Annealing nanodiamonds(ND) at high temperatures up to 1700 ℃ is a common method to synthesize carbon onions. The transformation from NDs to carbon onions is particularly interesting because of carbon onions' pote...Annealing nanodiamonds(ND) at high temperatures up to 1700 ℃ is a common method to synthesize carbon onions. The transformation from NDs to carbon onions is particularly interesting because of carbon onions' potential in the field of tribology and their application in ultra-charge/discharge devices. In this paper, a novel surface-enhanced Raman scattering technique that involves coating the sample with nanoscopic gold particles is proposed to characterize the NDs after different annealing treatments. Conventional Raman and surfaceenhanced Raman spectra were obtained, and the changes of peak parameters as the function of annealing temperature were evaluated. It was found that the widths of the D and the G peaks decreased with increasing annealing temperature, reflecting an improved order in the sp^2-hybridized carbon during the transformation from NDs to carbon onions. After annealing at 1700 ℃, the sp^2?carbon was highly ordered, indicating desirable electrical conductivity and lubricity. With increasing annealing temperature, the D peak showed a blue shift of almost30 cm^(-1), while the G peak merely shifted by 5 cm^(-1). For annealing temperatures above 1100 ℃, an increase of intensity ratio ID/IGwas observed. Compared to the uncoated area, red shifts of 0.5-2 cm^(-1) and of 5-9 cm^(-1) for the G and D peaks, respectively, were detected for the gold-coated area, which was due to the coupling of the plasmons and the phonons of the samples.展开更多
Microbial counts （total aerobic psychrotrophic count （TPC）, lactic acid bacteria （LAB）, coliforms, pseudomonads, yeasts） and sensory properties of sliced onions stored at different temperatures and air compositi...Microbial counts （total aerobic psychrotrophic count （TPC）, lactic acid bacteria （LAB）, coliforms, pseudomonads, yeasts） and sensory properties of sliced onions stored at different temperatures and air compositions were investigated. Microbial counts were fitted to the modified Gompertz equation and the growth parameters of microorganisms (the initial cell number （N0）, maximum cell number (Nmax), maximum specific growth rate (μmax), lag-phase （（λ）） were obtained as derived parameters. The relationships between growth parameters of microorganisms and the microbial or sensory shelf life were built. The results showed that microbial counts increased and sensory qualities decreased during storage. TPC was predominant bacteria associated with spoilage of sliced onions under tested temperatures and air conditions. High correlation coefficients （r） were found between the lag time （λ） of TPC, coliforms, pseudomonads, yeasts and the microbial or sensory shelf life. The correlations between microbial or sensory shelf life and μmax of five microorganisms were between -0.69 and -0.86. The initial microbial counts （N0） of five microorganisms strains only showed a little correlation, and the maximum microbial counts (Nmax) showed no obvious correlation with shelf life except for LAB and yeasts.展开更多
[Objective] This study aimed to compare the similarities and dissimilarities in karyotypes of purple and white onions,so as to lay foundation for further studying its genetic improvement and breeding more onion variet...[Objective] This study aimed to compare the similarities and dissimilarities in karyotypes of purple and white onions,so as to lay foundation for further studying its genetic improvement and breeding more onion varieties.[Method] Sections of root-tip cells were prepared by normal wafer method.Photomicrography was adopted to produce the high-quality chromosome specimen.Finally,karyotype analysis was conducted using Adobe Photoshop.[Result] Chromosome karyotype analysis on the root-tip showed that the chromosome number of both purple and white onions was 2n=2x=16.Among the 16 chromosomes of both the onions,no satellite chromosome was found.By measuring and calculating,it was found that the karyotype of the studied white union belonged to the lowly evolutional 2A type,and its karyotype formula was 2n=2x=16=14 m ＋2St,with the karyotype asymmetry coefficient of 58.67%.No obvious centromere was observed in the sections of purple onion.[Conclusion] The karyotypes of white and purple unions are similar and we can infer from this fact that the reason of different characters between both the onions is not due to the chromosome aberration.This karyotype formula and asymmetrical karyotype coefficient have some reference values on the identification of onion variety resources.展开更多
The rational construction of microstructure and composition with enhanced Maxwell-Wagner-Sillars effect(MWSE)is still a challenging direction for reinforcing electromagnetic wave(EMW)absorption performance,and the rel...The rational construction of microstructure and composition with enhanced Maxwell-Wagner-Sillars effect(MWSE)is still a challenging direction for reinforcing electromagnetic wave(EMW)absorption performance,and the related EMW attenuation mechanism has rarely been elucidated.Herein,MWSE boostedβ-chitin/carbon nano-onions/Ni–P composites is prepared according to the heterointerface engineering strategy via facile layer-by-layer electrostatic assembly and electroless plating techniques.The heterogeneous interface is reinforced from the aspect of porous skeleton,nanomaterials and multilayer construction.The composites exhibit competitive EMW response mechanism between the conductive loss and the polarization/magnetic loss,as describing like the story of“The Hare and the Tortoise”.As a result,the composites not only achieve a minimum reflection loss(RL_(min))of−50.83 dB and an effective bandwidth of 6.8 GHz,but also present remarkable EMW interference shielding effectiveness of 66.66 dB.In addition,diverse functions such as good thermal insulation,infrared shielding and photothermal performance were also achieved in the hybrid composites as a result of intrinsic morphology and chemicophysics properties.Therefore,we believe that the boosted MWSE open up a novel orientation toward developing multifunctional composites with high-efficient EMW response and thermal management.展开更多
Onion（Allium cepa L.） is a very important vegetable crop widely cultivated throughout the world. In this study, we measured total anthocyanins and flavonols of onions of three colors. The fresh weight（FW） of total...Onion（Allium cepa L.） is a very important vegetable crop widely cultivated throughout the world. In this study, we measured total anthocyanins and flavonols of onions of three colors. The fresh weight（FW） of total anthocyanins were（29.99±1.19）,（9.64±1.30） and（0.75±0.40） mg 100 g^–1 fruit in red, yellow and white onions, respectively. Likewise, the FW of total flavonoids were（111.10±5.98）,（36.64±3.59）, and 0 mg 100 g^–1 in red, yellow and white, respectively. Four types of anthocyanins（delphinidin 3,5-diglycosides, cyanidin 3,5-diglycosides, cyanidin 3-glycosides and cyanidin 3-（6′′-malonyl）-glucopyranoside） and two kinds of flavonoids（quercetin and quercetin 3-glycosides） were identified in two varieties（red and yellow bulb） of onions by HPLC/DAD-ESI/MS. The total polyphenol contents were also measured by means of Folin-Ciocalteu method. Moreover, all the concentrations of anthocyanins, flavonoids and polyphenols showed significantly positive correlations with antioxidant activities measured by DPPH˙, ABTS˙＋ and FRAP assays. This study provided information on anthocyanin and flavonoids compositions that will be useful for onion breeding.展开更多
Onion(Allium cepa L.)is a common biennial herb,and contains allicin compounds which can kill harmful microorganism.The antibacterial effects of raw and mature onion juice of purple,yellow and white-skinned onions at d...Onion(Allium cepa L.)is a common biennial herb,and contains allicin compounds which can kill harmful microorganism.The antibacterial effects of raw and mature onion juice of purple,yellow and white-skinned onions at different concentrations on Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were studied.There were differences among the antibacterial effects of raw and mature onion juice of purple,yellow and white-skinned onions at different concentrations.What was more,the antibacterial effects of raw onion juice were better than those of the mature one.The antibacterial effects of high concentration onion juice were better than those of the low one.The content of the total flavonoids in raw purple onion was higher than that in mature onion,and reached extremely significant levels in 50%,75%and 100%,respectively.Through comparison,it was found that onion juice of purple-skinned had the best suppression effects on S.aureus(gram-positive bacterium)and E.coli(gram-negative bacterium),and gram-positive bacterium had better suppression effects than gram-negative bacterium.It wound provide the basis about bioactive function and antibacterial drugs.展开更多
The content of polyphenolic substances in commercial onions has been determined. The antioxidant activity of their ethanolic extracts, as well as their effects on the oxidation of edible corn oil during accelerated ag...The content of polyphenolic substances in commercial onions has been determined. The antioxidant activity of their ethanolic extracts, as well as their effects on the oxidation of edible corn oil during accelerated ageing was studied. Maceration of taxonomically identified commercial vegetable samples, previously peeled and thinly sliced, was carried out at ambient temperature, out of direct light, with occasional agitation and ultrasound, employing 95% ethyl alcohol as the extraction solvent, allowing them to stand for 7 days. The total polyphenolic contents were determined on the filtrated extracts using the Folin-Ciocalteau method. The antioxidant activity was evaluated on emulsions of ethanolic extracts of onion prepared in edible commercial corn oil, using sorbitan monooleate as emulsifying agent. The peroxide values were analyzed using the iodometric method;oxidation induction times were obtained from the peroxide evolution graphs, using the tan- gent method. Oil samples emulsified with ethanolic onion extracts showed an extension of the induction period. A 7-day ageing study at 45?C was additionally performed to determine the conjugated dienes on pure commercial corn oil and its emulsions by visible spectrophotometry. The spectral analysis showed an increase of the measured absorbancies in oil samples without additives and no change for the oils emulsified with onion extract. An increasing of diene values was observed for corn oil without additives during ageing;no changes in the value were observed in oils emulsified with onion extracts.展开更多
This research was carried out to assess the effect of different varieties and mulching types on insect and disease infestation,and the yield of onions.The experiment was conducted in Sangkat TuekVil,KrongSiem Reap,in ...This research was carried out to assess the effect of different varieties and mulching types on insect and disease infestation,and the yield of onions.The experiment was conducted in Sangkat TuekVil,KrongSiem Reap,in Cambodia.A 2×4 factorial in RCBD(Randomized Complete Blocks Design)was used to layout the trial,in which two varieties(Texas Early Grano 502 PRR and Earth F1)and four mulch types(non-mulch,rice Straw,silver plastic mulching and black plastic mulching)were used as the treatments.Application of these treatments was to enhance soil temperature,leaf number plant-1,stand count,bulb diameter,single bulb weight,insect incidence,disease incidence and bulb yield are different to all treatments.As the result,the bulb yields of onions among these treatments were found superior in Texas Early Grano 502 PRR combined with Black Plastic mulch followed by Texas Early Grano 502 PRR combined with silver plastic mulch and Texas Early Grano 502 PRR combined rice straw mulch,whereas the lowest was found in Earth F1combined with non-mulch.展开更多
In green onion harvesting,the problems of easy dumping and low rate of clean digging can be encountered.In this paper,a kind of harvesting device for digging and pulling green onions,referred to simply as"the dev...In green onion harvesting,the problems of easy dumping and low rate of clean digging can be encountered.In this paper,a kind of harvesting device for digging and pulling green onions,referred to simply as"the device",was designed.The device mainly consists of a digging shovel,screen bars,clamping conveyor belt,etc.This paper focuses on the analysis of the model forces of green onions and soil in the two states of the onion digging process without dumping and clamping.The key factors affecting the model state of onions and soil were identified as:screen bar length l_(2),screen bar inclination angleβ,and pulling point position x.Based on the discrete element simulation technology of EDEM,the mechanism-crop-soil model was established,and a single-factor simulation test was conducted to determine the range of values for each factor.Taking the advantages of field test and three-factor five-level orthogonal experimental design,the parameter combinations of green onion harvesting operation evaluation indices were optimized,including a pulling point position of 166 mm,screen bar length of 242 mm,and screen bar inclination angle of 14°.As the results of the field test show,the harvester operation was stable without congestion or damage,the harvesting effect of green onions was improved,and the clean digging rate reached 100%,which meets the agronomic requirements for onion harvesting and the expectations of users.展开更多
In view of the problems of easy damage and high digging resistance in the process of green onion harvesting,a mechanical model of digging green onions was established by taking the moment of digging and drawing green ...In view of the problems of easy damage and high digging resistance in the process of green onion harvesting,a mechanical model of digging green onions was established by taking the moment of digging and drawing green onions as the research object,and the main factors affecting the digging and harvesting effect were determined as the angle of digging,the dip angle of clamping carrier and the length of shovel.Thus,a complex simulation model of soil-green onion-digging mechanism system reflecting the state of harvesting was established,and the model was verified by testing soil compactness.The simulation tests were carried out by means of the complex simulation model of soil-green onion-digging mechanism system,making it clear that digging angle and the length of shovel have a extremely significant impact on the digging resistance,and the dip angle of the clamping carrier had a significant impact on the digging resistance.Through target optimization,the optimal combination of digging parameters was obtained,namely,the digging angle of 20°,the dip angle of clamping carrier of 25°and the shovel length of 70 mm,with the digging resistance of 1394 N at this moment.The field digging resistance test has showed that the average digging resistance is 1543 N with the average clamping damage rate of 1.27%and the average clamping loss rate of 0.44%,which can meet the requirements of green onion harvesting.展开更多
We supercooled fresh-cut onion at−5℃ for 12 h.After supercooling,the electric impedance properties of the samples were evaluated by electrical impedance spectroscopy over the frequency range of 42 Hz−5 MHz.The time-t...We supercooled fresh-cut onion at−5℃ for 12 h.After supercooling,the electric impedance properties of the samples were evaluated by electrical impedance spectroscopy over the frequency range of 42 Hz−5 MHz.The time-temperature profiles of samples indicated that the freezing point and supercooling point were−2.3℃±0.7℃ and−6.9℃±1.0℃,respectively.The results indicated that 34 of the 36 supercooled samples exhibited a definite circular arc in the Cole-Cole plot,which suggested that the cell membrane remained intact during supercooling.In the other two samples which did not exhibit a definite circular arc,the cell membrane had sustained serious damage during supercooling.Furthermore,there was large difference in drip loss percentage between supercooled samples exhibited a definite circular arc in the Cole-Cole plot and samples not exhibiting a definite circular arc.Our results suggest that fresh-cut onions can be supercooled at−5℃.展开更多
Based on the achievement of local ecological geochemical survey,the selenium in surface layer soil of Zhangqiu green Chinese onion within production area is systematically studied in this study.And the ecological geoc...Based on the achievement of local ecological geochemical survey,the selenium in surface layer soil of Zhangqiu green Chinese onion within production area is systematically studied in this study.And the ecological geochemical characters of selenium both in surface layer soil and in green Chinese onions are analyzed,and the relationship between the selenium in plant and soil is discussed.The results show that soil in Zhangqiu is rich in selenium,and it is suitable to develop the selenium-rich green Chinese onion products.展开更多
[Objective] The curative effect of onion on bacterial rotted gill disease in grass carp was researched [Method] The combination method of taking medicine through oral and spraying was used to cure sick grass carp for ...[Objective] The curative effect of onion on bacterial rotted gill disease in grass carp was researched [Method] The combination method of taking medicine through oral and spraying was used to cure sick grass carp for 1 period of treatment in room under artificial conditions. [Result] Different concentrations of onion generated different cure rates. When the combination was adding 1.0% - 2.0% medicine into feed and spraying 2.0 g,/m3 - 5.0 g,/m3, the curative result was the best with cure rate was 70% -90% [ Conclusion] The onion was effective on curing bacterial rotted gill disease in grass carp and could be taken as curative medicine.展开更多
With Welsh Onion seeds employed as materials, effects of magnetized water on seed Germination were studied. The results showed the treatment of magnetized water soaking for 4 h promoted water absorption rate and amyla...With Welsh Onion seeds employed as materials, effects of magnetized water on seed Germination were studied. The results showed the treatment of magnetized water soaking for 4 h promoted water absorption rate and amylase ac- tivities of seeds significantly, which accelerated the transformation process of en- dosperm starch to soluble sugar, resulting in emergence of 36 hours in advance under low temperature condition. Germination rate and germination potential of magnetized water soaking were higher than the contrast by 6.7% and 10.0%, which helped cultivate vigorous seedling.展开更多
Nuclear bodies have long been noted in interphase nuclei of plant cells, but their structural component, origin and function are still unclear by now. The present work showed in onion cells the nuclear bodies appeared...Nuclear bodies have long been noted in interphase nuclei of plant cells, but their structural component, origin and function are still unclear by now. The present work showed in onion cells the nuclear bodies appeared as a spherical structure about 0.3 to 0.8 microm in diameter. They possibly were formed in nucleolus and subsequently released, and entered into nucleoplasm. Observation through cytochemical staining method at the ultrastructural level confirmed that nuclear bodies consisted of ribonucleoproteins (RNPs) and silver-stainable proteins. Immunocytochemical results revealed that nuclear bodies contained no DNA and ribosomal gene transcription factor (UBF). Based on these data, we suggested that nuclear bodies are not related to the ribosome or other gene transcription activities, instead they may act as subnuclear structures for RNPs transport from nucleolus to cytoplasm, and may also be involved in splicing of pre-mRNAs.展开更多
基金supported by National Natural Science Foundation of China (No. 51575389, 51761135106, 51511130074)National Key Research and Development Program of China (2016YFB1102203)State key laboratory of precision measuring technology and instruments (Pilt1705)
文摘Annealing nanodiamonds(ND) at high temperatures up to 1700 ℃ is a common method to synthesize carbon onions. The transformation from NDs to carbon onions is particularly interesting because of carbon onions' potential in the field of tribology and their application in ultra-charge/discharge devices. In this paper, a novel surface-enhanced Raman scattering technique that involves coating the sample with nanoscopic gold particles is proposed to characterize the NDs after different annealing treatments. Conventional Raman and surfaceenhanced Raman spectra were obtained, and the changes of peak parameters as the function of annealing temperature were evaluated. It was found that the widths of the D and the G peaks decreased with increasing annealing temperature, reflecting an improved order in the sp^2-hybridized carbon during the transformation from NDs to carbon onions. After annealing at 1700 ℃, the sp^2?carbon was highly ordered, indicating desirable electrical conductivity and lubricity. With increasing annealing temperature, the D peak showed a blue shift of almost30 cm^(-1), while the G peak merely shifted by 5 cm^(-1). For annealing temperatures above 1100 ℃, an increase of intensity ratio ID/IGwas observed. Compared to the uncoated area, red shifts of 0.5-2 cm^(-1) and of 5-9 cm^(-1) for the G and D peaks, respectively, were detected for the gold-coated area, which was due to the coupling of the plasmons and the phonons of the samples.
基金Item supported by the agricultural keyproject of science and technology commission of Shanghai (No.03319419)
文摘Microbial counts （total aerobic psychrotrophic count （TPC）, lactic acid bacteria （LAB）, coliforms, pseudomonads, yeasts） and sensory properties of sliced onions stored at different temperatures and air compositions were investigated. Microbial counts were fitted to the modified Gompertz equation and the growth parameters of microorganisms (the initial cell number （N0）, maximum cell number (Nmax), maximum specific growth rate (μmax), lag-phase （（λ）） were obtained as derived parameters. The relationships between growth parameters of microorganisms and the microbial or sensory shelf life were built. The results showed that microbial counts increased and sensory qualities decreased during storage. TPC was predominant bacteria associated with spoilage of sliced onions under tested temperatures and air conditions. High correlation coefficients （r） were found between the lag time （λ） of TPC, coliforms, pseudomonads, yeasts and the microbial or sensory shelf life. The correlations between microbial or sensory shelf life and μmax of five microorganisms were between -0.69 and -0.86. The initial microbial counts （N0） of five microorganisms strains only showed a little correlation, and the maximum microbial counts (Nmax) showed no obvious correlation with shelf life except for LAB and yeasts.
基金Supported by Scientific Research Foundation for Doctors of Qufu Normal University~~
文摘[Objective] This study aimed to compare the similarities and dissimilarities in karyotypes of purple and white onions,so as to lay foundation for further studying its genetic improvement and breeding more onion varieties.[Method] Sections of root-tip cells were prepared by normal wafer method.Photomicrography was adopted to produce the high-quality chromosome specimen.Finally,karyotype analysis was conducted using Adobe Photoshop.[Result] Chromosome karyotype analysis on the root-tip showed that the chromosome number of both purple and white onions was 2n=2x=16.Among the 16 chromosomes of both the onions,no satellite chromosome was found.By measuring and calculating,it was found that the karyotype of the studied white union belonged to the lowly evolutional 2A type,and its karyotype formula was 2n=2x=16=14 m ＋2St,with the karyotype asymmetry coefficient of 58.67%.No obvious centromere was observed in the sections of purple onion.[Conclusion] The karyotypes of white and purple unions are similar and we can infer from this fact that the reason of different characters between both the onions is not due to the chromosome aberration.This karyotype formula and asymmetrical karyotype coefficient have some reference values on the identification of onion variety resources.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2019YFE0122900)the National Natural Science Foundation of China(No 51971162,U1933112,51671146)+1 种基金China Postdoctoral Science Foundation(Grant No.2020M671208)Open access funding provided by Shanghai Jiao Tong University
文摘The rational construction of microstructure and composition with enhanced Maxwell-Wagner-Sillars effect(MWSE)is still a challenging direction for reinforcing electromagnetic wave(EMW)absorption performance,and the related EMW attenuation mechanism has rarely been elucidated.Herein,MWSE boostedβ-chitin/carbon nano-onions/Ni–P composites is prepared according to the heterointerface engineering strategy via facile layer-by-layer electrostatic assembly and electroless plating techniques.The heterogeneous interface is reinforced from the aspect of porous skeleton,nanomaterials and multilayer construction.The composites exhibit competitive EMW response mechanism between the conductive loss and the polarization/magnetic loss,as describing like the story of“The Hare and the Tortoise”.As a result,the composites not only achieve a minimum reflection loss(RL_(min))of−50.83 dB and an effective bandwidth of 6.8 GHz,but also present remarkable EMW interference shielding effectiveness of 66.66 dB.In addition,diverse functions such as good thermal insulation,infrared shielding and photothermal performance were also achieved in the hybrid composites as a result of intrinsic morphology and chemicophysics properties.Therefore,we believe that the boosted MWSE open up a novel orientation toward developing multifunctional composites with high-efficient EMW response and thermal management.
基金financially supported by the Special Fund for Agro-scientific Research in the Public Interest,China(20090318)the Yangzhou Agricultural Science and Technology Research Projects,China(YZ2014170)
文摘Onion（Allium cepa L.） is a very important vegetable crop widely cultivated throughout the world. In this study, we measured total anthocyanins and flavonols of onions of three colors. The fresh weight（FW） of total anthocyanins were（29.99±1.19）,（9.64±1.30） and（0.75±0.40） mg 100 g^–1 fruit in red, yellow and white onions, respectively. Likewise, the FW of total flavonoids were（111.10±5.98）,（36.64±3.59）, and 0 mg 100 g^–1 in red, yellow and white, respectively. Four types of anthocyanins（delphinidin 3,5-diglycosides, cyanidin 3,5-diglycosides, cyanidin 3-glycosides and cyanidin 3-（6′′-malonyl）-glucopyranoside） and two kinds of flavonoids（quercetin and quercetin 3-glycosides） were identified in two varieties（red and yellow bulb） of onions by HPLC/DAD-ESI/MS. The total polyphenol contents were also measured by means of Folin-Ciocalteu method. Moreover, all the concentrations of anthocyanins, flavonoids and polyphenols showed significantly positive correlations with antioxidant activities measured by DPPH˙, ABTS˙＋ and FRAP assays. This study provided information on anthocyanin and flavonoids compositions that will be useful for onion breeding.
基金Supported by the Scientific Research Projects of Basic Scientific Research Business Expenses of Undergraduate Universities in Heilongjiang Province(135309363)Fundamental Research Business Expenses of Heilongjiang Provincial Universities(Specialized Subjects of Plant Food Processing Technology)(YSTSXK201889)+2 种基金Heilongjiang General Undergraduate Universities Young Innovative Talents Training Plan(UNPYSCT-2018101)Natural Science Foundation of Heilongjiang Province(LH2019C067)Science and Technology Plan Project of Qiqihar City(NYGG-201915)。
文摘Onion(Allium cepa L.)is a common biennial herb,and contains allicin compounds which can kill harmful microorganism.The antibacterial effects of raw and mature onion juice of purple,yellow and white-skinned onions at different concentrations on Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were studied.There were differences among the antibacterial effects of raw and mature onion juice of purple,yellow and white-skinned onions at different concentrations.What was more,the antibacterial effects of raw onion juice were better than those of the mature one.The antibacterial effects of high concentration onion juice were better than those of the low one.The content of the total flavonoids in raw purple onion was higher than that in mature onion,and reached extremely significant levels in 50%,75%and 100%,respectively.Through comparison,it was found that onion juice of purple-skinned had the best suppression effects on S.aureus(gram-positive bacterium)and E.coli(gram-negative bacterium),and gram-positive bacterium had better suppression effects than gram-negative bacterium.It wound provide the basis about bioactive function and antibacterial drugs.
文摘The content of polyphenolic substances in commercial onions has been determined. The antioxidant activity of their ethanolic extracts, as well as their effects on the oxidation of edible corn oil during accelerated ageing was studied. Maceration of taxonomically identified commercial vegetable samples, previously peeled and thinly sliced, was carried out at ambient temperature, out of direct light, with occasional agitation and ultrasound, employing 95% ethyl alcohol as the extraction solvent, allowing them to stand for 7 days. The total polyphenolic contents were determined on the filtrated extracts using the Folin-Ciocalteau method. The antioxidant activity was evaluated on emulsions of ethanolic extracts of onion prepared in edible commercial corn oil, using sorbitan monooleate as emulsifying agent. The peroxide values were analyzed using the iodometric method;oxidation induction times were obtained from the peroxide evolution graphs, using the tan- gent method. Oil samples emulsified with ethanolic onion extracts showed an extension of the induction period. A 7-day ageing study at 45?C was additionally performed to determine the conjugated dienes on pure commercial corn oil and its emulsions by visible spectrophotometry. The spectral analysis showed an increase of the measured absorbancies in oil samples without additives and no change for the oils emulsified with onion extract. An increasing of diene values was observed for corn oil without additives during ageing;no changes in the value were observed in oils emulsified with onion extracts.
文摘This research was carried out to assess the effect of different varieties and mulching types on insect and disease infestation,and the yield of onions.The experiment was conducted in Sangkat TuekVil,KrongSiem Reap,in Cambodia.A 2×4 factorial in RCBD(Randomized Complete Blocks Design)was used to layout the trial,in which two varieties(Texas Early Grano 502 PRR and Earth F1)and four mulch types(non-mulch,rice Straw,silver plastic mulching and black plastic mulching)were used as the treatments.Application of these treatments was to enhance soil temperature,leaf number plant-1,stand count,bulb diameter,single bulb weight,insect incidence,disease incidence and bulb yield are different to all treatments.As the result,the bulb yields of onions among these treatments were found superior in Texas Early Grano 502 PRR combined with Black Plastic mulch followed by Texas Early Grano 502 PRR combined with silver plastic mulch and Texas Early Grano 502 PRR combined rice straw mulch,whereas the lowest was found in Earth F1combined with non-mulch.
基金supported by the Taishan Scholar Youth Expert Project(Grant No.tsqn202306243)the National Natural Science Foundation of China(Grants No.52275258 and No.51775290)the Open Fund of Collaborative Innovation Center for Shandong’s Main Crop Production Equipment and Mechanization(Grant No.SDXTZX-10).
文摘In green onion harvesting,the problems of easy dumping and low rate of clean digging can be encountered.In this paper,a kind of harvesting device for digging and pulling green onions,referred to simply as"the device",was designed.The device mainly consists of a digging shovel,screen bars,clamping conveyor belt,etc.This paper focuses on the analysis of the model forces of green onions and soil in the two states of the onion digging process without dumping and clamping.The key factors affecting the model state of onions and soil were identified as:screen bar length l_(2),screen bar inclination angleβ,and pulling point position x.Based on the discrete element simulation technology of EDEM,the mechanism-crop-soil model was established,and a single-factor simulation test was conducted to determine the range of values for each factor.Taking the advantages of field test and three-factor five-level orthogonal experimental design,the parameter combinations of green onion harvesting operation evaluation indices were optimized,including a pulling point position of 166 mm,screen bar length of 242 mm,and screen bar inclination angle of 14°.As the results of the field test show,the harvester operation was stable without congestion or damage,the harvesting effect of green onions was improved,and the clean digging rate reached 100%,which meets the agronomic requirements for onion harvesting and the expectations of users.
基金sponsored by the National Natural Science Foundation of China(Grant No.52275258)Taishan Scholar Youth Expert Project,Qingdao City Science and Technology to Benefit the People Demonstration and Guidance Special Project(Grant No.22-3-7-xdny-14-nsh)the National Natural Science Foundation of China(Grant No.51775290).
文摘In view of the problems of easy damage and high digging resistance in the process of green onion harvesting,a mechanical model of digging green onions was established by taking the moment of digging and drawing green onions as the research object,and the main factors affecting the digging and harvesting effect were determined as the angle of digging,the dip angle of clamping carrier and the length of shovel.Thus,a complex simulation model of soil-green onion-digging mechanism system reflecting the state of harvesting was established,and the model was verified by testing soil compactness.The simulation tests were carried out by means of the complex simulation model of soil-green onion-digging mechanism system,making it clear that digging angle and the length of shovel have a extremely significant impact on the digging resistance,and the dip angle of the clamping carrier had a significant impact on the digging resistance.Through target optimization,the optimal combination of digging parameters was obtained,namely,the digging angle of 20°,the dip angle of clamping carrier of 25°and the shovel length of 70 mm,with the digging resistance of 1394 N at this moment.The field digging resistance test has showed that the average digging resistance is 1543 N with the average clamping damage rate of 1.27%and the average clamping loss rate of 0.44%,which can meet the requirements of green onion harvesting.
基金This work was supported by JSPS KAKENHI,grant number JP16H05001[Grant-in-Aid for Scientific Research(B)]JP16K15010[Grant-in-Aid for Exploratory Research].
文摘We supercooled fresh-cut onion at−5℃ for 12 h.After supercooling,the electric impedance properties of the samples were evaluated by electrical impedance spectroscopy over the frequency range of 42 Hz−5 MHz.The time-temperature profiles of samples indicated that the freezing point and supercooling point were−2.3℃±0.7℃ and−6.9℃±1.0℃,respectively.The results indicated that 34 of the 36 supercooled samples exhibited a definite circular arc in the Cole-Cole plot,which suggested that the cell membrane remained intact during supercooling.In the other two samples which did not exhibit a definite circular arc,the cell membrane had sustained serious damage during supercooling.Furthermore,there was large difference in drip loss percentage between supercooled samples exhibited a definite circular arc in the Cole-Cole plot and samples not exhibiting a definite circular arc.Our results suggest that fresh-cut onions can be supercooled at−5℃.
基金Supported by China Geological Survey Bureau Project(1212010310306)~~
文摘Based on the achievement of local ecological geochemical survey,the selenium in surface layer soil of Zhangqiu green Chinese onion within production area is systematically studied in this study.And the ecological geochemical characters of selenium both in surface layer soil and in green Chinese onions are analyzed,and the relationship between the selenium in plant and soil is discussed.The results show that soil in Zhangqiu is rich in selenium,and it is suitable to develop the selenium-rich green Chinese onion products.
基金The Natural Science Project of Xichang College(xA0509)~~
文摘[Objective] The curative effect of onion on bacterial rotted gill disease in grass carp was researched [Method] The combination method of taking medicine through oral and spraying was used to cure sick grass carp for 1 period of treatment in room under artificial conditions. [Result] Different concentrations of onion generated different cure rates. When the combination was adding 1.0% - 2.0% medicine into feed and spraying 2.0 g,/m3 - 5.0 g,/m3, the curative result was the best with cure rate was 70% -90% [ Conclusion] The onion was effective on curing bacterial rotted gill disease in grass carp and could be taken as curative medicine.
基金Supported by China Spark Program for Science and Technology(2011GA740072)Shandong Provincial Soft Scientific Research Project(2015RKC35001)Shandong Provincial Agricultural High-quality Seed Engineering(2016LZGC019)~~
文摘With Welsh Onion seeds employed as materials, effects of magnetized water on seed Germination were studied. The results showed the treatment of magnetized water soaking for 4 h promoted water absorption rate and amylase ac- tivities of seeds significantly, which accelerated the transformation process of en- dosperm starch to soluble sugar, resulting in emergence of 36 hours in advance under low temperature condition. Germination rate and germination potential of magnetized water soaking were higher than the contrast by 6.7% and 10.0%, which helped cultivate vigorous seedling.
文摘Nuclear bodies have long been noted in interphase nuclei of plant cells, but their structural component, origin and function are still unclear by now. The present work showed in onion cells the nuclear bodies appeared as a spherical structure about 0.3 to 0.8 microm in diameter. They possibly were formed in nucleolus and subsequently released, and entered into nucleoplasm. Observation through cytochemical staining method at the ultrastructural level confirmed that nuclear bodies consisted of ribonucleoproteins (RNPs) and silver-stainable proteins. Immunocytochemical results revealed that nuclear bodies contained no DNA and ribosomal gene transcription factor (UBF). Based on these data, we suggested that nuclear bodies are not related to the ribosome or other gene transcription activities, instead they may act as subnuclear structures for RNPs transport from nucleolus to cytoplasm, and may also be involved in splicing of pre-mRNAs.
