Zhengzhou Kindergarten Teachers College

Zhengzhou, China

Zhengzhou Kindergarten Teachers College

Zhengzhou, China
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Ma W.-J.,Zhengzhou Kindergarten Teachers College | Li G.-T.,North China University of Water Conservancy and Electric Power
Acta Crystallographica Section C: Crystal Structure Communications | Year: 2013

The title compound, [Zn(C8H6N4O 3)] n or [Zn(L)]n [H2 L is 3-(6-oxo-6,9- dihydro-1H-purin-1-yl)propionic acid], crystallized as a nonmerohedral twin. The ZnII cation is four-coordinated, ligated by two carboxylate O atoms from two L ligands and two N atoms from another two ligands. Each ligand bridges four ZnII centres, extending the structure into a three-dimensional polymer with a 4-connected (65,41) topological structure containing two-dimensional homochiral layers constructed from one-dimensional metal-organic helices. Investigation of the thermal stability of the compound shows that the network has very high thermostability and is stable up to 720 K. © 2013 International Union of Crystallography.


Xue H.,Beihang University | Xie Y.,Beihang University | Dai H.,Zhengzhou Kindergarten Teachers College | Yu J.,Beihang University | Ma W.,Science and Technology on Space Physics Laboratory
Beijing Hangkong Hangtian Daxue Xuebao/Journal of Beijing University of Aeronautics and Astronautics | Year: 2016

Based on the centrifugal machine system, a test apparatus was set up to investigate the operating characteristics of dual compensation chambers loop heat pipe (DCCLHP) under both gravity and acceleration fields. The ranges of the heat load and the magnitude of acceleration are 25-300 W and 3 g-9 g, respectively. The influences of different heat loads, acceleration directions and magnitudes on temperature fluctuations of loop heat pipe were analyzed. The results indicate that the effect of the acceleration can change the start mode and operating performance of the DCCLHP. The temperature fluctuation at the outlet of the condenser and even around the whole loop can be restrained or wakened. But the operating temperature of the evaporator is nearly the same under the same heat load conditions. The inherent flow instability of the gas-liquid two phase flow can be enhanced by the acceleration effect which reinforces this unstable flow in reverse. Furthermore, the instability of the heat leak from the evaporator to the compensation chamber is enhanced. In addition, the cooling effect of the condenser can weaken the temperature fluctuation of the condensing pipe line. © 2016, Editorial Board of JBUAA. All right reserved.


Jia H.,Zhengzhou University | Jia H.,Zhengzhou Kindergarten Teachers College | Li Y.,Zhengzhou University | Xiong Z.,Zhengzhou University | And 2 more authors.
Dalton Transactions | Year: 2014

Five metal-organic frameworks, namely, [Mn3(H 2DMPhIDC)2(HDMPhIDC)2(bpp)]n (H 3DMPhIDC = 2-(3,4-dimethylphenyl)-1H-imidazole-4,5-dicarboxylic acid, bpp = 1,3-di(4-pyridyl)propane) (1), [Pb4(DMPhIDC) 2(OH)2]n (2), [Cd(HDMPhIDC)(en)]n (en = ethylenediamine) (3), [Cu3(HDMPhIDC)3(Py) 3]n (Py = pyridine) (4) and {[Zn2(HDMPhIDC) 2(Phen)2]2·H2O}n (Phen = 1,10-phenanthroline) (5) have been hydro(solvo)thermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental and thermal analyses and IR spectra. Polymer 1 displays a 3D noninterpenetrated framework with 1D open channels. Polymer 2 exhibits a stepped (4,4,4,4,6,6)-connect 2D topology. Polymer 3 is a left-handed helix chain. Polymers 4 and 5 arrange the 3D supramolecular networks containing a 1D corrugated chain via π⋯π stacking or hydrogen bond interactions. In these MOFs, the imidazole dicarboxylate ligand shows various coordination modes and strong coordination ability. Furthermore, the solid-state luminescent properties of the polymers have also been discussed. © 2014 The Royal Society of Chemistry.


Zhang G.,Zhengzhou Kindergarten Teachers College
Fenmo Yejin Jishu/Powder Metallurgy Technology | Year: 2016

In this paper, effects of copper-coated graphite content and particle size on the microstructure, physical and mechanical properties of the Cu/copper-coated graphite composite were studied. The results show that with the graphite content increased, the density, bending strength of material are reduced and the resistivity is increased. In Cu/Copper-coated graphite composite, the smaller particles have a higher density. However, the larger particles show well friction and wear behaviors, and they have a higher electrical conductivity than the smaller particles. © 2016, University of Science and Technology Beijing. All right reserved.


Geng Z.,Henan Normal University | Dai H.,Zhengzhou Kindergarten Teachers College | Chen X.,Henan Normal University | Wei S.,Henan Normal University | Xia C.,Henan Normal University
Superlattices and Microstructures | Year: 2013

Based on the effective mass approximation, the laser field effects on exciton states and optical properties in the direct-gap Ge/SiGe quantum well (QW) are investigated by means of a variational method. Numerical results show that the ground-state exciton binding energy and the emission energy are dependent highly on the well width and laser field amplitude in the direct-gap Ge/SiGe QW. The laser field decreases the exciton binding energy, however, it also increases the emission energy in the QW for any well width. In particularly, our results also show that the laser field has remarkable effects on exciton states and optical properties in the direct-gap Ge/SiGe QW with the small well width case. © 2013 Elsevier Ltd. All rights reserved.


Ma W.-J.,Zhengzhou University | Ma W.-J.,Zhengzhou Kindergarten Teachers College | Gao Z.-Y.,Zhengzhou University | Zhu S.,Zhengzhou University | Wu B.-L.,Zhengzhou University
Polyhedron | Year: 2014

Tetranuclear square grids, namely, [Cd4(L-O)4] ·1.5DMF (1), [Ni4(L-O)4]·H2O (2), [Zn4(L-O)4]·3H2O (3), [Zn 4(L-O)4] (4), [Cu4(L-O)4] ·H2O (5), and {[Cu4(L-O)4][Cu 4(L-O)4]}·2.5DMF·1.5H2O (6) (DMF = N,N-dimethylformamide, H2L-O = 2,6-bis(pyrazine-2-carboxamido) pyridine-N-oxide), formed by the reactions of M ions (M = CdII, NiII, ZnII and CuII) with pyridyldicarboxamide ligands 2,6-bis(pyrazine-2-carboxamido)pyridine (H2L), was fully characterized. Notably, the central pyridines of ligands H2L were oxidized into pyridine-N-oxides under air conditions, producing the new anionic ligands (L-O)2- to fabricate those grids. In those square grids every octahedrally coordinated metal node is chelated by two doubly deprotonated ligands (L-O)2- in the mer configuration, and each ligand (L-O) 2- acts as a rigid bis(tridentate) linker with the N carboxamide and one Npyrazine in each arm chelating metal ions plus the O atom in the pyridine-N-oxide group bridging the two bound M ions. The CdII and ZnII grids show uncommonly-excellent thermal stabilities and interesting green emissions. Magnetic studies upon grid [Ni4(L-O)4] suggest an antiferromagnetic coupling between the adjacent NiII mainly exchanged through μ-O with a coupling constant of J = -15.06 cm-1. © 2014 Published by Elsevier Ltd.


Jia H.,Zhengzhou University | Jia H.,Zhengzhou Kindergarten Teachers College | Luo X.,Zhengzhou University | Ma B.,Zhengzhou University | And 2 more authors.
Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry | Year: 2015

A novel coordination polymer, {[Mn3(3-m-MePhIDC)2(H2O)6]·3H2O}n (1), has been synthesized by hydrothermal reaction, employing 2-(m-methylphenyl)-1H-imidazole-4,5-dicarboxylic acid (m-MePhH3IDC) as organic ligand, and characterized by single-crystal X-ray diffraction, elemental analysis, PXRD, and IR spectra. It crystallizes in trigonal R3 space group and exhibits a 3D honeycomb-like framework constructed from Mn(II) ions and m-MePhIDC3- units. The thermal and magnetic properties of compound 1 have been investigated as well. © 2015 Taylor & Francis Group, LLC.


Jia H.,Zhengzhou University | Jia H.,Zhengzhou Kindergarten Teachers College | Li Z.,Zhengzhou University | Chen Q.,Zhengzhou University | Li G.,Zhengzhou University
Supramolecular Chemistry | Year: 2015

Two tetranuclear nickel(II) complexes, [Ni4 (p-BrPhHIDC)4(py)4(H2O)4]·CH3OH (p-BrPhH3IDC = 2-(p-bromophenyl)-1H-imidazole-4,5-dicarboxylic acid) (1) and [Ni4(p-ClPhHIDC)4 (CH3CN)4(H4O)44H2O (p-ClPhH3IDC = 2-(p-chlorophenyl)-1H-imidazole-4,5-dicarboxylic acid, py = pyridine) (2), have been solvothermally synthesised and structurally characterised. Both compounds consist of similar tetranuclear Ni(II) cores, in which the imidazole dicarboxylate ligands adopt the similar coordination mode. The thermal properties of 1 and 2 have been investigated. Also, it is discovered that there exists antiferromagnetic coupling between the Ni(II) ions in 1 and 2; the best fittings to the experimental magnetic susceptibilities gave J = - 9.89 cm- 1 and g = 2.18 for 1, and J = - 10.54 cm- 1 and g = 2.14 for 2. © 2015 © 2015 Taylor & Francis.


Zhai J.C.,Zhengzhou Kindergarten Teachers College
Applied Mechanics and Materials | Year: 2014

This paper designs the gas well bottom hole flowing pressure and well depth, directly checks gas compression coefficient nomograph, derives the corresponding mathematical model, and test its reliability in the design and test of drainage gas recovery on the basis of gas compression coefficient in different well depth via Katz gas compressibility chart. © (2014) Trans Tech Publications, Switzerland.


PubMed | Zhengzhou Kindergarten Teachers College
Type: Journal Article | Journal: Acta crystallographica. Section C, Crystal structure communications | Year: 2013

The title compound, [Zn(C8H6N4O3)]n or [Zn(L)]n [H2L is 3-(6-oxo-6,9-dihydro-1H-purin-1-yl)propionic acid], crystallized as a nonmerohedral twin. The Zn(II) cation is four-coordinated, ligated by two carboxylate O atoms from two L ligands and two N atoms from another two ligands. Each ligand bridges four Zn(II) centres, extending the structure into a three-dimensional polymer with a 4-connected (6(5),4(1)) topological structure containing two-dimensional homochiral layers constructed from one-dimensional metal-organic helices. Investigation of the thermal stability of the compound shows that the network has very high thermostability and is stable up to 720K.

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