679 research outputs found

    Оценка погрешности выделения сигнала из шума на основе синхронного детектирования

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    Объектом исследования является метод синхронного детектирования, его применение и оценка погрешностей при разных параметрах. Цель работы – анализ составляющих погрешности при выделении сигнала методом синхронного детектирования. В процессе исследования проводился анализ принципа синхронного детектирования, аналитический обзор средств измерений на основе синхронного детектирования. Также проводилась оценка составляющих погрешности при отклонении частот детектируемого и опорного сигнала, влияние некогерентности опорного сигнала, влияние не ортогональности опорных сигналов. В результате исследования были получены оценки составляющих погрешности при отклонении частот детектируемого и опорного сигнала, а также было выявлено влияние некогерентности опорного сигнала, влияние не ортогональности опорных сигналов. Экономическая эффективность/значимость работы: реализация данного научно-технического проекта, позволяет увеличить эффективность производства, с ресурсосберегающей стороны путем внедрения новых синхронных усилителей с меньшей погрешностью, это позволит производить измерения более точно.The object of the study is the method of synchronous detection, its application and estimation of errors in different parameters. The work purpose – the analysis of the error components when the selection signal by the method of synchronous detection. In the process of investigation the analysis of the principle of synchronous detection, analytical review of measurement tools based on synchronous detection. Also was evaluated the components of the error in the frequency deviation detected and the reference signal, the influence of the incoherence of the reference signal, the influence of orthogonality of a reference signal. The study produced estimates of the components of error in the frequency deviation detected and the reference signal, but also revealed the effects of incoherence of the reference signal, the influence of orthogonality of a reference signal. Economic efficiency and significance of the work: the implementation of this research project, allows to increase production efficiency, resource-saving hand through the introduction of new synchronous amplifiers with reduced error, this will allow to measure more precisely

    Optical control of internal electric fields in band-gap graded InGaN nanowires

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    InGaN nanowires are suitable building blocks for many future optoelectronic devices. We show that a linear grading of the indium content along the nanowire axis from GaN to InN introduces an internal electric field evoking a photocurrent. Consistent with quantitative band structure simulations we observe a sign change in the measured photocurrent as a function of photon flux. This negative differential photocurrent opens the path to a new type of nanowire-based photodetector. We demonstrate that the photocurrent response of the nanowires is as fast as 1.5 ps

    THE ROLE OF POST-MORTEM BIOCHEMISTRY IN THE FORENSIC MEDICAL DIAGNOSIS OF MECHANICAL INJURY (literature review)

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    Background. Mechanical trauma occupies one of the leading places in forensic medical examination. The main task of the expert, when conducting this kind of examination, is to provide a scientifically based answer to the questions of the pre-trial investigation bodies or the court, which relate not only to the determination of the mechanism of the injury, but also to the time period of its occurrence. Traditional methods of morphological research and methods of laboratory analyzes cannot always provide comprehensive information, especially in cases of determining the age of mechanical trauma in the early Post-mortem period. Therefore, new methods of biochemical research are being actively introduced into forensic medical practice. Aim: Analysis of the literature devoted to the application of various biochemical diagnostic methods in forensic medical practice to establish the antiquity of mechanical trauma. Results. In pathological conditions, such as, for example, trauma, certain molecular changes occur in the human body, which are associated with a systemic reaction to a stress factor and are manifested before the appearance of morphological changes in tissues and organs. Therefore, the use of biochemical research methods will significantly expand the possibilities of forensic diagnostics. The publication shows promising directions for the application of the biochemical method for forensic trauma diagnosis. Issues of establishing the statute of limitations for mechanical injuries are considered. Today, scientific studies of the body's stress state in cases of fatal injuries are becoming more and more common. Which is of great importance for forensic medical expert practice. Therefore, the role of manifestations of the body's systemic response to trauma is described. The role of natriuretic peptides, creatine kinase and procalcitonin in diagnosing the duration of the traumatic process is also shown. Conclusion. The relevance and practical significance of biochemical research for the forensic diagnosis of the time of occurrence of a mechanical injury, as well as the development of new diagnostic criteria for determining the body's systemic response to trauma, necessitated a deep and comprehensive study of the above problems

    Разработка технологического процесса изготовления детали «Опора»

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    Объектом исследования является "опора". Цель работы - решение задача по созданию эффективного технологического процесса изготовления детали. В данном работе, проектировен процесс изготовления детали.The object of research is "support." The purpose of the work is to solve the problem of creating an efficient technological process for manufacturing a part. In this work, the process of manufacturing the part is designed

    L00L and p00p entanglement

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    We demonstrate the generation of unbalanced two-photon entanglement in the Laguerre-Gaussian (LG) transverse-spatial degree-of-freedom, where one photon carries a fundamental (Gauss) mode and the other a higher-order LG mode with a non-zero azimuthal (\ell) or radial (pp) component. Taking a cue from the N00NN00N state nomenclature, we call these types of states LOOLLOOL (L00L) or p00pp00p-entangled. They are generated by shifting one photon in the LG mode space and combining it with a second (initially uncorrelated) photon at a beamsplitter, followed by coincidence detection. In order to verify two-photon coherence, we demonstrate a two-photon ``twisted'' quantum eraser, where Hong-Ou-Mandel interference is recovered between two distinguishable photons by projecting them into a rotated LG superposition basis. Using an entanglement witness, we find that our generated LOOLLOOL and p00pp00p states have fidelities of 95.31\% and 89.80\% to their respective ideal maximally entangled states. Besides being of fundamental interest, this type of entanglement will likely have a significant impact on tickling the average quantum physicist's funny bone.Comment: Written for submission to the AVS Quantum Science special issue in memory of Jon Dowlin

    Technical design and commissioning of the KATRIN large-volume air coil system

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    The KATRIN experiment is a next-generation direct neutrino mass experiment with a sensitivity of 0.2 eV (90% C.L.) to the effective mass of the electron neutrino. It measures the tritium β\beta-decay spectrum close to its endpoint with a spectrometer based on the MAC-E filter technique. The β\beta-decay electrons are guided by a magnetic field that operates in the mT range in the central spectrometer volume; it is fine-tuned by a large-volume air coil system surrounding the spectrometer vessel. The purpose of the system is to provide optimal transmission properties for signal electrons and to achieve efficient magnetic shielding against background. In this paper we describe the technical design of the air coil system, including its mechanical and electrical properties. We outline the importance of its versatile operation modes in background investigation and suppression techniques. We compare magnetic field measurements in the inner spectrometer volume during system commissioning with corresponding simulations, which allows to verify the system's functionality in fine-tuning the magnetic field configuration. This is of major importance for a successful neutrino mass measurement at KATRIN.Comment: 32 pages, 16 figure
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