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ISSN 1674-2850
CN 11-9150/N5
 
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July 15,2017
Volume 10,Issue 13
Pages -
Subject Area:Condensed Matter Physics,Applied Statistical Mathematics
 
Title: Rapid construction of the N-spiro-azabiindane skeleton
Authors: CHENG Yuegang, ZHANG Min
PP: 1439-1445
Abstract: In this paper, the first preparation of N-chiral quaternary ammonium salts 14 possessing a N-spiro-azabiindane skeleton has been achieved in synthetically useful yield over multi-step from readily available compounds 10. The key transformations include a reductive amination of indoline and an intramolecular SNAr reaction. This work paves the base for the development of new chiral spiro ligands.
Keywords: organic chemistry; N-spiro-azabiindane; chiral quaternary ammonium salt; spiro ligands
 
Title: Impact of high energy ball-milling method on the structure and properties of Li3Mg2NbO6 ceramic
Authors: FENG Qinqin, LIU Peng, FU Zhifen
PP: 1512-1518
Abstract: Li3Mg2NbO6 ceramics are prepared by high energy ball-milling at 900-1 000℃ for the first time. The average grain size of Li3Mg2NbO6 nanopowders is 341 nm by high energy ball-milling, which is important to reduce the sintering temperature of ceramic. X-ray diffraction (XRD) patterns show that the components have no significant changes with increased sintering temperature, which means Li3Mg2NbO6 ceramics have a well-dense microstructure accompanying a minor of the second Nb2O5 phase. Because the existence of Nb2O5, worsens the microwave dielectric properties of the ceramics, and the density of ceramics is 3.72 g/cm3 at 950℃. Excellent microwave dielectric properties of Li3Mg2NbO6 ceramics are: εr = 16.85, Q×f = 25 400 GHz, τf =-21.96×10^-6/℃. XRD patterns of Li3Mg2NbO6 ceramics co-fired with Ag at 950℃ for 2 h indicate that no chemical reaction takes place between the main phase and Ag, indicating that the low-temperature sintered ceramics are excellent materials and suitable for the low temperature co-fired ceramic (LTCC) application.
Keywords: condensed matter physics; high energy ball-milling; microwave dielectric ceramics; low temperature co-fired ceramic; quality factor; temperature coefficient of the resonant frequency
 
Title: Comprehensive evaluation and application of customized bus commuter routes
Authors: TAN Zijian, ZHANG Suhua, ZHOU Jingjing, ZHAO Dongfang
PP: 1534-1543
Abstract: In the ideal simplified model, measuring the optimal path planning criteria is based on the total distance in terms of the minimum distance. For line planning problems of the city, especially the optimal design of bus lines, more complex and practical factors must be faced. In this paper, take Wuhan City for example, based on the multi-objective particle swarm optimization (PSO) algorithm, we try to find the impact of urban customized bus line planning on the main related factors. Then we establish the relevant evaluation system to obtain the customized bus line commuting multi-objective comprehensive evaluation, which determines the optimal path and the passing stop stations to meet the actual needs and conditions.
Keywords: operational research; mathematical modeling; customized bus; particle swarm optimization algorithm; commuter index; line planning
 
Title: Fabrication of two tombarthite co-doped TiO2 nanotube arrays and photoelectrocatalytic performance
Authors: YIN Yunchao, XUE Peng, WAN Jun, LIU Enzhou, HU Xiaoyun, FAN Jun
PP: 1482-1487
Abstract: TiO2 nanotube arrays (TiO2 NTs), Gd/Ce and Gd/Tm co-doped highly ordered TiO2 nanotube arrays (Gd/Ce-TiO2 NTs and Gd/Tm-TiO2 NTs) were synthesized through a two-step anodization method. The morphology, crystallinity and light absorption capability of samples were characterized. Compared with un-doped TiO2 NTs, Gd/Ce-TiO2 NTs and Gd/Tm-TiO2 NTs exhibited excellent visible light absorption capability which is caused by the formation of impurity energy states near the band edges. And the Gd/Tm-TiO2 NTs exhibited the higher current density than that of the un-doped TiO2 NTs and Gd/Ce-TiO2 NTs. Besides, the photoluminescence (PL) intensity of TiO2 NTs and Gd/Ce-TiO2 NTs was higher than that of Gd/Tm-TiO2 NTs, revealing a decrease in charge carrier recombination of Gd/Tm-TiO2 NTs, which is ascribed to the impurity energy states acting as the trapping sites for the photo-generated charges to reduce the recombination process. The photoelectrocatalytic performances of the Gd/Tm-TiO2 NTs have been significantly enhanced compared to that of un-doped TiO2 NTs and Gd/Ce-TiO2 NTs, which is due to the synergy effect of impurity energy states between the enhanced light absorption and the increased charger-separation efficiency.
Keywords: other subjects of chemical engineering; TiO2 NTs; co-doped; impurity energy states; anodization method
 
Title: Chitosan encapsulated EGCG loaded microspheres and its biological application study
Authors: LIU Yingyi, LIU Liwei, HU Siyi, WANG Yue, YUE Jie, QIN Pei, HUANG Yulin, LIANG Yaotian
PP: 1493-1498
Abstract: In this paper, the biological applications of drug loaded nanospheres composed of chitosan (CS) and (-)-epigallocatechin gallate (EGCG) were studied. Firstly, the drug loaded nanospheres were prepared by coupling chitosan with EGCG, and the successful coupling was proved by agar gel electrophoresis. The colloidal stability were monitored in the phosphate buffer saline (PBS) environment in 101 h, the results showed that the microspheres had no obvious aggregation, precipitation and degradation in 101 h, and the dynamic light scattering particle size monitoring results showed that the particle sizes remained stable, which indicated CS-EGCG nanospheres have good biological stability. Finally, we conducted a research in the biological application of in vivo and in vitro, in which the preparated nanospheres were used in mouse breast cancer model. The tumor size of CS-EGCG nanospheres injection group was decreased and showed good inhibitory effect on MCF-7 breast cancer, and the inhibition effect was better than chitosan injection group and EGCG injection group. On this basis, the functional modification was carried out to achieve the targeted fluorescent labeling effect of drug loaded microspheres on MCF-7 breast cancer cells. Drug loaded nanospheres show wide application prospects in the biomedical field.
Keywords: optics; drug loaded nanospheres; inhibition; tumor
 
Title: Fabrication of ordered nanostructures by mask method and its optical property study
Authors: CHANG Lingxia, YE Shunsheng, WANG Hongyu, ZHANG Junhu
PP: 1473-1481
Abstract: The mask of gold porous film was successfully prepared on a polymethylmethacrylate (PMMA)/glass substrate by membrane transfer using colloidal crystals and O2 reactive ion etching (RIE) techniques. Highly ordered nanostructure arrays with different morphologies were fabricated by the mask method. Etching the glass substrate with HF solution realized the transfer of the gold porous film mask, which solved the problem of wrinkling and rupturing in the traditional membrane transfer process greatly. The Ag nanodiscs array, Ag nanopillars array and Ag di-nanocrescents arrays were constructed by changing the etching time and the thermal deposition angle of the metal material utilizing the same template. The influences of changing its parameters on the surface plasmon resonance absorption peak were studied. In addition, this mask method can be used to fabricate nanostructures of composite, such as Ag-SiO2-Ag sandwich structure.
Keywords: polymer chemistry; nanostructure; mask method; surface plasmon resonance (SPR)
 
Title: Advance research in the total synthesis of pseudolaric acids: an anticancer natural product
Authors: LI Yun, GUO Rui, ZHAI Hongbin
PP: 1425-1438
Abstract: Pseudolaric acids display an anti-angiogenic role in a variety of cancer cell lines including hepatoma, breast, cervical and prostatic cancer, therefore they inhibit the proliferations of tumor cells. The total synthesis of this kind of compound has received considerable attentions from synthetic community. In this paper, recent advances in the total synthesis of pseudolaric acids analogs are reviewed. It shows the strategies in which the researchers have tried to construct their unique skeletons and the ways they have employed to solve the synthetic challenges. That information will benefit the synthetic strategies of pseudolaric acids in the future.
Keywords: organic chemistry; total synthesis of natural products; review; pseudolaric acids; anticancer
 
Title: Catalytic performances of bimetalic xNiyCo catalysts over carbon dioxide reforming methane: influences of preparation methods and pore structures of the support
Authors: WU Hao, YANG Weiwei, HE Dehua
PP: 1457-1464
Abstract: xNiyCo/SBA-15-CD and xNiyCo/SBA-15 catalysts were prepared using ordered mesoporous SBA-15 as the support through the β-CD assisted wet impregnation method and traditional impregnation method (without β-CD addition), respectively. While, xNiyCo/SiO2-CD catalyst was prepared using conventional SiO2 as the support through the β-CD assisted wet impregnation method. These catalysts were characterized by low temperature N2/adsorption-desorption, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD) and H2 temperature programmed reduction (H2-TPR) methods. Besides, these catalysts were employed to catalyze the carbon dioxide reforming of methane (CRM) reaction to evaluate the influence of the β-CD addition (different preparation methods) and pore structures of the support on the catalytic performances of the catalysts. The xNiyCo/SBA-15-CD catalyst, prepared with β-CD addition, behaved much higher dispersion and stronger metal-support interaction, which induced better behavior in the CRM reaction.
Keywords: physical chemistry; β-CD; SBA-15; bimetalic catalysts; highly dispersed; carbon dioxide reforming of methane reaction
 
Title: Effect of grain boundary on levitation forces of GdBCO superconducting bulks
Authors: ZHANG Chunyan, YANG Wanmin
PP: 1499-1505
Abstract: Based on the feature of five secondary domains of the single domain REBCO superconducting bulks (RE=Y, Gd, Sm, Nd, et al.), the crystal morphology and grain boundary change rule of the single seed crystal and multi-seed crystal (n=1, 2, 3, 4) REBCO superconducting bulks are simulated in each domain by using Auto CAD software under the condition of same seed orientation, seed distance and seed angle. By Gd+011 top-seed infiltration and growth technique, a group of GdBCO superconducting bulks of 30 mm in diameter with different numbers of seeds (n=1, 2, 3, 4) have been fabricated successfully. Based on grain boundary variation chart of multi-seed crystal samples drew by Auto CAD, we speculate that the grain and domain boundary will impact the levitation force of GdBCO superconducting bulks. Experiment results indicate that the more available grain boundary is, the worse critical current of superconducting properties is. The sample’s microstructure, critical current density and the test results of the magnetic levitation force are found in exact accordance with our projections after an in-depth research and analysis.
Keywords: condensed matter physics; multi-seed crystal; GdBCO bulks; critical current density; microstructure; levitation force
 
Title: Synthesis and visible-light photocatalytic performance study of Graphene/MoS2 micro/nano-composites
Authors: ZHANG Zheng, LI Jinhua, CHU Xueying, XU Mingze, JIN Fangjun
PP: 1488-1492
Abstract: Graphene/MoS2 composites were successfully prepared by hydrothermal method. The photocatalytic activity of Graphene/MoS2 composite was studied by controlling methylene blue (MB) degradation. The experimental results show that, compared with the single MoS2 material, Graphene/ MoS2 composites exhibit better photocatalytic degradation efficiency under the visible-light condition and MB dye simulated pollutants. The photocatalytic degradation rate is up to 76.6% after 180 min of visible-light, which is far higher than MoS2 material (38.6%). The results show that Graphene/MoS2 composites exhibit superior photocatalytic performance in the degradation of pollutants.
Keywords: optics; Graphene/MoS2; visible-light brand; photocatalytic degradation
 
Title: Synthesis and properties of diphenylphosphoryl modified oxazoles electron transport materials
Authors: XING Zhenhua, MENG Hua, XU Xiaoping, JI Shunjun
PP: 1446-1456
Abstract: Two diphenylphosphoryl substituted oxazoles, namely 2-[5-(diphenylphosphoryl)pyridin-2-yl]- 4,5-dip-tolyloxazole (OPO1) and 4,5-bis[4-(diphenylphosphoryl)phenyl]-2-(pyridin-2-yl)oxazole (OPO2) were synthesized and developed as electron transport materials. The thermodynamics, photo physical and electrochemical characteristics of the compounds were investigated systematically, which match well with the density functional theory (DFT) calculations. These two compounds have good thermal stability and very high glass transition temperature, the devices without obvious roll-off were stable by using OPO1 as electronic transport materials. For the first time, 2-pyridoxazole is used as nuclear structure in the electron transport material. By modifyed with diphenylphosphoryl, the compounds exhibit good thermal stability.
Keywords: organic chemistry; electron transport material; optimization; organic light-emitting diode
 
Title: An empirical study on analysis and forecast of big data of on-line users and off-line users in communication enterprises
Authors: ZHANG Weidong, WU Junliang
PP: 1525-1533
Abstract: In recent years, research and application of big data have been aroused wide attention of academia and enterprises. Governments have also given sufficient attentions and supports to it on the strategic and policy levels. This paper starts from the modern communication enterprises, uses the theoretical basis and technical system of big data to make an empirical study on the behaviors of on-line users and off-line users in the communication industry. In particular, the big data processing methods are also used to analyze the data of post-paid mobile users to build a mobile users’ on-line and off-line identification model, and forecasts users’ off-line risks. Based on the input output correlation (IOC), this paper gives the class dichotomy method to improve the efficiency of modeling. This method not only solves the problem that the optimal combination of variable attributes to be selected in the process of modeling optimization of radial basis function (RBF) artificial neural network, but also accelerates the speed of selecting the optimal variables, thus improves the accuracy of the model.
Keywords: applied statistical mathematics; big data; theoretical basis; technological system; communication; forecast
 
Title: Nanoscale Mn/Fe porphyrin based metal-organic frameworks for the catalysis of alkene epoxidation
Authors: CHANG Lan, YAO Xiyuan, ZHAO Fangyao, LI Yue
PP: 1465-1472
Abstract: In this paper, Mn and Fe porphyrin based metal-organic framework (MOF) catalysts (MOF-Mn and MOF-Fe) were synthesized by the solvothermal reaction among MTCPPCl [M for Mn or Fe, H2TCPP=5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin], Zn2+ (used as metal node) and 4,4’-bipyridine (bpy, used as auxiliary ligand). Both of these catalysts present nanoscale particle sizes and homogeneous morphology. MOF-Mn and MOF-Fe could be used to promote the epoxidation of a series of alkene substrates, and exhibited good activity, selectivity and stability in reactions. By the comparison with the catalytic performance of free metalloporphyrin ligands, we assume that the axial coordination of 4,4’-bipyridine to the metal center of metalloporphyrin component is crucial to the high selectivity of MOF-Mn and MOF-Fe.
Keywords: physical chemistry; metal-organic framework; metalloporphyrin; nanoscale; alkene epoxidation
 
Title: Trajectory dynamics for Lévy flight
Authors: SUN Zhaopeng, ZHENG Yujun
PP: 1519-1524
Abstract: Lévy flight is a random walk process that is characterized by the occurrence of extremely long jumps in which show a long-tailed probability distribution. In this paper, a new method called entangled trajectory is introduced to understand the Lévy flight behaviors. This method is based on the kernel density estimation and represents the probability density function by a finite number of sampling points. It has several merits such as simple in algorithm, high efficiency for computation and it is easily extended to multidimensional system. Two cases of Lévy stable processes, the free Lévy flight of a Cauchy quartic potential are presented and discussed. The entangled trajectory results are in good agreement with the exact solutions.
Keywords: statistical physics; Lévy flight; anomalous diffusion; entangled trajectory
 
Title: Crystal structure and electronic properties studies for P4-carbon allotropes using first-principles method
Authors: LI Qingkun, LI Zhiyuan, WEN Dianzhong
PP: 1506-1511
Abstract: The carbon allotropes with P41212 space group structure were reported and investigated by using the first-principles method. In this paper, we called the carbon allotrope P4-carbon. The crystal structure of P4-carbon was calculated by generalized-gradient-approximation method. The stability of P4-carbon was also discussed based on stiffness coefficient calculation and phonon spectrum analysis. Furthermore, the band structure and density of states have also been analyzed. Finally, we got the Young’s modulus along the [001] crystal orientation of P4-carbon, which is 1 015 GPa. Furthermore, the P4-carbon also exhibits the semiconductor characteristics with energy gap of 1.45 eV. The results will promote the studies of the crystal structure and electronic properties for carbon allotropes.
Keywords: condensed matter physics; carbon allotropes; P4-carbon; first-principles