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Friction 2024年第4期12卷 796-811页

作者： Samuel BOND Robert L.JACKSON german MILLS Department of Chemistry and Biochemistry Auburn UniversityAuburn 36849-5412USA Department of Mechanical Engineering Auburn UniversityAuburn 36849-5412USA

Leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact performance.These findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)particles.Reciprocating rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without additives.Friction forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear grove.Micron-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon lubricants.Numerous findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关键词： electric motor bearings wheel bearings electric vehicles arcing electrically induced bearing damage pitting leakage current stray current

Leaf habit differentiation explains trait tradeoffs across savanna woody plants

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Forest Ecosystems 2024年第3期11卷 287-295页

作者： Yangsiding Wang Da Yang german Vargas G. Guangyou Hao Jennifer S.Powers Yan Ke Qin Wang Yunbing Zhang Jiaolin Zhang CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China University of Chinese Academy of Sciences Beijing 100049China School of Biological Sciences University of UtahSalt Lake CityUT 84112USA CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Department of Ecology Evolution and BehaviorUniversity of MinnesotaSt PaulMN 55108USA

Identifying how leaf habit subdivisions link to the fast–slow and avoidance–tolerance trait tradeoffs can provide new insight into divergence in ecophysiological strategies among plant functional groups. Here, we tested a hypothesis that the differentiation across deciduous, semi-deciduous and evergreen woody species contributes to physiological trait tradeoffs in a dry-hot valley savanna. We investigated 11 photosynthetic, morphological and hydraulic traits of 24 species including 8 deciduous, 10 semi-deciduous and 6 evergreen species. Deciduous species were grouped in the fast and avoidance side associated with high values of maximum photosynthetic rates,stomatal conductance and leaf size, while evergreen species were grouped in the slow and tolerance side associated with high photosynthetic water use efficiency, leaf mass per area, sapwood density, Huber value, leaf water potential at turgor loss point and water potential causing 50% loss of stem hydraulic conductance. Semideciduous species generally had intermediate trait values and represented different physiological characteristics when compared to deciduous and evergreen species. The physiological trait tradeoffs showed a close linkage to the differentiation of these three leaf habits. Our findings clearly reveal trait tradeoffs related to fast–slow and avoidance–tolerance strategies among diverse savanna plants, suggesting a syndrome in multiple ecophysiology strategies across different leaf habits.

关键词： Dry-hot habitat Gas exchange Hydraulics Phenology Tolerance Valley savanna

An egg-shell bifunctional CeO_(2)-modified NiPd/Al_(2) O_(3) catalyst for petrochemical processes involving selective hydrogenation and hydroisomerization

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Journal of Rare Earths 2021年第11期39卷 1382-1388,I0003页

作者： Franklin J.Mendez Javier A.Alves Yahse Rojas-Challa Oscar Corona Yanet Villasana Julia Guerra german garcia-colli Osvaldo M.Martinez Joaquin L.Brito Centro de Quimica Instituto Venezolano de Invesdgaciones CientfficasCarretera PanamericanaKm 11 Altos de PipeCaracas1020AVenezuela Departamento de Estado Solido Instituto de FisicaUniversidad Nacional Autonoma de MexicoCiudad UniversitariaCiudad de Mexico04510Mexico Departamento de Ingenieria Quimica Facultad de Ingenieria(UNLP)and Centro de Investigacion y Desarrollo en Ciencias Aplicadas"Dr.J.J.Ronco"(CINDECA)CCT-La Plata-CONICET-UNLPLa Plata1900Argentina Departamento de Quimica Analitica Facultad de QufmicaUniversidad Nacional Autonoma de MexicoCiudad UniversitariaCiudad de Mexico04510Mexico Instituto Tecnoldgico Venezolano Del Petroleo SA. Petrole os de Venezuela SA.Urb.Santa Rosa-Sector El TamborLos Teques1201Venezuela Instituto Superior de Formacion Docente Salome Urena Esquina Leonardo D'VinciSanto Domingo10114Republica Dominicana Biomass to Resources Group Universidad Regional Amazonica IkiamKm 7 via MuyunaTena150150Ecuador Departamento de Termodinamica y Fenomenos de Transferencia Universidad Simon BolivarValle de SartenejasCaracas1086Venezuela

The catalytic performance during the 1-butyne hydrogenation using two reduced Al_(2) O_(3)-supported Pdbased catalysts was carried out in a total recirculation system with an external fixed-bed reactor.The lab-prepared egg-shell NiPd/CeO_(2)-Al_(2) O_(3) catalyst(NiPdCe) with Pd loading=0.5 wt%,Ni/Pd atomic ratio=1 and CeO_(2) loading=3 wt% was synthesized and characterized,and it was compared with an egg-shell Al_(2) O_(3)-supported Pd based commercial catalyst(PdCC).The reduced catalysts were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,and high-resolution transmission electron microscopy.The textural characteristics and ammonia temperature-programmed desorption profiles of the fresh(unreduced) catalysts were also obtained.Both catalysts show high 1-butyne conversion and selectivity to 1-butene,but the catalysts also present important differences between hydroisomerizing and hydrogenating capabilities.NiPdCe catalyst shows higher capability for hydroisomerization reactions,while the PdCC catalyst exhibits higher hydrogenating capability.The observed catalytic performances can be interesting for some industrial processes and can provide a guideline for the development of a Pd-based catalyst with specific catalytic properties.

关键词： 1-Butyne Bifunctional catalyst Egg-shell Hydrogenation Hydroisomerization NiPd catalyst

HVOF-sprayed HAp/S53P4 BG composite coatings on an AZ31 alloy for potential applications in temporary implants

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Journal of Magnesium and Alloys 2024年第1期12卷 345-360页

作者： Carlos A.Poblano-Salas John Henao Astrid L.Giraldo-Betancur Paola Forero-Sossa Diego german Espinosa-Arbelaez Jorge A.González-Sánchez Luis R.Dzib-Pérez Susana T.Estrada-Moo Idelfonso E.Pech-Pech CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-Cinvestav Libramiento Norponiente#2000.Fraccionamiento Real de JuriquillaQuerétaro 76230Mexico Universidad Tecnológica de Querétaro Av.Pie de la Cuesta N°2501Querétaro 76148Mexico CIDESI Av.Playa Pie de la Cuesta No 702Col.San PabloQuerétaro 76125Mexico Center for Corrosion Research Autonomous University of CampecheAv.Héroe de Nacozari No.480P.C.24070San Francisco de CampecheCam.Mexico

Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration,considering that both phases have different reaction and dissolution rates under in-vitro conditions.In the present work,75%wt.HAp-25%wt.S53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/S53P4 BG composite coatings on a bioresorbable AZ31 alloy.The study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those coatings.Different characterization techniques,such as scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,were employed to characterize relevant structural and microstructural properties of the composite coatings.The results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved(max 550℃)and the differences in coefficients of thermal expansion.It was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the coatings.In addition,in-vitro electrochemical studies were performed on the obtained HAp/S53P4 BG composite coatings and compared against the uncoated AZ31 alloy.The results showed a significant decrease in hydrogen evolution(at least 98%)when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid(SBF).

关键词： Coatings Composites Thermal spray Temporary implants Hydrogen evolution

Prediction of Moments in the Particles on Demand Method for LBM

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Communications in Computational Physics 2023年第1期33卷 144-173页

作者： Elizaveta Zipunova Anastasia Perepelkina Vadim Levchenko german Zvezdin Keldysh Institute of Applied Mathematics RAS 4 Miusskaya sq.MoscowRussia125047 Moscow State University 1 Ulitsa KolmogorovaMoscowRussia119991

PonD is a method to extend LBM calculations to arbitrary ranges of Mach number and temperature.The current work was motivated by the issue of mass,momentum and energy conservation in the PonD method for LBM.The collision guarantees their conservation,thus,the study involves all aspects of the streaming step:both coordinate and velocity space discretizations,gauge transfer method,resolution of the scheme implicitness.After obtaining the expressions for the change of moments in the system in a time update of the scheme,it was found that the scheme can be formulated as explicit in some cases.Thus,we found the sufficient conditions to make Pond/RegPonD computations explicit and mass,momentum,and energy conserving.The scheme was implemented in the explicit form,and validated for several test cases.

关键词： LBM compressible off-grid

Interaction between xylanase and a proton pump inhibitor on broiler chicken performance and gut function

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Animal Nutrition 2022年第1期8卷 277-288页

作者： Gemma Gonzalez-Ortiz Sophie A.Lee Kirsi Vienola Kari Raatikainen german Jurgens Juha Apajalahti Michael R.Bedford AB Vista MarlboroughWiltshireSN84ANUnited Kingdom Alimetrics Ltd. Koskelontie 19 BEspooFinland

Three hundred thirty-six Ross 308 male broiler chicks were used in a 21-d study to explore performance and gut function when treated with a proton pump inhibitor(PPI;0 or 89 mg/kg)in a 2×2 factorial arrangement with a xylanase(Xyl;0 or 0.1 g/kg)to determine if the beneficial activity of arabinoxylan(AX)depolymerisation,through arabinoxylo-oligosaccharides(AXOS)production,starts in the upper gastrointestinal tract.Treatment with the PPI started from d 14,and by d 21 animal performance had deteriorated(P<0.001).An interaction was observed between PPI and Xyl for feed conversion ratio(FCR)(P<0.05),whereby the combination reduced the negative effect of PPI on FCR.Application of PPI raised digesta pH in the gizzard and caecum(P<0.05),increased protein concentrations in the lower gut(P<0.05)and reduced intake of digestible nutrients(P<0.05).Caecal concentrations of indole,p-cresol,ammonia and the ratio of total volatile fatty acid(VFA)to butyric acid were increased with PPI(P<0.05),indicating enhanced protein fermentation.Xylanase activity in the digesta were greatest in the caeca,especially when Xyl was supplemented(P<0.001).The concentration of total soluble AX was greater in the gizzard and ileal digesta with Xyl supplementation(P<0.05),supporting the depolymerisation action of xylanase even under acidic conditions.These data suggest xylanase may function in the gizzard even though pH is not optimal for activity and emphasises the importance of chlorohydric acid secretions in ensuring overall optimum gut function.AX depolymerisation benefits animal performance although it is still unknown how the AXOS produced with xylanase supplementation in the upper gastrointestinal tract influence the microbial populations and overall gut functionality.

关键词： Xylanase Proton pump inhibitor Arabinoxylan degradation Protein fermentation Broiler chicken

Confinement effects in methanol to olefins catalysed by zeolites： A computational review

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Frontiers of Chemical Science and Engineering 2016年第1期10卷 76-89页

作者： german Sastre Instituto de Tecnologia Quimica U.P.V.-C.S.I.C Universidad Politecnica de Valencia Avenida Los Naranjos s/n 46022 Valencia Spain

Small pore zeolites, containing 8-rings as the largest, are widely employed as catalysts in the process of methanol-to-olefins （MTO）. Reactants and products dif- fuse with constraints through 8-rings and this is one of the reaction bottlenecks related to zeolite micropore topology. Small pore zeolites and silicon-aluminophosphates （SAPOs） containing cavities, where olefins are mainly formed through the hydrocarbon pool （HP） mechanism, are frequently tested for MTO. Shape selectivity of transition states within the side-chain methylation will be reviewed as this is one of the controlling steps of the MTO process, with particular attention to the role of hexam- ethylbenzene （HMB） and heptamethylbenzenium cation （HeptaMB~）, which are the most tipically detected reaction intermediates, common to the paring and side-chain routes within the HP mechanism. The relative stability of these and other species will be reviewed in terms of confinement effects in different cage-based zeolites. The role of the different alkylating agents, methanol, dimethyl ether （DME）, and surface methoxy species （SMS） will also be reviewed from the computational viewpoint.

关键词： small pore zeolites SAPOs methanol-to-olefins hydrocarbon pool mechanism alkylation of poly-methylbenzenes

Notes on the family Brassicaceae in China

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Journal of Systematics and Evolution 2009年第3期47卷 202-219页

作者： Dmitry A german Altai State University

A critical revision of the collections of Brassicaceae in some Chinese (PE, XJA, XJBI, XJFA, XJNM, XJU) and foreign (LE, P) herbaria is made. One genus, Neurotropis (DC.) F. K. Mey., and 11 species, Alyssum szarabiacum Nyár., Barbarea stricta Andrz., Erysimum czernjajevii N. Busch, Erysimum kotuchovii D. german, Erysimum mongolicum D. german, Lepidium karelinianum Al-Shehbaz, Matthiola superba Conti, Neurotropis platycarpa (Fisch. & Mey.) F. K. Mey., Ptilotrichum dahuricum Peschkova, Sisymbrium subspinescens Bunge, and Smelowskia micrantha (Botsch. & Vved.) Al-Shehbaz & S. I. Warwick, are reported from China for the first time. Six species, Aphragmus involucratus (Bunge) O. E. Schulz, Dontostemon perennis C. A. Mey., Goldbachia torulosa DC., Lepidium amplexicaule Willd., Neotorularia brevipes (Kar. & Kir.) Hedge & J. Léonard, and Parrya stenocarpa Kar. & Kir., are confirmed to occurr in China. Five species, Dontostemon integrifolius (L.) C. A. Mey., Draba zangbeiensis L. L. Lou, Lepidium alashanicum H. L. Yang, Sinapis arvensis L., and Strigosella brevipes (Bunge) Botsch., are reported as novelties for some provinces in China, and Strigosella hispida (Litv.) Botsch. occurs in Xinjiang, China. However, the occurrence of one genus, Pseudoarabidopsis Al-Shehbaz, O’Kane & Price, and four species, Draba huetii Boiss., Eutrema halophilum (C. A. Mey.) Al-Shehbaz & S. I. Warwick, Galitzkya spathulata (Steph. ex Willd.) V. Bocz., and Pseudoarabidopsis toxophylla (Bieb.) Al-Shehbaz, O’Kane & Price, could not be confirmed in China. The occurrence of six species, Aphragmus bouffordii Al-Shehbaz, Barbarea orthoceras Ledeb., Lepidium latifolium L., Ptilotrichum canescens (DC.) C. A. Mey., Strigosella hispida (Litv.) Botsch., and Strigosella scorpioides (Bunge) Botsch., is not confirmed in certain provinces of China. All names follow the latest taxonomic treatment for relevant groups; detailed morphological descriptions of the newly recorded taxa are provided; and distinguishing characters from related species already known in

关键词： Brassicaceae China Cruciferae distribution new record.

In vivo solid phase microextraction for therapeutic monitoring and pharmacometabolomic fingerprinting of lung during in vivo lung perfusion of FOLFOX

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Journal of Pharmaceutical Analysis 2023年第10期13卷 1195-1204页

作者： Nikita Looby Anna Roszkowska Miao Yu german Rios-Gomez Mauricio Pipkin Barbara Bojko Marcelo Cypel Janusz Pawliszyn Department of Chemistry University of Waterloo200 University Avenue WestWaterlooONN2L 3G1Canada Department of Pharmaceutical Chemistry Medical University of Gdansk80-416GdanskPoland Division of Thoracic Surgery University Health NetworkTGH200 Elizabeth StTorontoONM5G 2C4Canada Department of Pharmacodynamics and Molecular Pharmacology Collegium Medicum in BydgoszczNicolaus Copernicus University in Torun85-089BydgoszczPoland

In vivo lung perfusion(IVLP)is a novel isolated lung technique developed to enable the local,in situ administration of high-dose chemotherapy to treat metastatic lung cancer.Combination therapy using folinic acid(FOL),5-fluorouracil(F),and oxaliplatin(OX)(FOLFOX)is routinely employed to treat several types of solid tumours in various tissues.However,F is characterized by large interpatient variability with respect to plasma concentration,which necessitates close monitoring during treatments using of this compound.Since plasma drug concentrations often do not reflect tissue drug concentrations,it is essential to utilize sample-preparation methods specifically suited to monitoring drug levels in target organs.In this work,in vivo solid-phase microextraction(in vivo SPME)is proposed as an effective tool for quantitative therapeutic drug monitoring of FOLFOX in porcine lungs during pre-clinical IVLP and intravenous(IV)trials.The concomitant extraction of other endogenous and exogenous small molecules from the lung and their detection via liquid chromatography coupled to high resolution mass spectrometry(LC-HRMS)enabled an assessment of FOLFOX's impact on the metabolomic profile of the lung and revealed the metabolic pathways associated with the route of administration(IVLP vs.IV)and the therapy itself.This study also shows that the immediate instrumental analysis of metabolomic samples is ideal,as long-term storage at80℃ results in changes in the metabolite content in the sample extracts.

关键词： In vivo lung perfusion Solid-phase microextraction Chemotherapy Metabolomics Therapeutic drug monitoring

GOECP/SEOR radiotheraphy guidelines for non-small-cell lung cancer

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World Journal of Clinical Oncology 2022年第4期13卷 237-266页

作者： Nuria Rodriguez De Dios Arturo Navarro-Martin Cristina Cigarral Rodolfo Chicas-Sett Rafael garcia Virginia garcia Jose Antonio Gonzalez Susana Gonzalo Mauricio Murcia-Mejia Rogelio Robaina Amalia Sotoca Carmen Vallejo german Valtuena Felipe Counago Department of Radiation Oncology Hospital del MarBarcelona 08003Spain Radiation Oncology Research Group Hospital Del Mar Medical Research InstitutionBarcelona 08003Spain Department of Experimental and Health Sciences Pompeu Fabra UniversityBarcelona 08003Spain Department of Radiation Oncology Thoracic Malignancies UnitHospital Duran i Reynals.ICOL´Hospitalet de LLobregat 08908Spain Department of Radiation Oncology Hospital Clinico de SalamancaSalamanca 37007Spain Department of Radiation Oncology ASCIRES Grupo BiomedicoValencia 46004Spain Department of Radiation Oncology Hospital Ruber InternacionalMadrid 28034Spain Department of Radiation Oncology Hospital Universitario Arnau de VilanovaLleida 25198Spain Department of Radiation Oncology Genesis Care-SpainSevilla 41092Spain Department of Radiation Oncology Hospital Universitario La PrincesaMadrid 28006Spain Department of Radiation Oncology Hospital Universitario Sant Joan de ReusReus 43204TarragonaSpain Department of Radiation Oncology Hospital Universitario Ramon y CajalMadrid 28034Spain Department of Radiation Oncology Hospital Clinico Universitario Lozano BlesaZaragoza 50009Spain Department of Radiation Oncology Hospital Universitario QuirónsaludMadrid 28223Spain Department of Radiation Oncology Hospital La LuzMadrid 28003Spain Department of Clinical Universidad EuropeaMadrid 28670Spain

Non-small cell lung cancer(NSCLC) is a heterogeneous disease accounting for approximately 85% of all lung cancers. Only 17% of patients are diagnosed at an early stage. Treatment is multidisciplinary and radiotherapy plays a key role in all stages of the disease. More than 50% of patients with NSCLC are treated with radiotherapy(curative-intent or palliative). Technological advancesincluding highly conformal radiotherapy techniques, new immobilization and respiratory control systems, and precision image verification systems-allow clinicians to individualize treatment to maximize tumor control while minimizing treatment-related toxicity. Novel therapeutic regimens such as moderate hypofractionation and advanced techniques such as stereotactic body radiotherapy(SBRT) have reduced the number of radiotherapy sessions. The integration of SBRT into routine clinical practice has radically altered treatment of early-stage disease. SBRT also plays an increasingly important role in oligometastatic disease. The aim of the present guidelines is to review the role of radiotherapy in the treatment of localized, locally-advanced, and metastatic NSCLC. We review the main radiotherapy techniques and clarify the role of radiotherapy in routine clinical practice. These guidelines are based on the best available evidence. The level and grade of evidence supporting each recommendation is provided.

关键词： Radiotherapy Non-small cell lung cancer Guidelines Stereotactic radiation therapy Hypofractionated radiation Oligometastasis