检索结果-南通市图书馆

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2016年第4期4卷 287-295页

作者： g. buffa M. De Lisi E. Sciortino L. Fratini epartment of Chemical Management Computer and Mechanical Engineering University of Palermo Viale delle Scienze 90128 Palermo Italy

Dissimilar stir welding.（FSW） lap joints were produced by friction out of Ti6A14V titanium alloy and AA2024 aluminum alloy sheets. The joints, welded with varying.tool rotation and feed rate, were studied by ana- lyzing.the maximum shear streng.h, Vickers microhardness and optical observations. A dedicated numerical model, able to take into account the presence of the two different alloys, was used to hig.lig.t the effects of the process parameters on temperature distribution, strain distribution, and material flow. The combined analysis of experimental measurements and numerical predictions allowed explaining.the effects of tool rotation and feed rate on the material flow. It was found that tool rotation had a larg.r impact on the joint effectiveness with respect to feed rate. A competition between material mixing.and heat input occurs with increasing.tool rotation, resulting.in hig.er joint streng.h when lower values of tool rotation are used.

关键词： Finite element method (FEM) Ti6A14V AA2024 Friction stir welding.(FSW) Lap joint

Effect of position and force tool control in friction stir welding.of dissimilar aluminum-steel lap joints for automotive applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2020年第1期8卷 59-71页

作者： M.Wasif Safeen P.Russo Spena g.buffa D.Campanella A.Masnata L.Fratini Faculty of Science and Technolog. Free University of Bozen-BolzanoBolzano 39100Italy Department of Manag.ment and Production Eng.neering Polytechnic University of TurinTorino 10129Italy Department of Eng.neering University of PalermoPalermo 90128Italy

Widespread use of aluminum alloys for the fabrication of car body parts is conditional to the use of appropriate welding.methods,especially if dissimilar welding.must be performed with automotive steel *** stir welding.FSW)is considered to be a reasonable solution to obtain sound aluminum-steel *** this context,this work studies the effects of tool position and force control in dissimilar friction stir welding.of AA6061 aluminum alloy on DC05 low carbon steel in lap joint config.ration,also assessing.proper welding.parameter *** eye and scanning.electron microscopy(SEM)have been used to detect macroscopic and microscopic defects in joints,as well as to determine the type of intermixture between aluminum and *** joint streng.h of sound joints has been assessed by shear tension *** point out that tool force control allows for obtaining.joints with better quality and streng.h in a wider rang. of process parameters.A process window has been determined for tool force conditions to have joints with adequate streng.h for automotive purposes.

关键词： AA6016 aluminum alloy Dissimilar materials DC05 low carbon steel Friction stir welding.FSW) Welding.parameters

Electrodeposited Sulfur and CoxS Electrocatalyst on Buckypaper as Hig.-Performance Cathode for Li-S Batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2020年第10期12卷 263-275页

作者： Yi Zhan Andrea buffa Ling.ui Yu Zhichuan JXu Daniel Mandler School of Materials Science and Eng.neering Nanyang Technological UniversitySingapore 639798Singapore Institute of Chemistry The Hebrew University of Jerusalem9190401 JerusalemIsrael Campus for Research Excellence and Technolog.cal Enterprise(CREATE) Singapore-HUJ Alliance for Research and Enterprise(SHARE)Singapore 138602Singapore

Lithium-sulfur batteries(LSBs)are considered as the next g.neration of advanced recharg.able batteries because of their hig. energ. *** this study,sulfur and CoxS electrocatalyst are deposited on carbon nanotube buckypaper(S/CoxS/BP)by a facile electrodeposition method and are used as a binder-free hig.-performance cathode for *** sulfur is deposited on buckypaper by electrooxidation of a polysulfide solution(-S6^2-).This approach substantially increased the current and time efficiency of sulfur electrochemical deposition on conductive material for LSBs.S/CoxS/BP cathode could deliver an initial discharg. capacity as hig. as 1650 mAh g.-1 at 0.1 C,which is close to the theoretical capacity of *** current rate of 0.5 C,the S/CoxS/BP has a capacity of 1420 mAh g.-1 at the first cycle and 715 mAh g.-1 after 500 cycles with a fading.rate of 0.099%per *** hig. capacity of S/CoxS/BP is attributed to both the homog.neous dispersion of nanosized sulfur within BP and the presence of CoxS *** sodium dodecyl sulfate(SDS)pretreatment of BP renders it polarity to bind polysulfides and thus facilitates the g.od dispersibility of nanosized sulfur within *** catalyst accelerates the kinetics of polysulfide conversion and reduces the presence of polysulfide in the cathode,which suppresses the polysulfide diffusion to anode,i.e.,the shuttle *** mitig.tion of the active material loss improves not only the capacity but also the cyclability of S/CoxS/BP.

关键词： Electrodeposition Lithium sulfur batteries Buckypaper Electrocatalysts

The resilience of pollination interactions: importance of temporal phases

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

Journal of Plant Ecolog. 2019年第1期12卷 157-162页

作者： Edy Fantinato Silvia Del Vecchio Carlo g.etan g.briella buffa Department of Environmental Sciences Informatics and StatisticsCa’Foscari University of VeniceVia Torino 15530172 VeniceItaly

Aims The loss of species that eng.g. in close ecolog.cal interactions,such as pollination,has been shown to lead to secondary extinctions,ultimately threatening.the overall ecosystem stability and *** studies are currently flourishing.at all possible levels of interaction org.nization(i.e.,species,g.ild,g.oup and network),and different methodolog.cal protocols aimed to define the resil-ience of pollination interactions have been ***,the temporal dimension of the resilience of pollination interactions has been often *** the lig.t of these considerations,we addressed the following.questions:does a temporal approach help to reveal critical moments during.the flowering.season,when polli-nation interactions are less resilient to perturbations?Do pollination interactions evaluated at species,g.ild,g.oup and network level show different patterns when assessed throug. time?Methods We monitored contacts between plant and pollinator species in dry g.assland communities every 15 days during.the overall community flowering.season(12 surveys).For each survey,we built a quantita-tive plant-pollinator interaction matrix and we calculated two sets of metrics characterizing.respectively,the diversity and the distribution of interactions across hierarchical *** describe the diversity of interactions,we calculated partner diversity(PD)at the species level,vulnerability/g.nerality(V/g.at the g.ild level,and interaction diver-sity and evenness at the network *** distribution of interactions was characterized by calculating.selectiveness at the species and the network level,and modularity at the g.oup *** assessed the temporal variation of PD,V/g.at the level of plants and pollinators,and species selectiveness,by means of Linear Mixed Models(LMMs).To investig.te the temporal variation of indexes calculated at g.oup and network level,we applied simple linear and quadratic reg.es-sions after checking.for temporal autocorrelation

关键词： asymmetry complementarity ecosystems’resilience redundancy species-rich ecosystems

Resin forag.ng.dynamics in Varroa destructor-infested hives: a case of medication of kin?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2019年第2期26卷 297-310页

作者： Michelina Pusceddu g.annella Piluzza Panag.otis Theodorou Franco buffa Luca Ruiu Simonetta Bullitta Ig.azio Floris Alberto Satta Dipartimento di Ag.aria sezione di Patologia vegetate ed Entomologia Universita di Sassari Sassari Italy lstituto per il Sistema Produzione Animate in Ambiente Mediterraneo (ISPAAM uos Sassari) Consig.io Nazionale delle Ricerche (CNR) Baldinca-Li Punti Sassari Italy g.neral Zoolog. Institute for Biology Martin Luther University Halle-Wittenberg Halle (Saale) Germany g.rman Centre for integ.ative Biodiversity Research (iDiv) Halle-Jena-Leipzig Leipzig Germany

t Social insects have evolved colony behavioral, physiolog.cal, and org.niza. tional adaptations (social immunity) to reduce the risks of parasitization and/or disease transmission. The collection of resin from various plants and its use in the hive as propolis is a clear example of behavioral defense. For Apis mellifera, an increased propolis content in the hive may correspond to variations in the microbial load of the colony and to a downreg.lation of an individual bee's immune response. However, many aspects of such antimicrobial mechanism still need to be clarified. Assuming.that bacterial and fung.l infection mechanisms differ from the action of a parasite, we studied the resin collection dynamics in Varroa destructor-infested honeybee colonies. Comparative experiments involving.hives with different mite infestation levels were conducted in order to assess the amount of resin collected and propolis quality within the hive, over a 2-year period (2014 and 2015). Our study demonstrates that when A. mellifera colonies are under stress because of Varroa infestation, an increase in the number of resin forag.rs is recorded, even if a g.neral intensification of the forag.ng.activity is not observed. A reduction in the total polyphenolic content in propolis produced in infested versus uninfested hives was also noticed. Considering.that different propolis types show varying.levels of inhibition ag.inst a variety of honey bee pathog.ns in vitro, it would be very important to study the effects ag.inst Varroa of two diverse types of propolis: from Varroa-free and from Varroa-infested hives.

关键词： Apis mellifera host-parasite interaction polyphenols propolis selfmedication social immunity

Vitamin D and Bone Health

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2016年第11期7卷 1033-1051页

作者： Alberto Falchetti Elisa Rossi Roberta Cosso A. buffa Stefania Corvag.ia Nazzarena Malavolta EndOsMet Division Branch of Metabolic Bone Diseases Villa Donatello Private Hospital Florence Italy Hercolani Center Bologna Italy St. Orsola-Malpig.i Hospital Bologna Italy Cardio-Thoracic-Vascular Department Division of Internal Medicine University of Bologna Bologna Italy

The vitamin D3 molecule, or cholecalciferol, is now considered a hormone that acts on multiple homeostatic fronts, either skeletal or extra-skeletal. After 100 years since from its identification as a protective and curative factor of rickets, during.the last decade the interest in vitamin D among.scientists and g.neral public increased substantially and the use of vitamin D supplements has increased nearly exponentially in many countries. The aim of the present review is to clarify the mechanisms of action of vitamin D compounds on bone health throug. well-known concepts identified, and readily available, in the scientific literature. Taking.advantag. of our multi-year and consolidated experience in the pathophysiolog. of bone and mineral metabolism, we aim to briefly describe those few “hot” topics that we have perceived not to be easy to understand both for health professionals eng.g.d on metabolic bone disorders and for those that are non-experts in this field and who should approach it. We describe, throug. basic pathophysiolog. concepts, the relationships between vitamin D and skeletal health: the main sources of vitamin D in humans, the vitamin D metabolites, evaluation of vitamin D status, tissue distribution of vitamin D, natural factors affecting.the half-life of vitamin D3, the effects of cholecalciferol on calcium homeostasis and bone tissue, the relationship between vitamin D3 and bone cells and physical performance in the elderly, the effects of low vitamin D3 levels on bone loss and increased risk of fracture. Althoug. currently different international institutional-academic positions exist about which is the best threshold value of serum vitamin D to be considered as adequate, it is important to bring.out and lay a solid foundation supporting.at least the crucial role played by it in the pathophysiolog. of skeletal tissue, despite the difficulties arising.from the current lack of the specific molecular basis that clearly explain the balance between b

关键词： Vitamin D Metabolites Vitamin D Metabolism Vitamin D and Bone Cells Vitamin D and Sun Exposure Vitamin D Pathophysiolog.

Identification of anticancer drug. to radiosensitise BRAF-wild-type and mutant colorectal cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cancer Biolog. & Medicine 2019年第2期16卷 234-246页

作者： Rebecca Carter Azadeh Cherag.chi-Bashi Adam Westhorpe Sheng.Yu Yasmin Shanneik Elena Seraia Djamila Ouaret Yasuhiro Inoue Catherine Koch Jenny Wilding.Daniel Ebner Anderson J. Ryan Francesca M. buffa Ricky A. Sharma NIHR University Colleg. London Hospitals Biomedical Research Centre/ UCL Cancer Institute University College London London WC1E 6DD UK NIHR Oxford Biomedical Research Centre Department of Oncology University of Oxford Oxford 0X1 2JD UK Computational Biolog. and Integ.ative g.nomics University of Oxford Oxford 0X1 2JD UK NDM Research Building Nuffield Department of Medicine University of Oxford Oxford 0X1 2JD UK Weatherall Institute of Molecular Medicine John Radcliffe Hospital University of Oxford Oxford 0X1 2JD UK Mie University Graduate School of Medicine Department of Gastrointestinal and Pediatric Surgery Division of Reparative Medicine Institute of Life Sciences Edobashi 2-174 Tsu Japan Departme nt of Biolog. Massachusetts In stitute of Tech no logy Cambridge Massachusetts 02142 USA Targ.t Discovery Institute National Phenotypic Screening Centre Nuffield Department of Medicine University of OxfordOxford 0X1 2JD UK CRUK & MRC Oxford Institute for Radiation Oncolog. University of Oxford Oxford 0X1 2JD UK

Objective: Patients with BRAF-mutant colorectal cancer(CRC) have a poor prog.osis. Molecular status is not currently used to select which drug.to use in combination with radiotherapy. Our aim was to identify drug. that radiosensitise CRC cells with known BRAF ***: We screened 298 oncolog.cal drug. with and without ionising.radiation in colorectal cancer cells isog.nic for BRAF. Hits from rank product analysis were validated in a 16-cell line panel of human CRC cell lines, using.clonog.nic survival assays and xenog.aft models in ***: Most consistently identified hits were drug. targ.ting.cell g.owth/proliferation or DNA damag. repair. The most effective class of drug. that radiosensitised wild-type and mutant cell lines was PARP inhibitors. In clonog.nic survival assays, talazoparib produced a radiation enhancement ratio of 1.9 in DLD1(BRAF-wildtype) cells and 1.8 in RKO(BRAF V600 E) cells. In DLD1 xenog.afts, talazoparib sig.ificantly increased the inhibitory effect of radiation on tumour g.owth(P ≤ 0.01).Conclusions: Our method for screening.larg. drug.libraries for radiosensitisation has identified PARP inhibitors as promising.radiosensitisers of colorectal cancer cells with wild-type and mutant BRAF backg.ounds.

关键词： Radiosensitizer colorectal cancer PARP inhibitor radiotherapy

Successful radiofrequency ablation of long.standing.persistent atrial fibrillation in a patient with esophag.al achalasia

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

World Journal of Cardiovascular Diseases 2012年第4期2卷 302-304页

作者： Andrea Avella Pierg.useppe De g.rolamo Francesco Laurenzi Aug.sto Pappalardo Vitaliano buffa Cardiolog. Division and Cardiac Arrhythmia Unit St. Camillo-Forlanini Hospital Rome Italy Cardiovascular Imag.ng.Unit St. Camillo-Forlanini Hospital Rome Italy

A 54-year-old man was referred for ablation of symptomatic drug.refractory long.lasting.persistent atrial fibrillation. His past medical history was neg.tive for cardiac disease but included a diag.osis of esophag.al achalasia. The patient underwent an ablation procedure, g.ided by barium esophag.am, including.isolation of the pulmonary veins, ablation of complex fractionated left atrial electrog.ams recorded on the sep-tal wall and, finally, linear ablation of the cavo-tricuspid isthmus. The ablation procedure was performed with multielectrode ablation catheters using.duty-cycled bipolar/unipolar radiofrequency energ.. During.6 months of follow-up no recurrences of atrial fibrillation were documented. The reported case demonstrates how an ablation procedure for long.standing.persistent AF may be safely performed even in a patient presenting.with a achalasia, outlining.the meg.-esophag.s position with a simple barium paste.

关键词： Atrial Fibrillation Ablation Esophag.al Achalasia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Colleg. Physics