期刊文献+
共找到1,920篇文章
< 1 2 96 >
每页显示 20 50 100
Exploration on Management Measures of Onion Production in Eastern Henan Province
1
作者 Zhaojie XIAO 《Agricultural Biotechnology》 2024年第2期5-7,共3页
In this paper, the management points and cultivation difficulties of onion in different stages were discussed in detail from the aspects of onion cultivation seasons, cultivation methods, sowing and seedling raising, ... In this paper, the management points and cultivation difficulties of onion in different stages were discussed in detail from the aspects of onion cultivation seasons, cultivation methods, sowing and seedling raising, proper planting, field water and fertilizer management, stalk removal period, pest control, timely harvest and so on. This paper provides theoretical guidance for the high quality and high yield of onion in Huang-Huai area and data reference for further improvement of high-yielding onion cultivation technique system. 展开更多
关键词 onion CULTIVATION Huang-Huai area
下载PDF
The Role of Jasmonates as Antibulbing Substances in the Bulb Formation of Onion
2
作者 Noboru Takada Atsushi Saito +4 位作者 Yuuki Matsuzuka Tatsushi Mochiduki Eriko Wakita Meng WANG Yasunori Koda 《Agricultural Biotechnology》 2024年第1期1-4,8,共5页
Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extract... Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation. 展开更多
关键词 onion(Allim cepa L.cv.Higuma) ISOLATION Bulb formation Antibulbing substance α-Linolenic acid Methyl jasmonate
下载PDF
Influence of Microorganisms Effective against Basal Rot and on Agronomic Parameters of Onion [Allium cepa L. (Amaryllidaceae)]
3
作者 Henriette Doukahonon Guigui Bi Zaï Pacôme Zaouli +1 位作者 Alain Serge Coulibaly Juliette Ky Dedi 《Journal of Agricultural Chemistry and Environment》 2024年第3期282-299,共18页
Onions are a horticultural crop of great economic, dietary and medicinal importance, and are highly prized by the Ivorian population. However, production remains low, due to a number of constraints, including parasiti... Onions are a horticultural crop of great economic, dietary and medicinal importance, and are highly prized by the Ivorian population. However, production remains low, due to a number of constraints, including parasitic attacks. The most frequent is fusariosis caused by Fusarium sp., a pathogen that causes enormous damage to onion crops. Faced with these attacks, chemical control appears to be ineffective, with consequences for human health and the environment. This is why the search for effective alternative methods that respect the environment and human health is so necessary. It is in this context that this study was carried out, with the general aim of controlling fusarium wilt in onion crops, with a view to improving onion production in Ivory Coast through the use of effective microorganisms. The experimental set-up used for this purpose was a fisher block with complete randomization, comprising three replicates. A fungal spore concentration of 106 spore/mL of Fusarium sp., three doses (1%;2.5% and 5% v/v) of EM and one dose of a chemical fungicide (30 mL/16L) were tested on young onion plants. Each block consisted of nine sub-plots with nine treatments. Health parameters (incidence and severity) and agronomic parameters (growth and yield) were assessed. Microbiological analysis of the EM revealed the presence of nine morphotypes of Trichoderma sp., Aspergillus clavatus, Aspergillus flavus, Aspergillus sp., Penicillium sp., Rhizopus sp., lactic acid bacteria of the Bacillus family and the yeast Saccharomyces cerevisiae. Field experimentation showed that the 5% EM microbial solution reduced the incidence and severity of fusariosis compared with the chemical fungicide, and proved to be the best. This dose reduced yield losses by 7.14%, while improving onion growth and yield by over 5%. The results demonstrated the ability of the EM solution to effectively control the causal agent of basal rot in onion crops. 展开更多
关键词 Basal Rot Effective Microorganisms (EM) Fusarium sp. onion
下载PDF
On the “Onion Husk” Algorithm for Approximate Solution of the Traveling Salesman Problem
4
作者 Mikhail E. Abramyan Nikolai I. Krainiukov Boris F. Melnikov 《Journal of Applied Mathematics and Physics》 2024年第4期1557-1570,共14页
The paper describes some implementation aspects of an algorithm for approximate solution of the traveling salesman problem based on the construction of convex closed contours on the initial set of points (“cities”) ... The paper describes some implementation aspects of an algorithm for approximate solution of the traveling salesman problem based on the construction of convex closed contours on the initial set of points (“cities”) and their subsequent combination into a closed path (the so-called contour algorithm or “onion husk” algorithm). A number of heuristics related to the different stages of the algorithm are considered, and various variants of the algorithm based on these heuristics are analyzed. Sets of randomly generated points of different sizes (from 4 to 90 and from 500 to 10,000) were used to test the algorithms. The numerical results obtained are compared with the results of two well-known combinatorial optimization algorithms, namely the algorithm based on the branch and bound method and the simulated annealing algorithm. . 展开更多
关键词 Branch and Bound Method Contour Algorithm onion Husk” Algorithm Simulated Annealing Method Traveling Salesman Problem
下载PDF
Morpho-Molecular Characterization of Ditylenchus dipsaci and Alternatives for Its Management in Green Onion Allium fistulosum Crops from Colombia
5
作者 Donald Riascos-Ortiz Jean Caicedo-Castro +3 位作者 Carlos Arboleda-Riascos Francisco Sánchez Ana T. Mosquera-Espinosa Francia Varón De Agudelo 《Agricultural Sciences》 2023年第11期1516-1534,共19页
Green onion is one of the most consumed vegetables in Colombia. However, its production is negatively affected by the nematode Ditylenchus. To determine the species of the nematode, as well as to propose management st... Green onion is one of the most consumed vegetables in Colombia. However, its production is negatively affected by the nematode Ditylenchus. To determine the species of the nematode, as well as to propose management strategies for its control, in the present study the morphological, morphometric, and molecular characterization of the phytonematode was carried out and was used to evaluate the effect of immersion of the propagation material in water hot, application of a commercial strain of Purpureocillium lilacinum and the application of an agrochemical with insecticidal-nematicidal action to control the phytosanitary problem under field conditions. The morphological and morphometric characteristics of the nematode were similar to those reported for the type and reference populations of D. dipsaci. Based on sequences of the D2-D3 segment and Internal Transcribed Spacer-ITS of the rRNA, the presence of D. dipsaci in green onion crops in Colombia was confirmed. The application of P. lilacinum statistically showed an efficient control of D. dipsaci, at the same time that presented the highest yield, in relation to the other evaluated treatments (P ≤ 0.05). 展开更多
关键词 onion Rot Stem and Bulb Nematode D2-D3 ITS Purpureocillium lilacinum
下载PDF
Karyotype Comparison and Analysis on Different Kinds of Onions 被引量:1
6
作者 陈蕾 王军 《Agricultural Science & Technology》 CAS 2011年第12期1807-1809,共3页
[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
关键词 Purple onion White onion Chromosome sectioning KARYOTYPE
下载PDF
Ecological Geochemistry of Selenium in the Production Base of Zhangqiu Green Chinese Onion 被引量:3
7
作者 庞绪贵 高宗军 +1 位作者 王敏 王增辉 《Agricultural Science & Technology》 CAS 2010年第11期39-43,共5页
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
关键词 Ecological geochemistry Zhangqiu green Chinese onion Selenium-rich agricultural products Available selenium Biological accumulation coefficient
下载PDF
The Therapeutic Effect of Onion on the Pathogenic Bacteria of Gill Rot Disease in Grass Carp 被引量:2
8
作者 徐大勇 韦汉群 张文丽 《Agricultural Science & Technology》 CAS 2008年第1期117-120,共4页
[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
关键词 onion Bacterial rotted gill disease Oral method Spraying method Grass carp
下载PDF
Effects of Magnetized Water on Seed Germination of Welsh Onion (Allium fistulosum L.) 被引量:2
9
作者 苗锦山 王树勇 游海英 《Agricultural Science & Technology》 CAS 2017年第5期777-779,784,共4页
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
关键词 Magnetized water Welsh onion Seed germination Germination rate Germination potential
下载PDF
“ONION”式英语阅读探微
10
作者 邵朝霞 邵琴香 《煤炭高等教育》 2002年第1期103-104,共2页
利用“ONION”的构造原理分析了英语预读和阅读正文过程中围绕中心逐层分剥式全面、准确、深层理解读物内容和技巧 。
关键词 onion”式 英语阅读 大学英语 阅读水平 阅读理解
下载PDF
Effect of Natural Infection with Onion Yellow Dwarf Virus (OYDV) on Yield of Onion and Garlic Crops in Egypt
11
作者 Salah Elnagar Mohamed Abdel-Kader El-Sheikh Abeer Salah E1-Deen Abd E1-Wahab 《Journal of Life Sciences》 2011年第8期634-638,共5页
Present work highlights, first time in Egypt, the impact of OYDV infection on crops production. Plants grown in the field were individually labelled as either apparently healthy or diseased and were marked for harvest... Present work highlights, first time in Egypt, the impact of OYDV infection on crops production. Plants grown in the field were individually labelled as either apparently healthy or diseased and were marked for harvesting. The percentage of yield loss due to viral infection was determined, on the basis of the average yield parameters of the healthy plant. The natural infection with OYDV in onion and garlic fields resulted in a substantial reduction in pseudo-stem length, number of leaves, plant weight and weight of bulb as well as number and weight of cloves. Results clearly indicate the impact of natural infection with OYDV on the crop yield of infected onion and garlic plants in comparison with the virus-free (uninfected) ones. The largest reduction in the yield of infected plants occurred in Chinese garlic (Seds40) followed by (Baladi) garlic and onion Giza 20. This information suggests that measures have to be taken to prevent natural infection with OYDV into and within onion and garlic fields in order to avoid yield loss. 展开更多
关键词 onion yellow dwarf virus (OYDV) yield reduction onion garlic.
下载PDF
Physiological Changes in Red Onion Bulbs at Different Storage Temperature
12
作者 Mouluda Sohany Md. Kamal Uddin Sarker Md. Sultan Mahomud 《World Journal of Engineering and Technology》 2016年第2期261-266,共6页
Onion bulbs were stored at five different temperatures to know the storage behavior of onion bulbs. Indian red onion bulbs were kept without wrapping at ambient conditions (25℃ ± 3℃ and 75% RH) and within polye... Onion bulbs were stored at five different temperatures to know the storage behavior of onion bulbs. Indian red onion bulbs were kept without wrapping at ambient conditions (25℃ ± 3℃ and 75% RH) and within polyethylene pouch at 2.5℃, 6℃, 7℃ and 13℃ for 60 days of storage period. Weight loss, total soluble solids (TSS), number of sprouted and rotten bulbs were measured at an interval of 10 days throughout storage. The greatest decrease (23.25%) in weight was observed throughout storage for onions stored at ambient conditions. TSS was observed to increase in all samples until 40 days of storage and then decreased up to 60 days. Lowest TSS (14.89 ?Bx) was found in onion stored at ambient conditions at the end of storage. Maximum sprouted (67.25%) and rotten (17.78%) onions were observed for onions stored at 13℃, whereas minimum sprouted and rotten onions were found at 2.5℃ at 60 days of storage. Results also recommend lowest temperatures (2.5℃ - 6℃) for prolong storage life of onion with no detrimental effects. 展开更多
关键词 onion onion Bulb Allium cepa PHYSIOLOGICAL Storage Behavior
下载PDF
Infrared Spectroscopic Study of Fistular Onion (Allium fistulosum) and Garlic (Allium sativum) Rust Leaves
13
作者 何志遥 刘海丽 +4 位作者 吴秋娟 周湘萍 刘刚 董勤 俞帆 《Plant Diseases and Pests》 CAS 2011年第4期21-23,共3页
[ Objective] Fourier transform infrared spectroscopy was used to study fistular onion (Alliumfistulosum) and garlic (Allium sativum) rust leaves, so as to explore the application potential of mid-infrared spectros... [ Objective] Fourier transform infrared spectroscopy was used to study fistular onion (Alliumfistulosum) and garlic (Allium sativum) rust leaves, so as to explore the application potential of mid-infrared spectroscopy in the diagnosis of crop disease. [ Method] The normal green leaves and rust leaves of fistular onion and garlic were tested using fourier transform infrared spectroscopy, and their spectral differences were analyzed. [ Result] The infrared spectra of green leaves of fistular onion and garlic are mainly composed of the vibrational bands of polysaccharides, protein and ester. Normal and rust leaves exhibited differences in the fin- gerprint interval of 1 800 -900 cm-1 , in which the band at 1 640 cm-1 in the spectrum of flstular onion rust leaf became stronger, and the band at 1 103 cm-1 was not obvious compared with the spectrum of normal leaf. The absorbance ratios A1640/A1063, A1640/A1736, A1640/A2924, and A1063/A2924 of onion rust leaf were larger than the corresponding ratios A1638/A1 059, A1738/A1 38, A2921/A1638, and A2 92l/A1059 in the spectrum of normal leaf. The band of polysaccharides at 1 056 cm-1 in the spectrmn of garlic normal leaf was the strongest in fingerprint area, while the band at 1 634 cm-1 in the spectrum of garlic rust leaf was the strongest in that are- a. The absorbance ratios A1634/A1069 , A1634/A1099 , A1409/A2923 , and A1634/A737 of garlic rust leaf were larger than the corresponding ratios A1627/A1056 , A1623/A1104 , A1411/A2920 and A1627/A1740 of normal leaves. While the ratios A1634/A2923, A1059/A2923, and A1737/A2923 of garlic rust leaf were less than the corresponding values of A1627/A2920, A1056/A2920, and A1 740/A2920 of normal leaf. [ Conclusion] Rust leaf and normal leaf could be distinguished according to the differences in infrared spectra, and infrared spectroscopy could be developed as the detection method for crop diseases. 展开更多
关键词 Fistular onion leaf Garlic leaf Rust disease Fourier transform infrared spectroscopy China
下载PDF
Heterointerface Engineering of β‑Chitin/Carbon Nano‑Onions/Ni-P Composites with Boosted Maxwell‑Wagner‑Sillars Effect for Highly Efficient Electromagnetic Wave Response and Thermal Management 被引量:7
14
作者 Fei Pan Lei Cai +7 位作者 Yuyang Shi Yanyan Dong Xiaojie Zhu Jie Cheng Haojie Jiang Xiao Wang Yifeng Jiang Wei Lu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第5期206-223,共18页
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
关键词 β-chitin Nano onion carbon Electromagnetic wave absorption Electromagnetic interference shielding Photothermal
下载PDF
Quantification and analysis of anthocyanin and flavonoids compositions,and antioxidant activities in onions with three different colors 被引量:27
15
作者 ZHANG Shi-lin DENG Peng +2 位作者 XU Yu-chao Lü Shan-wu WANG Jian-jun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第9期2175-2181,共7页
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
关键词 onion(Allium cepa L.) anthocyanins flavonoids antioxidant activity HPLC-DAD-ESI/MS
下载PDF
Separation and Identification of Flavonoids from Fistular Onion Stalk(Allium fisturosum L.var.Caespitosum Makio) 被引量:3
16
作者 付琴琴 刘静幽 +4 位作者 张长弓 周银波 张耕 马丹 杨新洲 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2010年第2期255-257,共3页
The chemical constituents of fistular onion stalk obtained by supercritical CO2 extraction were separated and purified by silica gel and sephadex LH-20 gel column chromatography and the preparative TLC method and four... The chemical constituents of fistular onion stalk obtained by supercritical CO2 extraction were separated and purified by silica gel and sephadex LH-20 gel column chromatography and the preparative TLC method and four flavonoids were obtained. On the basis of the spectral data, they were structurally identified as (+)-catechin, (-)-epieatechin, astragalin, and 3-O-β-D(2-O-β-D-glu- copyranosyl)-glucopyranosides of kaempferol. 展开更多
关键词 fistular onion stalk allium fisturosum supercritical CO2 extraction chemical constituents FLAVONOIDS
下载PDF
Effect of onion (<i>Allium cepa</i>L.) as an antibiotic growth promoter substitution on performance, immune responses and serum biochemical parameters in broiler chicks 被引量:3
17
作者 Majid Goodarzi Nasir Landy Shahram Nanekarani 《Health》 2013年第8期1210-1215,共6页
This experiment was conducted to evaluate the effect of onion (Allium cepa L.) as an antibiotic growth promoter substitute on growth performance, immune responses and serum biochemistry in broilers. A total of 192 one... This experiment was conducted to evaluate the effect of onion (Allium cepa L.) as an antibiotic growth promoter substitute on growth performance, immune responses and serum biochemistry in broilers. A total of 192 one-d-old as hatched broiler chicks (Ross 308) were weighed and randomly allocated to four treatment groups, each with 4 replicate pens of 12 chicks. The dietary treatments consisted of the basal diet (control), antibiotic (15 mg Virginiamycin/kg), and control +10 or 30 g fresh onion bulb/kg diet. Body weights of broilers were determined at d 1, 21 and 42, feed intake was determined at the same periods, and feed conversion ratio was calculated accordingly. At 14th and 21st days blood samples were taken for measuring antibody titers against NDV and at 42nd day for biochemical analysis. At d 42, two birds per replicate were slaughtered for determination of lymphoid organ weights. Dietary supplementation of30 g/kg onion increased final body weight of broilers at 42nd d of age compared to the other treatments (P < 0.05). Birds fed30 gonion/kg in the diet had the highest feed intake than other treatments at different growth periods (P < 0.05). Dietary treatments failed to induce any significant effect on antibody titers against NDV, although the weight of lymphoid organs was significantly (P Broilers receiving30 g/kg onion had a significantly higher HDL and lower triglyceride concentrations compared to control groups (P . Feeding30 g/kg onion resulted in a marked reduction in the concentration of the glucose compared to control groups (P . The results suggested that dietary inclusion of30 g/kg onion can be applied as alternatives to in-feed antibiotics for broiler diets. 展开更多
关键词 ALLIUM cepa onion Broiler CHICKENS Immune Response SERUM Biochemical Parameters
下载PDF
Investigation of weld parameters on ductility, onion ring and fracture behaviour of friction stir welded AA2219-T87 被引量:2
18
作者 Dinesh KUMAR R S MUTHUKUMARAN +2 位作者 Vincent XAVIER T VENKATESWARAN D SIVAKUMAR 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第9期2318-2327,共10页
Friction stir welding provides better retention of ductility and plasticity in comparison to fusion welding and it increases the stability against cracking.This study aims to enhance both the ductility and strength of... Friction stir welding provides better retention of ductility and plasticity in comparison to fusion welding and it increases the stability against cracking.This study aims to enhance both the ductility and strength of the welded joints.Tool profile was found to play an important role in retaining ductility,understanding the metal flow behavior and determining the fracture initiating point.The microstructure of different regions in the onion ring was inferred to correlate the strength with the metal flow pattern.The onion ring pattern strengthened the weld nugget.Shoulder and taper threaded profile tool resulted in superior mechanical properties.Microhardness results confirmed that the fracture runs through low hardness areas such as heat affected zone and thermo-mechanically affected zone.The scanning electron microscopic images revealed elongated grains and dimples,justifying ductile mode of fracture. 展开更多
关键词 plasticity metal flow onion ring fracture friction stir welding
下载PDF
Synthesis of highly fluorescent carbon dots from lemon and onion juices for determination of riboflavin in multivitamin/mineral supplements 被引量:5
19
作者 Severino S. Monte-Filho Stefani I.E. Andrade +1 位作者 Marcelo B. Lima Mario C.U. Araujo 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2019年第3期209-216,共8页
In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluo... In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (CDs). The structure and optical properties of CDs were investigated by TEM, XRD, XRF, UV-Vis, FTIR, and fluorescence spectroscopy. CDs displayed satisfactory optical pro-prieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the CDs and riboflavin was achieved with CDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 μg/mL was observed, allowing the development of an accurate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, CDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and <2.6% (n = 3), respectively. CDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of CDs and determination of riboflavin. 展开更多
关键词 Carbon dots Microwave-assisted CARBONIZATION Lemon-onion JUICE RIBOFLAVIN Multivitamin/mineral SUPPLEMENTS Fluorescence
下载PDF
Effect of Ni,Fe and Fe-Ni alloy catalysts on the synthesis of metal contained carbon nano-onions and studies of their electrochemical hydrogen storage properties 被引量:5
20
作者 Chenguang Zhang Jiajun Li +3 位作者 Chunsheng Shi Chunnian He Enzuo Liu Naiqin Zhao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第3期324-330,共7页
Three types of carbon nano-onions(CNOs) including Ni@CNOs.Fe3C@CNOs and Fe0.64Ni0.36@CNOs nanoparticles have been synthesized by catalytic decomposition of methane at 850 ℃ using nickel,iron and iron-nickel alloy c... Three types of carbon nano-onions(CNOs) including Ni@CNOs.Fe3C@CNOs and Fe0.64Ni0.36@CNOs nanoparticles have been synthesized by catalytic decomposition of methane at 850 ℃ using nickel,iron and iron-nickel alloy catalysts.Comparative and systematic studies have been carried out on the morphology,structural characteristics and graphitic crystallinity of these CNOs products.Furthermore,the electrochemical hydrogen storage properties of three types of CNOs have been investigated.Measurements show that the Ni@CNOs have the highest discharge capacity of 387.2 mAh/g,coiTesponding to a hydrogen storage of 1.42%.This comparison study shows the advantages of each catalyst in the growth of CNOs.enabling the controllable synthesis and tuning the properties of CNOs by mediating different metals and their alloy for using in the fuel cell system. 展开更多
关键词 carbon nano-onion NICKEL iron iron-nickel alloy electrochemical hydrogen storage property
下载PDF
上一页 1 2 96 下一页 到第
使用帮助 返回顶部