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Chinese Journal of Aeronautics 2024年第3期37卷 34-48页

作者： Fanzhi ZENG Tianxin ZHANG Denggao TANG Jinping LI chao yan School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China School of Aeronautical Engineering Air Force Engineering UniversityXi’an 710038China

Accurate prediction of Shock-Wave/Boundary Layer Interaction(SWBLI)flows has been a persistent challenge for linear eddy viscosity models.A major limitation lies in the isotropic representation of the Reynolds stress,as assumed under the Boussinesq *** studies have shown promise in improving the prediction capability for incompressible separation flows by perturbing the Reynolds-stress anisotropy ***,it remains uncertain whether this approach is effective for SWBLI flows,which involve compressibility and *** address this issue,this study systematically quantifies the structural uncertainty of the anisotropy for oblique SWBLI *** eigenspace perturbation method is applied to perturb the anisotropy tensor predicted by the Menter Shear–Stress Transport(SST)model and reveal the impacts of anisotropy on the prediction of quantities of interest,such as separation and reattachment positions,wall static pressure,skin friction,and heat *** results demonstrate the potential and reveal the challenges of eigenspace perturbation in improving the SST ***,a detailed analysis of turbulent characteristics is performed to identify the source of *** findings indicate that eigenspace perturbation primarily affects turbulent shear stress,while the prediction error of the SST model is more related to turbulent kinetic energy.

关键词： Shock-wave/boundary layer interaction(SWBLI) Turbulence models Uncertainty analysis Eigenspace perturbation Anisotropy

A Hybrid Air Quality Prediction Model Based on Empirical Mode Decomposition

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Tsinghua Science and Technology 2024年第1期29卷 99-111页

作者： Yuxuan Cao Difei Zhang Shaoqi Ding Weiyi Zhong chao yan School of Computer Science Qufu Normal UniversityRizhao 276826China School of Mathematical Sciences Qufu Normal UniversityQufu 273165China School of Computer Science Qufu Normal UniversityRizhao 270826China College of Economic and Management Shandong University of Science and TechnologyQingdao 250307China

Air pollution is a severe environmental problem in urban *** air quality prediction can help governments and individuals make proper decisions to cope with potential air *** a classic time series forecasting model,the AutoRegressive Integrated Moving Average(ARIMA)has been widely adopted in air quality ***,because of the volatility of air quality and the lack of additional context information,i.e.,the spatial relationships among monitor stations,traditional ARIMA models suffer from unstable prediction *** some deep networks can achieve higher accuracy,a mass of training data,heavy computing,and time cost are *** this paper,we propose a hybrid model to simultaneously predict seven air pollution indicators from multiple monitoring *** proposed model consists of three components:(1)an extended ARIMA to predict matrix series of multiple air quality indicators from several adjacent monitoring stations;(2)the Empirical Mode Decomposition(EMD)to decompose the air quality time series data into multiple smooth sub-series;and(3)the truncated Singular Value Decomposition(SvD)to compress and denoise the expanded *** results on the public dataset show that our proposed model outperforms the state-of-art air quality forecasting models in both accuracy and time cost.

关键词： air quality prediction Empirical Mode Decomposition(EMD) Singular Value Decomposition(SVD) AutoRegressive Integrated Moving Average(ARIMA)

Central environmental protection inspection and carbon emission reduction: A tripartite evolutionary game model from the perspective of carbon neutrality

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Petroleum Science 2024年第3期21卷 2139-2153页

作者： Zhen-Hua Zhang Dan Ling Qin-Xin yang yan-chao Feng Jing Xiu School of Economics Lanzhou UniversityLanzhou 730000GansuChina Institute of Green Finance Lanzhou UniversityLanzhou 730000GansuChina School of Management Lanzhou UniversityLanzhou 730000GansuChina School of Business Zhengzhou UniversityZhengzhou 450001HenanChina Institute of Economics Jilin Academy of Social SciencesChangchun130033JilinChina

Since the carbon neutrality target was proposed,many countries have been facing severe challenges to carbon emission reduction *** study is conducted using a tripartite evolutionary game model to explore the impact of the central environmental protection inspection(CEPI)on driving carbon emission reduction,and to study what factors influence the strategic choices of each party and how they interact with each *** research results suggest that local governments and manufacturing enterprises would choose strategies that are beneficial to carbon reduction when CEPI *** the initial willingness of all parties increases 20%,50%—80%,the time spent for the whole system to achieve stability decreases from 100%,60%—30%.The evolutionary result of“thorough inspection,regulation implementation,low-carbon management”is the best strategy for the tripartite evolutionary ***,the smaller the cost and the larger the benefit,the greater the likelihood of the three-party game stability strategy *** study has important guiding significance for other developing countries to promote carbon emission reduction by environmental policy.

关键词： Central environmental protection inspection Local government Manufacturing enterprise Tripartite evolutionary game Carbon emission reduction

Synergistically constructed lamination-like network of redox-active polyimide and MXene via π-π interactions for aqueous NH_(4)^(+) storage

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Chinese Journal of Chemical Engineering 2024年第7期71卷 217-224页

作者： Jing He Hongye Xuan Jing Jin Ke Yu Changyao Liyang Lintong Hu Minjie Shi chao yan School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Jiangsu New yangzi Shipbuilding Co. LtdJingjiang 214532China

As a nonmetallic charge carrier,ammonium ion(NH_(4)^(+))has garnered significant attention in the construction of aqueous batteries due to its advantages of low molar mass,small hydration size and rapid diffusion in aqueous *** are a kind of potential electro-active materials for aqueous NH_(4)^(+)***,traditional polymer electrodes are typically created by covering the bulky collectors with excessive additives,which could lead to low volume capacity and unsatisfactory ***,a nanoparticle-like polyimide(PI)was synthesized and then combined with MXene nanosheets to synergistically construct an additive-free and self-standing PI@MXene composite ***,the redox-active PI nanoparticles are enclosed between conductive MXene flakes to create a 3D lamination-like network that promotes electron transmission,while theπ-πinteractions existing between PI and MXene contribute to the enhanced structural integrity and stability within the composite *** such,it delivers superior aqueous NH_(4)^(+)storage behaviors in terms of a notable specific capacity of 110.7 mA·h·cm^(–3) and a long lifespan with only 0.0064%drop each ***,in-situ Raman and UV–Vis examinations provide evidence of reversible and stable redox mechanism of the PI@MXene composite electrode during NH_(4)^(+)uptake/removal,highlighting its significance in the area of electrochemical energy storage.

关键词： Synergetic coupling Composite materials Polyimide Energy storage Aqueous ammonium ion batteries

Associations of serum D-dimer and glycosylated hemoglobin levels with third-trimester fetal growth restriction in gestational diabetes mellitus

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World Journal of Diabetes 2024年第5期15卷 914-922页

作者： Ying Zhang Teng Li chao-yan Yue Yun Liu Department of Laboratory Medicine Obstetrics and Gynecology Hospital of Fudan UniversityShanghai 200011China Department of Interventional Radiology The People’s Hospital of Weifang CityWeifang 261041Shandong ProvinceChina Department of Hematology The People’s Hospital of Weifang CityWeifang 261041Shandong ProvinceChina

BACKGROUND Gestational diabetes mellitus(GDM)is a special type of diabetes that commonly occurs in women during pregnancy and involves impaired glucose tolerance and abnormal glucose metabolism;GDM is diagnosed for the first time during pregnancy and can affect fetal growth and *** To investigate the associations of serum D-dimer(D-D)and glycosylated hemoglobin(HbA1c)levels with third-trimester fetal growth restriction(FGR)in GDM *** The clinical data of 164 pregnant women who were diagnosed with GDM and delivered at the Obstetrics and Gynecology Hospital of Fudan University from January 2021 to January 2023 were analyzed *** these women,63 whose fetuses had FGR were included in the FGR group,and 101 women whose fetuses had normal body weights were included in the normal body weight group(normal group).Fasting venous blood samples were collected from the elbow at 28-30 wk gestation and 1-3 d before delivery to measure serum D-D and HbA1c levels for comparative *** diagnostic value of serum D-D and HbA1c levels for FGR was evaluated by receiver operating characteristic analysis,and the influencing factors of third-trimester FGR in GDM patients were analyzed by logistic *** Serum fasting blood glucose,fasting insulin,D-D and HbA1c levels were significantly greater in the FGR group than in the normal group,while the homeostasis model assessment of insulin resistance values were lower(P<0.05).Regarding the diagnosis of FGR based on serum D-D and HbA1c levels,the areas under the curves(AUCs)were 0.826 and 0.848,the cutoff values were 3.04 mg/L and 5.80%,the sensitivities were 81.0%and 79.4%,and the specificities were 88.1%and 87.1%,*** AUC of serum D-D plus HbA1c levels for diagnosing FGR was 0.928,and the sensitivity and specificity were 84.1%and 91.1%,*** D-D and HbA1c levels were risk factors for third-trimester FGR in GDM patients(P<0.05).CONCLUSION D-D and HbA1c levels can

关键词： Gestational diabetes mellitus D-dimer Hemoglobin Fetal growth restriction Fasting blood glucose

Understanding the spatial interaction of ultrasounds based on three-dimensional dual-frequency ultrasonic field numerical simulation

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China Foundry 2024年第1期21卷 29-43页

作者： Zhao-yang Yin Qi-chi Le yan-chao Jiang Da-zhi Zhao Qi-yu Liao Qi Zou Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

A transient 3D model was established to investigate the effect of spatial interaction of ultrasounds on the dual-frequency ultrasonic field in magnesium alloy *** effects of insertion depth and tip shape of the ultrasonic rods,input pressures and their ratio on the acoustic field distribution were discussed in ***,the spacing,angle,and insertion depth of two ultrasonic rods significantly affect the interaction between distinct *** a result,various acoustic pressure distributions and cavitation regions are *** spherical rods mitigate the longitudinal and transversal attenuation of acoustic pressure and expand the cavitation volume by 53.7%and 31.7%,respectively,compared to the plate and conical *** the input pressure will enlarge the cavitation region but has no effect on the acoustic pressure distribution *** acoustic pressure ratio significantly affects the pressure distribution and the cavitation region,and the best cavitation effect is obtained at the ratio of 2:1(P15:P20).

关键词： dual-frequency ultrasonic numerical model acoustic pressure spatial interaction magnesium alloy

Current status of Mycoplasma pneumoniae infection in China

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World Journal of Pediatrics 2024年第1期20卷 1-4页

作者： chao yan Guan-Hua Xue Han-Qing Zhao yan-Ling Feng Jing-Hua Cui Jing Yuan Department of Bacteriology Capital Institute of PediatricsNo.2Yabao RoadBeijing 100020People's Republicof China

Mycoplasma pneumoniae(***)is one of the most important pathogens for community-acquired pneumonia worldwide,especially in children and adolescents[1,2].*** is easily transmitted through droplets or direct contact in densely populated,enclosed,or poorly ventilated *** incubation period is 1-3 weeks,and it is contagious from the incubation period to a few weeks after clinical symptom *** infection can occur in any season,and there are differences in the epidemic seasons among regions in China[3].The most suitable culture temperature for *** is between 35℃C and 37 C,and therefore,hot weather may make it survive longer in the environment and spread *** is more common in autumn and winter in northern China,while it is more prevalent in summer and autumn in southern China.

关键词： winter weather autumn

Effects of Lactobacillus paracasei N1115 on gut microbial imbalance and liver function in patients with hepatitis B-related cirrhosis

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World Journal of Gastroenterology 2024年第11期30卷 1556-1571页

作者： yan-chao Hu Xiang-Chun Ding Hui-Juan Liu Wan-Long Ma Xue-yan Feng Li-Na Ma Department of Infectious Disease General Hospital of Ningxia Medical UniversityYinchuan 750004Ningxia Hui Autonomous RegionChina Infectious Disease Clinical Research Center of Ningxia Yinchuan 750004Ningxia Hui Autonomous RegionChina

BACKGROUND Hepatitis B cirrhosis(HBC)is a chronic disease characterized by irreversible diffuse liver damage and aggravated by intestinal microbial imbalance and metabolic *** the relationship between certain single probiotics and HBC has been explored,the impact of the complex ready-to-eat Lactobacillus paracasei N1115(LP N1115)supplement on patients with HBC has not been *** To compare the changes in the microbiota,inflammatory factor levels,and liver function before and after probiotic treatment in HBC *** This study included 160 HBC patients diagnosed at the General Hospital of Ningxia Medical University between October 2018 and December *** were randomly divided into an intervention group that received LP N1115 supplementation and routine treatment and a control group that received routine treatment *** samples were collected at the onset and conclusion of the 12-wk intervention *** structure of the intestinal microbiota and the levels of serological indicators,such as liver function and inflammatory factors,were *** Following LP N1115 intervention,the intestinal microbial diversity significantly increased in the intervention group(P<0.05),and the structure of the intestinal microbiota was characterized by an increase in the proportions of probiotic microbes and a reduction in harmful ***,the intervention group demonstrated notable improvements in liver function indices and significantly lower levels of inflammatory factors(P<0.05).CONCLUSION LP N1115 is a promising treatment for ameliorating intestinal microbial imbalance in HBC patients by modulating the structure of the intestinal microbiota,improving liver function,and reducing inflammatory factor levels.

关键词： Hepatitis B cirrhosis N1115 ready-to-eat lactobacillus Inflammation Liver function Lachnospiraceae incertae sedis Probiotic

The Continuity of Head Nouns:The Difference in Relativizability between Korean and Chinese

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Journal of Foreign Languages and Cultures 2024年第1期8卷 122-138页

作者： chao yan Hunan Normal University

The Noun Phrase Accessibility Hierarchy cannot explain the difference in relativizability between Chinese and Korean in authentic *** exhibits a higher preference for relativization compared to Chinese and this article aims to account for this difference from the perspective of topic ***,the continuity of head nouns within relative clauses is stronger in Korean than in *** analyzing the parameters of referential distance and potential interference,this study finds that the head nouns in Korean relative clauses display a broader range on the continuum of continuity compared to those in Chinese relative ***,the difference in the strength of continuity of head nouns between Chinese and Korean relative clauses is attributed to the typological distinction between the Component-Integral Languages and Component-Metonymic Languages postulated within the framework of the Event-Domain Cognitive Model.

关键词： relative clauses head nouns topics continuity component-Integral languages component-metonymic languages

Effect of Artificial Cooling Extrusion on Microstructure and Mechanical Properties of Mg–Zn–Y Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1115-1127页

作者： Qi-Yu Liao Da-Zhi Zhao Qi-Chi Le Wen-Xin Hu yan-chao Jiang Wei-yang Zhou Liang Ren Dan-Dan Li Zhao-yang Yin School of Materials Science and Engineering Northeastern UniversityShenyang110819China Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang110819China Key Laboratory of Lightweight Structural Materials Liaoning ProvinceNortheastern UniversityShenyang110819China Baotou Research Institute of Rare Earths Baotou014000China

Microstructure and mechanical properties of Mg–Zn–Y alloys with different Zn/Y atomic ratios with or without artificial cooling (AC) extrusion were systematically investigated in this work. The results show that bimodal microstructure consisting of submicron dynamic recrystallized (DRXed) grains with high fraction of low-angle grain boundaries (LAGBs) and elongated unDRXed grains was formed in Mg_(98.7)Zn_(1)Y_(0.3) alloy with AC extrusion. The AC process effectively limits the growth of precipitated phases, and large amount of nanoscale precipitates were dynamically precipitated during the extrusion process. AC extrusion could effectually refine the lamellar 14H LPSO phases and inhibit the transition from stacking faults to LSPO phases in Mg_(98)Zn_(1)Y_(1) alloy and the narrow LPSO phase in Mg_(98)Zn_(1)Y_(1)-AC alloy which could promote the nucleation of DRXed grains. The AC extrusion significantly improves the strength of Mg–Zn–Y alloys. Owing to AC extrusion, the strength improvement of Mg_(98.7)Zn_(1)Y_(0.3) alloy is mainly attributed to fine grain strengthening, dislocation strengthening, and nano-phases precipitation strengthening. After AC process, more fine grains and nano-phases jointly strengthen the Mg_(98)Zn_(1)Y_(1) alloy. The Mg_(98)Zn_(1)Y_(1) alloy obtains optimal mechanical properties after extrusion at 623 K, with ultimate tensile strength (UTS) of 406 MPa, yield strength (YS) of 388 MPa, and elongation (EL) of 5.6%.

关键词： Mg-Zn-Y Artificial cooling Extrusion Microstructure Mechanical properties