Chen Z.,University of Alberta |
Chen Z.,Heilongjiang Academy of science |
Hu L.,University of Alberta |
Serpe M.J.,University of Alberta
Journal of Materials Chemistry | Year: 2012
We present a new method to synthesize hydrogel particles by exploiting the interface formed between two immiscible liquids. Spherical monomer droplets, of varying diameters, could be suspended at the planar interface formed between two immiscible liquids. While suspended, polymerization could proceed, after which the hydrogel particles that were formed could be collected. Using this approach, we were able to synthesize particles containing various monomers/co-monomers including: N-isopropylacrylamide, 2-hydroxyethyl methacrylate, and N-(3-aminopropyl)methacrylamide hydrochloride. The approach also allowed for the facile encapsulation of various inorganic nanoparticles and small molecules, including: Au nanoparticles, Ag nanoparticles, magnetic cobalt (Co) nanoparticles, tris(4-(dimethylamino)phenyl)methylium chloride (crystal violet) and fluorescein isothiocyanate isomer I (FITC). The benefit of this approach is the ability to load polymer particles with a wide variety of moieties without the need to optimize any reaction conditions. So long as the species to be encapsulated in the particle are soluble in water, and minimally soluble in the solvents used to form the interface, they will be incorporated in the polymerized particle. This journal is © 2012 The Royal Society of Chemistry.
Dong Z.,Henan Normal University |
Yuwen Y.,Henan Normal University |
Wang Q.,Henan Normal University |
Chen G.,Henan Normal University |
Liu D.,Heilongjiang Academy of science
Gene Expression Patterns | Year: 2012
Dugesia japonica has become the suitable model system for studying the visual system molecular developmental processes because of their simple structure and high regenerative capacity. To further dissect the molecular events of genetic network controlling the visual system regeneration in D. japonica, we investigated the morphogenesis of regenerating eyes under the stereomicroscope and the transcripts expression levels of eight genes involved in this process by quantitative real-time PCR. The eight genes were Djeya, Djsix-1, Eye53, DjotxA, Djpax6, Djopsin, Djnetrin and 1020HH. The results showed that each gene was of different expression pattern at distinct regeneration stage and these eight genes could be divided into three groups according to the expression levels at different time points and the morphogenesis during eye reconstruction: (1) the early expression group, including Djeya, Djsix-1, Eye53, and DjotxA, which expression levels were significant increase from 1 to 3 days after amputation; (2) the medium-term expression group, only including one gene, Djpax6, which expression level reached the peak on day 5; and (3) the late expression genes, including Djopsin, Djnetrin and 1020HH, which gradually increase transcription with the eye regeneration. Our data suggested that eye reconstruction was the results of polygenic services and the genes in the same group might have similar role or function in symphony. © 2011 Elsevier B.V. All rights reserved.
Gao J.,Heilongjiang University |
Wang L.,Heilongjiang University |
Kan K.,Heilongjiang University |
Kan K.,Heilongjiang Academy of science |
And 6 more authors.
Journal of Materials Chemistry A | Year: 2014
The mesoporous Al2O3-In2O3 composites with one-dimensional (1D) nanofibres (NFs) have been fabricated via a facile one-step synthesis of the electrospinning approach, followed by appropriate thermal treatment under ambient conditions. The composite nanomaterials display high dispersion of both In2O3 and Al2O3, forming a heterostructure and mesoporous tubular structure in a broad Al:In atomic ratio up to 1:4. It has been found that the Al2O3 composite tube-like nanostructures not only increase efficient sites for gas adsorption, but also possess higher donor densities. Moreover, the mesoporous structure also provides effective and fast channels for fast capturing and migration of electrons. The results show that the mesoporous Al2O3-In2O3 nanotubes exhibit excellent sensing properties to NOx down to a detection limit of 291 ppb at room temperature (RT), while containing 20 at% Al2O 3 (labeled as meso-20AI NTs) with an average diameter of nanoparticles of about 10 nm. With respect to the 97 ppm NOx, the maximum response of 100 was determined, 7.3 times as high as the pure In 2O3 NTs. Owing to its unique composite structure, 1D meso-20AI NTs may be promising for application in gas sensors. © 2014 The Royal Society of Chemistry.
Bai X.-F.,Heilongjiang Academy of science |
Cao Y.,Heilongjiang University |
Wu W.,Heilongjiang University
Renewable Energy | Year: 2011
The H2 production rate from H2S photocatalytic decomposition under visible light irradiation (λ > 400 nm) over CdS nanoparticules formed in HY-zeolite pore (named CdS/HY) was much higher compared to the commercial bulk CdS. The CdS/HY photocatalyst was characterized by UV-Vis, XRD, FT-IR, N2 adsorption, SEM and HRTEM. The blue shift from bulk which confirmed CdS nanoparticles located in the pore of HY-Zeolite (named HY). Photocatalytic activity and surface area were enhanced by such structures. © 2010 Elsevier Ltd.
Bai X.,Heilongjiang Academy of science |
Bai X.,Heilongjiang University |
Li J.,Heilongjiang University
Materials Research Bulletin | Year: 2011
Hexagonal ZnIn 2S 4 porous microspheres were synthesized via a cetylpyridinium bromide (CPBr)-assisted hydrothermal method. The structure, morphology and optical property of these prepared products were characterized by wide angle X-ray diffraction (WAXRD), small angle X-ray diffraction (SAXRD), UV-Vis diffusive reflectance spectroscopy (DRS), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analyzer (EDX) and nitrogen sorption analysis. The effects of CPBr and pH on the crystal structure, morphology and photocatalytic activity of ZnIn 2S 4 products were studied. The results demonstrated that the flowerlike ZnIn 2S 4 microspheres, which were composed of numerous nanosheets, performed higher visible-light photocatalytic activity than bulk ZnIn 2S 4 for hydrogen evolution. The CPBr addition influenced the crystal structure including the position and intensity of some peaks. Furthermore, the pH played a crucial role in the formation of ZnIn 2S 4 porous microspheres. The as-synthesized porous ZnIn 2S 4 microspheres possessed the specific surface area of 165.4 m 2 g -1 and the slit-like porous configuration, which was beneficial to photocatalytic reaction. © 2011 Elsevier Ltd. All rights reserved.
Lou C.,Qiqihar University |
Xianzhi K.,Heilongjiang Academy of Science |
Jianxin W.,Qiqihar University |
Liqun M.,Qiqihar University
Journal of Applied Polymer Science | Year: 2012
A new soften curing agent for toughening epoxy resins was synthesized by m-phenylene diamine modified with epoxypropyl butyl ether. The curing processes of epoxy resin/modified m-phenylene diamine were traced by differential scanning calorimetry (DSC), then kinetic parameters, ΔE and n, were deduced. Fourier transform infrared (FTIR) analysis showed that the longer the reaction time was, the smaller the absorption peaks of epoxy group were. The results of the mechanical properties demonstrated that the impact property of the epoxy resin cured by modified m-phenylene diamine at the moderate temperature was better than that of cured by unmodified one because of the introduction of soft ether chain. Copyright © 2011 Wiley Periodicals, Inc.
Liu F.,Hong Kong Polytechnic University |
Zhang D.,Hong Kong Polytechnic University |
Song C.,Heilongjiang Academy of science |
Lu G.,Harbin Institute of Technology
IEEE Transactions on Instrumentation and Measurement | Year: 2013
Touchless fingerprint capture devices have the advantage over traditional touch-based approaches of being hygienic and preventing distortions resulting from the contact of fingers. Single-view acquisition systems bring in problems, such as scene difference and a limited effective area. This paper thus presents a touchless multiview fingerprint capture system that acquires three different views of fingerprint images at the same time. This device is designed by optimizing parameters regarding the captured fingerprint image quality and device size. A fingerprint mosaicking method is proposed to splice together the captured images of a finger to form a new image with a larger useful print area. Optimization design of our device is demonstrated by introducing our design procedure and comparing with current touchless multiview fingerprint acquisition devices. The efficiency of our device is further proved by comparing recognition accuracy between mosaicked images and touch-based fingerprint images. Experimental results also show that our proposed mosaicking method is more robust to low ridge-valley contrast fingerprint images than available methods. The effectiveness of our mosaicking method is further proved by comparing equal error rates with the mosaicking algorithms evaluated on our established database of 541 fingers. © 1963-2012 IEEE.
Wang H.,Heilongjiang University |
Gao J.,Heilongjiang University |
Li Z.,Heilongjiang University |
Ge Y.,Heilongjiang University |
And 3 more authors.
CrystEngComm | Year: 2012
In this paper, three-dimensional (3D) flowerlike α-Ni(OH) 2 nanocrystals with hierarchical architectures were prepared through a one-step method. It was found that the 3D hierarchical nanostructures are actually composed of thin nanosheets or nanopetals, which consist of many ultrafine nanoparticles with 3-5 nm diameters. The growth mechanism for the hierarchical flowerlike nanocrystals is described as the process of nucleation, growth, stacking and self-assembly. The gas sensing properties of α-Ni(OH) 2 nanocrystals for NO x gas was investigated at room temperature and the sensing mechanism was discussed as two aspects: 1) relation between the porosity and diffusion, adsorption/desorption of the gas on the surface of the α-Ni(OH) 2 nanocrystals; 2) the effect of the chemical composition of the layered double hydroxide-like (LDHs-like) structure on the ability of proton transportation between adjacent NiOH layers and between overlapped ultrafine nanocrystals. The results demonstrate that the α-Ni(OH) 2 structures, synthesized by refluxing 0.07 mol L -1 Ni(NO 3) 2·2H 2O, not only presents excellent gas-sensing properties but also has good repeatability and a longer service life. These α-Ni(OH) 2 nanocrystals with 3D hierarchical structures and a unique chemical composition have significant implications for the practical application of gas sensors. This journal is © The Royal Society of Chemistry 2012.
Yuan L.,Harbin Institute of Technology |
Yuan L.,Heilongjiang Academy of Science |
Shen J.,Harbin Institute of Technology |
Chen Z.,Harbin Institute of Technology |
Liu Y.,Harbin Institute of Technology
Applied Catalysis B: Environmental | Year: 2012
The use of pumice for heterogeneous catalytic ozonation significantly enhances the degradation efficiency and the total organic carbon (TOC) removal of p-chloronitrobenzene (pCNB) in aqueous solution compared with ozonation alone because of the synergistic effect between ozone and the catalyst. The pCNB adsorption was too small to contribute significantly to the pCNB degradation during pumice-catalyzed ozonation. The decomposition rate of the aqueous ozone increased 1.374-fold in the presence of pumice. High pH also positively affected the pumice-catalyzed ozonation, as nearly uncharged surfaces (the solution pH was close to the point of zero charge) are favorable for catalytic pCNB ozonation. tert-Butanol remarkably decreases the removal efficiency of catalytic pCNB ozonation, which suggests that pCNB degradation follows the mechanism of hydroxyl radical oxidation. Increasing both the pumice and ozone concentrations enhanced the removal effectiveness of pCNB. Pumice is an efficient green catalyst for pCNB degradation in aqueous solution. © 2012 Elsevier B.V.
Sun Q.,Harbin Institute of Technology |
Chen X.,Harbin Institute of Technology |
Liu Z.,Harbin Institute of Technology |
Wang F.,Harbin Institute of Technology |
And 2 more authors.
Journal of Alloys and Compounds | Year: 2011
Infrared-to-visible upconversion luminescence spectra were investigated in Er3+ doped and Er3+-Li+ codoped BaTiO 3 nanocrystals following excitation with 976 nm. By introducing Li+ ions, the upconverted emission intensity is found to be greatly enhanced compared to that of the nanocrystals without Li+ ions. The enhanced luminescence might be attributed to the oxygen vacancy generated by Li+ ion incorporation in the lattices and the distortion of the local asymmetry around Er3+. We observe that excitation power dependence and decay time are increased by the incorporation of Li+ ions. Li+ ions also can reduce the OH groups in specimen, which decrease nonradiative decay from the 4S3/2 to 4F 9/2, enhancing the upconversion emission intensities. © 2011 Elsevier B.V.