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Yang X.,Beijing Institute of Technology | Zheng N.,Beijing Institute of Technology | Zheng N.,Key Laboratory of Cluster Science of Ministry of Education | Wen P.,Beijing Institute of Technology | And 2 more authors.
Powder Technology | Year: 2015

With appropriate spatial confinement to the upper surface of a vertically shaken granular mixture, an uncommon segregation behavior, horizontal segregation (HS) where two types of particles separate along the horizontal orientation, is found. By quantitatively tuning confined space above the granular bed, we plot different phase diagrams and find a qualitative dissimilarity. In particular, the HS disappears when the effect of confinement becomes weak. Additionally, we gradually evacuate air out of the container, and measure the segregation extent of HS as a function of air pressure. It is found that all the segregation behaviors change to mixed state at a low pressure. We also examine the existence of the HS with different granular mixtures and confinement boundaries. The experimental observation confirms that the formation of the HS depends on the interstitial air and confinement. © 2015 Elsevier B.V. Source

Chi W.-J.,Beijing Institute of Technology | Chi W.-J.,Key Laboratory of Cluster Science of Ministry of Education | Li Z.-S.,Beijing Institute of Technology | Li Z.-S.,Key Laboratory of Cluster Science of Ministry of Education | And 2 more authors.
Physical Chemistry Chemical Physics | Year: 2015

The electronic structures, optical properties and hole mobilities of 4-(4-phenyl-4- α-naphthylbutadieny)-triphenylamine and its five derivatives are investigated by density functional theory (DFT). The results show that the highest occupied molecular orbital (HOMO) of all molecules is almost fully delocalized throughout the whole molecule, and the substituents -N(CH3)2 and -C6H5 denoted as molecules 6 and 2, respectively, have the largest contribution to the HOMO, which is favorable for hole transfer integral and hole mobility. Spectrum analysis indicates that all molecules have large Stokes shifts based on absorption and emission spectra. In addition, it is found that the hole reorganization energy of all molecules is about 0.5 times compared to that of electrons, which implies that hole mobility is bigger than electron mobility. On the basis of predicted packing motifs, the hole mobilities (u) of all molecules are also obtained. The largest hole mobility of molecule 2 (0.1063 cm2 V-1s-1) is found to be higher than that of other molecules due to the face-to-face stacking mode, which suggests that -C6H5 is a good substituent group for improving hole mobility compared to other electron releasing groups. We hope that our results will be helpful for the further rational molecular design and synthesis of novel hole transport materials (HTMs) for high performance perovskite-type solar cells. © the Owner Societies 2015. Source

Xu C.,Beijing Institute of Technology | Zheng N.,Beijing Institute of Technology | Zheng N.,Key Laboratory of Cluster Science of Ministry of Education | Li L.-S.,Science and Technology on Electromagnetic Scattering Laboratory | Shi Q.-F.,Beijing Institute of Technology
Powder Technology | Year: 2016

We have experimentally investigated the bouncing behavior and damping performance of a container partially filled with granular chains, namely a chain-filled damper. The motion of the chain-filled damper, recorded by a particle tracing technology, demonstrates that the granular chains can efficiently absorb the collisional energy of the damper. We extract both the restitution coefficient of the first collision and the total flight time to characterize the dissipation ability of the damper. Two containers and three types of granular chains, different in size, stiffness and restitution coefficient, are used to examine the experimental results. We find that the restitution coefficient of the first collision of a single-chain-filled damper can linearly tend to vanish with increasing the chain length and obtain a minimum filling mass required to cease the container at the first collision (no rebound). When the strong impact occurs, the collisional absorption efficiency of a chain-filled damper is superior to a monodisperse-particle-filled damper. Furthermore, the longer the chains are, the better the dissipative effect is. © 2016 Elsevier B.V.. Source

Liu C.,Key Laboratory of Cluster Science of Ministry of Education | Shao C.,University of Jinan | Wu H.,University of Jinan | Guo B.,University of Jinan | And 2 more authors.
RSC Advances | Year: 2014

Recently, growing attention has been paid to the accurate determination of hydrogen peroxide (H2O2) for elucidating its detailed biological function in physiology and pathology. A fluorescence method with the help of a fluorescent probe is the preferred technique for in situ visualization of biologically important species in vivo, even in single living cells. In the present manuscript, we developed a simple, fast response and highly selective fluorescent probe (1) with a receptor of the boronate moiety for the ratiometric imaging of H2O2 in living cells. Probe 1 could quantifiably detect H2O2 in the range of 18-540 μM by a ratiometric fluorescence spectroscopy method with a detection limit of 4 μM. Importantly, probe 1 exhibited 81 nm red-shifted absorption spectra accompanied by the color changes from colorless to yellow, and 100 nm red-shifted emission spectra upon addition of H2O2. Thus, 1 can serve as a "naked-eye" probe for H2O2. Preliminary bioimaging application and low cytotoxicity investigations further demonstrated that the proposed probe would be of great benefit to biomedical researchers for investigating the detailed biological function of H2O2 in biological systems. This journal is © the Partner Organisations 2014. Source

Du G.,Key Laboratory of Cluster Science of Ministry of Education | Long Y.,Beijing Institute of Technology | Xue J.,Key Laboratory of Cluster Science of Ministry of Education | Zhang S.,Key Laboratory of Cluster Science of Ministry of Education | And 2 more authors.
Macromolecules | Year: 2015

The regioselective coordination-insertion polymerization of 1,3-cyclohexadiene (CHD) and copolymerization with styrene (S) could be achieved by cationic half-sandwich fluorenyl rare earth metal alkyl catalysts generated by treating half-sandwich fluorenyl rare earth metal dialkyl complexes Flu'Ln(CH2SiMe3)2(THF)n (1-10) with an activator (such as [Ph3C][B(C6F5)4] (A), [PhNHMe2][B(C6F5)4] (B), or B(C6F5)3 (C)) and AliBu3. The homopolymerization of CHD afforded poly(CHD)s with complete 1,4 selectivity (1,4 selectivity up to 100%). The copolymerization of CHD with styrene gave new random CHD-S copolymers with CHD content ranging from 22 to 74 mol % containing 1,4-linked CHD-CHD, alternating CHD-S, and syndiotactic S-S sequences unavailable previously. The activity of the copolymerization and the comonomer compositions and sequences of the resulting CHD-S copolymers could be easily controlled by changing the substituted fluorenyl ligand, the metal center, the activator, the temperature, and the molar ratio of comonomers. The residual C-C double bonds of the random CHD-S copolymers could be further epoxidized by meta-chloroperoxybenzoic acid (mCPBA) at room temperature to prepare high-performance polymers with polar groups and reactive sites in the polymer backbone. Such functionalization could improve the solubility, dying, acidity, and surfactivity of these copolymer materials. © 2015 American Chemical Society. Source

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