1,052 research outputs found
Modeling of Injection Parameters for Diesel Engine Injector Nozzles with the Additional Precision Guiding Interface
AbstractPerfection of output parameters of diesel engines is considered as a result of the rail-pressure increase and modernization of nozzle tribosystems represented at high (up to 300 MPa) values of the fuel pressure. The nozzle with the modified design and additional (bottom) precision guiding interface is used and hydrodynamic parameters of injection are analyzed. The computational fluid-dynamic (CFD) modeling for estimation of hydrodynamic parameters of the fuel flow and force distribution in the βneedle β nozzle bodyβ system is used. The results of the injection modeling and contact parameters for the modified design of nozzle precision interfaces are established and discussed. The ways of increasing the stability of needle position in the nozzle body with perfection of parameters of fuel injection are presented
Combinatorics and formal geometry of the master equation
We give a general treatment of the master equation in homotopy algebras and
describe the operads and formal differential geometric objects governing the
corresponding algebraic structures. We show that the notion of Maurer-Cartan
twisting is encoded in certain automorphisms of these universal objects
Electrical control of optical orientation of neutral and negatively charged excitons in n-type semiconductor quantum well
We report a giant electric field induced increase of spin orientation of
excitons in n-type GaAs/AlGaAs quantum well. It correlates strongly with the
formation of negatively charged excitons (trions) in the photoluminescence
spectra. Under resonant excitation of neutral heavy-hole excitons, the
polarization of excitons and trions increases dramatically with electrical
injection of electrons within the narrow exciton-trion bias transition in the
PL spectra, implying a polarization sensitivity of 200 % per Volt. This effect
results from a very efficient trapping of neutral excitons by the quantum well
interfacial fluctuations (so-called "natural" quantum dots) containing resident
electrons.Comment: 18 pages, 4 figure
Coherent lidars based on intracavity heterodyning of echo signals
The development and technical realization of the method of laser sounding of the atmosphere based on the effects of mixing of reference and external fields of scattering inside a laser cavity are presented. An approximate theory of the method was developed on the basis of the investigations using the model of a three-mirror laser. The nonlinear effect of a wideband laser on frequency-dependent external influences of the atmosphere was investigated. The field measurements of gaseous composition of the atmosphere were performed on the basis of a given method of coherent reception using a tunable CO2 laser
Current issues of conformity of cements
ΠΠ°Π½Π½Π°Ρ ΡΡΠ°ΡΡΡ ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° Π²ΠΎΠΏΡΠΎΡΠ°ΠΌ ΠΏΠ΅ΡΠ΅Ρ
ΠΎΠ΄Π° ΡΠ΅ΠΌΠ΅Π½ΡΠ° ΠΈΠ· Π΄ΠΎΠ±ΡΠΎΠ²ΠΎΠ»ΡΠ½ΠΎΠΉ ΠΎΠ±Π»Π°ΡΡΠΈ ΡΠ΅Π³ΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π² ΠΎΠ±Π»Π°ΡΡΡ ΠΎΠ±ΡΠ·Π°ΡΠ΅Π»ΡΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π΅Π½ΠΈΡ ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΠΈΡ. ΠΠ΄Π½Π°ΠΊΠΎ ΠΌΠ½ΠΎΠ³ΠΈΠ΅ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡΠ΅Π»ΠΈ ΠΎΠΊΠ°Π·Π°Π»ΠΈΡΡ Π½Π΅ Π³ΠΎΡΠΎΠ²Ρ ΠΊ ΡΠ°ΠΊΠΈΠΌ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡΠΌ. ΠΡΠ½ΠΎΠ²Π½ΠΎΠΉ ΠΏΡΠΈΡΠΈΠ½ΠΎΠΉ ΡΡΠΎΠ³ΠΎ ΡΠ²ΠΈΠ»ΠΎΡΡ Π½Π΅Π½Π°Π΄Π»Π΅ΠΆΠ°ΡΠ΅Π΅ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΉ Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΠ°ΡΠΈΠΈ, ΡΡΠ΅Π±ΡΠ΅ΠΌΠΎΠΉ Π² ΠΎΠ±ΡΠ·Π°ΡΠ΅Π»ΡΠ½ΠΎΠΌ ΠΏΠΎΡΡΠ΄ΠΊΠ΅ Π΄Π»Ρ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π΅Π½ΠΈΡ ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΠΈΡThis article focuses on the transition of the cement from the voluntary sector management in the area of mandatory confirmation of compliance. However, many producers were not ready to such changes. The main reason for this was inadequate maintenance of technical documentation required for obligatory confirmation of complianc
Quantum Oscillations of Elastic Moduli and Softening of Phonon Modes in Metals
In this paper we present a theoretical analysis of the effect of
magnetostriction on quantum oscillations of elastic constants in metals under
strong magnetic fields.
It is shown that at low temperatures a significant softening of some acoustic
modes could occur near peaks of quantum oscillations of the electron density of
states (DOS) at the Fermi surface (FS). This effect is caused by a magnetic
instability of a special kind, and it can give rise to a lattice instability.
We also show that the most favorable conditions for this instability to be
revealed occur in metals whose Fermi surfaces include nearly cylindrical
segments.Comment: 5 pages, 1 figur
ΠΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠΈ Π³ΠΈΠ΄ΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ ΡΠΈΡΡΠ΅ΠΌΡ Β«ΠΈΠ³Π»Π° ΡΠΎΠΏΠ»ΠΈΠ²ΠΎΒ» ΡΠΈΠ»ΠΈΠ½Π΄ΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΡΠ΅ΡΠΈΠ·ΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΡΡΠΈΠ±ΠΎΡΠΎΠΏΡΡΠΆΠ΅Π½ΠΈΡ ΡΠ°ΡΠΏΡΠ»ΠΈΡΠ΅Π»Ρ ΡΠΎΠΏΠ»ΠΈΠ²Π½ΠΎΠΉ ΡΠΎΡΡΡΠ½ΠΊΠΈ Π΄ΠΈΠ·Π΅Π»Ρ
The paper considers some operational peculiar features and basic equations of hydrodynamics with reference to movement of "needle fuel" system in precision cylindrical "needle case" triboconjugation of DL-series sprayer of diesel engine fuel-injection nozzle. The paper presents methodology that makes it possible to evaluate relations between mass and geometrical parameters of elements of cylindrical triboconjugation and fuel specifications in the process of needle fit in the seat of sprayer bodyΒ Π Π°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡΡΡ Π½Π΅ΠΊΠΎΡΠΎΡΡΠ΅ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠΈ ΡΡΠ½ΠΊΡΠΈΠΎΠ½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΠΎΡΠ½ΠΎΠ²Π½ΡΠ΅ ΡΡΠ°Π²Π½Π΅Π½ΠΈΡ Π³ΠΈΠ΄ΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ ΠΏΡΠΈΠΌΠ΅Π½ΠΈΡΠ΅Π»ΡΠ½ΠΎ ΠΊ Π΄Π²ΠΈΠΆΠ΅Π½ΠΈΡ ΡΠΈΡΡΠ΅ΠΌΡ Β«ΠΈΠ³Π»Π° ΡΠΎΠΏΠ»ΠΈΠ²ΠΎΒ» Π² ΠΏΡΠ΅ΡΠΈΠ·ΠΈΠΎΠ½Π½ΠΎΠΌ ΡΠΈΠ»ΠΈΠ½Π΄ΡΠΈΡΠ΅ΡΠΊΠΎΠΌ ΡΡΠΈΠ±ΠΎΡΠΎΠΏΡΡΠΆΠ΅Π½ΠΈΠΈ Β«ΠΈΠ³Π»Π° ΠΊΠΎΡΠΏΡΡΒ» ΡΠ°ΡΠΏΡΠ»ΠΈΡΠ΅Π»Ρ ΡΠ΅ΡΠΈΠΈ DL ΡΠΎΠΏΠ»ΠΈΠ²Π½ΠΎΠΉ ΡΠΎΡΡΡΠ½ΠΊΠΈ Π΄ΠΈΠ·Π΅Π»Ρ. ΠΡΠΈΠ²Π΅Π΄Π΅Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ°, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡΠ°Ρ ΠΎΡΠ΅Π½ΠΈΡΡ ΡΠ²ΡΠ·ΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΠΌΠ°ΡΡΠΎΠ²ΡΠΌΠΈ ΠΈ Π³Π΅ΠΎΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠ°ΠΌΠΈ ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ² ΡΠΈΠ»ΠΈΠ½Π΄ΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΡΠΈΠ±ΠΎΡΠΎΠΏΡΡΠΆΠ΅Π½ΠΈΡ ΠΈ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠ°ΠΌΠΈ ΡΠΎΠΏΠ»ΠΈΠ²Π° Π² ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΠΏΠΎΡΠ°Π΄ΠΊΠΈ ΠΈΠ³Π»Ρ Π½Π° ΡΠ΅Π΄Π»ΠΎ ΠΊΠΎΡΠΏΡΡΠ° ΡΠ°ΡΠΏΡΠ»ΠΈΡΠ΅Π»Ρ.Π Π²Π΅ΡΡΡΠΊΠ΅ ΡΡΠ°ΡΡΠΈ ΠΏΡΠΎΠΏΡΡΠ΅Π½Π° ΡΡΡΠ°Π½ΠΈΡ
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