66 research outputs found

    High-quality multi-wavelength quantum light sources on silicon nitride micro-ring chip

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    Multi-wavelength quantum light sources, especially at telecom band, are extremely desired in quantum information technology. Despite recent impressive advances, such a quantum light source with high quality remains challenging. Here we demonstrate a multi-wavelength quantum light source using a silicon nitride micro-ring with a free spectral range of 200 GHz. The generation of eight pairs of correlated photons is ensured in a wavelength range of 25.6 nm. With device optimization and noise-rejecting filters, our source enables the generation of heralded single-photons - at a rate of 62 kHz with gh(2)(0)=0.014±0.001g^{(2)}_{h}(0)=0.014\pm0.001, and the generation of energy-time entangled photons - with a visibility of 99.39±0.45%99.39\pm 0.45\% in the Franson interferometer. These results, at room temperature and telecom wavelength, in a CMOS compatible platform, represent an important step towards integrated quantum light devices for the quantum networks.Comment: 7 pages, 4 figure

    RNA-Seq based phylogeny recapitulates previous phylogeny of the genus Flaveria (Asteraceae) with some modifications

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    Abstract Background The genus Flaveria has been extensively used as a model to study the evolution of C4 photosynthesis as it contains C3 and C4 species as well as a number of species that exhibit intermediate types of photosynthesis. The current phylogenetic tree of the genus Flaveria contains 21 of the 23 known Flaveria species and has been previously constructed using a combination of morphological data and three non-coding DNA sequences (nuclear encoded ETS, ITS and chloroplast encoded trnL-F). Results Here we developed a new strategy to update the phylogenetic tree of 16 Flaveria species based on RNA-Seq data. The updated phylogeny is largely congruent with the previously published tree but with some modifications. We propose that the data collection method provided in this study can be used as a generic method for phylogenetic tree reconstruction if the target species has no genomic information. We also showed that a “F. pringlei” genotype recently used in a number of labs may be a hybrid between F. pringlei (C3) and F. angustifolia (C3-C4). Conclusions We propose that the new strategy of obtaining phylogenetic sequences outlined in this study can be used to construct robust trees in a larger number of taxa. The updated Flaveria phylogenetic tree also supports a hypothesis of stepwise and parallel evolution of C4 photosynthesis in the Flavaria clade

    RNA-Seq based phylogeny recapitulates previous phylogeny of the genus Flaveria (Asteraceae) with some modifications.

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    BACKGROUND: The genus Flaveria has been extensively used as a model to study the evolution of C4 photosynthesis as it contains C3 and C4 species as well as a number of species that exhibit intermediate types of photosynthesis. The current phylogenetic tree of the genus Flaveria contains 21 of the 23 known Flaveria species and has been previously constructed using a combination of morphological data and three non-coding DNA sequences (nuclear encoded ETS, ITS and chloroplast encoded trnL-F). RESULTS: Here we developed a new strategy to update the phylogenetic tree of 16 Flaveria species based on RNA-Seq data. The updated phylogeny is largely congruent with the previously published tree but with some modifications. We propose that the data collection method provided in this study can be used as a generic method for phylogenetic tree reconstruction if the target species has no genomic information. We also showed that a "F. pringlei" genotype recently used in a number of labs may be a hybrid between F. pringlei (C3) and F. angustifolia (C3-C4). CONCLUSIONS: We propose that the new strategy of obtaining phylogenetic sequences outlined in this study can be used to construct robust trees in a larger number of taxa. The updated Flaveria phylogenetic tree also supports a hypothesis of stepwise and parallel evolution of C4 photosynthesis in the Flavaria clade

    Boundary vibration control of a floating wind turbine system with mooring lines

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    In this paper, we investigate dynamic modeling, active boundary control design, and stability analysis for a coupled floating wind turbine (FWT) system, which is connected with two flexible mooring lines. It is a coupled beam-strings structure, and we design two boundary controllers to restrain the vibrations of this flexible system caused by external disturbances based on the coupled partial differential equations and ordinary differential equations (PDEs–ODEs) model. Meanwhile, significant performance of designed boundary controllers and system’s stability are theoretically analyzed, and a set of simulation results are provided to show efficacy of the proposed approach

    Hemostasis effect and mechanism of Triamcinolone acetonide in the treatment of PDR

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    AIM: To analyze the hemostatic effect and mechanism of triamcinolone acetonide in the treatment of proliferative diabetic retinopathy(PDR).METHODS: Totally 400 patients were treated in our hospital for PDR between January 2013 and March 2014. All subjects were divided into groups. The control group was treated with vitrectomy directly. The observation group was treated with triamcinolone acetonide at 4-14d before surgery. The differences of the indexes and complications in postoperative vision correction were compared between the two groups.RESULTS: The expression levels of u-PA, t-PA and PAI-1 in the observation group were significantly higher than those in the control group(PPPPCONCLUSION: Vitrectomy in patients with PDR is often accompanied by hemorrhage and various complications. The use of triamcinolone acetonide can regulate the level of multiple clotting factors in the vitreous cavity of the patient, thereby reducing the amount of bleeding or directly exerting hemostasis, increasing surgical safety, reducing the incidence of complications, which is worthy of clinical application

    Tensor Graphical Model: Non-Convex Optimization and Statistical Inference

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    We consider the estimation and inference of graphical models that characterize the dependency structure of high-dimensional tensor-valued data. To facilitate the estimation of the precision matrix corresponding to each way of the tensor, we assume the data follow a tensor normal distribution whose covariance has a Kronecker product structure. A critical challenge in the estimation and inference of this model is the fact that its penalized maximum likelihood estimation involves minimizing a non-convex objective function. To address it, this paper makes two contributions: (i) In spite of the non-convexity of this estimation problem, we prove that an alternating minimization algorithm, which iteratively estimates each sparse precision matrix while fixing the others, attains an estimator with an optimal statistical rate of convergence. (ii) We propose a de-biased statistical inference procedure for testing hypotheses on the true support of the sparse precision matrices, and employ it for testing a growing number of hypothesis with false discovery rate (FDR) control. The asymptotic normality of our test statistic and the consistency of FDR control procedure are established. Our theoretical results are backed up by thorough numerical studies and our real applications on neuroimaging studies of Autism spectrum disorder and users' advertising click analysis bring new scientific findings and business insights. The proposed methods are encoded into a publicly available R package Tlasso

    Pseudo-Signal Interference Regularity of Single-Frequency Electromagnetic Radiation to Stepped-Frequency Radar

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    When typical radar equipment is subjected to single-frequency electromagnetic radiation, the radar display interface forms a pseudo-signal, resulting in the misjudgment of real targets. Based on the working principle of stepped-frequency radar ranging, the effect mechanism of radar equipment pseudo-signal interference is revealed. Taking a Ku band stepped-frequency ranging radar as the test object, the pseudo-signal interference effect test of single-frequency electromagnetic radiation is carried out in this study. The pseudo-signal level value of 6 dBmV is selected as the sensitive criterion of the pseudo-signal interference effect. Through experiments, the variation curves of the pseudo-signal level values of the sensitive frequency bands and the typical frequency points inside and outside the band with the field strength of the single-frequency interference are obtained. Based on the nonlinear distortion analysis of the receiving circuit, the variation laws of the pseudo-signal level values inside and outside the band are explained, respectively. The experimental results show that there are at least seven pseudo-signal interference-sensitive bands in the tested radar, and the first pseudo-signal strength is only related to the interference signal strength. The essence of the second type of pseudo-signal interference is intermodulation interference, and the pseudo-signal level is related to the interference signal and the useful signal strength

    Antidepressant Effects of Electroconvulsive Therapy Unrelated to the Brain's Functional Network Connectivity alterations at an Individual Level

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    Background: Electroconvulsive therapy (ECT) can alleviate the symptoms of treatment-resistant depression (TRD). Functional network connectivity (FNC) is a newly developed method to investigate the brain's functional connectivity patterns. The first aim of this study was to investigate FNC alterations between TRD patients and healthy controls. The second aim was to explore the relationship between the ECT treatment response and pre-ECT treatment FNC alterations in individual TRD patients. Methods: This study included 82 TRD patients and 41 controls. Patients were screened at baseline and after 2 weeks of treatment with a combination of ECT and antidepressants. Group information guided-independent component analysis (GIG-ICA) was used to compute subject-specific functional networks (FNs). Grassmann manifold and step-wise forward component selection using support vector machines were adopted to perform the FNC measure and extract the functional networks' connectivity patterns (FCP). Pearson's correlation analysis was used to calculate the correlations between the FCP and ECT response. Results: A total of 82 TRD patients in the ECT group were successfully treated. On an average, 8.50 ± 2.00 ECT sessions were conducted. After ECT treatment, only 42 TRD patients had an improved response to ECT (the Hamilton scores reduction rate was more than 50%), response rate 51%. 8 FNs (anterior and posterior default mode network, bilateral frontoparietal network, audio network, visual network, dorsal attention network, and sensorimotor network) were obtained using GIG-ICA. We did not found that FCPs were significantly different between TRD patients and healthy controls. Moreover, the baseline FCP was unrelated to the ECT treatment response. Conclusions: The FNC was not significantly different between the TRD patients and healthy controls, and the baseline FCP was unrelated to the ECT treatment response. These findings will necessitate that we modify the experimental scheme to explore the mechanisms underlying ECT's effects on depression and explore the specific predictors of the effects of ECT based on the pre-ECT treatment magnetic resonance imaging

    Quantitative evaluation method of fault lateral sealing

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    The fault-reservoir displacement pressure differential method, as a quantitative evaluation method of fault sealing which considering diagenetic time of fault rock, was improved based on the study of fault sealing mechanism and its influencing factors. A geology and mathematical model of quantitative evaluation of fault sealing considering diagenetic time was established. First, the depth of surrounding rock which has the same shale content and diagenetic degree as the fault rocks at the target was determined using the method of successive approximation at the given step length. Second, the displacement pressure of target fault rocks was calculated based on the relationship between the displacement pressure and the product of shale content and burial depth that was established for the study area. And third, the sealing states and capacity of the faults were quantitatively evaluated by comparing the calculated displacement pressure with that of the target reservoir. By the actual data of reservoirs at Banqiao Fault in Qikou sag and the result comparison between fault rock shale content method (SGR) and fault-reservoir displacement pressure differential method without considering the diagenetic time, it is verified that this method is more feasible and credible. Key words: Qikou Sag, fault rock, lateral sealing ability, sealing ability quantitative evaluation, displacement pressur
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