Probability Weighted Compact Feature for Domain Adaptive Retrieval

Domain adaptive image retrieval includes single-domain retrieval and cross-domain retrieval. Most of the existing image retrieval methods only focus on single-domain retrieval, which assumes that the distributions of retrieval databases and queries are similar. However, in practical application, the discrepancies between retrieval databases often taken in ideal illumination/pose/background/camera conditions and queries usually obtained in uncontrolled conditions are very large. In this paper, considering the practical application, we focus on challenging cross-domain retrieval. To address the problem, we propose an effective method named Probability Weighted Compact Feature Learning (PWCF), which provides inter-domain correlation guidance to promote cross-domain retrieval accuracy and learns a series of compact binary codes to improve the retrieval speed. First, we derive our loss function through the Maximum A Posteriori Estimation (MAP): Bayesian Perspective (BP) induced focal-triplet loss, BP induced quantization loss and BP induced classification loss. Second, we propose a common manifold structure between domains to explore the potential correlation across domains. Considering the original feature representation is biased due to the inter-domain discrepancy, the manifold structure is difficult to be constructed. Therefore, we propose a new feature named Histogram Feature of Neighbors (HFON) from the sample statistics perspective. Extensive experiments on various benchmark databases validate that our method outperforms many state-of-the-art image retrieval methods for domain adaptive image retrieval. The source code is available at https://github.com/fuxianghuang1/PWCFComment: Accepted by CVPR 2020; The source code is available at https://github.com/fuxianghuang1/PWC

Nitrogen-Doped Multi-Scale Porous Carbon for High Voltage Aqueous Supercapacitors

Recently, “Water-in-salt” electrolyte has been reported to extend the working voltage of aqueous supercapacitor. However, this electrolyte needs the electrode materials possess some good features such as proper pore structure, high electron and ion conductivity. Herein, we fabricated the nitrogen-doped multi-scale porous carbon (NMC) by the simple enriching melamine-resorcinol-formaldehyde xerogels method with integrating triblock copolymer for micro-pores formation. All the results confirmed that our NMC is provided with a very high specific surface area (3,170 m2 g−1) and its monoliths are composed of multi-scale porous structure. By employing the nanostructured NMC as electrode materials, we have investigated the capability for high-voltage aqueous supercapacitor applications. The superconcentrated “Water-in-salt” electrolyte expand stability operating potential window of aqueous symmetric supercapacitor up to 2.4 V with a high energy density of 33 Wh kg−1 at power density of 0.3 kW kg−1. Our studies indicate that the NMC is potential materials for high performance over wider voltage range

Fabrication of WO3·2H2O/BC Hybrids by the Radiation Method for Enhanced Performance Supercapacitors

In this study, we described a facile process for the fabrication of tungsten oxide dihydrate/bamboo charcoal hybrids (WO3·2H2O/BC) by the γ-irradiation method. The structural, morphological, and electrochemical properties of WO3·2H2O/BC hybrids were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. The combination of BC (electrical double layer charge) and WO3·2H2O (pseudocapacitance) created a combined effect, which enhanced the specific capacitance and superior cyclic stability of the WO3·2H2O/BC hybrid electrode. The WO3·2H2O/BC hybrids showed the higher specific capacitance (391 F g−1 at 0.5 A g−1 over the voltage range from −1 to 0 V), compared with BC (108 F g−1) in 6 M KOH solution. Furthermore, the hybrid electrode showed superior long-term performance with 82% capacitance retention even after 10,000 cycles. The experimental results demonstrated that the high performance of WO3·2H2O/BC hybrids could be a potential electrode material for supercapacitors

Can aliphatic anchoring groups be utilised with dyes for p-type dye sensitized solar cells?

A series of novel laterally anchoring tetrahydroquinoline derivatives have been synthesized and investigated for their use in NiO-based p-type dye-sensitized solar cells. The kinetics of charge injection and recombination at the NiO-dye interface for these dyes have been thoroughly investigated using picosecond transient absorption and time-resolved infrared measurements. It was revealed that despite the anchoring unit being electronically decoupled from the dye structure, charge injection occurred on a sub picosecond timescale. However, rapid recombination was also observed due to the close proximity of the electron acceptor on the dyes to the NiO surface, ultimately limiting the performance of the p-DSCs

Emulsions stabilized by nanofibers from bacterial cellulose: New potential food-grade Pickering emulsions

In the present work, we investigated the formation and stability of Pickering emulsions stabilized by nanoparticles generated from bacterial cellulose (BC) by hydrochloric acid hydrolysis. The resulting particles, called nanofibers, presented a ribbonlike shape with diameters of 30–80 nm and range in length from 100 nm to several micrometers. The obtained nanofibers showed good hydrophilic and lipophilic properties and had significant ability to reduce the surface tension of oil/water droplets from 48.55 ± 0.03 to 34.52 ± 0.05 mN/m. The oil-in-water Pickering emulsions with a peanut oil concentration of 15% (v/v) were stabilized by only 0.05% (w/v) nanofibers and displayed a narrow droplet size distribution and high intensity with an average droplet size of 15.00 ± 0.82 nm. The morphological studies confirmed the nano-scaled droplets of emulsions. The effects of pH values and temperatures on the creaming ability and physical stability were also evaluated by zeta-potential and droplet sizes. Results showed that emulsions displayed relatively lower creaming ability at pH < 7, while displayed optimal physical stability and dispersibility at pH ≥ 7. The temperature (20–100 °C) and time-dependent test (0–4 weeks) indicated that the Pickering emulsions stabilized by only 0.05% (w/v) nanofibers displayed excellent stability. Due to the sustainability and good bio-compatibility of nanofibers from BC, the developed emulsions stabilized by low concentration of nanofibers can be used as new food-grade Pickering emulsions and have great potential to deliver lipophilic bioactive substances in food industry

Recent advances of theranotics agents based on copper chalcogenide

Near infrared photothermal theranostics is an emerging therapy that has great potential in cancer therapy.With this theranostics,more effective prevention,screening,and treatment strategies for individualized cancer therapy will be found.Theranostics agents for cancer based on copper chalcogenide nanomaterials have become one of the attractive research fields recently due to their strong near-infrared absorptions,higher photothermal conversion efficiencies,low cost,and easy preparation.This review introduces the recent advances related to the diagnosis,treatment,and theranostics based on the copper chalcogenide nanomaterials for cancer

A metal-free "black dye" for panchromatic dye-sensitized solar cells

A novel metal-free "black dye" was designed and synthesized for panchromatic dye-sensitized solar cells. Based on this dye, the broader incident photon-to-current conversion efficiency spectrum was obtained over the whole visible range extending into the near-IR region up to 920 nm

Molecular Design of Anthracene-Bridged Metal-Free Organic Dyes for Efficient Dye-Sensitized Solar Cells

Metal-free org. dyes bridged by anthracene-contg. π-conjugations were designed and synthesized as new chromophores for dye-sensitized solar cells (DSSCs). Studies on the relation between the dye structure, photophys. properties, electrochem. properties and performances of the DSSCs are described. With the introduction of the anthracene moiety, together with a triple bond for the fine-tuning of mol. planar configurations and to broaden absorption spectra, the Jsc and Voc of DSSCs improved. The improvement of Jsc is attributed to a broader absorption spectra of the dyes with the anthracene moiety. EIS anal. reveals that the anthracene moiety suppresses charge recombination arising from electrons in TiO2 films with I3- ions in the electrolyte, thus improving Voc. From optimized mol. structures and DSSC test conditions, the dye TC501 shows a prominent solar energy conversion efficiency up to 7.03% (Jsc = 12.96 mA/cm2, VOC = 720 mV, ff = 0.753) under simulated AM 1.5 irradn. (100 mW/cm2)