2013 Vol. 28, No. 1
Display Method: |
2013, 28(1)
:1-6,15.
doi: 10.3969/j.issn.2095-476X.2013.01.001
Abstract:
Biochip, due to the advantages of multiplexed, high throughput screening, high sensitivity, minimal amount for samples and fast detecting ability, makes it a good potential in food safety field. its applications widely in food monitoring field, such as food-borne pathogen detection, food toxicology, food nutriology, genetically modified food and pesticides residue determination etc.Biochip technology have broad prospects and also have many problems to solve,and pointed out that the trend for biochip would be in the directions of miniaturization, integration, informatization and industrialization.
Biochip, due to the advantages of multiplexed, high throughput screening, high sensitivity, minimal amount for samples and fast detecting ability, makes it a good potential in food safety field. its applications widely in food monitoring field, such as food-borne pathogen detection, food toxicology, food nutriology, genetically modified food and pesticides residue determination etc.Biochip technology have broad prospects and also have many problems to solve,and pointed out that the trend for biochip would be in the directions of miniaturization, integration, informatization and industrialization.
2013, 28(1)
:7-10.
doi: 10.3969/j.issn.2095-476X.2013.01.002
Abstract:
The engineered strain of Escherichia coli with valine-pyruvate transaminase gene was constructed and the expression condition for valine-pyruvate transaminase was optimized.The result of PCR showed that a special DNA band was amplified and the length of the band was accord with the length of avtA,1 254 bp.Activity of valine-pyruvate transaminase was found by paper chromatography but the enzyme activity was not high.The expression of valine-pyruvate transaminase was evaluated by SDS-PAGE and a high expression was displayed.The optimal conditions were peptone 12 g/L,IPTG 0.4 mmol/L and induced time 8 h.
The engineered strain of Escherichia coli with valine-pyruvate transaminase gene was constructed and the expression condition for valine-pyruvate transaminase was optimized.The result of PCR showed that a special DNA band was amplified and the length of the band was accord with the length of avtA,1 254 bp.Activity of valine-pyruvate transaminase was found by paper chromatography but the enzyme activity was not high.The expression of valine-pyruvate transaminase was evaluated by SDS-PAGE and a high expression was displayed.The optimal conditions were peptone 12 g/L,IPTG 0.4 mmol/L and induced time 8 h.
2013, 28(1)
:11-15.
doi: 10.3969/j.issn.2095-476X.2013.01.003
Abstract:
The liquid medium and culture conditions of portabella mushroom(Agaricus brunnescens) SB65 strain were optimized by single-factor experiments and uniform design.The optimized medium were as follows(w/v):sucrose 5.5%,yeast extract 1%,MgSO4·7H2O 0.05%,KH2PO4 1%,NaCl 0.714 7%,CaCl2·2H2O 1% and the optimized culture conditions were as follows:initial pH=7.2,culture temperature 28℃,culture period 12 d,rotation rate 160 r/min,medium volume 50 mL per 250 mL flask and seed volume 8% (v/v).Under the optimized medium and culture conditions,the biomass of tested strain was 4.579 g/L.
The liquid medium and culture conditions of portabella mushroom(Agaricus brunnescens) SB65 strain were optimized by single-factor experiments and uniform design.The optimized medium were as follows(w/v):sucrose 5.5%,yeast extract 1%,MgSO4·7H2O 0.05%,KH2PO4 1%,NaCl 0.714 7%,CaCl2·2H2O 1% and the optimized culture conditions were as follows:initial pH=7.2,culture temperature 28℃,culture period 12 d,rotation rate 160 r/min,medium volume 50 mL per 250 mL flask and seed volume 8% (v/v).Under the optimized medium and culture conditions,the biomass of tested strain was 4.579 g/L.
2013, 28(1)
:16-19,29.
doi: 10.3969/j.issn.2095-476X.2013.01.004
Abstract:
Using anhydrous ethanol as extracting solvent,the technique of ultrasonic assisted extraction of black rice anthocyanins and its antioxidation were investigated.The results showed that the optimum extraction codition were temperature 50℃,ethanol volume fraction 35%,feed liquid ratio of 1:4,extracting time for 30 min.And comparison with no ultrasonic assisted extraction,ultrasonic assisted extraction black rice anthocyanins when ultrasonic power is 90 W,ultrasonic extraction time is 4 min,its antioxidation is the largest,so the ultrasonic assisted extraction black rice anthocyanins is a kind of effective method.
Using anhydrous ethanol as extracting solvent,the technique of ultrasonic assisted extraction of black rice anthocyanins and its antioxidation were investigated.The results showed that the optimum extraction codition were temperature 50℃,ethanol volume fraction 35%,feed liquid ratio of 1:4,extracting time for 30 min.And comparison with no ultrasonic assisted extraction,ultrasonic assisted extraction black rice anthocyanins when ultrasonic power is 90 W,ultrasonic extraction time is 4 min,its antioxidation is the largest,so the ultrasonic assisted extraction black rice anthocyanins is a kind of effective method.
2013, 28(1)
:20-24.
doi: 10.3969/j.issn.2095-476X.2013.01.005
Abstract:
The changes in grass carp muscle proteins during storage at 4℃ were investigated by SDS-PAGE and DSC.The results showed that the drip loss increased gradually during storage.As shown by SDS-PAGE,no significant degradation of muscle proteins were observed,however,the extractability of salt soluble proteins initially increased,then remained stable,and finally decreased,the tendency of which was contrary to that of insoluble proteins.As demonstrated by DSC,the myosin peak became more and more sharp during storage and the sarcoplasmic protein peak disappeared gradually,while the actin peak remained almost unchanged.
The changes in grass carp muscle proteins during storage at 4℃ were investigated by SDS-PAGE and DSC.The results showed that the drip loss increased gradually during storage.As shown by SDS-PAGE,no significant degradation of muscle proteins were observed,however,the extractability of salt soluble proteins initially increased,then remained stable,and finally decreased,the tendency of which was contrary to that of insoluble proteins.As demonstrated by DSC,the myosin peak became more and more sharp during storage and the sarcoplasmic protein peak disappeared gradually,while the actin peak remained almost unchanged.
2013, 28(1)
:25-29.
doi: 10.3969/j.issn.2095-476X.2013.01.006
Abstract:
he safety of 6-hydroxynicotine and nicotine was compared through toxicology test.The acute toxicity and accumulative test was carried out on SPF mice(each of 30~35 g).After 35 d intragastrically each of 1.00 mg,0.75 mg,0.5 mg,0.25 mg of nicotine and 6-hydroxynicotine(about receive the amount of a man pumping 20 cigarettes a day 8,6,4,2 times),the organ coefficient of heart,liver,spleen,lung and kidney were calculated and bloodindicators of ALT,AST,TG were determined,the pathological examination was also done using liver,lung and kidney tissue.The results showed that 6-hydroxynicotine compared to nicotine significantly reduced in toxicity(P < 0.05),low doses of nicotine does not cause organ lesions in mice.
he safety of 6-hydroxynicotine and nicotine was compared through toxicology test.The acute toxicity and accumulative test was carried out on SPF mice(each of 30~35 g).After 35 d intragastrically each of 1.00 mg,0.75 mg,0.5 mg,0.25 mg of nicotine and 6-hydroxynicotine(about receive the amount of a man pumping 20 cigarettes a day 8,6,4,2 times),the organ coefficient of heart,liver,spleen,lung and kidney were calculated and bloodindicators of ALT,AST,TG were determined,the pathological examination was also done using liver,lung and kidney tissue.The results showed that 6-hydroxynicotine compared to nicotine significantly reduced in toxicity(P < 0.05),low doses of nicotine does not cause organ lesions in mice.
2013, 28(1)
:30-33.
doi: 10.3969/j.issn.2095-476X.2013.01.007
Abstract:
Based on the material of domestic high-quality tobacco leaf,quality differences between ten substituting modules and Zimbabwe tobacco leaves were studied by using the circular design concept for module progressively,and high percentage of substituting Zimbabwe tobacco leaf were tried in tobacco products.The results showed that it could not make up the quality differences between combination module,function module and Zimbabwe tobacco leaves by a single level formula adjusting,functional spices adding.The superior module TD31 which was selected by formula of leaf groups adjusting,functional spices adding,group processing deal with and so on,the 30% of Zimbabwe tobacco leaf could be substituted in domestic kind of cigarette product.
Based on the material of domestic high-quality tobacco leaf,quality differences between ten substituting modules and Zimbabwe tobacco leaves were studied by using the circular design concept for module progressively,and high percentage of substituting Zimbabwe tobacco leaf were tried in tobacco products.The results showed that it could not make up the quality differences between combination module,function module and Zimbabwe tobacco leaves by a single level formula adjusting,functional spices adding.The superior module TD31 which was selected by formula of leaf groups adjusting,functional spices adding,group processing deal with and so on,the 30% of Zimbabwe tobacco leaf could be substituted in domestic kind of cigarette product.
2013, 28(1)
:34-37.
doi: 10.3969/j.issn.2095-476X.2013.01.008
Abstract:
The tobacco concrete from discarded tobacco leaves were prepared by fermentation of aroma producing yeast XINJING SP-3.The process was as following:extract of discarded tobacco leaves was added 10% glucose and 1% yeast.After sterilization,the tobacco extract was fermented at 30℃ for 7 d.The flavor was extracted by simultaneous distillation extraction and the volatile components of extract were analyzed by GC-MS.Comparing with common tobacco extract,the special aroma components of the extract were:5-methyl furfural,β-phenyl ethyl alcohol,acetyl pyrrole,megastigmatrienone,3-methyl indole,etc.Addition of 0.01 g to 0.05 g special tobacco flavor to 100 g cigarette could augment and enhance the aroma and taste of smoking tobacco and reduce irritancy of the smoking cigarette.The special tobacco flavor could preferably improve the aroma property of tobacco than the normal tobacco flavor.
The tobacco concrete from discarded tobacco leaves were prepared by fermentation of aroma producing yeast XINJING SP-3.The process was as following:extract of discarded tobacco leaves was added 10% glucose and 1% yeast.After sterilization,the tobacco extract was fermented at 30℃ for 7 d.The flavor was extracted by simultaneous distillation extraction and the volatile components of extract were analyzed by GC-MS.Comparing with common tobacco extract,the special aroma components of the extract were:5-methyl furfural,β-phenyl ethyl alcohol,acetyl pyrrole,megastigmatrienone,3-methyl indole,etc.Addition of 0.01 g to 0.05 g special tobacco flavor to 100 g cigarette could augment and enhance the aroma and taste of smoking tobacco and reduce irritancy of the smoking cigarette.The special tobacco flavor could preferably improve the aroma property of tobacco than the normal tobacco flavor.
2013, 28(1)
:38-40.
doi: 10.3969/j.issn.2095-476X.2013.01.009
Abstract:
Reconstituted tobacco containing different proportion of tea,by using the coating method,were mixed to tobacco and produce blended tobacco cigarettes,cigarette smoke was trapped with the smoking machine,the total particulate matter of the mainstream smoke was collected,the filters which contained particulate matter of the smoke was extracted through the simultaneous and extraction method (SDE),and then analyzed qualitatively and quantitatively by using the GC-MS.Compared with the blank control sample,it showed that the content of aromatic component in blended tobacco containing different proportion of tea increased in different degrees,and with the increasing of tea added,the total aromatic component of 10% and 14% cigarette samples increased 64.9% and 69.3% respectively.
Reconstituted tobacco containing different proportion of tea,by using the coating method,were mixed to tobacco and produce blended tobacco cigarettes,cigarette smoke was trapped with the smoking machine,the total particulate matter of the mainstream smoke was collected,the filters which contained particulate matter of the smoke was extracted through the simultaneous and extraction method (SDE),and then analyzed qualitatively and quantitatively by using the GC-MS.Compared with the blank control sample,it showed that the content of aromatic component in blended tobacco containing different proportion of tea increased in different degrees,and with the increasing of tea added,the total aromatic component of 10% and 14% cigarette samples increased 64.9% and 69.3% respectively.
Analysis of exopolysaccharides from fermented Pleurotus pulmonarius and its application in cigarette
2013, 28(1)
:41-44.
doi: 10.3969/j.issn.2095-476X.2013.01.010
Abstract:
Pleurotus pulmonarius was cultivated in a 5 L stirred-tank reactor,and exopolysaccharides(EPS) were extracted from fermentation broth.After EPS was deproteinized by Sevag method,one group of EPS was obtained from the culture filtrates by gel filtration chromatography on Sepharose CL-6B.FT-IR spectroscopy was used for obtaining vibrational spectra of the purified EPS fraction.Polysaccharide is acidic polysaccharides,mainly consist of glucose and mannose.Different concentrations of EPS from Coriolus versicolor were injected in cigarettes,and calculated the transfer rates.The results showed that the transfer rate of EPS in gas in the rage of 1.26%~12.40% and the adding 0.04% EPS could improve the quality,increase the amount of aroma,enhanced sense of sweet,raise sophistication and cover the smoking foreign gas,The results provided a strong support for the application of EPS in cigarette industry.
Pleurotus pulmonarius was cultivated in a 5 L stirred-tank reactor,and exopolysaccharides(EPS) were extracted from fermentation broth.After EPS was deproteinized by Sevag method,one group of EPS was obtained from the culture filtrates by gel filtration chromatography on Sepharose CL-6B.FT-IR spectroscopy was used for obtaining vibrational spectra of the purified EPS fraction.Polysaccharide is acidic polysaccharides,mainly consist of glucose and mannose.Different concentrations of EPS from Coriolus versicolor were injected in cigarettes,and calculated the transfer rates.The results showed that the transfer rate of EPS in gas in the rage of 1.26%~12.40% and the adding 0.04% EPS could improve the quality,increase the amount of aroma,enhanced sense of sweet,raise sophistication and cover the smoking foreign gas,The results provided a strong support for the application of EPS in cigarette industry.
2013, 28(1)
:45-49.
doi: 10.3969/j.issn.2095-476X.2013.01.011
Abstract:
Based on the density differences of cut filler,a cut fillers homogeneity method which using CO2 expanded tobacco as the tracer was used to analyze the influence of sampling volume and frequency on the mixing uniformity of cut filler in cigarettes statistically.The results showed that:1)the mean of CO2 expanded tobacco content in cigarette samples tended towards stability gradually while the standard deviation decreased and tended towards stability gradually with the increase of the sampling volume.The variance of expanded tobacco content showed significant difference when selecting the whole sampling volume as a group,and the variance of expanded tobacco content had not significant difference among the more than 90 g sampling amount group,while the mean of expanded tobacco content showed no obvious difference when the sampling amount is greater than 30 g. 2)The variance of expanded tobacco content in cigarette samples had not significant difference between each number of samples group while the mean of expanded tobacco content had not significant difference with the sample of 55 sampling number group when the sampling number reached 10.
Based on the density differences of cut filler,a cut fillers homogeneity method which using CO2 expanded tobacco as the tracer was used to analyze the influence of sampling volume and frequency on the mixing uniformity of cut filler in cigarettes statistically.The results showed that:1)the mean of CO2 expanded tobacco content in cigarette samples tended towards stability gradually while the standard deviation decreased and tended towards stability gradually with the increase of the sampling volume.The variance of expanded tobacco content showed significant difference when selecting the whole sampling volume as a group,and the variance of expanded tobacco content had not significant difference among the more than 90 g sampling amount group,while the mean of expanded tobacco content showed no obvious difference when the sampling amount is greater than 30 g. 2)The variance of expanded tobacco content in cigarette samples had not significant difference between each number of samples group while the mean of expanded tobacco content had not significant difference with the sample of 55 sampling number group when the sampling number reached 10.
2013, 28(1)
:50-52,56.
doi: 10.3969/j.issn.2095-476X.2013.01.012
Abstract:
Seven packaging bodies of PI have been designed and a series of geometric optimization, energy optimization and molecular dynamics optimization of which is carried out by MS 3.0 software. The amorphous structure, parameters of cell, final density, cohesive density and solution parameter of PI packaging bodies are predicted by the analysis module of MS 3.0 software. The results of simulation illustrated that the density of PI packaging bodies is similar and the maximum error is 1.9%, which reduces 11.5% than the first; The cohesive solution parameters are less than theoretic value of PI; In the process of molecule dynamics simulation, bond length and angle versus time are almost unchanged; The results of radial distribution function demonstrate that there is a amorphous structure of having short-range order but without long-range order for PI, which is close to real PI thin film and is used to further simulation and calculation.
Seven packaging bodies of PI have been designed and a series of geometric optimization, energy optimization and molecular dynamics optimization of which is carried out by MS 3.0 software. The amorphous structure, parameters of cell, final density, cohesive density and solution parameter of PI packaging bodies are predicted by the analysis module of MS 3.0 software. The results of simulation illustrated that the density of PI packaging bodies is similar and the maximum error is 1.9%, which reduces 11.5% than the first; The cohesive solution parameters are less than theoretic value of PI; In the process of molecule dynamics simulation, bond length and angle versus time are almost unchanged; The results of radial distribution function demonstrate that there is a amorphous structure of having short-range order but without long-range order for PI, which is close to real PI thin film and is used to further simulation and calculation.
2013, 28(1)
:53-56.
doi: 10.3969/j.issn.2095-476X.2013.01.013
Abstract:
The methods of poly-lactic acid waste recycling include the physical modification,chemical modification and physi-chemical modification.At present, domestic and foreign enterprises mainly use physi-chemical methods of tackifying and heat resistance to improve the difficult molding technology and the problem of insufficient heat resistance.With the cost reduction and performance improvement, the application scope of PLA will be more and more widely, especially in the medical field, it has other irreplaceable role.Therefore, the PLA waste re-use should be extended to the field of medicine, and try to modify PLA waste with new materials to develop new uses of the PLA material in the base of overcoming the shortcomings.
The methods of poly-lactic acid waste recycling include the physical modification,chemical modification and physi-chemical modification.At present, domestic and foreign enterprises mainly use physi-chemical methods of tackifying and heat resistance to improve the difficult molding technology and the problem of insufficient heat resistance.With the cost reduction and performance improvement, the application scope of PLA will be more and more widely, especially in the medical field, it has other irreplaceable role.Therefore, the PLA waste re-use should be extended to the field of medicine, and try to modify PLA waste with new materials to develop new uses of the PLA material in the base of overcoming the shortcomings.
2013, 28(1)
:57-61.
doi: 10.3969/j.issn.2095-476X.2013.01.014
Abstract:
It is necessary to determine a reasonable bore distance when we design the outdoors heat exchanger of the ground-coupled heat pump. The larger distance will cause the waste of ground source,on the contrary, it will change the soil temparature and reduce the efficiency of heat exchanger. So,the effect of fluid velocity on thermal radius was simulated through builting the system runing cost function when system had worked 30 d.The computational results showed that thermal radius is 0.95 m when fluid velocity is 0.4 m/s, which increases with increasing fluid velocity. But the thermal radius range is obviously slight when fluid velocity is more than 0.6 m/s.
It is necessary to determine a reasonable bore distance when we design the outdoors heat exchanger of the ground-coupled heat pump. The larger distance will cause the waste of ground source,on the contrary, it will change the soil temparature and reduce the efficiency of heat exchanger. So,the effect of fluid velocity on thermal radius was simulated through builting the system runing cost function when system had worked 30 d.The computational results showed that thermal radius is 0.95 m when fluid velocity is 0.4 m/s, which increases with increasing fluid velocity. But the thermal radius range is obviously slight when fluid velocity is more than 0.6 m/s.
2013, 28(1)
:62-65.
doi: 10.3969/j.issn.2095-476X.2013.01.015
Abstract:
A design method that intelligent control of motion trajectory based on 5R parallel stacking mechanism was investigated.By analysis the control system and the inverse kinematics of the 5R mechanism, it can be concluded when the 5R is given two original moving parts, it can uniquely identify the pose of the rod end of the implementation of parts, in seeking the position and orientation inverse solution with the minimum principle that the square of the residuals between the prime mover rotation angle of adjacent track points, the only connecting rod track can't determine the only two original moving parts. It is a good method to solve the intelligent control of the 5R institutions by teaching and playback method. It can also reduce the programming effort and improve the efficiency of stacking work.
A design method that intelligent control of motion trajectory based on 5R parallel stacking mechanism was investigated.By analysis the control system and the inverse kinematics of the 5R mechanism, it can be concluded when the 5R is given two original moving parts, it can uniquely identify the pose of the rod end of the implementation of parts, in seeking the position and orientation inverse solution with the minimum principle that the square of the residuals between the prime mover rotation angle of adjacent track points, the only connecting rod track can't determine the only two original moving parts. It is a good method to solve the intelligent control of the 5R institutions by teaching and playback method. It can also reduce the programming effort and improve the efficiency of stacking work.
2013, 28(1)
:66-71.
doi: 10.3969/j.issn.2095-476X.2013.01.016
Abstract:
To research the mechanical behavior of circular concrete filled steel tubular (CFST) truss, four truss specimens of the different sections such as rectangular truss,inverse-triangular truss,trapezoid truss and triangular truss were tested under static point loading.Results of these tests showed that truss specimens are stressed more in the segment 0-2/6l of the bottom chord,expect specimen TT which is stressed more in the top chord.The difference among these trusses sections has a great influence on the axial force of chord, and each segment bears quite large in-plane bending moment, but it has different influence on the web members.Among these trusses,webs of specimen IT have a more reasonable condition.The influence on web in-plane bending moment is larger and larger as the following order:rectangular section, trapezoid section, inverted triangularsection,furthermore, force condition of bottom chords is more and more complex.To the top chords filled concrete, section "weaken" from rectangular section to trapezoid section, inverted triangular section, and triangular section makes a different influence on in-plane bending moment of each segment.
To research the mechanical behavior of circular concrete filled steel tubular (CFST) truss, four truss specimens of the different sections such as rectangular truss,inverse-triangular truss,trapezoid truss and triangular truss were tested under static point loading.Results of these tests showed that truss specimens are stressed more in the segment 0-2/6l of the bottom chord,expect specimen TT which is stressed more in the top chord.The difference among these trusses sections has a great influence on the axial force of chord, and each segment bears quite large in-plane bending moment, but it has different influence on the web members.Among these trusses,webs of specimen IT have a more reasonable condition.The influence on web in-plane bending moment is larger and larger as the following order:rectangular section, trapezoid section, inverted triangularsection,furthermore, force condition of bottom chords is more and more complex.To the top chords filled concrete, section "weaken" from rectangular section to trapezoid section, inverted triangular section, and triangular section makes a different influence on in-plane bending moment of each segment.
2013, 28(1)
:72-75.
doi: 10.3969/j.issn.2095-476X.2013.01.017
Abstract:
To research the mechanical property of steel beam and concrete column composite joints with extended end-plate connections,pseudo-static test,low cyclic loading test,was executed on 7 test specimens,all of which were welded compound-ring-hoop concrete column and cellular steel beam composite joints.The experimental results reflected that the load value was smaller when steel beam and concrete column composite joints crack with extended end-plate connections was appearing; after the test specimens yielded, the main X-type crossing incline shear cracks were appearing in areas of joints; when it came to the stage of destroy, continuous seam appeared in areas of joints core, moreover, part of concrete in those areas was crushed and plumped, hoops yielded, stiffness degraded, and test specimens were destroyed; finally, the destroying pattern in aforementioned areas was shear compression failure.Compared with other experimental results, the fastest energy-consuming test specimen were those that with extended end-plate bolted connections,hoops,longitudinal bars and concrete in areas of joints core can fully show their functions.As a result,the extended end-plate bolted connection was a comparatively reasonable pattern of joints.
To research the mechanical property of steel beam and concrete column composite joints with extended end-plate connections,pseudo-static test,low cyclic loading test,was executed on 7 test specimens,all of which were welded compound-ring-hoop concrete column and cellular steel beam composite joints.The experimental results reflected that the load value was smaller when steel beam and concrete column composite joints crack with extended end-plate connections was appearing; after the test specimens yielded, the main X-type crossing incline shear cracks were appearing in areas of joints; when it came to the stage of destroy, continuous seam appeared in areas of joints core, moreover, part of concrete in those areas was crushed and plumped, hoops yielded, stiffness degraded, and test specimens were destroyed; finally, the destroying pattern in aforementioned areas was shear compression failure.Compared with other experimental results, the fastest energy-consuming test specimen were those that with extended end-plate bolted connections,hoops,longitudinal bars and concrete in areas of joints core can fully show their functions.As a result,the extended end-plate bolted connection was a comparatively reasonable pattern of joints.
2013, 28(1)
:76-79.
doi: 10.3969/j.issn.2095-476X.2013.01.018
Abstract:
On the engineering background of rare domestic large-span and super-large cross-section tunnel-Qianou tunnel,data of surrounding rock deformation was obtained through in-situ monitoring.Firstly,those data were cut off by upper limited velocity method; Then,they were analysed by Wavelet.Besides,a 2-D numerical model was set up by ANSYS to simulate the construction process.Some deformation laws were obtained as follows:The horizontal convergent calculated value of upper right heading was 18 mm,which was obviously much more than another two orientations,8.6 mm and 3.8 mm respectively.While,the horizontal convergent calculated value of whole section was 7.9 mm,which was approximately coincident with another two orientations,4.5 mm and 4.4 mm,respectively;The construction method had a comparatively more obviously influence on the convergent curve of upper right heading,which showed an obviously periodical character,while,the periodical character showed by the convergent curve of whole section was not that obvious.
On the engineering background of rare domestic large-span and super-large cross-section tunnel-Qianou tunnel,data of surrounding rock deformation was obtained through in-situ monitoring.Firstly,those data were cut off by upper limited velocity method; Then,they were analysed by Wavelet.Besides,a 2-D numerical model was set up by ANSYS to simulate the construction process.Some deformation laws were obtained as follows:The horizontal convergent calculated value of upper right heading was 18 mm,which was obviously much more than another two orientations,8.6 mm and 3.8 mm respectively.While,the horizontal convergent calculated value of whole section was 7.9 mm,which was approximately coincident with another two orientations,4.5 mm and 4.4 mm,respectively;The construction method had a comparatively more obviously influence on the convergent curve of upper right heading,which showed an obviously periodical character,while,the periodical character showed by the convergent curve of whole section was not that obvious.
2013, 28(1)
:80-82.
doi: 10.3969/j.issn.2095-476X.2013.01.019
Abstract:
A finite element model on CHS brace-H-section steel chord T-joints was generated by Abaqus and validated by comparing the ultimate capacity, deformation process and failure mode with experimental results. The result showed that under the effect of axial pressure, elephant-foot buckling and local buckling occur at the root of brace, and flange buckling occurs at chord; in engineering it should be avoided that the thickness of brace is relatively smaller than chord, or joints should be strengthened; CHS brace-H-section steel chord T-joints has strong plastic deformation capacity from being yield.
A finite element model on CHS brace-H-section steel chord T-joints was generated by Abaqus and validated by comparing the ultimate capacity, deformation process and failure mode with experimental results. The result showed that under the effect of axial pressure, elephant-foot buckling and local buckling occur at the root of brace, and flange buckling occurs at chord; in engineering it should be avoided that the thickness of brace is relatively smaller than chord, or joints should be strengthened; CHS brace-H-section steel chord T-joints has strong plastic deformation capacity from being yield.
2013, 28(1)
:83-85.
doi: 10.3969/j.issn.2095-476X.2013.01.020
Abstract:
Aiming at the problem of low efficiency,large error and high cost in bending of sheet metal parts production,through parameter setting with K factor,at the same time listing the bending coefficient table of bending compensation and bending duduction,the high consistency between production and design can be realized by 3D software.
Aiming at the problem of low efficiency,large error and high cost in bending of sheet metal parts production,through parameter setting with K factor,at the same time listing the bending coefficient table of bending compensation and bending duduction,the high consistency between production and design can be realized by 3D software.
2013, 28(1)
:86-91.
doi: 10.3969/j.issn.2095-476X.2013.01.021
Abstract:
Considering the characteristics and computation superiority of quaternion representing body attitude movement, and aiming at the initial alignment procedure of strapdown inertial navigation system (SINS) with large initial misalignment angles,its multiplicative quaternion error model were developed. It proposes the new calculation method in which the attitude matrix cost function was constructed to calculate its maximum eigenvalues, and select the eigenvector which corresponds to the maximum eigenvalue as the predicted quaternion mean to guarantee its unit normalization and the sign invariability. The multiplicative quaternion error representing the distance between quaternion Sigma-points and the predicted quaternion mean calculates the quaternion prediction error variance matrix, which can effectively overcome the application limits for SPKF algorithms in quaternion filtering implementation. Combined with the central divided difference filtering (CDKF) algorithm, it proposes the new quaternion CDKF algorithm (QCDKF) for quaternion filtering problems in the SINS' simulation experiments. The simulations results showed that, compared with EKF algorithm, the proposed algorithm can significantly improve the filtering precision of both attitude misalignment angles and velocity and have better stabilization in the numerical calculation.
Considering the characteristics and computation superiority of quaternion representing body attitude movement, and aiming at the initial alignment procedure of strapdown inertial navigation system (SINS) with large initial misalignment angles,its multiplicative quaternion error model were developed. It proposes the new calculation method in which the attitude matrix cost function was constructed to calculate its maximum eigenvalues, and select the eigenvector which corresponds to the maximum eigenvalue as the predicted quaternion mean to guarantee its unit normalization and the sign invariability. The multiplicative quaternion error representing the distance between quaternion Sigma-points and the predicted quaternion mean calculates the quaternion prediction error variance matrix, which can effectively overcome the application limits for SPKF algorithms in quaternion filtering implementation. Combined with the central divided difference filtering (CDKF) algorithm, it proposes the new quaternion CDKF algorithm (QCDKF) for quaternion filtering problems in the SINS' simulation experiments. The simulations results showed that, compared with EKF algorithm, the proposed algorithm can significantly improve the filtering precision of both attitude misalignment angles and velocity and have better stabilization in the numerical calculation.
2013, 28(1)
:92-95.
doi: 10.3969/j.issn.2095-476X.2013.01.022
Abstract:
A design method of measuring SF6 gas decompositions in GIS based on gas sensor was put forward.A new type of filter was applied for the system to get rid of the inherent defect about cross interference between gas sensors; One special constant potential circuit was designed according to the traits of sensors to insure the exact signal; The adaptive federated Kalman filtering was proved, which could make up the infection about temperature and flux to the sensors, as well as, null shift can be resolved. The practice results showed that the system has the following advantages:simple structure, convenient operation, the measuring accuracy, the quick survey speed, the strong antijamming ability and so on.It can be used to test SF6 gas decompositions on line and portably.
A design method of measuring SF6 gas decompositions in GIS based on gas sensor was put forward.A new type of filter was applied for the system to get rid of the inherent defect about cross interference between gas sensors; One special constant potential circuit was designed according to the traits of sensors to insure the exact signal; The adaptive federated Kalman filtering was proved, which could make up the infection about temperature and flux to the sensors, as well as, null shift can be resolved. The practice results showed that the system has the following advantages:simple structure, convenient operation, the measuring accuracy, the quick survey speed, the strong antijamming ability and so on.It can be used to test SF6 gas decompositions on line and portably.
Research on temperature variation of dry-type transformers based on thermal equivalent circuit model
2013, 28(1)
:96-99.
doi: 10.3969/j.issn.2095-476X.2013.01.023
Abstract:
Based on the principle of thermal-electrical analogy, a thermal equivalent circuit model of one dry-type transformer was built. The temperature variation of the dry-type transformer was studied through simulating the thermal equivalent circuit model by software ATPDraw5.4 when its load changed within the limits of rated load or overload, or it was shorted in secondary circuit.The simulation results showed that the temperatures of the dry-type transformer change in accordance with exponential functions when its load changes within the limits of rated load or overload, and increse rapidly and greatly in accordance with power functions when it is shorted in secondary circuit.
Based on the principle of thermal-electrical analogy, a thermal equivalent circuit model of one dry-type transformer was built. The temperature variation of the dry-type transformer was studied through simulating the thermal equivalent circuit model by software ATPDraw5.4 when its load changed within the limits of rated load or overload, or it was shorted in secondary circuit.The simulation results showed that the temperatures of the dry-type transformer change in accordance with exponential functions when its load changes within the limits of rated load or overload, and increse rapidly and greatly in accordance with power functions when it is shorted in secondary circuit.
2013, 28(1)
:100-104.
doi: 10.3969/j.issn.2095-476X.2013.01.024
Abstract:
According to the law of electromagnetic induction and the characteristics of current magnetic field of solenoid,a finite element model of the magnetic field on the surface or the interior of long straight solenoid was established.By means of theoretical deduction and numerical analysis based on the law of biot savart and Ampere circuital theorem of magnetic field in a straight solenoid,the characteristics of distribution of magnetic field and its analytical solution were obtained.The simulation was carried out on using of Ansoft Maxwell 3D engineering electromagnetic field finite element software,the consistency of the result and the intuitive and convenient of using ANSYS software for electromagnetic field analysis were verified.
According to the law of electromagnetic induction and the characteristics of current magnetic field of solenoid,a finite element model of the magnetic field on the surface or the interior of long straight solenoid was established.By means of theoretical deduction and numerical analysis based on the law of biot savart and Ampere circuital theorem of magnetic field in a straight solenoid,the characteristics of distribution of magnetic field and its analytical solution were obtained.The simulation was carried out on using of Ansoft Maxwell 3D engineering electromagnetic field finite element software,the consistency of the result and the intuitive and convenient of using ANSYS software for electromagnetic field analysis were verified.
2013, 28(1)
:105-108.
doi: 10.3969/j.issn.2095-476X.2013.01.025
Abstract:
A solid state power amplifier module was designed.The two thermal components with power amplifier module and power supply module were independently fixed two opposite cooling radiators. According to the thermal quantity,the height of cooling tooth was adjusted, and the cabinet was constructed a wind path by the fans of its both sides. On the base of the structure design, theoretical calculation was used to verify, and the software of Icepak was used to analyse the simulation thermal model, and the test result showed the feasibility.
A solid state power amplifier module was designed.The two thermal components with power amplifier module and power supply module were independently fixed two opposite cooling radiators. According to the thermal quantity,the height of cooling tooth was adjusted, and the cabinet was constructed a wind path by the fans of its both sides. On the base of the structure design, theoretical calculation was used to verify, and the software of Icepak was used to analyse the simulation thermal model, and the test result showed the feasibility.
Journal Information
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
Subeditor：Qu Shuanghong
Edited & published by：Editorial Department of Journal of Light Industry
CN 41-1437/TS
ISSN 2096-1553
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