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加氢催化剂活性对吸附和表面反应速率的影响

化学反应工程与工艺 1987年第1期3卷 10-23页

作者：陈诵英 J.M.smith b.J.McCoy 中国科学院山西煤炭化学研究所

α-甲基苯乙烯在三相浆化反应器中加氢的动态研究表明,催化剂还原温度对吸附平衡常数、吸附和表面反应速率系数有明显的影响。实验在全混浆化反应器中进行,温度为22℃,38℃和50℃,当还原温度从250℃增加到510℃时,PdCl2还原为 Pd 的 Pd... 详细信息

α-甲基苯乙烯在三相浆化反应器中加氢的动态研究表明,催化剂还原温度对吸附平衡常数、吸附和表面反应速率系数有明显的影响。实验在全混浆化反应器中进行,温度为22℃,38℃和50℃,当还原温度从250℃增加到510℃时,PdCl2还原为 Pd 的 Pd 分散度减小,从而使平衡吸附,吸附和表面反应速率系数均减小。吸附热和表面反应活化能分别为15.9和41.8KJ/mol,且不随还原温度而变。对于三个不同还原温度,其金属分散度的相对大小可从平衡吸附系数计算,发现其结果与 boitiaux 等的实验结果一致。

关键词：反应速率常数分散度还原温度反应速率系数 Pd 加氢催化剂吸附实验吸附平衡常数

Advances of drag-reducing surface technologies in turbulence based on boundary layer control

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Journal of Hydrodynamics 2015年第4期27卷 473-487页

作者： LUO Yuehao WANG Liguo GREEN Lork SONG Kenan WANG Liang smith Robert School of Engineering and Applied Science The George Washington University Division of Electricity Department of Engineering Sciences Uppsala University School of Engineering Boston University Department of Mechanical and Industrial Engineering Northeastern University Department of Mechanical Engineering University of Colorado at Boulder College of Applied Sciences and Technology Ball State University

Our living environment is surrounded by turbulence, which is also a concern of the global energy consumption and the greenhouse gas emission, and the viscous force on the solid-liquid/solid-gas interface is an important part of the turbulence. Reducing friction force in turbulence to the greatest extent is becoming an urgent issue to be resolved at present. In this paper, the various state-of-the-art approaches of drag-reducing and energy-saving technologies based on the boundary layer control are reviewed, focusing on the polymer drag reduction additives, the micro-morphology, the super-hydrophobic surface, the micro air bubbles, the heating wall, the vibrant flexible wall and the composite drag reduction methods. In addition, the mechanisms of different drag reductions based on the boundary layer control and the potential applications in fluid engineering are discussed. This paper aims not only to contribute to a better understanding of drag reduction mechanisms, but also to offer new perspectives to improve the current drag-reducing and energy saving technologies.

关键词： fluid drag reduction hydrodynamics energy saving turbulent flowing boundary layer control

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A bioactivity Versus Ethnobotanical Survey of Medicinal Plants from Nigeria, West Africa

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Natural Products and bioprospecting 2014年第1期4卷 1-19页

作者： Lydia L.Lifongo Conrad V.Simoben Fidele Ntie-Kang smith b.babiaka Philip N.Judson Chemical and bioactivity Information Centre Department of ChemistryFaculty of ScienceUniversity of BueaBueaCameroon Chemical and bioactivity Information Centre 22-23 Blenheim TerraceWoodhouse LaneLeeds LS29HDUK Chemical and bioactivity Information Centre Granary Wharf House2 Canal WharfLeeds LS115PYUK

Traditional medicinal practices play a key role in health care systems in countries with developing *** aim of this survey was to validate the use of traditional medicine within local Nigerian *** this review,we examine the ethnobotanical uses of selected plant species from the Nigerian flora and attempt to correlate the activities of the isolated bioactive principles with known uses of the plant species in African traditional ***-three(33)plant species were identified and about 100 out of the 120 compounds identified with these plants matched with the ethnobotanical uses of the plants.

关键词： African traditional medicine bioactivity Ethnobotany Medicinal plants Nigeria

Reverse mode switching of the random laser emission in dye doped liquid crystals under homogeneous and inhomogeneous electric fields

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Photonics Research 2016年第1期4卷 7-12页

作者： M.Shasti P.Coutino S.Mukherjee A.Varanytsia T.smith A.P.Luchette L.Sukhomlinova T.Kosa A.Munoz b.Taheri Alpha Micron Inc. Liquid Crystal Institute Kent State University

We report the observation of electric field induced random lasing in a dye doped liquid crystal system. This was achieved by using a liquid crystal host with negative dielectric anisotropy doped with laser dye PM 597 in a 75 μm cell with a homeotropic alignment layer. In the absence of an applied field, only amplified spontaneous emission was observed since the liquid crystal orientation was uniform. However, application of a field resulted in a fieldinduced planar-like configuration with local nonuniformity in liquid crystal orientation. This led to random lasing in the energized state(voltage greater than a transition threshold). The onset of lasing occurs by application of either a spatially homogenous or a spatially inhomogeneous electric field across the liquid crystal. The characteristics of the emission spectra as a function of different(i) dye concentration and(ii) applied voltage were investigated using nanosecond pulsed laser excitation at 532 nm. The effects of using an inhomogeneous field were compared to the use of a homogenous field and reported. It is shown that the spatial configuration can be used to alter the emission spectra of the system. The work is used to suggest a new configuration, referred to here as"reverse mode," for liquid crystal-based random lasers. This new configuration may provide additional avenues for their use in commercial devices.

关键词： mode Reverse mode switching of the random laser emission in dye doped liquid crystals under homogeneous and inhomogeneous electric fields

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Anti-onchocerca Metabolites from Cyperus articulatus:Isolation,In Vitro Activity and In Silico‘Drug-Likeness’

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Natural Products and bioprospecting 2014年第4期4卷 243-249页

作者： Jonathan Alunge Metuge smith b.babiaka James A.Mbah Fidele Ntie-Kang Godfred A.Ayimele Fidelis Cho-Ngwa ANDI Centre of Excellence Department of Biochemistry and Molecular BiologyFaculty of ScienceUniversity of BueaP.O.Box 63BueaCameroon Department of Chemistry Faculty of ScienceUniversity of BueaP.O.Box 63BueaCameroon Chemical and bioactivity Information Centre Chemistry DepartmentFaculty of ScienceUniversity of BueaP.O.Box 63BueaCameroon

The aims of this investigation were to isolate active ingredients from the roots/rhizomes of Cyperus articulatus used as herbal medicine in Cameroon for the treatment of human onchocerciasis and to assess the efficacy of the metabolites on the Onchocerca *** antifilarial activity was evaluated in vitro on microfilariae(Mfs)and adult worms of the bovine derived Onchocerca ochengi,a close relative of Onchocerca *** was assessed in vitro on monkey kidney epithelial *** structures of the active compounds were determined using spectroscopic methods and their drug-likeness evaluated using Lipinski *** secondary metabolites,AMJ1[containing mustakone(1)as the major component]and linoleic acid or(9Z,12Z)-octadeca-9,12-dienoic acid(2)were *** compounds were found to kill both the microfilariae and adult worms of *** in a dose dependent *** IC50s for AMJ1 were 15.7 lg/mL for Mfs,17.4 lg/mL for adult males and 21.9 lg/mL for adult female worms while for linoleic acid the values were,15.7 lg/mL for Mfs,31.0 lg/mL for adult males and 44.2 lg/mL for adult *** present report provides the first ever evidence of the anti-Onchocerca efficacy of AMJ1 and linoleic ***,these secondary metabolites may provide a lead for design and development of new antifilarial agents.

关键词： Cyperus articulates Linoleic acid Microfilariae Mustakone Onchocerca ochengi Onchocerca volvulus

Exploring ancestral phenotypes and evolutionary development of the mammalian middle ear based on Early Cretaceous Jehol mammals

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National Science Review 2021年第5期8卷 57-66页

作者： Fangyuan Mao Cunyu Liu Morgan Hill Chase Andrew K.smith Jin Meng Key Laboratory of Evolutionary Systematics of Vertebrates Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of Sciences CAS Center for Excellence in Life and Paleoenvironment Division of Paleontology American Museum of Natural History beipiao Pterosaur Museum of China 5. Microscopy and Imaging Facility American Museum of Natural History Earth and Environmental Sciences Graduate CenterCity University of New York

We report a new Cretaceous multituberculate mammal with 3 D auditory bones preserved. Along with other fossil and extant mammals, the unequivocal auditory bones display features potentially representing ancestral phenotypes of the mammalian middle ear. These phenotypes show that the ectotympanic and the malleus-incus complex changed notably during their retreating from the dentary at various evolutionary stages and suggest convergent evolution of some features to extant mammals. In contrast, the incudomalleolar joint was conservative in having a braced hinge configuration, which narrows the morphological gap between the quadroarticular jaw joint of non-mammalian cynodonts and the incudomalleolar articulations of extant mammals. The saddle-shaped and abutting malleus-incus complexes in therians and monotremes, respectively, could have evolved from the braced hinge joint *** evolutionary changes recorded in the Mesozoic mammals are largely consistent with the middle ear morphogenesis during the ontogeny of extant mammals, supporting the relation between evolution and development.

关键词： Cretaceous Jehol biota malleus-incus ectotympanic mammal evolution

A machine learning framework for damage mechanism identification from acoustic emissions in unidirectional SiC/SiC composites

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npj Computational Materials 2021年第1期7卷 1326-1335页

作者： C.Muir b.Swaminathan K.Fields A.S.Almansour K.Sevener C.smith M.Presby J.D.Kiser T.M.Pollock S.Daly Materials University of California-Santa BarbaraSanta BarbaraCAUSA Mechanical Engineering University of California-Santa BarbaraSanta BarbaraCAUSA NASA Glenn Research Center ClevelandOHUSA Materials Science and Engineering University of Michigan-Ann ArborAnn ArborMIUSA

In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is *** waveforms were generated by SiC/SiC ceramic matrix minicomposites(CMCs)loaded under uniaxial tension and recorded by four sensors(two models with each model placed at two ends).Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral *** cracking and fiber failure were identified based on the frequency information contained in the AE event they produced,despite the similar constituent elastic properties of the matrix and ***,the resultant identification of AE events closely followed CMC damage chronology,wherein early matrix cracking is later followed by fiber breaks,even though the approach is fully domain-knowledge ***,the partitions were highly precise across both the model and location of the sensors,and the partitioning was *** presented approach is promising for CMCs and other composite systems with elastically similar constituents.

关键词： composites damage mechanism

Systematic mechanism-orientated approach to chronic pancreatitis pain

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World Journal of Gastroenterology 2015年第1期21卷 47-59页

作者： Stefan AW bouwense Marjan de Vries Luuk TW Schreuder Soren S Olesen Jens b Frokjær Asbjorn M Drewes Harry van Goor Oliver HG Wilder-smith Pain and Nociception Neuroscience Research Group Department of SurgeryRadboud University Medical Center6500HB GelderlandThe Netherlands Department of Gastroenterology and Hepatology and Clinical Medicine Aalborg University Hospital9100 AalborgDenmark Center for Sensory-Motor Interaction Department of Health Science and TechnologyAalborg University9100 AalborgDenmark Department of Anaesthesiology Pain and Palliative MedicineRadboud University Medical Center6500HB GelderlandThe Netherlands

Pain in chronic pancreatitis(CP) shows similarities with other visceral pain syndromes(i.e.,inflammatory bowel disease and esophagitis),which should thus be managed in a similar *** causes of CP pain include increased intrapancreatic pressure,pancreatic inflammation and pancreatic/extrapancreatic ***,CP pain continues to be a major clinical *** is recognized that ongoing pain may induce altered central pain processing,e.g.,central sensitization or pro-nociceptive pain *** this is present conventional pain treatment targeting the nociceptive focus,e.g.,opioid analgesia or surgical/endoscopic intervention,often fails even if technically *** central nervous system pain processing is altered,specific treatment targeting these changes should be instituted(e.g.,gabapentinoids,ketamine or tricyclic antidepressants).Suitable tools are now available to make altered central processing visible,including quantitative sensory testing,electroencephalograpy and(functional) magnetic resonance *** techniques are potentially clinically useful diagnostic tools to analyze central pain processing and thus define optimum management approaches for pain in CP and other visceral pain *** present review proposes a systematic mechanism-orientated approach to pain management in CP based on a holistic view of the mechanisms *** research should address the circumstances under which central nervous system pain processing changes in CP,and how this is influenced by ongoing nociceptive input and *** we hope to predict which patients are at risk for developing chronic pain or not responding to therapy,leading to improved treatment of chronic pain in CP and other visceral pain disorders.

关键词： Chronic pancreatitis Pain Pain treatment Central sensitization Quantitative sensory testing Electroencephalograpy Magnetic resonance imaging

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biomedical and Environmental Sciences 2021年第9期34卷 734-738页

作者： James b.Hittner Folorunso O.Fasina Almira L.Hoogesteijn Renata Piccinini Dawid Maciorowski Prakasha Kempaiah Stephen D.smith Ariel L.Rivas Department of Psychology College of CharlestonCharlestonSouth CarolinaUnited States of America29424 Food and Agriculture Organization Dar es SalamTanzania&Department of Veterinary Tropical DiseasesUniversity of PretoriaSouth Africa0010 Human Ecology Centro de Investigación y de Estudios Avanzados(CINVESTAV)MéridaMéxico97133 Department of Veterinary Medicine University of MilanMilanItaly20122 Loyola University Medical Center ChicagoIllinoisUnited States of America60153 Institute for Resource Information Science College of AgricultureCornell UniversityIthacaUnited States of America14853 Center for Global Health Department of Internal MedicineMedical SchoolUniversity of New MexicoAlbuquerqueNew MexicoUnited States of America87131

The COVID-19 pandemic has wreaked havoc around the globe and caused significant disruptions across multiple domains[1].Moreover,different countries have been differentially impacted by COVID-19—a phenomenon that is d... 详细信息

关键词： Strongly COV Death

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