Nanchang Hangkong University

About: Nanchang Hangkong University is a education organization based out in Nanchang, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 7004 authors who have published 5270 publications receiving 62162 citations. The organization is also known as: Nanchang Aviation University.

Metal‐Free Annulation Cascades of 1,7‐Enynes Using Di‐tert‐butyl Peroxide as the Methyl Source towards the Synthesis of Polyheterocyclic Scaffolds

Abstract: A new metal-free oxidative cascade methylation/cyclization of benzene-linked 1,7-enynes is described for the construction of methylated polyheterocyclic scaffolds skeletons. In this transformations, three new C-C bonds and two new rings were formed. Notably, di-tert-butyl peroxide (DTBP) acts not only a radical initiator but also an efficient methyl source.

Online Low-Rank Representation Learning for Joint Multi-Subspace Recovery and Clustering

Abstract: Benefiting from global rank constraints, the low-rank representation (LRR) method has been shown to be an effective solution to subspace learning. However, the global mechanism also means that the LRR model is not suitable for handling large-scale data or dynamic data. For large-scale data, the LRR method suffers from high time complexity, and for dynamic data, it has to recompute a complex rank minimization for the entire data set whenever new samples are dynamically added, making it prohibitively expensive. Existing attempts to online LRR either take a stochastic approach or build the representation purely based on a small sample set and treat new input as out-of-sample data. The former often requires multiple runs for good performance and thus takes longer time to run, and the latter formulates online LRR as an out-of-sample classification problem and is less robust to noise. In this paper, a novel online LRR subspace learning method is proposed for both large-scale and dynamic data. The proposed algorithm is composed of two stages: static learning and dynamic updating. In the first stage, the subspace structure is learned from a small number of data samples. In the second stage, the intrinsic principal components of the entire data set are computed incrementally by utilizing the learned subspace structure, and the LRR matrix can also be incrementally solved by an efficient online singular value decomposition algorithm. The time complexity is reduced dramatically for large-scale data, and repeated computation is avoided for dynamic problems. We further perform theoretical analysis comparing the proposed online algorithm with the batch LRR method. Finally, experimental results on typical tasks of subspace recovery and subspace clustering show that the proposed algorithm performs comparably or better than batch methods, including the batch LRR, and significantly outperforms state-of-the-art online methods.

Sensing atmospheric reactive species using light emitting diode by incoherent broadband cavity enhanced absorption spectroscopy

Abstract: We overview our recent progress in the developments and applications of light emitting diode-based incoherent broadband cavity enhanced absorption spectroscopy (LED-IBBCEAS) techniques for real-time optical sensing chemically reactive atmospheric species (HONO, NO3, NO2) in intensive campaigns and in atmospheric simulation chamber. New application of optical monitoring of NO3 concentration-time profile for study of the NO3-initiated oxidation process of isoprene in a smog chamber is reported.

Highly efficient and stable hydrogen evolution from water with CdS as photosensitizer-A noble-metal-free system

Abstract: a b s t r a c t CdS/Ba1−xZnxTiO3 heterostructured photocatalysts were developed as a highly efficient and stable system for photocatalytic evolution of hydrogen from water splitting. In the system, CdS not only functions as photosensitizer to absorb visible light, but also participates with Ba1−xZnxTiO3 for the generation of heterojunctions that block the recombination of photogenerated electrons and holes. The photocatalysts show excellent activity and stability, giving a high H2 production rate of 1473 mol h−1 g−1 under the irradiation of simulated solar light in a test period of 480 h without loading any noble metal as cocatalyst or any reagents for regeneration. This study demonstrates that the development of CdS nanoparticles as photosensitizer is feasible for the photocatalytic H2 production.