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Aggregation of CeAlO_(3) inclusions in heavy ingot of a steel containing 0.007% aluminum

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Journal of Iron and Steel Research International 2024年第8期31卷 1960-1972页

作者： Qiu-yue Zhou Jun-tao ba Lun Zhang Wei Chen Ying Ren Li-feng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

The distribution of inclusions at the bottom of a Ce-treated heavy steel ingot was detected and *** three-dimensional morphology and spatial distribution of CeAlOs clusters were characterized using the electrolytic extraction and Micro-CT detection.A model of inclusion collision to predict the aggregation of CeAlO_(3) inclusions in the ingot was established and validated by measured *** were mainly CeAlO_(3) and a small amount of Ce_(2)O_(2)S in the tundish after cerium *** collision and aggregation of inclusions led to the formation of large clusters in the ingot during the solidification *** slag entrainment inclusions,large CeAO_(3) clusters and small CeAlO_(3) particles were observed from the center to the edge of the ingot *** inclusions were mainly concentrated at the *** number density of inclusions larger than 200μm was 0.21 mm^(-3).The maximum diameter of CeA1O_(3) clusters was 1340μ*** the edge to the radial center and from the bottom to the top,the average diameter of inclusions gradually increased due to the longer solidification time of the ingot.

关键词： Inclusion Heavy ingot Cerium treatment Collision

Aviation Safety and data Mining in Marketing dimension

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Advances in Aerospace Science and Technology 2024年第3期9卷 117-127页

作者： Sevgi Adigüzel Murat başal Emel Saraç Transportation Services department Iğdır University Iğdır Türkiye Vocational School Istanbul Gelisim University Istanbul Türkiye department of Business Administration Institute of Social Sciences Ostim Technical University Ankara Türkiye

The aviation industry is a sector that is developing, changing and growing every day in terms of technological and legal framework. There are generally three factors that enable airlines to hold on to the market. These factors are safety, service quality and price. Airline companies can analyze the customers in the market with a focus on price and quality and develop a business model according to their expectations. For example, business class and economy class passenger expectations are different from each other, so the service and price to be offered to them will be different. However, all customers have one common expectation and that is safety. No matter how high quality the service is or how cheap the price is, no one wants to fly with an airline or plane that is not safe. From an airline company’s point of view, an accident or breakdown of one of the company’s aircraft can cause irreparable image loss and financial damage. If we look at past examples, we see that there are many airline companies or maintenance organizations that could not recover after an accident and went bankrupt. Safety is an indispensable factor. Therefore, there is a unit in the sector called the safety management system (SMS), which collects data by taking a proactive and reactive approach. The way and purpose of the safety management system is to take a proactive approach to recognize and prevent unsafe situations before they cause accidents or breakdowns, or to take a reactive approach to find the causes of accidents and breakdowns that have occurred as a result of certain factors and to take the necessary measures to prevent the same situations from happening again in the sector. The field of data mining, which is necessary to predict the future behavior of customers in the field of marketing, is an area that marketing also values. In this study, data mining studies to ensure safety in the aviation industry and the security of customer information in marketing will be emphasized, firs

关键词： data Mining Aviation Customer Safety Marketing

Phenotypic detection of Enterobacterales Strains Susceptible of Producing OXA-48 Carbapenemase

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Advances in Microbiology 2024年第2期14卷 115-121页

作者： Abdoulaye Seck Abdou diop babacar Ndiaye Assane dieng Awa ba Amadou diop Chantal Mahou douala-djemba Thierno Abdoulaye diallo Cheikh Anta diop University of dakar Dakar Senegal Medical Biology Laboratory Pasteur Institute of Dakar Dakar Senegal

background: Nowadays, emergence of Carbapenemase-Producing Enterobacterales (CPE) throughout the world has become a public health problem, especially in countries with limited resources. In recent years, CPE of type OXA-48 (Ambler class d) have been identified in dakar. The aim of this study was to evaluate the phenotypic detection of OXA-48 CPE using a temocillin disc (30 μg). Methodology: A retrospective study was carried out at Medical Biology Laboratory of Pasteur Institute in dakar on Ertapenem-Resistant Enterobacterales (ERE) strains isolated from 2015 to 2017. These strains were then tested with a 30 μg temocillin disc. Any strain resistant to temocillin (inhibition diameter Results: Forty-one ERE isolated during the study period were tested, of which 34 (82.9%) were OXA-48 based on phenotypic detection using temocillin disc and confirmed by PCR (100%). OXA-48 CPE strains detected were composed of Klebsiella pneumoniae (n = 14;41.2%), Enterobacter cloacae (n = 8;23.5%), Escherichia coli (n = 7, 20.5%), Citrobacter freundii (n = 3;8.8%), Cronobacter sakazakii (n = 1;3%) and Morganella morganii (n = 1;3%). Conclusion: Temocillin resistance has a good positive predictive value for detecting OXA-48 CPE by phenotypic method, confirmed by PCR. Temocillin is therefore a good marker for detection of OXA-48 CPE except Hafnia alvei.

关键词： Ertapenem Temocillin Phenotypic detection Carbapenemase-Producing Enterobacterales OXA-48

基于davidenkov本构模型的三维沉积盆地非线性地震动谱元法模拟

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岩土工程学报 2024年第7期46卷 1387-1397页

作者：巴振宁赵靖轩桑巧稚梁建文滨海土木工程结构与安全教育部重点实验室天津300350 天津大学中国地震局地震工程综合模拟与城乡抗震韧性重点实验室天津300350 天津大学土木工程系天津300350 同济大学地下建筑与工程系上海200092

为研究三维沉积盆地内低波速土体非线性反应对近断层地震动的影响,实现基于物理的全过程(震源破裂-地震波传播-复杂场地效应-近地表土体非线性反应)三维复杂场地地震动模拟,在谱元SPECFEM3d程序中进行二次开发,采用目前具有丰富工程应... 详细信息

为研究三维沉积盆地内低波速土体非线性反应对近断层地震动的影响,实现基于物理的全过程(震源破裂-地震波传播-复杂场地效应-近地表土体非线性反应)三维复杂场地地震动模拟,在谱元SPECFEM3d程序中进行二次开发,采用目前具有丰富工程应用且适用于不同土类的三参数Martin-Seed-davidenkov本构模型,结合已有的不规则加卸载准则,通过在程序中修改每个显式时间步下的应力增量,实现了土体剪切模量的实时更新和加卸载拐点的有效识别,将土体的非线性特性纳入到三维复杂场地地震动模拟中。首先将建立的三维模型通过施加合理边界退化至一维,与一维非线性动力分析软件dEEPSOIL的结果进行了对比,验证了开发的正确性;进而将开发的程序应用于中国滇西南地区施甸盆地的非线性地震动模拟,并与相应的线性结果进行了对比。结果显示,受土体非线性的影响,施甸地区PGA和PGV较线性结果峰值均降低,且非线性土体对PGV的影响更加明显,较线性结果最大降低约30%;沉积非线性使沉积内部观测点的速度及其反应谱幅值降低,且特征频率向长周期方向移动。

关键词：非线性地震反应三维沉积盆地 davidenkov本构模型谱元法

基于FK-FE混合方法的位错点源作用下全过程结构地震反应模拟

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工程力学 2024年第4期41卷 184-198页

作者：巴振宁鲁世斌付继赛梁建文芦燕中国地震局地震工程综合模拟与城乡抗震韧性重点实验室天津300354 天津大学土木工程系天津300354

基于区域缩减思想,集整基于精确动力刚度矩阵的频率波数域(FK)半解析方法和有限元(FE)数值方法各自优势(FK精确高效模拟一维波速结构地震波传播;FEM具有丰富单元和本构类型,可精细模拟工程结构地震反应),提出了一种从震源到工程结构全... 详细信息

基于区域缩减思想,集整基于精确动力刚度矩阵的频率波数域(FK)半解析方法和有限元(FE)数值方法各自优势(FK精确高效模拟一维波速结构地震波传播;FEM具有丰富单元和本构类型,可精细模拟工程结构地震反应),提出了一种从震源到工程结构全过程地震反应模拟的FK-FE混合方法。并将FK代码作为插件二次开发到大型商业有限元软件AbaQUS中,实现了AbaQUS平台下从震源到工程结构的全过程宽频地震反应物理模拟。验证了FK-FE混合方法正确性,进而将其应用于位错点源作用下美国SAC机构设计的9层Benchmark抗弯钢框架结构全过程0 Hz~15 Hz宽频地震反应模拟,重点探讨了地壳层波速结构和近地表场地条件对框架结构地震反应的影响。研究表明:地壳层速度结构和场地类别对该结构的地震反应均有显著影响,地壳层速度结构3(较硬)相比速度结构1(较软),结构最大位移和层间位移角分别减小了22.7%和62.0%;Ⅱ类场地相较于Ⅳ类场地,结构最大位移和层间位移角分别减小了22.3%和44.7%。

关键词：地震反应位错点源 FK-FE混合方法区域缩减全过程模拟

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数字化三维重建技术在文物管理中的应用

集成电路应用 2024年第2期41卷 246-247页

作者：把元霄兰州职业技术学院甘肃730207

阐述文物数字化三维重建技术的特点,分析文物数字化技术应用的原理,探讨文物数字化三维重建过程,包括稠密点云生成、类八叉树聚类算法去噪、泊松曲面重建。

关键词：数字化技术三维重建技术聚类算法去噪

基于动态知识流动特征的有向技术融合预测方法

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情报杂志 2024年第8期43卷 152-159,41页

作者：陈稳马亚雪巴志超李纲南京大学数据智能与交叉创新实验室南京210023 南京大学数据管理创新研究中心苏州215163 南京大学信息管理学院南京210023 武汉大学信息管理学院武汉430072

[研究目的]基于动态知识流动特征对有向的技术融合关系进行预测,有助于提高企业的研发效率及科技管理部门对科技资源的合理分配。[研究方法]首先,将IPC前4位代码作为技术单元,基于专利中主分类号与副分类号提取技术间的有向知识流动关系... 详细信息

[研究目的]基于动态知识流动特征对有向的技术融合关系进行预测,有助于提高企业的研发效率及科技管理部门对科技资源的合理分配。[研究方法]首先,将IPC前4位代码作为技术单元,基于专利中主分类号与副分类号提取技术间的有向知识流动关系;然后,借鉴关联规则挖掘算法从重要性、强度和依赖度3个维度对知识流动关系进行筛选,将满足指标阈值的知识流动关系作为有向技术融合关系;最后,将有向技术融合关系预测转化为有监督的二分类任务,以机器学习算法为模型基础,结合前两个时期的技术间知识流动特征及其时序变化特征,预测下一个时期内的技术间是否存在技术融合关系。[研究结论]增材制造领域的实证分析结果显示,以代价敏感机器学习算法为预测算法,基于前两个时期的技术间知识流动特征及其时序变化特征可以有效预测下一阶段中的技术融合。随着技术的发展,技术间的单向融合愈发频繁,并逐渐演变为技术双向融合,甚至呈现多技术融合的现象。

关键词：技术融合专利分类号知识流技术预测增材制造机器学习知识流动特征

硫化铅胶体量子点的溶剂工程及光电器件性能研究

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复旦学报（自然科学版） 2024年第3期63卷 320-328页

作者：廖凯巴坤严亚杰梁子骐复旦大学材料科学系上海200433

量子点光电器件以近红外吸收的硫化铅(PbS)胶体量子点(CQds)为代表,因其带隙可调、吸收系数高、具备多激子效应和可溶液化加工等优点而受到广泛关注。然而,囿于胶体稳定性,PbS CQds光电器件大规模制备困难、商业化进度迟缓。为解决该问... 详细信息

量子点光电器件以近红外吸收的硫化铅(PbS)胶体量子点(CQds)为代表,因其带隙可调、吸收系数高、具备多激子效应和可溶液化加工等优点而受到广泛关注。然而,囿于胶体稳定性,PbS CQds光电器件大规模制备困难、商业化进度迟缓。为解决该问题,本工作首先通过配体交换制备了溶液稳定性良好的量子点,进而开发了新型正丁胺/氯苯混合溶剂。以正丁胺为溶剂的量子点在空气条件下最多保存3 d,而以正丁胺/氯苯为溶剂的量子点可以保存至少15 d。紫外可见吸收光谱和荧光光谱结果显示混合溶剂中的量子点表现出优异的尺寸均一性。最终,通过该溶剂工程制备的PbS CQds太阳能电池器件光电转换效率达到了5.18%,光电探测器的响应度和探测率分别为0.18 A·W^(-1)和1.05×10^(12)Jones。

关键词：硫化铅胶体量子点溶剂工程溶液稳定性光电器件

Mother-to-Child Transmission of Human Papillomavirus in Burkina Faso

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American Journal of Molecular Biology 2024年第1期14卷 13-24页

作者： Koudpoko Madeleine Kabre djénéba Ouermi Théodora Mahoukèdè Zohoncon Fatié Porzé Wilfried Traore Prosper bado Abdoul Karim Ouattara Ouamini Pulchérie de Prisca Gnoumou Rogomenoma Alice Ouedraogo Albert Théophane Yonli Punya Akouélé Kuassi-Kpede Charlemagne Marie Ragnag-Néwendé Ouedraogo Jacques Simpore Laboratoire de Biologie Moléculaire et de Génétique (LABIOGENE) Université Joseph KI-ZERBO Ouagadougou Burkina Faso Centre de Recherche Biomoléculaire Pietro Annigoni (CERba) Ouagadougou Burkina Faso Faculté des Sciences de la Santé Université Saint Thomas d’Aquin Ouagadougou Burkina Faso Laboratoire de Biologie Moléculaire H&#244pital Saint Camille de Ouagadougou (HOSCO) Ouagadougou Burkina Faso University Joseph Ki-Zerbo UFR/SDS Ouagadougou Burkina Faso

Introduction: Human papillomavirus (HPV) infection is the most widespread sexually transmitted infection in the world. Today, there is growing evidence that HPV can be transmitted early in life, and one potential route is mother-to-child transmission. data on this route of HPV transmission are scarce in Africa and particularly in Burkina Faso, where no data on the subject are yet available. The aim of our study was to estimate the rate of mother-to-child transmission of HPV infection and to identify circulating genotypes. Methodology: Cervico-uterine samples were collected from 100 full-term pregnant women and, buccal samples were obtained from their newborns at Hopital Saint Camille de Ouagadougou (HOSCO) by the specialist physician. HPV dNA amplification and genotyping were performed by PCR followed by hybridization using the HPV direct Flow Chips kit, detecting 36 genotypes including 18 high-risk and 18 low-risk. Results: The prevalence of HPV in newborns was 8% (8/100). Six (6) HPV-positive neonates had HPV-positive mothers, while 2 HPV-positive neonates had HPV-negative mothers. The vertical transmission rate was 26.09% (6/23). Mother-newborn genotypes were concordant. However, the genotype profile of the newborns was more restricted than that of the mothers. Conclusion: HPV dNA was found in 8% of newborns in our study. The genotype profile of the mother-newborn pair was concordant. Asymptomatic HPV infection in a pregnant woman could constitute a risk factor for vertical transmission.

关键词： Mother-to-Child Transmission Human Papillomavirus PCR Genotypes Burkina Faso