198 research outputs found
Nonisospectral integrable nonlinear equations with external potentials and their GBDT solutions
Auxiliary systems for matrix nonisospectral equations, including coupled NLS
with external potential and KdV with variable coefficients, were introduced.
Explicit solutions of nonisospectral equations were constructed using the GBDT
version of the B\"acklund-Darboux transformation
Maxwell-Bloch equation and Correlation function for penetrable Bose gas
We consider the quantum nonlinear Schr\"odinger equation in one space and one
time dimension. We are interested in the non-free-fermionic case. We consider
static temperature-dependent correlation functions. The determinant
representation for correlation functions simplifies in the small mass limit of
the Bose particle. In this limit we describe the correlation functions by the
vacuum expectation value of a boson-valued solution for Maxwell-Bloch
differential equation. We evaluate long-distance asymptotics of correlation
functions in the small mass limit.Comment: LaTEX file, 20 pages, to appear J. Phys. A (1997
INVERSE SCATTERING TRANSFORM ANALYSIS OF STOKES-ANTI-STOKES STIMULATED RAMAN SCATTERING
Zakharov-Shabat--Ablowitz-Kaup-Newel-Segur representation for
Stokes-anti-Stokes stimulated Raman scattering is proposed. Periodical waves,
solitons and self-similarity solutions are derived. Transient and bright
threshold solitons are discussed.Comment: 16 pages, LaTeX, no figure
Investigation of oxidation process of mechanically activated ultrafine iron powders
The oxidation of mechanically activated ultrafine iron powders was studied using X-ray powder diffraction and thermogravimetric analyzes. The powders with average particles size of 100 nm were made by the electric explosion of wire, and were subjected to mechanical activation in planetary ball mill for 15 and 40 minutes. It was shown that a certain amount of FeO phase is formed during mechanical activation of ultrafine iron powders. According to thermogravimetric analysis, the oxidation process of non-milled ultrafine iron powders is a complex process and occurs in three stages. The preliminary mechanical activation of powders considerably changes the nature of the iron powders oxidation, leads to increasing in the temperature of oxidation onset and shifts the reaction to higher temperatures. For the milled powders, the oxidation is more simple process and occurs in a single step
Explicit solutions of the four-wave mixing model
The dynamical degenerate four-wave mixing is studied analytically in detail.
By removing the unessential freedom, we first characterize this system by a
lower-dimensional closed subsystem of a deformed Maxwell-Bloch type, involving
only three physical variables: the intensity pattern, the dynamical grating
amplitude, the relative net gain. We then classify by the Painleve' test all
the cases when singlevalued solutions may exist, according to the two essential
parameters of the system: the real relaxation time tau, the complex response
constant gamma. In addition to the stationary case, the only two integrable
cases occur for a purely nonlocal response (Real(gamma)=0), these are the
complex unpumped Maxwell-Bloch system and another one, which is explicitly
integrated with elliptic functions. For a generic response (Re(gamma) not=0),
we display strong similarities with the cubic complex Ginzburg-Landau equation.Comment: 16 pages, J Phys A Fast track communication, to appear 200
Medical therapy in the immediate and late postoperative periods after a partial transurethral resection of the prostate in the middle-aged men
In paper analysis of the results of alpha - blockers monotherapy application and combined therapy of alpha - blockers and muscarinic receptor antagonists in the immediate and late postoperative periods after partial transurethral resection of prostate, performed due to benign prostatic hyperplasia in the middle aged men (up to 55 y.o.) is presented. Itβs revealed that in the middle aged patients who underwent partial TURP the short and long-term postoperative use of a combination of alpha - blockers and muscarinic receptor antagonists to relieve effects of dysuria and irritative symptoms and to preserve the copulative (ejaculatory) function is more preferable than monotherapy with alpha -1 - adrenergic blockers. No significant differences in the effectiveness of therapy with superselective (tamsulosin) and selective (doxazosin) alpha -1 - adrenergic blockers are observed, although special for each drug side β effects were detected. The combination technique of partial TURP for BPH and medical treatment held in the postoperative period preserves antegrade ejaculation in the majority (89,5%) of the middle aged patients, thus minimizing the influence on their quality life after surgery.Π ΡΠ°Π±ΠΎΡΠ΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ Π°Π½Π°Π»ΠΈΠ· ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΌΠΎΠ½ΠΎΡΠ΅ΡΠ°ΠΏΠΈΠΈ Π°Π»ΡΡΠ° - Π°Π΄ΡΠ΅Π½ΠΎΠ±Π»ΠΎΠΊΠ°ΡΠΎΡΠ°ΠΌΠΈ ΠΈ ΠΊΠΎΠΌΠ±ΠΈΠ½ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΡΠ΅ΡΠ°ΠΏΠΈΠΈ Π°Π»ΡΡΠ° - Π°Π΄ΡΠ΅Π½ΠΎΠ±Π»ΠΎΠΊΠ°ΡΠΎΡΠ°ΠΌΠΈ ΠΈ Π°Π½ΡΠ°Π³ΠΎΠ½ΠΈΡΡΠ°ΠΌΠΈ ΠΌΡΡΠΊΠ°ΡΠΈΠ½ΠΎΠ²ΡΡ
ΡΠ΅ΡΠ΅ΠΏΡΠΎΡΠΎΠ² Ρ ΠΌΡΠΆΡΠΈΠ½ ΡΡΠ΅Π΄Π½Π΅Π³ΠΎ Π²ΠΎΠ·ΡΠ°ΡΡΠ° (Π΄ΠΎ 55Π»Π΅Ρ) Π² Π±Π»ΠΈΠΆΠ°ΠΉΡΠ΅ΠΌ ΠΈ ΠΎΡΠ΄Π°Π»Π΅Π½Π½ΠΎΠΌ ΠΏΠΎΡΠ»Π΅ΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΌ ΠΏΠ΅ΡΠΈΠΎΠ΄Π°Ρ
ΠΏΠΎΡΠ»Π΅ ΠΏΠ°ΡΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ ΡΡΠ°Π½ΡΡΡΠ΅ΡΡΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ΅Π·Π΅ΠΊΡΠΈΠΈ ΠΏΡΠΎΡΡΠ°ΡΡ, Π²ΡΠΏΠΎΠ»Π½Π΅Π½Π½ΠΎΠΉ ΠΏΠΎ ΠΏΠΎΠ²ΠΎΠ΄Ρ Π΄ΠΎΠ±ΡΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠΉ Π³ΠΈΠΏΠ΅ΡΠΏΠ»Π°Π·ΠΈΠΈ ΠΏΡΠ΅Π΄ΡΡΠ°ΡΠ΅Π»ΡΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ. Π ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΈ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Ρ ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠ² ΡΡΠ΅Π΄Π½Π΅Π³ΠΎ Π²ΠΎΠ·ΡΠ°ΡΡΠ°, ΠΏΠΎΠ΄Π²Π΅ΡΠ³ΡΠΈΡ
ΡΡ ΠΏΠ°ΡΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ Π’Π£Π ΠΏΡΠΎΡΡΠ°ΡΡ, Π² Π±Π»ΠΈΠΆΠ°ΠΉΡΠ΅ΠΌ ΠΈ ΠΎΡΠ΄Π°Π»Π΅Π½Π½ΠΎΠΌ ΠΏΠΎΡΠ»Π΅ΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΌ ΠΏΠ΅ΡΠΈΠΎΠ΄Π°Ρ
ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ ΠΊΠΎΠΌΠ±ΠΈΠ½Π°ΡΠΈΠΈ Π°Π»ΡΡΠ° - Π°Π΄ΡΠ΅Π½ΠΎΠ±Π»ΠΎΠΊΠ°ΡΠΎΡΠΎΠ² ΠΈ Π - Ρ
ΠΎΠ»ΠΈΠ½ΠΎΠ»ΠΈΡΠΈΠΊΠΎΠ² Ρ ΡΠ΅Π»ΡΡ ΠΊΡΠΏΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»Π΅Π½ΠΈΠΉ Π΄ΠΈΠ·ΡΡΠΈΠΈ ΠΈ ΠΈΡΡΠΈΡΠ°ΡΠΈΠ²Π½ΠΎΠΉ ΡΠΈΠΌΠΏΡΠΎΠΌΠ°ΡΠΈΠΊΠΈ ΠΈ ΡΠΎΡ
ΡΠ°Π½Π΅Π½ΠΈΡ ΠΊΠΎΠΏΡΠ»ΡΡΠΈΠ²Π½ΠΎΠΉ (Π·ΡΠΊΡΠ»ΡΡΠΎΡΠ½ΠΎΠΉ) ΡΡΠ½ΠΊΡΠΈΠΈ ΡΠ²Π»ΡΠ΅ΡΡΡ Π±ΠΎΠ»Π΅Π΅ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΡΠΌ, ΡΠ΅ΠΌ ΠΌΠΎΠ½ΠΎΡΠ΅ΡΠ°ΠΏΠΈΡ Π°Π»ΡΡΠ° -1 - Π°Π΄ΡΠ΅Π½Π±Π»ΠΎΠΊΠ°ΡΠΎΡΠ°ΠΌΠΈ. ΠΠΎΡΡΠΎΠ²Π΅ΡΠ½ΡΡ
ΡΠ°Π·Π»ΠΈΡΠΈΠΉ Π² ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΡΠ΅ΡΠ°ΠΏΠΈΠΈ ΠΏΡΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠΈ ΡΠ²Π΅ΡΡ
ΡΠ΅Π»Π΅ΠΊΡΠΈΠ²Π½ΡΡ
(ΡΠ°ΠΌΡΡΠ»ΠΎΠ·ΠΈΠ½) ΠΈ ΡΠ΅Π»Π΅ΠΊΡΠΈΠ²Π½ΡΡ
(Π΄ΠΎΠΊΡΠ°Π·ΠΎΠ·ΠΈΠ½) Π°Π»ΡΡΠ° - 1 - Π°Π΄ΡΠ΅Π½ΠΎΠ±Π»ΠΎΠΊΠ°ΡΠΎΡΠΎΠ² Π½Π΅ ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΎ, Ρ
ΠΎΡΡ Π²ΠΎ Π²ΡΠ΅ΠΌΡ Π»Π΅ΡΠ΅Π½ΠΈΡ Π±ΡΠ»ΠΈ ΠΎΡΠΌΠ΅ΡΠ΅Π½Ρ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠ½ΡΠ΅ Π΄Π»Ρ ΠΊΠ°ΠΆΠ΄ΠΎΠ³ΠΎ ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠ° ΠΏΠΎΠ±ΠΎΡΠ½ΡΠ΅ ΡΠ²Π»Π΅Π½ΠΈΡ. Π‘ΠΎΡΠ΅ΡΠ°Π½ΠΈΠ΅ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠΈ ΠΏΠ°ΡΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ Π’Π£Π ΠΏΡΠΎΡΡΠ°ΡΡ ΠΏΡΠΈ ΠΠΠΠ ΠΈ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠΎΠ³ΠΎ Π² ΠΏΠΎΡΠ»Π΅ΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΌ ΠΏΠ΅ΡΠΈΠΎΠ΄Π΅ ΠΌΠ΅Π΄ΠΈΠΊΠ°ΠΌΠ΅Π½ΡΠΎΠ·Π½ΠΎΠ³ΠΎ Π»Π΅ΡΠ΅Π½ΠΈΡ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΠ²Π°Π΅Ρ ΡΠΎΡ
ΡΠ°Π½Π΅Π½ΠΈΠ΅ Π°Π½ΡΠ΅Π³ΡΠ°Π΄Π½ΠΎΠΉ ΡΡΠΊΡΠ»ΡΡΠΈΠΈ Ρ ΠΏΠΎΠ΄Π°Π²Π»ΡΡΡΠ΅Π³ΠΎ Π±ΠΎΠ»ΡΡΠΈΠ½ΡΡΠ²Π° (89,5%) ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠ² ΡΡΠ΅Π΄Π½Π΅Π³ΠΎ Π²ΠΎΠ·ΡΠ°ΡΡΠ°, ΡΡΠΎ ΠΌΠΈΠ½ΠΈΠΌΠΈΠ·ΠΈΡΡΠ΅Ρ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ ΠΊΠ°ΡΠ΅ΡΡΠ²Π° ΠΆΠΈΠ·Π½ΠΈ Π΄Π°Π½Π½ΠΎΠΉ ΠΊΠ°ΡΠ΅Π³ΠΎΡΠΈΠΈ Π±ΠΎΠ»ΡΠ½ΡΡ
ΠΏΠΎΡΠ»Π΅ ΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΈ
Ways to increase adherence to antihypertensive therapy
With a high prevalence in the Russian population and insufficient effectiveness of treatment, hypertension remains a poorly controlled cardiovascular risk factor, including due to the low compliance of patients. Noncompliance is due to a large number of factors, some of which were studied in post-hoc analysis of the Russian observational STILβ and TRICOLOR studies. It demonstrated that fixed-dose combinations of antihypertensive drugs can make a significant contribution to solving such a complex problem as low compliance
Existence and stability of hole solutions to complex Ginzburg-Landau equations
We consider the existence and stability of the hole, or dark soliton,
solution to a Ginzburg-Landau perturbation of the defocusing nonlinear
Schroedinger equation (NLS), and to the nearly real complex Ginzburg-Landau
equation (CGL). By using dynamical systems techniques, it is shown that the
dark soliton can persist as either a regular perturbation or a singular
perturbation of that which exists for the NLS. When considering the stability
of the soliton, a major difficulty which must be overcome is that eigenvalues
may bifurcate out of the continuous spectrum, i.e., an edge bifurcation may
occur. Since the continuous spectrum for the NLS covers the imaginary axis, and
since for the CGL it touches the origin, such a bifurcation may lead to an
unstable wave. An additional important consideration is that an edge
bifurcation can happen even if there are no eigenvalues embedded in the
continuous spectrum. Building on and refining ideas first presented in Kapitula
and Sandstede (Physica D, 1998) and Kapitula (SIAM J. Math. Anal., 1999), we
show that when the wave persists as a regular perturbation, at most three
eigenvalues will bifurcate out of the continuous spectrum. Furthermore, we
precisely track these bifurcating eigenvalues, and thus are able to give
conditions for which the perturbed wave will be stable. For the NLS the results
are an improvement and refinement of previous work, while the results for the
CGL are new. The techniques presented are very general and are therefore
applicable to a much larger class of problems than those considered here.Comment: 41 pages, 4 figures, submitte
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