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Beyond the RPA and GW methods with adiabatic xc-kernels for accurate ground state and quasiparticle energies

npj Computational Materials 2019年第1期5卷 202-224页

作者： Thomas Olsen christopher E.Patrick Jefferson E.Bates Adrienn Ruzsinszky Kristian s.Thygesen Computational Atomic-scale Materials Design(CAMD) Department of PhysicsTechnical University of DenmarkKongens LyngbyDenmark Department of Physics University of WarwickCoventry CV47ALUK A.R.smith Department of Chemistry and Fermentation sciences Appalachian State UniversityBooneNC 28607USA Department of Physics Temple UniversityPhiladelphiaPA 19122USA Center for Nanostructured Graphene(CNG) Department of PhysicsTechnical University of DenmarkKongens LyngbyDenmark

We review the theory and application of adiabatic exchange–correlation(xc)-kernels for ab initio calculations of ground state energies and quasiparticle excitations within the frameworks of the adiabatic connection fluctuation dissipation theorem and Hedin’s equations,*** different xc-kernels,which are all rooted in the homogeneous electron gas,are introduced but hereafter we focus on the specific class of renormalized adiabatic kernels,in particular the rALDA and *** kernels drastically improve the description of short-range correlations as compared to the random phase approximation(RPA),resulting in significantly better correlation *** effect greatly reduces the reliance on error cancellations,which is essential in RPA,and systematically improves covalent bond energies while preserving the good performance of the RPA for dispersive *** quasiparticle energies,the xc-kernels account for vertex corrections that are missing in the GW *** this context,we show that the short-range correlations mainly correct the absolute band positions while the band gap is less affected in agreement with the known good performance of GW for the *** renormalized xc-kernels offer a rigorous extension of the RPA and GW methods with clear improvements in terms of accuracy at little extra computational cost.

关键词： adiabatic kernels quasi

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Numerical prediction of the frictional losses in sliding bearings during start-stop operation

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Friction 2021年第3期9卷 583-597页

作者： Florian KÖNIG christopher sOUs Georg JACOBs Institute for Machine Elements and systems Engineering Rheinisch-Westfälische Technische Hochschule Aachen UniversitySchinkelstraße 10Aachen 52062Germany

With the increased use of automotive engine start-stop systems,the numerical prediction and reduction of frictional losses in sliding bearings during starting and stopping procedures has become an important *** engineering practice,numerical simulations of sliding bearings in automotive engines are performed with statistical asperity contact models with empirical values for the necessary surface *** aim of this study is to elucidate the applicability of these approaches for the prediction of friction in sliding bearings subjected to start-stop *** this purpose,the friction performance of sliding bearings was investigated in experiments on a test rig and in transient mixed elasto-hydrodynamic simulations in a multi-body simulation environment(mixed-EHL/MBs).In mixed-EHL/MBs,the extended Reynold’s equation with flow factors according to Patir and Cheng has been combined on the one hand with the statistical asperity contact model according to Greenwood and Tripp and on the other hand with the deterministic asperity contact model according to *** detailed comparison of simulation and experimental results clarifies that the application of statistical asperity contact models with empirical values of the necessary inputs leads to large deviations between experiment and *** actual distribution and position of surface roughness,as used in deterministic contact modelling,is necessary for a reliable prediction of the frictional losses in sliding bearings during start-stop operation.

关键词： sliding bearing friction wearing-in contact model,mixed elasto-hydrodynamic simulation

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Optimization and kinetic studies for enzymatic hydrolysis and fermentation of colocynthis vulgaris shrad seeds shell for bioethanol production

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Journal of Bioresources and Bioproducts 2021年第1期6卷 45-64页

作者： Igwilo christopher Nnaemeka Egbuna samuel O Onoh Maxwell I Asadu OChristain Onyekwulu Chinelo s Department of science Laboratory Technology Federal College of AgricultureP.M.BIshiaguEbonyi StateNigeria Department of Chemical Engineering Enugu state University of science and Technology (ESUT)Nigeria Gregory University Uturu PMB 1012 Abia State Nigeria

The key process parameters for the hydrolysis and fermentation of Colocynthis vulgaris shrad seeds shell(CVsss)were optimized using the Box-Behnken Design(BBD)of Response surface Methodology(RsM).Kinetic study was also carried *** proximate analysis of the CVsss was done by the method of the Association of Organic and Applied Chemistry(AOAC).Enzymatic hydrolysis was experimented by using Aspergillus Niger as a crude enzyme isolated from soil at sawdust dump site and screened for cellulosic *** that affected the hydrolysis of the CVsss were screened by using the Greco-Latin square design of ***,for saccharomyces cerevisiae,factors that affected the fermentation of the CVsss were screened by using the same Greco-Latin square design of ***,the result of the proximate analysis revealed that the CVsss had 73.54%cellulose which could be converted to *** was established that temperature,pH and time had significant effect on hydrolysis,while the optimum results were obtained at 46.8℃,3.32 d,5.68 and 59.87%for temperature,time,pH and glucose yield,***,yeast dosage,pH and time had significant effect on fermentation,while the optimum results from optimization were found to be 33.58℃,7.0,3.55 d,1.65 g per 50 mL and 25.6%for temperature,pH,time,yeast dosage and ethanol yield,*** kinetics of both the enzymatic hydrolysis and fermentation agreed with the Michealis-Menten kinetic model with the correlation coefficients(R^(2))of 0.9708 and 0.8773,***,from the error analysis,the experimental and predicted values had a very good relationship as described by Michaelis-Menten model.

关键词： Ethanol Melon(Egusi)seed shell Hydrolysis Fermentation Optimization Kinetics

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A Time to Remember:Neural Insights into Rapid Updating of Timed Behaviors

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Neuroscience Bulletin 2023年第4期39卷 699-702页

作者： christopher Howard Patrick simen Neuroscience Department Oberlin CollegeOberlinOH44074USA

Processing temporal information is a critical brain function necessary for decision-making and *** timing,or processing of time intervals on the scale of seconds to minutes,is essential for associative learning,sensorimotor processing,and optimal foraging[1]and many neuropsychiatric illnesses including Parkinson's Disease,Huntington's Disease,and schizophrenia involve impaired interval timing.

关键词： Huntington impaired dating

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Adventures and lessons of an American biochemist in China

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Protein & Cell 2011年第8期2卷 601-603页

作者： christopher J.Vavricka CAs Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

It’s very interesting how events often lead up to each other seemingly by chance,but appear almost perfectly planned out when looking *** the past two years,I have worked as an International Young scientist Research Fellow at the Institute of Microbiology,Chinese Academy of sciences in Beijing,*** people ask me,especially Chinese graduate students,why an American would choose to come to China as a postdoctoral researcher.

关键词： looking doctor perfectly

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Transplanting neural progenitors to build a neuronal relay across the injured spinal cord

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Neural Regeneration Research 2014年第12期9卷 1173-1176页

作者： christopher Haas Itzhak Fischer Drexel University College of Medicine Department of Neurobiology & Anatomy

Cellular transplantation for repair of spinal cord injury is a prom- ising therapeutic strategy that includes the use of a variety of neural and non-neural cells isolated or derived from embryonic and adult tissue as well as embryonic stem cells and induced plu- ripotent stem cells. In particular, transplants of neural progenitor cells （NPCs） have been shown to limit secondary injury and scar formation and create a permissive environment in the injured spinal cord through the provision of neurotrophic molecules and growth supporting matrices that promote growth of injured host axons. Importantly, transplants of NPC are unique in their poten- tial to replace lost neural cells - including neurons, astrocytes,

关键词： Transplanting neural progenitors to build a neuronal relay across the injured spinal cord CsPG NPC GRP

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Pediatric inflammatory bowel disease

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World Journal of Gastroenterology 2006年第20期12卷 3204-3212页

作者： Karen A Diefenbach christopher K Breuer Department of surgery Yale University school of Medicine Division of Pediatric Surgery330 Cedar StreetRm. 132 FMBNorth HavenCT 06520United States

Inflammatory bowel disease is an important cause of gastrointestinal pathology in children and adolescents. The incidence of pediatric inflammatory bowel disease is increasing; therefore, it is important for the clinician to be aware of the presentation of this disease in the pediatric population. Laboratory tests, radiology studies, and endoscopic procedures are helpful in diagnosing inflammatory bowel disease and differentiating between Crohn＇s disease and ulcerative colitis. Once diagnosed, the goal of medical management is to induce remission of disease while minimizing the side effects of the medication. specific attention needs to be paid to achieving normal growth in this susceptible population. surgical management is usually indicated for failure of medical management, complication, or malignancy. Algorithms for diagnostic evaluation and treatment of pediatric inflammatory bowel disease are presented. The specific psychosocial issues facing these patients are also discussed in this review as are the future goals of research in the complex problem of pediatric inflammatory bowel disease.

关键词： Pediatric Inflammatory bowel Ulcerative colitis Crohn's disease

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Microstructural banding of directed energy deposition-additively manufactured 316L stainless steel

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Journal of Materials science & Technology 2021年第10期69卷 96-105页

作者： Yoon Hwa christopher s.Kumai Thomas M.Devine Nancy Yang Joshua K.Yee Ryan Hardwick Kai Burgmann Department of Materials science and Engineering University of CaliforniaBerkeleyCA94720USA sandia National Laboratory LivermoreCA.94551USA

The microstructures of 316L stainless steel created by rapid solidification are investigated by comparing the similar microstructures of individual hatches of directed energy deposition additive manufacturing(DED-AM)and those of single,laser surface-melted tracks formed on a solid *** recoil pressure,which is exponentially dependent on the laser beam power density,induces convection of the melt pool,which causes formation of microstructural bands in the as-solidified *** microstructural bands are associated with changes in the chromium concentration and are a significant component of the inhomogeneous microstructure of DED-AM.

关键词： Additive manufacturing Directed energy deposition stainless steel Rapid solidification Recoil pressure Microstructure

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Convergent evolution of brain morphology and communication modalities in lizards

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Current Zoology 2015年第2期61卷 281-291页

作者： christopher D. ROBIN.sON Michael s. PATTON Britmey M. ANDRE Michele A. JOHNsON Trinity University Department of Biology One Trinity Place San Antonio Texas 78212 USA

Animals communicate information within their environments via visual, chemical, auditory, and/or tactile modalities. The use of each modalityis generally linked to particular brain regions, but it is not yet known whether the cellular morphology of neurons in these regions has evolved in association with the relative use of a *** investigated relationships between the behavioral use of communication modalities and neural morphologies in six lizard species. Two of these species （Anolis carol# nensis and Leiocephalus carinatus） primarily use visual signals to communicate with conspecifics and detect potential prey, and two （Aspidoscelis gularis and scincella lateralis） communicate and forage primarily using chemical signals. Two other species （Hemidactylus turcicus and sceloporus olivaceus） use both visual and chemical signals. For each species, we performed beha- vioral observations and quantified rates of visual and chemical behaviors. We then cryosectioned brain tissues from 9-10 males of each species and measured the soma size and density of neurons in two brain regions associated with visual behaviors （the lat- eral geniculate nucleus and the nucleus rotundus） and one region associated with chemical behaviors （the nucleus sphericus）. With analyses conducted in a phylogenetic context, we found that species that performed higher rates of visual displays had a denser lateral geniculate nucleus, and species that used a higher proportion of chemical displays had larger somas in the nucleus sphericus. These relationships suggest that neural morphologies in the brain have evolved convergently in species with similar communication behaviors .

关键词： Brain Communication modality Lizards Pheromones social behavior Vision

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Using big data and machine learning to rank traffic signals in Tennessee

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Journal of Traffic and Transportation Engineering(English Edition) 2023年第5期10卷 918-933页

作者： christopher Winfrey Piro Meleby Lei Miao Department of Engineering Technology Middle Tennessee State UniversityMurfreesboroTN 37132USA

This paper discusses low-cost approaches capable of ranking traffic intersections for the purpose of signal *** extracted intersections that are comprised of multiple roads,defined by alphanumeric traffic message channel segment codes per international classification *** of these road segments includes a variety of metrics,including congestion,planning time index,and bottleneck ranking information provided by the Regional Integrated Transportation Information *** first approach was to use a ranking formula to calculate intersection rankings using a score between 0 and 10 by considering data for different times of the day and different days of the week,weighting weekdays more heavily than weekends and morning and evening commute times more heavily than other times of *** second method was to utilize unsupervised machine learning algorithms,primarily k-means clustering,to accomplish the intersection ranking *** first approach this by checking the performance of basic k-means clustering on our data *** then explore the ranking problem further by utilizing data provided by traffic professionals in the state of *** exploration involves using MATLAB to minimize the mean-squared error of intersection rankings to determine the optimum weights in the ranking formula based on a city’s professional *** then attempted an optimization of our weights via a brute-force search approach to minimize the distance from ranking formula results to the clustering *** the ranking information was aggregated into an online sQL database hosted by Amazon web services that utilized the PHP scripting language.

关键词： Unsupervised machine learning Clustering k-means Traffic signals

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