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Journal of Central South University 2024年第7期31卷 2150-2166页

作者： YANG Fei-peng WEN Tao ZHANG Lei WANG jian-ying HUANG Shi-long ji shou-xun YANG Hai-lin State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Brunel Centre for Advanced Solidification Technology(BCAST) Brunel University LondonUxbridgeMiddlesexUB83PHUnited Kingdom

In this study,the effect of inclination angles relative to the building direction in the additively manufactured eutectic Al-5Mg-2Si alloy was investigated through the laser powder bed fusion(LPBF).The microstructures and mechanical properties of the Al-5Mg-2Si alloy manufactured with different inclination angles(0°,30°,45°,60°and 90°)were reported and *** is found that the“semicircular”melt pool(MP)in the load bearing face of 0°sample was eventually transformed into“stripe-like”MP in the 90°sample,accompanied by an increased fraction of melt pool boundaries(MPBs).Moreover,the microstructural analysis revealed that the columnar-to-equiaxed transition(CET)of theα-Al grains and eutectic Mg2Si was completed in the 90°sample,which were significantly refined with the average size of 10.6μm and 0.44μm,*** is also found that the 90°sample exhibited good combination of strength and elongation(*** strength of 393 MPa,ultimate tensile strength of 483 MPa and elongation of 8.1%).The anisotropic mechanical properties were highly associated with the refined microstructures,thermal stress,and density of ***,the CET driven by inclination angles was attributed to the variation of thermal conditions inside the local MPs.

关键词： additive manufacturing aluminium alloys columnar-to-equiaxed transition anisotropy mechanical property

In-situ powder mixing for laser-based directed energy deposition of functionally graded materials

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Advances in Manufacturing 2024年第1期12卷 150-166页

作者： ji-Peng Chen shou-Chun Xie He Huang School of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing210037People’s Republic of China Nanjing Huirui Photoelectric Technology Co. LtdNanjing211121People’s Republic of China

The mixing of powders is a highly relevant field under additive manufacturing,however,it has attracted limited interest to *** in-situ mixing of various powders remains a significant *** paper proposes a new method utilizing a static mixer for the in-situ mixing of multiple powders through the laser-based directed energy deposition(DED)of functionally graded ***,a powder-mixing experimental platform was established;WC and 316L powders were selected for the mixing ***,scanning electron microscopy,energy dispersive spectroscopy,and image processing were used to visually evaluate the homogeneity and proportion of the in-situ mixed ***,powder-mixing simulations were conducted to determine the powder-mixing *** the simulations,a powder carrier gas flow field and particle mixing were ***,a WC/316L metal matrix composite sample was produced using laser-based DED to verify the application potential of the static *** was found that the static mixer could adjust the powder ratio online,and a response time of 1–2 s should be considered when adjusting the ratio of the mixed powder.A feasible approach for in-situ powder mixing for laser-based DED was demonstrated and investigated,creating the basis for functionally graded materials.

关键词： Laser Deposition Static mixer Powder mixing Functionally graded materials

New interaction solutions of the(2+1)-dimensional Nizhnik–Novikov–Veselov-type system and fusion phenomena

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Communications in Theoretical Physics 2024年第10期76卷 9-13页

作者： Guo-Hua Wang ji Lin shou-Feng Shen School of Information Engineering Taizhou Vocational College of Science & Technology Department of Physics Zhejiang Normal University Department of Applied Mathematics Zhejiang University of Technology

By means of the multilinear variable separation（MLVS） approach, new interaction solutions with low-dimensional arbitrary functions of the（2+1）-dimensional Nizhnik–Novikov–Veselovtype system are constructed. Four-dromion structure, ring-parabolic soliton structure and corresponding fusion phenomena for the physical quantity U =λ（lnf）xyare revealed for the first time. This MLVS approach can also be used to deal with the（2+1）-dimensional Sasa–Satsuma system.

关键词： fusion interaction solution multilinear variable separation NNV-type system

Effect of Fe addition on microstructure and mechanical properties of Al-9Mg-2.6Si Alloy

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Journal of Measurement Science and Instrumentation 2017年第3期8卷 295-299页

作者： YAN Feng ZHAO Yi-hong ji shou-xun School of Material Science and Engineering North University of China Taiyuan 030051 China Brunei Centre for Advanced Solidication Technology (BCAST) Brunei University UxbridgeMiddlesexUB8 3PH UK

This paper presents the effect of Fe on the microstructure and mechanical properties of Al-9Mg-2.6Si *** Feaddition in the Al-9Mg-2.6Si alloy can slightly increase the yield strength but decrease the *** a much higher Feaddition around1.6wt.%,the elongation of the alloy can still maintain a usable level of5%.This alloy has shown a high toleranceon the Fe contamination

关键词： aluminium alloys iron phase microstructure mechanical properties

Data-driven casting defect prediction model for sand casting based on random forest classification algorithm

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China Foundry 2024年第2期21卷 137-146页

作者： Bang Guan Dong-hong Wang Da Shu shou-qin Zhu Xiao-yuan ji Bao-de Sun Shanghai Key Lab of Advanced High-Temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Lab of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Hefei Casting and Forging Factory of Anhui Heli Co. LtdHefei 230000China State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

The complex sand-casting process combined with the interactions between process parameters makes it difficult to control the casting quality,resulting in a high scrap rate.A strategy based on a data-driven model was proposed to reduce casting defects and improve production efficiency,which includes the random forest(RF)classification model,the feature importance analysis,and the process parameters optimization with Monte Carlo *** collected data includes four types of defects and corresponding process parameters were used to construct the RF *** results show a recall rate above 90% for all *** Gini Index was used to assess the importance of the process parameters in the formation of various defects in the RF ***,the classification model was applied to different production conditions for quality *** the case of process parameters optimization for gas porosity defects,this model serves as an experimental process in the Monte Carlo method to estimate a better temperature *** prediction model,when applied to the factory,greatly improved the efficiency of defect *** show that the scrap rate decreased from 10.16% to 6.68%.

关键词： sand casting process data-driven method classification model quality prediction feature importance

Remarkably Enhanced Methane Sensing Performance at Room Temperature via Constructing a Self-Assembled Mulberry-Like ZnO/SnO_(2) Hierarchical Structure

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Energy & Environmental Materials 2024年第3期7卷 337-344页

作者： xun Li Tian Tan Wei ji Wanling Zhou Yuwen Bao Xiaohong Xia Zhangfan Zeng Yun Gao Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials School of Materials Science&EngineeringHubei UniversityWuhan 430062China School of Artificial Intelligence Hubei UniversityWuhan 430062China

Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane *** this work,a self-assembled mulberry-like ZnO/SnO_(2)hierarchical structure is constructed by a two-step hydrothermal *** resultant sensor works at room temperature with excellent response of~56.1%to 2000 ppm CH_(4)at 55%relative *** is found that the strain induced at the ZnO/SnO_(2)interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed O_(2)^(-)ions close to the interface,leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.

关键词： heterojunction methane sensor oxygen vacancy piezoelectric polarization ZnO/SnO_(2)hierarchical structure

Efficacy and safety of remimazolam in bronchoscopic sedation:A meta-analysis

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World Journal of Clinical Cases 2024年第6期12卷 1120-1129页

作者： Ying Zhou Cheng Zhao Yi-xun Tang ji-Tong Liu Department of Anesthesiology The First Affiliated Hospital of Hunan Normal University(Hunan Provincial People’s Hospital)Changsha 410005Hunan ProvinceChina Department of Anesthesiology Zhangjiajie People's HospitalZhangjiajie 427000Hunan ProvinceChina

BACKGROUND Remimazolam is a new benzodiazepine used for procedural sedation and general *** studies have used remimazolam for bendable *** To assess the safety and efficacy of remimazolam for sedation in patients undergoing bendable bronchoscopy by performing a meta-analysis of randomized controlled trials(RCTs).METHODS We searched the EMBASE,PubMed,Cochrane Library,and Web of Science databases for RCTs on bendable bronchoscopic procedural sedation with remimazolam vs conventional sedatives(CS).RESULTS Five studies with 1080 cases were *** had the same sedation success rate compared with CS[relative risk(RR):1.35,95%CI:0.60-3.05,P=0.474,I2=99.6%].However,remimazolam was associated with a lower incidence of hypotension(RR:0.61;95%CI:0.40-0.95,P=0.027;I2=65.1%)and a lower incidence of respiratory depression(RR:0.50,95%CI:0.33-0.77,P=0.002,I2=42.3%).A subgroup analysis showed a higher success rate of sedation with remimazolam than midazolam(RR:2.45,95%CI:1.76-3.42,P<0.001).Compared with propofol,the incidence of hypotension(RR:0.45,95%CI:0.32-0.64,P<0.001,I2=0.0%),respiratory depression(RR:0.48,95%CI:0.30-0.76,P=0.002,I2=78.4%),hypoxemia(RR:0.36,95%CI:0.15-0.87,P=0.023),and injection pain(RR:0.04,95%CI:0.01-0.28,P=0.001)were *** Remimazolam is safe and effective during *** sedation success rate was similar to that in the CS ***,remimazolam has a higher safety profile,with fewer inhibitory effects on respiration and circulation.

关键词： Remimazolam Bronchoscopy Procedural sedation Meta-analysis

Safety and efficacy comparison of remimazolam and propofol for intravenous anesthesia during gastroenteroscopic surgery of older patients:A meta-analysis

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World Journal of Clinical Cases 2024年第7期12卷 1272-1283页

作者： Fang-Zhuo Li Cheng Zhao Yi-xun Tang ji-Tong Liu Department of Anesthesiology The First Affiliated Hospital of Hunan Normal University(Hunan Provincial People’s Hospital)Changsha 410005Hunan ProvinceChina Department of Anesthesiology Zhangjiajie People's HospitalZhangjiajie 427000Hunan ProvinceChina

BACKGROUND Remimazolam is characterized by rapid action and inactive *** is used as the general anesthetic for many clinical *** this study,we performed a meta-analysis to evaluate whether remimazolam is superior to propofol for gastroenteroscopy in older *** To compare the adverse events and efficacy of remimazolam and propofol during gastroenteroscopy in older *** The PubMed,Web of Science,the Cochrane Library databases were queried for the relevant key words"remimazolam,""and propofol,""and gastrointestinal endoscopy or gastroscopy."The search scope was"Title and Abstract,"and the search was limited to human studies and publications in *** studies wherein remimazolam and propofol were compared were included for the *** We selected seven randomized controlled trials involving 1445 cases for the *** reduced the hypotension(relative risk,RR=0.44,95%CI:0.29-0.66,P=0.000),respiratory depression(RR=0.46,95%CI:0.30-0.70,P=0.000),injection pain(RR=0.12,95%CI:0.05-0.25,P=0.000),bradycardia(RR=0.37,95%CI:0.24-0.58,P=0.000),and time to discharge[weighted mean difference(WMD)=-0.58,95%CI:-0.97 to-0.18,P=0.005],compared to those after propofol *** obvious differences were observed for postoperative nausea and vomiting(RR=1.09,95%CI:0.97-1.24,P=0.151),dizziness(RR=0.77,95%CI:0.43-1.36,P=0.361),successful sedation rate(RR=0.96,95%CI:0.93-1.00,P=0.083),or the time to become fully alert(WMD=0.00,95%CI:-1.08-1.08,P=0.998).CONCLUSION Remimazolam appears to be safer than propofol for gastroenteroscopy in older ***,further studies are required to confirm these findings.

关键词： Remimazolam Propofol Gastroenteroscopy Anesthesia Older adults Sedation Adverse events

Degradation of warm permafrost and talik formation on the Qinghai-Tibet Plateau in 2006-2021

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Advances in Climate Change Research 2024年第2期15卷 275-284页

作者： Qi-Hang MEI ji CHEN You-Qian LIU shou-Hong ZHANG jing-Yi ZHAO Tian-Chun DONG Jun-Cheng WANG Yao-Jun ZHAO Beiluhe Observation and Research Station of Frozen Soil Engineering and Environment Key Laboratory of Cryospheric Science and Frozen Soil EngineeringNorthwest Institute of Eco-Environmental and ResourcesChinese Academy of SciencesLanzhou 730000China China Railway Qinghai-Tibet Group Co.Ltd Xining 810007China University of Chinese Academy of Sciences Beijing 100049China

Permafrost is degrading globally,particularly those with low thermal stability on the Qinghai-Tibet Plateau,owing to climate ***,the inadequacy of direct research on permafrost degradation based on in-situ monitoring limits the prediction of permafrost degradation and engineering *** study explored the processes and modes of permafrost degradation into talik by analyzing ground temperature data from five points in the hinterland of the Qinghai-Tibet Plateau from 2006 to *** results showed that the degradation of the warm permafrost layer with a geothermal gradient of zero occurred simultaneously in the top and bottom *** rate of permafrost degradation from the top down and bottom up increase during the degradation process,but the increase of the former is more drastic after the formation of thawed ***,the construction of the Qinghai-Tibet Railway changed the degradation modes of the permafrost in adjacent natural sites through horizontal heat transfer,particularly after through talik formation under the *** findings suggest that taking countermeasures before or immediately after forming thawed interlayer is more *** evaluating the thermal impact of projects in warm permafrost regions,special attention should be given to the horizontal heat transfer process that may result from the formation of a through talik.

关键词： Warm permafrost Degradation Talik Qinghai-Tibet Plateau Climate change

Pain perception enhancement in consecutive secondeye phacoemulsification cataract surgeries under topical anesthesia

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International Journal of Ophthalmology(English edition) 2024年第8期17卷 1510-1518页

作者： jia-Wei Luo Yan-Hua Chen jian-Feng Yu Yi-xun Chen Min ji Huai-jin Guan Eye Institute Affiliated Hospital of Nantong UniversityMedical School of Nantong UniversityNantong 226001Jiangsu ProvinceChina Nantong Center for Disease Control and Prevention Nantong 226001Jiangsu ProvinceChina

Cataract is the main cause of visual impairment and blindness worldwide while the only effective cure for cataract is still *** phacoemulsification under topical anesthesia has been the routine procedure for cataract ***,patients often grumbled that they felt more painful during the second-eye surgery compared to the first-eye *** intraoperative pain experience has negative influence on satisfaction and willingness for second-eye cataract surgery of patients with bilateral *** ocular pain is a complicated process induced by the nociceptors activation in the peripheral nervous ***,neuropsychological,and pharmacological factors work together in the enhancement of intraoperative *** published literatures have focused on the pain enhancement during the secondeye phacoemulsification *** this review,we searched PubMed database for articles associated with pain perception differences between consecutive cataract surgeries published up to Feb.1,*** summarized the recent research progress in mechanisms and interventions for pain perception enhancement in consecutive secondeye phacoemulsification cataract *** review aimed to provide novel insights into strategies for improving patients’intraoperative experience in second-eye cataract surgeries.

关键词： ocular pain cataract surgery topical anesthesia intraoperative experience second-eye phacoemulsification