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Study of relationship between motion of mechanisms in gas operated weapon and its shock absorber

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Defence Technology（防务技术） 2024年第3期33卷 42-54页

作者： Jiri Balla Roman Vitek Dung Nguyen van Zbynek Krist Hung Nguyen van Department of Weapons and Ammunition University of Defence BrnoCzech Republic Department of Weapons Le Quy Don Technical UniversityHanoiViet Nam Department of Design and Special Engineering Alexander Dubcek University of TrencinSlovakia

The article deals with the motion of the breech block carrier and the weapon casing of an automatic weapon mounted on a flexible carriage and the base of the *** works,which did not consider the dynamic properties of the base of the weapon,did not allow to reconcile the calculated and experimental results of the weapon casing displacement when shooting from firing *** the analysis of the motion of individual parts,the methods of mathematical modelling and firing experiments using a high-speed camera were *** show the best accord with experiment when modelling the system with 4 degrees of *** oscillation of the system regarding the movement of the breech block carrier and the weapon casing was investigated under changed conditions of rate of fire,the use of a muzzle brake and different types of shock *** velocities and displacements of the weapon casing and the breech block carrier at different values of the impulse of the gases to the breech block carrier were determined.

关键词： Shock absorber Gas-operated weapon Force-impulse diagram Recoil system Breech block carrier

A new perspective on intervertebral disc calcification—from bench to bedside

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Bone Research 2024年第1期12卷 50-61页

作者： Emanuel J.Novais Rajkishen Narayanan Jose A.Canseco Koen van de Wetering Christopher K.Kepler Alan S.Hilibrand alexander R.Vaccaro Makarand V.Risbud Department of Orthopaedic Surgery Sidney Kimmel Medical CollegeThomas Jefferson UniversityPhiladelphiaPAUSA Unidade Local de Saúde do Litoral Alentejano Orthopedic DepartmentSantiago do CacémPortugal Rothman Orthopedic Institute at Thomas Jefferson University PhiladelphiaPAUSA

Disc degeneration primarily contributes to chronic low back and neck ***,there is an urgent need to understand the spectrum of disc degeneration phenotypes such as fibrosis,ectopic calcification,herniation,or mixed *** these phenotypes,disc calcification is the least *** calcification,by definition,is the pathological mineralization of soft tissues,widely studied in the context of conditions that afflict vasculature,skin,and ***,disc calcification is associated with poor surgical outcomes and back pain refractory to conservative *** is frequently seen as a consequence of disc aging and progressive degeneration but exhibits unique molecular and morphological characteristics:hypertrophic chondrocyte-like cell differentiation;TNAP,ENPP1,and ANK upregulation;cell death;altered Pi and PPi homeostasis;and local *** studies in mouse models have provided a better understanding of the mechanisms underlying this *** is essential to recognize that the presentation and nature of mineralization differ between AF,NP,and EP ***,the combination of anatomic location,genetics,and environmental stressors,such as aging or trauma,govern the predisposition to ***,the systemic regulation of calcium and Pi metabolism is less important than the local activity of PPi modulated by the ANK-ENPP1 axis,along with disc cell death and differentiation *** there is limited understanding of this phenotype,understanding the molecular pathways governing local intervertebral disc calcification may lead to developing disease-modifying drugs and better clinical management of degeneration-related pathologies.

关键词： degeneration metabolism intervertebral

Modular-integrative modeling: a new framework for building brain models that blend biological realism and functional performance

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National Science Review 2024年第5期11卷 13-16页

作者： Mario Senden Sacha J.van Albada Giovanni Pezzulo Egidio Falotico Ibrahim Hashim alexander Kroner Anno C.Kurth Pablo Lanillos Vaishnavi Narayanan Cyriel Pennartz Mihai A.Petrovici Lea Steffen Tonio Weidler Rainer Goebel Department of Cognitive Neuroscience Maastricht University Maastricht Brain Imaging Centre Maastricht University Institute of Neuroscience and Medicine(INM-6) and Institute for Advanced Simulation(IAS-6) and JARA-Institut Brain Structure-Function Relationships(INM-10) Jülich Research Center Institute of Zoology University of Cologne Institute of Cognitive Sciences and Technologies The Bio Robotics Institute Scuola Superiore Sant'Anna RWTH Aachen University Donders Institute for Brain Cognition and BehaviorRadboud University Cognitive and Systems Neuroscience Group Swammerdam Institute for Life Sciences University of Amsterdam Department of Physiology University of Bern FZI Research Center of Information Technology

To cope with the immense complexity of the brain, neuroscientific research often focuses on isolated brain structures or circumscribed perceptual, cognitive or motor functions [1]. This reductionist approach overlooks the intricate and multifaceted interplay among various structural and functional *** instance, even simple movements require the coordinated activation of numerous neuronal populations across multiple brain regions [2].

关键词： WORLD SURVEY PROJECTS

Lateral femoral neck stress fractures: A case report

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World Journal of Orthopedics 2024年第9期15卷 891-901页

作者： Christiaan AJ Oudmaijer Nuno R Paulino Pereira David Visser alexander M Wakker Wout S Veltman Robbart van Linschoten Department of Surgery Division of Hepatobiliary and Transplantation SurgeryErasmus MC Transplant InstituteRotterdam 3015 GDZuid-HollandNetherlands Princess Maxima Center for Pediatric Oncology Utrecht 3584 CSNetherlands Orthopaedics and Sports Medicine Erasmus MCErasmus University Medical Center RotterdamRotterdam 3015 GDZuid-HollandNetherlands Department of Surgery Division of Trauma SurgeryErasmus MCErasmus University Medical Center RotterdamRotterdam 3015 GDZuid-HollandNetherlands

BACKGROUND Sport-induced injuries particularly affect young,healthy,and active ***,a popular and accessible sport,can cause a wide range of injuries,including stress *** fractures can occur during high-intensity training or competitions,especially among well-trained amateurs and professional *** diagnosis can be complicated by the typically young age,unremarkable medical history,and vital condition of the *** fractures present insidiously,and this is specifically the case with stress fractures of the femoral *** intervention is crucial to prevent progressive displacement,as this can damage the blood supply to the femoral *** SUMMARY A 30-year-old male runner presented to our outpatient clinic with persistent pain 3 weeks after running a marathon.X-ray showed a complete lateral fracture of the left femoral neck,which was treated surgically with a dynamic hip *** It is essential for healthcare providers to be vigilant for the subtle symptoms of stress fractures to ensure timely *** recognition prevents com-plication and leads to a better prognosis.

关键词： Stress fractures Atypical Femoral Neck Marathon Diagnosis Case report

Genome-wide Studies Reveal Genetic Risk Factors for Hepatic Fat Content

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Genomics, Proteomics & Bioinformatics 2024年第2期22卷 57-68页

作者： Yanni Li Eline H.van den Berg alexander Kurilshikov Dasha V.Zhernakova Ranko Gacesa Shixian Hu Esteban A.Lopera-Maya Alexandra Zhernakova Lifelines Cohort Study Vincent E.de Meijer Serena Sanna Robin P.F.Dullaart Hans Blokzijl Eleonora A.M.Festen Jingyuan Fu Rinse K.Weersma Department of Gastroenterology and Hepatology University of GroningenUniversity Medical Center GroningenGroningen 9713 GZThe Netherlands Department of Genetics University of GroningenUniversity Medical Center GroningenGroningen 9713 GZThe Netherlands Department of Gastroenterology and Hepatology Tianjin Medical University General HospitalTianjin Medical UniversityTianjin 300052China Laboratory of Genomic Diversity Center for Computer TechnologiesITMO UniversitySaint Petersburg 199034Russia Institute of Precision Medicine the First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Department of Surgery Section of Hepatobiliary Surgery and Liver TransplantationUniversity of GroningenUniversity Medical Center GroningenGroningen 9713 GZThe Netherlands Department of Endocrinology University of GroningenUniversity Medical Center GroningenGroningen 9713 GZThe Netherlands Department of Pediatrics University of GroningenUniversity Medical Center GroningenGroningen 9713 GZThe Netherlands 不详

Genetic susceptibility to metabolic associated fatty liver disease(MAFLD)is complex and poorly *** characterization of the genetic background of hepatic fat content would provide insights into disease etiology and causality of risk *** performed genome-wide association study(GWAS)on two noninvasive definitions of hepatic fat content:magnetic resonance imaging proton density fat fraction(MRI-PDFF)in 16,050 participants and fatty liver index(FLI)in 388,701 participants from the United Kingdom(UK)Biobank(UKBB).Heritability,genetic overlap,and similarity between hepatic fat content phenotypes were analyzed,and replicated in 10,398 participants from the University Medical Center Groningen(UMCG)Genetics Lifelines Initiative(UGLI).Meta-analysis of GWASs of MRI-PDFF in UKBB revealed five statistically significant loci,including two novel genomic loci harboring CREB3L1(rs72910057-T,P=5.40E−09)and GCM1(rs1491489378-T,P=3.16E−09),respectively,as well as three previously reported loci:PNPLA3,TM6SF2,and *** of FLI in UKBB identified 196 genome-wide significant loci,of which 49 were replicated in UGLI,with top signals in ZPR1(P=3.35E−13)and FTO(P=2.11E−09).Statistically significant genetic correlation(rg)between MRI-PDFF(UKBB)and FLI(UGLI)GWAS results was found(rg=0.5276,P=1.45E−03).Novel MRI-PDFF genetic signals(CREB3L1 and GCM1)were replicated in the FLI *** identified two novel genes for MRI-PDFF and 49 replicable loci for *** a difference in hepatic fat content assessment between MRI-PDFF and FLI,a substantial similar genetic architecture was *** is identified as an easy and reliable approach to study hepatic fat content at the population level.

关键词： Hepatic fat content MAFLD Genome-wide association study Fatty liver index Magnetic resonance imaging proton density fat fraction

饮用水砷暴露与QT间期延长:砷对健康影响的纵向研究结果

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环境与职业医学 2013年第7期30卷 550-550页

作者： Yu Chen Fen Wu Faruque Parvez Alauddin Ahmed Mahbub Eunus Tyler R.McClintock Tazul Islam Patwary Tariqul Islam Anajan Kumar Ghosal Shahidul Islam Rabiul Hasan Diane Levy Golam Sarwar Vesna Slavkovich alexander van geen Joseph H.Graziano Habibul Ahsan

[背景]饮用水砷暴露与心脏疾病相关联,然而内在的机制尚不明确。[目的]评估饮用水砷暴露史与心率校正的QT(QTc)、PR和QRS间期延长之间的关联。[方法]从砷对健康影响的纵向研究中选择1715名基线入组的参加者进行研究。评估2005—2010年间... 详细信息

[背景]饮用水砷暴露与心脏疾病相关联,然而内在的机制尚不明确。[目的]评估饮用水砷暴露史与心率校正的QT(QTc)、PR和QRS间期延长之间的关联。[方法]从砷对健康影响的纵向研究中选择1715名基线入组的参加者进行研究。评估2005—2010年间,井水中的砷暴露和尿液样本与心电图(ECG)参数的关联,自基线开始平均跟踪了5.9年。[结果]QTc延长的定义为男性QTc≥450ms,女性≥460ms。井水中砷每增加1-SD(108.7μg/L),QTc延长的调整比值比(OR)为1.17(95%CI:1.01～1.35)。正相关仅限于女性,基线时井水和尿液中的砷每增加1-SD,女性调整后ORs分别比为1.24(95%CI:1.05～1.47)和1.24(95%CI:1.01～1.53);与之相比,男性调整后ORs分别为0.99(95%CI:0.73～1.33)和0.86(95%CI:0.49～1.51)。基线时井水砷或尿砷与女性或男性的PR或QRS间期延长之间无明显的关联。[结论]长期饮用水砷暴露(平均95μg/L,全距为0.1～790μg/L)与女性之后的QT间期延长相关联。在今后的纵向研究中,ECG的反复测量对于评估暴露变化的影响将具有重要意义。

关键词：砷孟加拉心血管疾病心电图心率校正的QT间期环境暴露

Forces and energetics of intermittent swimming

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Acta Mechanica Sinica 2017年第4期33卷 725-732页

作者： Daniel Floryan Tyler van Buren alexander J.Smits Department of Mechanical and Aerospace Engineering Princeton University Princeton NJ 08544 USA

Experiments are reported on intermittent swimming motions. Water tunnel experiments on a nominally two-dimensional pitching foil show that the mean thrust and power scale linearly with the duty cycle, from a value of 0.2 all the way up to continuous motions, indicating that individual bursts of activity in intermittent motions are independent of each other. This conclusion is corroborated by particle image velocimetry（PIV） flow visualizations, which show that the main vortical structures in the wake do not change with duty cycle. The experimental data also demonstrate that intermittent motions are generally energetically advantageous over continuous motions. When metabolic energy losses are taken into account, this conclusion is maintained for metabolic power fractions less than 1.

关键词： intermittent swimming maintained conclusion cycle thrust favorable producing aquatic circles

Deep cover bleeder entry performance and support loading: A case study

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International Journal of Mining Science and Technology 2018年第1期28卷 85-93页

作者： Ted M.Klemetti Mark alexander van Dyke Ihsan Berk Tulu Ground Control Branch NIOSHPittsburgh Mining Research Division Mining Engineering Department West Virginia University

Several questions have emerged in relation to deep cover bleeder entry performance and support loading:how well do current modeling procedures calculate the rear abutment extent and loading? Does an improved understanding of the rear abutment extent warrant a change in standing support in bleeder entries? To help answer these questions and to determine the current utilization of standing support in bleeder entries, four bleeder entries at varying distances from the startup room were instrumented,observed, and numerically *** paper details observations made by NIOSH researchers in the bleeder entries of a deep cover longwall panel—specifically data collected from instrumented pumpable cribs, observations of the conditions of the entries, and numerical modeling of the bleeder entries during longwall *** primary focus was on the extent and magnitude of the abutment loading experienced by the standing *** expected, the instrumentation of the standing supports showed very little loading relative to the capacity of the standing supports—less than 23 Mg load and 2.54 cm *** Flac3D program was used to evaluate these four bleeder entries using previously defined modeling and input parameter estimation *** results indicated only a minor increase in load during the extraction of the longwall *** model showed a much greater increase in stress due to the development of the gateroad and bleeder entries, with about 80% of the increase associated with development and 20% with longwall *** Flac3D model showed very good correlation between expected gateroad loading during panel extraction and that expected based on previous *** results of this study showed that the rear abutment stress experienced by this bleeder entry design was *** farther away from the startup room, the lower the applied load and smaller the convergence in the entry if all else is held ***, the numerical modeling method

关键词： Bleeder entry Standing supports Abutment loading Longwall mining Full extraction

Nitridation of Ni-based alloys:thermodynamics,kinetics,and deformation phenomena accompanying internal precipitation

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Rare Metals 2006年第5期25卷 501-511页

作者： alexander A.Kodentsov Jorma K.Kivilahti Frans J.J.van Loo Laboratory of Materials and Interface Chemistry Eindhoven University of TechnologyP.O.Box 5135600 MBEindhovenThe Netherlands Laboratory of Electronics Production Technology Helsinki University of TechnologyFIN-02150 EspooFinland

When a moderately stable phase is precipitated out during an intemal reaction, the behaviour of the penetrating atoms within the diffusion zone can be interpreted based on thermodynamic considerations. Evidence for “up-hill” diffusion of the penetrating species through the matrix towards the precipitation front during the intemal nitridation of Ni-Cr alloys at 1125℃ and 6000 bar of N2-pressure was predicted. Such behaviour of nitrogen is opposite to the boundary conditions in Wagner＇s description of internal reactions. A volume change associated with the precipitation reaction resulted in a stress gradient between the alloys surface and the intemal nitridation front. Stress relief occurred mainly by transport of nickel to the gas/metal interface. Pipe diffusion-controlled creep is the dominant stress accommodation mechanism during nitriding of dilute Ni-Cr alloys at 700℃ under a flowing NH3 ＋ H2 gas mixture.

关键词： nitridation nickel alloys thermodynamics diffusion internal precipitation