1,720,964 research outputs found
Modeling of optically detected magnetic resonances in nitrogen - vacancy optical centers of diamond
No full textMaģistra darbā veikta optiski reģistrējamo magnētisko rezonanšu modelēšana ar 13C atomiem bagātinātu dimanta kristālu slāpekļa - vakanču (NV-) optiskajos centros.
NV- centriem tiešā tuvumā esošo 13C atomu kodolu spini sašķeļ NV- centru enerģētisko struktūru, radot potenciāli iespējamas Λ sistēmas, kurās var notikt apdzīvotības slazdošana
attiecībā pret mikroviļņu diapazona magnētiskā dipola pārejām NV- centra elektroniskajā pamatstāvoklī.
NV- centra ar apkārtējiem n 13C atomu kodoliem sistēmas enerģētiskā struktūra aprakstīta, izmantojot spina Hamlitoniāņa metodi.
Izveidota datorprogramma optiski reģistrējamo magnētisko rezonanšu modelēšanai.
Rezultātā iegūti optiski reģistrējamo magnētisko rezonanšu modelēti signāli, kas salīdzināti ar eksperimentāli iegūtajiem datiem.In this work optically detectable magnetic resonance modeling in diamond crystal, that is
enriched with 13C atoms, nitrogen - vacancy optical centers.
The spins of the 13C atoms that are in direct vicinity of the NV- center split the electronic
structure of the NV- center creating potentially possible Λ systems in which population trapping with respect to microwave band magnetic dipole transitions in the NV- centers electronic ground state can occur.
The energetic structure of the NV- center with surrounding n 13C atomic nuclei system is
described using the spin Hamiltonian method.
A computer program is created for the modeling of optically detectable magnetic resonances.
As a result optically detectable magnetic resonance signals are obtained and compared
with experimentally obtained data
Study of dark and bright states in real and hypothetical atomic systems
No full textTumšo stāvokļu veidošanās ir pamatā tādām parādībām kā elektromagnētiski inducētā
caurspīdība un lāzerģenerācija bez populācijas inversijas.
LU Lāzercentrā tiek pētītas magneto-optiskās rezonanses, kuru pamatā ir tumšo stāvokļu veidošanās atomārās sistēmās.
Bakalaura darba mērķis ir izpētīt tumšo stāvokļu veidošanās nosacījumus dažādās atomārās sistēmās, pie dažādi polarizētas ierosinošās gaismas.
Mērķa sasniegšanai izvirzītie uzdevumi ir speciālās literatūras analīze, datorprogrammas izveide tumšo stāvokļu pētīšanai, tumšo stāvokļu izpēte reālās un atbilstošās hipotētiskās atomārās sistēmās.
Rezultātā iegūti tumšo stāvokļu veidošanās nosacījumi divu līmeņu sistēmām.
Atslēgvārdi: tumšais stāvoklis, atoma Hamiltona matrica, lāzera inducēta pāreja, polarizēta gaismaThe formation of dark states is one of the main causes for electromagnetically induced transparency and laser generation without population inversion.
In the Laser Centre of the University of Latvia magneto-optical resonanses, that are mainly caused by the formation of dark states, are being studied.
The goal of this work to study the conditions of dark state formation in various atomic systems using various polarized exciting light.
The necessary tasks to achieve this goal are analysis of special literature, creation of a computer program for the study of dark states in real and corresponding hypothetical atomic systems.
As a result the conditions for the formation of dark states in two level systems have been obtained.
Keywords: dark state, atomic Hamilton matrix, laser induced transition, polarized ligh
The Work Contents of the Personnel Specialist in Latvia
No full textThe contents in the work of personnel specialist differ in organizations from one field to another. It continues to evolve with an emergence of new technologies and business methods, as well as with structural changes in the economy, both at a global and national level. However, the existing professional regulations of particular professions in Latvia has not been changed for almost 10 years, while the economy as well as the workforce appears to have changed. The aim of the paper is to illustrate what currently forms the contents of work of personnel specialist in Latvia. To achieve this, a study on trends in the work of personnel specialists has been conducted with an informative support of Latvian Association for People Management. The topics of daily activities and tasks, as well as individual features of personnel in various fields, including building, banking, manufacturing, IT, retail company, and public service companies have been included in the study. Overall, 18 personnel specialists from public and private sectors were interviewed. The results show that the classical model of human resource management is still popular, although some of the industries have adapted many or most of the cutting-edge approaches in the field, including flexible jobs and continuous employee support. Therefore, it is advised to update the existing documentation, including the professional regulation and university curricula, to meet the needs of the contemporary companies employing personnel specialists
Correlation between Individual Values and Job Satisfaction and Involvement for Different Groups of Employees
No full textPamatojoties uz Individuālo vērtību teoriju (Schwartz, 1992), pētījuma mērķis bija noskaidrot, vai pastāv sakarības starp individuālajām vērtībām, apmierinātību ar darbu un iesaisti dažādu profesiju grupu darbiniekiem. Pētījumā piedalījās 159 dažādu profesiju grupu darbinieki - vadītāji 30 (18,9%), vecākie speciālisti 26 (16,4%), speciālisti 64 (40,3%) un “Citi”, kas kopā sastāda 39 (24,5%). Pētījuma dalībnieki aizpildīja Portreta vērtību aptauju un Utrehtas iesaistes darbā skalu. Apmierinātības ar darbu kopumā novērtēšanai, atbildēja uz jautājumu “Lūdzu norādiet, cik apmierināts Jūs pašlaik jūtieties strādājot pašreizējā profesijā”. Iegūtie rezultāti parādīja, ka pašrealizācija ir izteiktāka vadītājiem atšķirībā no pārējām trīs profesiju grupām un hedonisms ir izteiktāks speciālistiem atšķirībā no profesijām, kuras apvienotas grupā “Cits”. Tāpat pastāv saistība starp labvēlību un visām iesaistes darbā skalām. Saistība tiek novērota arī starp universālismu un iedziļināšanos, kā arī starp drošību un darba sparu un iedziļināšanos.Based on Individual values theory (Schwartz, 1992), the question of this study is how correlations exist between individual values, job satisfaction and involvement for different groups of employees. The study involved 159 employees of different professional groups - managers 30 (18.9%), senior specialists 26 (16.4%), specialists 64 (40.3%) and “Others”, which makes up 39 (24.5%). Participants completed the The Portrait Values Questionnaire and Utrecht Work Engagement Scale. To determine job satisfaction in general, participants answered the question "Please indicate how satisfied you at the moment feel working in your current profession". The results showed that self-direction is higher for managers unlike to the other three groups of professions and hedonism is higher for specialists unlike to professions in the group “Other”. Benevolence correlate with all engagement scales. Correlate is also between universalism and absorption, as well as between security and vigor and dedication
Quantum Random Number Generation Using NV Center Fluorescence
No full textŠī darba mērķis ir izveidot iekārtu, kas spēj ģenerēt kvantu gadījuma skaitļus izmantojot NV centru fluorescenci. Tiek pielietots augstas skaitliskās apertūras objektīvs un konfokālā mikroskopija, lai sasniegtu augstu izšķirtspēju NV centru ierosināšanā un izšķiršanā dimanta kristālā tuvu tā virsmai. Darba ietveros tika iegūti divi galvenie rezultāti: pirmais bija augstas izšķirtspējas NV centru fluorescences kartes, pēc kurām varēs noteikt NV centru izkārtojumu dimantā un otrais, iegūt kvantu gadījuma skaitļus, bija nepārliecinošs rezultāts, jo tehnisku limitāciju dēļ nevar veikt kvalitatīvus secinājumus par iegūtajiem rezultātiem.The main goal of this work is to create a device for quantum random number generation using NV center fluorescence. To achieve the goal, a high numerical aperture objective and confocal microscopy are used to ensure high resolution for excitation of NV centers near the surface of the diamond. Two main results of the experiment are mapping a high resolution NV center fluorescence map, from which individual NV centers can be identified, and generating quantum random numbers which gave uncertain resaults because of technical limitations of the used single photon detectors
Relationship between Coping strategies for stress and Personal Growth, depending on the Perceived stress and the Level of Inner Motivation
No full textPētījuma mērķis bija noskaidrot un izvērtēt stresa pārvarēšanas stratēģiju saistību ar pašizaugsmi atkarībā no uztvertā stresa un iekšējās motivācijas līmeņa. Pētījumā piedalījās 232 dalībnieki vecumā no 19 līdz 63 gadiem (M=34,35; SD=10,62). Pētījuma ietvarā tika veikta personīgās izaugsmes iniciatīvas aptaujas lingvistiskā adaptācija un izmantotas jau pieejamās aptaujas: “Stresa pārvarēšanas stratēģiju aptauja”; “Uztvertā stresa skala”; “Iekšējās motivācijas aptauja”. Pētījumā tika noskaidrots, ka pastāv statistiski nozīmīga pozitīva saistība starp stresa pārvarēšanas stratēģijām un pašizaugsmi dažādos uztvertā stresa un iekšējās motivācijas līmeņos, un moderatora mainīgie ietekmē stresa stratēģiju izvēli. Tika secināts, ka pašizaugsmes veicināšanai būtiskākā ir aktīvas pārvarēšanas stratēģija un to papildina pārējās stratēģijas.The objective of the study is to clarify and assess the correlation of coping strategies with personal growth depending on perceived stress and the level of internal motivation. The study sample consisted of 232 participants aged from 19 to 63 (M=34.35; SD=10.62). Within the framework of the study, a linguistic adaptation of the Personal Growth Initiative Scale – II, (Robitschek, 2008) was performed and the following surveys were used: The COPE Inventory; Perceived Stress Scale; Intrinsic Motivation Inventory. It was determined during the study that a statistically significant positive correlation exists between stress management strategies and personal growth at different levels of stress and internal motivation, and moderator variables affect the selection of stress strategies. The conclusion was made that an active coping strategy is the most important strategy for the promotion of personal growth, and other strategies are used to supplement it
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
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