2016 Vol. 31, No. 3
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With zinc acetate and urea as raw materials, the porous single crystalline ZnO nanoplates were prepared by hydrothermal method combined with the heat treatment process.The Au nanoparticles were synthesized by the citric acid reduction method.Then, polyethylenimine (PEI) was used to modify the porous single crystalline ZnO nanoplates followed by anchoring Au nanoparticles (NPs) on their surface through electrostatic interactions.The as-prepared products were characterized by X-ray diffraction (XRD),scanning electron microscopy (FE-SEM) and energy dispersive spectrum (EDS).The porous ZnO nanostructures and the successful modification of Au nanoparticles were observed.The gas sensitivity experiment showed the as-prepared products exhibited the remarkable selectivity to formaldehyde,the best working temperature was 300℃ and a favorable linear response range was 10~500×10-6.
Fe3O4@SiO2@MIL-101(Cr) magnetic porous hybrids were prepared via physical method.The structure and morphology of the resulted samples were characterized by transmission electron microscopy (TEM),X-ray diffraction (XRD), thermogravimetric analysis (TG) and infrared (IR). Through UV absorption spectrum,the influence of adsorption time, concentration of bisphenol A (BPA), and the amounts of Fe3O4@SiO2@MIL-101(Cr).the asorption ability of Fe3O4@SiO2@MIL-101(Cr) for BPA was studied.The results showed that the adsorption ability increased with increasing contact time and the equilibrium was established within 150 min. When the concentration of BPA was 80 mg/L and the amount of magnetic porous materials was 1 mg, the maximum absorption amount was 101.4 mg/g.
The 3D graphene was prepared by redox mothod and then was functionalized by amino-modified (G-NH2). The single-stranded DNA could immobilize onto the surface of the fabricated biosensor via the electro-static interaction between DNA and G-NH2 and coordination with the relative heavy metal ions (Ag+,Hg2+,Cu2+).The surface morphology was determined using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Atom force microscopy (AFM) and X-ray photoelectrons spectroscopy (XPS) were applied to measure the chemical structure and componenets of the fabricated G-NH2 before and after being immobilized DNA.The results showed that the surface of 3D G-NH2 was smooth. Signal changes of XPS peak demonstrated that DNA were immobilize onto the surface of 3D G-NH2. The electrochemical impedance spectrum was used to characterize the electrochemical perforamance of the biosensor during the procedure of the detection of heavy metal ions. It explored that the Rct values were changed significantly after DNA was immoloilized onto the surface of 3D G-NH2 and then coordinated with the relative heavy metal ions.This study demonstrated this kind of biosensor could be used to adsorb biomolecules and detect the co-exist system of many heavy metal ions.
Covalent organic frameworks (COFs) is an emerging type of crystalline porous material, which includes four types-boron type, imine type, triazine type and other type. In comparison with traditional amorphous porous materials,COFs shows exceptional thermal stability,low density,high specific surface area and flexible structure modification, which made it have wide potential application in gas adsorption,photoelectricity, catalysis and biosensor. In addition to designing and developing new precursor, new synthetic methods and new ways of connection to achieve the perfect combination of theory and experiment,the addition of a specific block to give the material a wider range of application performance will be the development direction of the COFs composite materials in the future.
The antifungal activity of GBP against Penicillium sp. and Aspergillus was evaluated. The results showed that GBP had strong antifungal activity against the two tested fungi. The antifungal activities increased with the increase of GBP concentration. Moreover, GBP could directly inhibit the mycelial growth and spore germination. The inhibitory effect of GBP against Penicillium sp. and Aspergillus increased with increasing concentration of GBP. The obvious increase in electric conductivity of hyphae suspension indicated that GBP could increase the membrane permeability of Penicillium sp. and Aspergillus. Therefore, GBP could serve as a natural preservative used in food preservation.
Visum ardiculatum was extracted by water bath and ultrasonic, and its four fractions of chloroform, ethyl acetate, n-butanol, and water were prepared. The free-amino acid, total polyphenol, tea polysaccharides and flavonoids contents Visum ardiculatum were determined. So were the scavenging effects of different parts of Visum ardiculatum on DPPH radical, ABTS radical, superoxide anion and hydroxyl radical and FRAP value. The results showed that the antioxidant activity of Visum ardiculatum in vitro was potent. The scavenging effects of all the fractions on ABTS radical reached 98% and that of DPPH radical reached 88%. The synthetical value calculated by fuzzy assessment was respective of the 5 antioxidant assays.The highest was 4.66 of water extracts by water bath, the lowest was 0.21 of chloroform fraction. It was largely due to the total polyphenol (P<0.05) and flavonoids contents (P<0.05).The content of tea polysaccharides reached 5 468.08 mg/100 g.
Foodborne pathogenic bacteria is the hidden danger of food safety.During many detection methods,PCR and PCR-derived technologies have advantages of sensible,specific,convenient and rapid,which have been widely used in the detection of foodborne pathogenic bacteria.At present,PCR detection technologies including multiple PCR,real-time PCR,multiple real-time PCR,IMS-multiplex real-time PCR,PCR-ELISA,EMA/PMA-PCR and DPO-PCR have defects such as high cost,low efficiency and poor quality control and need to be impoved to meet the requirements of high sensibility,high specificity,high throughput,high reproducibility,convenience and economics for the detection of foodborne pathogenic bacteria.
For CNC Swiss type machine tool, conventional guide sleeve mechanism can not eliminate the gap between the guide sleeve and the bar material which is caused by the diameter tolerance of the bar material in real time, and brings problem of bending deformation of machining workpiece. The research came up with a kind of adaptive synchronous rotary guide mechanism in optimization design:By ABAQUS software, the research established finite element model about spring collect and simulation and obtained polynomial fitting curve. Then fitting curve was combined with the Fmincon optimization algorithm in Matlab to determine the structure parameters of the disc spring. Compare to conventional guide sleeve, the deflection of the workpiece was reduced by 35.71%.
In order to identify the elements of complex equipment service process and its positions and roles,a business process modeling method of complex equipment based on Petri nets in service life cycle was presented. The time interval boundary was defined and the three-stage division of services business including early, middle and end stage was finished. Then, in analysis of the common elements of service business, and business activity relationship models and modeling steps based on Petri nets were given. Finally, taking the modeling of the large vertical mill of ore class manufacturing enterprises as an example, the proposed method was verified by using reachability graph. The research could provide decision-making support for the service business process optimization of complex equipment.
The length, width and depth of insertion head of micro-channel heat exchanger were selected as investigation factors,then models were set up by using uniform design method, and sensitivity parameters that affected the uniform distribution of the micro-channel heat exchanger fluid flow were analyzed. The results showed that:1) Micro-channel heat exchanger fluid distribution uniformity was not only associated with the state of the fluid flow, but also related to the structure and geometry; so keeping the lower flow rate (0.05~0.10 m/s) of the fluid micro-channel could be better for distribution uniformity. 2) In the case that the inlet flow was constant, fluid flow distribution uniformity was the combined effect of the manifold results of the channel length, width, and the collecting pipe insertion depth. The factors affecting the fluid distribution uniformity in a descending order were the width of the micro-channel, the head insertion depth of micro-channel and the length of the micro-channel.
For public building sub metering in energy resolution of problems, the improved SA_PSO algorithm was put forward. The algorithm simulated the combination of annealing mechanism and particle swarm optimization algorithm, introduced particle velocity shrinkage factor and the optimal particle roulette gambling strategies for perturbation. Using SA_PSO algorithm to optimize the public building energy resolution mathematical model parameters, the hourly energy consumption data from split could be gotten. The simulation results showed that SA_PSO algorithm had better convergence performance, could effectively avoid the particles falling into local minimum energy consumption parameters correction value and quickly reached the global optimum.
Aimed at the problem that the standard PSO algorithm was very sensitive to fall into the phenomenon of local minima and couldn't escape,a new fast convergence PSO (FCPSO) algorithm based on balancing the diversity of location of individual particle was proposed. The algorithm introduced a new parameter, namely particle mean dimension was used to locate the global optimum solution fast and accurately. The experiment results showed that the convergence of the FCPSO algorithm was better than PSO algorithm and CPSO algorithm.
In order to solve the P2P underlying network topology mismatch problem based on JXTA platform, which caused the lower transmission efficiency in the process of message transmission, severe waste of network resources, a statistical vector algorithm called JPDV (JXTA Rendezvous Peer-routing Algorithm Based on Delay Statistics Vector) based on the Peer's RPV (Rendezvous Peer-routing View) of JXTA was proposed. Node chose rendezvous with good creditworthiness and high capability as Landmarks node, and constructed delay statistics vector and got its distance by measured delay to Landmarks node, and then compared distance with old logical neighbor, modified its routing table with less distance. As the more near route path was chosen on communication to other peers, JPDV had better matching with the underlying network topology. Simulation experiment results showed that JPDV algorithm had the rationality and validity, which reduced the length of the peer link and improved the retrieval efficiency.
To on-line monitor the temperature distribution of the fiber compounded cable, the spontaneous Brillouin scattering of single-mode fiber was applied to construct a Brillouin optical time domain reflectometry (BOTDR). With the BOTDR sensing system, the central frequency of every spatial resolution wasabstracted; then the Brillouin frequency distribution along the sensing fiber was obtained; finally the temperature distribution along the fiber was calculated. Compared to the experimental results of thermo-pairs, the temperature difference was less than 2℃; but the BOTDR sensing system was a better scheme for temperature monitoring of long-distance compounded cable.
La2Hf2O7 gate dielectric films with high dielectric constants have been grown on silicon (100) substrates by pulsed laser deposition.The structure of the films and the interface layer were studied by using X-ray diffraction (XRD), synchrotron X-ray reflectivity (XRR), and X-ray photoelectron spectroscopy (XPS). X-ray diffraction demonstrated that the as-grown films were amorphous and crystallized into La2Hf2O7 thin films after 1 000℃ annealing. Silicon oxide and silicate interlayer were observed between the Si substrate and as-grown film. The composition and thickness of the interlayer greatly depended on the grown condition, and annealing could effectively eliminate SiOx formation and improve the dielectric property of La2Hf2O7 gate dielectric films.
Founded in 1986, bimonthly
Administered by:The Education Department Henan Province
Sponsored by:Zhengzhou University of Light Industry
Editor-in-chief:Wei Shizhong
Executive Editor-in-Chief:Zou Lin
Deputy Editor-in-Chief:Qu Shuanghong
Edited & published by:Editorial Department of Journal of Light Industry
CN 41-1437/TS
ISSN 2096-1553
Address:136 Science Avenue, Zhengzhou City, Henan Province, China
Postal Code:450001
Tel:(086)0371-86608635
(086)0371-86608633