检索结果-南通市图书馆

Mechanical properties and microstructure of composites produced by recycling metal chips

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2018年第9期25卷 1070-1079页

作者： Abdullah Aslan Aydin Günes Emin Salur Omer Sinan Shin Hakan Burak Karadag Ahmet Akdemir Department of Mechanical Engineering Selcuk UniversityKonya 42079Turkey Department of Metallurgy and Materials Engineering Necmettin Erbakan UniversityKonya 42079Turkey Department of Aircraft Engineering Necmettin Erbakan UniversityKonya 42079Turkey

In this study, the processing and mechanical properties of porous metal matrix composites(MMCs) composed of spheroidal cast iron chips(GGG40) and bronze chips(CuSn10) and formed by hot isostatic pressing were investigated. Bronze chips(CuSn10) were used as a matrix component, and spheroidal cast iron(GGG40) chips were used as a reinforcement component. The MMCs were produced with different CuSn10 contents(90 wt%, 80 wt%, 70 wt%, and 60 wt%). The hot isostatic pressing process was performed under three different pressures and temperatures. The produced MMCs were characterized using density tests, Brinell hardness tests, and compression tests. In addition, the consolidation mechanism was investigated by X-ray diffraction(XRD) analysis and scanning electron microscopy. The test results were compared with those for bulk CuSn10 and bulk GGG40. Mechanical tests results revealed that the metallic chips can be recycled by using hot pressing and that the mechanical properties of the produced MMCs were similar to those of bulk CuSn10. XRD and microscopy studies showed that no intermetallic compounds formed between the metallic chips. The results showed that the CuSn10 and GGG40 chips were consolidated by mechanical interlocking.

关键词： metal matrix composite microstructure metal chips recycle mechanical behavior

Modeling the impact of quarantine during an outbreak of Ebola virus disease

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2019年第1期4卷 12-27页

作者： Attila Dénes Abba B.Gumel Bolyai Institute University of SzegedAradi vertanúk tere 1.Szeged H-6720Hungary School of Mathematical and Statistical Sciences Arizona State UniversityTempeAZ 85287-1804USA Other affliation:Department of Mathematics and Applied Mathematics University of PretoriaPretoria 0002South Africa

The quarantine of people suspected of being exposed to an infectious agent is one of the most basic public health measure that has historically been used to combat the spread of communicable diseases in human *** study presents a new deterministic model for assessing the population-level impact of the quarantine of individuals suspected of being exposed to disease on the spread of the 2014e2015 outbreaks of Ebola viral *** is assumed that quarantine is imperfect(i.e.,individuals can acquire infection during quarantine).In the absence of quarantine,the model is shown to exhibit global dynamics with respect to the disease-free and its unique endemic equilibrium when a certain epidemiological threshold(denoted byR 0)is either less than or greater than ***,unlike the full model with imperfect quarantine(which is known to exhibit the phenomenon of backward bifurcation),the version of the model with no quarantine does not undergo a backward *** data relevant to the 2014e2015 Ebola transmission dynamics in the three West African countries(Guinea,Liberia and Sierra Leone),uncertainty analysis of the model show that,although the current level and effectiveness of quarantine can lead to significant reduction in disease burden,they fail to bring the associated quarantine reproduction number(R Q0)to a value less than unity(which is needed to make effective disease control or elimination feasible).This reduction of R Q0 is,however,very possible with a modest increase in quarantine rate and *** is further shown,via sensitivity analysis,that the parameters related to the effectiveness of quarantine(namely the parameter associated with the reduction in infectiousness of infected quarantined individuals and the contact rate during quarantine)are the main drivers of the disease transmission ***,this study shows that the singular implementation of a quarantine intervention strategy can lead to the effective control or

关键词： Ebola virus disease Quarantine Global dynamics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

交通安全分析框架

公路交通科技 1996年第A期13卷 39-45页

作者： joha.,O 陈国靖

Study the Specifications of the Thread through the Construction of the Pipe on the Ring Spinning Machine

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 Biomedical Science and Engineering 2015年第4期8卷 295-319页

作者： Mohamad Yaser joha Easa Morad Postgraduate Student (Msc.) Department of Mechanical Engineering of Textile Industries and Their Technologies Faculty of Mechanical and Electrical Engineering Damascus University Damascus Syria Ass. Prof. Mechanical Department Faculty of Mechanical and Electrical Engineering Damascus University Damascus Syria

In ring spinning, tension develops in the yarn mainly because, to move the Traveler and the balloon length, Lb, around the spindle axis, and to wind the yarn onto the spinning bobbin, work must be done against the frictional force of the ring on the Traveler and of the Traveler on the yarn, as well as against the air drag on the Traveler and on the balloon length. This work is additional to that needed to overcome the friction of the spindle bearings and the air drag on the forming yarn package. The tensions in the yarn during ring spinning may be considered with respect to three zones: 1) the yarn formation zone (i.e., the zone between the pigtail lappet guide and the front rollers of the drafting system);2) the winding zone (i.e., the zone between the Traveler and the bobbin forming zone);3) the balloon zone (i.e., the zone between the Traveler and lappet guide), where the yarn tension changes noticeable shape by relation with Winding Qatar (the yarn tension increases whenever Winding Qatar reduces).

关键词： The Yarn Formation Zone The Winding Zone The Balloon Zone

Co-substitution of zirconium and neodymium on hyperfine interactions and AC susceptibility of SrFe12O19 nanohexaferrites

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 Rare Earths 2020年第3期38卷 265-273页

作者： M.A.Almessere Y.Slimani H.Güngünes A.Baykal Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia Department of Biophysics Institute for Research&Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia Department of Physics Hitit University19030Cevre Yolu Bulvan-CorumTurkey Department of Nano-Medicine Research Institute for Research&Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia

This study presents the influence of Zn and Nd co-substitution on structure,morphology,AC susceptibility and ZFC-FC magnetizations of Sr nanohexaferrites(NHFs),SrFe12-x(Zn,Nd)xO19(0.0≤x≤1.0),which was produced by sol-gel *** powder patterns,scanning electron microscopy(SEM) and high-resolution transmission electron spectroscopy(HR-TEM) approve the synthesis of Sr M-type *** spectra show that Zn^2+ions occupy 2 b and 4f1 sites while Nd3+ions locate at 2 a,4f2 and 12 k *** magnetic properties of the produced Sr-NHFs were investigated also by ZFC-FC magnetizations and AC *** to the MFC-MZFC results(between 2 and 400 K),no blocking temperature was detected which indicates the ferromagnetic(FM) behavior of *** lower temperatures,a super-spin glass like behavior is *** AC susceptibility indicates that the magnetic interactions are improved due to the inclusion of low content(x=0.1) of Nd^3+and Zn^2+ions into the ***,with further increasing the Nd^3+and Zn^2+contents(x=0.9),the magnetic interactions are weakened.

关键词： Sr hexaferrites Rare earths Mossbauer spectroscopy AC susceptibility ZFC-FC

Retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness in children with obesity

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2016年第3期9卷 434-438页

作者： Selim Demir Samet ozer Sait Alim Alper Günes Hüseyin Ortak Resul Yilmaz Department of Ophthalmology Faculty of Medicine Gaziosmanpasa University Tokat 60030 Turkey Department of Pediatrics Faculty of Medicine Gaziosmanpasa University Tokat 60030 Turkey

AIM：To evaluate retinal nerve fiber layer（RNFL）thickness analysis of peripapillary optic nerve head（PONH） and macula as well as ganglion cell-inner plexiform layer（GCIPL） thickness in obese children.· METHODS：Eighty-five children with obesity and 30 controls were included in the *** thicknesses of the PONH and macula of each subject＇s right eye were measured by high-resolution spectral-domain optic coherence tomography（OCT）.· RESULTS：The RNFL thicknesses of central macular and PONH were similar between the groups（all P 〉0.05）.The GCIPL thickness was also similar between the ***,the RNFL thickness of temporal outer macula were 261.7±13.7 and 268.9±14.3 μm for the obesity and the control group,respectively（P =0.034）.· CONCLUSION：Obesity may cause a reduction in temporal outer macular RNFL thickness.

关键词： ganglion cell-inner plexiform layer retinalnerve fiber layer thickness optical coherence tomography obesity

Effects of astaxanthin on antioxidant parameters in ARPE-19 cells on oxidative stress model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2019年第6期12卷 930-935页

作者： Yigit Musa Günes Alime Uguz Cihangir Yalcin Tok Ozlem Tok Levent Oz Ahmi Naziroglu Mustafa Department of Ophthalmology Süleyman Demirel University Research and Education HospitalCünür-Isparta 32200Turkey Department of Biophysics Faculty of MedicineSüleyman Demirel University Research and Education HospitalCünür-Isparta 32200Turkey

AIM: To observe the protective effect of astaxanthin(AST) against hydroquinone(HQ) mediated cell death in the apoptotic cascade and evaluate intracellular Ca2+ release, caspase-3, and-9 activation, reactive oxygen species(ROS) production in ARPE-19 ***: We cultured ARPE-19 cells in special mediums and performed MTT tests to determine protective effect of AST, before exposing the cells to HQ in an incubator. We analyzed intracellular Ca2+ release experiments, mitochondrial membrane depolarization, glutathione(GSH), glutathione peroxidase(GSH-Px) and ROS experiments, and apoptosis ***: ROS production ranges depend on the amount of cell death. We computed the correlation between ROS ranges and cell death by 20,70-dichlorofluorescein fluorescence, and Ca2+ levels by Fura-2-AM. HQ-induced cell death found out to rise ranges of caspase-3 and-9, and mitochondrial depolarization. These three steps were delayed by AST ***: ARPE-19 cells are avoided from HQinduced ROS production and caspase-3 and-9 activation by AST. AST may limit the range of caspase synthesis, Ca2+ release and excess production of ROS with antiapoptotic effect. This study proposes a new therapeutic approach for the treatment of age-related macular degeneration.

关键词： apoptosis ARPE-19 cell astaxanthin oxidative stress

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

脑皮层梗塞后的神经组织移植

中国神经精神疾病杂志 1998年第1期24卷 1-5页

作者： joha.,BB 曾进胜

胎脑细胞匀浆或组织块移植是治疗人类中枢神经系统病变的新手段之一。至今，已在帕金森氏病（Ｐａｒｋｉｎｓｏｎｓｄｉｓｅａｓｅ）方面作了大量试尝，新近，也开始用于治疗遗传性舞蹈病。在帕金森病的治疗方面，已取得功能改善的疗... 详细信息

胎脑细胞匀浆或组织块移植是治疗人类中枢神经系统病变的新手段之一。至今，已在帕金森氏病（Ｐａｒｋｉｎｓｏｎｓｄｉｓｅａｓｅ）方面作了大量试尝，新近，也开始用于治疗遗传性舞蹈病。在帕金森病的治疗方面，已取得功能改善的疗效［１，２］。神经移植是否能使大脑...

关键词：脑梗塞脑皮层梗塞神经组织移植

Utilization of Ischemic Preconditioning for Athletes Competing and Training at Altitude:Applications and Perspectives

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 Science in Sport and Exercise 2022年第4期4卷 346-357页

作者： François Billaut Pénélope Paradis-Deschênes Philippe T.Richard Département de kinésiologie Facultéde MédecineUniversitéLaval2300 rue de la TerrasseQuébecQC G1V 0A6Canada Département des sciences de la santé Universitédu QuébecàChicoutimiChicoutimiQCCanada

Acute exposure to altitude negatively impacts exercise tolerance and reduces athletes’race performance due to lower atmos-pheric and body tissues oxygen partial *** exposure to altitude has also been used for several decades by athletes to increase training ***,the decline in arterial oxygen saturation also impacts'trainability'and athletes are forced to travel to lower altitude for intensified *** the athlete preparing for altitude,the advantages of properly timed terrestrial acclimatization and/or sea-level hypoxia-based pre-acclimatization recommendations are ***,the associated cost,demands,and time investment make these best-practice strategies difficult or impossible to implement for many *** perspective and opinion article summarizes current knowledge on the potency of ischemic preconditioning(i.e.,a sequence of transient ischemic episodes followed by reperfusion)to enhance the pulmonary,vascular,and metabolic determinants of performance at altitude with the aim to derive implications to accelerate or facilitate altitude acclimatization for varied *** discuss potential applications for athletes and propose innovative questions for future research in this field.

关键词： Occlusion Ischemia Acclimatization Hypoxia Oxygenation Performance