The global existence of the heat flow for harmonic maps from noncompact manifolds is considered. When L^m norm of the gradient of initial data is small, the existence of a global solution is proved.
A weak solution to the heat flow problems is constructed.Nonuniqueness results of such solutions are also shown when the first data is a weak solution to the Euler Lagrange equation but not a weakly stationary soluti...A weak solution to the heat flow problems is constructed.Nonuniqueness results of such solutions are also shown when the first data is a weak solution to the Euler Lagrange equation but not a weakly stationary solution to it.展开更多
Peanut(Arachis hypogaea)is of international importance as a source of oil and protein.Soil salinity is one of themost significant abiotic stress factors affecting the yield and quality of peanuts.This study evaluated ...Peanut(Arachis hypogaea)is of international importance as a source of oil and protein.Soil salinity is one of themost significant abiotic stress factors affecting the yield and quality of peanuts.This study evaluated the potential of a seaweed-based biostimulant to enhance emergence and seedling growth of four peanut cultivars(‘Ayse Hanım’,‘Halis Bey’,‘NC-7’,and‘Albenek’)under increasing salinity levels.The experiment was conducted under greenhouse conditions using a randomized complete block design with four replicates.Seeds were sown in trays and treated with two doses of seaweed extract(0 and 5 g L^(-1))applied directly to the seedbed.Salinity stress was induced by dissolving NaCl in distilled water used for weekly irrigation over six weeks,with salinity levels set at:S_(0):Control,S_(1):50mMNaCl,S_(2):100 mM NaCl,S_(3):150 mM NaCl,and S_(4):200 mM NaCl.Emergence percentage,mean emergence time,shoot and root length,fresh and dry biomass,chlorophyll content,proline,crude protein,and macro-and micronutrient concentrations(Ca,K,P,Mg,Zn,Mn,Cu,and Fe)were measured.The results revealed significant differences between treatments.Seaweed applications showed notable improvements in measured parameters of each variety compared to the salt treated and un-treated control plants of each variety.As salinity stress increased,the emergence percentage,root and shoot length,fresh and dry weight of the plants,crude protein content percentage,leaf chlorophyll contents,Ca,K,P,Mg,Zn,Mn,Cu,and Fe decreased.Similarly,the mean emergence time,and proline contents also decreased with each increase in Na concentration.The best outcomes were obtained in seedlings treated with seaweed under no salinity(0 mM NaCl)and mild salinity(50 mM NaCl)conditions.These findings suggest that seaweeds is an effective biostimulant for improving early-stage growth and stress resilience in peanuts under saline conditions.展开更多
Several initiatives have been made in Egypt to increase the overall production of oil crops,especially sunflower and to close the gap between edible oil production and demand.Field experiments were conducted during th...Several initiatives have been made in Egypt to increase the overall production of oil crops,especially sunflower and to close the gap between edible oil production and demand.Field experiments were conducted during the main seasons of 2022 and 2023 at the agricultural research station of National Research Centre,Nubaria,Egypt to investigate the effects of potassium nitrate (0,20,40,60 kg K_(2)O fed^(-1))(fed=feddan=2.4 ha) and zinc sulfate(0,25,50,75 ppm Zn) on growth,oil yield,nutrients components and chemical composition of sunflower.Results indicated that application of potassium nitrate has a promoted effect on chlorophyll content,growth parameters(Head weight,head diameter and 100 seed weight),protein content,oil yield as well as nutrient content under all applied levels.The data also showed that the highest significant increase occurred with the soil application of 40kg fed^(-1)potassium nitrate combined with 75 ppm Zn foliar spray.Meanwhile,the lowest values were obtained at the control treatment.Therefore,the current study detected that potassium soil addition at 40 kg K_(2)O fed^(-1),besides foliar application with 75 ppm Zn are important to improve the growth,macro-micronutrient,seeds and oil productivity of sunflower crops.Oil yield and nutrient content exhibit a strong positive correlation,with a correlation coefficient of 0.903 for N,0.94 for P,0.962 for K and 0.966 for Zn.This indicates that a higher nutrient percentage is associated with higher oil content of sunflower.Study underscores the importance of comprehending the interplay between potassium and zinc treatments in sunflower plants to enhance growth,yield,and oil production effectively.Understanding these relationships can lead to optimized cultivation practices and improved outcomes in sunflower farming.展开更多
Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from...Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from the Global Biodiversity Information Facility(GBIF),population distribution data from the Oak Ridge National Laboratory(ORNL)in the United States,as well as information on the composition of tree species in suitable forest areas for birds and the forest geographical information of the Ming Tombs Forest Farm,which is based on literature research and field investigations.By using GIS technology,spatial processing was carried out on bird observation points and population distribution data to identify suitable bird-watching areas in different seasons.Then,according to the suitability value range,these areas were classified into different grades(from unsuitable to highly suitable).The research findings indicated that there was significant spatial heterogeneity in the bird-watching suitability of the Ming Tombs Forest Farm.The north side of the reservoir was generally a core area with high suitability in all seasons.The deep-aged broad-leaved mixed forests supported the overlapping co-existence of the ecological niches of various bird species,such as the Zosterops simplex and Urocissa erythrorhyncha.In contrast,the shallow forest-edge coniferous pure forests and mixed forests were more suitable for specialized species like Carduelis sinica.The southern urban area and the core area of the mausoleums had relatively low suitability due to ecological fragmentation or human interference.Based on these results,this paper proposed a three-level protection framework of“core area conservation—buffer zone management—isolation zone construction”and a spatio-temporal coordinated human-bird co-existence strategy.It was also suggested that the human-bird co-existence space could be optimized through measures such as constructing sound and light buffer interfaces,restoring ecological corridors,and integrating cultural heritage elements.This research provided an operational technical approach and decision-making support for the scientific planning of bird-watching sites and the coordination of ecological protection and tourism development.展开更多
目的基于超高效液相色谱-串联四级杆/线性离子阱质谱(ultra high performance liquid chromatography tandem fourth stage rod/linear ion trap mass spectrometry,UPLC-QTRAP-MS/MS)和多元统计分析,考察和评价不同干燥方式对乌药叶成...目的基于超高效液相色谱-串联四级杆/线性离子阱质谱(ultra high performance liquid chromatography tandem fourth stage rod/linear ion trap mass spectrometry,UPLC-QTRAP-MS/MS)和多元统计分析,考察和评价不同干燥方式对乌药叶成分的影响。方法采用UPLC-QTRAP-MS/MS技术,以ACQUITY UPLC?HSS T3(100 mm×2.1 mm,1.8μm)色谱柱分离,0.1%甲酸溶液(A相)-乙腈(B相)为流动相;梯度洗脱,柱温35℃,流量0.2 mL·min-1,多反应离子监测模式同时测定乌药叶10个成分,结合方差分析、聚类热图、熵权TOPSIS和灰色关联法对不同干燥方式后乌药叶多元化学成分进行综合评价。结果10个成分在一定的浓度范围内线性良好,相关系数均>0.9916;仪器精密度、方法重复性和供试品稳定性良好,RSD均<5%;加样回收率在99.13%~103.07%,RSD值均<5%。方差分析表明不同干燥方式后乌药叶6个成分差异具有统计学意义(P<0.05);聚类热图结果显示经不同干燥方式后各成分呈明显聚集趋势;TOPSIS与灰色关联法分析结果基本一致,最终经阴凉通风摊晾干燥处理后成分保留效果最佳。结论所建立的方法准确、可靠,可为乌药叶适宜的加工方式和品质规范化生产提供参考。展开更多
基金Supported by the National Natural Science Foundation of China (1057115610671079+1 种基金10701064)the Zijin Project of Zhejiang University
文摘The global existence of the heat flow for harmonic maps from noncompact manifolds is considered. When L^m norm of the gradient of initial data is small, the existence of a global solution is proved.
文摘A weak solution to the heat flow problems is constructed.Nonuniqueness results of such solutions are also shown when the first data is a weak solution to the Euler Lagrange equation but not a weakly stationary solution to it.
文摘Peanut(Arachis hypogaea)is of international importance as a source of oil and protein.Soil salinity is one of themost significant abiotic stress factors affecting the yield and quality of peanuts.This study evaluated the potential of a seaweed-based biostimulant to enhance emergence and seedling growth of four peanut cultivars(‘Ayse Hanım’,‘Halis Bey’,‘NC-7’,and‘Albenek’)under increasing salinity levels.The experiment was conducted under greenhouse conditions using a randomized complete block design with four replicates.Seeds were sown in trays and treated with two doses of seaweed extract(0 and 5 g L^(-1))applied directly to the seedbed.Salinity stress was induced by dissolving NaCl in distilled water used for weekly irrigation over six weeks,with salinity levels set at:S_(0):Control,S_(1):50mMNaCl,S_(2):100 mM NaCl,S_(3):150 mM NaCl,and S_(4):200 mM NaCl.Emergence percentage,mean emergence time,shoot and root length,fresh and dry biomass,chlorophyll content,proline,crude protein,and macro-and micronutrient concentrations(Ca,K,P,Mg,Zn,Mn,Cu,and Fe)were measured.The results revealed significant differences between treatments.Seaweed applications showed notable improvements in measured parameters of each variety compared to the salt treated and un-treated control plants of each variety.As salinity stress increased,the emergence percentage,root and shoot length,fresh and dry weight of the plants,crude protein content percentage,leaf chlorophyll contents,Ca,K,P,Mg,Zn,Mn,Cu,and Fe decreased.Similarly,the mean emergence time,and proline contents also decreased with each increase in Na concentration.The best outcomes were obtained in seedlings treated with seaweed under no salinity(0 mM NaCl)and mild salinity(50 mM NaCl)conditions.These findings suggest that seaweeds is an effective biostimulant for improving early-stage growth and stress resilience in peanuts under saline conditions.
文摘Several initiatives have been made in Egypt to increase the overall production of oil crops,especially sunflower and to close the gap between edible oil production and demand.Field experiments were conducted during the main seasons of 2022 and 2023 at the agricultural research station of National Research Centre,Nubaria,Egypt to investigate the effects of potassium nitrate (0,20,40,60 kg K_(2)O fed^(-1))(fed=feddan=2.4 ha) and zinc sulfate(0,25,50,75 ppm Zn) on growth,oil yield,nutrients components and chemical composition of sunflower.Results indicated that application of potassium nitrate has a promoted effect on chlorophyll content,growth parameters(Head weight,head diameter and 100 seed weight),protein content,oil yield as well as nutrient content under all applied levels.The data also showed that the highest significant increase occurred with the soil application of 40kg fed^(-1)potassium nitrate combined with 75 ppm Zn foliar spray.Meanwhile,the lowest values were obtained at the control treatment.Therefore,the current study detected that potassium soil addition at 40 kg K_(2)O fed^(-1),besides foliar application with 75 ppm Zn are important to improve the growth,macro-micronutrient,seeds and oil productivity of sunflower crops.Oil yield and nutrient content exhibit a strong positive correlation,with a correlation coefficient of 0.903 for N,0.94 for P,0.962 for K and 0.966 for Zn.This indicates that a higher nutrient percentage is associated with higher oil content of sunflower.Study underscores the importance of comprehending the interplay between potassium and zinc treatments in sunflower plants to enhance growth,yield,and oil production effectively.Understanding these relationships can lead to optimized cultivation practices and improved outcomes in sunflower farming.
基金Sponsored by Beijing Youth Innovation Talent Support Program for Urban Greening and Landscaping——The 2024 Special Project for Promoting High-Quality Development of Beijing’s Landscaping through Scientific and Technological Innovation(KJCXQT202410).
文摘Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from the Global Biodiversity Information Facility(GBIF),population distribution data from the Oak Ridge National Laboratory(ORNL)in the United States,as well as information on the composition of tree species in suitable forest areas for birds and the forest geographical information of the Ming Tombs Forest Farm,which is based on literature research and field investigations.By using GIS technology,spatial processing was carried out on bird observation points and population distribution data to identify suitable bird-watching areas in different seasons.Then,according to the suitability value range,these areas were classified into different grades(from unsuitable to highly suitable).The research findings indicated that there was significant spatial heterogeneity in the bird-watching suitability of the Ming Tombs Forest Farm.The north side of the reservoir was generally a core area with high suitability in all seasons.The deep-aged broad-leaved mixed forests supported the overlapping co-existence of the ecological niches of various bird species,such as the Zosterops simplex and Urocissa erythrorhyncha.In contrast,the shallow forest-edge coniferous pure forests and mixed forests were more suitable for specialized species like Carduelis sinica.The southern urban area and the core area of the mausoleums had relatively low suitability due to ecological fragmentation or human interference.Based on these results,this paper proposed a three-level protection framework of“core area conservation—buffer zone management—isolation zone construction”and a spatio-temporal coordinated human-bird co-existence strategy.It was also suggested that the human-bird co-existence space could be optimized through measures such as constructing sound and light buffer interfaces,restoring ecological corridors,and integrating cultural heritage elements.This research provided an operational technical approach and decision-making support for the scientific planning of bird-watching sites and the coordination of ecological protection and tourism development.
文摘目的基于超高效液相色谱-串联四级杆/线性离子阱质谱(ultra high performance liquid chromatography tandem fourth stage rod/linear ion trap mass spectrometry,UPLC-QTRAP-MS/MS)和多元统计分析,考察和评价不同干燥方式对乌药叶成分的影响。方法采用UPLC-QTRAP-MS/MS技术,以ACQUITY UPLC?HSS T3(100 mm×2.1 mm,1.8μm)色谱柱分离,0.1%甲酸溶液(A相)-乙腈(B相)为流动相;梯度洗脱,柱温35℃,流量0.2 mL·min-1,多反应离子监测模式同时测定乌药叶10个成分,结合方差分析、聚类热图、熵权TOPSIS和灰色关联法对不同干燥方式后乌药叶多元化学成分进行综合评价。结果10个成分在一定的浓度范围内线性良好,相关系数均>0.9916;仪器精密度、方法重复性和供试品稳定性良好,RSD均<5%;加样回收率在99.13%~103.07%,RSD值均<5%。方差分析表明不同干燥方式后乌药叶6个成分差异具有统计学意义(P<0.05);聚类热图结果显示经不同干燥方式后各成分呈明显聚集趋势;TOPSIS与灰色关联法分析结果基本一致,最终经阴凉通风摊晾干燥处理后成分保留效果最佳。结论所建立的方法准确、可靠,可为乌药叶适宜的加工方式和品质规范化生产提供参考。
