Correction of Arbitrary Errors in Population Inversion of Quantum Systems by Universal Composite Pulses

We introduce universal broadband composite pulse sequences for robust high-fidelity population inversion in two-state quantum systems, which compensate deviations in any experimental parameter (e.g. pulse amplitude, pulse duration, detuning from resonance, Stark shifts, unwanted frequency chirp, etc.) and are applicable with any pulse shape. We demonstrate the efficiency and universality of these composite pulses by experimental data on rephasing of atomic coherences in a $\text{Pr}^{3+}\text{:}\text{Y}_2\text{SiO}_5$ crystal

Experimental demonstration of composite stimulated Raman adiabatic passage

We experimentally demonstrate composite stimulated Raman adiabatic passage (CSTIRAP), which combines the concepts of composite pulse sequences and adiabatic passage. The technique is applied for population transfer in a rare-earth doped solid. We compare the performance of CSTIRAP with conventional single and repeated STIRAP, either in the resonant or the highly detuned regime. In the latter case, CSTIRAP improves the peak transfer efficiency and robustness, boosting the transfer efficiency substantially compared to repeated STIRAP. We also propose and demonstrate a universal version of CSTIRAP, which shows improved performance compared to the originally proposed composite version. Our findings pave the way towards new STIRAP applications, which require repeated excitation cycles, e.g., for momentum transfer in atom optics, or dynamical decoupling to invert arbitrary superposition states in quantum memories.Comment: 11 pages, 5 figure

Rephasing efficiency of sequences of phased pulses in spin-echo and light-storage experiments

We investigate the rephasing efficiency of sequences of phased pulses for spin echoes and light storage by electromagnetically induced transparency (EIT). We derive a simple theoretical model and show that the rephasing efficiency is very sensitive to the phases of the imperfect rephasing pulses. The obtained efficiency differs substantially for spin echoes and EIT light storage, which is due to the spatially retarded coherence phases after EIT light storage. Similar behavior is also expected for other light-storage protocols with spatial retardation or for rephasing of collective quantum states with an unknown or undefined phase, e.g., as relevant in single-photon storage. We confirm the predictions of our theoretical model by experiments in a Pr$^{3+}$:Y$_{2}$SiO$_{5}$ crystal

Universal Composite Pulses for Efficient Population Inversion with an Arbitrary Excitation Profile

We introduce a method to rotate arbitrarily the excitation profile of universal broadband composite pulse sequences for robust high-fidelity population inversion. These pulses compensate deviations in any experimental parameter (e.g. pulse amplitude, pulse duration, detuning from resonance, Stark shifts, unwanted frequency chirp, etc.) and are applicable with any pulse shape. The rotation allows to achieve higher order robustness to any combination of pulse area and detuning errors at no additional cost. The latter can be particularly useful, e.g., when detuning errors are due to Stark shifts that are correlated with the power of the applied field. We demonstrate the efficiency and universality of these composite pulses by experimental implementation for rephasing of atomic coherences in a $\text{Pr}^{3+}\text{:}\text{Y}_2\text{SiO}_5\:$ crystal.Comment: arXiv admin note: text overlap with arXiv:1403.120

Occurence of common dolphins (Delphinus delphis) in the Gulf of Trieste and the northern Adriatic Sea

1. The Mediterranean common dolphin (Delphinus delphis), considered to have been very common in the past, had undergone a dramatic decline across most of the basin by the end of 1970s. In the northern Adriatic Sea, one of the regions with most available historical information, the common dolphin is thought to have been the most common and abundant cetacean throughout most of the 20th century. However, by the end of 1970s, it had virtually disappeared from the region and is now considered generally absent from the entire Adriatic Sea. 2. This contribution summarizes the occurrence of common dolphins in the Gulf of Trieste and provides a brief review of published records in other parts of the Adriatic Sea. 3. Systematic boat surveys in the wider area of the Gulf of Trieste between 2002 and 2019 confirmed that the common bottlenose dolphin (Tursiops truncatus) is the only regularly occurring cetacean species in this area. Despite this, several records of common dolphins were documented in the Gulf of Trieste between 2009 and 2012, through sightings of live animals or recovery of dead stranded animals. 4. Dorsal fin markings allowed the photo‐identification of some of these, suggesting that at least four different live individuals (three adults and one calf) occurred here in recent times. Most cases involved single adult individuals, but one included a mother‐calf pair that was temporarily resident in a port for several months, a behaviour atypical for this species. Photo‐identification showed that the presumed mother had previously been sighted in the Ionian Sea in Greece, over 1,000 km from the Gulf of Trieste, making this the longest documented movement for this species worldwide. 5. At present, the common dolphin continues to be rare in the region.Publisher PDFPeer reviewe

Hymenolepidid Cestodes from Grebes (Aves, Podicipedidae) in Ukraine: the Genus Confluaria

Redescriptions of 5 species of the hymenolepidid cestodes from the genus Confluaria Ablasov in Spasskaja, 1966 recorded from grebes (Podicipedidae) in Ukraine are presented: Confluaria podicipina from Podiceps nigricollis; Confluaria furcifera from P. grisegena, P. cristatus and P. nigricollis; Confluaria pseudofurcifera (new geographical record) from P. cristatus; Confluaria capillaris from P. grisegena and P. nigricollis; Confluaria multistriata from Tachybaptus ruficollis. Confluaria krabbei sp. n. from T. ruficollis is described. It is differentiated from C. multistriata by possessing rostellar hooks with epiphyseal thickenings comprising both handle and guard and by the shorter cirrus-sac which does not reach the mid-line of the proglottis.Даны переописания 5 видов гименолепидид рода Confluaria Ablasov in Spasskaja, 1966, зарегистрированных у поганок в Украине: C. podicipina от Podiceps nigricollis; C. furcifera от P. nigricollis, P. grisеgena и P. cristatus; C. pseudofurcifera (регистрируется в Украине впервые) от P. cristatus; C. capillaris от P. grisеgena, P. nigricollis; C. multistriata от Tachybaptes ruficollis. Описан также новый вид Confluaria krabbei sp. n. от T. ruficollis, который дифференцируется от C. multistriata по наличию на крючьях хоботка больших эпифизарных утолщений, охватывающих как рукоятку, так и отросток корня, а также меньшей длине бурсы цирруса, не достигающей средней линии членика

Hymenolepidid Cestodes from Grebes (Aves, Podicipedidae) in Ukraine: the Genera Dollfusilepis and Parafimbriaria

A redescription of Dollfusilepis hoploporus (Dollfus, 1951) based on specimens from Podiceps cristatus in Ukraine (new geographical record) is presented. This species is also recorded from the same host species in Turkmenistan (new geographical record). Dollfusilepis grisegenicus Vasileva, Kornyushin, Genov, sp. n. from Podiceps grisegena is described. It differs from the type-species of Dollfusilepis hoploporus mainly by the presence of rosethornshaped spines on the protrusible poral part of the cirrus-sac. The generic diagnosis of Dollfusilepis Vasileva, Georgiev, Genov, 1998 is amended. Parafimbriaria micracantha Gulyaev, 1990 is redescribed on the basis of specimens from P. nigricollis in Ukraine (new geographical record).Дано переописание Dollfusilepis hoploporus (Dollfus, 1951) по екземплярам от Podiceps cristatus из Украины (регистрируется впервые). Этот же вид впервые зарегистрирован в Туркменистане у того же хозяина. Описан новый вид Dollfusilepis grisegenicus Vasileva, Kornyushin, Genov, sp. n. io Podiceps grisegena, который отличается от типового вида рода, Б. hoploporus, в основном наличием вооружения в виде шипиков на выдвигающейся поральной части бурсы цирруса. Уточнен диагноз рода DolfUsilepis Уаєііеуа, Оеощіеу, Оепоу, 1998. Переописана Parafimbriaria micracantha Gulyaev, 1990 по материалу от Podiceps nigricollis из Украины

Kinetics of CO2 hydrate formation from water frost at low temperatures: Experimental results and theoretical model

The gas hydrate growth from frostlike powders composed of micrometer-sized ice particles does not start with hydrate shell formation, because the initial hydrate film thickness established in earlier work exceeds the ice particle dimensions. In this limiting case, the ice grains are directly consumed by a growing nucleus created on the particle surface. The conventional Johnson-Mehl-Avrami-Kolmogorov (JMAK) model,(1)which considers (re-) crystallization reactions phenomenologically in terms of the constituent nucleation and subsequent growth processes, cannot be directly applied to the hydrate formation from frost due to the assumption of an infinitely large domain of crystallization. We present here a modified approach to account for the small particle sizes of the starting material and extend the existing theory of gas hydrate formation from monodisperse ice powders(3-5)to the low-temperature and low-ice-particle-size limit. This approach may also prove to be very useful for applying chemical reactions starting on the surface of nanomaterials. In situ neutron scattering was used to obtain the experimental degree of transformation as a function of temperature between 185 and 195 K. The data were analyzed with the modified JMAK model constrained by information from cryo-SEM and BET measurements. Based on the obtained activation energies for hydrate nucleation and growth, an estimate is given for the probability of formation of CO2 hydrates at conditions relevant for Mars; a direct reaction of CO2 gas with water frost is considered to be very unlikely on the Martian surface under current conditions. © 2011 American Chemical Society

Модернизация конструкции биологического лабораторного комплекса

Объектом модернизации в данной работе является конструкция биологического лабораторного комплекса. Цель: модернизация конструкции биологического лабораторного комплекса. Результатом процесса модернизации является конструкция комплекса в CAD системе SolidWorks. В ходе работы: модернизирована конструкция комплекса под заданные характеристики, разработан сборочный чертеж, спроектирован технологический процесс изготовления детали типа фланец.The object of modernization in this work is the construction of a biological laboratory complex. Purpose: modernization of the biological laboratory complex. The result of the modernization process is the design of the complex in the CAD system SolidWorks. In the course of work: the design of the complex has been modernized for the given characteristics, an assembly drawing has been developed, a technological process has been designed for manufacturing a flange type part