A new class of non-Hermitian Hamiltonians with real spectra

We construct a new class of non-Hermitian Hamiltonians with real spectra. The Hamiltonians possess one explicitly known eigenfunction.Comment: 6 page

General approach to potentials with two known levels

We present the general form of potentials with two given energy levels $E_{1}$, $E_{2}$ and find corresponding wave functions. These entities are expressed in terms of one function $\xi (x)$ and one parameter $\Delta E=E_{2}$-$E_{1}$. We show how the quantum numbers of both levels depend on properties of the function $\xi (x)$. Our approach does not need resorting to the technique of supersymmetric (SUSY) quantum mechanics but automatically generates both the potential and superpotential.Comment: 14 pages, REVTeX 3.0. In v.2 misprints and inaccuracies in presentation corrected, discussion of 3-dim. case added. In v.3 misprint in eq. 41, several typos and inaccuracies in English corrected. To be published in J. of Phys. A: Math. Ge

Mandatory certification in China

Китай является второй экономикой мира и крупнейшим импортером и экспортером продукции. Сведения о системе обязательной сертификации, действующей в Китае и распространяющейся как на произведенную в Китае, так и на введенную продукцию в Китай весьма актуальны. В статье рассмотрены основные положения системы обязательной сертификации, действующей в КитаеChina is the world's second largest economy and largest importer and exporter. Information about the system of mandatory certification of operating in China and spread as produced in China and introduced products to China is very relevant. The article describes the main provisions of the sys-tem of mandatory certification of operating in Chin

The level of compliance of Russian and European rails standards on groups of indicators: the design and dimensions of rails

It is proved that the level of compliance of national and international standards determines the competitiveness of products. GOST R 51685–2013 «Railway rails. General technical conditions» is a new stage in the struggle for the competitiveness of domestic rails. The level of compliance of requirements imposed on the rails in the national standard GOST R 51685–2013 and the European Standard EN 13674–1–2011on the group of indicators: design and dimensions of the rails on the four-point of scale comparison is comparedДоказывется, что уровень соответствия требований национальных и международных стандартов определяет конкурентоспособность продукции. Утверждается, что ГОСТ Р 51685–2013 «Рельсы железнодорожные. Общие технические условия» – новая ступень в борьбе за конкурентоспособность отечественных рельсов. Сравнивается уровень соответствия требований, предъявляемых к рельсам, в национальном стандарте ГОСТ Р 51685–2013 и европейском стандарте EN 13674–1–2011, по группе показателей: конструкция и размеры рельсов по четырехбалльной шкале сравнени

Technical Regulations of the Customs Union

The attention to policy issues in the field of technical regulation within the framework of regional economic associations is paid. It is noted that in the course of economic integration there is a need of development of uniform requirements to safety. The statistics of introduction of technical regulations of the Customs union from 2011 to 2015 is analyzedУделяется внимание вопросам политики в области технического регулирования в рамках региональных экономических объединений. Отмечается, что в процессе экономической интеграции возникает необходимость разработки единых требований по безопасности. Анализируется статистика внедрения технических регламентов Таможенного союза с 2011 по 2015 гг

Suppression of electron spin relaxation in Mn-doped GaAs

We report a surprisingly long spin relaxation time of electrons in Mn-doped p-GaAs. The spin relaxation time scales with the optical pumping and increases from 12 ns in the dark to 160 ns upon saturation. This behavior is associated with the difference in spin relaxation rates of electrons precessing in the fluctuating fields of ionized or neutral Mn acceptors, respectively. For the latter the antiferromagnetic exchange interaction between a Mn ion and a bound hole results in a partial compensation of these fluctuating fields, leading to the enhanced spin memory.Comment: 4 pages, 4 figure

Assessment of the reliability of the locomotive based on statistical methods of quality management

The lack of reliability of the diesel locomotive operation leads to a decrease in the technical and economic efficiency of using the locomotive service of the enterprise. During the experiment which aimed at assessing the reliability of repair and maintenance of a diesel locomotive in one of the railway divisions of OJSC "Russian Railways", it was found that the failures may be distributed by types of equipment, based on the failures for 12 months of 2017. Statistical quality management methods were used to identify the most problematic types of locomotive equipment and specific causes of failures. © Published under licence by IOP Publishing Ltd

Dynamics of changes in tube standards

The issues of the use of standards in pipe industry as one of the critical segments of the metallurgical complex are considered. During the period from 2002 to 2014 the base of tube standards was updated by more than 30%. The introduction of a new standard for tube products entails a change in the existing base of standardsРассматриваются вопросы применения стандартов в трубной отрасли как одном из ответственных сегментов металлургического комплекса. Показано, что за период с 2002 по 2014 гг. база стандартов на трубную продукцию была обновлена более чем на 30 %. Оценен масштаб необходимых изменений в существующей базе стандартов на стальные трубы при введении в действие нового стандарта ГОСТ 31447–201

Nuclear spin driven quantum relaxation in LiY_0.998Ho_0.002F_4

Staircase hysteresis loops of the magnetization of a LiY_0.998Ho_0.002F_4 single crystal are observed at subkelvin temperatures and low field sweep rates. This behavior results from quantum dynamics at avoided level crossings of the energy spectrum of single Ho^{3+} ions in the presence of hyperfine interactions. Enhanced quantum relaxation in constant transverse fields allows the study of the relative magnitude of tunnel splittings. At faster sweep rates, non-equilibrated spin-phonon and spin-spin transitions, mediated by weak dipolar interactions, lead to magnetization oscillations and additional steps.Comment: 5 pages, 5 eps figures, using RevTe