Nankai University

About: Nankai University is a education organization based out in Tianjin, China. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 42964 authors who have published 51866 publications receiving 1127896 citations. The organization is also known as: Nánkāi Dàxué.

Measurements of the cross section for e(+)e(-) --> hadrons at center-of-mass energies from 2 to 5 GeV.

Abstract: We report values of $R\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons})/\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$ for 85 center-of-mass energies between 2 and $5\mathrm{GeV}$ measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.

Improving Convolutional Networks With Self-Calibrated Convolutions

Abstract: Recent advances on CNNs are mostly devoted to designing more complex architectures to enhance their representation learning capacity. In this paper, we consider how to improve the basic convolutional feature transformation process of CNNs without tuning the model architectures. To this end, we present a novel self-calibrated convolutions that explicitly expand fields-of-view of each convolutional layers through internal communications and hence enrich the output features. In particular, unlike the standard convolutions that fuse spatial and channel-wise information using small kernels (e.g., 3x3), self-calibrated convolutions adaptively build long-range spatial and inter-channel dependencies around each spatial location through a novel self-calibration operation. Thus, it can help CNNs generate more discriminative representations by explicitly incorporating richer information. Our self-calibrated convolution design is simple and generic, and can be easily applied to augment standard convolutional layers without introducing extra parameters and complexity. Extensive experiments demonstrate that when applying self-calibrated convolutions into different backbones, our networks can significantly improve the baseline models in a variety of vision tasks, including image recognition, object detection, instance segmentation, and keypoint detection, with no need to change the network architectures. We hope this work could provide a promising way for future research in designing novel convolutional feature transformations for improving convolutional networks. Code is available on the project page.

Proton Insertion Chemistry of a Zinc–Organic Battery

Abstract: Proton storage in rechargeable aqueous zinc-ion batteries (ZIBs) is attracting extensive attention owing to the fast kinetics of H+ insertion/extraction. However, it has not been achieved in organic materials-based ZIBs with a mild electrolyte. Now, aqueous ZIBs based on diquinoxalino [2,3-a:2',3'-c] phenazine (HATN) in a mild electrolyte are developed. Electrochemical and structural analysis confirm for the first time that such Zn-HATN batteries experience a H+ uptake/removal behavior with highly reversible structural evolution of HATN. The H+ uptake/removal endows the Zn-HATN batteries with enhanced electrochemical performance. Proton insertion chemistry will broaden the horizons of aqueous Zn-organic batteries and open up new opportunities to construct high-performance ZIBs.

Au-doped WO3-based sensor for NO2 detection at low operating temperature

Abstract: Pure and Au-doped WO3 powders for NO2 gas detection were prepared by a colloidal chemical method, and characterized via X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The NO2 sensing properties of the sensors based on pure and Au-doped WO3 powders were investigated by HW-30A gas sensing measurement. The results showed that the gas sensing properties of the doped WO3 sensors were superior to those of the undoped one. Especially, the 1.0 wt% Au-doped WO3 sensor possessed larger response, better selectivity, faster response/recovery and better longer term stability to NO2 than the others at relatively low operating temperature (150 °C).

Rotation Restricted Emission and Antenna Effect in Single Metal-Organic Frameworks.

Abstract: Aggregation induced-emission (AIE) and antenna effects are important luminescence behaviors. Thus, investigating their emission mechanisms and revealing their behaviors have become critical but challenging. Here we design and prepare metal-organic frameworks (MOFs) with an AIE ligand (i.e., tetrakis(4-carboxyphenyl)pyrazine (L1)) and Ln3+ ions (including Eu3+, Tb3+, and Gd3+). The emission from L1 is gradually enhanced during the formation of the MOFs because coordination restricts the intramolecular rotation. Thus, the emission is called as coordination-induced emission (CIE) with the same restriction of intramolecular rotation mechanism as AIE. Meanwhile, benzene rings twist to adapt to the MOFs' rigid structure, so the emission blueshifts gradually, as an additional evidence of CIE. Both AIE and CIE are "rotation-restricted emission (RRE)". Eu3+ ions exhibit the strongest emission with gradually enhanced intensity during the formation of L1-Eu MOF. Combined with emission properties from Tb3+ and Gd3+ ions, the antenna effect is verified. We also validate the conditions for the efficient sensitization of Ln3+ ions experimentally and refresh the threshold value of the energy gap between triplet state of a ligand and excited state of Ln3+ ions to 3000 cm-1. Thus, RRE and antenna effects are revealed and validated simultaneously. Because CIE of L1 and antenna effect emission from Eu3+ ions are enhanced simultaneously as strong dual emissions, ratiometric fluorescence detection is realized with the detection of arginine as a model. Our results incorporate AIE and CIE into RRE, which provides explicit information for the construction and application of emission systems with AIE ligands as building blocks. MOFs are also extended to explore the emission mechanism and the energy transfer between ligands and metal ions.