=0.000),且停药12周时SFRP1低于治疗12周时(t=6.355,P=0.000),β-catenin水平高于治疗12周时(t=18.129,P=0.000)。结论 GLP-1治疗新诊断T2DM患者可改善胰岛β细胞功能改善,升高SFRP1水平,降低β-catenin的水平,其原因可能与影响Wnt信号通路有关。

Factors affecting mito-nuclear codon usage interactions in the OXPHOS system of Drosophila melanogaster

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.

旋流器值班级叶片安装角对燃烧室燃烧性能的影响

常压下试验研究了中心分级燃烧室旋流器值班级叶片安装角对燃烧室燃烧性能的影响。结果表明:当值班级第1、第2级叶片安装角从30°增加至60°时,贫油熄火油气比均呈现减小趋势,燃烧室贫油熄火特性变好;随着油气比的增加,各方案燃烧火焰特性变好,CO排放、出口温度、燃烧效率均增加,A方案燃烧性能最佳。综合得出叶片安装角存在合理值,即值班级第1、第2级叶片安装角应在45°至60°之间,且值班级第2级叶片安装角变化对燃烧性能的影响较第1级叶片安装角变化的要强。

TIPS behavior for IPP/nano-SiO_2 blend membrane formation and its contribution to membrane morphology and performance

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.

An eikonal equation based path planning method using polygon decomposition and curve evolution

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.

Predicting Quantum Many-Body Dynamics with Transferable Neural Net works

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.

Enforcing Strong Stability of Explicit Runge-Kutta Methods with Superviscosity

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.

Efficient Combination of Topology and Parameter Optimization

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.

The anti-tumor effect of Erzhi pills on breast cancer cell MCF-7 and the intervention in endocrine therapy adverse reactions

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.

Diagnostic value of traditional Chinese medical dialectical classification in hashimoto's thyroiditis complicated with suspicious nodules

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.

makeTwin:A reference architecture for digital twin software platform

Digital twin is currently undergoing a significant transformation from the conceptual and theoretical research phase to the implementation and application phase.However,a universally adaptable research and development platform for digital twin is critically needed to meet the development requirements.Specifically,a publicly accessible simulation,testing,and validation platform which can support digital twin model building,data processing,algorithm design,configuration,etc.,is urgently required for researchers.Furthermore,for developers from the industry,a lowcode development platform that can offer a customizable suite of functions such as model creation,data management,protocol configuration,and visualization is urgently needed.Meanwhile,for enterprise users,there is a lack of an application management platform that can be configured and migrated for various application scenarios,functions,and modes.Therefore,based on the system research of digital twin theories and key technologies by the authors(such as the five-dimension digital twin model,digital twin modeling and digital twin data theory,digital twin standards,and so on),a digital twin software platform reference architecture,namely make Twin,is proposed and designed,as well as its ten core functions.The workflow of the make Twin and the interaction mechanisms among its core functions are described.Finally,a digital twin application system for a chemical fiber textile shop floor(CFTS)which was developed according to make Twin,is introduced,which validates the proposed reference architecture.

Observation of transition from superfluorescence to polariton condensation in CsPbBr3 quantum dots film

The superfluorescence effect has received extensive attention due to the many-body physics of quantum correlation in dipole gas and the optical applications of ultrafast bright radiation field based on the cooperative quantum state.Here,we demonstrate not only to observe the superfluorescence effect but also to control the cooperative state of the excitons ensemble by externally applying a regulatory dimension of coupling light fields.A new quasi-particle called cooperative exciton-polariton is revealed in a light-matter hybrid structure of a perovskite quantum dot thin film spin-coated on a Distributed Bragg Reflector.Above the nonlinear threshold,polaritonic condensation occurs at a nonzero momentum state on the lower polariton branch owning to the vital role of the synchronized excitons.The phase transition from superfluorescence to polariton condensation exhibits typical signatures of a decrease of the linewidth,an increase of the macroscopic coherence as well as an accelerated radiation decay rate.These findings are promising for opening new potential applications for super-brightness and unconventional coherent light sources and could enable the exploitation of cooperative effects for quantum optics.