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Chaotic ray dynamics enables photonics with broadband light

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Science China(Physics,Mechanics & Astronomy) 2018年第1期61卷 78-79页

作者： Hailin Wang jens Nockel Department of Physics University of Oregon Eugene OR 97403 USA

Propagation of sound waves through reflections along a curved surface was first theoretically analyzed by Lord Rayleigh to explain the whispering gallery waves in St. Paul＇s Cathedral in London. Similar whispering gallery sound waves are now a popular tourist attraction at the Echo Wall of the Temple of Heaven in Beijing. Whispering gallery phenomena also exist for light waves in dielectric spheres, disks, or toroids where total internal reflection allows the light to circulate with little attenuation and interfere with itself to form optical resonances or modes. These ＂whisper- ing gallery modes＂ have found applications ranging from photonics, quantum physics, biosensing, to optical clocks [1,2].

关键词： Chaotic ray dynamics enables photonics broadband light

Response of small rodents to manipulations of vegetation height in agro-ecosystems

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Integrative Zoology 2008年第1期3卷 3-10页

作者： jens JACOB Federal Research Centre for Cultivated Plants-Julius Kuehn Institute Vertebrate ResearchMünsterGermany

Some small mammal populations require human interference to conserve rare or threatened species or to minimizeadverse effects in plant production. Without a thorough understanding about how small rodents behave in theirenvironment and consideration of how they react to management efforts, management will not be optimal. Socialbehavior, spatial and temporal activity patterns, predator avoidance and other behavioral responses can affect pestrodent management. Some of these behavioral patterns and their causes have been well studied. However, theirimpact on pest rodent management, especially for novel management approaches, is not always clear. Habitatmanipulation occurs necessarily through land use and intentionally to reduce shelter and food availability and toincrease predation pressure on rodents. Rodents often respond to decreased vegetation height with reducedmovements and increased risk sensitivity in their feeding behavior. This seems to result mainly from an elevatedperceived predation risk. Behavioral responses may lessen the efficacy of the management because the desiredeffects of predators might be mediated. It remains largely unknown to what extent such responses can compensateat the population level for the expected consequences of habitat manipulation and how population size and cropdamage are affected. It is advantageous to understand how target and non-target species react to habitatmanipulation to maximize the management effects by appropriate techniques, timing and spatial scale withoutcausing unwanted effects at the system level.

关键词： behavior crop protection pest rodent population dynamics vegetation height

Control and Nash Games with Mean Field Effect

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Chinese Annals of Mathematics,Series B 2013年第2期34卷 161-192页

作者： Alain BENSOUSSAN jens FREHSE International Center for Decision and Risk Analysis School of Management University of Texas-DallasFrance School of Business the Hong Kong Polytechnic University Graduate Department of Financial Engineering Ajou University Institute for Applied Mathematics University of Bonn

Mean field theory has raised a lot of interest in the recent years (see in particular the results of Lasry-Lions in 2006 and 2007,of Gueant-Lasry-Lions in 2011,of HuangCaines-Malham in 2007 and many others).There are a lot of *** general,the applications concern approximating an infinite number of players with common behavior by a representative *** agent has to solve a control problem perturbed by a field equation,representing in some way the behavior of the average infinite number of *** approach does not lead easily to the problems of Nash equilibrium for a finite number of players,perturbed by field equations,unless one considers averaging within different groups,which has not been done in the literature,and seems quite *** this paper,the authors approach similar problems with a different motivation which makes sense for control and also for differential *** the systems of nonlinear partial differential equations with mean field terms,which have not been addressed in the literature so far,are considered here.

关键词： Mean field Dynamic programming Nash games Equilibrium Calculus of variations

Research-A blockchainofknowledge?

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Blockchain(Research and Applications) 2020年第1期1卷 44-47页

作者： jens Ducree School of Physical Sciences Dublin City UniversityDublin 9Ireland

This perspective proposes that,by virtue of its sophisticated trust and consensus finding mechanisms,blockchain has the clear potential to substantially upgrade the processes and organization traditionally underpinning academic science and commercial technology development comprising funding,project delivery,generation of intellectual property,documentation and *** supporting this hypothesis,striking analogies between the concepts underlying blockchain technology with research are identified,and applied to the generation of verified knowledge in science and technology *** is then elaborated how a blockchain-enabled token economy can efficiently and transparently incentivize and coordinate an integrative and community-inclusive participatory approach to fuel crowdsourcing of collective intelligence for contributing ideas,work,infrastructure,funding,data,validation,management,assessment,governance,arbitration and exploitation of ***,credibility and direction of projects are optimized by demanding collateral“skin-in-the-game”from contributors based on blockchain-enabled staking,reputation systems and prediction *** way research progress emerges as a chain of community generated and independently vetted blocks of scientific knowledge;these new blocks are concatenated with the state-of-the-art according to transparent consensus mechanisms.

关键词： Blockchain for research Reputation systems Consensus Prediction markets Tokenization Blockchain-enabled staking Incentivization

Bistability theorem in a cancer model

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International Journal of Biomathematics 2018年第1期11卷 61-98页

作者： jens Christian Larsen Vanlcse Alle 50 2. mr. tv2720 VanlCse Copenhagen Denmark

In this paper, I continue the study of the mathematical models presented in [J. C. Larsen, Models of cancer growth, J. Appl. Math. Comput. 53（1-2）（2015） 613-645] and [J. C. Larsen, The bistability theorem in a model of metastatic cancer, to appear in Appl. Math.]. I shall prove the bistability theorem for the ODE model from [Larsen, 2015]. It is a mass action kinetic system in the variables C cancer, GF growth factor and GI growth inhibitor. This theorem says that for some values of the parameters, there exist two positive singular points c＊＋ = （C＊＋, GF＊., GI＊＋）, c＊2- = （C＊-, GF＊, GI＊-） of the vector field. Here C＊- 〈 C＊＋ and e. is stable and c＊＋ is unstable, see Sec. 2. There is also a discrete model in [Larsen, 2015], it is a linear map （T） on three-dimensional Euclidean vector space with variables （C, GF, GI）, where these variables have the same meaning as in the ODE model above. In [Larsen, 2015], I showed that one can sometimes find attine vector fields on three-dimensional Euclidean vector space whose time one map is T. I shall also show this in the present paper in a more general setting than in [Larsen, 2015]. This enables me to find an expression for the rate of change of cancer growth on the coordinate hyperplane C = 0 in Euclidean vector space. I also present an ODE model of cancer metastasis with variables C, CM, CF,GI, where C is primary cancer and CM is metastatic cancer and GF, GI are growth factors and growth inhibitors, respectively.

关键词： Immunology cancer chemotherapy immune therapy discrete dynamicalsystem Gompertz function.

Environmental analysis of innovative sustainable composites with potential use in aviation sector -A life cycle assessment review

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Science China(Technological Sciences) 2017年第9期60卷 1301-1317页

作者： BACHMANN jens HIDALGO Carme RICOUT Stephanie Deutsches Zentrum fiir Lufi- und Raumfahrt e. V. (German Aerospace Centre) Institute of Composite Structures and Adaptive Systems-Department of Multifunctional Materials Lilienthalplatz 7 38108 Braunsehweig Germany Leitat Technological Center C/Innovacio 2 08225 Terrassa Spain Airbus Group Innovations Fuels and Environment 12 rue Pasteur 92152 Suresnes France

The forecast of growing air transport in the upcoming decades faces the challenge of an increasing environmental *** industry is working on promising technologies to mitigate this environmental *** design is a strong lever to lower the fuel consumption and,consequently,with it the emissions of *** performance composites are a key technology to help achieve these aims thanks to their favourable combination of mechanical properties and low weight in primary ***,mainly synthetic materials such as petrol based carbon fibres and epoxy resins are used nowadays to produce composite in *** materials like bio-based fibres and resin systems offer potential environmental ***,they have not found their way into aviation,*** reasons are reduced mechanical properties and,especially for the use of natural fibres,their *** of these shortcomings are under *** the application of bio-based and recycled materials in certain areas of the aircraft could be possible in the *** examples for applications are furnishings and secondary *** motivation for this paper is to give an overview of potential environmental properties by using such eco-materials in *** cycle assessment(LCA) is a tool to calculate environmental impacts during all life stages of a *** main focus is laid on the bio-fibres flax and ramie,recycled carbon fibres and bio-based thermoset resin *** an overview of environmental aspects of existing composite materials used in aviation is ***,a lack of LCA results for the substitution of synthetic materials by bio-based/recycled composite materials in aviation applications has been ***,available information from other transport areas,such as automotive,has been *** detailed LCA data for eco-composite materials and technologies to improve their properties is import

关键词： aviation composite natural fibre recycled carbon fibre bio-resin cabin interior secondary structure,fife cycle assessment (LCA)

Semen analysis from an epidemiologic perspective

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Asian Journal of Andrology 2010年第1期12卷 91-94页

作者： jens Peter Ellekilde Bonde Department of Environmental and Occupational Medicine Copenhagen University Hospital Bispebjerg Bakke 23 2400Copenhagen NV Denmark

The fifth edition of the World Health Organization （WHO） manual for semen analysis includes for the first time reference values for human semen characteristics. This paper considers whether such values will help to resolve the intensely debated data indicating temporal and geographical shifts in sperm counts and hypotheses that anthropogenic activities that result in the release of chemicals into the environment are detrimental to male reproductive health. The reasons that these reference values will not fulfil these purposes are also explained. Although established reference values for semen characteristics are of limited value in analytical epidemiologic research, the WHO guidelines are of utmost importance for supporting the development of appropriate research protocols. Moreover, in spite of its limitations, semen analysis is still a useful research tool in epidemiological research, and no superior alternatives are on the horizon.

关键词： decline epidemiology reference values research semen analysis sperm counts

A finite element analysis(FEA)approach to simulate the coefficient of friction of a brake system starting from material friction characterization

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Friction 2021年第1期9卷 191-200页

作者： Gabriele RIVA Francesco VARRIALE jens WAHLSTRÖM brembo S.p.A. Stezzano(BG)Stezzano(BG)24040Italy KTH Royal Institute of Technology Stockholm 11428Sweden Department of Mechanical Engineering Lund UniversityLund 22100Sweden

The coefficient of friction(COF)is one of the most important parameters to evaluate the performance of a brake *** design proper brake systems,it is important to know the COF when estimating the brake force and resulting *** is challenging to simulate the COF since friction in disc brakes is a complex phenomenon that depends on several parameters such as sliding velocity,contact pressure,materials,and temperatures,*** is a lack of studies found in the literature focusing on simulation of the COF for a full brake system based on tribometer material *** aim of this work is therefore to investigate the possibility to use a finite element analysis(FEA)approach combined with a COF pv-map to compute the global COF of a disc brake *** local COF is determined from a pv-map for each local sliding velocity and contact pressure determined by the *** the local COF,the braking force of the entire brake system and the global COF can be *** obtained by the simulation are compared with dyno bench test of the same brake system to investigate the validity of the simulation *** show that the simulation is perfectly in line with the experimental measurements in terms of in-stop COF development,but slightly higher with a positive offset for every braking.

关键词： disc brakes friction coefficient simulation brake performance pin-on-disc

Model Experiments on Melting of Alloys with Low Melting Temperature in a Medium with High Melting Temperature

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Journal of Iron and Steel Research International 1999年第2期6卷 1-9页

作者： Becker jens-Ulrik Oeters Franz Thyssen-Krupp Stahl GmbH Technical University Berlin

Experiments of alloy melting were carried out in water/HCl H 2O eutectic model system. The eutectic has a solid liquid equilibrium temperature of -74 ℃. 5 cm diameter spheres of the eutectic in which three thermocouples in the core, on the edge and in the middle between them had been positioned were cooled to -196 ℃ in liquid nitrogen. After cooling the spheres were immersed into water of 10 ℃, and the changes of temperatures with time in the three thermocouples were measured. In some experiments the temperature on the outer side of the spheres where an ice shell grew up was also measured. In these experiments, the growing rate of the shell was additionally determined. The results for the first minute of the melting process, where the system can be considered as one dimensional, were described by an exact solution of Fouriers equation. The density of liquid ferromanganese at 1 500 ℃ was measured.

关键词： alloy melting model experiment

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