1,180 research outputs found

    The Hyperfine Coupling Radical Pair Mechanism of Biological Effects on Weak Magnetic Fields

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    More recent concerns have been raised about the biological effects of all different weak magnetic fields (MFs) with the development of electric device era and information era. The biological effects due to weak MFs just like a hypomagnetic field (HMF) or near-null magnetic field is a very important subject for aerospace traveling and space station living. A large number of studies on the biological effects of other weak MFs have been carried out. The biological effects of different weak MFs can be negative or positive. Many mechanisms to explain the bioeffects of weak MFs have been given. Are there possible common mechanisms of the different biological effects in different weak MFs ? It’s unbelievable and sound impossible at first sight that different bioeffects of different weak MFs have common mechanisms. But possible common mechanisms can exist. In this study, the author proposes the relations between the singlet yield of the radical pair and the weak MFs are the possible common mechanisms. Giving one possible common mechanism of bioeffects of all different weak MFs including impulsed ones is the first to the author’s known. Here, the weak MFs are ones that cannot produce thermal bioeffects not only limited below 1mT

    The radical pair mechanism of biological effects on hypomagnetic fields and one method to verify it

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    The biological effects due to a hypomagnetic field (HMF) is a very important subject not only for aerospace traveling and space station living but also for some magnetic shielding conditions on the ground just like the underground bunkers and etc. However, to my knowledge, the mechanisms which can be related to the biological effects of a HMF remain unclear. In this study, I firstly summary one radical pair mechanism of biological effects on a HMF based on present researches, and then propose how to prove the radical pair mechanism’s truth in biological effects on a HMF through experiments. In the way of how to prove the radical pair mechanism’s truth I give the relation between the singlet yield of the radical pair and the angle describing the orientation of a HMF to the basis of the hyperfine tensor related to the electron spin and the nuclei spin is the possible one radical pair mechanism on one hand, and give the crucial method which is through that angle changed causes the biological effects in vivo or vitro to prove or disprove the mechanism on the other hand, because the biological effects of a HMF can be related with that angle, which is very easy to be controlled in experiments

    One Mobile Phone Model of Chinese Medical Qigong Therapies

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    Background: Qigong is one characteristic therapy of traditional Chinese medicine(TCM), and it has benefited more and more. However, to our best knowledge, the physical model of Qigong therapies remains unknown. Method: Based on the progress of modern science, one physical model of Qiong therapy-mobile phone model is presented. Discussions: The main points of the model are: one normal healthy person is just like one mobile phone which is communicating well in the net, the internal Qi of the person is just like the standing electromagnetic waves inside of the mobile phone, and the external Qi is just like the travelling electromagnetic waves outside of it; the best Qigong state of one healthy person is considered just like one continuing optimal mobile phone, with development one generation by one generation and with strong signal communicating well in net, not like one fixed to one generation. The reason of one person is sick is the electromagnetic waves inside of the person deviates from standing waves or the electromagnetic waves outside deviates from travelling waves. It is the first step to correct the deviation for one patient to cultivate Qigong and finally to get the optimal state of integrating the Three Adjustments into one. The rationality of the mobile phone model and the essence of Qi in the model are discussed

    Backaction of a charge detector on a double quantum dot

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    We develop a master equation approach to study the backaction of quantum point contact (QPC) on a double quantum dot (DQD) at zero bias voltage. We reveal why electrons can pass through the zero-bias DQD only when the bias voltage across the QPC exceeds a threshold value determined by the eigenstate energy difference of the DQD. This derived excitation condition agrees well with experiments on QPC-induced inelastic electron tunneling through a DQD [S. Gustavsson et al., Phys. Rev. Lett. 99, 206804(2007)]. Moreover, we propose a new scheme to generate a pure spin current by the QPC in the absence of a charge current.Comment: 6 pages, 4 figure

    Cooling a nanomechanical resonator by a triple quantum dot

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    We propose an approach for achieving ground-state cooling of a nanomechanical resonator (NAMR) capacitively coupled to a triple quantum dot (TQD). This TQD is an electronic analog of a three-level atom in Λ\Lambda configuration which allows an electron to enter it via lower-energy states and to exit only from a higher-energy state. By tuning the degeneracy of the two lower-energy states in the TQD, an electron can be trapped in a dark state caused by destructive quantum interference between the two tunneling pathways to the higher-energy state. Therefore, ground-state cooling of an NAMR can be achieved when electrons absorb readily and repeatedly energy quanta from the NAMR for excitations.Comment: 6 pages, 3 figure
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