[Objective] The purpose of this study was to determine the effect of chitosan with different molecular weights on quality and lignification of postharvest Chi- nese chive scapes （Allium tuberosum Rottler ex Sprengel...[Objective] The purpose of this study was to determine the effect of chitosan with different molecular weights on quality and lignification of postharvest Chi- nese chive scapes （Allium tuberosum Rottler ex Sprengel）. [Method] Some physio- logical and biochemical indexes such as weight loss, decay index, opening rate of flowers, chlorophyll and ascorbic acid content, respiration rate, the activities of enzymes, lignin and cellulose content of Chinese chive scapes treated with three kinds of chitosan with different molecular weights were investigated during the room stor- age at 20 ℃ to simulate shelf life. [Result] The results showed that all the treat- ments of chitosan with different molecular weights significantly delayed weight loss, decay index and opening rate of flowers, maintained higher chlorophyll and ascorbic acid content, inhibited respiration rate, reduced the activities of enzymes phenylala- nine ammonia lyase, cinnamyl alcohol dehydrogenase and peroxidase, and retarded lignin and cellulose accumulation during the storage of Chinese chive scapes. However, high molecular weight chitosan has better preservation effect on Chinese chive scapes. [Conclusion] The results suggest that the coating treatment of high molecu- lar weight chitosan may be a promising technique to maintain postharvest quality of Chinese chive scapes.展开更多
During long term storage at 25℃ in the dark,a large number of cell content were transferred from the senescing scape to the developing cloves,and the transfer from the basal part of scape was earlier than that from t...During long term storage at 25℃ in the dark,a large number of cell content were transferred from the senescing scape to the developing cloves,and the transfer from the basal part of scape was earlier than that from the apical part in the excised garlic scape ( Allium sativum var Taichang).Levels of H 2O 2 decreased in the cloves and significantly increased up to 10 folds and then declined quickly in the scape.Levels of H 2O 2 were enhanced early in the basal part of scape.In the treatment of GA 3 at the cloves,levels of H 2O 2 were strongly enhanced in the cloves and inhibited in the scape,coinciding with the distinct inhibition of cell content tansfer.The results indicated that H 2O 2 may be involved in cell content redistribution and its regulation.3-Amino-1,2,4-triazole (AT) is a specific inhibitor of catalase.Effects of AT on cell content redistribution and levels of H 2O 2 were almost similar to those of GA 3,It further proved the above concept.According to the changes of H 2O 2 leves and activities of peroxidase and catalase in the cloves and in the scape,we suggest that the accumulation of H 2O 2 in the scape was transducted from the cloves,and the decline of H 2O 2 level in the scape with GA 3 or AT at the cloves was mainly through the inhibition of H 2O 2 synthesis in the cloves.展开更多
Research papers encompassing forest sciences,forest pest and disease control,forest resources information management,soil and water conservation,land-scape architecture and plants,forest machinery,timber processing,fo...Research papers encompassing forest sciences,forest pest and disease control,forest resources information management,soil and water conservation,land-scape architecture and plants,forest machinery,timber processing,forest chem-icals and forest economics and management,besides those with experimentaland interdisciplinary approaches,are accepted for the publication in Journal ofBeijing Forestry University(English Edition).The maximum length of the pa-per is usually restricted to 12 pages.Short communications presenting interesting findings in one or two pages展开更多
Eco-city development is a healthy process towards sustainable development, within the carrying capacity of local ecosystem through changing production mode, consumption behavior and decision instrument based on ecolog...Eco-city development is a healthy process towards sustainable development, within the carrying capacity of local ecosystem through changing production mode, consumption behavior and decision instrument based on ecological economics and system engineering. The key to its planning is an ecological integration to make trade-off between economic wealth and environmental health, between material and spiritual civilization, between natural and human eco-cybernetics. Integration, demonstration, citizens’ participation and scientists’ and technician’s catalyzing are the key instruments for the implementation of the ecocity plan. "Clean production" and "ecological industry" are key elements in comprehensive development towards an eco-city. Beyond the technical and management questions, how to interlink production, consumption and reduction at the local and regional level, the spatial and urban dimension should be considered in order to perform an integrative urban eco-space.展开更多
PEKING appliqu(?),one of the many handicrafts of China,is an old art-form going backmany centuries.Different materialsare cut out and attached to oneanother to create a single-piece de-coration,much like embroidery.It...PEKING appliqu(?),one of the many handicrafts of China,is an old art-form going backmany centuries.Different materialsare cut out and attached to oneanother to create a single-piece de-coration,much like embroidery.Itshistory can be traced back 2,000years to the Han Dynasty,whenartists would use thin scraps andpatches of silk to piece together aportrait or a depiction of the land-scape.During the Song Dynastyappliqu(?) enjoyed a resurgence andbecame very similar to traditionalembroidery.After the Qing Dynas-ty,appliqu(?) became very popularoutside the emperor＇s court and res-pectable women everywhere tookit up as a pastime。展开更多
A group of artists consisthingmainly of members of theJilin Academy of Art is ac-tive in the vast snowy area ofnortheast China.These artits go tothe mountain and fields to learn.about ordinaly people’s lives andcusto...A group of artists consisthingmainly of members of theJilin Academy of Art is ac-tive in the vast snowy area ofnortheast China.These artits go tothe mountain and fields to learn.about ordinaly people’s lives andcustoms and depict these and thelandscapes in their paintings。Nourished by the white moun-a bold,simple and vivid style.Huang Qiushi,a famous land-scape painter of the northern school,uses vigorous strokes with a free andnatural application of ink.His paint-ings are in grand style,revealingvigor and vitality and depicting theexternal world vividly and truly, butat the same time expressing his ownideas and feelings.He thinks his展开更多
It is of great significance to study the water absorption and expansion of cells,which are essential for the growth and life regulation of plants,not only for understanding the complex life phenomena of plants,but als...It is of great significance to study the water absorption and expansion of cells,which are essential for the growth and life regulation of plants,not only for understanding the complex life phenomena of plants,but also for the manufacture of biomimetic materials.The main purpose of this study is to shed light on the mechanism of a novel coiling phenomenon of the split dandelion scape soaked in water and the high concentration mannitol solution.We discovered that the difference between water absorption/dehydration capacities of inner cells and lateral cells of the split dandelion scape generates asymmetric expansion/contraction between inner and lateral layers,resulting two opposite coiled patterns.Analogous to the deformable hypothesis of the thermal expansion model,the water absorption-induced cell expansion model was proposed to explain the coiling process of the split dandelion scape.Both the simulation and experimental results revealed that the coiling of dandelion scape is strongly depended on the response of cells to the stimulation of the solution environment.Showing considerable potential load bearing capacity of plants,the coiling phenomenon can be an inspiration to the designs of soft robots and bionic sensors for humidity control.展开更多
In December 2019,an outbreak of pneumonia,which was named COVID-2019,emerged as a global health crisis.Scientists worldwide are engaged in attempts to elucidate the transmission and pathogenic mechanisms of the causat...In December 2019,an outbreak of pneumonia,which was named COVID-2019,emerged as a global health crisis.Scientists worldwide are engaged in attempts to elucidate the transmission and pathogenic mechanisms of the causative coronavirus.COVID-19 was declared a pandemic by the World Health Organization in March 2020,making it critical to track and review the state of research on COVID-19 to provide guidance for further investigations.Here,bibliometric and knowledge mapping analyses of studies on COVID-19 were performed,including more than 1,500 papers on COVID-19 available in the PubMed and China National Knowledge Infrastructure databases from January 1,2020 to March 8,2020.In this review,we found that because of the rapid response of researchers worldwide,the number of COVID-19-related publications showed a high growth trend in the first 10 days of February;among these,the largest number of studies originated in China,the country most affected by pandemic in its early stages.Our findings revealed that the epidemic situation and data accessibility of different research teams have caused obvious difference in emphases of the publications.Besides,there was an unprecedented level of close cooperation and information sharing within the global scientific community relative to previous coronavirus research.We combed and drew the knowledge map of the SARS-CoV-2 literature,explored early status of research on etiology,pathology,epidemiology,treatment,prevention,and control,and discussed knowledge gaps that remain to be urgently addressed.Future perspectives on treatment,prevention,and control are also presented to provide fundamental references for current and future coronavirus research.展开更多
基金Supported by Jiangsu Agriculture Science and Technology Innovation Fund[CX(11)4056]Strategic Key Project of Jiangsu Provincial Science and Technology Development(BE 2012417)~~
文摘[Objective] The purpose of this study was to determine the effect of chitosan with different molecular weights on quality and lignification of postharvest Chi- nese chive scapes （Allium tuberosum Rottler ex Sprengel）. [Method] Some physio- logical and biochemical indexes such as weight loss, decay index, opening rate of flowers, chlorophyll and ascorbic acid content, respiration rate, the activities of enzymes, lignin and cellulose content of Chinese chive scapes treated with three kinds of chitosan with different molecular weights were investigated during the room stor- age at 20 ℃ to simulate shelf life. [Result] The results showed that all the treat- ments of chitosan with different molecular weights significantly delayed weight loss, decay index and opening rate of flowers, maintained higher chlorophyll and ascorbic acid content, inhibited respiration rate, reduced the activities of enzymes phenylala- nine ammonia lyase, cinnamyl alcohol dehydrogenase and peroxidase, and retarded lignin and cellulose accumulation during the storage of Chinese chive scapes. However, high molecular weight chitosan has better preservation effect on Chinese chive scapes. [Conclusion] The results suggest that the coating treatment of high molecu- lar weight chitosan may be a promising technique to maintain postharvest quality of Chinese chive scapes.
文摘During long term storage at 25℃ in the dark,a large number of cell content were transferred from the senescing scape to the developing cloves,and the transfer from the basal part of scape was earlier than that from the apical part in the excised garlic scape ( Allium sativum var Taichang).Levels of H 2O 2 decreased in the cloves and significantly increased up to 10 folds and then declined quickly in the scape.Levels of H 2O 2 were enhanced early in the basal part of scape.In the treatment of GA 3 at the cloves,levels of H 2O 2 were strongly enhanced in the cloves and inhibited in the scape,coinciding with the distinct inhibition of cell content tansfer.The results indicated that H 2O 2 may be involved in cell content redistribution and its regulation.3-Amino-1,2,4-triazole (AT) is a specific inhibitor of catalase.Effects of AT on cell content redistribution and levels of H 2O 2 were almost similar to those of GA 3,It further proved the above concept.According to the changes of H 2O 2 leves and activities of peroxidase and catalase in the cloves and in the scape,we suggest that the accumulation of H 2O 2 in the scape was transducted from the cloves,and the decline of H 2O 2 level in the scape with GA 3 or AT at the cloves was mainly through the inhibition of H 2O 2 synthesis in the cloves.
文摘Research papers encompassing forest sciences,forest pest and disease control,forest resources information management,soil and water conservation,land-scape architecture and plants,forest machinery,timber processing,forest chem-icals and forest economics and management,besides those with experimentaland interdisciplinary approaches,are accepted for the publication in Journal ofBeijing Forestry University(English Edition).The maximum length of the pa-per is usually restricted to 12 pages.Short communications presenting interesting findings in one or two pages
文摘Eco-city development is a healthy process towards sustainable development, within the carrying capacity of local ecosystem through changing production mode, consumption behavior and decision instrument based on ecological economics and system engineering. The key to its planning is an ecological integration to make trade-off between economic wealth and environmental health, between material and spiritual civilization, between natural and human eco-cybernetics. Integration, demonstration, citizens’ participation and scientists’ and technician’s catalyzing are the key instruments for the implementation of the ecocity plan. "Clean production" and "ecological industry" are key elements in comprehensive development towards an eco-city. Beyond the technical and management questions, how to interlink production, consumption and reduction at the local and regional level, the spatial and urban dimension should be considered in order to perform an integrative urban eco-space.
文摘PEKING appliqu(?),one of the many handicrafts of China,is an old art-form going backmany centuries.Different materialsare cut out and attached to oneanother to create a single-piece de-coration,much like embroidery.Itshistory can be traced back 2,000years to the Han Dynasty,whenartists would use thin scraps andpatches of silk to piece together aportrait or a depiction of the land-scape.During the Song Dynastyappliqu(?) enjoyed a resurgence andbecame very similar to traditionalembroidery.After the Qing Dynas-ty,appliqu(?) became very popularoutside the emperor＇s court and res-pectable women everywhere tookit up as a pastime。
文摘A group of artists consisthingmainly of members of theJilin Academy of Art is ac-tive in the vast snowy area ofnortheast China.These artits go tothe mountain and fields to learn.about ordinaly people’s lives andcustoms and depict these and thelandscapes in their paintings。Nourished by the white moun-a bold,simple and vivid style.Huang Qiushi,a famous land-scape painter of the northern school,uses vigorous strokes with a free andnatural application of ink.His paint-ings are in grand style,revealingvigor and vitality and depicting theexternal world vividly and truly, butat the same time expressing his ownideas and feelings.He thinks his
基金The authors greatly appreciate the financial support of the National Natural Science Foundation of China(11502155)Natural Science Foundation of Shanxi Province(201901D211112)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2019L0328).We thank Prof.Yuren Wang and Mrs.Tingt-ing Zhao for discussions.
文摘It is of great significance to study the water absorption and expansion of cells,which are essential for the growth and life regulation of plants,not only for understanding the complex life phenomena of plants,but also for the manufacture of biomimetic materials.The main purpose of this study is to shed light on the mechanism of a novel coiling phenomenon of the split dandelion scape soaked in water and the high concentration mannitol solution.We discovered that the difference between water absorption/dehydration capacities of inner cells and lateral cells of the split dandelion scape generates asymmetric expansion/contraction between inner and lateral layers,resulting two opposite coiled patterns.Analogous to the deformable hypothesis of the thermal expansion model,the water absorption-induced cell expansion model was proposed to explain the coiling process of the split dandelion scape.Both the simulation and experimental results revealed that the coiling of dandelion scape is strongly depended on the response of cells to the stimulation of the solution environment.Showing considerable potential load bearing capacity of plants,the coiling phenomenon can be an inspiration to the designs of soft robots and bionic sensors for humidity control.
文摘In December 2019,an outbreak of pneumonia,which was named COVID-2019,emerged as a global health crisis.Scientists worldwide are engaged in attempts to elucidate the transmission and pathogenic mechanisms of the causative coronavirus.COVID-19 was declared a pandemic by the World Health Organization in March 2020,making it critical to track and review the state of research on COVID-19 to provide guidance for further investigations.Here,bibliometric and knowledge mapping analyses of studies on COVID-19 were performed,including more than 1,500 papers on COVID-19 available in the PubMed and China National Knowledge Infrastructure databases from January 1,2020 to March 8,2020.In this review,we found that because of the rapid response of researchers worldwide,the number of COVID-19-related publications showed a high growth trend in the first 10 days of February;among these,the largest number of studies originated in China,the country most affected by pandemic in its early stages.Our findings revealed that the epidemic situation and data accessibility of different research teams have caused obvious difference in emphases of the publications.Besides,there was an unprecedented level of close cooperation and information sharing within the global scientific community relative to previous coronavirus research.We combed and drew the knowledge map of the SARS-CoV-2 literature,explored early status of research on etiology,pathology,epidemiology,treatment,prevention,and control,and discussed knowledge gaps that remain to be urgently addressed.Future perspectives on treatment,prevention,and control are also presented to provide fundamental references for current and future coronavirus research.
