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生成式人工智能赋能本科生科研能力培养——ChatGPT支持的CUREs教学模式 被引量:1
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作者 吴忭 李凤鸣 胡艺龄 《现代远程教育研究》 CSSCI 北大核心 2024年第3期3-10,28,共9页
为促进高等教育中高素质创新人才培养,构建以学生为中心的科研训练与课程教学整合模式是有效途径。当前基于课程的本科生科研体验(CUREs)教学模式虽在增强学生对科学本质的理解等方面具有一定优势,但在激发学生研究动机方面存在一些不... 为促进高等教育中高素质创新人才培养,构建以学生为中心的科研训练与课程教学整合模式是有效途径。当前基于课程的本科生科研体验(CUREs)教学模式虽在增强学生对科学本质的理解等方面具有一定优势,但在激发学生研究动机方面存在一些不足。将支持高效反馈的生成式人工智能ChatGPT引入人机协作研究过程中,有助于改善学生的科研体验,推动科研项目化学习。通过对ChatGPT支持的CUREs教学模式的设计与实施,发现该模式有助于培养学生的科研能力,提升他们的科研知识水平、科研技能水平和科研情感水平。尽管学生认同该教学模式的有效性和易用性,但其实际效果的发挥仍需人类智慧的参与。未来需要持续升级和优化生成式人工智能技术,确保技术应用高效且符合伦理标准;应用生成式人工智能技术重构教学模式,并通过长周期、跨场域实践检验其应用效果;强调人工智能与人类智慧的互补协作,真正实现生成式人工智能赋能学生科研能力提升。 展开更多
关键词 生成式人工智能 ChatGPT 科研能力 CUREs 教学模式
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Study on Loading Leaves Density with Cage Clamp on Quality of Cured Tobaccos in Bulk-Curing Barn
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作者 王能如 余金恒 +2 位作者 罗荣欣 林北森 尹永强 《Agricultural Science & Technology》 CAS 2014年第8期1317-1321,共5页
In order to determine the best loading density of tobacco leaf with cage clamp in bulk-curing barns, a curing test was conducted on middle-part tobacco leaves. The results showed that for good appearance quality of cu... In order to determine the best loading density of tobacco leaf with cage clamp in bulk-curing barns, a curing test was conducted on middle-part tobacco leaves. The results showed that for good appearance quality of cured tobacco, the loading density at 59.52 kg/m2 (4 000 kg/barn) was the best, fol owed by 66.96 kg/m2 (4 500 kg/barn) and 74.40 kg/m2 (5 000 kg/barn). As leaf loading density increased, the contents of leaf nicotine and total nitrogen increased, sugar content had smal changes, the ratio of sugar to nicotine decreased and tended to be balanced and the content of neutral aroma substances was decreasing, but the difference among treatments was not significant. With the increase of loading density, the sensory quality of cured leaf was better. When leaf loading density was 66.96 kg/m2 (4 500 kg/barn), apperance quality of cured leaf improved considerably, with prominent aro-ma. Therefore, the best loading density of tobacco leaf in cage clamp of bulk-curing barn would be 66.96 kg/m2 (4 500 kg/barn) . 展开更多
关键词 Flue-cured tobacco Bulk curing Tobacco quality Cage clamp Loadingleaves density
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Curing Characteristics and Suitable Harvest Maturity of Fresh Flue-cured Tobacco Leaves in Ankang Tobacco Growing Areas 被引量:2
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作者 朱峰 饶智 +3 位作者 沈始权 孙福山 任杰 肖头杰 《Agricultural Science & Technology》 CAS 2015年第4期815-819,共5页
CuItivars K326, Yunyan 87 and Guiyan 4 were used to investigate the curing characteristics and suitabIe harvest maturity of fresh fIue-cured tobacco Ieaves in Ankang tobacco growing areas. ResuIts indicated that the w... CuItivars K326, Yunyan 87 and Guiyan 4 were used to investigate the curing characteristics and suitabIe harvest maturity of fresh fIue-cured tobacco Ieaves in Ankang tobacco growing areas. ResuIts indicated that the water Ioss of K326 was sIow,and the Ieaves were resistant to curing and reIative easiIy to cure. The water Ioss of Yunyan 87 and Guiyan 4 were quick, and the Ieaves with normal resistance to curing were reIative difficuIt to cure. For Guiyan 4, the shrinkage of CM1 maturity was the Iargest. For K326 and Yunyan 87, the shrinkages of CM2 maturity were the Iargest whiIe the shrinkage of CM1 maturity was the Iowest, but the difference did not reach statistical significance. The proportion of top-middIe-grade tobacco Ieaves and average price for K326 were the highest with XM2, CM2 and BM2 maturity, and for Yunyan 87 were XM1, CM3 and BM2 maturity. For K326, Ieaves with XM2, CM2 and BM2 maturity showed the balanced chemical components and the best smoking quality. 展开更多
关键词 FIue-cured tobacco curing characteristic MATURITY Ankang City of Shaanxi Province
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Effects of Two Curing Methods on Quality of Yellow Sun-cured Tobacco 被引量:1
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作者 王毅 兰应海 +6 位作者 杨光辉 谢丽华 柴家荣 李光西 屈生彬 张晨东 钱颖颖 《Agricultural Science & Technology》 CAS 2012年第10期2097-2100,共4页
[Objective] The aim was to research effects of bamboo split curing method and steely barn curing method on quality of yellow sun-cured tobacco, providing scientific references for optimization of curing technology of ... [Objective] The aim was to research effects of bamboo split curing method and steely barn curing method on quality of yellow sun-cured tobacco, providing scientific references for optimization of curing technology of yellow sun-cured tobacco. [method] The tobaccos were divided into two groups treated with two methods and the related indices of treated tobaccos were then measured to evaluate effects of curing methods on quality of yellow sun-cured tobacco. [Result] Tobaccos treated with two methods were all dominated by reddish yellow and yellow; exterior quality differed little. In detail, total sugar and reducing sugar in an average level in three locations were all higher with method A than those with method B, but nicotine and total N were lower; comprehensive chemical components in group with method B proved more appropriate with higher K. In addition, sensory qualities of leaves in moderate and bottom locations were better with method B compared with method A; sensory quality of top leaves was better; comprehensive sensory quality of leaves treated with method B proved better. On the other hand, cost for method A was 2.82 times of method B; the area of sun-curing field was 3.27 times and manage- ment work was 1.77 times, which indicated that method B is low-cost and time-saving, which would be a guarantee of tobacco quality. [Conclusion] The research provides scientific references for rational use of tobacco resources and optimization of sun-curing technology. 展开更多
关键词 Yellow-sun-cured tobacco curing method Chemical component Sensory quality
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Effects of Different Flue-curing Barns on Aroma Quality of Upper Flue-cured Tobacco Leaves of K326 被引量:2
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作者 詹军 周芳芳 +4 位作者 徐成龙 张晓龙 王柱石 陈初 朱海滨 《Agricultural Science & Technology》 CAS 2014年第11期2014-2019,共6页
[Objective] This study was conducted to compare the aroma quality of up-per leaves of K326 flue-cured in different barns, and provide theoretical references for the development and optimization of bulk curing barn and... [Objective] This study was conducted to compare the aroma quality of up-per leaves of K326 flue-cured in different barns, and provide theoretical references for the development and optimization of bulk curing barn and the supporting tech-niques. [Method] The upper leaves of K326 were flue-cured in a commonness barn, a four-shelf bulk curing barn and a three-shelf bulk curing barn separately, and then the contents of aroma components and taste quality indices of the finished leaves were measured and compared. [Result] The contents of total aroma components, chromoplast pigment degradation products, phenylalanine aroma components and neophytadiene showed no significant differences in the leaves flue-cured in four-shelf bulk curing barn and commonness barn, but were significantly or very significantly higher than those in the leaves flue-cured in three-shelf bulk curing barn. The con-tents of carotenoid degradation products, Mail ard reaction products, cembranes aro-ma components and total aroma components (except neophytadiene) showed no significant difference among the three treatments. The results of sensory evaluation revealed that the sensory taste of the leaves flue-cured in four-shelf bulk curing barn was the best, as the finished leaves had rich, delicate aroma, comfortable and clean aftertaste. The leaves flue-cured in commonness barn was better than those flue-cured in three-shelf bulk curing barn in aroma quality, amount and aftertaste. [Conclusion] The four-shelf bulk curing barn had a large volume for tobacco leaf processing, but a similar baking environment to the commonness barn, which is conducive to the formation and accumulation of aroma components, so the finished leaves had similar appearance and quality with those flue-cured in commonness barn. The upper flue-cured leaves in three-shelf bulk curing bran had poorer quality than those flue-cured in the other two barns. 展开更多
关键词 Bulk curing barn Commonness barn Flue-cured tobacco K326 Upper leaf Aroma quality
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Cure Kinetics of DGEBA with Hyperbranched Poly(3-hydroxyphenyl) Phosphate as Curing Agent Studied by Non-isothermal DSC 被引量:6
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作者 YAO Liang DENG Jing QU Bao-jun SHI Wen-fang 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第1期118-122,共5页
The cure kinetics of diglycidyl ether of bisphenol A (DGEBA) with hyperbranched poly (3-hydroxyphenyl) phosphate(HHPP) as the curing agent was investigated by means of non-isothermal differential scanning calori... The cure kinetics of diglycidyl ether of bisphenol A (DGEBA) with hyperbranched poly (3-hydroxyphenyl) phosphate(HHPP) as the curing agent was investigated by means of non-isothermal differential scanning calorimetry (DSC) at various heating rates. The results were compared with the corresponding results by using 1,3-dihydroxybenzene(DHB) as a model compound. The results show that HHPP can enhance the cure reaction of DGEBA, resulting in the decrease of the peak temperature of the curing curve as well as the decrease of the activation energy because of the flexible --P--O-- groups in the backbone of HHPP. However, both the activation energy of the cured polymer and the peak temperature of the curing curve are increased with DHB as a curing agent. The cure kinetics of the DGEBA/HHPP system was calculated by using the isoconversional method given by Malek. It was found that the two-parameter autocatalytic model(Sestak-Berggren equation) is the most adequate one to describe the cure kinetics of the studied System at various heating rates. The obtained non-isothermal DSC curves from the experimental data show the results being accordant with those theoretically calculated. 展开更多
关键词 Hyperbranched polyphosphate Cure kinetics Epoxy resin Non-isothermal DSC
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The Mechanism of Carotenoid Degradation in Flue-Cured Tobacco and Changes in the Related Enzyme Activities at the Leaf-Drying Stage During the Bulk Curing Process 被引量:6
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作者 SONG Zhao-peng LI Tong-shuai +3 位作者 ZHANG Yong-gang CAO Hui-jing GONG Chang-rong ZHANG Wei-jian 《Agricultural Sciences in China》 CSCD 2010年第9期1381-1388,共8页
The mechanism of carotenoid degradation and the changes in the activities of related enzymes in flue-cured tobacco at the leaf-drying stage during the bulk-curing process were studied in order to provide theoretical b... The mechanism of carotenoid degradation and the changes in the activities of related enzymes in flue-cured tobacco at the leaf-drying stage during the bulk-curing process were studied in order to provide theoretical basis for optimization of curing technology. The effect of different rising speeds of temperature on the carotenoid degradation and the related enzymes activities at the color-fixing stage during the bulk curing process was studied by using the electric-heated fluecuring barn designed by Henan Agricultural University, China, based on curing technology with yellowing at low temperature and moderate humidity and leaf drying at moderate humidity. The results showed that the carotenoid degradation components (β-carotene, lutein, neoxanthin, and violaxthin) decreased gradually at the color-fixing stage during the bulk curing process. The carotenoid degradation components viz.,β-carotene, lutein, neoxanthin, and violaxthin at the slow heating curing (T1) were relatively higher than the rapid heating curing (T2) accounting for 10, 2, 32 and 32% respectively, but there were no differences among treatments (P〉 0.05). The effect of different conditions of curing on the activities of enzymes related to carotenoids degradation were significant. The lipoxygenase, phenylalanine ammonialyase, peroxidase, and polyphenol oxidase enzymes had a bidirectional effect on the quality of tobacco leaves and it was beneficial to form more premise matter of aroma based on the higher enzyme activities at the early leaf-drying stage. The slow heating could regulate the change in various enzymes' activities reasonably, making cell redox reaction to reach the dynamic balance and make the degradation of carotenoids adequately. Meanwhile, it could avoid the occurrence of browning reaction and provide foundation for improving the quality of tobacco and optimization of technology for bulk curing and further enhancing aroma. 展开更多
关键词 bulk curing leaf-drying stage carotenoids mechanism of degradation enzyme
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Influence of subsequent curing on water sorptivity and pore structure of steam-cured concrete 被引量:5
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作者 贺智敏 龙广成 谢友均 《Journal of Central South University》 SCIE EI CAS 2012年第4期1155-1162,共8页
Steam-cured condition is found to cause larger porosity and worse properties of concrete compared with normal curing condition. For the sake of seeking effective measurements to eliminate this bad effect of steam-cure... Steam-cured condition is found to cause larger porosity and worse properties of concrete compared with normal curing condition. For the sake of seeking effective measurements to eliminate this bad effect of steam-cured condition on concrete, the water sorptivity and pore structure of steam-cured concretes exposed to different subsequent curing conditions were investigated after steam-curing treatment. The capillary absorption coefficient and porosity of the corresponding concretes were analyzed, and their mechanisms were also discussed. The results indicate that water sorptivity and pore structure of steam-cured concrete are greatly influenced by the curing condition used in subsequent ages. Exposure steam-cured concrete to air condition has an obviously bad effect on its properties and microstructures. Adopting subsequent curing of immersing steam-cured concrete into about 20℃ water after steam curing period can significantly decrease its capillary absorption coefficient and porosity. Steam-cured concrete with 7 d water curing has minimum capillary absorption coefficient and total porosity. Its water sorptivity is decreased by 23% compared with standard curing concrete and the porosity is 9.6% lower. Moreover, the corresponding gradient of water sorptivity and porosity of steam-cured concrete both decrease, thus mictostructure of concrete becomes more homogeneous. 展开更多
关键词 steam-cured concrete water sorptivity pore structure curing condition
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Application of Polyurethane Curing Barn in Flue-cured Tobacco Production 被引量:1
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作者 Ang LI Qingzhi JANG +2 位作者 Wenjian ZHANG Zhong WANG Jun WAN 《Agricultural Biotechnology》 CAS 2016年第2期34-36,39,共4页
[ Objective] This study aimed to investigate the curing performance of polyurethane curing barn and reduce the cost of tobacco leaf flue-curing. [ Meth- odl The temperature control effect, curing effect and curing cos... [ Objective] This study aimed to investigate the curing performance of polyurethane curing barn and reduce the cost of tobacco leaf flue-curing. [ Meth- odl The temperature control effect, curing effect and curing cost of polyurethane curing barn and traditional bulk curing barn were analyzed and compared. [ Re- suit] The results showed that there were no significant differences in curing performance between two types of curing barns. Horizontal temperature differences in- creased slightly as the temperature rose. Specifically, horizontal temperature differences between each layer ranged from 0.2 ~C to 0.5 ~. Both two types of curing barns exhibited uniform air distribution. Polyurethane curing barn exhibited stable vertical temperature differences. Both two types of curing barns presented good curing effects with slight differences. Polyurethane curing barn exhibited higher economic benefits, lower coal cost, lower electricity cost, lower labor cost and lon- ger service life than traditional bulk curing barn, but its construction cost was higher. [ Conclusion] Polyurethane curing barn exhibits better curing performance with ~ood application prospects. 展开更多
关键词 Polyurethane curing barn curing effect curing cost
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Influence of Reactive Diluent on UV-curing of AcrylateTerminated Hyperbranched Polymers 被引量:2
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作者 TANGLi-ming FANGYu YANLiang FUZhi-wei 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第2期248-252,共5页
A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis(methylol) propionic acid and tris(methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers a... A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis(methylol) propionic acid and tris(methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers alone or with a monofunctional diluent, isobornylene acrylate(IBOA) were further cured by UV radiation. The cured films based on the modified polymers alone all demonstrated poor mechanical properties due to their high network densities and low moving ability of polymer chains. For the composite systems, the cured films demonstrated improved mechanical properties due to the low network densities and high chain moving ability. With more IBOA included in the systems, acrylate groups can react to a higher extent during the curing process. 展开更多
关键词 Reactive diluent UV curing Acrylated hyperbranched polymer
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Curing Mechanism of Condensed Polynuclear Aromatic Resin and Thermal Stability of Cured Resin 被引量:1
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作者 Li Shibin Sun Qiqian +2 位作者 Wang Yuwei Wu Mingbo Zhang Zailong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第2期9-16,共8页
In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by p... In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by proton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier transform infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermogravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the curing process, and the curing mechanism was confirmed to be the electrophilic substitution reaction. Compared with the uncured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65% at 600 ℃, which was much higher than 25.02% of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability. 展开更多
关键词 condensed polynuclear aromatic resin SYNTHESIS vacuum residue curing thermal stability
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CURING KINETICS AND PROPERTIES OF ACRYLIC RESIN CURED WITH AZIRIDINE CROSSLINKER
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作者 魏德卿 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2002年第1期65-70,共6页
A kind of aziridine crosslinkers was synthesized and used to crosslink acrylate copolymers. The crosslinking properties and curing kinetics of the resin were studied. It was found that with the increase of the content... A kind of aziridine crosslinkers was synthesized and used to crosslink acrylate copolymers. The crosslinking properties and curing kinetics of the resin were studied. It was found that with the increase of the content of crosslinker in the emulsion, the mechanical properties and solvent resistance of the resin will be apparently improved, but its glass transition temperature (T.) is very low. The lowest amount of crosslinker used in the acrylic resin emulsion is 0.25%. Curing kinetics studied by DSC show that this curing reaction occurs readily because the apparent activation energy of the reaction is low (65.1 kJ/mol). These results demonstrate that the aziridine crosslinker is indeed a low temperature crosslinking agent and can be used at room temperature. 展开更多
关键词 AZIRIDINE acrylic resin CROSSLINK curing kinetics differential scanning calorimetry (DSC)
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Effects of Different Flue-curing Technologies on Microscopic Structure of Flue-cured Tobacco Leaves 被引量:1
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作者 Guomin CUI Bojun WANG +4 位作者 Rongchun LI Anding XU Yiyin CHEN Chao YANG Min PU 《Agricultural Biotechnology》 CAS 2014年第2期28-34,共7页
[Objective] This study aimed to compare the effects of Chinese quality-improving fragrunce-increasing tobacco flue-curing technology, Chinese three- stage tobaeeo flue-curing technology and Zimbabwean tobaceo flue-eur... [Objective] This study aimed to compare the effects of Chinese quality-improving fragrunce-increasing tobacco flue-curing technology, Chinese three- stage tobaeeo flue-curing technology and Zimbabwean tobaceo flue-euring technology on microscopie structure of flue-cured tobacco leaves to provide theoretical basis for tobacco flue-curing. [ Method ] Middle leaves of tobacco cultivar K326 were collected in Pengshui County of Chongqing City for flue-curing experiment using three flue-curing technologies. Leaf samples were collected regularly in the flue-curing process, to investigate the microscopic structure of flue-cured tobaceo leaves. [ Result] During three flue-curing processes, leaves, palisade tissues and sponge tissues shrank gradually. Three flue-euring processes exhibited significant differ- ences in the peak of tissue shrinkage : microscopic structure of flue-cured tobacco leaves in Chinese three-stage tobacco flue-curing process shrank earliest, follower by Chinese quality-improving fragrance-increasing tobacco flue-curing process; flue-eured tobacco leaves in Zimbabwean tobacco flue-curing process presented the latest shrinkage. At 84 h post-curing, leaf thickness in three flue-curing processes showed a descend order of Chinese three-stage tobacco flue-curing process 〉 Chinese quality-improving fragrance-increasing tobacco flue-curing process 〉 Zimbabwean tobacco flue-curing process. Upper and lower epidermal cells in Zimb- abwean tobacco flue-curing process ruptured earlier than other two flue-curing processes; eventually, the majority of cells ruptured and mixed with palisade tissues and sponge tissues. In Chinese quality-improving fragranee-increasing tobacco flue-curing process, only a small number of epidermal cells in dried leaves ruptured. Among three flue-curing technologies, Zimbabwean tobacco flue-curing technology exhibited the greatest damage to epidermal cells, followed by Chinese three-stage tobaceo flue-curing technology; Chinese quality-improving fragrance-increasing tobacco flue-curing technology had the minimum damage to epidermal cells. Mese- phyll cross-section exhibited significant morphological changes in stomata. To be specific, at 0 - 12 h post-curing, stomata of tobacco leaves closed with slightly prominent stamatal apparatuses on upper and lower epidermis; at 24 -72 h post-curing, stomata of tobaceo leaves changed gradually from opening to closure with significantly prominent stomatal apparatuses on upper and lower epidermis; at 84 h post-curing, stomata of tobacco leaves closed, and the majority of stomatal appa- ratuses were significantly prominent. In Chinese quality-improving fragrance-increasing tobacco flue-curing process, only a small number of epidermal ceils ruptured at 84 h pest-flue-curing; palisade tissues and sponge tissues shrank almost simultaneously. Significant gaps were observed between palisade tissues and between pal- isade tissues and sponge tissues. Chinese quality-improving fragrance-increasing tobacco flue-curing technology exhibited lower disorder level compared with other two flue-curing technologies. [ Conclusion] Chinese quality-improving fragrance-increasing tobacco flue-curlng technology was conducive to maintaining the micro- scopic structure integrity of flue-cured tobacco leaves and obtaining high-quality flue-cured tobacco leaves. 展开更多
关键词 Flue-cured tobacco leaves Flue-curing technologies Microscopic structure
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Effects of Different Flue-curing Technologies on Submicroscopic Structure of Flue-cured Tobacco Leaves 被引量:1
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作者 Guomin CUI Bojun WANG +4 位作者 Rongchun LI Anding XU Yiyin CHEN Chao YANG Min PU 《Agricultural Biotechnology》 CAS 2014年第1期43-49,共7页
[ Objective] This study aimed to compare the effects of low-temperature low-humidity tobacco flue-curing technology, moderate-temperature moderate- humidity tobacco flue-curing technology and moderate-temperature high... [ Objective] This study aimed to compare the effects of low-temperature low-humidity tobacco flue-curing technology, moderate-temperature moderate- humidity tobacco flue-curing technology and moderate-temperature high-humidity tobacco flue-curing technology on submicroscopic structure of flue-cured tobacco leaves to provide theoretical basis for tobacco flue-curing. [ Method] Middle leaves of tobacco cuhivar K326 were collected in Pengshui County of Chongqing City for flue-curing experiment using three flue-curing technologies. Leaf samples were collected regularly in the flue-curing process, to investigate the submicroscopic structure of flue-cured tobacco leaves. [ Result] Morphology changes and structural rupture of chloroplasts occurred at different time during three flue-curing proces- ses. In low-temperature low-humidity flue-curing process, morphology changes and structural rupture of chloroplasts occurred late but rapidly; in moderate-tempera- ture moderate-humidity flue-curing process and moderate-temperature high-humidity flue-curing process, morphology changes and structural rupture of chloroplasts occurred early but slowly. Among these three flue-curing processes, the speed of changes in mitochondria morphology, cristae number and membrane rupture pres- ented an upward order of low-temperature low-humidity flue-curing process 〈 moderate-temperature high-humidity flue-curlng process 〈 moderate-temperature moderate-humidity flue-curing process. In low-temperature low-humldity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 36 -48 h ; in moderate-temperature moderate-humidity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 24 - 36 h; in moderate-temperature high-humidity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 12 - 24 h. [ Conclusion ] Using low-temperature low-humidity flue- curing technology could prolong the maintenance duration of the submicroscopic structure integrity of flue-cured tobacco leaves, which was conducive to fully decom- posing and transforming substances in tobacco leaves and obtaining high-quality flue-cured tobacco leaves. 展开更多
关键词 Flue-cured tobacco leaves Flue-curing technologies Submicroscopic structure
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UV-阳离子杂化体系及其在喷墨阻焊中的应用研究 被引量:1
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作者 刘媛 姚露 +2 位作者 刘晓暄 韩栋 廖正福 《中国胶粘剂》 CAS 2024年第3期50-55,61,共7页
喷墨打印是一种较为新颖的无接触式印刷技术,高效、经济、环保的特点使其在阻焊制程中有广泛的发展前景。本研究通过对比紫外光固化涂层的固化速度、附着力和硬度等性能,从市售的5种阳离子单体中,优选出脂环族环氧单体3,4-环氧环己基甲... 喷墨打印是一种较为新颖的无接触式印刷技术,高效、经济、环保的特点使其在阻焊制程中有广泛的发展前景。本研究通过对比紫外光固化涂层的固化速度、附着力和硬度等性能,从市售的5种阳离子单体中,优选出脂环族环氧单体3,4-环氧环己基甲酸-3’,4’-环氧环己基甲酯(TTA-21)作为杂化体系的阳离子单体。选择质量比为2∶3的TTA-21/1,6-己二醇二丙烯酸酯(HDDA)混杂体系配方为研究对象,对其反应转化率、固化程度、热性能、热稳定性以及所制备油墨在阻焊中的应用进行研究。研究结果表明:(1)在LED光照下,自由基组分和阳离子组分均会发生聚合反应,自由基体系的反应速度快,且反应转化率更高;阳离子反应速度慢,且转化率相对低,短时间内持续的光照并不能显著提升阳离子的反应转化率;在光-热双重固化下,阳离子环氧开环聚合与自由基双键加成反应的反应程度增加,固化进行得更彻底。(2)杂化体系的固化产物存在两相,但是热重曲线显示只有一个失重曲线,说明杂化体系经过LED加热烘烤后,体系中可能形成了互穿交联网络结构;环氧组分和丙烯酸组分存在一定的微相分离结构,这种微相分离结构提升了固化膜的综合性能。(3)应用研究表明,制备的合格阻焊墨水黏度为8~14 mPa·s(45℃),表面张力在22 mN/m左右,粒径在135~150 nm范围,耐溶剂、耐酸碱和耐焊锡性能均可以满足阻焊墨水的要求。 展开更多
关键词 紫外光固化 阳离子 杂化体系 喷墨打印 阻焊墨水
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玻纤增强甲基丙烯酸酯基UV-CIPP材料抗弯性能及失效分析
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作者 夏洋洋 方宏远 +2 位作者 张超 王翠霞 石明生 《材料导报》 EI CAS CSCD 北大核心 2024年第12期290-296,共7页
管道修复用紫外光原位固化(Ultraviolet cured-in-place pipe,UV-CIPP)材料是一种玻纤复合材料,其抗弯性能是评价管道修复效果以及材料优化设计所需的重要参考指标。以玻纤增强甲基丙烯酸酯基UV-CIPP材料为研究对象,考虑固化时间、固化... 管道修复用紫外光原位固化(Ultraviolet cured-in-place pipe,UV-CIPP)材料是一种玻纤复合材料,其抗弯性能是评价管道修复效果以及材料优化设计所需的重要参考指标。以玻纤增强甲基丙烯酸酯基UV-CIPP材料为研究对象,考虑固化时间、固化距离、紫外灯功率和材料厚度的影响,基于融合高清视频和SEM观测的三点弯曲试验,对玻纤增强甲基丙烯酸酯基UV-CIPP材料抗弯性能和失效机制进行了研究。结果表明,UV-CIPP材料的失效过程可以分为三个阶段:弹性阶段、基体开裂阶段和玻纤布断裂阶段,基体开裂、脱粘分层和纤维拉拔断裂是玻纤增强甲基丙烯酸酯基UV-CIPP材料弯曲失效的主要原因。在单一变量影响下,玻纤增强甲基丙烯酸酯基UV-CIPP材料弯曲强度和弯曲模量随固化时间、固化距离和紫外灯功率的增大均呈现出先增大后减小的趋势,随着材料厚度的增大却逐渐减小。本研究不仅为UV-CIPP材料的优化设计提供了参考依据,也为国产化UV-CIPP材料的发展奠定了重要基础。 展开更多
关键词 紫外光原位固化(uv-CIPP)材料 三点弯曲试验 高清视频 SEM 固化参数 材料厚度
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Nitrogen Metabolism and Curing Characteristics of Flue-cured Tobacco Variety NC71
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作者 Cong ZHENG Wei LI +3 位作者 Bo LI Hongquan SUN Zhigang LU Yongfeng AI 《Asian Agricultural Research》 2021年第10期63-70,75,共9页
[Objectives]To explore the growth characteristics,nitrogen metabolism and curing characteristics of the new variety NC71 in strongly aromatic tobacco leaves production area.[Methods]With Yunyan 87 as the control and N... [Objectives]To explore the growth characteristics,nitrogen metabolism and curing characteristics of the new variety NC71 in strongly aromatic tobacco leaves production area.[Methods]With Yunyan 87 as the control and NC71 as the experimental material,the experiment was carried out in Nanyang tobacco area for two consecutive years to study the growth characteristics of tobacco plants,the activity of key enzymes in nitrogen metabolism,the content of secondary metabolites,and the differences of tobacco-related water content,PPO enzyme activity and total phenol content.[Results]NC71 plants had lower height,better appearance quality and lower nicotine,total sugar and chlorine content.NC71 high nitrogen treatment and Yunyan 87 medium nitrogen treatment had similar key enzyme activity of nitrogen metabolism,content of secondary metabolites;Yunyan 87 and NC71 were easy to cure and resistant to curing.[Conclusions]This study provides a reference for measuring the appropriate nitrogen application rate and optimizing the curing process from the activities of the key enzymes NR and GS in nitrogen metabolism at the mature stage of the variety. 展开更多
关键词 VARIETY Nitrogen metabolism curing characteristics
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Fabrication and Properties of a New Reactive Diluent for Cationic UV Curing
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作者 吴正森 黄笔武 +1 位作者 LIU Yuansheng SHEN Han 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第4期1053-1060,共8页
The reactive diluent prepared by siloxane modified Trimethylene oxide can improve the performance of the UV curing system.Therefore,1,7-bis[(3-ethyl-3-methoxyoxacylobutane)propyl]octadecylosiloxane(BEMOPOMTS)was synth... The reactive diluent prepared by siloxane modified Trimethylene oxide can improve the performance of the UV curing system.Therefore,1,7-bis[(3-ethyl-3-methoxyoxacylobutane)propyl]octadecylosiloxane(BEMOPOMTS)was synthesized from diethyl carbonate,trimethylopropanes,allyl bromide,and 1,1,3,3,5,5,7,7-octadecylosiloxane as the main raw materials.BEMOPOMTS can be used as reactive diluents in the field of cationic UV curing.It has good thermal stability,and the addition of BEMOPOMTS significantly improves the tensile strength and elongation at break of epoxy resin.Compared with the pure epoxy resin,adding 20%BEMOPOMTS increased the elastic modulus by 25%to 677 MPa. 展开更多
关键词 UV curing cation curing reactive diluent SILOXANE
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Experimental investigation of vibration pretreatment-microwave curing process for carbon fiber reinforced resin matrix composites
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作者 ZHANG De-chao ZHAN Li-hua +4 位作者 MA Bo-lin YAO Shun-ming GUO Jin-zhan GUAN Cheng-long LIU Shu 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期1838-1855,共18页
The vibration pretreatment-microwave curing process is an efficient,low energy consumption,and high-quality out-of-autoclave curing process for carbon fiber resin matrix composites.This study aims to investigate the i... The vibration pretreatment-microwave curing process is an efficient,low energy consumption,and high-quality out-of-autoclave curing process for carbon fiber resin matrix composites.This study aims to investigate the impact of vibration pretreatment temperature on the fiber weight content,microscopic morphology and mechanical properties of the composite laminates by using optical digital microscopy,universal tensile testing machine and thermo-gravimetric analyzer.Additionally,the combined mode of Bragg fiber grating sensor and temperature measurement fiber was employed to explore the effect of vibration pretreatment on the strain process during microwave curing.The study results revealed that the change in vibration pretreatment temperature had a slight impact on the fiber weight content when the vibration acceleration remained constant.The metallographic and interlaminar strength of the specimen formed at a vibration pretreatment temperature of 80℃ demonstrated a porosity of 0.414% and a 10.69% decrease in interlaminar shear strength compared to autoclave curing.Moreover,the introduction of the vibration energy field during the microwave curing process led to a significant reduction in residual strain in both the 0°and 90°fiber directions,when the laminate was cooled to 60℃. 展开更多
关键词 VIBRATION microwave curing POROSITY interlaminar shear strength thermo-gravimetric analysis curing strain
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基于改进CURE聚类的运营商用户云数据挖掘方法 被引量:1
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作者 雷中锋 徐秀 +3 位作者 张艳菲 曲延庆 宋强 刘良 《电脑编程技巧与维护》 2024年第4期62-64,共3页
为了优化运营商用户云数据挖掘效果、提升数据挖掘质量,开展基于改进CURE聚类的运营商用户云数据挖掘方法研究。首先,确定运营商用户云数据来源,采集与预处理运营商用户云数据。其次,设计数据挖掘关联规则,得出不同用户云数据之间的关... 为了优化运营商用户云数据挖掘效果、提升数据挖掘质量,开展基于改进CURE聚类的运营商用户云数据挖掘方法研究。首先,确定运营商用户云数据来源,采集与预处理运营商用户云数据。其次,设计数据挖掘关联规则,得出不同用户云数据之间的关联性。最后,利用改进CURE聚类算法,设计运营商用户云数据挖掘流程,输出聚类结果作为数据挖掘结果,并建立数据仓库,集中存储和管理用户云数据挖掘结果。实验结果表明,运用提出的方法,数据挖掘轮廓系数更接近1,聚类合理,挖掘效果优势显著,应用效果较好。 展开更多
关键词 改进CURE聚类 运营商 用户 云数据 挖掘
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