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Effect of hot rolling on microstructure and properties of the ZEK100 alloy

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Journal of Magnesium and Alloys 2019年第1期7卷 27-37页

作者： Amjad Javaid frank Czerwinski CanmetMATERIALS 183 Longwood Road SouthHamiltonOntario L8P 0A5Canada

Attempts to expand manufacturing capabilities of magnesium-based sheet materials are *** as-cast ZEK100(Mg-1.2Zn-0.35Zr-0.17Nd,in wt%)magnesium alloy was subjected to hot rolling at temperatures from 350℃to 450℃using the laboratory 50 ton reversible mill with preheated rolls to manufacture the 1.5-1.7 mm thick *** rolling temperature affected the sheet properties and an increase in the rolling temperature from 250 to 450℃caused reduction of tensile strength from 257 to 228 MPa ac-companied by a reduction in tensile yield stress from 237 to 185 *** the same time,the alloy elongation increased from 17 to 21%.For the same rolling temperature range,the compressive strength reduced from 418 to 351 *** post-rolling annealing at 450℃led to reduction of both tensile and compressive properties with the largest changes corresponding to the rolling temperature of 350°*** correlation between the alloy grain size after rolling and the sheet properties was established where a reduction in grain size was accompanied by an increase of both the tensile/compressive strength and yield *** on Hall-Petch relationship and an average grain size the correlation developed in this study may be used as the prediction model for properties of the hot rolled magnesium *** results are discussed in terms of recent developments in magnesium sheet alloys and the vital role played in this process by rare earth elements.

关键词： Magnesium alloys Hot deformation Microstructure Rare earths Sheet rolling

Flow frictional characteristics of microencapsulated phase change material suspensions flowing through rectangular minichannels

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Science China(Technological Sciences) 2006年第4期49卷 445-456页

作者： frank Dammel Peter Stephan Chair of Technical Thermodynamics Darmstadt University of Technology Germany

An experimental investigation was conducted on the laminar flow frictional characteristics of suspensions with microencapsulated phase change material (MEPCM) in water flowing through rectangular copper minichannels. The MEPCM was provided at an average particle size of 4.97 μm, and was mixed with distilled water to form suspen- sions with various mass concentrations ranging from 0 to 20%. The experiment was per- formed to explore the effect of MEPCM mass concentration on friction factor and pressure drop in the minichannels. The Reynolds number ranged from 200 to 2000 to provide laminar and transitional flows. It was found that the experimental data for the suspensions with 0 and 5% concentration agree well with the existing theoretical data for an incom- pressible, fully developed, laminar Newtonian flow. For the suspensions with mass con- centrations higher than 10%, there is an obvious increase in friction factor and pressure drop in comparison with laminar Newtonian flow.

关键词： microencapsulated phase change material suspension, friction factor, rectangular minichannel.

Aerosol distribution and efficacy in a commercial food warehouse

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Insect Science 2008年第2期15卷 133-140页

作者： frank H. Arthur USDA-ARS Grain Marketing and Production Research Center Manhattan Kansas USA

A series of field trials were conducted in a commercial food storage facility to evaluate exposure of stored-product insects to aerosol formulations of synergized pyrethrins and the insect growth regulator methoprene. When adults of tribolium castaneum （Herbst）, the red flour beetle, and tribolium confusum （Jacqueline DuVal）, the confused flour beetle were exposed with and without a food source to synergized pyrethrin aerosol, there was no difference in adult mortality with respect to availability of food at either 7 or 14 days after exposure （P≥0.05）. However, mortality was lower in T. confusum （40.4% and 79.3% with flour at 7 and 14 days, 38.9% and 84.8% without flour at 7 and 14 days） compared to T. castaneum （96.5% and 99.8% with flour at 7 and 14 days, 91.0% and 98.7% without flour at 7 and 14 days）. Few late-stage larvae and pupae of either species exposed to the pyrethrin aerosol emerged as adults. In tests with methoprene aerosol, adult emergence of exposed 3- and 4-week-old larvae of T. confusum was less than 2%. Only 0.3% of 4-week-old larvae of T. castaneum exposed in open and obstructed areas emerged as adults. Emergence of adults from eggs of Plodia interpunctella （Hubner）, the Indianmeal moth, embedded in culture media and exposed to the methoprene aerosol was 13.2%±3.5%. Results show that the aerosols evaluated in our study could give effective control of some of the major storedproduct insect pests in commercial food storage facilities, and may offer an alternative to fumigation.

关键词： aerosols control methoprene Plodia pyrethrin tribolium

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TeV astronomy

Frontiers of physics 2013年第6期8卷 714-747页

作者： frank M. Rieger Max-Planck-Institut fiir Kernphysik P.O. Box 103980 69029 Heidelberg Germany Institut de Ciencies de L'Espai (IEEC-CSIC) Campus UAB Torte C5 08193 Bellaterra Spain Dublin Institute for Advanced Studies 31 Fitzwilliam Place Dublin 2 Ireland European Associated Laboratory for Gamma-Ray Astronomy jointly supported by CNRS and MPG

With the successful realization of the current-generation of ground-based detectors, TeV Astronomy has entered into a new era. We review recent advances in VHE astronomy, focusing on the potential of Imaging Atmospheric Cherenkov Telescopes （IACTs）, and highlight astrophysical implications of the results obtained within recent years.

关键词： TeV astronomy gamma-rays Cherenkov telescopes high-energy astrophysics

Hyperbolic L_2-modules with Reproducing Kernels

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Acta Mathematica Sinica,English Series 2006年第3期22卷 935-944页

作者： David EELPODE frank SOMMEN Ghent University Department of Mathematical AnalysisClifford Research GroupB-9000 GentBelgium

In this paper, the Dirac operator on the Klein model for the hyperbolic space is considered. A function space containing L2-functions on the sphere S^m-1 in R^m, which are boundary values of solutions for this operato... 详细信息

关键词： Hyperbolic space Clifford analysis Cauchy transform Lie sphere

Quantum Algorithm for Approximating Maximum Independent Sets

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Chinese Physics Letters 2021年第3期38卷 17-21页

作者： Hongye Yu frank Wilczek Biao Wu Department of Physics and Astronomy Stony Brook UniversityStony BrookNY 11794USA Center for Theoretical Physics Massachusetts Institute of TechnologyCambridgeMassachusetts 02139USA D.Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China Wilczek Quantum Center School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Department of Physics Stockholm UniversityStockholm SE-10691Sweden Department of Physics and Origins Project Arizona State UniversityTempe AZ 25287USA International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

We present a quantum algorithm for approximating maximum independent sets of a graph based on quantum non-Abelian adiabatic mixing in the sub-Hilbert space of degenerate ground states,which generates quantum annealing in a secondary *** both sparse and dense random graphs G,numerical simulation suggests that our algorithm on average finds an independent set of size close to the maximum size α(G) in low polynomial *** best classical algorithms,by contrast,produce independent sets of size about half of α(G)in polynomial time.

关键词： quantum polynomial Independent

Aspects of surface and environment protection in german mining areas

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Mining Science and Technology 2009年第5期19卷 615-619页

作者： frank Otto Technische Fachhochschule Georg Agricola zu Bochum University of Applied Sciences

Hard coal mining in the german Ruhr district has a tradition of more than 200 years. Starting in the south near the river Ruhr with mining of seams near to the surface, mining wandered to the north with coal seams deeper and deeper. In the same way all environmental effects of mining wandered from south to north, as there are abandoned mining sites, contaminated areas, burning mining dumps, subsided areas and gas accesses at day ground. This all happened in a very high populated area with more than four million inhabitants. Therefore germany has a long tradition in solving environmental problems of mining activities. The very good interaction of mine authority, mining companies and the mine workers’ union is the main reason why the problems of decreasing mining activities in germany were solved without economic, environmental or social hazards.

关键词： abandoned mining sites contaminated areas subsidence burning mining dumps gas accesses at day ground

Membrane processes for water recovery and wastewater treatment in the food industry

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Journal of Harbin Institute of Technology(New Series) 2012年第1期19卷 75-78页

作者： frank Lipnizki Alfa Laval Copenhagen Business Centre MembranesMaskinvej 52860 SborgDenmarkfrank

Despite the efforts to reduce its water consumption,the food industry still requires large amounts of water. Membrane processes have established themselves in the food industry at the beginning of the water loop for preparation of the intake water and at the end water loop for recovery and final treatment of the water. The focus of this paper is on two application studies related to water recovery and water treatment in the food industry. The first study is on water recovery from tank washing water in customized liquid sugar production. During the washing of the tanks,sweet water with 1°- 5° Brix sugars is produced which is equivalent to a COD of 5000 - 25000 mg/L. By reverse osmosis,this sweet water can be separated into a sugar-free permeate for recycling and a concentrate with more than 20° Brix,which can be utilized as animal feed. The second study is on the effluent from production of modified potato starch,which is contaminated with spirochete bacteria resulting in problems in the wastewater treatment plant. By installing a membrane bioreactor,not only is this problem overcome but the general quality of the water at the discharge of the plant is improved. Overall,this paper demonstrates that membrane processes have a large potential in the water recovery and wastewater treatment in the food industry.

关键词： Food industry membrane bioreactor sweet water starch industry

A Comprehensive Review of Redirected Walking Techniques:Taxonomy,Methods,and Future Directions

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Journal of Computer Science & Technology 2022年第3期37卷 561-583页

作者： Yi-Jun Li frank Steinicke Miao Wang State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang UniversityBeijing 100191China Department of Informatics Universität HamburgHamburg 20146Germany Peng Cheng Laboratory Shenzhen 518055China

Virtual reality(VR)allows users to explore and experience a computer-simulated virtual environment so that VR users can be immersed in a totally artificial virtual world and interact with arbitrary virtual ***,the limited physical tracking space usually restricts the exploration of large virtual spaces,and VR users have to use special locomotion techniques to move from one location to *** these techniques,redirected walking(RDW)is one of the most natural locomotion techniques to solve the problem based on near-natural walking *** core idea of the RDW technique is to imperceptibly guide users on virtual paths,which might vary from the paths they physically walk in the real *** a similar way,some RDW algorithms imperceptibly change the structure and layout of the virtual environment such that the virtual environment fits into the tracking *** this survey,we first present a taxonomy of existing RDW *** on this taxonomy,we compare and analyze both contributions and shortcomings of the existing methods in detail,and find view manipulation methods offer satisfactory visual effect but the experience can be interrupted when users reach the physical boundaries,while virtual environment manipulation methods can provide users with consistent movement but have limited application ***,we discuss possible future research directions,indicating combining artificial intelligence with this area will be effective and intriguing.

关键词： virtual reality locomotion redirected walking