检索结果-南通市图书馆

维普期刊数据库

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

在线全文

学校读者我要写书评

暂无评论

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 date.The in-situ mixing of various powders remains a significant challenge.This 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 materials.Firstly,a powder-mixing experimental platform was established;WC and 316L powders were selected for the mixing experiments.Secondly,scanning electron microscopy,energy dispersive spectroscopy,and image processing were used to visually evaluate the homogeneity and proportion of the in-situ mixed powder.Furthermore,powder-mixing simulations were conducted to determine the powder-mixing mechanism.In the simulations,a powder carrier gas flow field and particle mixing were employed.Finally,a WC/316L metal matrix composite sample was produced using laser-based DED to verify the application potential of the static mixer.It 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

The preface: Interplay of topological and magnetic orders in the Mn-Bi-Te family

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第2期11卷 6-7页

作者： Fu-chun Zhang Hai-Zhou Lu X.C.xie Kavli Institute for Theoretical Sciences University of Chinese Academy of Sciences Department of Physics Southern University of Science and Technology (SUSTech) International Center for Quantum Materials School of Physics Peking University

The discovery and synthesis of MnBi2Te4in 2013 initially garnered little attention [1]. Yet, the revelation of its topological properties in 2019 [2–6] sparked a surge of research into the MnBiTe family. These extensive studies are primarily driven by two objectives:the realization of a high-temperature quantum anomalous Hall effect （QAHE） and the exploration of exotic phases born from the interplay of topological and magnetic orders,

关键词：

Layer Hall effect induced by hidden Berry curvature in antiferromagnetic insulators

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第2期11卷 15-23页

作者： Rui Chen Hai-Peng Sun Mingqiang Gu chun-Bo Hua Qihang Liu Hai-Zhou Lu X.C.xie Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) International Quantum Academy Institute for Theoretical Physics and Astrophysics University of Würzburg School of Electronic and Information Engineering Hubei University of Science and Technology Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology Shenzhen Key Laboratory of Quantum Science and Engineering International Center for Quantum Materials School of PhysicsPeking University Collaborative Innovation Center of Quantum Matter CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences

The layer Hall effect describes electrons spontaneously deflected to opposite sides at different layers, which has been experimentally reported in the MnBi2Te4thin films under perpendicular electric fields. Here, we reveal a universal origin of the layer Hall effect in terms of the so-called hidden Berry curvature, as well as material design principles. Hence, it gives rise to zero Berry curvature in momentum space but non-zero layer-locked hidden Berry curvature in real space. We show that, compared to that of a trivial insulator, the layer Hall effect is significantly enhanced in antiferromagnetic topological insulators. Our universal picture provides a paradigm for revealing the hidden physics as a result of the interplay between the global and local symmetries, and can be generalized in various scenarios.

关键词： layerHall effect hidden Berry curvature antiferromagnetic insulator axion insulator, quantum transport

Association between inflammatory bowel disease and all-cause dementia:A two-sample Mendelian randomization study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Psychiatry 2024年第1期14卷 15-25页

作者： Ou-Lan Liao Si-Yuan xie Jun Ye Qin Du Guo-chun Lou Department of Gastroenterology The Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009Zhejiang ProvinceChina Department of Gastroenterology The Fourth Affiliated HospitalZhejiang University School of MedicineYiwu 322000Zhejiang ProvinceChina

BACKGROUND Numerous observational studies have documented a correlation between inflammatory bowel disease(IBD)and an increased risk of dementia.However,the causality of their associations remains elusive.AIM To assess the causal relationship between IBD and the occurrence of all-cause dementia using the two-sample Mendelian randomization(MR)method.METHODS Genetic variants extracted from the large genome-wide association study(GWAS)for IBD(the International IBD Genetics Consortium,n=34652)were used to identify the causal link between IBD and dementia(FinnGen,n=306102).The results of the study were validated via another IBD GWAS(United Kingdom Biobank,n=463372).Moreover,MR egger intercept,MR pleiotropy residual sum and outlier,and Cochran's Q test were employed to evaluate pleiotropy and heterogeneity.Finally,multiple MR methods were performed to estimate the effects of genetically predicted IBD on dementia,with the inverse variance weighted approach adopted as the primary analysis.RESULTS The results of the pleiotropy and heterogeneity tests revealed an absence of significant pleiotropic effects or heterogeneity across all genetic variants in outcome GWAS.No evidence of a causal effect between IBD and the risk of dementia was identified in the inverse variance weighted[odds ratio(OR)=0.980,95%CI:0.942-1.020,P value=0.325],weighted median(OR=0.964,95%CI:0.914-1.017,P value=0.180),and MR-Egger(OR=0.963,95%CI:0.867-1.070,P value=0.492)approaches.Consistent results were observed in validation analyses.Reverse MR analysis also showed no effect of dementia on the development of IBD.Furthermore,MR analysis suggested that IBD and its subtypes did not causally affect allcause dementia and its four subtypes,including dementia in Alzheimer's disease,vascular dementia,dementia in other diseases classified elsewhere,and unspecified dementia.CONCLUSION Taken together,our MR study signaled that IBD and its subentities were not genetically associated with all-cause dementia or its subtypes.Further large prospective studies are w

关键词： Inflammatory bowel disease All-cause dementia Mendelian randomization Causal effect Risk factor©The

Brain abscess from oral microbiota approached by metagenomic next-generation sequencing: A case report and review of literature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第3期12卷 616-622页

作者： Xue-Min Zhu chun-Xia Dong Lei xie Hao-Xin Liu Huai-Qiang Hu School of Clinical Medicine Weifang Medical UniversityWeifang 261053Shandong ProvinceChina Department of Neurology the 960th Hospital of People′s Liberation ArmyJinan 250031Shandong ProvinceChina

BACKGROUND Brain abscess is a serious and potentially fatal disease caused primarily by microbial infection.Although progress has been made in the diagnosis and treatment of brain abscesses,the diagnostic timeliness of pathogens needs to be improved.CASE SUMMARY We report the case of a 54-year-old male with a brain abscess caused by oral bacteria.The patient recovered well after receiving a combination of metagenomic next-generation sequencing(mNGS)-assisted guided medication and surgery.CONCLUSION Therefore,mNGS may be widely applied to identify the pathogenic microor-ganisms of brain abscesses and guide precision medicine.

关键词： Brain abscess Metagenomic next-generation sequencing Periodontitis Oral bacteria Precision medicine Case report

Artificial neural network-based method for discriminating Compton scattering events in high-purity germaniumγ-ray spectrometer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第2期35卷 64-84页

作者： chun-di Fan Guo-Qiang Zeng Hao-Wen Deng Lei Yan Jian Yang Chuan-Hao Hu Song Qing Yang Hou College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059China

To detect radioactive substances with low activity levels,an anticoincidence detector and a high-purity germanium(HPGe)detector are typically used simultaneously to suppress Compton scattering background,thereby resulting in an extremely low detection limit and improving the measurement accuracy.However,the complex and expensive hardware required does not facilitate the application or promotion of this method.Thus,a method is proposed in this study to discriminate the digital waveform of pulse signals output using an HPGe detector,whereby Compton scattering background is suppressed and a low minimum detectable activity(MDA)is achieved without using an expensive and complex anticoincidence detector and device.The electric-field-strength and energy-deposition distributions of the detector are simulated to determine the relationship between pulse shape and energy-deposition location,as well as the characteristics of energy-deposition distributions for fulland partial-energy deposition events.This relationship is used to develop a pulse-shape-discrimination algorithm based on an artificial neural network for pulse-feature identification.To accurately determine the relationship between the deposited energy of gamma(γ)rays in the detector and the deposition location,we extract four shape parameters from the pulse signals output by the detector.Machine learning is used to input the four shape parameters into the detector.Subsequently,the pulse signals are identified and classified to discriminate between partial-and full-energy deposition events.Some partial-energy deposition events are removed to suppress Compton scattering.The proposed method effectively decreases the MDA of an HPGeγ-energy dispersive spectrometer.Test results show that the Compton suppression factors for energy spectra obtained from measurements on ^(152)Eu,^(137)Cs,and ^(60)Co radioactive sources are 1.13(344 keV),1.11(662 keV),and 1.08(1332 keV),respectively,and that the corresponding MDAs are 1.4%,5.3%,and 21.6%lower,respectively.

关键词： High-purity germaniumγ-ray spectrometer Pulse-shape discrimination Compton scattering Artificial neural network Minimum detectable activity

维普期刊数据库

Insight study of rare earth elements in PM_(2.5)during five years in a Chinese inland city:Composition

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 439-449页

作者： Yi-Wen Shen Chang-Xian Zhao Hao Zhao Shuo-Fei Dong Qi Guo Jiao-Jiao xie Mei-Ling Lv chun-Gang Yuan Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control Department ofEnvironmental Science&EngineeringNorth China Electric Power UniversityBaoding 071000China MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China Agilent Technologies Co.Ltd.(China) Beijing 100102China

The booming development of rare earth industry and the extensive utilization of its products accompanied by urban development have led to the accelerated accumulation of rare earth elements(REEs)as emerging pollutants in atmospheric environment.In this study,the variation of REEs in PM_(2.5)with urban(a non-mining city)transformation was investigated through five consecutive years of sample collection.The compositional variability and provenance contribution of REEs in PM_(2.5)were characterized,and the REEs exposure risks of children and adults via inhalation,ingestion and dermal absorption were also evaluated.The results showed an increase in the total REEs concentration from 46.46±35.16 mg/kg(2017)to 81.22±38.98 mg/kg(2021)over the five-year period,with Ce and La making the largest contribution.The actual increment of industrial and traffic emission source among the three pollution sources was 1.34 ng/m^(3).Coal combustion source displayed a downward trend.Ingestion was the main exposure pathway for REEs in PM_(2.5)for both children and adults.Ce contributed the most to the total intake of REEs in PM_(2.5)among the population,followed by La and Nd.The exposure risks of REEs in PM_(2.5)in the region were relatively low,but the trend of change was of great concern.It was strongly recommended to strengthen the concern about traffic-related non-exhaust emissions of particulate matter.

关键词： Rare earth elements Exposure risks Pollution sources Traffic-related non-exhaust emissions

维普期刊数据库

A Sampling-Based Method to Estimate the Volume of Solution Space for Linear Arithmetic Constraints

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年

作者： xie Yan-Feng YUAN chun-Ming JING Rui-Juan KLMM Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences School of Mathematical Sciences Jiangsu University

The linear arithmetic constraints play important roles in many research fields. Estimating the volume of their solution spaces has specific applications, such as programming verification, linear programming, polyhedral optimization, and so on. In this paper, the authors provide an efficient estimation for the volume of the solution space for linear arithmetic constraints. This method sums up the estimations for volumes of oblique cones centered along randomly generated rays. The error analysis is provided to improve the accuracy.

关键词：

The role of innate immunity in diabetic nephropathy and their therapeutic consequences

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2024年第1期14卷 39-51页

作者： Min Yang chun Zhang Department of Nephrology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China

diabetic nephropathy (DN) is an enduring condition that leads to inflammation and affects a substantial number of individuals with diabetes worldwide. A gradual reduction in glomerular filtration and emergence of proteins in the urine are typical aspects of DN, ultimately resulting in renal failure. Mounting evidence suggests that immunological and inflammatory factors are crucial for the development of DN. Therefore, the activation of innate immunity by resident renal and immune cells is critical for initiating and perpetuating inflammation. Toll-like receptors (TLRs) are an important group of receptors that identify patterns and activate immune responses and inflammation. Meanwhile, inflammatory responses in the liver, pancreatic islets, and kidneys involve inflammasomes and chemokines that generate pro-inflammatory cytokines. Moreover, the activation of the complement cascade can be triggered by glycated proteins. This review highlights recent findings elucidating how the innate immune system contributes to tissue fibrosis and organ dysfunction, ultimately leading to renal failure. This review also discusses innovative approaches that can be utilized to modulate the innate immune responses in DN for therapeutic purposes.

关键词： Innate immunity diabetic nephropathy Inflammation Toll-like receptor Inflammasomes