Harbin Engineering University

About: Harbin Engineering University is a education organization based out in Harbin, Heilongjiang, China. It is known for research contribution in the topics: Control theory & Computer science. The organization has 31149 authors who have published 27940 publications receiving 276787 citations. The organization is also known as: HEU.

Improvement of g-C3N4 photocatalytic properties using the Hummers method.

Abstract: In this study, graphitic C3N4 (g-C3N4) with high photocatalytic properties to methylene blue (MB) was synthesized by treating the bulk g-C3N4 using the Hummers method. The bulk g-C3N4 was obtained by calcining dicyandiamide. The g-C3N4 treated by the Hummers method (E-g-C3N4) was characterized and utilized for the photocatalytic removal of MB. The results showed that the Hummers treatment exfoliated the nanosheets bulk g-C3N4 into nanorods and improved the dispersion of E-g-C3N4 in an aqueous solution. It also distinctly enhanced the photocatalytic activity of g-C3N4 to MB, i.e., the removal efficiency increased from 38.45% for the bulk g-C3N4 to 96.61% for the E-g-C3N4.

NiO/Ni/TiO2 nanocables with Schottky/p-n heterojunctions and the improved photocatalytic performance in water splitting under visible light.

Abstract: Construction of Schottky junction or p-n heterojunction is admitted as an effective way for improving the separation of photo-induced carriers through its built-in electric field. In this work, fabrication of cooperative Schottky and p-n (SPN) heterojunction has been realized by intercalating metal Ni into a NiO/TiO2p-n junction, forming a NiO/Ni/TiO2 Sandwich-like heterojunction. The special heterostructure was confirmed by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and the high-resolution transmission electron microscopic (HRTEM), Brunauer Emmett Teller (BET). After a serial of contrast experiments with solo Schottky or p-n junction, it was found that the electron-hole separation in this NiO/Ni/TiO2 SPN heterojunction was enhanced through charge transfer channel, and it was also in accordance with their related optical and photoelectrical properties characterizations, such as photoluminescence (PL) spectrum and UV-Vis diffused reflectance spectra. In the following photocatalytic water splitting process under visible light, the hydrogen generation rate of NiO/Ni/TiO2 reached up to 4653 μmol h-1 g-1, which was 10.2, 6.7 and 2.3 times of those of TiO2 (457 μmol h-1 g-1), Ni/TiO2 (691 μmol h-1 g-1) with a Schottky junction and NiO/TiO2 (2059 μmol h-1 g-1) with a p-n junction, respectively. This SPN heterojunction with excellent photo-induced electron-hole separation ability opens a new window to exploring photocatalyst for water splitting.

Effects of Ce-rich RE additions and heat treatment on the microstructure and tensile properties of Mg-Li-Al-Zn-based alloy

Abstract: As-cast Mg–5Li–3Al–2Zn– x RE ( x = 0–2.5 wt.%) alloys were prepared under the ambient of pure argon, and the effects of Ce-rich rare earths (RE) and heat treatment on the microstructure and mechanical properties of Mg–Li–Al–Zn-based alloy were investigated. The results show that the main phase compositions of Mg–5Li–3Al–2Zn (LAZ532) alloy consist of α-Mg and AlLi. With the addition of RE, Al-RE precipitate forms, and increases gradually, whereas AlLi phase decreases. The room temperature tensile test reveals that the addition of RE could clearly improves the mechanical properties of alloys which are further improved after heat treatment. In more detail, excellent tensile strength and ductility are obtained in 1.5 wt.% RE containing alloy in as-cast state. After heat treatment, the 1.0 wt.% RE containing alloy attains superior tensile strength. The differences in tensile strength are related to the morphology, distribution of second phases and solid–solution strengthening in different alloy systems. In addition, the fracture pattern of the alloy is predominantly brittle cleavage and tends to be quasi-cleavage with RE addition.

Bioresponsive and near infrared photon co-enhanced cancer theranostic based on upconversion nanocapsules

Abstract: Developing nanotheranostics responsive to tumor microenvironments has attracted tremendous attention for on-demand cancer diagnosis and treatment Herein, a facile Mn-doping strategy was adopted to transform mesoporous silica coated upconversion nanoparticles (UCNPs) to yolk-like upconversion nanostructures which possess a tumor-responsive biodegradation nature The huge internal space of the innovated nanocarriers is suitable for doxorubicin (DOX) storage, besides, the Mn-doped shell is sensitive to the intratumoral acidity and reducibility, which enables shell biodegradation and further accelerates the breakage of Si-O-Si bonds within the silica framework This tumor-responsive shell degradation is beneficial for realizing tumor-specific DOX release Subsequently, polyoxometalate (POM) nanoclusters that can enhance photothermal conversion in response to the tumor reducibility and acidity were modified on the surface of the silica shell, thereby achieving NIR-enhanced shell degradation and also preventing premature DOX leakage The as-produced thermal effect of the POM couples with the chemotherapy effect of the released DOX to perform a synergetic chemo-photothermal therapy Additionally, the shell degradation brings size shrinkage to the nanocarriers, allowing faster nanoparticle diffusion and deeper tumor penetration, which is significant for improving theranostic outcomes Also, the drastic decline of the red/green (R/G) ratio caused by the DOX release can be used to monitor the DOX release content through a fluorescence resonance energy transfer (FRET) method The MRI effect caused by Mn release together with the MRI/CT/UCL imaging derived from Gd3+/Yb3+/Nd3+/Er3+ co-doped UCNPs under 808 nm laser excitation endow the nanosystem with multiple imaging capability, thus realizing imaging-guided cancer therapy