检索结果-南通市图书馆

Battery package design optimization for small electric aircraft

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2020年第11期33卷 2864-2876页

作者： Mingkai WANG Shuguang ZHANG Johannes DIEPOLDER florian HOLZAPFEL Institute of Aircraft Airworthiness Engineering School of Transportation Science and EngineeringBeihang UniversityBeijing 100083China Institute of Flight System Dynamics Department of Mechanical EngineeringTechnical University of MunichGarching D-85748Germany

The increasing gross weight of electric Unmanned Aerial Vehicle(UAV) poses a challenge in practical applications. The range and endurance of the electric UAV are limited by the fixed mass of the battery package. In this work, a design optimization method for the battery package topology of small electric UAV is proposed to enhance the performance. To improve the accuracy of the method, the dynamic battery model and simplified electric component models are *** models are utilized by the trajectory optimization method, which takes the dynamic characteristic into consideration to calculate the aircraft performance. The direct optimal control method is used for solving the trajectory optimization problem, and this method is tested on a small blended-wing-body electric aircraft. The test result shows that the range and energy-consumption are mainly influenced by the parallel topology of the battery package, while the flight time in climb phase is more sensitive to the series topology. It is deduced that the range-and energy-optimal design points can be considered concurrently in design optimization. The work proves the feasibility of integrating the trajectory optimization and battery package design.

关键词： Battery pack Design optimization Electric power system Trajectory optimization Unmanned Aerial Vehicle(UAV)

Unexpected encounter of the parasitic kind

在线全文

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2019年第11期11卷 904-919页

作者： Holly Matthews florian Noulin Centre for Applied Entomology and Parasitology School of Life Sciences Keele University

Both parasitology and stem cell research are important disciplines in their own *** are a real threat to human health causing a broad spectrum of diseases and significant annual rates morbidity and mortality *** cell research,on the other hand,focuses on the potential for regenerative medicine for a range of diseases including cancer and regenerative *** these two topics might appear distant,there are some“unexpected encounters”.In this review,we summarise the various links between parasites and stem ***,we discuss how parasites’own stem cells represent interesting models of regeneration that can be translated to human stem cell ***,we explore the interactions between parasites and host stem cells during the course of ***,we investigate from a clinical perspective,how stem cell regeneration can be exploited to help circumvent the damage induced by parasitic infection and its potential to serve as treatment options for parasitic diseases in the ***,we discuss the importance of screening for pathogens during organ transplantation by presenting some clinical cases of parasitic infection following stem cell therapy.

关键词： Stem cells Parasites Transplantation Therapeutic Host pathogen interactions

Numerical Visualization of Grease Flow in a Gearbox

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2023年第2期36卷 220-233页

作者： Hua Liu florian Dangl Thomas Lohner Karsten Stahl School of Engineering&Design Department of Mechanical EngineeringTechnical University of MunichGear Research Center(FZG)BoltzmannstraBe1585748 Garching near MunichGermany

Lubricating greases are widely used in *** gear drives and gearboxes with difficult sealing *** efficiency and heat balance of grease-lubricated gearboxes depend strongly on the lubrication mechanisms channeling and circulating,for which the grease flow is *** computational fluid dynamics opens up the possibility to visualize and understand the grease flow in gearboxes in more *** this study,a single-stage gearbox lubricated with an NLGI 1-2 grease was modeled by the finite-volume method to numerically investigate the fluid *** show that the rotating gears influence the grease sump only locally around the *** a low grease fill volume,the rotation of the gears is widely separated from the grease *** a high grease fill volume,a pronounced geargrease interaction results in a circulating grease flow around the *** simulated grease distributions show good accordance with high-speed camera recordings.

关键词： Lubrication Grease Transmission Gearbox Computational fluid dynamics

On fixity of arc-transitive graphs

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2021年第12期64卷 2603-2610页

作者： florian Lehner Primoz Potocnik Pablo Spiga Institute of Discrete Mathematics Graz University of TechnologyGraz 8010Austria Faculty of Mathematics and Physics University of LjubljanaLjubljana 1000Slovenia Dipartimento di Matematica Pura e Applicata University of Milano-BicoccaMilano 20126Italy

The relative xity of a permutation group is the maximum proportion of the points xed by a non-trivial element of the group,and the relative xity of a graph is the relative xity of its automorphism group,viewed as a permutation group on the vertex-set of the *** prove in this paper that the relative xity of connected 2-arc-transitive graphs of a xed valence tends to 0 as the number of vertices grows to in *** prove the same result for the class of arc-transitive graphs of a xed prime valence,and more generally,for any class of arc-transitive locally-L graphs,where L is a xed quasiprimitive graph-restrictive permutation group.

关键词： permutation group xity minimal degree graph automorphism group vertex-transitive arc-transitive xed points

Recording Spatially Resolved Plasma Parameters in Microwave-Driven Plasmas

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2013年第1期15卷 43-51页

作者： Gerhard FRANZ florian SCHAMBERGER Igor KRSTEV Stefan UMRATH Munich University of Applied Sciences Munich D-80335

In an almost cubical reactor 90 1 in volume which is intended to deposit organic polymers by plasma-enhanced chemical vapor deposition （PECVD）, microwave power is coupled into the volume via a quartz window which extends to approximately 1/10 of the sidewall area. Since the plasma is excited locally, plasma parameters like electron temperature and plasma density are expected to exhibit a spatial variation. The compilation of these plasma quantities has been accomplished with a bendable single Langmuir probe. To isolate the tungsten wire against its grounded housing tube, it was coated with polyparylene. After having compared this construction with our Langmuir probe, which has been now in use for more than a decade, we have taken data of more than half the volume of the reactor with argon and have found a definitive radial inhomogenity for all plasma parameters. To investigate whether this conduct can be determined applying optical emission spectroscopy, we improved our spectrometer which had been used for endpoint detection purposes and plasma diagnostics in chlorine-containing ambients where we could detect also a spatial dependence. This behavior is discussed in terms of Lieberman＇s global model.

关键词： high frequency and RF discharges optical measurements electric and mag-netic measurements

Ischemia and reperfusion injury of the spinal cord:experimental strategies to examine postischemic paraplegia

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2016年第3期11卷 414-415页

作者： florian Simon Alexander Oberhuber Clinic for Vascular-and Endovascular Surgery Heinrich-Heine-University

Thoracoabdominal aortic replacement,necessary in case of injuries,aneurysms and dissections,shows a high complication rate as a consequence of the perioperative ischemia/reperfusion-sequence（I/R）.Clamping above and below the lesion leads to the spinal cord suffering from *** times of less than 30 minutes show only a small risk of neurological deficit,

关键词： deficit minutes neurological replacement injuries suffering consequence longer thoracic subsequent

Smooth free-cycle dynamic soaring in unspecified shear wind via quadratic programming

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2022年第7期35卷 19-29页

作者： Haichao HONG Benedikt GRüTER Patrick PIPREK florian HOLZAPFEL Institute of Flight System Dynamics Technical University of MunichGarching D-85748Germany

Harvesting wind energy is promising for extending long-endurance flights,which can be greatly facilitated by a flight technique called dynamic *** presented study is concerned with generating model-based trajectories with smooth control histories for dynamic soaring maneuvers exploiting wind *** desired smoothness is achieved by introducing a trigonometric series parameterization for the controls,which are formulated with respect to the normalized ***,the periodicity of the trigonometric functions is leveraged to facilitate the connection of cycles and streamline the problem *** relying on a specified wind profile,a freefinal-time quadratic programming-based control strategy is developed for the online correction of the flight trajectory,which requires only the instant wind *** and online numerical studies show the trade-off to achieve the smoothness and demonstrate the effectiveness of the proposed method in a varying wind field.

关键词： Dynamic soaring Optimal control Quadratic programming Trajectory generation Trigonometric series

Simplified modeling of electromagnets for dynamic simulation of transient effects for a synchronous electric motor

在线全文

学校读者我要写书评

暂无评论

International Journal of Mechanical System Dynamics 2021年第1期1卷 89-95页

作者： florian Bechler Julius Kesten florian Wittemann Frank Henning Martin Doppelbauer Peter Eberhard Institute of Engineering and Computational Mechanics University of StuttgartStuttgartGermany Institute of Electrical Engineering Karlsruhe Institute of Technology(KIT)KarlsruheGermany Institute of Vehicle System Technology Karlsruhe Institute of Technology(KIT)KarlsruheGermany

This study aims to show an approach for the dynamic simulation of a synchro-nous *** magnetic forces in the air gap are calculated efficiently using simplified approaches without neglecting important *** the modeling of the magnetic forces,an equivalent magnetic circuit is constructed in which the magnetic saturation and the leakage flux are taken into account and coupled with the electrical circuit at the *** calculated magnetic forces are then passed to a mechanical model of the *** with a predefinable load torque,the resulting motor rotation and the forces in the bearings are *** presented model is then investigated in a small *** novel ap-proach is intended to provide a method of calculating dynamically the forces transmitted from the shaft to the motor housing and to create the basis for evaluating electric motors for vibrations,noise,and harshness under varying loads and input voltages.

关键词： dynamic simulation electromagnet electromagnet modeling magnetomotive forces

Theme Park Metatexts:An Aesthetics of Inclusion and Exclusion

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 Foreign Languages and Cultures 2019年第1期3卷 1-10页

作者： florian Freitag Johannes Gutenberg University Mainz

This article uses the examples of guide maps,so-called autothemed rides,and apps to examine the aesthetics of theme park metatexts,that is,medial representations of theme parks or parts thereof that are produced by the parks themselves and that serve as a medial interface between the park landscape and its *** theme park metatexts have frequently been employed as sources in theme park research,but have only very rarely been figured as objects of research *** on Lukas’s description of theme parks’representational strategies as a“politics of inclusion/exclusion,”the essay argues that theme park metatexts stress certain aspects of the park while deemphasizing others,and thus have a major impact on the way visitors anticipate,experience,and remember the *** applies to more“traditional”forms of metatexts such as printed guide maps,which are handed out for free to theme park visitors,to“autothemed”rides,in which the theme park represents itself in the medium of the theme park ride,but especially to theme park apps,which not only further intensify the“politics of exclusion”of,for example,guide maps,but also involve the visitor in their selection processes.

关键词： theme parks Disney popular culture apps cartography