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Improvement of impact properties of Al-Si-Mg alloy via solution treatment and joint modification with Sr and La

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Rare Metals 2024年第7期43卷 3301-3313页

作者： Xiong-Ling Zheng Shao-Xiang Li Jia-Le Ma Qing-Yan Xu Hai-Dong Zhao zhi-qiang Han Key Laboratory for Advanced Materials Processing Technology Ministry of EducationSchool of Materials Science and EngineeringTsinghua University National Engineering Research Center of Near-Net Shape Forming for Metallic Materials South China University of Technology

An effort to obtain superior impact properties for Al-7Si-0.35 Mg alloy is presented,where modification with 0.02 wt% Sr and 0.1 wt% La as well as solution treatment was jointly *** samples were solution treated at 535℃ for 15 min to 12 *** microstructure,fracture mechanism,and their correlation with the impact properties of the alloy were studied in detail mainly through optical microscopy（OM）,scanning electron microscopy（SEM） and oscillography impact *** results show that the addition of Sr and La refined the eutectic Si particles significantly from～ 2.05 μm（modified with Sr alone） to～ 0.75 μm in as-cast microstructure,leading to a very homogeneous distribution of spheroidized Si particles in the alloy solution treated at 535℃ for 8 *** alloy exhibits excellent impact toughness up to 75 J·cm-2,which is much higher than the maximum impact toughness of the alloys modified by Sr alone(～ 46 J·cm-2).The major reason for this remarkable increase in the impact property is the dramatic increase in crack initiation *** dispersoid-free zones（DFZs）near the eutectic regions mainly consist of the ductile Al-matrix,which exhibits excellent *** ductile Al-matrix of the DFZs hinders the crack propagation,resulting in a significant increase in crack propagation energy.

关键词： Aluminum alloys Modification Solution treatment Microstructure Impact properties Fracture mechanism

Influence of heat treatment on microstructure,mechanical and corrosion behavior of WE43 alloy fabricated by laser-beam powder bed fusion

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International Journal of Extreme Manufacturing 2024年第1期6卷 258-275页

作者： Chenrong Ling qiang Li Zhe Zhang Youwen Yang Wenhao Zhou Wenlong Chen zhi Dong Chunrong Pan Cijun Shuai College of Mechanical and Electrical Engineering Jiangxi University of Science and TechnologyGanzhou 341000People’s Republic of China School of Mechanical and Electronic Engineering Suzhou UniversitySuzhou 234000People’s Republic of China Shaanxi Key Laboratory of Biomedical Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016People’s Republic of China Department of Orthopedics First Afffliated Hospital of Gannan Medical CollegeGanzhou 341000People’s Republic of China School of Mechanical and Automotive Engineering South China university of technologyGuangzhou 510641People’s Republic of China State Key Laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083People’s Republic of China Double Medical Technology Inc. Xiamen 361026People’s Republic of China

Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical ***-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated ***,the as-built part usually exhibits undesirable microstructure and unsatisfactory *** this work,WE43 parts were firstly fabricated by PBF-LB and then subjected to heat *** a high densification rate of 99.91%was achieved using suitable processes,the as-built parts exhibited anisotropic and layeredmicrostructure with heterogeneously precipitated Nd-rich *** heat treatment,fine and nano-scaled Mg24Y5particles were ***,theα-Mg grainsunderwent recrystallization and turned coarsened slightly,which effectively weakened thetexture intensity and reduced the *** a consequence,the yield strength and ultimate tensile strength were significantly improved to(250.2±3.5)MPa and(312±3.7)MPa,respectively,while the elongation was still maintained at a high level of 15.2%.Furthermore,the homogenized microstructure reduced the tendency of localized corrosion and favoredthe development of uniform passivation ***,the degradation rate of WE43 parts was decreased by an order of ***,in-vitro cell experiments proved their favorable biocompatibility.

关键词： laser-beam powder bed fusion WE43 alloys heat treatment mechanical performance biodegradation behavior

Metabolomic-based analysis reveals bile acid-mediated ovarian failure induced by low temperature in zebrafish

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Zoological Research 2024年第4期45卷 791-804页

作者： Wen-Hao Li zhi-qiang Li Meng-Di Bu Jia-Zhen Li Liang-Biao Chen Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Ministry of EducationCollege of Fisheries and Life SciencesShanghai Ocean UniversityShanghai 201306China Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and TechnologyQingdaoShandong 266237China International Research Center for Marine Biosciences Ministry of Science and TechnologyCollege of Fisheries and Life SciencesShanghai Ocean UniversityShanghai 201306China

As ectotherms, fish are highly sensitive to temperature fluctuations, which can profoundly impact their reproductive cycles. In this study, we investigated the fertility and histological characteristics of zebrafish(Danio rerio) ovaries exposed to a temperature gradient ranging from the thermopreferendum temperature of the species,27℃, to lower temperatures of 22℃, 20℃, and 13℃ over a period of two weeks. Comparative metabolomic(six biological replicates for each temperature) and transcriptomic(four biological replicates for each temperature) analyses were conducted under the four temperature conditions. Results indicated that lower temperatures inhibited oocyte development and differential metabolites were involved in steroid hormone production,antioxidant function, and lipid and protein *** reproductive hormones, increased proteolysis,and lipid degradation significantly impeded oocyte development and egg maturation. Notably, a significant increase in bile acid content was noted in the ovaries of the cold-treated fish, indicating that bile acids play a critical role in ovarian failure. Overall, these findings provide valuable insights into the mechanisms governing the reproductive response of fish to cold stress.

关键词： old stress Ovarian failure Metabolome Zebrafish

Harmful evaluation of heavy metals from soil layer to the groundwater: Take the Jilin Hunchun Basin as an example

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China Geology 2024年第1期7卷 116-124页

作者： Xiao-Dong Guo qiang Liu Hui-Rong Zhang Xu-Fei Shi Chuan-Yu Qin zhi-qiang Zhang Shenyang Geological Survey Center China Geological SurveyMinistry of Natural ResourcesShenyang 110034China Key Laboratory of Black Land Evolution and Ecological Effects Shenyang 110034China New Energy and Environment College Jilin UniversityChangchun 130026China Jilin Hydrogeological Survey Institute Changchun 130026China

The continuous enrichment of heavy metals in soils has caused potential harm to *** methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous *** on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is *** on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,*** results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending *** content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 *** harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or *** evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.

关键词： Soil heavy metals As+Hg+Cu+Pb+Zn+Ni+Cd Environmental capacity Groundwater Hazard degree Migration flux model Agricultural geological survey engineering Hunchun Basin Jilin Province

Comparative analysis of early and middle outcomes of the arterial switch operation in children with complete transposition of the great arteries with ventricular septal defect and severe pulmonary artery hypertension

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Chinese Medical Journal 2013年第11期126卷 2074-2078页

作者： LIU Cheng-hu SU Jun-wu LI zhi-qiang fan Xiang-ming CHEN Yan HE Yan LIUYing-long Department of Pediatric Cardiology Beijing An Zhen HospitalAffiliated to Capital Medical University Beijing Institute of HeartLung and Blood Vessel Diseases Beijing 100029 China

Background The best age for the arterial switch operation （ASO） in complete transposition of great arteries with ventricular septal defect is usually considered to be within six months. This is because of severe pulmonary arterial hypertension and pulmonary arterial obstructive pathological changes. There are few reports on ASO surgery in children older than three years old. Methods We studied 41 children, including 24 males and 17 females, from January 2010 to December 2011. They were divided into three groups by operation age; 15 patients were 〈1 year old, 13 were 1-3 years old, and 13 were 〉3 years old. Associated cardiac abnormalities included patent ductus arteriosus in six cases, atrial septal defect in five cases, and mitral regurgitation in two cases. All the patients had echocardiography before the operation. Seventeen patients underwent a coronary computed tomography examination and five patients underwent right heart catheterization. All ASO surgeries were performed under inhalation anesthesia and hypothermic cardiopulmonary bypass. Results Three operative deaths occurred. Two were in the 〈1 year old group, who died from severe postoperative low cardiac output. The other was two years old and died of postoperative multiple organ failure. There was no significant difference in postoperative mortality and the recent mid-term survival rate among the three groups. Thirty-eight cases were followed up for an average of 11.2 months, ranging 6-20 months. One seven years old patient died of acute diarrhea and electrolyte disturbance arrhythmia caused by food poisoning. Three patients more than three years old still had residual pulmonary arterial hypertension. Conclusion Children older than three years old can still undergo the ASO procedure, but residual pulmonary hypertension is present.

关键词： transposition of the great arteries arterial switch operation pulmonary arterial hypertension congenital heart disease

Data-driven mapping-relationship mining between hardness and mechanical properties of dual-phase titanium alloys via random forest and statistical analysis

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Rare Metals 2024年第2期43卷 829-841页

作者： Hai-Chao Gong Qun-Bo fan Hong-Mei Zhang Xing-Wang Cheng Wen-qiang Xie Kai Chen Lin Yang Jun-Jie Zhang Bing-qiang Wei Shun Xu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing100081China National Key Laboratory of Science and Technology on Materials Under Shock and Impact Beijing100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing401135China Department of Mechanical and Materials Engineering University of Nebraska-LincolnLincolnNE68588USA

In order to accelerate the research on the property optimization of titanium alloy based on high-throughput methods,it is necessary to reveal the relationship between hardness and other mechanical properties which is still *** this work,taking Ti20C alloy as research object,almost all the microstructure of dual-phase titanium alloys were covered by traversing over 100 heat treatment ***,massive experiments including microstructure characterization and performance test were conducted,obtaining 51,590 pieces of microstructure data and 3591 pieces of mechanical property ***,based on large-scale data-driven technology,the quantitative mapping relationship between hardness and other mechanical properties was deeply *** results of random forest models showed that the correlation between hardness(H)and Charpy impact energy(A_(k))(or elongation,A)was hardly dependent on the microstructure types,while the relationship between H and tensile strength(R_(m))(or yield strength,R_(p0.2))was highly dependent on microstructure ***,combined with statistical analysis,it was found that the relationship between H and Ak(or A)were negatively ***,the relationship between H and strength was positively linear for equiaxed microstructure,and strength was linked to d^(−1/2)(d,equivalent circle diameter)ofα-grains in the form of classical Hall–Petch formula;but for other microstructures,the relationships were ***,the above rules were nearly the same in the rolling direction and transverse ***,a"four-quadrant partition map"between H and R_(p0.2)/R_(m) was established as a versatile material-screening tool,which can provide guidance for on-demand selection of titanium alloys.

关键词： Dual-phase titanium alloy Data-driven Hardness Mapping relationship

Application of GNSS-PPP on Dynamic Deformation Monitoring of Offshore Platforms

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China Ocean Engineering 2024年第2期38卷 352-361页

作者： YU Li-na XIONG Kuan GAO Xi-feng LI zhi fan Li-long ZHANG Kai Institute of Ocean Energy and Intelligent Construction Tianjin University of TechnologyTianjin 300384China China Railway Construction Bridge Engineering Bureau Group Co.LTD Tianjin 300300China School of Civil Engineering Tianjin UniversityTianjin 300072China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong KongChina State Key Laboratory of Precision Blasting Jianghan UniversityWuhan 430056China

The real-time dynamic deformation monitoring of offshore platforms under environmental excitation is crucial to their safe *** Global Navigation Satellite System-Precise Point Positioning(GNSS-PPP)has been considered for this purpose,its monitoring accuracy is relatively ***,the influence of background noise on the dynamic monitoring accuracy of GNSS-PPP remains ***,it is imperative to further validate the feasibility of GNSS-PPP for deformation monitoring of offshore *** address these concerns,vibration table tests with different amplitudes and frequencies are *** results demonstrate that GNSS-PPP can effectively monitor horizontal vibration displacement as low as±30 mm,which is consistent with ***,the spectral characteristic of background noise in GNSS-PPP is similar to that of GNSS-RTK(Real Time Kinematic).Building on this observation,an improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN)has been proposed to de-noise the data and enhance the dynamic monitoring accuracy of *** monitoring application research is also undertaken,successfully extracting and analyzing the dynamic deformation of an offshore platform structure under environmental excitation using GNSS-PPP monitoring in conjunction with improved CEEMDAN *** comparing the de-noised dynamic deformation trajectories of the offshore platform during different periods,it is observed that the platform exhibits reversible alternating vibration responses under environmental excitation,with more pronounced displacement deformation in the direction of load *** research results confirm the feasibility and potential of GNSS-PPP for dynamic deformation monitoring of offshore platforms.

关键词： GNSS-PPP offshore platform dynamic deformation monitoring improved CEEMDAN de-noising

Printable oil-NiO_(X)hole transport layer enables efficient n-i-p perovskite solar cells with a high thermal stability

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Science China Chemistry 2024年第7期67卷 2335-2340页

作者： Yazhou Xu Zhaoyang Chu Hongyu Wang zhi Xing Baojin fan Xiaotian Hu Yiwang Chen College of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry(IPEC)/Film Energy Chemistry for Jiangxi Provincial Key Laboratory(FEC) Nanchang UniversityNanchang 330031China Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education Jiangxi Normal University Nanchang 330022China Peking University Yangtze Delta Institute of Optoelectronics Nantong 226010China

Currently,highly efficient n-i-p perovskite solar cells rely on an organic interface layer for high efficiency,especially 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)ami-no]-9,9′-spirobifluorene(spiro-OMeTAD),but the instability of organic materials in the photothermal field compromises device *** this study,we employ the oleic acid(YS)/oleamine(YA)end-sealing method to achieve uniform dispersion of NiO_(X)nanoparticles,effectively mitigating coagulation resulting from high local concentration and secondary motion ***,the conductivity of the hole transport layer and its energy level alignment with perovskite is enhanced by the additional 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone(F4TCNQ),leading to a remarkable improvement of open-circuit voltage and fill factor,thus the high efficiency of 25.17%and 24.36%on 0.1 and 1.01cm2,***,by realizing an all-inorganic interface layer,an initial efficiency exceeding 90%is maintained even after 2,800 h of heating at 85℃.

关键词： oil-NiO_(X) perovskite solar cells printing technology high efficiency thermal stability

A review of linear friction welding of Ni -based superalloys

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1382-1391页

作者： Xiawei Yang Tingxi Meng qiang Chu Yu Su Zhenguo Guo Rui Xu Wenlong fan Tiejun Ma Wenya Li State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding TechnologiesNorthwestern Polytechnical UniversityXi’an 710072China Xi’an Aerospace Engine Co.Ltd. Xi’an 710100China

Ni-based superalloys are one of the most important materials employed in high-temperature applications within the aerospace and nuclear energy industries and in gas turbines due to their excellent corrosion,radiation,fatigue resistance,and high-temperature *** friction welding(LFW)is a new joining technology with near-net-forming characteristics that can be used for the manu-facture and repair of a wide range of aerospace *** paper reviews published works on LFW of Ni-based superalloys with the aim of understanding the characteristics of frictional heat generation and extrusion deformation,microstructures,mechanical proper-ties,flash morphology,residual stresses,creep,and fatigue of Ni-based superalloy weldments produced with LFW to enable future optim-um utilization of the LFW process.

关键词： Ni-based superalloys linear friction welding microstructures mechanical properties flash morphology