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Zhao W.X.,Shaanxi Normal University | Zhao W.X.,Ningxia Teachers University | Wang Z.L.,Shaanxi Normal University
Transactions of the Institute of Metal Finishing | Year: 2013

The adhesion strength between acrylonitrile-butadiene-styrene (ABS) resin and electroless copper can be improved significantly by a low environmental pollution etching system containing H2SO4-MnO 2-Na4P2O7-H2O colloid as a replacement for conventional chromic acid etching solutions. In this paper, the effects of the H2SO4 concentration and Na 4P2O7 content on the surface topography, surface roughness and the adhesion strength were studied. When the H 2SO4 concentration was 12·9M, good etching performance was obtained. The average adhesion strength between the electroless copper and ABS substrate reached 1·30 kN m-1. The surface contact angle measurement indicated that the ABS surface became hydrophilic and the contact angle decreased from 92·1 to 31·2°. © 2013 Institute of Metal Finishing.


Zhao W.,Shaanxi Normal University | Zhao W.,Ningxia Teachers University | Wang Z.,Shaanxi Normal University
International Journal of Adhesion and Adhesives | Year: 2013

A low environmental pollution etching system, MnO2-H 2SO4-H3PO4-H2O colloid, was used to investigate surface etching performance of polycarbonate (PC) as a replacement for the chromic acid etching solution. The effects of H 2SO4 concentrations, H3PO4 concentrations and etching times upon the surface topography, surface chemistry and surface roughness were studied. With the appropriate etching treatment, the surface average roughness (Ra) of PC substrates increased from 3 to 177 nm, and the adhesion strength between the electroless copper and PC substrate also reached 1.10 KN m-1. After the etching treatment, the PC surface became hydrophilic and the surface contact angle decreased from 95.2° to 24.8°. The intensity of C-O groups increased and the new functional groups (-COOH) formed on the PC surface with the etching treatment, which improved the adhesion strength between PC substrate and elctroless copper film. © 2012 Elsevier Ltd. All rights reserved.


Xu L.,Ningxia Teachers University | Cheng L.,Ningxia Teachers University
Journal of Nanomaterials | Year: 2013

We present a Raman-based study on the graphite oxide under high pressure. The graphite oxide is stable under hydrostatic high pressure ambient. By carefully fitting the D, G, and D′ bands which are merged at some extent, we successfully retrieve the information of peak position evolution of G band of graphite oxide under pressure, and it is found that the G band pressure coefficient is very close to that of graphene, and the pressure-induced peak position shift is reversible upon releasing the pressure. The Raman-based high pressure investigation indicates that the graphite oxide possesses good mechanical ductility despite the fact that it is oxygenated by functional groups. This study provides useful fundamental understanding of graphite oxide. © 2013 Lianqiang Xu and Li Cheng.


Yongfeng L.,Ningxia Teachers University
Lecture Notes in Electrical Engineering | Year: 2013

pH is a widely-used concept and physical quantity in chemistry and related disciplines. However, many studies found that this concept has numerous shortcomings. For instance, in the theoretical world, no consistent definition has been given to it; its concepts are disorderly characterized without theoretical significance; its physical significance also is not undefined and has no universality; in the practical application, the concepts of pH reference, pH standard and pH scale all are highly unclear, and pH is impacted by the temperature, concentration and pressure of solutions as well. This paper proposes to use AG to measure the acidity or basicity of solutions and proves this method can overcome all the shortcomings of pH through theoretical derivation and experiment, further showing that using AG to measure the acidity or basicity of solutions is scientific in theories and feasible in practices, and also owns its advantages. © 2013 Springer-Verlag.


Xu L.,Ningxia Teachers University | Cheng L.,Ningxia Teachers University
Materials Characterization | Year: 2010

Single-crystalline K2Ti6O13 nanoribbons with typical width ranging from one hundred nanometers to a few hundred nanometers and length up to tens of microns were prepared from KCl flux. The nanoribbons were characterized by a range of methods including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, selected area electron diffraction and high-resolution transmission electron microscopy. Ultraviolet-visible experiments showed that the K2Ti6O13 nanoribbons were wide-band semiconductors with a band width Eg = 3.4 eV. The mechanism of one-dimensional growth of the nanoribbons was attributed to the oriented attachment mechanism. © 2009 Elsevier Inc. All rights reserved.


Liang Y.,Ningxia Teachers University
Engineering Technology, Engineering Education and Engineering Management - International Conference on Engineering Technology, Engineering Education and Engineering Management, ETEEEM 2014 | Year: 2015

With rutin standard sample as the comparison, flavonoid extraction rate as an indicator, UV-2450 ultraviolet visible light spectrophotometer to measure flavonoid content in planted Trollius chinensis through orthogonal experiment, this experiment optimizes process condition of flavonoid in Trollius chinensis through water extraction and ethanol extraction. The result shows that the flavonoid extraction rate of T rollius chinensis through ethanol extraction method is obviously higher than water extraction, and the optimal extraction process condition is: ethanol concentration is 75%, extraction time is 90 min, extraction times are 3, and fluid material ratio is 20:1. © 2015 Taylor & Francis Group, London.


Liang Y.,Ningxia Teachers University
Engineering Technology, Engineering Education and Engineering Management - International Conference on Engineering Technology, Engineering Education and Engineering Management, ETEEEM 2014 | Year: 2015

This article adopts the method of orthogonal experiment to study the process of total flavonoid in Trollius chinensis through ultrasonic wave-assisted extraction, microwave-assisted extraction and backflow extraction. Based on the simulation results, among these three methods of planted Trollius chinensis, in terms of flavonoid compound extraction efficiency, microwave extraction method is better than ultrasonic radiation extraction method, which is better than backflow extraction method. © 2015 Taylor & Francis Group, London.


Ma F.,Ningxia Teachers University | Zhao H.,Ningxia Teachers University
Chinese Journal of Chemical Engineering | Year: 2013

Mesoporous zirconia was synthesized by a new and simple method. Zirconium n-propoxide was used as the zirconium source. A small, inexpensive nonsurfactant, triethanolamine, was used as the template. The template was removed by thermal treatment in air and supercritical fluid extraction using CO2. The structure of the resulting materials was characterized by X-ray diffraction, transmission electron microscopy, and N2 adsorption-desorption analyses. The materials are found to have narrowly distributed average pore diameters and wormhole-like pore channels. However, higher surface area and larger pore volume are exhibited after supercritical fluid extraction with CO2. The removal of the template by thermal treatment also leads to condensation and mild shrinkage of the zirconia framework. © 2013 Chemical Industry and Engineering Society of China (CIESC) and Chemical Industry Press (CIP).


Guan L.,Ningxia Teachers University
Natural Product Research | Year: 2012

A native polysaccharide (MCP2) was extracted and isolated from Momordica charantia. Four sulphated derivatives of MCP2 were prepared by chlorosulphonic acid method. The structures of the sulphated derivatives were characterised by FT-IR spectra. Depending on the reaction conditions, the sulphated derivatives showed different degree of substitution (DS) ranging from 0.56 to 1.10, and different weight-average molecular mass (Mw) ranging from 7.2 to 9.3KDa. It implied the efficient substitution of hydroxyl groups in the polysaccharides by sulphated groups with degradation. The effects of the sulphated derivatives on inhibiting the growth of HepG2 cells and Hela cells invitro were compared with taking non-modified MCP2 as control. The sulphated derivatives inhibited the growth of HepG2 cells and Hela cells invitro significantly, which indicated that sulphated modification could enhance the anti-tumour activity of MCP2. © 2012 Copyright Taylor and Francis Group, LLC.


Zhao X.,Ningxia Teachers University
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2013

The automatically-controlled spatial energy distributions of the electron beam, used to evaporate materials in the lab-built, optical film reactor, were physically modeled, empirically approximated, and numerically calculated to improve the uniformity of the energy distribution of the electron beam. The dedicated software was developed based on the calculated results, to improve the control precision by compensating the magnetic field with the electric field, to significantly better the uniformity of the spatial energy distribution of the electron beam, and to avoid over-evaporating some spots of the source. The test results show that without modification of the hardware of the control unit, the newly-developed control software considerably improves the uniformity, compactness, and flatness of the optical thin films, deposited by electron beam evaporation.

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