中低纬电离层暴的统计分析与经验建模

As a key issue of ionospheric weather study, systemic studies on ionospheric storms can not only further improve our understanding of the response of the ionosphere to solar and geomagnetic disturbances, but also help us to reveal the chemical, dynamic and electro-dynamic mechanisms during storms. Empirical modelling for regional ionospheric storm is also very useful, because it can provide us with tools and references for the forecasting and further practical application of ionospheric activity. In this thesis, we focus on describing and forecasting of ionospheric storms at middle and low latitudes. The main points of my investigations are listed as follows. (1) By using magnetic storms during the period over 50 years, the dependence of the type, onset time and time delay of the ionospheric storms on magnetic latitude, season and local time at middle and low latitudes in the East-Asian sector are studied. The results show that the occurrences of the types of ionospheric disturbances differ in latitude and season. The onset of the ionospheric storms depends on local time. At middle latitudes, most negative phase onsets are within the local time interval from night to early morning, and they rarely occurred in the local noon and afternoon sectors. At low latitudes, positive phases commence most frequently in the daytime sector as well as pre-midnight sector. The average time delays for both the positive and negative ionospheric storms increase with descending latitudes. The time delay has significant dependence on the local time of main phase onset (MPO). The time delay of positive response is shorter for daytime MPO and longer for night-time MPO, whereas the opposite applies for negative response. (2) Based on some previous researches, a primary empirical model for mid-latitude ionospheric disturbance is set up. By fitting to the observed data, we get a high accuracy with a mean RMSE of only 12-14% in summer and equinox. The model output has been compared with the output of STORM model, and the results show that, our model is much better than STORM in summer and a little better for some mid-latitude stations at equinox. Especially, for the type of two-step geomagnetic storm, our model can present twice descending of foF2 very well. In addition, our model can forecast positive ionospheric storms.

通过第一性原理计算研究内地核的结构与成分

The determination of the composition and structure of the Earth’s inner core has long been the major subject in the study of the Earth’s deep interior. It’s widely believed that the Earth’s core is formed by iron with a fraction of nickel. However, light elements must exist in the inner core because the earth core is less dense than pure iron-nickel alloy (~2-3% in the solid inner core and ~6-7% in the liquid outer core). The questions are what and how much light element is there in the iron-nickel alloy. Besides the composition, the crystal structure of the iron with or without light element is also not well known. According to the seismological observations, the sound waves propagate 3-4% faster along the spin axis than in the equatorial plane. That means the inner core is anisotropic. The densest structure of iron-nickel alloy should be h.c.p structure under the very high pressures. However, the h,c,p structure does not propagate waves anisotropic ally. Then what is the structure of the iron-nickel alloy or the iron-nickle-light element alloy. In this study, we tried to predict the composition and the structure of the inner core through ab initio calculation of the Gibbs free energy, which is a function of internal energy, density and entropy. We conclude that the h.c.p structure is more stable than the b.c.c structure under high pressure and 0 K, but with the increase of temperature, the free energy of the b.c.c structure is decreasing much faster than the h.c.p structure caused by the vibration of the atomics, so the b.c.c structure is more stable at high temperatures. With the addition of light elements (S or Si or both), the free energy of b.c.c. decreases even faster, about 3at% of Si not only explains why the inner core is about 2-3 % lighter than the iron-nickle alloy, but also reasons why the inner core is anisotropic, since the b.c.c. structure becomes more stable than the h.c.p structure at 5500-6000K and b.c.c. is anisotropic in propagating seismic waves. Therefore, we infer that the inner core of the earth is formed by b.c.c iron and a fraction of nickel plus ~3at.% Si, with a temperature higher than 5500K, which is consistent with the studies from other approaches.

A homogeneous DNA hybridization system by using a new luminescence terbium chelate

Homogeneous DNA hybridization assay based on the luminescence resonance energy transfer (LRET) from a new luminescence terbium chelate, N,N,N-1,N-1-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-phenylpyridine]tetrakis(acetic acid) (BPTA)-Tb3+ (lambda(ex) = 325 nm and lambda(em) = 545 nm) to an organic dye, Cy3 (A,. = 548 nm and A,. = 565 nm), has been developed. In the system, two DNA probes whose sequences are complementary to the two different consecutive sequences of a target DNA are used; one of the probes is labeled with the Tb3+ chelate at the T-end, and the other is with Cy3 at the 5'-end. Labeling of the Tb3+ chelate is accomplished via the linkage of a biotin-labeled DNA probe with the Tb3+ chelate-labeled streptavidin. Strong sensitized emission of Cy3 was observed upon excitation of the Tb3+ chelate at 325 run, when the two probe DNAs were hybridized with the target DNA. The sensitivity of the assay was very high compared with those of the previous homogeneous-format assays using the conventional organic dyes; the detection limit of the present assay is about 30 pM of the target DNA strand.

Tracing the reactive melting of glass-forming silicate batches by in situ Na-23 NMR

Winter, Rudolf; Jones, A.R.; Florian, P.; Massiot, D., (2005) 'Tracing the reactive melting of glass-forming silicate batches by in situ Na-23 NMR', Journal of Physical Chemistry B 109(10) pp.4324-4332 RAE2008

Qualidade de Vida, Vinculação e Resiliência em adolescentes institucionalizados

Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para a obtenção do grau de Mestre em Psicologia, ramo de Psicologia Clínica e da Saúde

All-optical modulation converter for on-off keying to duobinary and alternate-mark inversion at 42.6 Gbps

Advanced modulation formats have become increasingly important as telecoms engineers strive for improved tolerance to both linear and nonlinear fibre-based transmission impairments. Two important modulation schemes are Duobinary (DB) and Alternate-mark inversion (AMI) [1] where transmission enhancement results from auxiliary phase modulation. As advanced modulation formats displace Return-to-zero On-Off Keying (RZ-OOK), inter-modulation converters will become increasingly important. If the modulation conversion can be performed at high bitrates with a small number of operations per bit, then all-optical techniques may offer lower energy consumption compared to optical-electronic-optical approaches. In this paper we experimentally demonstrate an all-optical system incorporating a pair of hybrid-integrated semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (MZI) gates which translate RZ-OOK to RZ-DB or RZ-AMI at 42.6 Gbps. This scheme includes a wavelength conversion to arbitrary output wavelength and has potential for high-level photonic integration, scalability to higher bitrates, and should exhibit regenerative properties [2].

Synthesis, characterisation and applications of group IV nanocrystals

Group IV materials such as silicon nanocrystals (Si NCs) and carbon quantum dots (CQDs) have received great attention as new functional materials with unique physical/chemical properties that are not found in the bulk material. This thesis reports the synthesis and characterisation of both types of nanocrystal and their application as fluorescence probes for the detection of metal ions. In chapter 2, a simple method is described for the size controlled synthesis of Si NCs within inverse micelles having well defined core diameters ranging from 2 to 6 nm using inert atmospheric synthetic methods. In addition, ligands with different molecular structures were utilised to reduce inter-nanocrystal attraction forces and improve the stability of the NC dispersions in water and a variety of organic solvents. Regulation of the Si NCs size is achieved by variation of the surfactants and addition rates, resulting high quality NCs with standard deviations (σ = Δd/d) of less than 10 %. Large scale production of highly mondisperse Si NC was also successfully demonstrated. In chapter 3, a simple solution phase synthesis of size monodisperse carbon quantum dots (CQDs) using a room temperature microemulsion strategy is demonstrated. The CQDs are synthesized in reverse micelles via the reduction of carbon tetrachloride using a hydride reducing agent. CQDs may be functionalised with covalently attached alkyl or amine monolayers, rendering the CQDs dispersible in wide range of polar or non-polar solvents. Regulation of the CQDs size was achieved by utilizing hydride reducing agents of different strengths. The CQDs possess a high photoluminescence quantum yield in the visible region and exhibit excellent photostability. In chapter 4, a simple and rapid assay for detection of Fe3+ ions was developed, based on quenching of the strong blue-green Si NC photoluminescence. The detection method showed a high selectivity, with only Fe3+ resulting in strong quenching of the fluorescence signal. No quenching of the fluorescence signal was induced by Fe2+ ions, allowing for solution phase discrimination between the same ion in different charge states. The optimised sensor system showed a sensitive detection range from 25- 900 μM and a limit of detection of 20.8 μM

TRADITION AND INNOVATION: ANALYSIS AND PERFORMANCE OF SELECTED COMPOSITIONS FOR VIOLONCELLO BY HEITOR VILLA-LOBOS

Brazilian composer Heitor Villa-Lobos (1887-1959) began his musical career as a cellist. When he was only twelve years old, it became imperativeupon the sudden and untimely death of his fatherthat the young Villa-Lobos earn money as a cellist to provide financial support for his mother and sisters. Villa-Lobos's intimate relationship with the cello eventually inspired him to compose great music for this instrument. This dissertation explores both the diversity of compositional technique and the evolution of style found in the music for cello written by Villa-Lobos. The project consists of two recorded recital performances and a written document exploring and analyzing those pieces. In the study of the music of Villa-Lobos, it is of great interest to consider the music's traditional European elements in combination (or even juxtaposition) with its imaginative and sometimes wildly innovative Brazilian character. His early works were greatly influenced by European Romantic composers such as Robert Schumann, Frédéric Chopin, and the virtuoso cellist/composer David Popper (whom Villa-Lobos idolized). Later, Villa-Lobos flourished in a newfound compositional independence and moved away from Euro-romanticism and toward the folk music of his Brazilian homeland. It is intriguing to experience this transition through an exploration of his cello compositions. The works examined and performed in this dissertation project are chosen from among the extensive number of Villa-Lobos's cello compositions and are his most important works for cello with piano, cello with another instrument, and cello with orchestra. The chosen works demonstrate the evolving range and combination of characteristic elements found in Villa-Lobos's compositional repertoire.

Aging African American Women and the Impact of Positive Psychological Factors on Quality of Life

Aging African-American women are disproportionately affected by negative health outcomes and mortality. Life stress has strong associations with these health outcomes. The purpose of this research was to understand how aging African American women manage stress. Specifically, the effects of coping, optimism, resilience, and religiousness as it relates to quality of life were examined. This cross-sectional exploratory study used a self-administered questionnaire and examined quality of life in 182 African-American women who were 65 years of age or older living in senior residential centers in Baltimore using convenience sampling. The age range for these women was 65 to 94 years with a mean of 71.8 years (SD = 5.6). The majority (53.1%) of participants completed high school, with 23 percent (N = 42) obtaining college degrees and 19 percent (N = 35) holding advanced degrees. Nearly 58 percent of participants were widowed and 81 percent were retired. In addition to demographics, the questionnaire included the following reliable and valid survey instruments: The Brief Cope Scale (Carver, Scheier, & Weintraub, 1989), Optimism Questionnaire (Scheier, Carver, & Bridges, 1994), Resilience Survey (Wagnild & Young, 1987), Religiousness Assessment (Koenig, 1997), and Quality of Life Questionnaire (Cummins, 1996). Results revealed that the positive psychological factors examined were positively associated with and significant predictors of quality of life. The bivariate correlations indicated that of the six coping dimensions measured in this study, planning (r=.68) was the most positively associated with quality of life. Optimism (r=.33), resilience (=.48), and religiousness (r=.30) were also significantly correlated with quality of life. In the linear regression model, again the coping dimension of planning was the best predictor of quality of life (beta = .75, p <.001). Optimism (beta = .31, p <.001), resilience (beta = .34, p, .001) and religiousness (beta = .17, p <.01) were also significant predictors of quality of life. It appears as if positive psychology plays an important role in improving quality of life among aging African-American women.

INNOVATIONS IN FRENCH CHAMBER MUSIC AND MÉLODIE (1886 – 1962) – A COLLABORATIVE PIANIST’S PERSPECTIVE

French chamber music in the last quarter of the nineteenth century displayed significant advances in musical innovations and technical developments. As the Parisian public began to favor instrumental music and mélodie over opera, vocal and chamber music with piano became one of the main genres to express French composers’ creativity and individuality. The composers Franck, Debussy, Fauré, Duparc, Ravel, Chausson and Poulenc were the major contributors to this unusually creative period in French music. French mélodies of this period blend precision with lyricism, and demand the performer’s elegance and wit. They show careful settings of the French language’s rhythmic subtleties and increased expressiveness in and importance of the piano accompaniment. The chamber works of this period demanded superior pianistic and instrumental virtuosity while displaying wide ranges of sonority, multiple tone colors, and rhythmic fluidity. The three recitals which comprise this dissertation project were performed at the University of Maryland Gildenhorn Recital Hall on 27 October 2006, All Nations Mission Church (Dayton, NJ) on 5 December 2009, and the Leah M. Smith Lecture Hall of the University of Maryland on 11 May 2010. The repertoire included Poulenc’s Sonata for Oboe and Piano (1962) with oboist Yeongsu Kim, French mélodies by Fauré, Chausson, Debussy, Ravel and Duparc with soprano Jung-A Lee and baritone Hyun-Oh Shin, Poulenc’s Sextet for Piano, Flute, Oboe, Clarinet, Bassoon and Horn (1932-1939) with flutist Katrina Smith, clarinetist Jihoon Chang, bassoonist Erich Heckscher, hornist Heidi Littman and oboist Yeongsu Kim, Debussy’s Sonata for Cello and Piano (1915) with cellist Ji-Sook Shin, Poulenc’s Sonata for Violin and Piano (1942-1949) with violinist Ji-Hee Lim, Franck’s Sonata for Violin and Piano (1886) with violinist Na-Young Cho, Ravel’s Piano Trio (1915) with cellist Ji-Sook Shin and violinist Yu-Jeong Lee and Ravel’s Sonata for Violin and Piano (1927) with violinist Yu-Jeong Lee. The recitals were recorded on compact discs and are archived within the Digital Repository at the University of Maryland (DRUM).

Road Traffic Injury Prevention Initiatives: A Systematic Review and Metasummary of Effectiveness in Low and Middle Income Countries.

BACKGROUND: Road traffic injuries (RTIs) are a growing but neglected global health crisis, requiring effective prevention to promote sustainable safety. Low- and middle-income countries (LMICs) share a disproportionately high burden with 90% of the world's road traffic deaths, and where RTIs are escalating due to rapid urbanization and motorization. Although several studies have assessed the effectiveness of a specific intervention, no systematic reviews have been conducted summarizing the effectiveness of RTI prevention initiatives specifically performed in LMIC settings; this study will help fill this gap. METHODS: In accordance with PRISMA guidelines we searched the electronic databases MEDLINE, EMBASE, Scopus, Web of Science, TRID, Lilacs, Scielo and Global Health. Articles were eligible if they considered RTI prevention in LMICs by evaluating a prevention-related intervention with outcome measures of crash, RTI, or death. In addition, a reference and citation analysis was conducted as well as a data quality assessment. A qualitative metasummary approach was used for data analysis and effect sizes were calculated to quantify the magnitude of emerging themes. RESULTS: Of the 8560 articles from the literature search, 18 articles from 11 LMICs fit the eligibility and inclusion criteria. Of these studies, four were from Sub-Saharan Africa, ten from Latin America and the Caribbean, one from the Middle East, and three from Asia. Half of the studies focused specifically on legislation, while the others focused on speed control measures, educational interventions, enforcement, road improvement, community programs, or a multifaceted intervention. CONCLUSION: Legislation was the most common intervention evaluated with the best outcomes when combined with strong enforcement initiatives or as part of a multifaceted approach. Because speed control is crucial to crash and injury prevention, road improvement interventions in LMIC settings should carefully consider how the impact of improvements will affect speed and traffic flow. Further road traffic injury prevention interventions should be performed in LMICs with patient-centered outcomes in order to guide injury prevention in these complex settings.

Modelling induction skull melting design modifications

Induction Skull Melting (ISM) is a technique for heating, melting, mixing and, possibly, evaporating reactive liquid metals at high temperatures with a minimum contact at solid walls. The presented numerical modelling involves the complete time dependent process analysis based on the coupled electromagnetic, temperature and turbulent velocity fields during the melting and liquid shape changes. The simulation model is validated against measurements of liquid metal height, temperature and heat losses in a commercial size ISM furnace. The observed typical limiting temperature plateau for increasing input electrical power is explained by the turbulent convective heat losses. Various methods to increase the superheat within the liquid melt, the process energy efficiency and stability are proposed.

The Application Of Radioisotopes In The Study Of Estuarine Sedimentary Processes

The spatial and temporal distributions of some radionuclides in effluents originating from the British Nuclear Fuels Ltd (BNFL) reprocessing plant at Windscale, which are released into the Irish Sea, have been studied in sediments at 16 sites in the salt marsh region near Newbiggin on the Esk estuary Cumbria, England. The concentration of non-conservative radionuclides in surface sediments of the area cannot be described by a single parameter, but there is a high correlation with organic C, Cu, Al and the Si : Al ratio with particle size. The preservation of the historical record of the BNFL effluents in the Esk sediments is dependent on the hydrology of the area, as it effects such processes as accretion, erosion and remixing. From the 106Ru and 210Po concentrations and the 137Cs : 134Cs ratio in the sediment profiles with depth, we have identified these processes. Sedimentation rates at sites of accretion vary between 0·5 and 3 cm year−1. However, at some sites they appear to be much higher, approximately 6 cm year−1 in the top 10 cm, but they are not consistent throughout the depth profiles. This may be a true reflection of variable accretion related to sediment type, or one which is influenced by surficial mixing. Some cores showed evidence of continuous accretion but no significant radioactivity was detected at depths below 35–40 cm, indicating an overall sedimentation rate of approximately 1·5 cm year−1 for the 25–30-year period since BNFL effluents first entered the Irish Sea.

Parameterisation of bivalve functional traits for mechanistic eco-physiological dynamic energy budget (DEB) models

Mechanistic models such as those based on dynamic energy budget (DEB) theory are emergent ecomechanics tools to investigate the extent of fitness in organisms through changes in life history traits as explained by bioenergetic principles. The rapid growth in interest around this approach originates from the mechanistic characteristics of DEB, which are based on a number of rules dictating the use of mass and energy flow through organisms. One apparent bottleneck in DEB applications comes from the estimations of DEB parameters which are based on mathematical and statistical methods (covariation method). The parameterisation process begins with the knowledge of some functional traits of a target organism (e. g. embryo, sexual maturity and ultimate body size, feeding and assimilation rates, maintenance costs), identified from the literature or laboratory experiments. However, considering the prominent role of the mechanistic approach in ecology, the reduction of possible uncertainties is an important objective. We propose a revaluation of the laboratory procedures commonly used in ecological studies to estimate DEB parameters in marine bivalves. Our experimental organism was Brachidontes pharaonis. We supported our proposal with a validation exercise which compared life history traits as obtained by DEBs (implemented with parameters obtained using classical laboratory methods) with the actual set of species traits obtained in the field. Correspondence between the 2 approaches was very high (>95%) with respect to estimating both size and fitness. Our results demonstrate a good agreement between field data and model output for the effect of temperature and food density on age-size curve, maximum body size and total gamete production per life span. The mechanistic approach is a promising method of providing accurate predictions in a world that is under in creasing anthropogenic pressure.

Self-Management of Chronic Pain: Interventions, Strategies, Barriers, and Facilitators

Background & Purpose: Chronic pain is a prevalent chronic condition for which the best management options rarely provide complete relief. Individuals with chronic pain with neuropathic characteristics (NC) report more severe pain and experience less relief from interventions. Little is known about current self-management practices. The purpose of this dissertation was to inform self-management of chronic pain with and without NC at the individual, health system, and policy levels using the Innovative Care for Chronic Conditions Framework. Methods: The study included a systematic search and review and cross-sectional survey. The review evaluated the evidence for chronic pain self-management interventions and explored the role of health care providers in supporting self-management. The survey was mailed to 8,000 randomly selected Canadians in November 2011, and non-respondents were followed-up in May 2012. Screening questions were included for both chronic pain and NC. The questionnaire captured pain descriptions, self-management strategies, and self-management barriers, and facilitators. Results: Findings of the review suggested that self-management interventions are effective in improving pain and health outcomes. Health care professionals provided self-management advice and referred individuals to self-management interventions. The questionnaire was completed by 1,520 Canadians. Those with chronic pain (n=710) identified primary care physicians as the most helpful pain management professional. Overall, use of non-pharmaceutical medical self-management strategies was low. While use positive emotional self-management strategies was high, individuals with NC were more likely to use negative emotional self-management strategies compared to those without NC. Multiple self-management barriers and facilitators were identified, however those with NC were more likely than those without NC to experience low self-efficacy, depression and severe pain which may impair the ability to self-management. Conclusions: Health care professionals have the opportunity to improve chronic pain outcomes by providing self-management advice, referring to self-management interventions, and addressing self-management barriers and facilitators. Individuals with NC may require additional health services to address their greater self-management challenges, and further research is needed to identify non-pharmaceutical interventions effective in relieving chronic pain with NC. Public policy is needed to facilitate health systems in providing long-term self-management support for individuals with chronic pain.