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The determination of the neutrino rest mass plays an important role at the intersections of cosmology, particle physics and
astroparticle physics. This topic is currently being addressed by two complementary approaches in laboratory experiments.
Neutrinoless double beta decay experiments probe whether neutrinos are Majorana particles and determine an effective neutrino
mass value. Single beta decay experiments such as KATRIN and MARE investigate the spectral shape of β-decay electrons close
to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Owing to neutrino
flavour mixing, the neutrino mass parameter appears as an average of all neutrino mass eigenstates contributing to the electron
neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning.
Applying an ultra-luminous molecular windowless gaseous tritium source and an integrating high-resolution spectrometer of
MAC-E filter type, it allows β-spectroscopy close to the T
2 end-point with unprecedented precision and will reach a sensitivity of 200 meV/c
2 (90% C.L.) on the neutrino rest mass. 相似文献
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MARÍA EVANGELINA ALVAREZ SILVIA DI MARCO KATRIN ERDLENBRUCH MABEL TIDBALL 《Natural Resource Modeling》2016,29(3):353-373
In this paper, we study the optimal solutions of a model of natural resource management which allows for both impulse and continuous harvesting policies. This type of model is known in the literature as mixed optimal control problem. In the resource management context, each type of control represents a different harvesting technology, which has a different cost. In particular, we want to know when the following conjecture made by Clark is an optimal solution to this mixed optimal control problem: if the harvesting capacity is unlimited, it is optimal to jump immediately to the steady state of the continuous time problem and then to stay there. We show that under a particular relationship between the continuous and the impulse profit function, the conjecture made by Clark is true. In other cases, however, it is either better to use only continuous control variables or to jump to resource levels which are smaller than the steady state and then let the resource grow back to the steady state. These results emphasize the importance of the cost functions in the modeling of natural resource management. 相似文献
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Operator decomposable probabilities on vector spaces – generalizing (semi-)stable and self-decomposable laws – are well known. Here we are concerned with multiple decomposability on locally compact groups. In fact, as it turned out that contraction properties play an essential role, throughout we concentrate on contractible locally compact groups. 相似文献
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Impulsive control of a Lotka-Volterra system 总被引:4,自引:0,他引:4
This paper investigates control problems of a Lotka-Volterrapopulation growth model. We assume that our only means of controllingthe population dynamics is via impulses in the N1 population,i.e. adding or removing some members. With this impulsive control,we establish criteria for keeping all the species from goingextinct by stabilizing some positive point, which may not bethe equilibrium point of the system. Several examples are alsoworked out. 相似文献
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