Bose-Einstein Condensation of Excitons: Reply to Tikhodeev's Criticism

The extended version of our reply to Comment on ``Critical Velocities in Exciton Superfluidity'' by S. G. Tikhodeev (Phys. Rev. Lett., 84 (2000), 3502 or from http://prl.aps.org/) is presented here. The principal question is discussed: does the moving exciton-phonon packet contain the coherent `nucleus', or the exciton-phonon condensate?Comment: 3 pages in LaTe

Constraint satisfaction parameterized by solution size

In the constraint satisfaction problem (CSP) corresponding to a constraint language (i.e., a set of relations) $\Gamma$, the goal is to find an assignment of values to variables so that a given set of constraints specified by relations from $\Gamma$ is satisfied. The complexity of this problem has received substantial amount of attention in the past decade. In this paper we study the fixed-parameter tractability of constraint satisfaction problems parameterized by the size of the solution in the following sense: one of the possible values, say 0, is "free," and the number of variables allowed to take other, "expensive," values is restricted. A size constraint requires that exactly $k$ variables take nonzero values. We also study a more refined version of this restriction: a global cardinality constraint prescribes how many variables have to be assigned each particular value. We study the parameterized complexity of these types of CSPs where the parameter is the required number $k$ of nonzero variables. As special cases, we can obtain natural and well-studied parameterized problems such as Independent Set, Vertex Cover, d-Hitting Set, Biclique, etc. In the case of constraint languages closed under substitution of constants, we give a complete characterization of the fixed-parameter tractable cases of CSPs with size constraints, and we show that all the remaining problems are W[1]-hard. For CSPs with cardinality constraints, we obtain a similar classification, but for some of the problems we are only able to show that they are Biclique-hard. The exact parameterized complexity of the Biclique problem is a notorious open problem, although it is believed to be W[1]-hard.Comment: To appear in SICOMP. Conference version in ICALP 201

Automation of the construction the Potier diagram using LabVIEW system design software

The paper describes the virtual instrument (software module) developed in the software development environment NI LabVIEW, which automatically constructs the Potier diagram based on the measurements results of the operation mode parameters of the synchronous machine.Приведено описание виртуального пробора (программного модуля) в среде разработки программного обеспечения NI LabVIEW выполняющего автоматическое построение диаграммы Потье по результатам измерений параметров режима работы синхронной машины

The crystallochemical informativeness of optical and Mossbauer spectra for ferromagnesian micas.

The ferromagnesian micas are common rock-forming minerals, which are used in geological, mineralogical and petrographic researches, while the low-iron varieties have technical uses. Deals with methods of obtaining crystallochemical information on micas, which is important from the scientific and practical viewpoints.-from Journal summar

Homogeneous nucleation of dislocations as bifurcations in a periodized discrete elasticity model

A novel analysis of homogeneous nucleation of dislocations in sheared two-dimensional crystals described by periodized discrete elasticity models is presented. When the crystal is sheared beyond a critical strain $F=F_{c}$, the strained dislocation-free state becomes unstable via a subcritical pitchfork bifurcation. Selecting a fixed final applied strain $F_{f}>F_{c}$, different simultaneously stable stationary configurations containing two or four edge dislocations may be reached by setting $F=F_{f}t/t_{r}$ during different time intervals $t_{r}$. At a characteristic time after $t_{r}$, one or two dipoles are nucleated, split, and the resulting two edge dislocations move in opposite directions to the sample boundary. Numerical continuation shows how configurations with different numbers of edge dislocation pairs emerge as bifurcations from the dislocation-free state.Comment: 6 pages, 4 figures, to appear in Europhys. Let

On Critical Velocities in Exciton Superfluidity

The presence of exciton phonon interactions is shown to play a key role in the exciton superfluidity. We apply the Landau criterion for an exciton-phonon condensate moving uniformly at zero temperature. It turns out that there are essentially two critical velocities in the theory. Within the range of these velocities the condensate can exist only as a bright soliton. The excitation spectrum and differential equations for the wave function of this condensate are derived.Comment: 7 pages, Latex; to be published in Phys.Rev.Lett (1997

СПЕКТРОФОТОМЕТРИЧЕСКОЕ ОПРЕДЕЛЕНИЕ ИОНОВ АММОНИЯ В БЕТОННЫХ СМЕСЯХ И БЕТОНАХ

In the last five years, the construction industry of several countries was faced with such a main and complex question as emission of gaseous ammonia into the indoor of residential buildings made of concrete. Consequently, the accumulation of ammonia in the air space of living quarters leads to their unsuitability. Therefore, there is a need to determine the ammonium ions in concrete mixtures before construction and in the walls of built buildings in order to find sources of ammonia emission. To determine ammonium ions in concrete mixtures and concrete the spectrophotometric techniques based on the indophenol-blue complex were developed. The first technique is designed for the express outside laboratory quality control of concrete mixtures and includes the step of ammonium ions extracting in aqueous phase followed by spectrophotometric determination. The second one is designed to establish the sources of ammonia in buildings constructed already and includes the step of headspace single-drop micro-extraction, which allows to eliminate multicomponent matrix interferences of concrete. The liner ranges are 0.2 – 5 mg/kg and 0.1 – 1 mg/kg respectively. Time of analyzes does not exceed 15 min.Key words: spectrophotometry, headspace micro extraction, concrete mixtures, concrete, ammonium ions.(Russian)DOI: http://dx.doi.org/10.15826/analitika.2014.18.2.008  I.I. Timofeeva, I.I. Khubaibullin, A.V. Bulatov, A.L. Moskvin Saint-Petersburg State University, Saint-Petersburg, Russian FederationВ последние пять лет строительная индустрия нескольких стран столкнулась с таким важным и сложным вопросом как выделение газообразного аммиака из стен монолитных новостроек, построенных из бетона. Как следствие, накопление в воздухе аммиака в ходе эксплуатации помещений приводит к их непригодности для использования по назначению. В связи с масштабностью данной проблемы существует потребность в определении ионов аммония в бетонных смесях на стадии строительства и в бетонных конструкциях уже построенных помещений с целью поиска источников выделения аммиака. Для решения этой проблемы были разработаны методики спектрофотометрического определения ионов аммония в бетонных смесях и бетонах, основанные на реакции образования индофенольного комплекса. Первая методика предназначена для экспрессного внелабораторного контроля качества бетонных смесей и включает стадию извлечения ионов аммония в водную фазу с последующим их спектрофотометрическим определением. Вторая методика – для установления источников выделения аммиака в уже построенных помещениях, включающая стадию парофазной микроэкстракции, которая позволяет полностью исключить мешающее влияние многокомпонентной матрицы бетона. Разработанные методики обеспечивают диапазоны определяемых содержаний от 0.2 до 5 и от 0.1 до 1 мг/кг. Время анализа не превышает 15 мин.Ключевые слова: спектрофотометрия, парофазная микроэкстракция, ионы аммония, бетонные смеси, бетоны.DOI: http://dx.doi.org/10.15826/analitika.2014.18.2.008

VALSARTAN IN EVERYDAY CLINICAL PRACTICE IN RUSSIA: ANTIHYPERTENSIVE EFFICACY AND INFLUENCE ON SEXUAL FUNCTION IN PATIENTS WITH ARTERIAL HYPERTENSION

Aim. To study antihypertensive efficacy and safety of valsartan-based therapy (Diovan, Novartis Pharma) as well as patient’s compliance and influence of treatment on several aspects of sexual function.Material and methods. 114 doctors from 81 medical institutions of Russia participated in this prospective multicenter observation study. 650 hypertensive patients (average age 53,9±0,4 y.o.) were enrolled. The evaluation of therapy efficacy was based on analysis of systolic (SBP) and diastolic (DBP) blood pressure (BP) changes. Safety and compliance of treatment was also analyzed. The evaluation of sexual function was performed with 5 universal questions selected form the International Index of Erectile Function. These questions could be asked in both men and women. The valsartan dose was 80-320 mg OD. A combination of the valsartan with hydrochlorothiazide (12,5-25 mg/d), amlodipine (5-10 mg/d) or any other antihypertensive was allowed.Results. Significant similar decrease of SBP and DBP was observed in smoking and non-smoking patients (37,5/18,5 and 37,6/15,9 mm Hg respectively, р<0,01 vs baseline). 312 patients (56,9% men, 43,1% women) completed sexual function survey. After 12 weeks of treatment the number of patients without sexual activity and with 1-2 successful sexual attempts in the last 4 weeks significantly decreased from 22 to 16% and from 44 to 30% respectively (р<0,05). Significant increase in the number of patients with 5-6 and 7-10 successful sexual attempts was observed (from 7 to 20% and from 0 to 7% respectively, р<0,05). The treatment resulted in significant increase in the number of patients, who characterized their sexual life satisfaction as “very satisfied” (from 11 to 25%, р<0,01).Conclusion. During the course of effective antihypertensive treatment there was a significant increase in sexual function and general satisfaction with sexual life in patients with arterial hypertension, which could have favorable long-term consequences in increased compliance to the antihypertensive therapy