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Distribution of oxide inclusions in H13 castings under super-gravity field with multi-stage rotation speeds

Journal of Iron and Steel Research(International) 2024年第1期31卷 121-133页

作者： Shao-ying Li Xiao-jun Xi xing-ming zhao Han-jie Guo Jing Guo School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China Beijing Beiye Functional Materials Corporation Beijing100192China Shandong Tianwu Forming Technology Co. Ltd.Liaocheng252024ShandongChina

The 42 kg industrial H13 castings were prepared by different super-gravity fields with multi-rotation speeds,and the distribution of oxide inclusions in the castings was *** addition,the inward movement Reynolds number and inward movement time of oxide inclusions as well as the solidification time of molten steel at different positions in the castings were calculated to clarify the removal mechanism of oxide inclusions in super-gravity *** results show that the large size(i.e.,greater than 10μm)oxide inclusions are mainly concentrated in the inner and outer parts of the super-gravity castings with constant rotation speed(500 r min^(-1))and five-stage rotation speeds(500,600,750,850,and 950 r min^(-1)),respectively,while there are no large oxide inclusions in the super-gravity castings with three-stage rotation speeds(500,600,and 750 r min^(-1)).Although an increase in the particle size of inclusion and the rotation speed in super-gravity field is conducive to the increase in the inward movement Reynolds number of oxide inclusions and reduction in the inward movement time of oxide inclusions,it will reduce the local solidification time of molten *** the range of the rotation speed studied,the super-gravity field with three-stage rotation speeds has the best effect on the removal of inclusions in H13 molten steel.

关键词： Distribution Oxide inclusion H13 casting Super-gravity field Rotation speed

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Relationship of Retinal Nerve Fiber Layer Thickness and Retinal Vessel Calibers with Cognitive Impairment in the Asymptomatic Polyvascular Abnormalities Population

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Biomedical and Environmental Sciences 2024年第2期37卷 196-203页

作者： WANG Dan Dan WANG An Xin ZHANG Xiao Li WEI Wen Bin WU Shou Ling zhao xing Quan Department of Neurology Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China China National Clinical Research Center for Neurological Diseases Beijing 100070China Beijing Tongren Eye Center Beijing Key Laboratory of Ophthalmology and Visual ScienceBeijing Tongren HospitalCapital Medical UniversityBeijing 100005China Department of Cardiology Kailuan HospitalTangshan 063001HebeiChina

Objective Cognitive impairment(CI)in older individuals has a high morbidity rate worldwide,with poor diagnostic methods and susceptible population *** study aimed to investigate the relationship between different retinal metrics and CI in a particular population,emphasizing polyvascular *** We collected information from the Asymptomatic Polyvascular Abnormalities Community Study on retinal vessel calibers,retinal nerve fiber layer(RNFL)thickness,and cognitive function of 3,785participants,aged 40 years or *** regression was used to analyze the relationship between retinal metrics and cognitive *** stratified by different vascular statuses were also *** RNFL thickness was significantly thinner in the CI group(odds ratio:0.973,95%confidence interval:0.953–0.994).In the subgroup analysis,the difference still existed in the non-intracranial arterial stenosis,non-extracranial carotid arterial stenosis,and peripheral arterial disease subgroups(P<0.05).Conclusion A thin RNFL is associated with CI,especially in people with non-large vessel *** underlying small vessel change in RNFL and CI should be investigated in the future.

关键词： Retinal nerve fiber layer Cognitive impairment Polyvascular abnormality

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Influencing factors analysis of hard limestone reformation and strength weakening under acidic effect

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Journal of Central South University 2024年第7期31卷 2446-2466页

作者： HOU Ming-xiao HUANG Bing-xiang zhao xing-long JIAO Xue-jie ZHENG Chen-yang State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and TechnologyXuzhou 221116China

Roof disaster has always been an important factor restricting coal mine safety *** effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way to control the hard limestone *** this study,the effects of various factors on the reaction characteristics and mechanical properties of limestone were *** results show that the acid with stronger hydrogen production capacity after ionization(pK_(a)<0)has more prominent damage to the mineral grains of *** pKa increases from−8.00 to 15.70,uniaxial compressive strength and elastic modulus of limestone increase by 117.22%and 75.98%.The influence of acid concentration is manifested in the dissolution behavior of mineral crystals,the crystal defects caused by large-scale acid action will lead to the deterioration of limestone strength,and the strength after 15%concentration reformation can be reduced by 59.42%.The effect of acidification time on limestone has stages and is the most obvious in the initial metathesis reaction stage(within 60 min).The key to the strength damage of acidified limestone is the participation of hydrogen ions in the reaction *** on the analytic hierarchy process method,the influence weights of acid type,acid concentration and acidification time on strength are 24.30%,59.54% and 16.16%,*** research results provide theoretical support for the acidification control of hard limestone roofs in coal mines.

关键词： hard roof acidic effect structural reformation strength weakening influencing factors

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Comparative study of different machine learning models in landslide susceptibility assessment: A case study of Conghua District, Guangzhou, China

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China Geology 2024年第1期7卷 104-115页

作者： Ao Zhang Xin-wen zhao xing-yuezi zhao Xiao-zhan Zheng Min Zeng Xuan Huang Pan Wu Tuo Jiang Shi-chang Wang Jun He Yi-yong Li Wuhan Center China Geological SurveyMinistry of Natural Resources(Geosciences Innovation Center of Central South China)Wuhan 430205China Guangzhou Institute of Geological Survey Guangzhou 510080China Hubei Transportation Planning Design Institute Co. LtdWuhan 430050China

Machine learning is currently one of the research hotspots in the field of landslide *** clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,Conghua District,which is the most prone to landslide disasters in Guangzhou,was selected for landslide susceptibility *** evaluation factors were selected by using correlation analysis and variance expansion factor *** four machine learning methods namely Logistic Regression(LR),Random Forest(RF),Support Vector Machines(SVM),and Extreme Gradient Boosting(XGB),landslide models were *** analysis and evaluation of the model were conducted through statistical indices and receiver operating characteristic(ROC)*** results showed that LR,RF,SVM,and XGB models have good predictive performance for landslide susceptibility,with the area under curve(AUC)values of 0.752,0.965,0.996,and 0.998,*** model had the highest predictive ability,followed by RF model,SVM model,and LR *** frequency ratio(FR)accuracy of LR,RF,SVM,and XGB models was 0.775,0.842,0.759,and 0.822,*** and XGB models were superior to LR and SVM models,indicating that the integrated algorithm has better predictive ability than a single classification algorithm in regional landslide classification problems.

关键词： Landslides susceptibility assessment Machine learning Logistic Regression Random Forest Support Vector Machines XGBoost Assessment model Geological disaster investigation and prevention engineering

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Nomogram prediction of vessels encapsulating tumor clusters in small hepatocellular carcinoma≤3 cm based on enhanced magnetic resonance imaging

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 1808-1820页

作者： Hui-Lin Chen Rui-Lin He Meng-Ting Gu xing-Yu zhao Kai-Rong Song Wen-Jie Zou Ning-Yang Jia Wan-Min Liu School of Health Science and Engineering University of Shanghai for Science and TechnologyShanghai 200093China Department of Radiology The Third Affiliated Hospital of Shanghai Naval Military Medical UniversityShanghai 200438China Department of Radiology Tongji University Affiliated Tongji HospitalShanghai 200065China

BACKGROUND Vessels encapsulating tumor clusters(VETC)represent a recently discovered vascular pattern associated with novel metastasis mechanisms in hepatocellular carcinoma(HCC).However,it seems that no one have focused on predicting VETC status in small HCC(sHCC).This study aimed to develop a new nomogram for predicting VETC positivity using preoperative clinical data and image features in sHCC(≤3 cm)*** To construct a nomogram that combines preoperative clinical parameters and image features to predict patterns of VETC and evaluate the prognosis of sHCC *** A total of 309 patients with sHCC,who underwent segmental resection and had their VETC status confirmed,were included in the *** patients were recruited from three different hospitals:Hospital 1 contributed 177 patients for the training set,Hospital 2 provided 78 patients for the test set,and Hospital 3 provided 54 patients for the validation *** predictors of VETC were identified through univariate and multivariate logistic *** independent predictors were then used to construct a VETC prediction model for *** model’s performance was evaluated using the area under the curve(AUC),calibration curve,and clinical decision ***,Kaplan-Meier survival analysis was performed to confirm whether the predicted VETC status by the model is associated with early recurrence,just as it is with the actual VETC status and early *** Alpha-fetoprotein_lg10,carbohydrate antigen 199,irregular shape,non-smooth margin,and arterial peritumoral enhancement were identified as independent predictors of *** model incorporating these predictors demonstrated strong predictive *** AUC was 0.811 for the training set,0.800 for the test set,and 0.791 for the validation *** calibration curve indicated that the predicted probability was consistent with the actual VETC status in all three ***,the decision curve analysis demonstr

关键词： Small hepatocellular carcinoma Vessels encapsulating tumor clusters Nomogram Magnetic resonance imaging Multicenter

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纤维增强树脂基复合材料筋/拉索数值模拟研究综述

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复合材料学报 2024年第4期41卷 1653-1671页

作者：朱江涛赵杏南京航空航天大学民航学院南京210016

纤维增强树脂基复合材料(FRP)是由纤维和树脂基体组合而成的一种材料,在各种领域中拥有广泛的应用。利用数值模拟方法可以更加简单、精确地预测FRP筋/拉索性能,从而加快设计效率、减少试验工作量,因此大量学者针对FRP筋/拉索进行了数值... 详细信息

纤维增强树脂基复合材料(FRP)是由纤维和树脂基体组合而成的一种材料,在各种领域中拥有广泛的应用。利用数值模拟方法可以更加简单、精确地预测FRP筋/拉索性能,从而加快设计效率、减少试验工作量,因此大量学者针对FRP筋/拉索进行了数值模拟研究。本文主要介绍了单向纤维增强聚合物复合材料的模拟控制因素和需求,在微观、细观和宏观尺度下研究FRP的理论模型和分析方法,提出了在不同尺度下对FRP筋/拉索进行数值模拟的不足之处及数值模拟在微观、细观和宏观层面中的应用。重点论述了不同尺度数值模拟方法在FRP筋/拉索中的应用和最新多尺度数值研究进展及FRP筋/拉索在锚固区的数值模拟方法及现状,最后简要阐述了FRP筋/拉索数值模拟在未来可能的研究发展方向。为建立精细化FRP筋/拉索损伤和性能预测模型发展提供参考。

关键词： FRP结构数值模拟多尺度分析有限元法耐久性

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X射线CT正交基材料分解成像方法及其在校正金属伪影中的应用

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光学学报 2024年第8期44卷 37-51页

作者：罗婷赵星赵云松李陶中国人民公安大学信息网络安全学院北京100038 首都师范大学数学科学学院北京100048 首都师范大学检测成像北京市高等学校工程研究中心北京100048 北京工商大学数学与统计学院北京100048

针对被测样品的组成物质已知且彼此不混合的情况,提出了一种结合能谱信息的单能谱计算机断层扫描(CT)图像重建方法。该方法利用已知物质作为基材料对CT投影数据的采集过程进行数学建模,然后对该非线性模型进行基材料图像的迭代求解。在... 详细信息

针对被测样品的组成物质已知且彼此不混合的情况,提出了一种结合能谱信息的单能谱计算机断层扫描(CT)图像重建方法。该方法利用已知物质作为基材料对CT投影数据的采集过程进行数学建模,然后对该非线性模型进行基材料图像的迭代求解。在求解中,通过将基材料“不混合”的性质转化为向量正交性,实现了迭代过程的快速收敛。本文方法充分考虑了X射线的能谱和被测样品材料的属性,可显著地校正传统CT图像中的硬化伪影和金属伪影,有效地提高该类样品的CT成像质量。实验验证了所提方法的有效性。

关键词：成像系统 X射线计算机断层扫描硬化伪影金属伪影基材料分解

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椎基静脉孔的解剖学和生物力学特征及其临床意义

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浙江大学学报（医学版） 2024年第4期53卷 443-449页

作者：李生鋆赵兴浙江大学医学院附属邵逸夫医院骨科浙江杭州310016

椎基静脉孔是椎体后壁的皮质缺损区域,在人类及常见哺乳动物中均有存在,是椎基静脉、腰动脉分支、脊神经返支等结构进出椎体的天然孔道,其存在改变了椎体局部微结构,导致椎体中部区域皮质骨缺损及骨小梁稀疏,进而影响了椎体的生物力学特... 详细信息

椎基静脉孔是椎体后壁的皮质缺损区域,在人类及常见哺乳动物中均有存在,是椎基静脉、腰动脉分支、脊神经返支等结构进出椎体的天然孔道,其存在改变了椎体局部微结构,导致椎体中部区域皮质骨缺损及骨小梁稀疏,进而影响了椎体的生物力学特征,使椎体中部成为椎体的一个“薄弱”区域。在椎体内,部分特征性损伤的产生与椎基静脉孔有关,如椎体压缩性骨折及骨折不愈合产生的椎体裂隙征、椎体爆裂性骨折及椎体后上缘骨折块,以及治疗过程中产生的骨水泥漏等。本文就椎基静脉孔的解剖学特征、发育生物学特征、椎基静脉孔对生物力学特征的影响、椎基静脉孔相关的椎体疾病及治疗进行综述,以期为临床椎体骨折诊疗提供参考。

关键词：椎基静脉孔解剖学生物力学椎体疾病综述

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论符号现象学的形成

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内蒙古社会科学 2024年第4期45卷 46-52页

作者：赵星植四川大学外国语学院四川成都610064

符号现象学的形成源自皮尔斯的符号思想理论体系。皮尔斯对现象问题的思考不仅奠定了符号学理论的基础,而且也为当今哲学符号学研究提供了重要的理论支撑。皮尔斯在其现象学手稿中清晰地论证了三种普遍范畴的存在方式与特性,以及三种范... 详细信息

符号现象学的形成源自皮尔斯的符号思想理论体系。皮尔斯对现象问题的思考不仅奠定了符号学理论的基础,而且也为当今哲学符号学研究提供了重要的理论支撑。皮尔斯在其现象学手稿中清晰地论证了三种普遍范畴的存在方式与特性,以及三种范畴与人类意识活动之相互关系,这为探究文学艺术中日益凸显的意义与意识问题提供了理论资源。

关键词：符号学现象学皮尔斯范畴意识意义

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地方高校发展范式转型的路径黏性:现实表征、迟滞效应与化解策略

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黑龙江高教研究 2024年第5期42卷 13-18页

作者：赵幸熊进湖北师范大学湖北黄石435002 南宁师范大学广西南宁530001

在新时代背景下,实现从高速增长到高质量发展的转型既是地方高校发展范式转型的重要议题,也是地方高校发展赋能高等教育现代化建设的历史使然。受沉淀成本、路径依赖以及信息不对称等多重因素的影响,地方高校发展范式的转型可能会出现... 详细信息

在新时代背景下,实现从高速增长到高质量发展的转型既是地方高校发展范式转型的重要议题,也是地方高校发展赋能高等教育现代化建设的历史使然。受沉淀成本、路径依赖以及信息不对称等多重因素的影响,地方高校发展范式的转型可能会出现理念黏性、制度黏性和治理黏性等路径黏性问题。路径黏性的存在必然会产生迟滞地方高校的发展结构优化、发展方式转变和发展动力转换等效应,从而迟滞其从高速增长范式转向高质量发展范式。基于此,推动地方高校从高速增长向高质量发展的范式转型,应做到:破除理念黏性,彰显“地方”之特色与价值;扭转制度黏性,构建地方高校评价的“理性”之维;突破治理黏性,再造地方高校治理工具。

关键词：地方高校发展范式转型理念黏性制度黏性治理黏性

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