149 research outputs found
Single-shot compressed ultrafast photography: a review
Compressed ultrafast photography (CUP) is a burgeoning single-shot computational imaging technique that provides an imaging speed as high as 10 trillion frames per second and a sequence depth of up to a few hundred frames. This technique synergizes compressed sensing and the streak camera technique to capture nonrepeatable ultrafast transient events with a single shot. With recent unprecedented technical developments and extensions of this methodology, it has been widely used in ultrafast optical imaging and metrology, ultrafast electron diffraction and microscopy, and information security protection. We review the basic principles of CUP, its recent advances in data acquisition and image reconstruction, its fusions with other modalities, and its unique applications in multiple research fields
Technical Debt Management in OSS Projects: An Empirical Study on GitHub
Technical debt (TD) refers to delayed tasks and immature artifacts that may
bring short-term benefits but incur extra costs of change during maintenance
and evolution in the long term. TD has been extensively studied in the past
decade, and numerous open source software (OSS) projects were used to explore
specific aspects of TD and validate various approaches for TD management (TDM).
However, there still lacks a comprehensive understanding on the practice of TDM
in OSS development, which penetrates the OSS community's perception of the TD
concept and how TD is managed in OSS development. To this end, we conducted an
empirical study on the whole GitHub to explore the adoption and execution of
TDM based on issues in OSS projects. We collected 35,278 issues labeled as TD
(TD issues) distributed over 3,598 repositories in total from the issue
tracking system of GitHub between 2009 and 2020. The findings are that: (1) the
OSS community is embracing the TD concept; (2) the analysis of TD instances
shows that TD may affect both internal and external quality of software
systems; (3) only one TD issue was identified in 31.1% of the repositories and
all TD issues were identified by only one developer in 69.0% of the
repositories; (4) TDM was ignored in 27.3% of the repositories after TD issues
were identified; and (5) among the repositories with TD labels, 32.9% have
abandoned TDM while only 8.2% adopt TDM as a consistent practice. These
findings provide valuable insights for practitioners in TDM and promising
research directions for further investigation.Comment: 15 pages, 8 images, 10 tables, Manuscript submitted to a Journal
(2022
Canopy Spectral Characterization of Wheat Stripe Rust in Latent Period
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the important wheat diseases worldwide. In this study, the spectral data were collected from wheat canopy during the latent period inoculated with three different concentrations of urediniospores and classification models based on discriminant partial least squares (DPLS) were built to differentiate leaves with and without infection of the stripe rust pathogen. The effects of different spectra features, wavebands, and the number of the samples used in modeling on the performances of the models were assessed. The results showed that, in the spectral region of 325-1075 nm, the model with the spectral feature of 2nd derivative of Pseudoabsorption index had better accuracy than others. The average accuracy rate was 97.28% for the training set and 92.98% for the testing set. In the waveband of 925-1075 nm, the model with the spectral feature of 1st derivative Pseudoabsorption index had better accuracy than other models, and the average accuracy rates were 98.27% and 94.33% for the training and testing sets, respectively. The results demonstrated that wheat stripe rust in latent period can be qualitatively identified based on the canopy spectral detection. Thus, the method can be used for early monitoring of infections of wheat stripe rust
荧光可视化探针检测胆红素
The content of bilirubin is an important index to evaluate human health. A special nanocomposite was designed and constructed in this project. The content of bilirubin was detected by the change of fluorescence ratio signal generated when it was combined with bilirubin. Finally, the test paper is prepared to realize the convenient detection of bilirubin
Single-shot compressed ultrafast photography: a review
Compressed ultrafast photography (CUP) is a burgeoning single-shot computational imaging technique that provides an imaging speed as high as 10 trillion frames per second and a sequence depth of up to a few hundred frames. This technique synergizes compressed sensing and the streak camera technique to capture nonrepeatable ultrafast transient events with a single shot. With recent unprecedented technical developments and extensions of this methodology, it has been widely used in ultrafast optical imaging and metrology, ultrafast electron diffraction and microscopy, and information security protection. We review the basic principles of CUP, its recent advances in data acquisition and image reconstruction, its fusions with other modalities, and its unique applications in multiple research fields
Efficacy mechanisms research progress of the active components in the characteristic woody edible oils
Woody edible oils are a type of vegetable oil. Woody edible oils like olive oil have greater quantities of unsaturated fatty acids (UFAs), particularly essential FAs, as well as vitamin E, phytosterols, and other nutrients that are becoming more vital in human health. As a result, finding high-quality woody oil resource plants is critical to ensuring enough edible oil supply. As six novel woody crops, Paeonia suffruticosa, Plukenetia volubilis, Acer truncatum, Olea europaea, Camellia sinensis, and Camellia oleifera are characterized by high oil production, widespread cultivation, adaptability, and various active ingredients. The six woody crop oils contain UFAs (e.g., α-linolenic acid, oleic acid, and linoleic acid), vitamin E, polyphenols, phytosterols, and so forth. The presence of these active ingredients confers anti-inflammatory, antioxidant, cholesterol and lipid metabolism regulating, blood lipid lowering, immune boosting, memory improving, intestinal flora regulating, and other properties to the oils, which are beneficial to body health. This article examined in depth the seed resources, FA composition, active component kinds, active ingredient efficacy mechanism, and physiological impacts of these six novel woody crop oils. These developments lay a solid platform for further study and development of these woody oil crops.This work was supported by the Key Research and Development Program of Zhejiang Province (No. 2021C02002), Zhejiang Provincial Natural Sciences Foundation of China under Grant (No. LZ22C200006), Top young talents of the ten thousand talents program of Zhejiang Province (ZJWR0308016), Key R&D projects in Zhejiang Province (2023C04010), and Zhejiang Basic Public Welfare Research Project (LGN21C200006). Agusti Romero acknowledges financial support from the CERCA Program from the Generalitat of Catalonia. We would like to thank all contributors of the current study for their concepts, ideas, contribution, and provision.info:eu-repo/semantics/publishedVersio
Landau Quantization of Massless Dirac Fermions in Topological Insulator
The recent theoretical prediction and experimental realization of topological
insulators (TI) has generated intense interest in this new state of quantum
matter. The surface states of a three-dimensional (3D) TI such as Bi_2Te_3,
Bi_2Se_3 and Sb_2Te_3 consist of a single massless Dirac cones. Crossing of the
two surface state branches with opposite spins in the materials is fully
protected by the time reversal (TR) symmetry at the Dirac points, which cannot
be destroyed by any TR invariant perturbation. Recent advances in thin-film
growth have permitted this unique two-dimensional electron system (2DES) to be
probed by scanning tunneling microscopy (STM) and spectroscopy (STS). The
intriguing TR symmetry protected topological states were revealed in STM
experiments where the backscattering induced by non-magnetic impurities was
forbidden. Here we report the Landau quantization of the topological surface
states in Bi_2Se_3 in magnetic field by using STM/STS. The direct observation
of the discrete Landau levels (LLs) strongly supports the 2D nature of the
topological states and gives direct proof of the nondegenerate structure of LLs
in TI. We demonstrate the linear dispersion of the massless Dirac fermions by
the square-root dependence of LLs on magnetic field. The formation of LLs
implies the high mobility of the 2DES, which has been predicted to lead to
topological magneto-electric effect of the TI.Comment: 15 pages, 4 figure
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