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Wei S.,Anyang University, China | Wang S.,Anyang University, China | Zhang Y.,Henan University of Urban Construction | Zhou M.,Donghua University
Sensors and Actuators, B: Chemical | Year: 2014

Different morphologies of ZnO nanomaterials (long nanofibers, rod-like short nanofibers and nano-powders) were successfully synthesized by electrospinning process and chemical precipitation, respectively. A comparative ethanol sensing study among the three samples were also performed. The results indicate that the ZnO long nanofiber sensor shows desirable response to ethanol at 270 C with good stability, which is attributed to the long nanofiber structures. This sample also presents good selectivity and fast response-recovery properties (7-9 and 9-11 s, respectively). The ethanol sensing mechanism and the advantages of the long nanofiber structure in sensing materials were also discussed. © 2013 Elsevier B.V.


Jin H.X.,Zhejiang University | Chen H.Y.,Henan University of Urban Construction
Journal of Chemical and Engineering Data | Year: 2012

Densities for 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF 4)-glucose-water solutions were determined at 298.15 K. The measured densities were used to calculate the apparent molar volumes of glucose (V Φ,S) and [Bmim]BF 4 (V Φ,IL) in the studied solutions. Infinite dilution apparent molar volumes, V Φ,S ∞ and V Φ,IL ∞, have been evaluated, together with the standard transfer volumes of the sucrose (Δ tV S ∞) from water to aqueous solutions of [Bmim]BF 4 and those of [Bmim]BF 4 (Δ tV IL ∞) from water to aqueous glucose solution. It was shown that the Δ tV S ∞ and Δ tV IL ∞ values are positive and increase with increasing molalities of [Bmim]BF 4 and glucose, respectively, and the values of V Φ,S ∞ have the order of glucose < sucrose. The volumetric interaction parameters for [Bmim]BF 4-glucose pairs in water were also obtained and interpreted by the structural interactions model. © 2012 American Chemical Society.


Du L.,Henan University of Urban Construction | Lei Y.,Henan University of Urban Construction
Materials Letters | Year: 2013

High-quality Chlorine (Cl) doped CdSe nanobelts (NBs) with single-crystal wurtzite structure were synthesized by using CdCl2 as the dopant via a thermal co-evaporation method. The n-type conductivity of CdSe NBs was confirmed by field-effect transistors (FETs) based on single NBs. The electron concentration and mobility of these CdSe NBs are about 6.67×10 18 cm-3 and 17.4 cm2/Vs, respectively. High-performance nano-Schottky diodes on single CdSe NBs with Au Schottky contact electrodes have been fabricated and studied. The CdSe NB/Au Schottky diode show an excellent rectification characteristic with a rectification ratio up to 107 within ±1 V and small ideality factor of ∼1.2, which can also function as photodetectors with an ultrafast response speed of 26/50 μs, representing the best value obtained for the CdSe based nano-photodectecors. These results reveal that such CdSe NBs and their nanodevices have great potential for nano-electronic and optoelectronic applications. © 2013 Elsevier B.V.


Du L.,Henan University of Urban Construction | Lei Y.,Henan University of Urban Construction
Materials Letters | Year: 2012

High quality n-type CdSe nanobelts (NBs) were synthesized via the chemical vapor deposition (CVD) method in a Cd-enriched atmosphere. CdSe NB field-effect transistors (FETs) and CdSe NB/p-Si heterojunction devices were fabricated and studied. The n-type conductivity of CdSe NBs was confirmed by nanoFETs based on individual NBs. The heterojunction devices were constructed with the n-type CdSe NBs and p-type bulk Si with 100 nm thickness SiO 2. Typically, the heterojunction device exhibits an excellent rectifying behavior in the dark with a rectification ratio greater than 10 3 within ±3 V, and photovoltaic effect with an open-circuit photovoltage (V OC) of about 0.67 V, a short circuit current (I SC) of about 5.88 nA, and an energy conversion efficiency of 1.41%, and shows excellent environmental stability when placed in air for more than 3 months. This study demonstrates a convenient and low-cost method to construct CdSe NBs/Si heterojunction devices, which can be extended to the study of other semiconductor nanomaterials. It is expected that the heterojunction devices will have a great potential for future applications of optoelectronic integration. © 2011 Elsevier B.V. All rights reserved.


Wang N.,Henan University of Urban Construction
Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry | Year: 2011

The reaction of [VO(acac)2] with 3-methyl-N'-[1-(2- hydroxynaphthyl)ethylidene]benzohydrazide (H2L1) and 3-methyl-N'-[(2-hydroxy-1-naphthyl)methylidene]benzohydrazide (H 2L2), respectively, in methanol affords two new oxovanadium(V) complexes, [VO(OMe)L1]2 (1) and [VO(OMe)(HOMe)L2] (2). Both complexes have been characterized by elemental analysis, I.R., and single crystal X-ray diffraction methods. Complex (1) is a methoxide-bridged dinuclear oxovanadium(V) compound, while complex (2) is a mononuclear oxovanadium(V) compound. The dinegative hydrazone ligands coordinate to the metal atoms through phenolate, imine, and deprotonated amine donor atoms. The geometry around each vanadium atom is a distorted VNO5 octahedron in both complexes. Copyright © Taylor & Francis Group, LLC.


Li L.,Henan University of Urban Construction
International Journal of Digital Content Technology and its Applications | Year: 2012

Though real estate companies had received the great achievement, it was involved in headed market in China, there are still many shortcomings. In our country, the real estate companies had no scale and competence advantage, lack technology and service innovation. Now, China has entered the stage of quickened urbanization process. There are many great foreign companies in our real estate market which competed with us and company brand had become very important. In this paper, we shall investigate the dynamic multiple attribute decision making (DMADM) problems for evaluating the real estate enterprise competitiveness with linguistic information. We utilize the dynamic linguistic weighted geometric (DLWG) operator and linguistic weighted geometric (LWG) operator to aggregate the linguistic information corresponding to each alternative and get the overall value of real estate enterprise competitiveness, then rank the cities with linguistic information and select the most desirable one(s) by using the overall value of real estate enterprise competitiveness Finally, an illustrative example for evaluating the real estate enterprise competitiveness is given to verify the developed approach and to demonstrate its practicality and effectiveness.


Wu X.,Henan University of Urban Construction
International Journal of Digital Content Technology and its Applications | Year: 2012

The mainstream of the development of fuzzy mathematics is in its applications. Due to the ambiguity of the concept has found a description of the fuzzy sets, the use of the concept of judgment, evaluation, reasoning, decision making. The terms of the contract selection of the project after the tender offer, agreed by the A side and B side. The engineering contract management, industrial and commercial administrative organs, it is the administrative department of construction and financial institutions, as well as owners, contractors. The paper presents the contract and project quality management system based on fuzzy mathematics methods.


Wang B.,Henan University of Urban Construction
Chinese Journal of Mechanical Engineering (English Edition) | Year: 2010

As two independent problems, scheduling for parts fabrication line and sequencing for mixed-model assembly line have been addressed respectively by many researchers. However, these two problems should be considered simultaneously to improve the efficiency of the whole fabrication/assembly systems. By far, little research effort is devoted to sequencing problems for mixed-model fabrication/assembly systems. This paper is concerned about the sequencing problems in pull production systems which are composed of one mixed-model assembly line with limited intermediate buffers and two flexible parts fabrication flow lines with identical parallel machines and limited intermediate buffers. Two objectives are considered simultaneously: minimizing the total variation in parts consumption in the assembly line and minimizing the total makespan cost in the fabrication/assembly system. The integrated optimization framework, mathematical models and the method to construct the complete schedules for the fabrication lines according to the production sequences for the first stage in fabrication lines are presented. Since the above problems are non-deterministic polynomial-hard(NP-hard), a modified multi-objective genetic algorithm is proposed for solving the models, in which a method to generate the production sequences for the fabrication lines from the production sequences for the assembly line and a method to generate the initial population are put forward, new selection, crossover and mutation operators are designed, and Pareto ranking method and sharing function method are employed to evaluate the individuals' fitness. The feasibility and efficiency of the multi-objective genetic algorithm is shown by computational comparison with a multi-objective simulated annealing algorithm. The sequencing problems for mixed-model production systems can be solved effectively by the proposed modified multi-objective genetic algorithm. © 2010 Chinese Journal of Mechanical Engineering.


Jin H.X.,Zhejiang University | Chen H.Y.,Henan University of Urban Construction
Journal of Chemical and Engineering Data | Year: 2011

Densities for 1-allyl-3-methylimidazolium chloride ([Amim]Cl)-sucrose-water solutions were measured at 298.15 K. These data were used to calculate the apparent molar volumes of sucrose (V φ,S) and [Amim]Cl (V φ,IL) in the studied solutions. Infinite dilution apparent molar volumes, V φ,S 0 and V φ,IL 0, were also obtained, together with the standard transfer volumes of the sucrose (Δ tV S 0) from water to aqueous solutions of [Amim]Cl and those of [Amim]Cl (Δ tV IL 0) from water to aqueous sucrose solution. Additionally, the system studied here was compared with 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF 4)-sucrose-water mixture. It was shown that the Δ tV S 0 and Δ tV IL 0 values are positive and increase with increasing molalities of ILs and sucrose, respectively, and the Δ tV S 0 and Δ tV IL 0 values have the order of [Amim]Cl > [Bmim]BF 4. Additionally, the volumetric interaction parameters for ionic liquid (IL)-sucrose pairs in water were also obtained and interpreted by the structural interactions model. © 2011 American Chemical Society.


Qiuhong L.,Henan University of Urban Construction
Information Technology Journal | Year: 2013

Grey Neural Network is an innovative intelligent computing approach combing grey system model and neural net-work, which makes full use of the similarities and complementarities between grey system model and neural network to settle the disadvantage of applying grey model and Neural Network separately. Therefore, the Grey Neural Network model can be applied practically in a wide range. Coal is basic energy in China and it supports the rapid development of the national economy. Therefore the forecast of coal demand is particularly important for the rational use of coal resources and the sound development of China economy. In recent years, there are some limitations of the demand for coal forecast. The three layers grey neural network model is established based on Matlab technology and to be simulated in this study. After actual data testing, the coal demand is forecasted with the methods. ©2013 Asian Network for Scientific Information.

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