107 research outputs found
The system individualized principles of management of technologies of field husbandry.
The system and organized, local individualized agrotechnologies provide on the land ground divided into priority zones, the simultaneous parallel and interconnected performance of a complex of technological operations on production of crop production: operations on preparation of seeds of an agriculture, cultivation of seedling, laying of seedling to the soil, to cultivation of an agriculture, stimulation of her development. Interaction between the carried-out processes is carried out in real time with a possibility of necessary corrections of processes during their performance. A considerable part of technological operations realize without rendering negative impacts on an agriculture, the soil and the environment, with small expenses of energy
Principles of management of agrotechnological systems.
Modern approaches to the solution of problems of increase in the outputs and quality, reduction of cost of agricultural production, negative impacts of agropro-technologies on the environment provide consideration of transformation of energy in agroprocesses as a part of uniform agrotechnological systems. Creation of a control system of devices of different function and application on the basis of modular model doesn\u27t demand development of difficult algorithms and schemes of management. Application of modular models, use in them standard mathematical dependences for forecasting of changes of characteristics of processes and management significantly simplifies technical realization of elements of a technogenic part of agrotechnological centers, creates possibilities of unification of circuit and software solutions for various control units agroprocesses, reduces expenses of time and material manpower at a stage of their development and deployment
Multipoint Vernier VISAR Interferometer System for Measuring Mass Velocity in Shock Wave Experiments
AbstractThe results of development of a laser interferometer designed to measure the mass velocity of condensed substances in shock wave experiments in the field of high energy density physics are presented. The developed laser system allows measurements of the velocity of free surfaces of samples in shockwave experiments with accuracy no worse than 10 m/s for the entire range of velocities attained experimentally. The time resolution of measurements is limited by the response speed of the used PMTs and amounts to 2.5 ns
Modelling laser-atom interactions in the strong field regime
We consider the ionisation of atomic hydrogen by a strong infrared field. We
extend and study in more depth an existing semi-analytical model. Starting from
the time-dependent Schroedinger equation in momentum space and in the velocity
gauge we substitute the kernel of the non-local Coulomb potential by a sum of N
separable potentials, each of them supporting one hydrogen bound state. This
leads to a set of N coupled one-dimensional linear Volterra integral equations
to solve. We analyze the gauge problem for the model, the different ways of
generating the separable potentials and establish a clear link with the strong
field approximation which turns out to be a limiting case of the present model.
We calculate electron energy spectra as well as the time evolution of electron
wave packets in momentum space. We compare and discuss the results obtained
with the model and with the strong field approximation and examine in this
context, the role of excited states.Comment: 11 pages, 5 figure
Measurement of prompt hadron production ratios in collisions at 0.9 and 7 TeV
The charged-particle production ratios , , ,
, and are measured with the LHCb detector using of collisions delivered by the LHC at TeV and
at TeV. The measurements are performed as a
function of transverse momentum and pseudorapidity . The
production ratios are compared to the predictions of several Monte Carlo
generator settings, none of which are able to describe adequately all
observables. The ratio is also considered as a function of rapidity
loss, , and is used to constrain models of
baryon transport.Comment: Incorrect entries in Table 2 corrected. No consequences for rest of
pape
Measurement of CP asymmetries and branching fraction ratios of Bâ decays to two charm mesons
The asymmetries of seven decays to two charm mesons are measured using data corresponding to an integrated luminosity of of proton-proton collisions collected by the LHCb experiment. Decays involving a or meson are analysed by reconstructing only the or decay products. This paper presents the first measurement of and , and the most precise measurement of the other five asymmetries. There is no evidence of violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.The CP asymmetries of seven B decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb of proton-proton collisions collected by the LHCb experiment. Decays involving a D or meson are analysed by reconstructing only the D or decay products. This paper presents the first measurement of (BâD) and (BâD), and the most precise measurement of the other five CP asymmetries. There is no evidence of CP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.[graphic not available: see fulltext]The asymmetries of seven decays to two charm mesons are measured using data corresponding to an integrated luminosity of of proton-proton collisions collected by the LHCb experiment. Decays involving a or meson are analysed by reconstructing only the or decay products. This paper presents the first measurement of and , and the most precise measurement of the other five asymmetries. There is no evidence of violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured
Helium identification with LHCb
The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at â(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei
Momentum scale calibration of the LHCb spectrometer
For accurate determination of particle masses accurate knowledge of the momentum scale of the detectors is crucial. The procedure used to calibrate the momentum scale of the LHCb spectrometer is described and illustrated using the performance obtained with an integrated luminosity of 1.6 fb-1 collected during 2016 in pp running. The procedure uses large samples of J/Ï â ÎŒ + ÎŒ - and B+ â J/Ï K + decays and leads to a relative accuracy of 3 Ă 10-4 on the momentum scale
Curvature-bias corrections using a pseudomass method
Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy â(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using ZâÎŒ + ÎŒ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the ZâÎŒ + ÎŒ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass
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