检索结果-南通市图书馆

Rapid in situ alloying of CoCrFeMnNi high-entropy alloy from elemental feedstock toward high-throughput synthesis via laser powder bed fusion

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2023年第1期18卷 131-145页

作者： Bowen WANG bingheng lu Lijuan ZHANG Jianxun ZHANG Bobo LI Qianyu JI Peng luO Qian LIU School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049China National Innovation Institute of Additive Manufacturing Xi’an 710300China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China Institute of Materials China Academy of Engineering PhysicsMianyang 621908China

High-entropy alloys(HEAs)are considered alternatives to traditional structural materials because of their superior mechanical,physical,and chemical properties.However,alloy composition combinations are too numerous to explore.Finding a rapid synthesis method to accelerate the development of HEA bulks is imperative.Existing in situ synthesis methods based on additive manufacturing are insufficient for efficiently controlling the uniformity and accuracy of components.In this work,laser powder bed fusion(L-PBF)is adopted for the in situ synthesis of equiatomic CoCrFeMnNi HEA from elemental powder mixtures.High composition accuracy is achieved in parallel with ensuring internal density.The L-PBF-based process parameters are optimized;and two different methods,namely,a multi-melting process and homogenization heat treatment,are adopted to address the problem of incompletely melted Cr particles in the single-melted samples.X-ray diffraction indicates that HEA microstructure can be obtained from elemental powders via L-PBF.In the triple-melted samples,a strong crystallographic texture can be observed through electron backscatter diffraction,with a maximum polar density of 9.92 and a high ultimate tensile strength(UTS)of(735.3±14.1)MPa.The homogenization heat-treated samples appear more like coarse equiaxed grains,with a UTS of(650.8±16.1)MPa and an elongation of(40.2%±1.3%).Cellular substructures are also observed in the triple-melted samples,but not in the homogenization heat-treated samples.The differences in mechanical properties primarily originate from the changes in strengthening mechanism.The even and flat fractographic morphologies of the homogenization heat-treated samples represent a more uniform internal microstructure that is different from the complex morphologies of the triple-melted samples.Relative to the multi-melted samples,the homogenization heat-treated samples exhibit better processability,with a smaller composition deviation,i.e.,≤0.32 at.%.The two methods presented in this study are expected to ha

关键词： laser powder bed fusion(L-PBF) in situ alloying high-entropy alloys heat treatment rapid synthesis

Porous bio-high entropy alloy scaffolds fabricated by direct ink writing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第26期157卷 21-29页

作者： Guangbin Zhao Xiaoxi Shao Qingxian Zhang Yanlong Wu Yaning Wang Xu Chen Hang Tian Yaxiong Liu Yanpu Liu bingheng lu State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710054China State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Clinical Research Center for Oral Diseases Department of Oral and Maxillofacial SurgerySchool of StomatologyThe Fourth Military Medical UniversityXi’an 710032China School of Mechatronic Engineering and Automation Foshan UniversityFoshan 528000China Ji Hua Laboratory Foshan 528200China College of Mechanical Engineering Xi’an University of Science and TechnologyXi’an 710054China

Porous tantalum-titanium-niobium-zirconium(Ta-Ti-Nb-Zr)bio-high entropy alloy(bioHEA)scaffolds are fabricated using direct ink writing 3D printing technology in this study.A composite ink is prepared using four metal powders as raw materials:Ta,Ti,Nb and Zr.Ink extrusion is used to build 3D scaf-folds with interconnected porous structures at room temperature,which are then sintered in a vacuum environment.The interdiffusion of metal elements yields porous bioHEA scaffolds with a body-centered cubic(BCC)structure.The fabricated scaffolds have uniform compositions with a significant alloying ef-fect and good biocompatibility.The scaffolds have a compressive strength of 70.08-149.95 MPa and an elastic modulus of 0.18-0.64 GPa,indicating that the mechanical properties can be controlled over a wide range.The scaffolds have a compressive strength close to that of human cortical bone and thus meet the requirements for porous structure characteristics and biological and mechanical properties of orthopedic implants.

关键词： Direct ink writing Bio-high entropy alloy Porous scaffolds Sintering Biocompatibility Orthopedic applications

金属增材制造质量控制及复合制造技术研究现状

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

材料导报 2024年第9期38卷 178-185页

作者：刘倩卢秉恒华北理工大学冶金与能源学院河北唐山063210 西安交通大学机械工程学院西安710049 国家增材制造创新中心西安710117

相比传统制造工艺,增材制造能够实现复杂结构金属部件的近净成形。然而,增材制造具有冷却速度快、热梯度大、非平衡凝固与往复热循环历史等特点,容易存在孔洞、残余拉应力、各向异性等缺陷,极大限制增材制造的进一步应用。复合增材制造... 详细信息

相比传统制造工艺,增材制造能够实现复杂结构金属部件的近净成形。然而,增材制造具有冷却速度快、热梯度大、非平衡凝固与往复热循环历史等特点,容易存在孔洞、残余拉应力、各向异性等缺陷,极大限制增材制造的进一步应用。复合增材制造技术是将传统制造方法与增材制造有机结合,充分发挥传统制造工艺在性能调控与尺寸精度等方面的优势,抑制单纯增材制造引起的各类缺陷,获得高质量、无缺陷的增材制造部件。本文首先揭示增材制造工艺缺陷的形成机理,明确工艺参数优化方法在缺陷改善方面的局限性,进而阐明复合增材制造的内涵,综述近年来增材制造与轧制、激光冲击强化、热等静压、热处理等复合制造技术的研究现状与工艺原理,探讨复合增材制造技术对不同缺陷的适用性,并对增材制造未来发展方向进行了展望。

关键词：复合增材制造塑性变形激光冲击各向异性残余应力

Collective Molecular Machines: Multidimensionality and Reconfigurability

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第8期16卷 309-340页

作者： Bin Wang Yuan lu Department of Chemical Engineering Tsinghua UniversityBeijing 100084People’s Republic of China Key Laboratory of Industrial Biocatalysis Ministry of EducationTsinghua UniversityBeijing 100084People’s Republic of China

Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical work.During the last 60 years,designing molecular structures capable of generating unidirectional mechanical motion at the nanoscale has been the topic of intense research.Effective progress has been made,attributed to advances in various fields such as supramolecular chemistry,biology and nanotechnology,and informatics.However,individual molecular machines are only capable of producing nanometer work and generally have only a single functionality.In order to address these problems,collective behaviors realized by integrating several or more of these individual mechanical units in space and time have become a new paradigm.In this review,we comprehensively discuss recent developments in the collective behaviors of molecular machines.In particular,collective behavior is divided into two paradigms.One is the appropriate integration of molecular machines to efficiently amplify molecular motions and deformations to construct novel functional materials.The other is the construction of swarming modes at the supramolecular level to perform nanoscale or microscale operations.We discuss design strategies for both modes and focus on the modulation of features and properties.Subsequently,in order to address existing challenges,the idea of transferring experience gained in the field of micro/nano robotics is presented,offering prospects for future developments in the collective behavior of molecular machines.

关键词： Molecular machines Collective control Collective behaviors DNA Biomolecular motors

Soil inorganic amendments produce safe rice by reducing the transfer of Cd and increasing key amino acids in brown rice

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 121-132页

作者： Fanyi Kong Shenggao lu Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment Key Laboratory of Environmental Remediation and Ecosystem HealthMinistry of EducationCollege of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China

The digestibility of cadmium(Cd)in brown rice is directly related to amino acid metabolism in rice and human health.In our field study,three kinds of alkaline calcium-rich soil inorganic amendments(SIAs)at three dosages were applied to produce safe rice and improve the quality of rice in Cd-contaminated paddy.With the increased application of SIA,Cd content in iron plaque on rice root significantly increased,the transfer of Cd from rice root to grain significantly decreased,and then Cd content in brown rice decreased synchronously.The vitro digestibility of Cd in brown rice was estimated by a physiologically based extraction test.Results showed that more than 70%of Cd in brown rice could be digested by simulated gastrointestinal juice.Based on the total and digestible Cd contents in brown rice to evaluate the health risk,the application of 2.25 ton SIA/ha could produce safe rice in acidic slightly Cd-contaminated paddy soils.The amino acids(AAs)in brown rice were determined by high-performance liquid chromatography.The contents of 5 key AAs(KAAs)that actively respond to environmental changes increased significantly with the increased application of SIA.The structural equation model indicated that KAAs could be affected by the Cd translocation capacity from rice root to grain,and consequently altered the ratio of indigestible Cd in brown rice.The formation of indigestible KAAs-Cd complexes by combining KAAs(phenylalanine,leucine,histidine,glutamine,and asparagine)with Cd in brown rice could be considered a potential mechanism for reducing the digestibility of Cd.

关键词： Cadmium digestibility Soil inorganic amendments Safe rice Amino acid Priming effect Health risk

Light touch in quantum:an interview with Prof.Serge Haroche

在线全文

学校读者我要写书评

暂无评论

Advanced Photonics 2024年第1期6卷 10-16页

作者： Chao-Yang lu CAS Centre for Excellence in Quantum Information and Quantum Physics HefeiChina NYU Shanghai NYU-ECNU Institute of PhysicsShanghaiChina University of Science and Technology of China Department of Modern PhysicsShanghaiChina

lu:Hello,Prof.Haroche,nice to see you again!Let us start the interview.In 2012,you and David Wineland won the Nobel Prize in Physics.Can you describe your work in simple terms to a general audience?And can you tell us how you were originally interested in this field and got into this study?Haroche:Maybe I should start with the second part of the question.I got interested in atomic physics when I was a student atÉcole Normale Supérieure(ENS)in Paris in the 1960s.

关键词： quantum interview Serge

Research center of biomanufacturing in Xi'an Jiaotong University

在线全文

学校读者我要写书评

暂无评论

Bio-Design and Manufacturing 2018年第4期1卷 280-288页

作者： Ling Wang Dichen Li Jiankang He bingheng lu State Key Lab for Manufacturing System Engineering Xi'an Jiaotong UniversityXi'an 710054China School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710049China

Xi'an Jiaotong University (XJTU)has carded out the research of additive manufacturing (AM)since 1993,who is one of the earliest institutes majoring in AM.After 20years of effort,XJTU has made great progress on the additive manufacturing of polymer,metals,ceramics,composite materials and intelligent materials.XJTU has established a research team that features the engineering application of rapid manufacturing system.

关键词： Xi'an Jiaotong University

Expression of cyclin-dependent kinase 9 is positively correlated with the autophagy level in colon cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第2期16卷 314-330页

作者： Lei Zheng Jia lu Da-lu Kong Department of Colorectal Cancer Surgery National Clinical Research Center for CancerKey Laboratory of Cancer Immunology and Biotherapy of TianjinTianjin Key Laboratory of Digestive CancerKey Laboratory of Cancer Prevention and Therapy of TianjinTianjin’s Clinical Research Center for CancerTianjin Medical University Cancer Institute and HospitalTianjin 300060China Department of Infection Management National Clinical Research Center for CancerKey Laboratory of Cancer Immunology and Biotherapy of TianjinTianjin Key Laboratory of Digestive CancerKey Laboratory of Cancer Prevention and Therapy of TianjinTianjin’s Clinical Research Center for CancerTianjin Medical University Cancer Institute and HospitalTianjin 300060China

BACKGROUND Cyclin-dependent kinase 9(CDK9)expression and autophagy in colorectal cancer(CRC)tissues has not been widely studied.CDK9,a key regulator of transcription,may influence the occurrence and progression of CRC.The expression of auto-phagy-related genes BECN1 and drug resistance factor ABCG2 may also play a role in CRC.Under normal physiological conditions,autophagy can inhibit tumorigenesis,but once a tumor forms,autophagy may promote tumor growth.Therefore,understanding the relationship between autophagy and cancer,partic-ularly how autophagy promotes tumor growth after its formation,is a key motivation for this research.AIM To investigate the relationship between CDK9 expression and autophagy in CRC,assess differences in autophagy between left and right colon cancer,and analyze the associations of autophagy-related genes with clinical features and prognosis.METHODS We collected tumor tissues and paracarcinoma tissues from colon cancer patients with liver metastasis to observe the level of autophagy in tissues with high levels of CDK9 and low levels of CDK9.We also collected primary tissue from left and right colon cancer patients with liver metastasis to compare the autophagy levels and the expression of BECN1 and ABCG2 in the tumor and paracarcinoma tissues.RESULTS The incidence of autophagy and the expression of BECN1 and ABCG2 were different in left and right colon cancer,and autophagy might be involved in the occurrence of chemotherapy resistance.Further analysis of the rela-tionship between the expression of autophagy-related genes CDK9,ABCG2,and BECN1 and the clinical features and prognosis of colorectal cancer showed that the high expression of CDK9 indicated a poor prognosis in colorectal cancer.CONCluSION This study laid the foundation for further research on the combination of CDK9 inhibitors and autophagy inhibitors in the treatment of patients with CRC.

关键词： Autophagy Tumorigenesis Tumor tissue Paracarcinoma tissue Expression Left/right colon cancer

Comprehensive study on the spatial distribution of heavy metals and their environmental risks in high-sulfur coal gangue dumps in China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 486-497页

作者： Yingbo Dong Huan lu Hai Lin School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants Beijing 100083China

The accumulation of coal gangue(CG)from coal mining is an important source of heavy metals(HMs)in soil.Its spatial distribution and environment risk assessment are extremely important for the management and remediation of HMs.Eighty soil samples were collected from the high-sulfur CG site in northern China and analyzed for six HMs.The results showed that the soil was heavily contaminated by Mn,Cr and Ni based on the Nemerow index,and posed seriously ecological risk depended on the geo-accumulation index,potential ecological risk index and risk assessment code.The semi-variogram model and ordinary kriging interpolation accurately portrayed the spatial distribution of HMs.Fe,Mn,and Cr were distributed by band diffusion,Ni was distributed by core,the distribution of Cu had obvious patchiness and Zn was more uniform.The spatial autocorrelation indicated that all HMs had strong spatial heterogeneity.The BCR sequential extraction was employed to qualify the geochemical fractions of HMs.The data indicated that Fe and Cr were dominated by residual fraction;Cu,Ni and Zn were dominated by reducible and oxidizable fractions;Mn was dominated by reducible and acid-extractable(25.38%-44.67%)fractions.Pearson correlation analysis showed that pH was the main control factor affecting the non-residue fractions of HMs.Therefore,acid production from high sulfur CG reduced soil pH by 2-3,which indirectly promoted the activity of HMs.Finally,the conceptual model of HMs contamination at the CG site was proposed,which can be useful for the development of ecological remediation strategies.

关键词： High-sulfur coal gangue Soil contamination Heavy metals Spatial distribution Geochemical fractions Risk assessment