47 research outputs found

    ВЛИЯНИЕ СИСТЕМ УДОБРЕНИЯ НА ПРОДУКТИВНОСТЬ СЕВООБОРОТА И АГРОХИМИЧЕСКИЕ ПОКАЗАТЕЛИ ДЕРНОВО-ПОДЗОЛИСТОЙ СУПЕСЧАНОЙ ПОЧВЫ

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    The influence of by products ploughing and mineral fertilizer doses on the crop rotation productivity and agrochemi-cal indicators of sod-podzolic sandy loam soil is studied. It’s established that autumn application of a compensatory dose of nitrogen to the straw didn’t ensure the increased productivity of crop rotation. It’s shown that application of correct doses of phosphorus and potassium fertilizers taking into account the phosphorus and potassium from a straw predecessor didn’t bring about the reduction of the productivity of crop rotation in comparison with the application of full doses of fertilizers and allowed saving P60 and K360.Изучено влияние запашки побочной продукции и доз минеральных удобрений на продуктивность севооборота и агрохимические показатели дерново-подзолистой супесчаной почвы. Установлено, что осеннее внесение компенсирующей дозы азота по соломе не обеспечило существенного увеличения продуктивности севооборота. Показано, что внесение скорректированных доз фосфорных и калийных удобрений с учетом фосфора и калия, высвобождающихся из соломы предшественника, не привело к снижению продуктивности севооборота по сравнению с применением полных доз удобрений и позволило сохранить Р60 и K360

    The solid-state photo-CIDNP effect

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    The solid-state photo-CIDNP effect is the occurrence of a non-Boltzmann nuclear spin polarization in rigid samples upon illumination. For solid-state NMR, which can detect this enhanced nuclear polarization as a strong modification of signal intensity, the effect allows for new classes of experiments. Currently, the photo- and spin-chemical machinery of various RCs is studied by photo-CIDNP MAS NMR in detail. Until now, the effect has only been observed at high magnetic fields with 13C and 15N MAS NMR and in natural photosynthetic RC preparations in which blocking of the acceptor leads to cyclic electron transfer. In terms of irreversible thermodynamics, the high-order spin structure of the initial radical pair can be considered as a transient order phenomenon emerging under non-equilibrium conditions and as a first manifestation of order in the photosynthetic process. The solid-state photo-CIDNP effect appears to be an intrinsic property of natural RCs. The conditions of its occurrence seem to be conserved in evolution. The effect may be based on the same fundamental principles as the highly optimized electron transfer. Hence, the effect may allow for guiding artificial photosynthesis

    Transmembrane potential induced on the internal organelle by a time-varying magnetic field: a model study

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    <p>Abstract</p> <p>Background</p> <p>When a cell is exposed to a time-varying magnetic field, this leads to an induced voltage on the cytoplasmic membrane, as well as on the membranes of the internal organelles, such as mitochondria. These potential changes in the organelles could have a significant impact on their functionality. However, a quantitative analysis on the magnetically-induced membrane potential on the internal organelles has not been performed.</p> <p>Methods</p> <p>Using a two-shell model, we provided the first analytical solution for the transmembrane potential in the organelle membrane induced by a time-varying magnetic field. We then analyzed factors that impact on the polarization of the organelle, including the frequency of the magnetic field, the presence of the outer cytoplasmic membrane, and electrical and geometrical parameters of the cytoplasmic membrane and the organelle membrane.</p> <p>Results</p> <p>The amount of polarization in the organelle was less than its counterpart in the cytoplasmic membrane. This was largely due to the presence of the cell membrane, which "shielded" the internal organelle from excessive polarization by the field. Organelle polarization was largely dependent on the frequency of the magnetic field, and its polarization was not significant under the low frequency band used for transcranial magnetic stimulation (TMS). Both the properties of the cytoplasmic and the organelle membranes affect the polarization of the internal organelle in a frequency-dependent manner.</p> <p>Conclusions</p> <p>The work provided a theoretical framework and insights into factors affecting mitochondrial function under time-varying magnetic stimulation, and provided evidence that TMS does not affect normal mitochondrial functionality by altering its membrane potential.</p
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