159,540 research outputs found
Nonlinearity-enhanced quantum sensing in Stark probes
No full textStark systems in which a linear gradient field is applied across a many-body system have recently been proposed for quantum sensing. Here, we explore sensing capacity of Stark probes, in both single-particle and many-body interacting systems, for estimating nonlinear forms of the gradient fields. Our analysis reveals that, this estimation can achieve super-Heisenberg scaling precision that grows linearly by increasing the nonlinearity. Specifically, we find a universal algebraic relation between the scaling of the precision and the degree of the nonlinearity. This universal behavior remains valid in both single-particle and many-body interacting probes and reflects itself in the properties of the phase transition from an extended to a localized phase, obtained through establishing a comprehensive finite-size scaling analysis. Considering a parabolic gradient potential composed of both linear and nonlinear fields, we used multiparameter estimation methodology to estimate the components of the gradient potential. The phase diagram of the system is determined in terms of both linear and nonlinear gradient fields showing how the nonlocalized phase turns into a localized one as the Stark fields increase. The sensing precision of both linear and nonlinear Stark fields follows the same universal algebraic relation that was found for the case of single parameter sensing. We demonstrate that simple and experimentally available measurements can reach the theoretical precision bounds. Finally, we show that quantum enhanced sensitivity is still achievable even when we incorporate the preparation time of the probe into our resource analysis
The Bayat mouth (language review, text, dictionary)
No full textAfyon iline bağlı Bayat ilçesinde ağız araştırması yapmaya karar verdikten sonra, 1998 yılı eylül ve ekim aylarında metinlerimizi derledik. Derlediğimiz metinleri Türk Dil Kurumu tarafından tavsiye edilen “Ağız Araştırmalarında Kullanılacak Fonetik Transkripsiyon alfabesi” ndeki sisteme göre yazıya geçirdik. Metinlerimizde yaptığımız ses bilgisi ve şekil bilgisi çalışmalarının sonucunda Bayat Merkez Ağzının Özelliklerini ortaya koymaya çalıştık. Bu özellikleri şöyle sıralayabiliriz:
1. #k >#ġ değişimi sık görülür.
2. r ile biten fiil kök ve gövdelerine gelen geniş zaman ekinde genellikle hece yutumu, bazen de r düşmesi görülür.
3. İstek kipinin 1. teklik kişi çekimi yaygın olarak kullanılır. Ek, ince sıradan kelimelerde açık e (ä), kalın sıradan kelimelerde ise uzun a (ā) şeklinde görülür.
4. Olumsuzluk eki ünlüsü, şimdiki zaman ekinden önce yaygın olarak uzun şekliyle görülür.
5. Şimdiki zaman eki -yu şekliyle yaygın olarak kullanılır.
6. k>ğ, h ünsüzlerinin düşmesiyle genellikle dar ünlüler genişlemiştir.After deciding local dialect searching in Bayat town that depends on Afyon, we collected our searches in september and in october in 1998. We wrote our searches according to the system of phonetic trascription alphabet (which will be used in local dialect searching) that is recommended by Turkish Linguistic Society. At the end of the phonetics and morphology searches, we tried to determine Bayat town local dialect features. These features can be numbered like these:
1. #k >#ġ changing is seen very often.
2. The verbs ending with “r” in simple present tense affix; it’s generally seen hablology in their roots and also sometimes seen “r” falling.
3. Firts personal subjunctive is used widely. Affix is seen in open e (ä) if the words have thin vowels, affix is seen long a (ā) if the words have thick vowels.
4. Necative particle vowel is seen widely with its long shape before present continuous affix.
5. Present continuous affix is used widely with its “-yu” shape.
6. When k > ğ, h consonants’ elision, generaly narrow vowels become wider
Naked-eye detection of morphine by Au@Ag nanoparticles-based colorimetric chemosensors
No full textIn this study, we report a novel and facile colorimetric assay based on silver citrate-coated Au@Ag nanoparticles (Au@AgNPs) as a chemosensor for the naked-eye detection of morphine (MOR). The developed optical sensing approach relied on the aggregation of Au@Ag NPs upon exposure to morphine, which led to an evident color variation from light-yellow to brown. Au@Ag NPs have been prepared by two different protocols, using high- and low-power ultrasonic irradiation. The sonochemical method was essential for the sensing properties of the resulting nanoparticles. This facile sensing method has several advantages including excellent stability, selectivity, prompt detection, and cost-effectiveness
Three-dimensional finite element analyses of functionally graded femoral prostheses with different geometrical configurations
No full textIn this work, functionally graded femoral prostheses (FGFPs) with different geometrical configurations are studied using three-dimensional finite element analysis. The FGFP consists of stainless steel-hydroxyapatite (SS 316L-HA) and titanium alloy-hydroxyapatite (Ti-HA) with various volume fraction gradient exponents n=0.0, 0.1, 0.5, and 1.0. This study is the first to consider an FGFP with a combination of different profiles and cross-sections in a non-bonded implant-bone interface. The results show that the strain energy density in the proximal metaphysis of the femur increases by more than 22% in the FGFP with different geometrical configurations, which correspond to a reduction in stress shielding and subsequently decrease bone resorption. Simultaneously, the interface stresses in the bone-implant contact region have limited variations for all combinations of profiles and cross-sections. Therefore, FGFP can be employed to introduce a new optimum design for femoral prosthesis with adjustable stiffness, which can decrease stress shielding and interface stress. This condition results in an increase in the total lifespan of the hip replacement. © 2014 Elsevier Ltd
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Non-Hermitian discrete time crystals
No full textDiscrete time crystals (DTCs) exhibit a special nonequilibrium phase of matter in periodically driven manybody systems with spontaneous breaking of time translational symmetry. The presence of decoherence generally enhances thermalization and destroys the coherence required for the existence of DTCs. In this paper, we devise a mechanism for establishing a stable DTC with period-doubling oscillations in an open quantum system that is governed by a properly tailored non-Hermitian Hamiltonian. We find a specific class of nonreciprocal couplings in our non-Hermitian dynamics which prevents thermalization through eigenstate ordering. This choice of non-Hermitian dynamics significantly enhances the stability of the DTC against imperfect pulses. Through a comprehensive analysis, we determine the phase diagram of the system in terms of pulse imperfection
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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