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A semi-analytical method for forced vibration analysis of cracked laminated composite beam with general boundary condition

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Journal of Ocean Engineering and Science 2021年第1期6卷 40-53页

作者： Sok Kim Kwanghun Kim myongchol.ri Yongsong Paek Choljun Kim Department of Information Engineering Chongjin Mine&Metal UniversityChongjin 999091Democratic People’s Republic of Korea Department of Engineering Machine Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea Institute of Science Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea Department of Resources Development Mechanical Engineering Pyongyang University of Mechanical EngineeringPyongyang 999093Democratic People’s Republic of Korea

In this paper,a semi-analytical method for the forced vibration analysis of cracked laminated composite beam(CLCB)is *** computational model is formulated by Timoshenko beam theory and its dynamic solution is solved using the Jacobi-ritz *** boundary conditions(BCs)at both ends of the CLCB are generalized by the application of artificial elastic springs,the CLCB is separated into two elements along the crack,the flexibility coefficient of fracture theory is used to model the essential continuous condition of the connective *** the allowable displacement functions used to analyze dynamic characteristics of CLCB are expressed by classical Jacobi orthogonal polynomials in a more general *** accuracy of the proposed method is verified through the compare with results of the finite element method(software ABAQUS is used in this paper).On this basis,the parametric study for dynamic analysis characteristics of CLCB is performed to provide reference datum for engineers.

关键词： Semi-analytical method Cracked laminated composite beam(CLCB) Dynamic analysis General boundary condition Numerical analysis

Effects of increasing the degree of building height asymmetry on ventilation and pollutant dispersion within street canyons

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Energy and Built Environment 2024年第5期5卷 727-740页

作者： Kwang Song Jon Song Il Jong Sung Hyok ri Ju Yon Ko Sung Gi Ko Hun Kim Tok Song Ryang Chung Hyok Sin School of Environment and Architecture University of Shanghai for Science and TechnologyShanghai 200093China School of Metallic Engineering Kim Chaek University of TechnologyCentral DistrictPyongyang 900093Democratic People’s Republic of Korea Faculty of Physics Kim Chaek University of TechnologyCentral DistrictPyongyang 900093Democratic People’s Republic of Korea Natural Science Center Kim Il Sung UniversityTaesong DistrictPyongyang 900093Democratic People’s Republic of Korea

Rational urban design helps to build sustainable cities with high ventilation capacity and pollutant removal ca-pacity,but the effect of building height on ventilation and pollutant dispersion inside asymmetric canyons has not been fully *** this paper,we studied the effect of increasing the degree of building height asym-metry(DBHA)on canyon ventilation and pollutant diffusion in shallow and deep asymmetric street canyons by considering six different building height ratios(BHR=3/4,1/2,1/3,4/3,2/1 and 3/1).The results show that increasing the DBHA in asymmetric canyons can improve the ventilation and pollutant removal *** step-up canyons,increasing the downwind building height is very useful to improve ventilation and pollutant *** shallow/deep step-up canyons with BHR=1/3,the air exchange rate(ACH)increased to 211.2%and 380.1%of the flat canyons,*** spatially-average pollutant concentration in the pedestrian zones(leeward Kavg∗ang windward Kavg∗)decreases significantly with the increase of DBHA,especially for the deep step-up canyon with BHR=1/3,the leeward Kavg∗and windward Kavg∗decrease to 15.3%and 3%,***,increasing the upwind building height can also improve the ventilation capacity in the step-down *** the deep step-down canyon with BHR=3/1,the leeward Kavg∗and windward Kavg∗decreased to 40.6%and 24.1%of the deep flat canyon,***,the ventilation capacity is very low for step-down canyons with BHR=4/3,and for step-down canyons with BHR≥2/1,the ventilation capacity and pollutant removal capacity increase significantly with the increase of ***,in urban planning,step-down canyons with BHR=4/3 should be avoided and designed to satisfy the condition of BHR≥2/*** findings will be a valuable reference for urban designers to build sustainable cities with high ventilation capacity.

关键词： Building height Asymmetric street canyon Ventilation Traffic pollutant Sustainable city

Effect of an Airbag-selective Portal Vein Blood Arrester on the Liver after Hepatectomy:A New Technique for Selective Clamping of the Portal Vein

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Current Medical Science 2024年第2期44卷 380-390页

作者： Ce-xiong FU Xiao-ri QIN Jin-song CHEN Jie ZHONG Yu-xu XIE Bi-dan LI Qing-qing FU Fang LI Jin-fang ZHENG Department of Hepatobiliary and Pancreatic Surgery Hainan General HospitalHainan Affiliated Hospital of Hainan Medical UniversityHaikou 570311China University of South China Hengyang 421001China Department of Gastroenterology Gastroenterology Endoscopy CenterHainan General HospitalHainan Affiliated Hospital of Hainan Medical UniversityHaikou 57031lChina Center of Clinical Laboratory Hainan General HospitalHainan Affiliated Hospital of Hainan Medical UniversityHaikou 570311China Department of Radiology Hainan General HospitalHainan Affiliated Hospital of Hainan Medical UniversityHaikou 570311China

Objective:A novel technique was explored using an airbag-selective portal vein blood arrester that circumvents the need for an intraoperative assessment of anatomical variations in patients with complex intrahepatic space-occupying ***:Rabbits undergoing hepatectomy were randomly assigned to 4 groups:intermittent portal triad clamping(PTC),intermittent portal vein clamping(PVC),intermittent portal vein blocker with an airbag-selective portal vein blood arrester(APC),and without portal blood occlusion(control).Hepatic ischemia and reperfusion injury were assessed by measuring the 7-day survival rate,blood loss,liver function,hepatic pathology,hepatic inflammatory cytokine infiltration,hepatic malondialdehyde levels,and proliferating cell nuclear antigen ***:Liver damage was substantially reduced in the APC and PVC *** APC animals exhibited transaminase levels similar to or less oxidative stress damage and inflammatory hepatocellular injury compared to those exhibited by the PVC *** was significantly higher in the control group than in the other *** APC group had less bleeding than the PVC group because of the avoidance of portal vein skeletonization during ***,more operative time was saved in the APC group than in the PVC ***,the total 7-day survival rate in the APC group was higher than that in the PTC ***:Airbag-selective portal vein blood arresters may help protect against hepatic ischemia and reperfusion injury in rabbits undergoing partial *** technique may also help prevent liver damage in patients requiring hepatectomy.

关键词： hepatectomy portal vein hepatic damage selective clamping

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基于催化裂化家族技术发展新型炼化一体化

化学研究与应用 2024年第9期36卷 1961-1967页

作者：许日中海油惠州石化有限公司广东惠州516086

重油流化催化裂化(RFCC)是重油轻质化核心工艺和车用燃料主要来源,近30年来,中国石化(Sinopec)石油化工科学研究院(riPP)主研并工业化了十五余项FCC家族系列专有技术,为RFCC作为重油轻质化和烯烃、芳烃化的炼化核心工艺奠定了技术基础... 详细信息

重油流化催化裂化(RFCC)是重油轻质化核心工艺和车用燃料主要来源,近30年来,中国石化(Sinopec)石油化工科学研究院(riPP)主研并工业化了十五余项FCC家族系列专有技术,为RFCC作为重油轻质化和烯烃、芳烃化的炼化核心工艺奠定了技术基础。针对环境保护对燃油的要求高,且炼制原料重质化、劣质化和炼油过剩而化工品紧缺的现状,结合对FCC家族技术的评述,提出以FCC家族系列技术为核心的一体化技术方案,包括:上游原料加氢预处理、下游油品质量升级、烯烃或芳烃深加工等规模相匹配的装置群,构成重油加工联合装置,实现了环境保护要求和“减油增化”目的,形成新型炼化一体化。

关键词：重油催化裂化环境保护 FCC家族系列技术联合装置炼化一体化

Performance of water-coupled charge blasting under different in-situ stresses

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Journal of Central South University 2024年第7期31卷 2300-2320页

作者： ZHOU Zi-long WANG Zhen CHENG Rui-shan CAI Xin LAN ri-yan School of Resources and Safety Engineering Central South UniversityChangsha 410083China Center for Infrastructural Monitoring and Protection School of Civil and Mechanical EngineeringCurtin UniversityBentleyAustralia Guangxi Xinfazhan Communication Group Co. Ltd.Nanning 530000China

Water-coupled charge blasting is a promising technique to efficiently break rock *** this study,numerical models of double boreholes with water-coupled charge are established using LS-DYNA and are calibrated by the tests of rock masses subjected to explosion loads to examine its *** crack levels of rock mass induced by water-coupled charge blasting and air-coupled charge blasting are first *** is found that water-coupled charge blasting is more appropriate to fracture deep rock mass than air-coupled charge *** addition,the effects of rock properties,water-coupled charge coefficients,and borehole connection angles on the performance of water-coupled charge blasting are *** results show that rock properties and water-coupled charge coefficients can greatly influence the crack and fragmentation levels of rock mass induced by water-coupled charge blasting under uniform and non-uniform in-situ ***,changing borehole-connection angles can only affect crack and fragmentation levels of rock mass under non-uniform in-situ stresses but barely affect those under uniform in-situ stresses.A formula is finally proposed by considering the above-mentioned factors to provide the design suggestion of water-coupled charge blasting to fracture rock mass with different in-situ stresses.

关键词： water-coupled blasting in-situ stress water-coupled charge coefficient rock type borehole-connection angle

Modulated noble metal/2D MOF heterostructures for improved hydrogen storage of MgH_(2)

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Rare Metals 2024年第4期43卷 1672-1685页

作者： Zeng-Yi Li Li-Xian Sun Fen Xu Yu-Mei Luo Yong-Peng Xia Sheng Wei Chen-Chen Zhang ri-Guang Cheng Chao-Feng Ye Meng-Yuan Liu Ju-Lan Zeng Zhong Cao Hong-Ge Pan School of Material Science and Engineering Guilin University of Electronic TechnologyGuilin541004China School of Chemistry and Chemical Engineering Changsha University of Science and TechnologyChangsha410114China Institute of Science and Technology for New Energy Xi’an Technological UniversityXi’an710021China

The conjugation of external species with twodimensional(2D)materials has broad application *** this study,we have explored the potential of noble metal/2D MOF heterostructures in hydrogen ***,the MgH_(2)-Ni-MOF@Pd system has shown remarkable hydrogen desorption/sorption performances,starting to liberate hydrogen at 1810C,which is 2300C lower than that of pristine *** the catalytic effect of Ni-MOF@Pd,the dehydrogenation apparent activation energy of MgH2 is noticeably decreased from(133.5±17.5)to(34.58±1.87)kJ·moL^(-1),and the hydrogenation apparent activation energy is reduced from(70.41±7.43)to(25.78±4.64)kJ·moL^(-1),which is lowered by 63.4%.The fully-dehydrogenated MgH2-NiMOF@Pd composite rapidly uptakes hydrogen,with 2.62wt%at 100℃and 6.06 wt%at 150℃within 300 s,*** mechanism analysis of MgH2 catalyzed by Ni-MOF@Pd has revealed that the transformation of Mg_2Ni and Mg_2NiH_4 could act as a"hydrogen pump",providing numerous channels for fast diffusion and transport of hydrogen ***,in the dehydrogenation process,the element Pd reacts with MgH_(2)to form the MgPd alloy phase,which makes MgH_(2)take precedence to decompose through the Mg-Pd alloy rather than self-decomposition,further reducing thermal stability and improving de/hydrogenation *** synergistic effect of Mg-Pd,Mg_2Ni,and the special ultra-thin 2D sheet structure of the additive is the main reason for the good hydrogen storage property of MgH_(2)-Ni-MOF@*** findings provide inspiration for designing efficient multifunctional additives with unique morphologies to optimize the hydrogen desorption/sorption behaviors of hydrogen storage materials.

关键词： Hydrogen storage Magnesium hydride 2D metal-organic framework nanosheets Ni/Pd Synergistic catalysis

Microstructure and properties of Cu matrix composites reinforced with surface-modified Kovar particles

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Transactions of Nonferrous Metals Society of China 2024年第10期34卷 3251-3264页

作者： Tao MENG ri-chu WANG Zhi-yong CAI Ying-jun YAO School of Materials Science and Engineering Central South UniversityChangsha 410083China Key Laboratory of Electronic Packaging and Advanced Functional Materials Central South UniversityChangsha 410083China

The thermal conductivity of Cu/Kovar composites was improved by suppressing element diffusion at the interfaces through the formation of FeWO_(4)coating on the Kovar particles via vacuum *** matrix composites reinforced with unmodified(Cu/Kovar)and modified Kovar(Cu/Kovar@)particles were prepared by hot *** results demonstrate that the interfaces of Cu/FeWO_(4)and FeWO_(4)/Kovar in the Cu/Kovar@composites exhibit strong bonding,and no secondary phase is *** presence of FeWO_(4)impedes interfacial diffusion within the composite,resulting in an increase in grain size and a decrease in dislocation *** surface modification of the Kovar particle,the thermal conductivity of Cu/Kovar@composite is increased by 110%from 40.6 to 85.6 W·m^(-1)·K^(-1).Moreover,the thermal expansion coefficient of the Cu/Kovar@composite is 9.8×10^(-6)K^(-1),meeting the electronic packaging requirements.

关键词： electronic packaging material Cu/Kovar composite surface modification thermal conductivity

A multi-platform analysis of human gingival crevicular fluid reveals ferroptosis as a relevant regulated cell death mechanism during the clinical progression of periodontitis

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International Journal of Oral Science 2024年第2期16卷 265-279页

作者： Alfredo Torres M.Angélica Michea Ákos Végvári Marion Arce Valentina Pérez Marcela Alcota Alicia Morales Rolando Vernal Mauricio Budini Roman A.Zubarev Fermín E.González Laboratory of Experimental Immunology&Cancer Faculty of DentistryUniversity of ChileSantiagoChile Department of Conservative Dentistry Faculty of DentistryUniversity of ChileSantiagoChile Division of Chemistry I Department of Medical Biochemistry and BiophysicsKarolinska InstitutetStockholmSweden Periodontal Biology Laboratory Faculty of DentistryUniversidad de ChileSantiagoChile Laboratory of Cellular and Molecular Pathology Institute for Research in Dental SciencesFaculty of DentistryUniversity of ChileSantiagoChile

Ferroptosis is implicated in the pathogenesis of numerous chronic-inflammatory diseases,yet its association with progressive periodontitis remains *** investigate the involvement and significance of ferroptosis in periodontitis progression,we assessed sixteen periodontitis-diagnosed *** progression was clinically monitored over twelve weeks via weekly clinical evaluations and gingival crevicular fluid(GCF)collection was performed for further *** metrics,proteomic data,in silico methods,and bioinformatics tools were combined to identify protein profiles linked to periodontitis progression and to explore their potential connection with *** western blot analyses validated key ***,a single-cell RNA sequencing(scRNA-seq)dataset(GSE164241)for gingival tissues was analyzed to elucidate cellular dynamics during periodontitis *** progression was identified as occurring at a faster rate than traditionally *** samples from progressing and non-progressing periodontal sites showed quantitative and qualitatively distinct proteomic *** addition,specific biological processes and molecular functions during progressive periodontitis were revealed and a set of hub proteins,including SNCA,CA1,HBB,SLC4A1,and ANK1 was strongly associated with the clinical progression status of ***,we found specific proteins-drivers or suppressors-associated with ferroptosis(SNCA,FTH1,HSPB1,CD44,and GCLC),revealing the co-occurrence of this specific type of regulated cell death during the clinical progression of ***,the integration of quantitative proteomic data with scRNA-seq analysis suggested the susceptibility of fibroblasts to *** analyses reveal proteins and processes linked to ferroptosis for the first time in periodontal patients,which offer new insights into the molecular mechanisms of progressive periodontal *** findings may le

关键词： finding progression faster

Death from Fat Embolism after Lipectomy in a Patient with Madelung’s Disease

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Journal of Forensic Science and Medicine 2024年第2期10卷 148-151页

作者： Xing-An Yang Teng-Fei Yang Fu Zhang Jiang-Wei Kong Zi-Lin Meng Xin-Biao Liao Pei-Yu Liang Dong-ri Li Department of Forensic Pathology School of Forensic MedicineSouthern Medical UniversityGuangzhouGuangdongChina Guangdong Public Security Department Forensic Pathology LabGuangzhouGuangdongChina

A 56-year-old man with a long history of alcoholism and a palpable raised mass about 23 cm×12 cm in size on his neck was diagnosed with Madelung’s disease(MD);the patient also had *** day 1,he underwent neck lipoma tissue resection and suddenly had dyspnea 9 h after the operation,which was followed by cardiac *** heart rate resuscitation,he developed a heartbeat,but he remained in a coma and died 9 days after the *** obvious pathological tracheal compression from a hematoma was observed while evaluating the patient’s neck on *** microscopy,the patient had an extensive pulmonary fat embolism,partial alveolar septal rupture and hemorrhage,and fat particles,and there was extensive infiltration of macrophages,which had phagocytosed fat particles,in the alveolar *** was also evidence of pulmonary infection and hypoxic-ischemic *** cause of death was postoperative pulmonary fat embolism resulting in pneumonia and central nervous system *** is the first report of a patient with MD who died of a fatal pulmonary fat embolism after neck lipoma tissue *** experts and clinicians should pay sufficient attention to this case.

关键词： Forensic pathology madelung’s disease pulmonary fat embolism