检索结果-南通市图书馆

High Power Laser Science and Engineering 2015年第3期3卷 20-27页

作者： D.T.Michel A.K.Davis W.Armstrong r.bahr r.Epstein V.N.Goncharov M.Hohenberger I.V.Igumenshchev r.Jungquist D.D.Meyerhofer P.B.radha T.C.Sangster C.Sorce D.H.Froula Laboratory for Laser Energetics University of Rochester

Self-emission x-ray shadowgraphy provides a method to measure the ablation-front trajectory and low-mode nonuniformity of a target imploded by directly illuminating a fusion capsule with laser beams. The technique uses time-resolved images of soft x-rays(>1 ke V) emitted from the coronal plasma of the target imaged onto an x-ray framing camera to determine the position of the ablation front. Methods used to accurately measure the ablation-front radius(δ r= ±1.15 μm), image-to-image timing(δ( t)= ±2.5 ps) and absolute timing(δt= ±10 ps) are *** averaging of the images provides an average radius measurement of δ( rav)= ±0.15 μm and an error in velocity of δV / V= ±3%. This technique was applied on the Omega Laser Facility [Boehly et al., Opt. Commun. 133, 495(1997)] and the National Ignition Facility [Campbell and Hogan, Plasma Phys. Control. Fusion 41, B39(1999)].

关键词： low mode nonuiformity nuclear fusion self-emission shadowgraphy shell trajectory

Predictions of decreased surface roughness after shot peening using controlled media dimensions

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第23期58卷 120-129页

作者： Siavash Ghanbari David F.bahr School of Materials Engineering Purdue UniversityWest LafayetteIN47907USA

Shot peening induces residual compressive stresses on metallic substrates, often used to decrease fatigue crack growth. The relationship between surface roughness and the magnitude of the stress can be affected by peening media size or the extent of peening. Generally, an ideal condition from shot peening would be a high compressive residual stress and a low surface roughness, but these tend to be inversely *** study proposes a method for decreasing roughness and increasing residual stress concurrently using a distribution of shot sizes in a single shot peening passage based on finite element modeling that has been calibrated using by experimental results. Numerical models predict mixed shot sizes will create a smoother surface than using monodispersed shot at 100 % coverage. The residual stress profile for mixed shot sizes showed a broad range of compressive residual stresses in comparison with the largest impact ball size. This newly proposed method can improve the surface quality and the extent of the compressive residual stresses in a single-shot peening passage.

关键词： Numerical analysis Shot peening roughness

A tunable ferroelectric based unreleased rF resonator

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2020年第1期6卷 1334-1340页

作者： Yanbo He Bichoy bahr Mengwei Si Peide Ye Dana Weinstein Purdue University West LafayetteINUSA Kilby Labs Texas InstrumentsDallasTXUSA

This paper introduces the first tunable ferroelectric capacitor(FeCAP)-based unreleased rF MEMS resonator,integrated seamlessly in Texas Instruments’130 nm Ferroelectric rAM(FerAM)*** designs presented here are monolithically integrated in solid-state CMOS technology,with no post-processing or release step typical of other MEMS *** array of FeCAPs in this complementary metal-oxide-semiconductor(CMOS)technology’s back-end-of-line(BEOL)process were used to define the acoustic resonance cavity as well as the electromechanical *** achieve high quality factor(Q)of the resonator,acoustic waveguiding for vertical confinement within the CMOS stack is studied and *** design considerations are discussed to obtain lateral confinement and suppression of spurious *** FeCAP resonator is demonstrated with fundamental resonance at 703 MHz and Q of *** gives a frequency-quality factor product f·Q=7:11×10^(11) which is 1.6×higher than the most state-of-the-art Pb(Zr,Ti)O_(3)(PZT)*** to the ferroelectric characteristics of the FeCAPs,transduction of the resonator can be switched on and off by adjusting the electric *** this case,the resonance can be turned off completely at±0.3 V corresponding to the coercive voltage of the constituent FeCAP *** novel switchable resonators may have promising applications in on-chip timing,ad-hoc radio front ends,and chip-scale sensors.

关键词： resonator tunable switched

Fast and accurate surface normal integration on non-rectangular domains

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computational Visual Media 2017年第2期3卷 107-129页

作者： Martin bahr Michael Breuβ Yvain Quéau Ali Sharifi Boroujerdi Jean-Denis Durou Brandenburg Technical University Institute for MathematicsChair for Applied Mathematics Technical University Munich Universit'e de Toulouse IRIT

The integration of surface normals for the purpose of computing the shape of a surface in 3D space is a classic problem in computer vision. However,even nowadays it is still a challenging task to devise a method that is flexible enough to work on non-trivial computational domains with high accuracy, robustness,and computational efficiency. By uniting a classic approach for surface normal integration with modern computational techniques, we construct a solver that fulfils these requirements. Building upon the Poisson integration model, we use an iterative Krylov subspace solver as a core step in tackling the task. While such a method can be very efficient, it may only show its full potential when combined with suitable numerical preconditioning and problem-specific initialisation. We perform a thorough numerical study in order to identify an appropriate preconditioner for this *** provide suitable initialisation, we compute this initial state using a recently developed fast marching integrator. Detailed numerical experiments illustrate the benefits of this novel combination. In addition, we show on real-world photometric stereo datasets that the developed numerical framework is flexible enough to tackle modern computer vision applications.

关键词： surface normal integration Poisson integration conjugate gradient method preconditioning fast marching method Krylov subspace methods photometric stereo 3D reconstruction

THE SEPArATION AND DETErMINATION OF XANTHATES USING HIGH PErFOrMANCE LIQUID CHrOMATOGrAPHY

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 1991年第1期1卷 89-95页

作者： Zhou Chunshan bahr Albert Schwedt Georg Central South University of Technology Changsha 410083China Technical University of Clauslhal Clausthal-ZellerfeldGermany

Three HPLC methods for the separation and determination of xanthate mixtures are *** chromatographic behaviours,advantages and application ranges of various:methods have been discussed in detail.A calculation method for determining the results of individual xanthates from the complicated chromatographic peaks of xanthate mixtures is *** limits of detection are 0.15-2.0ng.

关键词： xanthate dixanthogen collector liquid chromatography

risk factors for hamstring injury in professional soccer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中华物理医学与康复杂志 2018年第11期40卷 820-820页

作者： van Dyk N Farooq A bahr r

BACKGrOUND AND OBJECTIVE In elite soccer play,hamstring injuries are the most common noncontact *** the evidence supporting the use of stretching exercises for the prevention of these injuries is limited,this study ex... 详细信息

关键词： hamstring injuries injury soccer professional

Changes of duplex parameters and splenic size in liver transplant recipients during a long period of observation

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第43期11卷 6787-6791页

作者： Bita Boozari Michael Gebel Mathias J bahr Michael P Manns Christian P Strassburg Joerg S Bleck J Klempnauer Bjoern Nashan Department of Gastroenterology Department of Visceral and Transplant Surgery Department of Transplant Surgery

AIM: To assess the changes of portal and arterial velocities, resistance index, spleen and liver size during a long observation period (13.7 years) after orthotopic liver transplantation (OLT).METHODS: Two hundred and sixty patients were recruited retrospectively for this study and divided into groups with defined time intervals after OLT. The cross-sectional changes of portal and arterial velocities,resistance index, spleen and liver size between the defined time intervals were studied. The complications detected by ultrasound were compared to gold standard ***: The mean values for liver size were all within the normal range. The splenic size decreased between the time intervals 100 and 1 000 d after OLT (t;P＜0.01).While portal and arterial flow velocities decreased up to 5.5 years (t; portal velocity P＜0.01, maximal systolic velocity P=0.05, maximal end diastolic velocity P＜0.01),rI increased during this interval (t:P＜0.01). Higher rIvalues were found in older patients (r = 0.24, P＜0.001).CONCLUSION: The arterial and portal velocities show adaptation processes continuing over the course of many years after OLT and are reported for the first time. The vascular complications detected by ultrasound occur mostly up to 100 d after OLT.

关键词： Ultrasound Color Doppler Liver transplantation Monitoring

Forbidden Fruit Tastes the Sweetest—A Study of Norwegians’ Consumption Pattern of Chocolate, Sweets, Salty Snacks, Soft Drinks and the Like

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 2012年第12期3卷 1619-1630页

作者： Annechen bahr Bugge randi Lavik National Institute for Consumer research (SIFO) Oslo Norway.

The theme of this study is eating and drinking patterns for products of which the health authorities want the Norwegian people to reduce their consumption. Although consumption development has shown positive trends over the past few years, Norwegians still have a much higher intake of such products than what is advisable. The study showed that only a small proportion had not eaten chocolate, sweets, sweet pastries, salty snacks etc. in the last seven days. Young people, men, people with low education and people living in households with children had the highest eating and drinking frequency of these kinds of products. Gender and age had the strongest impact on eating and drinking frequency. However, women had a higher eating rate of chocolate and sweets, and men had a higher eating and drinking frequency of salty snacks and sugary soda. People with low education had a considerably higher frequency of drinking sugary soda than people with high education. Among those who ate these products weekly, there were many who expressed that they would prefer to avoid such products, but that they were often tempted. Among those who ate these products a few times a month or less, few said that they did not like chocolate, sweets, etc. The main reason for having a relatively low eating and drinking frequency was that they perceived such products as unhealthy and fattening. Although there were only a few in the group of respondents who were concerned with healthy eating that had not eaten any of the listed products in the past seven days, this group had a significantly lower frequency of eating chocolate, sweets, etc. than the group that was not concerned with this. It was also clear that people who were health conscious to a greater extent limited eating of such products to the weekends and special occasions than those who were not. In order to succeed in reducing eating and drinking frequency of these products, it will be necessary to draw attention to product availability and s

关键词： Advertising Age Agency Class Consumption Food Cultural Codes Gender Health Marketing Nutritional Policy Pseudo Foods Societal Structures

Selective Pb^(2+) removal and electrochemical regeneration of fresh and recycled FeOOH

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 research 2023年第7期16卷 9352-9363页

作者： Lei Wang Lexane Deligniere Samantha Husmann regina Leiner Carsten bahr Shengjie Zhang Chaochao Dun Matthew M.Montemore Markus Gallei Jeffrey J.Urban Choonsoo Kim Volker Presser INM—Leibniz Institute for New Materials Campus D22Saarbrücken 66123Germany Department of Materials Science and Engineering Saarland UniversityCampus D22Saarbrücken 66123Germany Polymer Chemistry Saarland UniversityCampus C42Saarbrücken 66123Germany 4 GEH Wasserchemie GmbH&Co.KGAdolf-Köhne-Straße Osnabrück 49090 Germany Department of Chemical and Biomolecular Engineering Tulane UniversityNew OrleansLA 70118USA The Molecular Foundry Lawrence Berkeley National Laboratory BerkeleyBerkeleyCA 94720USA Saarene-Saarland Center for Energy Materials and Sustainability Campus C42Saarbrücken 66123Germany Department of Environmental Engineering with Institute of Energy/Environment Convergence Technologies Kongju National University1223-24 Cheonan-daeroCheonan-si 31080Republic of Korea Department of Future Convergence Engineering Kongju National University1223-24 Cheonan-daeroCheonan-si 31080Republic of Korea

Heavy metal pollution is a key environmental *** extracting heavy metals could accomplish water purification and resource recycling *** is a promising approach with a facile process,adaptability for the broad concentration of feed water,and high ***,the adsorption method faces challenges in synthesizing highperformance sorbents and regenerating adsorbents *** is an environmentally friendly sorbent with low-cost production on a large ***,the selectivity behavior and regeneration of FeOOH are seldom ***,we investigated the selectivity of FeOOH in a mixed solution of Co^(2+),Ni^(2+),and Pb^(2+)and proposed to enhance the capacity of FeOOH and regenerate it by using external *** charge,the FeOOH electrode shows a Pb^(2+)uptake capacity of 20 mg/*** applying a voltage of-0.2/+0.8 V,the uptake capacity increases to a maximum of 42 mg/g and the desorption ratio is 70%-80%.In 35 cycles,FeOOH shows a superior selectivity towards Pb^(2+)compared with Co^(2+)and Ni^(2+),with a purity of 97%±3%in the *** high selectivity is attributed to the lower activation energy for Pb^(2+)*** capacity retentions at the 5^(th)and the 35^(th)cycles are ca.80%and ca.50%,respectively,comparable to the chemical regeneration *** industrially exhausted granular ferric hydroxide as the electrode material,the system exhibits a Pb^(2+)uptake capacity of 37.4 mg/g with high *** work demonstrates the feasibility of regenerating FeOOH by charge and provides a new approach for recycling and upcycling FeOOH sorbent.

关键词： FeOOH electrochemical regeneration selective separation heavy metal ions

Effect of ultraviolet photofunctionalization of dental titanium implants on osseointegration

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 Zhejiang University-Science B(Biomedicine & Biotechnology) 2018年第7期19卷 525-534页

作者： Christian MEHL Matthias KErN Friederike NEUMANN Telse bahr Jorg WILTFANG Volker GASSLING Department of Prosthodontics Propaedeutics and Dental Materials Christian-Albrechts University at KielArnold-Heller-Straβe 16. 24105 Kiel Germany Private Practice Lassabeker Weg 3 24211 Lehmkuhlen Germany Department of Oral and Maxillofacial Surgery Christian-Albrechts University at Kiel Arnold-Heller-Straβe 16 24105 Kiel Germany

Objective： The aim of the current study was to evaluate the effect of ultraviolet（UV） photofunctionalization of dental titanium implants with exposure to the oral cavity on osseointegration in an animal model. Methods： Forty-eight titanium implants（Camlog~？ Conelog~？ 4.3 mmx9.0 mm） were placed epicrestally into the edentulous jaws of three minipigs and implant stability was assessed by measuring the implant stability quotient（ISQ）. Prior to implantation half of the implants were photofunctionalized with intense UV-light. After three months, the implants were exposed and ISQ was measured again. After six months of implant exposure, the minipigs were sacrificed and the harvested specimens were analyzed using histomorphometric, light, and fluorescence microscopy. Main results： Forty-two of 48 implants osseointegrated. The overall mean bone-implant contact area（BIC） was（64±22）%. No significant differences were found in BIC or ISQ value（multivariate analysis of variance（MANOVA）, P〉0.05） between implants with and without exposure to UV photofunctionalization. Conclusions： No significant effects were observed on osseointegration of dental titanium implants nine months after exposure of UV photofunctionalization.

关键词： Dental implant Osseointegration Photofunctionalization