Nanjing University of Science and Technology

About: Nanjing University of Science and Technology is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 31581 authors who have published 36390 publications receiving 525474 citations. The organization is also known as: Nánjīng Lǐgōng Dàxué & Nánlǐgōng.

Application of the fractional Fourier transform to moving target detection in airborne SAR

Abstract: As a useful signal processing technique, the fractional Fourier transform (FrFT) is largely unknown to the radar signal processing community. In this correspondence, the FrFT is applied to airborne synthetic aperture radar (SAR) slow-moving target detection. For airborne SAR, the echo from a ground moving target can be regarded approximately as a chirp signal, and the FrFT is a way to concentrate the energy of a chirp signal. Therefore, the FrFT presents a potentially effective technique for ground moving target detection in airborne SAR. Compared with the common Wigner-Ville distribution (WVD) algorithm, the FrFT is a linear operator, and will not be influenced by cross-terms even if multiple moving targets exist. Moreover, to solve the problem whereby weak targets are shadowed by the sidelobes of strong ones, a new implementation of the CLEAN technique is proposed based on filtering in the fractional Fourier domain. In this way strong moving targets and weak ones can be detected iteratively. This combined method is demonstrated by using raw clutter data combined with simulated moving targets.

Buckling analysis of FG-CNT reinforced composite thick skew plates using an element-free approach

Abstract: The buckling behavior of functionally graded carbon nanotube (FG-CNT) reinforced composite thick skew plates is studied. The CNTs are reinforced uniaxially aligned in the axial direction. Material properties of the nanocomposites are assumed to be graded in the thickness direction. The element-free IMLS-Ritz method is employed for the numerical analysis. The theoretical formulation has incorporated the effects of transverse shear deformation and rotary inertia through employing the first-order shear deformation theory (FSDT). A few numerical examples are chosen to demonstrate the numerical stability and accuracy of the IMLS-Ritz method. The validity of the IMLS-Ritz results is examined by comparing them with those of the known data in the literature. Parametric studies are conducted for various types of CNTs distributions, CNT ratios, skew plates, aspect ratios and thickness-to-height ratios under different boundary conditions. Some conclusions are drawn on the parametric studies with respect to the buckling characteristics.

Graphene/SnO2/polypyrrole ternary nanocomposites as supercapacitor electrode materials

Abstract: A ternary electrode material, based on graphene, tin oxide (SnO2) and polypyrrole (PPy) was obtained via one–pot synthesis. The graphene/SnO2/PPy (GSP) nanocomposite is composed of a thin conducting film of PPy on the surface of graphene/SnO2 (GS). An enhanced specific capacitance (616 F g−1) of GSP was obtained at 1 mV s−1 in 1 M H2SO4 compared with GS (80.2 F g−1) and PPy (523 F g−1). The GSP electrode shows better cycle stability and no obvious decay after 1000 galvanostatic cycles at 1 A g−1. Its specific power density and energy density can reach 9973.26 W kg−1, and 19.4 W h kg−1, respectively. The excellent electrochemical performance arises from the well-designed structure advantages, the good combination of components and the synergistic effect between the three components. Well-dispersed graphene is used as a framework for sustaining the pseudocapacitive materials of SnO2 and PPy. The PPy film restricts the aggregation and volume change of SnO2 during charge–discharge cycling, and also enhances the surface area. The electrochemical results show that the ternary composite of GSP is a promising candidate electrode material for high-performance supercapacitors.

Evaluation and Discovery of Novel Synthetic Chalcone Derivatives as Anti-Inflammatory Agents

Abstract: Major anti-inflammatory agents, steroids and cyclooxygenase, were proved to have serious side effects. Here, a series of chalcone derivatives were synthesized and screened for anti-inflammatory activities. QSAR study revealed that the presence of electron-withdrawing groups in B-ring and electron-donating groups in A-ring of chalcones was important for inhibition of LPS-induced IL-6 expression. Further, compounds 22, 23, 26, 40, and 47 inhibited TNF-α and IL-6 release in a dose-dependent manner and decreased LPS-induced TNF-α, IL-1β, IL-6, IL-12, and COX-2 mRNA production. Mechanistically, compounds 23 and 26 interfered with JNK/NF-κB signaling and dose-dependently prevented ERK and p38 activation. In addition, 23 and 26 exhibited a significant protection against LPS-induced death and were able to block high glucose-activated cytokine profiles in macrophages. Together, these data show a series of anti-inflammatory chalcones with potential therapeutic effects in inflammatory diseases.

A universal layer-by-layer solution-processing approach for efficient non-fullerene organic solar cells

Abstract: Layer-by-layer (LbL) solution processing is a cost-effective technology for the large-scale fabrication of organic solar cells (OSCs). In this work, LbL OSCs were fabricated using PTQ10/J71 as donors and ITC6-IC/IDIC/MeIC/ITCPTC/ITIC as non-fullerene acceptors (NFAs) without using orthogonal solvents and appropriate co-solvents. Compared with traditional bulk heterojunction (BHJ) OSCs, the corresponding solution-processed LbL devices exhibited higher or comparable power conversion efficiencies (PCEs), which had the advantages of reduced energy loss, stronger absorption spectra, better vertical phase separation, partially increased charge transport property and charge collection efficiency. Furthermore, taking the J71/ITC6-IC and PTQ10/IDIC LbL systems as examples, we fabricated large-area LbL OSCs using the doctor-blading process, which is closer to the roll-to-roll (R2R) technology. Importantly, both OSCs based on J71/ITC6-IC and PTQ10/IDIC LbL with an active area of 1.00 cm2 demonstrated encouraging PCEs of over 10%, which is the record efficiency for large-area LbL OSCs reported in the literature to date. Our work indicates that the solution-processed LbL approach not only presents good generality and high device performance, but also is a superior alternative to the BHJ method for the initial evaluation of photovoltaic materials and the industrial production of R2R OSCs.