2018 Vol. 33, No. 1
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Under the culture temperature 35℃,shaking frequency 150 r/min,culture pH value 7.0 and culture time 72 h,the quantity of lycopene-degrading reached 224.4 mg/L by Bacillus cereus strain L16 with 300 mg/L lycopene in the medium.The degradation products analyzed by GC-MS were 6-methyl-5-hepten-2-one and isopropyl ketone,which were the characteristic aromatic components for tobacco.
The selected ion monitoring (SIM) was used as the mass spectrum signal acquisition mode. UsingHP-5MS capillary column, a method for determination of ten compounds in clary sage (Salvia sclarea L.) oil has been developed.Odor threshold values of ten compounds were determined,and odor active values were obtained.The results showed that:Benzyl alcohol was used as an internal standard.The samples were separated on a DB-5 capillary column.The selected ion monitoring (SIM) was used as the mass spectrum signal acquisition mode.The components of the sample were well separated in the experimental conditions above,and had good linearity with the correlation coefficients higher than 0.999.The average recoveries were in the range of 90.6%~97.2%.The limits of detection (S/N ≥ 10) were in the range of 9.5~232.8 ng/L, which illustrated the good repetability and sensibility of the method.The compounds in clary sage oil with high odor active value were linaloolwith the content of 20.3% and linalyl acetate with the content of 42.7%.
The classification and hazard of HAAs, the detection of heterocyclic aromatic amines (HAAs)in cigarette smoke, the metabolism research progress of main HAAs and monitoring methods of human exposure were reviewed.It was pointed out that HAAs were highly carcinogenic and mutagenic. There are ten main HAAs in cigarette smoke, and the higher contents are Harman,Norharman,AαC and MeAαC. Studies of major heterocyclic amines in cigarette smoke are mostly focused on AαC and MeAαC. The metabolic pathways of AαC and MeAαC have been clarified, but there is a slight difference in the literature regarding the amount of their metabolites. The exposure monitoring of HAAs is mainly achieved through the detection of prototype HAAs in human urine or hair, metabolites of HAAs can be used as exposure markers for monitoring the exposure of HAAs. Future research will focus on the synergistic mutagenesis of Harman and Norharman, metabolites of AαC and MeAαC as exposure markers, rapid and effective detection method to determine HAAs in biological sample and the correlation between smoking and the exposure of HAAs to further reduce the harmfulness of HAAs and provide references for the study of "smoking and health".
This study aim to explored the preparation and purification technologies of taurine from the cooking liquid of Ruditapes philippinarum using enzymatic hydrolysis. The results showed that the alkaline protease was the optimum enzyme for extracting taurine. Under the conditions of enzymolysis temperature 45℃, enzymolysis time 3.5 h and enzymolysis pH=8.0, the purity and recovery of taurine reached 8.67% and 95.80%, respectively. After removing salt using electrodialysis, the purity and recovery of taurine reached 21.30% and 89.59%, respectively. After elution on cation exchange resin, the purity and recovery of taurine reached 31.18% and 83.64%, respectively. After the ethanol recrystallization, the purity of taurine reached 97.28%.
The recent research and application status of chilling methods of post-mortem carcass was summarized,including the conventional chilling, spray chilling, vascular perfusion chilling, stepwise chilling and very fast chilling. Optimizing the chilling methods of post-mortem carcass in order to reduce weight loss of post-mortem carcass, improving the meat tenderness, ensuring meat quality and decreasing economic loss of meat factory have become the research hotspot in this field. Exploring the effect of stepwise chilling and very fast chilling on meat tenderness and potential mechanism,comprehensively considering the differences in carcass types and muscle fibers according to mass and shape of post-mortem carcass, adjusting the parameters of different chilling methods, applying the electrical stimulation and improving the packaging methods to guarantee the meat quality and safety will be the development trend and main research direction in the future.
With phthalonitrile,graphene oxide(GO) as raw material,triazine-linked covalent organic framework/graphene composite was synthesized by a simple ion thermal method.As supercapacitor electrode material,the electrochemical performance of the CTFs/G composites was analyzed by electrochemical workstation. The results showed that the CTFs/G composites had good rate capability and excellent electrochemical performance.The composites displayed specific capacitance of 372 F/g at current density of 0.2 A/g,which is much higher than that of pure CTFs (166 F/g).It could be remained at 168 F/g after 1000 cycles,and the cycle stablity was good.
DTPA, EDTA and HCl extractants were used to extract heavy metal absorbable mercury in the soil, by comparison,the highest extraction rate of the extractant DTPA was chosen. Then, the hollow carbon nanospheres/polyaniline composite was prepared. The composite was made into a DNA-modified hollow carbon nanospheres/polyaniline electrochemical sensor and the absorbable mercury in the soil was detected. The results showed that DTPA had the highest extraction rate of absorbable mercury in the soil from 20% to 31%. And the chemical sensor could detect the absorbable mercury content in soil accurately and sensitively. Compared with the results of atomic fluorescence spectrometry, the relative errors between the two actual samples were 2.32% and 2.71%, respectively.
Based on the formation mode of white light gel, the research status of constructing white light gel with non-covalent interactions such as hydrogen bonding, π-π stacking and metal complexing was reviewed. It was pointed out that the non-covalent bonding of white light gel could make different chromophore compounds produce a dynamic and reversible one-dimensional assembly, self-assembly of aggregates could help regulate the distance between donor and acceptor molecules and dipole direction to improve the energy transfer efficiency between molecules to obtain a tunable white light gel material.This white light gel had obvious stimulus response characteristics and flexible phase transition to the outside world as well as good plastic workability, and had great potential applications in the fields of display materials, lighting equipment and the like prospect. However, the existing white light gel system had the problems of being destroyed under strong mechanical or high temperature, low gel strength and long preparation period of the dry gel. In the future,the structure-activity relationship research between the gel factor structure and the donor and acceptor energy transfer efficiency should be strengthened to promote the industrialization application of white gel as soon as possible.
As most ownership transfer protocols of RFID tags were subject to no independence of the original owner and security privacy issues,the RFID tags ownership dynamic transfer protocol of multi-owner with trusted third party (TTP) weights was proposed based on Lagrange polynomial interpolation algorithm.In the protocol,the new owner would obtain the original subkey and weight from the original owner in the way of purchasing,the legality of the original owner and the new owner were verified by recovering the original key and TTP,and the subkey was distributed according to the weight of the new owner by using the secrete sharing scheme.The simulation result showed that the protocol significantly improved the security of ownership transfer,and the calculation quantity and time-consuming were within the acceptable scope,which was applicable to the low cost tag.
For the problems of brightness elevation model shadow removal algorithm GSR,such as the manual setting of key parameters and the defect in the division of the equal brightness regions and the luminance compensation method,an road shadow emoval algorithm SGRSR based on the adaptive brightness elevation model was proposed.Firstly,the influence of pavement crack and pavement texture for the division of the shadow region was eliminated by using morphological dilate operation and Gaussian smoothing filter.Secondly,the maximum entropy threshold segmentation algorithm was used to calculate the partition threshold value of the shaded area and the non-shaded area of the image after Gaussian smoothing.By this way,the threshold was determined automatically.Finally,the pavement shadow was eliminated by using the improvement of the equal brightness region partition model and the luminance compensation method.Experimental results showed that the SGRSA algorithm could eliminate the shadow of the pavement image automatically and had the more natural transition in the brightness of the pavement image compared with the GSR algorithm.
In view of the defects of traditional forensic human body injury area measurement method such as long time consuming and poor clustering effect and so on,an image segmentation algorithm named SLIC-AFSA-FCM was proposed based on the optimized fuzzy C-means (FCM) algorithm to measure the forensic human body injury area.The algorithm used super-pixel technology to reduce the pixel sample size of the image to be processed,preprocessed the pixel sample set using a multi-subgroup parallel artificial fish swarm algorithm (MSSP_AFSA) to calculates the optimal image segmentation initial cluster center,and used the FCM algorithm to perform image segmentation of cluster classification.The experimental results showed that the improved algorithm could greatly improve the speed and area estimation accuracy of human body injury images compared with K-means and FCM algorithms.
High speed digital camera was used to record eletrohydrodynamics spraying modes of multi-capillary with ethanol. The spraying modes of multi-capillary were obtained by analyzing the pictures, and the effect of operating parameters on electro-spraying modes was discussed. The spraying modes with two configurations were classified by the dimensionless parameter flow (α) and electric Bond number (β). The experimental results indicated that similar to spraying mode of mono-capillary,dripping, spindle, jet and multi-jet modes could be observed in spraying mode of multi-capillary. The modes could transits from one mode to another with varying applied voltage and flow rate. The two jets from double-capillary showed symmetrical skewed distribution due to Coulomb repulsive forces between them. Although there are different configurations for two kinds of capillaries, the spindle and pulsated jet modes could be observed. For these two modes, the frequency of spindle and pulsated jet ejected from the capillary would also increased and the swing range of the spindle and jet would reduce with an increase in electric Bond number. The transition from spindle to pulsated jet mode would be observed at a critical electric Bond number. With electric Bond number further increased, the multi-jet mode would be observed for two configurations. The number of jet increased with an increase in electrical Bond number.
The exact travelling wave solutions of the famous Mikhailov-Shabat-Sokolov (MSS) equation,which contained three kinds of forms,such as the solution of hyperbolic functions,the solution of trigonometric functions and the solution of rational functions,were obtained by using the ((G')/G) expansion method.Especially when the parameters were taken as special values,the solution of the hyperbolic functions could be transformed into the soliton wave solutions.
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
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