88 research outputs found

    Ultra-broad band perfect absorption realized by phonon-photon resonance in periodic polar dielectric material based pyramid structure

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    In this research, a mid-infrared wide-angle ultra-broadband perfect absorber which composed of pyramid grating structure has been comprehensively studied. The structure was operated in the reststrahlem band of SiC and with the presence of surface phonon resonance(SPhR), the perfect absorption was observed in the region between 10.25 and 10.85 ΞΌm\mu m. We explain the mechanism of this structure with the help of PLC circuit model due to the independence of magnetic polaritons. More over, by studying the resonance behavior of different wavelength, we bridged the continuous perfect absorption band and the discret peak in 11.05 ΞΌm\mu m(emerge two close absorption band together) by modification of the geometry. The absorption band has been sufficiently broadened. More over, both 1-D and 2-D periodic structure has been considered and the response of different incident angles and polarized angles have been studied and a omnidirectional and polarization insensitive structure can be realized which may be a candidate of several sensor applications in meteorology. The simulation was conducted by the Rigorous Coupled Wave Method(RCWA)

    Symmetry TFTs for Non-Invertible Defects

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    Given any symmetry acting on a dd-dimensional quantum field theory, there is an associated (d+1)(d+1)-dimensional topological field theory known as the Symmetry TFT (SymTFT). The SymTFT is useful for decoupling the universal quantities of quantum field theories, such as their generalized global symmetries and 't Hooft anomalies, from their dynamics. In this work, we explore the SymTFT for theories with Kramers-Wannier-like duality symmetry in both (1+1)(1+1)d and (3+1)(3+1)d quantum field theories. After constructing the SymTFT, we use it to reproduce the non-invertible fusion rules of duality defects, and along the way we generalize the concept of duality defects to \textit{higher} duality defects. We also apply the SymTFT to the problem of distinguishing intrinsically versus non-intrinsically non-invertible duality defects in (1+1)(1+1)d.Comment: 119 pages, 46 figures; v2: references added, typos corrected; v3: publication versio

    School-age population and educational planning in China

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    This study has projected, compared and analysed the trends in size of the total population, school-going population (aged 6-14) and level of school enrollment under various fertility assumptions for China during the period 1982-2012, as well as associated demands. The focus of this study is on the future school enrollment and its implications. Based on population projections by residence (rural and urban), under different mortality and fertility assumptions, this study has found that in general the size of the projected school-age population aged 6-14 and school enrollment for primary and junior high school show a falling trend broken by a substantial period of increase during the period 1982-2012, but the dimension of changes is varied under different fertility variants. With the passage of time, the differences among the projected results under different fertility variants become larger as a result of the intensified influence of fertility assumptions. Taking the projection results under the medium variant as an example, it is found that the school-going population decreases by 23 per cent during the period 1982-1992 for rural areas and by 32 per cent during the period 1982-1999 for urban areas; and increases by 35 per cent during 1992-2005 for rural areas and increase by less than 0.01 during the period 1999-2001 for urban areas; then decreases again starting from 2006 and 2002 to the end of the projection period for rural and urban areas respectively. It is further assumed that the enrollment rate will increase from 87.6 per cent in 1982 to about 99.8 per cent in 2002 for urban areas and from 73.1 per cent in 1982 to about 99.5 per cent in 2012 for rural areas, indicating the realization of a universal period of nine years of compulsory education. Correspondingly, a similar fluctuation occurs to the associated demands for teachers and funds. This study has also examined and evaluated some of the implications of the fluctuation of the projected trends of school-going population. Although the policy of population growth control will benefit the people's well-being and the national development, including the development of education, this kind of fluctuation in the population trends that will result from the implementation of the inconsistent population policy in the past must be taken into serious consideration by the policy-makers and education-planners. Flexible and appropriate strategies should be implemented in advance, for such aspects as the training of qualified teaching staff and available funds, in order to accommodate the future fluctuations in the demand for educational services

    Transcriptome And Expression Profiling Analysis Link Patterns Of Gene Expression To Antennal Responses In Spodoptera Litura

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    Background: The study of olfaction is key to understanding the interaction of insects with their environment and provides opportunities to develop novel tactics for control of pest species. Recent developments in transcriptomic approaches enable the molecular basis of olfaction to be studied even in species with limited genomic information. Here we use transcriptome and expression profiling analysis to characterize the antennal transcriptome of the noctuid moth and polyphagous pest Spodoptera litura. Results: We identify 74 candidate genes involved in odor detection and recognition, encoding 26 ORs, 21 OBPs, 18 CSPs and 9 IRs. We examine their expression levels in both sexes and seek evidence for their function by relating their expression with levels of EAG response in male and female antennae to 58 host and non-host plant volatiles and sex pheromone components. The majority of olfactory genes showed sex-biased expression, usually male-biased in ORs. A link between OR gene expression and antennal responses to odors was evident, a third of the compounds tested evoking a sex-biased response, in every case also male-biased. Two candidate pheromone receptors, OR14 and OR23 were especially strongly expressed and male-biased and we suggest that these may respond to the two female sex pheromone components of S. litura, Z9E11-14:OAc and Z9E12-14:OAc, which evoked strongly male-biased EAG responses. Conclusions: Our results provide the molecular basis for elucidating the olfactory profile of moths and the sexual divergence of their behavior and could enable the targeting of particular genes, and behaviors for pest management

    Association of vitamin D with HIV infected individuals, TB infected individuals, and HIV-TB co-infected individuals: a systematic review and meta-analysis

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    BackgroundVitamin D deficiency (VDD) is a worldwide disease. VDD is also associated with an increased risk of HIV-related comorbidities and mortality, and patients have a tendency to develop active tuberculosis compared to those with latent tuberculosis infection. Vitamin D supplementation may modulate HIV replication, improve TB inflammation and reduce progression of HIV-TB co-infection.MethodsWe meta-analyzed individual participant data from cohort studies, cross-sectional study, and RCTs of vitamin D in HIV group, TB group, and HIV-TB group. The primary outcomes were differences in vitamin D level and VDD prevalence between three groups, the secondary outcomes were CD4 count, HIV viral load, time to sputum smear conversion, time to culture conversion, relapse, morality, and TB score.ResultsFor vitamin D levels, the overall mean difference (MD) between HIV group and TB group was βˆ’0.21 (95% CI, βˆ’20.80–20.38; p = 0.9, I2 = 84%), HIV group and HIV-TB group was 0.87 (95% CI, βˆ’11.45–13.20; p = 0.89, I2 = 87%), and TB group and HIV-TB group was 1.17 (95% CI, βˆ’5.21–7.55; p = 0.72, I2 = 85%). For vitamin D deficiency prevalence, the overall odds ratio (OR) for HIV group versus TB group was 1.23 (95% CI, 0.46–3.31; p = 0.68; I2 = 70%), HIV group versus HIV-TB group was 1.53 (95% CI, 1.03–2.29; p = 0.04; I2 = 0%), and TB group versus HIV-TB group was 0.85 (95% CI, 0.61–1.20; p = 0.36; I2 = 22%). In HIV-TB group, the overall OR for vitamin D group versus placebo group was 0.78 (95% CI, 0.34–1.67; p = 0.52; I2 = 60%).ConclusionOur findings indicated that there were no variations in vitamin D levels between three groups. The prevalence of vitamin D deficiency was higher in the HIV-TB group than in the HIV group. Additionally, the administration of vitamin D supplements did not have obvious impact on CD4 count and viral load. Likewise, vitamin D had no effect on time to sputum smear conversion, time to culture conversion, relapse, 12-month morality, and TB score

    An Optimization Control Method of IEH Considering User Thermal Comfort

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    In this paper, a user thermal comfort criterion based on predicted mean vote (PMV) values is introduced to realize the optimal operation of an improved energy hub (IEH) while considering thermal inertia and user thermal behavior. A three-layer optimization model based on user thermal comfort is constructed which fully considers user thermal comfort demand, IEH operating costs, and energy network constraints. Moreover, since IEH optimization considering user thermal comfort is a multi-objective bilevel optimization (MNBO) problem, this paper proposes an improved multilayer nested quantum genetic algorithm (IMNQGA) to solve it. Finally, the effectiveness of the proposed optimization model and algorithm is verified through the analysis of the four modes. The examples show that the proposed optimal control method can reduce the system’s operating costs and improve energy efficiency while satisfying user thermal comfort demand

    Multi-scale perimeter control approach in a connected-vehicle environment

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    This paper proposes a novel approach to integrate optimal control of perimeter intersections (i.e. to minimize local delay) into the perimeter control scheme (i.e. to optimize traffic performance at the network level). This is a complex control problem rarely explored in the literature. In particular, modeling the interaction between the network level control and the local level control has not been fully considered. Utilizing the Macroscopic Fundamental Diagram (MFD) as the traffic performance indicator, we formulate a dynamic system model, and design a Model Predictive Control (MPC) based controller coupling two competing control objectives and optimizing the performance at the local and the network level as a whole. To solve this highly non-linear optimization problem, we employ an approximation framework, enabling the optimal solution of this large-scale problem to be feasible and efficient. Numerical analysis shows that by applying the proposed controller, the protected network can operate around the desired state as expressed by the MFD, while the total delay at the perimeter is minimized as well. Moreover, the paper sheds light on the robustness of the proposed controller. This multi-scale hybrid controller is further extended to a stochastic MPC scheme, where connected vehicles (CV) serve as the only data source. Hence, low penetration rates of CVs lead to strong noises in the controller. This is a first attempt to develop a network-level traffic control methodology by using the emerging CV technology. We consider the stochasticity in traffic state estimation and the shape of the MFD. Simulation analysis demonstrates the robustness of the proposed stochastic controller, showing that efficient controllers can indeed be designed with this newly-spread vehicle technology even in the absence of other data collection schemes (e.g. loop detectors).ISSN:2352-146

    Non-Invertible Symmetries of N=4\mathcal{N}=4 SYM and Twisted Compactification

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    Non-invertible symmetries have recently been understood to provide interesting contraints on RG flows of QFTs. In this work, we show how non-invertible symmetries can also be used to generate entirely new RG flows, by means of so-called "non-invertible twisted compactification". We illustrate the idea in the example of twisted compactifications of 4d N=4\mathcal{N}=4 super-Yang-Mills (SYM) to three dimensions. After giving a catalogue of non-invertible symmetries descending from Montonen-Olive duality transformations of 4d N=4\mathcal{N}=4 SYM, we show that twisted compactification by non-invertible symmetries can be used to obtain 3d N=6\mathcal{N}=6 theories which appear otherwise unreachable if one restricts to twists by invertible symmetries.Comment: 53 pages, 12 figures, 18 table

    Multi-scale perimeter control approach in a connected-vehicle environment

    No full text
    This paper proposes a novel approach to integrate optimal control of perimeter intersections (i.e. to minimize local delay) into the perimeter control scheme (i.e. to optimize traffic performance at the network level). This is a complex control problem rarely explored in the literature. In particular, modeling the interaction between the network level control and the local level control has not been fully considered. Utilizing the Macroscopic Fundamental Diagram (MFD) as the traffic performance indicator, we formulate a dynamic system model, and design a Model Predictive Control (MPC) based controller coupling two competing control objectives and optimizing the performance at the local and the network level as a whole. To solve this highly non-linear optimization problem, we employ an approximation framework, enabling the optimal solution of this large-scale problem to be feasible and efficient. Numerical analysis shows that by applying the proposed controller, the protected network can operate around the desired state as expressed by the MFD, while the total delay at the perimeter is minimized as well. Moreover, the paper sheds light on the robustness of the proposed controller. This multi-scale hybrid controller is further extended to a stochastic MPC scheme, where connected vehicles (CV) serve as the only data source. Hence, low penetration rates of CVs lead to strong noises in the controller. This is a first attempt to develop a network-level traffic control methodology by using the emerging CV technology. We consider the stochasticity in traffic state estimation and the shape of the MFD. Simulation analysis demonstrates the robustness of the proposed stochastic controller, showing that efficient controllers can indeed be designed with this newly-spread vehicle technology even in the absence of other data collection schemes (e.g. loop detectors).ISSN:2352-146
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